Team Sasquatch

MAE 4894/1/13

Alex Lee Josh AndersonNick UphamVincent VelardeRod NezRyan Doyle(Left to Right)

To create a stable aerial platform for use in forensic engineering.

• Stable• Reliable• Capable of video recording

Problem Statement

SolutionElectrical Components Housing:Controller, Receiver, Sensors

Batteries (2)Arch (2)

Electrical Speed Controller (4)

Arms (4)

Propeller (4)

Connector Rods (2)

Camera Mount Point

Motors (4)

Requirement Validation MatrixRequirements Validation

Frame- less than 0.1 inches deflection Analysis

Center of Gravity in Center of Frame Inspection

Settling Time less than 5 seconds Analysis and Inspection

Overshoot less than 10% Analysis and Inspection

Sampling period less than 0.04 seconds Inspection

Ability to maintain flight in 10 Mph winds Analysis and Inspection

Quality Video Inspection

300 Foot radio range Testing

3 pound minimum payload capacity Analysis and testing

2 year fatigue life Analysis

100 Newton impact force for frame Analysis

Key Characteristics

• Propellers and motors provide thrust• Powered by LiPo batteries • Stability provided by microcontroller and

sensors• Durable frame

Key Characteristics

Recording

Flight

Thrust

Propulsion

Control

Stability and Response Sensing Command

Electrical Power Frame

Design Process

• Research of prior art showed that multi-rotor craft were most suitable to meet the requirements.

• Further analysis amongst multi-rotor crafts, ranging from three to six rotors, showed that a four rotored craft, or quadcoptor, held the ideal mix of thrust, flight time, and stability.

Project Metrics

Project Metrics

Labor Budget 488

Labor Budget 489

0 2 4 6 8 10 12 14 160

100

200

300

400

500

600

700

800

900

Labor Budget vs. Actuals

Cumulative BudgetActual Budget

Week

Hour

s Wor

ked

Material CostsITEM Budgeted Cost ($) Actual Cost ($)

Motors 80 TBD

ESC’s 80 TBD

Propellers 40 TBD

Microcontrollers 40 TBD

Sensors (IMU, Compass, Altimeter, Proximity)

100 TBD

Wireless Communications 60 TBD

Hand Controller 50 TBD

Power Supply 50 TBD

Frame Materials 160 TBD

Control System Test Stand 50 TBD

Wireless Video System 100 TBD

Fasteners, Wires, and Connectors 20 TBD

Total 780 TBD

Conceptual Design

• Research of Prior Art– “Design and Control of Quadrotors with

Application to Autonomous flying”– Available micro controllers and sensors.– Research into batteries and electric motors.

Conceptual Design

• Candidate Concepts– Single Rotor

– Tri Rotor

– Quad Rotor

– Hex Rotor

Conceptual Design

Preliminary Design Trade StudiesFrame Material• Carbon Fiber• Aluminum• Titanium• Steel

Microcontroller• Arudino Uno• Arduino Mega• Arduino System• PIC

Controller• Bluetooth• Xigbee• RF

Battery Type• LiPo• NiMH• LiFe• NiCad

Motor• Turnigy D3536/9• NTM 35-30• AX-2810Q• ICE

Control Approach• PD• PID• PI

Propeller• 12 x 3.8• 12 x 4.5• 12 x 6• 12 x 8• Slow Fly

Preliminary Design Work Plan

Thrust Analysis

Propeller and Motor Trade

POC Test

Hardware Selection

Battery Analysis

Microcontroller Trade Study

POC Testing of Controls

Hardware Selection

Battery Trade Study

Hardware Selection

Frame Analysis

Frame Design

FEA

Optimization

Analysis Plan:Frame

Frame

Skids Hand Calcs FEA

Motor Hand Calcs POC Testing

Structure Hand CalcsFatigue Matlab

calcs

Deflection FEA

Analysis Plan:Control Systems

Controls

Battery Power Requirements Flight Time POC Testing

Microcontroller PID Testing POC Testing

System Modeling

Simplify System

PID Transfer Function

Response Analysis

Trade Study Example: Microcontroller

Criteria Option A Option B Option C Option D

Cost Approx. $25 $35 $45 $60

Memory 32 Kb 512 Mb 128 Kb 256 Kb

Programming Any Linux/Python Arduino/C++ Arduino/C++

Hardware Compatibility

14 I/O pins6 Analog6 PWM

18 I/O PinsHDMI

39 I/O pins 16 Analog15 PWM

54 I/O pins16 Analog14 PWM

User support Low to moderate Moderate Moderately High High

Issue: Reads sensor data, derives error, uses control algorithm to develop a response

Options: A. In-house AssemblyB. Raspberry PiC. MapleD. Arduino

The final selection is a specialized Arduino which is very cost effective.

Trade Study Example: Motor

Criteria Option A Option B Option C

Power (Watts) 370 350 333

Draw (Amps) 25.5 32 30

Weight (grams) 102 88 70

Issue: Providing thrust for the system.

Options: A. Turnigy D3536/9 B. NTM 35-30 C. AX-2810Q

Option A was selected because it has the lowest draw which is the most important criteria while also having no major disadvantages. Although Option A is the heaviest, having the least draw allows for optimized weight saving by the use of lighter, smaller batteries.

Analysis Example: Fatigue

Problem Statement: Cyclic loadings will cause yielding or fracture within the arms with extended use throughout the life of the arm.  Approach: Decrease deflection and stress from their primary source, the motor arms. Use modified Goodman Equation. Approximate the endurance limit as . Assumptions: Cantilever beam model, Assumed maximum theoretical loading conditions. The cyclic loadings consists of , which is the force the arm will experience from the lift of the motors, and , the force applied by the weight of the motor. The distributed weight of the aluminum arm was considered negligible.  

 Defining Equations:

 Results: Due to the miniscule forces applied to the arms by the lift from the motor and the weight of the motor, failure by fatigue will not occur. The factor of safety for infinite life for aluminum () is 26.  Conclusion:  Fatigue failure is not a concern.

Recommendations: None 

Example POC Testing

Purpose of test:Find thrust for

motor and propeller and

flight time

Results: Performance not as expected

Conclusions: Need to redesign test

Effect on design: Battery sizing

Continued POC Testing

Purpose of Test: Repeat Thrust test to find flight time

and loading.Results: Performance as

expectedConclusions: Results valid

Effect on: Battery sizing, forces on frame, and flight time

established

FMEA - SummaryFailure mode

Probability of Failure

End Effect SeverityDetection Method

Ability to detect

Initial RPN

Reduction MethodNew

ProbabilityNew RPN

Fatigue 3Structural

failure8

Operator Observation

9 216 Fatigue analysis 1 72

Power Failure 6Loss of flight capabilities

9.5Operator

Observation5 285

Feedback and quality and Testing

4 190

ESC Failure 4Loss of flight capabilities

9Operator

Observation10 360 Quality ESC's 2 180

Landing skid failure

5Structural damage

6Operator

Observation7 210 Analysis 3 126

Microcontroller Failure

2Loss of Control

10Loss of Control

9 180Quality

microcontroller1 90

Goal Function Optimization:Cost

Initial Estimate

Began Pricing

Frame reduction and better vendors

• Change batteries• Changed camera• Made of carbon fiber

1 2 3 4 5 6 7 8 9 10 11200

400

600

800

1000

1200

CostBudget

Week Number

Cost

($)

Goal Function Optimization:Flight Time

Incorrect Battery

Changed Battery

Lightening Frame

1 2 3 4 5 6 7 8 9 10 110

5

10

15

20

25

30

Flight Time Estimate

Flight Requirement

Week Number

Flig

ht T

ime

(min

)

Solid Model—Final DesignElectrical Components Housing:Controller, Receiver, Sensors

Batteries (2)Arch (2)

Electrical Speed Controller (4)

Arms (4)

Propeller (4)

Connector Rods (2)

Camera Mount Point

Motors (4)

Detail Design

Structural Assembly

Motor Assembly

Propellers Motors

Frame Assembly

Body Assembly

Central Node Arms Top Plate Fasteners

Landing Assembly

Skids Assembly

Connector Rods Arches

Bottom Plate

Detail Design

Controls Assembly

On-Board Controller

Altimeter Arduino Mega 6-Axis IMU Proximity

Sensor Compass XBee

Ground Controller

XBee LCD Screen Control Sticks

Arduino Uno

Power System

Batteries ESCs

Manufacturing Biggest Challenges

• Inaccurate machine shop lead times• No prior knowledge of machining or soldering• No workshop space to store and assemble • Lack of fabrication equipment

Manufacturing

Manufacturing

Development Challenges

• Budget

• Long Lead Hardware

• Hardware Failures

• Difficult Analysis

Hardware Failures

• Hardware failures posed a major problem during the development process.

• ESC failures• Microcontroller failure.• Wire connector failure.• Motor failure.

Validation Summary

• > 0.1 in. deflection (pic of ANSYS)• CG in center of frame (Solidworks output)• 3 lb. minimum payload (thrust test

results)• Settling Time <5 seconds (for these

MATLAB output)• Overshoot <10%• Sampling period <.04 seconds

Validation Summary

• Maintain flight in 10 MPH winds (test results)• Quality Video

(inspection)• 300 ft. radio range (testing)• 2 year fatigue life (analysis)• 100 N impact force (analysis)

Project summary

• Quadcopter stable aerial video footage • Best hardware selection • Designed and optimized frame • Developed own controls system• Integrated design components • Achieved successful flight

Success factors

• Twice a week meetings• Decisions based upon vote• Team strived for optimum output with

feasibility• Detailed pre-planning

Lessons Learned

• Get machining parts into shop early and monitor very regularly

• Provide ample time to test hardware • Budget time correctly for hardware failures