sivaq - university of colorado boulder · mission statement: augment the capabilities of the parrot...

42
SIVAQ S ignal I ntegrity V erifying A utonomous Q uadrotor

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Page 1: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

SIVAQ Signal Integrity Verifying Autonomous Quadrotor

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

The Team

Brett Wiesman

Nick Brennan

Steve Gentile

Ross Hillery

Shane Meikle

Erin Overcash

Sean Rivera

Geoff Sissom

Matt Zhu

1

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Agenda

bull Objectives

bull Project description bull CONOPS

bull FBD

bull Requirements

bull Feasibility Studies

bull Further Testing

bull Questions

2

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Mission Statement Augment the capabilities of the Parrot AR Drone 20 such that it flies autonomously with a predetermined

flight path records data relays data and detects and responds to GPS Radio Frequency Interference (RFI)

Mission Objectives

Establish a system that can detect GPS signal interference

Install extended range communication hardware on the drone

Develop software for communication data processing and piloting of the drone by selecting waypoints on a map at a ground station[1]

3

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Highest Level of Success[2]

Autonomous quad rotor autopilot with

(a) GPS navigation system and signal integrity monitoring (b) ldquoReturn home capability

(c) Upgraded battery

(d) Custom housing and mechanical interface between electronics and vehicle (e) Extended-range 24GHz Wi-Fi communications device for transmission of

video data and last known position

(f) During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a 3600 m2 field

(g) 2D mapping of RFI area and photography to attempt to locate the RFI source (h) Interface for future additional sensor package

(i) Custom fuselage that improves efficiency while preserving center of gravity and structural integrity and ensures control algorithms will maintain stability New fuselage will house (a) (c) (e) and (h)

4

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Vehicle Hardware[3]

Memory DDcaR2 RAM

200 MHz clock

Wi-Fi Atheros AR61036 chipset

24 GHz Tx frequency

Forward facing camera

93

wide angle lens 720p

30fps recording speed

Motor Controller (x4)

USB port 400 Mbs

Downward facing camera

QVGA 64

diagonal lens

60 fps recording speed

Navboard

Altimeter Barometric pressure

sensor 10 Pa precision

Ultrasound 6 m precision

Accelerometer 3 axis

50 mg precision

Magnetometer 3 axis

6

precision

Motherboard

Motor (x4) Brushless

145 Watts 28500 RPM

Microball Berings

Nylatron Gears

IMU Invensense IMU-3000

Contains 3 axis gyro and input for 3-axis accelerometer

Microprocessor 32 bit ARM Cortex A8

1 GHz clock

Microprocessor 16 bit PIC

40 MHz clock

Battery Lithium Polymer

1000 mAh capacity

Solder Connection

Pin Connection

5

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 2: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

The Team

Brett Wiesman

Nick Brennan

Steve Gentile

Ross Hillery

Shane Meikle

Erin Overcash

Sean Rivera

Geoff Sissom

Matt Zhu

1

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Agenda

bull Objectives

bull Project description bull CONOPS

bull FBD

bull Requirements

bull Feasibility Studies

bull Further Testing

bull Questions

2

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Mission Statement Augment the capabilities of the Parrot AR Drone 20 such that it flies autonomously with a predetermined

flight path records data relays data and detects and responds to GPS Radio Frequency Interference (RFI)

Mission Objectives

Establish a system that can detect GPS signal interference

Install extended range communication hardware on the drone

Develop software for communication data processing and piloting of the drone by selecting waypoints on a map at a ground station[1]

3

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Highest Level of Success[2]

Autonomous quad rotor autopilot with

(a) GPS navigation system and signal integrity monitoring (b) ldquoReturn home capability

(c) Upgraded battery

(d) Custom housing and mechanical interface between electronics and vehicle (e) Extended-range 24GHz Wi-Fi communications device for transmission of

video data and last known position

(f) During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a 3600 m2 field

(g) 2D mapping of RFI area and photography to attempt to locate the RFI source (h) Interface for future additional sensor package

(i) Custom fuselage that improves efficiency while preserving center of gravity and structural integrity and ensures control algorithms will maintain stability New fuselage will house (a) (c) (e) and (h)

4

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Vehicle Hardware[3]

Memory DDcaR2 RAM

200 MHz clock

Wi-Fi Atheros AR61036 chipset

24 GHz Tx frequency

Forward facing camera

93

wide angle lens 720p

30fps recording speed

Motor Controller (x4)

USB port 400 Mbs

Downward facing camera

QVGA 64

diagonal lens

60 fps recording speed

Navboard

Altimeter Barometric pressure

sensor 10 Pa precision

Ultrasound 6 m precision

Accelerometer 3 axis

50 mg precision

Magnetometer 3 axis

6

precision

Motherboard

Motor (x4) Brushless

145 Watts 28500 RPM

Microball Berings

Nylatron Gears

IMU Invensense IMU-3000

Contains 3 axis gyro and input for 3-axis accelerometer

Microprocessor 32 bit ARM Cortex A8

1 GHz clock

Microprocessor 16 bit PIC

40 MHz clock

Battery Lithium Polymer

1000 mAh capacity

Solder Connection

Pin Connection

5

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 3: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Agenda

bull Objectives

bull Project description bull CONOPS

bull FBD

bull Requirements

bull Feasibility Studies

bull Further Testing

bull Questions

2

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Mission Statement Augment the capabilities of the Parrot AR Drone 20 such that it flies autonomously with a predetermined

flight path records data relays data and detects and responds to GPS Radio Frequency Interference (RFI)

Mission Objectives

Establish a system that can detect GPS signal interference

Install extended range communication hardware on the drone

Develop software for communication data processing and piloting of the drone by selecting waypoints on a map at a ground station[1]

3

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Highest Level of Success[2]

Autonomous quad rotor autopilot with

(a) GPS navigation system and signal integrity monitoring (b) ldquoReturn home capability

(c) Upgraded battery

(d) Custom housing and mechanical interface between electronics and vehicle (e) Extended-range 24GHz Wi-Fi communications device for transmission of

video data and last known position

(f) During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a 3600 m2 field

(g) 2D mapping of RFI area and photography to attempt to locate the RFI source (h) Interface for future additional sensor package

(i) Custom fuselage that improves efficiency while preserving center of gravity and structural integrity and ensures control algorithms will maintain stability New fuselage will house (a) (c) (e) and (h)

4

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Vehicle Hardware[3]

Memory DDcaR2 RAM

200 MHz clock

Wi-Fi Atheros AR61036 chipset

24 GHz Tx frequency

Forward facing camera

93

wide angle lens 720p

30fps recording speed

Motor Controller (x4)

USB port 400 Mbs

Downward facing camera

QVGA 64

diagonal lens

60 fps recording speed

Navboard

Altimeter Barometric pressure

sensor 10 Pa precision

Ultrasound 6 m precision

Accelerometer 3 axis

50 mg precision

Magnetometer 3 axis

6

precision

Motherboard

Motor (x4) Brushless

145 Watts 28500 RPM

Microball Berings

Nylatron Gears

IMU Invensense IMU-3000

Contains 3 axis gyro and input for 3-axis accelerometer

Microprocessor 32 bit ARM Cortex A8

1 GHz clock

Microprocessor 16 bit PIC

40 MHz clock

Battery Lithium Polymer

1000 mAh capacity

Solder Connection

Pin Connection

5

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 4: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Mission Statement Augment the capabilities of the Parrot AR Drone 20 such that it flies autonomously with a predetermined

flight path records data relays data and detects and responds to GPS Radio Frequency Interference (RFI)

Mission Objectives

Establish a system that can detect GPS signal interference

Install extended range communication hardware on the drone

Develop software for communication data processing and piloting of the drone by selecting waypoints on a map at a ground station[1]

3

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Highest Level of Success[2]

Autonomous quad rotor autopilot with

(a) GPS navigation system and signal integrity monitoring (b) ldquoReturn home capability

(c) Upgraded battery

(d) Custom housing and mechanical interface between electronics and vehicle (e) Extended-range 24GHz Wi-Fi communications device for transmission of

video data and last known position

(f) During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a 3600 m2 field

(g) 2D mapping of RFI area and photography to attempt to locate the RFI source (h) Interface for future additional sensor package

(i) Custom fuselage that improves efficiency while preserving center of gravity and structural integrity and ensures control algorithms will maintain stability New fuselage will house (a) (c) (e) and (h)

4

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Vehicle Hardware[3]

Memory DDcaR2 RAM

200 MHz clock

Wi-Fi Atheros AR61036 chipset

24 GHz Tx frequency

Forward facing camera

93

wide angle lens 720p

30fps recording speed

Motor Controller (x4)

USB port 400 Mbs

Downward facing camera

QVGA 64

diagonal lens

60 fps recording speed

Navboard

Altimeter Barometric pressure

sensor 10 Pa precision

Ultrasound 6 m precision

Accelerometer 3 axis

50 mg precision

Magnetometer 3 axis

6

precision

Motherboard

Motor (x4) Brushless

145 Watts 28500 RPM

Microball Berings

Nylatron Gears

IMU Invensense IMU-3000

Contains 3 axis gyro and input for 3-axis accelerometer

Microprocessor 32 bit ARM Cortex A8

1 GHz clock

Microprocessor 16 bit PIC

40 MHz clock

Battery Lithium Polymer

1000 mAh capacity

Solder Connection

Pin Connection

5

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 5: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Project Description

Highest Level of Success[2]

Autonomous quad rotor autopilot with

(a) GPS navigation system and signal integrity monitoring (b) ldquoReturn home capability

(c) Upgraded battery

(d) Custom housing and mechanical interface between electronics and vehicle (e) Extended-range 24GHz Wi-Fi communications device for transmission of

video data and last known position

(f) During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a 3600 m2 field

(g) 2D mapping of RFI area and photography to attempt to locate the RFI source (h) Interface for future additional sensor package

(i) Custom fuselage that improves efficiency while preserving center of gravity and structural integrity and ensures control algorithms will maintain stability New fuselage will house (a) (c) (e) and (h)

4

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Vehicle Hardware[3]

Memory DDcaR2 RAM

200 MHz clock

Wi-Fi Atheros AR61036 chipset

24 GHz Tx frequency

Forward facing camera

93

wide angle lens 720p

30fps recording speed

Motor Controller (x4)

USB port 400 Mbs

Downward facing camera

QVGA 64

diagonal lens

60 fps recording speed

Navboard

Altimeter Barometric pressure

sensor 10 Pa precision

Ultrasound 6 m precision

Accelerometer 3 axis

50 mg precision

Magnetometer 3 axis

6

precision

Motherboard

Motor (x4) Brushless

145 Watts 28500 RPM

Microball Berings

Nylatron Gears

IMU Invensense IMU-3000

Contains 3 axis gyro and input for 3-axis accelerometer

Microprocessor 32 bit ARM Cortex A8

1 GHz clock

Microprocessor 16 bit PIC

40 MHz clock

Battery Lithium Polymer

1000 mAh capacity

Solder Connection

Pin Connection

5

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 6: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Vehicle Hardware[3]

Memory DDcaR2 RAM

200 MHz clock

Wi-Fi Atheros AR61036 chipset

24 GHz Tx frequency

Forward facing camera

93

wide angle lens 720p

30fps recording speed

Motor Controller (x4)

USB port 400 Mbs

Downward facing camera

QVGA 64

diagonal lens

60 fps recording speed

Navboard

Altimeter Barometric pressure

sensor 10 Pa precision

Ultrasound 6 m precision

Accelerometer 3 axis

50 mg precision

Magnetometer 3 axis

6

precision

Motherboard

Motor (x4) Brushless

145 Watts 28500 RPM

Microball Berings

Nylatron Gears

IMU Invensense IMU-3000

Contains 3 axis gyro and input for 3-axis accelerometer

Microprocessor 32 bit ARM Cortex A8

1 GHz clock

Microprocessor 16 bit PIC

40 MHz clock

Battery Lithium Polymer

1000 mAh capacity

Solder Connection

Pin Connection

5

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 7: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Black Diagram

Hard DataPower Connection

Wireless Data Connection

Developed for Project

Pre-Existing Hardware

Motherboard

Wi-Fi

USB port

AR Drone 20

Navigation

Software

Vehicle Kill

Command

Dynamic

Waypoints

Wi-Fi GUI

Battery Autonomous

Navigation

Software

RFI Detection

Software RFI Simulation

Vehicle Modifications

GPS Antenna

GPS Receiver

Storage Device

Electronics Package

Thermistor

USB HubPort

6

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 8: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS

Loiter 1 minute and locate target using downward facing

camera Command

Destination and Waypoints for autonomous

travel

Begin flight with continuous signal

integrity monitoring and flight data transmission

Return home

Downlink and store flight data

in real time

Travel towards estimated

target location

7

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 9: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

CONOPS ndash Scenario 2

Continuous signal monitoring and

data transmission detection

Command Destination and Waypoints for autonomous

travel

Downlink and store flight data

in real time

Immediate powerful RFI detected Lose

Communication link with ground station

Abort mission disable GPS and

attempt to return home inertially

Immediate large radius RFI is

enabled

8

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 10: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

False GPS sphere of influence

CONOPS ndash Scenario 3

Command Destination and Waypoints for autonomous

travel False Signal Detected

Viable communication link with ground station

Attempt to map sphere of

influence or locate source of RFI

Continuous signal monitoring and

data transmission detection

Downlink and store flight data

in real time

9

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 11: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Functional Requirements[1]

REFERENCE Description

1QUADFR1 SIVAQ shall travel autonomously via predetermined waypoints while maintaining pseudo range accuracy of 78

meters (TBR) at 95 confidence level

1QUADFR2

SIVAQ shall monitor GPS information integrity and detect radio frequency interference Signal shall be

considered compromised if AGC level is greater than three from nominal AGC level

1QUADFR3 SIVAQ shall create map RFI zone of influence

1QUADFR4 SIVAQ shall return to ground station once mission is completed or at 30 (TBR) battery life remaining

1QUADFR5 SIVAQ shall be able to fly to a target location within a 3km radius area capture video data for 1 min then return

home

1QUADFR6 Finalized SIVAQ cost shall be less than $750 (TBR) in components

1QUADFR7 SIVAQ shall be operational in open terrain and in conditions of ideal weather (no precipitation and no wind)

1QUADFR8 SIVAQ shall be equipped with an extended range 24 GHz Wi-Fi two-way communications device

1QUADFR9 During 1 minute loiter SIVAQ will provide live video data such that the pilot can identify a red target 1 m2 in a

10000 m2 field

1GRNFR1 A GUI will allow the user to select waypoints and specify the vehicles mission Additionally the user will be able

to alter waypoints during flight

1GRNFR2 The command center must be able to receive and display data sent from the vehicle for processing

10

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 12: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Baseline Design Selections[1]

Subsystem Design Selection

RFI detection Automatic Gain Control signal monitoring

Mass and Power Structural modification and high capacity Li-Ion battery

Communications 24 GHz Wi-Fi antenna modification

Mission Data USB flash storage and Wi-Fi 80211n streaming

Control Software AutoPylot written in MATLAB

Navigation method GPS based waypoint navigation

GUI Software NASA WorldWind mapping software and Java Swing

11

CDD Design Solutions

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 13: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Feasibility Studies

Aspects of the project analyzed for feasibility

1 How will the vehicle detect and simulate RFI

2 Is 6 km range (3km out and back) possible given mass and power considerations

3 Can the vehicle maintain communication link with the ground station over 3km distance

4 Can vehicle accommodate required data transfer and storage rates

5 Does MATLAB have an acceptable response time for control software

6 Is waypoint style navigation possible with selected software

12

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 14: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

Automatic Gain Control

bull Automatic Gain Control (AGC) is an adaptive circuit which dynamically adjusts incoming signal gains to match the level requirement of downstream electronics[4]

bull AGC is low complexity and is intrinsic in all multi-bit GPS receivers

bull AGC is not part of NMEA message but some civilian GPS receivers include it in the digital output

bull GPS RFI can be detected by monitoring the output of the AGC circuitry bull A boosted GPS signal causes the

AGC to drop

13

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 15: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Detection Feasibility

bull A study conducted in Sweden[4] using a GPS RFI device showed that AGC can be used to accurately detect GPS RFI bull AGC output is monitored for a

drop below a predetermined threshold

bull This proves the feasibility of the AGC detection method

14

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 16: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AGC Signal Characterization

bull AGC levels are subject to noise from surroundings[3]

bull Refinements can be made to AGC measurements by accounting for thermal noise and other signals present in the frequency band

bull Noise can be characterized for the specific GPS module and flight conditions to properly detect active RFI

15 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 17: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - Noise Characterization

bull Ground and Flight models of the GPS modules will be bench tested and data will be logged using a data acquisition system

bull Tests will be run both on and off the UAV platform bull On-platform tests will be run with the vehicle off on and in

controlled flight

bull Results from this test will allow for the characterization of noise in the GPS signal for various conditions

Thermistor

16 RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 18: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI Ground Testing - L1 Injection

bull An L1 GPS signal simulator will be fed through a variable gain amplifier and injected into the GPS RF stream simulating a malicious RFI source

bull A data acquisition system will be used to monitor and log the AGC signal from the GPS module

bull This ground test will be used to characterize AGC response to an amplified signal in the L1 band and determine the appropriate threshold at which AGC will accurately denote GPS RFI

17

Thermistor

RFI Detection Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 19: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Waypoint-based RFI Simulation bull To implement RFI in flight (currently illegal) data from RFI ground tests are

used to create a software simulation which mimics the results of actual RFI on the AGC signal in the GPS modulersquos digital output

bull GPS waypoints are used to define the perimeter of the simulated RFI zone which when breached will result in simulated RFI manipulating the digital AGC signal

Nav Software

RFI Software

Thermistor

18 RFI Simulation Feasibility

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 20: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Customer Requirement ARDrone 20 shall fly 3 km from launch point loiter for 60 seconds then return 3 km to takeoff point ARDrone 20 Capabilities Manufacturer Claim 36 km max range (Cruise Speed 5 ms Flight Time 12 minutes) User Claim 225 km max range (Chuck Rossetti claims only Wi-Fi modifications) Drivers for Range Requirement bull Commercially available radio frequency interference devices have extremely

variable areas of influence (up to 6km) but the typical RFI device ldquozone of influencerdquo extends 2 to 500 meters from signal source

bull Extended range improves functionality of ARDrone 20 enables ability to map ldquozonerdquo of GPS corruption

bull Range improvement enables increased flexibility in future missions (Customer Request)

19

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 21: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

AR Drone Mass Budget

Required Components

Component Mass [g] Percent of Stock Mass []

Stock Outdoor Vehicle

424 10000

GPS ReceiverAntenna

20 472

4000 mAh Battery (Dynamite Speed Pack Silver)

225 4693

Polarized Antenna 11 259

USB 1 024

Magnetic Compass 014 003

Total Mass 68114 16065

Component Mass [g] Percent of Stock Mass []

Outdoor Hull

32 952

1000 mAh Battery

101 2405

Stickers 10 238

USB Port 5 119

Camera Arm

5 119

Total Mass 153 3833

Unrequired Components

Final Mass 52814 [g] 12456 [ of stock]

20

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 22: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

STEP 1 Find current during hover STEP 2 Find flight angle at designated speed

Weight

Ampshover

Thrust

A Battery Pack

Angle

Weight Thrust

Velocity

Estimating Current Draw

21

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 23: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis

Power Draw Estimation for 6 km distance and 3600 m2 scan

Component Current [Amps]

Battery Capacity [mAh]

Percent of 4000 mAh Battery []

GPS ReceiverAntenna 0075 3133 078

USB 0050 209 050

Flight 692 32831 8208

Scan 692 68 017

Battery Margin NA 8000 20

Total 7045 41421 10355

Stock hardware processing and telemetry of AR Drone 20 is included in flight and scan

The necessary battery capacity to complete the mission is larger than the heaviest allowed battery

22

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 24: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Range Feasibility Analysis B

atte

ry M

ass

[g]

Capacity [mAh]

0

0 5000

250

Battery Mass to Capacity Ratio Study

23

Design Area

Unfeasible Area

Needed to fulfill 6km requirement

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 25: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication

Requirements bull Vehicle must continuously transmit live video data to the ground station

bull A pilot at the ground station must be able to send vehicle ldquokillrdquo command (FAA Requirement)[5]

bull User must be able to dynamically change waypoints mid-flight

Vehicle is equipped to communicate via Wi-Fi bull Average Wi-Fi range over 80211 protocol is when outdoors

bull This will not reach the suggested travel distance of 3 km

bull The communication capability must be upgraded in some way in order to maintain a high quality data link at the suggested range

24

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 26: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Communication Modification

Antenna Modification bull Baseline communication range calculation

bull Normal Wi-Fi range 100m

bull Signal strength drops with range squared so for each doubling of range we need 6dB more signal gain the range must be doubled 5 times (30dB gain) in order to achieve 3km distance assuming no transmission loss

bull Further testing will be necessary to obtain transmission data from the vehicles antenna

bull Must also consider FCC regulations and may not exceed 1W (30dBm) TRP 4W (36dBm) EIRP

bull Highest gain commercially available omnidirectional antenna found was only 15 dB

For point-to-point link antenna gain can be increased to obtain EIRP gt 36dBm but for every 3dBi increase in antenna gain transmit power must be decreased 1dBm

bull 3km range cannot be obtained legally using omnidirectional antenna

bull Online user ldquoGarrockrdquo has created and provides detailed descriptions of what he labels a ldquoWheel Antenna Modrdquo [6] which modifies the vehicles built in antenna to increase the transmission capability to a range of 200m

bull Several users have successfully used the Itelite SRA24019 A 19 dBi directional gain antenna on the ground station to increase the range of the vehicle to a distance of 1 km [7]

25

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 27: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transfer and Storage

Requirement bull Data Storage

bull GPS integrity information location velocity heading IMU and other sensor data

bull Data Streaming bull Constant real time video

bull Kill command

bull GPS integrity information location velocity heading IMU and other sensor data

bull GPS Integrity Info

26

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 28: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Transmission Feasibility

Data Transmission Rates of On-Board Electronics

The vehicle will be able to transmit all necessary data to the ground station If Wi-Fi power drops below threshold streamed info will be buffered but still

come through

27

Invensense IMU ndash 3000

Front Facing Camera

Down Facing Camera

GPS Battery Levels

Needed Data Rate

Atheros AR 61036

Capability[3]

Data Rates

2 MBs∆ 05 MBs 0167 MBsΩ 0075 MBs 1 MBs∆ 374 MBs 1 MBs ndash 9 MBs

Values used in table represent upper limit of data rates found in research ∆ Functions of sampling rate (IMU sampling at 32 ms)

Ω Assumed to be 13 of front facing camera because resolution is 120p at 60 fps vs front facing camerarsquos 720p at 30 fps Further testing is required to verify resolution Average used as Wi-Fi data sheet reads Further testing required to verify

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 29: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Data Storage Feasibility

Data rate excludes video ndash not being stored Assuming a 20 minute flight

Data Storage for On-Board Electronics

Required Data Rate

Required Storage Capacity

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Write Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive

Read Speed

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive Capacity

3075 MBs 4 GB 14 MBs 27 MBs 16 GB

Verbatim Tuff-lsquoNrsquo-Tiny USB Drive only weighs 1 g[8] by far the lighted storage device found to meet project storage needs

USB Drive can store approximately 80 min of flight data 4 x faster than the necessary data rate

28

Additionally the onboard ARM Cortex A8 is capable of writing at 20 MBs over USB[12]

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 30: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Onboard Software Requirement

bull On-board software must allow for autonomous waypoint navigation

bull Must integrate the AR Dronersquos control algorithms

bull Team familiarity more important than performance

AutoPylot Control Software bull FreeOpen Source

bull C Python and MATLAB integration

bull Runs using AR Dronersquos control algorithms

Language Performance (MIPS)

Threading Estimated Response Time [msMega-Instruction]

C 2000 Yes 5

Python 400[9] No 25

MATLAB 300[2] Yes 333

bull MATLAB compiled to binary using MEx to run on vehicle bull AutoPylot with MATLAB chosen for familiarity with language has acceptable

response delay

29

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 31: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation 30

AutoPylot[13]

bull Developed for 64-bit Linux

bull Compiles ARDrone 20 SDK using latest vehicle firmware bull Preserves Parrot calibrated control algorithms

bull Capable of working with with MATLAB using Mex to compile binaries

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 32: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Autonomous Waypoint Navigation

U e D G

W

Y +

-

+

+

bull Parrot currently manufactures and sells its own GPS module thus the latest vehicle firmware is already capable of interpreting GPS signal data

bull AutoPylot uses a ldquocommandsrdquo matrix that it sends to the vehicles onboard processing unit

bull The commands matrix contains values for roll pitch yaw zap and gaz that move the vehicle

bull A transformation that creates these commands from GPS position will need to be developed

bull Waypoint navigation with the AR Drone 20 has been successfully completed by several users and institutions including the Delft University of Technology [10]

bull Waypoint Navigation is Feasible

Variable Description

U Destination (Lat Lon Alt)

e Error between current and desired position

D AutoPylot control commands (zap phi theta gaz psi)

G Vehicle built in dynamics and flight control

W External disturbances altering position (wind)

Y Current location (Lat Lon Alt)

31

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 33: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Software

The GUI must bull Allow user to select waypoints by clicking on a map

These waypoints are then communicated to the vehicle real-time and can be changed mid-flight

bull Display real time video data streamed from the vehicle

bull Enable quick use of a ldquokillrdquo command

bull Allow user to monitor telemetry data (battery life location velocity connectivity GPS integrity)

bull NASArsquos WorldWind was selected for API support and team familiarity with Java bull Alternative is currently Marble (uses Python)

32

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 34: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

GUI Mockup 33

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 35: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Further Feasibility Studies

bull Determine if navigation with vehiclersquos IMU and other sensors bring vehicle ldquohomerdquo within acceptable error without the aid of GPS

bull Determine most efficient RFI mapping method

34

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 36: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Navigation Without GPS

Customer Requirement ARDrone 20 shall be able to return home when GPS signal integrity is compromised using a secondary navigation system Solution The ARDronersquos velocity measurements will be integrated in both horizontal axes to calculate the ARDronersquos position This will then be used for navigation back to the home base

Known GPS

Lat 405843

N

Lon 1049212

W

X 1243 M

Y 345 M

Last Known GPS

Lat 400176

N

Lon 1052797

W

X 0 m

Y 0 m

Vy

Vx

35

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 37: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Inertial Navigation Testing 36

[15]

bull Assuming 3 km path traveled at 4 ms and 05 ms error distance error would accumulate to 375 m

Test Method Flight test logging GPS and IMU data and compare

Time [s]

Spee

d [

ms

]

Method AR Drone calculates velocity by integrating accelerometer measurements corrected by down-facing camera Precision of accelerometers is added to the steady accuracy of the camera to provide a velocity solution that does not compound error and a position solution that compounds linearly rather than exponentially

Velocity Estimation

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 38: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

RFI zone of influence mapping

bull Mapping technique is going to depend highly upon AGC lab measurements as well as onboard processor availability

bull Lab testing will need to determine nominal AGC value as well as necessary change that corresponds to RFI

bull Once this is known appropriate mapping algorithm will be developed

bull In addition to mapping technique minimizing total distance traveled without sacrificing map accuracy is desired

37

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 39: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

38 RFI Mapping preliminary CONOPS

AGC threshold crossed Store

last known good location

AGC level returned above

threshold Store location

D2 lt D1Mapping completed return

home

d2

AGC value again trusted store

latitude distance between good

locations d1

38

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 40: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

39 Feasibility Summary

Subsystem Feasible Reason

RFI Yes Previous testing demonstrated feasibility

Mass and Power No MATLAB model showed unfeasibility with commercially available batteries

Communications No Cannot reach required range legally using 24GHz Wi-Fi

Storage and Data Yes Worst case analysis still within bandwidth

Software Yes Delay using MATLAB is less then human noticeable delay

Navigation Yes Previous work with AR Drone 20 demonstrated waypoint travel

GUI Software Yes NASA WorldWind capable of interfacing with Java

39

bull 3km range requirement will need to be reassessed with customer

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 41: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

Intro Project Description Feasibility Analysis Moving Ahead Conclusion

Conclusion

Areas of concern

bull 3km range requirement is large affects power mass and communication feasibility and the reason for its existence is unclear

bull Inertial sensor navigation introduces large error and will require extensive testing to understand ldquoreturn to homerdquo feasibility

Overall Project feasibility

The proposed project will be feasible if the range requirement can be reduced

40

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]

Page 42: SIVAQ - University of Colorado Boulder · Mission Statement: Augment the capabilities of the Parrot AR Drone 2.0 such that it flies autonomously with a predetermined flight path,

References 41

[1] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Conceptual Design Documentrdquo University of Colorado Department of Aerospace Engineering 30SEP2013

[2] Brennan Gentile Hillery Miekle Overcash Rivera Sissom Wiesman Zhu ldquoSIVAQ Project Definition Documentrdquo University of Colorado Department of Aerospace Engineering 23SEP2013

[3] ldquoTechnical Specifications State of the Art Technologyrdquo Parrot AR Drone 20 [httpardrone2parrotcomardrone-2specifications]

[4] Akos D M ldquoWhorsquos afraid of the spoofer GPSGNSS spoofing detection via automatic gain control (AGC)rdquo Navigation 59(4)281ndash290 2012

[5] ldquoCOA Notesrdquo 19SEP2013 [httpsrecuv-opscoloradoeduprojectsfaa_coawikiHow-to-Obtain-a-COA]

[6] Garrock ldquoWheel Antenna Mod ndash Significant Wifi Performance Upgraderdquo Parrot AR Drone amp AR Drone 20 Forum 18JUL2012 [httpforumparrotcomardroneenviewtopicphpid=6721]

[7] Parrot AR Drone amp AR Drone 20 Forum [httpforumparrotcomardroneenviewtopicphpid=6721]

[8] Verbatim USB Storage Website ldquo16GB - TUFF-N-TINYtrade USB Driverdquo Copyright copy2013 [httpwwwverbatimcomprodusb-driveseveryday-usb-drivestuff-n-tiny-sku-97168]

[9] ldquoPyPy Speed Centerrdquo [httpspeedpypyorg]

[10] Full Blown Hucker ldquoTU Delft ndash Search and Rescue with AR Drone 2rdquo MultiRotorForumscom OCT2012 [httpwwwmultirotorforumscomshowthreadphp9288-TU-Delft-96-Search-and-Rescue-with-AR-Drone-2amps=f93bdfa922cee6524313f08fe267be6800]

[11] Bristeau P J Callou F Vissiegravere D Peiti N ldquoThe Navigation and Control technology inside the ARDrone micro UAVrdquo [httpcasensmpfr~petitpapersifac11pjbpdf]

[12] Texas Instruments ldquoAM335x-PSP 04060008 Features and Performance Guiderdquo [httpprocessorswikiticomindexphpAM335x-PSP_04060008_Features_and_Performance_GuideEthernet_Driver]

[13] Levys ldquoARDrone AutoPylotrdquo [httphomewluedu~levyssoftwareardrone_autopylot]