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Group 9Charlie GrubbsDaniel LanzoneMike RoosaRyan Tochtermann

Surveillance BotOverviewGoalsMotivationTo create a scalable all-terrain remote surveillance system with stabilization platformAudio detection capable of monitoring stereo sound levelsReal-time video linkIntuitive user-interfaceRoboticsSystems IntegrationScalability

ObjectivesVehicle can operate at a minimum of 4 MPH for at least 30 minutesCamera stabilization platform capable of correction at a rate of 50 HzPitch and roll correction of 45 deg. and a minimum of 60 deg/s correction rateStereo audio detection up to 10kHz Wireless communication of at least 100 yards outdoorsControl via PC based GUI

Vehicle Chassis OverviewCapable of moving over semi-rugged terrain (unlevel, rocky, grassy)Capable of overcoming ramped obstacles (< 35)Moderate suspension for Z-axis stabilization4 mphLow profile for stability

Vehicle Chassis : SuspensionTwo passive shock absorbers on each front wheelOne passive shock absorber for rear axis

Vehicle Chassis: MotorsSteering Motor50 RPM12 VDC ratingHigh torque gear boxBuilt-in potentiometer for position sensingDrive Motor2500 RPM12 VDC ratingDirect driveVehicle Chassis: Motor ControllerTwo bidirectional motor portsDriver: L298 Dual H-Bridge ICControl: 3 digital pins per motor: 1 for enable, and 2 for motor direction6- 35 VDC RegulationUp to 2A Output

Stabilization PlatformStabilization RequirementsWill provide pitch and roll stabilization for the mounted equipment (i.e. camera)Correction rate of 50 Hz10 W peak power consumption (pitch and roll servos)Platform does not change the CG significantlyInertial Measurement Unit (IMU)Sensitivity 250, 500, 1000, and 2000dpsSmall form-factor (4x4x0.9mm QFN)Low power consumptionLow driftSensor Decision MatrixPart NumberAxesTypeSizePriceITG-32003GyroscopeSmall$24.95ITG-3200 BO3GyroscopeLarge$49.95MPU-60503Accelerometer/GyroscopeLarge$39.959DOF Razor3Accelerometer/Gyroscope/ MagnetometerLarge$124.95IDG12152GyroscopeSmall$24.50Microcontroller Decision

ModelInput VoltageI/O PinsFrequencyCPUFlashATmega25601.8-5.5V8616MHz (Max)8-bits256KB ATmega16U22.7-5.5V2216MHZ(Max)8-bits16KBATmega3281.8-5.5V2320MHZ(Max)8-bits32KB

Stabilization SoftwareControlled by ATMega328Microcontroller will be used to implement the PID and Kalman filter algorithmsKalman filter will be used as sensor fusion between accelerometer and gyroscopeStabilization software

Hitec HS-5485 Servo motorsControls:PitchRoll3.3 V to 6 V60 deg in .18 seconds (no load)Mass: 59.82gDimensions: 40.39mm x 19.56mm x 37.59mm180 degree resolution

17Wireless cameraCamera requirementsCisco-Linksys Wireless-N320x240 resolutionIP camera15 FPS

640x480 max resolutionMJPEG streamMicrophone30 FPS5V Barrel-jack inputCamera TestingCamera tested at a peak bandwidth 1.2 Mbps with highest image quality setting and 30 FPSConfigured as an Ad-hoc network, the latency was reduced significantlyAudio Detection SystemOverviewStereo detectionTwo microphones shock mounted to chassis, facing east and westTwo stage signal amplification chainDSP on ATmega328Wireless communication via XbeeUser alerted via the GUIMicrophone SpecsLogitech desktop microphoneGenerates peak of ~1.5mVModificationsShielding

Analog Onboard Audio Signal ProcessingMicrophone connection to PCBAmplifier LM386Two gain stagesGain of 2500Small signal

GUIVisual Design

Sound Level / Notification CorrespondenceDecibel Level Examples TableSPLExampleNotification Level0 dBThreshold of Human Hearing 010 dBRustling of Leaves020 dBHuman whisper040 dBAmbient Noise in a Library050 dBQuiet Human Conversation160 dBNormal Human Conversation270 dBBusy Street Traffic380 dBVacuum Cleaner3100 dBLarge Orchestra3SPL Input / Output Voltage CorrespondenceSPL Input (dB )Voltage Output (mV)Voltage Output (dBV)Gain Adjusted Voltage Output (V)0~ 0 100 (Noise Floor)010~ 0 -100020 ~ 0 -100030 ~ 0 -100040 0.04-900.10650 0.14-800.35360 0.42 -701.061701.41 (Max Sensitivity)-603.535801.41 -603.535SPL Input / Output Voltage Correspondence

SPL Input (dB)GainAdj.Voltage(V)Sound Level / Notification Correspondence

GainAdj.Voltage(V)SPL Input (dB)Level 00V to 0.353VSound Level / Notification Correspondence

GainAdj.Voltage(V)SPL Input (dB)Level 10.353V to 1.061VSound Level / Notification Correspondence

GainAdj.Voltage(V)SPL Input (dB)Level 21.061V to 3.535VSound Level / Notification Correspondence

GainAdj.Voltage(V)SPL Input (dB)Level 33.353VMicrocontroller InterfacinganalogRead()Maps input voltages from 0 V to 5 VWill use full resolution of 4.8 mV (10 bit)Software/ProgrammingLoop that constantly checks input voltage from microphoneChanges output based on notification level

Communication SystemsCommunications System OverviewCapable of reliable and accurate data transmissionRelatively long range (100+ yards)Low power consumptionRelatively simple setup and configurationLow cost

Communications System OverviewThe goal is to create a network between the PC and the vehicle in order to send control and sensor data between them. It will feature a PC-side and embedded-side system, each consisting of a wireless RF module and a regulated serial interface between the module and the PC or onboard microcontroller.

XBee Series 2 RF ModulesKey Features:3.3V @ 40mA operationData rates up to 250 kb/s400 ft (133.33 yd) rangePros:Long rangeLow power consumptionLow costCons:For Series 2 modules; difficult to configure for point-to-point communication

Xbee Series 2 Module 2mW Antenna ModelEmbedded-Side InterfacingBecause the XBee operates at 3.3 V and the AtMega328 operates at 5 V, a voltage regulator is required for VCC input.A level-shifting diode is also required on the Xbees Data In line to account for this voltage difference.Other pins are connected to the microcontroller accordingly.

Embedded-Side DevelopmentThe Arduino XBee Shield is a simple interface between wireless module and microcontrollerTakes care of all voltage regulation, I/O connections, and status LEDsStill allows access to all other Arduino pins

Development/Testing using Arduinos XBee ShieldPC-Side InterfacingAn XBee Explorer USB will be used to connect the other XBee module to the PC.The device uses an FT232RL USB to RS-232 serial UART to interface between the XBee and the PC.Takes care of voltage regulation and I/O connections for easy development and testing.RS-232 to USB connection via XBee Explorer

Successes and DifficultiesDifficulties:Getting the Series 2 XBee modules to talk quickly and reliably.

Solution: Module is configured to broadcast mode for mesh networks by default. Must be changed to have only one destination node every time it is powered up.

Successes:Established a reliable wireless network.Sent and received messages between microcontroller and PCWireless drive control of surveillance vehicle for over 100 yards.Sensor data acquired for over 100 yards.

Control Software OverviewEmbedded-Side SoftwareMust receive user control data and respond accordinglyMust relay sensor data to PC-side softwarePC-Side SoftwareSimple GUI for complete control and current status of surveillance vehicleMust receive sensor data and display it in a simple formatMust transmit user control data quickly

PC-Side Software: GUIFeatures:Centered image of IP webcam feedSound detection indicators on left and right side of imageVehicle drive controlsCamera positioning controls Enable/disable stabilization option

Sketch of a desired GUI LayoutPC-Side Software: Processing IDEHigh-compatibility with Arduino platformSimple graphical user interface designUseful libraries:Controlp5 library for GUI componentsVideo library for webcam streamSerial library for communications

Sample GUI written in ProcessingPC-Side Software: UML Diagram

Embedded-Side SoftwareWill be programmed in the Arduino IDEWill utilize the Serial library for read/write communicationsWill have the following functionality:Read input values and send control data to the motor controllerWrite sensor data to the PC-side software to be displayed on the GUIPower SystemPower OverviewDeviceVoltageCurrent DrawPower QuantityATmega3285V9mA900mW2MPU-60503.3V3.9mA12.87mW1Servo Motors5V1A15W3XBee3.3V40mA132mWAmplifiers5V4Camera5V1A5W1Motor Controller11.1V2A /Channel22.2W /Channel1Power SupplyTenergy 11.1V LIPO Battery Pack5500mAh148 x 52 x 23 mm333 grams

5V Voltage Regulation75% Efficiency 3A output 4V to 40V input range5-pin through-holeLM2576

3.3V Voltage RegulationLM109 Linear RegulatorTL2575 Buck ConverterPros:Easy to useSmall PCB footprint Additional components unnecessary Cons:Heatsinking requiredLow efficiency

Pros:88% Efficiency Heatsinking not requiredHigher output current Cons:Requires additional componentsCost

Voltage RegulationLinearSwitching

Current SensingISL28006 used in conjunction with .0002, 5W shunt resistor

Current SensingISL28006 Specs60 uA power consumptionPower supply range from 2.7V to 28V100V/V GainUni-directional

57Voltage SensingATmega328 10-bit ADC pinScale input voltage to 5V

BudgetPartQtyProjected CostActual CostChassis1$85.00$0.00Arduino Uno Dev Board2$59.90$29.95MPU-60501$39.95$39.95XBee Explorer USB1$24.95$24.95XBee Shield1$29.95$29.95XBee Series 2 2$50.90$25.95Motor Controller1$34.95$34.95Battery /Charger1$79.94$79.94PCB2$160.00$160.00Bracket set1$19.00$19.00HiTech 5845 servos3$137.85$0.00Voltage regulators2$10.00$10.00Current sensors2$6.00$0.00Audio components1$50.0$50.00Microphone2$16.00$16.00Cisco IP Camera1$100.00$100.00TOTAL$904.39675.54Questions?