Sean Day Diante Reid Liem Huynh

Project Overview  To create a vehicle that autonomously follows a moving object  To design a low cost, mobile robot that can track objects based on image processing  Implement all of the parts using the Atmel microcontroller  Fire at target object when specified

Requirements  Autonomously track and follow a moving object using color detection  Operate on battery power and not other external source of power  Keep a minimum of 7 inches away from it target at all time.  Operate both indoor and outdoor  Operate for more than one hour on a fully charged battery.  Have a dimension of no more than 14x7x7 inches

Optional Features  Autonomous weapons system  Solar Power  The AVR shall be able to communicate and upload telemetry data to the user via Bluetooth  The AVR shall be able to map its surrounding and navigate to a designated target with GPS.

Top Level Diagram CMUCam2+ Maxbotix LV-EZ2 IR Detector Sensors Manage r Guidance, Navigation and Control Actuators Environment Images Ultrasonic Signals Encoder Patterns On- Off Pulse s PWM Centroid and Servo Location Target Location Target Range Chassis Velocity PWM Software Hardware Environment Target

Microcontroller - Arduino  ATMEGA328  USB Interface  Cross-platform  Easy to program  Open source  Well documented

Printed Circuit Board  PCB123 software  $100 student credit from sunstone  Prototyped on the Arduino board  2 layer design  Using through hole and surface mount techniques

CMUcam 2+ Vision Sensor Performs image processing duties for AVR Track user defined color blobs at up to 50 Frames Per Second (frame rate depends on resolution and window size settings) Track motion using frame differencing at 26 Frames Per Second Find the centroid of any tracking data Gather mean color and variance data Gather a 28 bin histogram of each color channel Process Horizontally Edge Filtered Images

Image Processing Requirements  Color detection  Motion detection  Flexibility for programming  Ability to distinguish between specified color and other colors in environment  Work efficiently in well lit environment

Image Processing Techniques  Edge Detection  Canny detection  Edges are areas where a jump in intensity from one pixel to the next occurs  Able to reduce the amount of data processed by filtering out useless information

Blob Detection  Middle Mass  Determines if a group of connecting pixels are related to each other by surroundings  Efficient in identifying separate objects in a scene

CMOS vs. CCD Sensor CMOSCCD  Transistor based  Flexible design  Average picture quality  Low power consumption  Low Price  Analog device  Rigid design  Excellent picture quality  Power hungry  Very Expensive

Choosing a Vision System  CMUcam1  CMUcam2  CMUcam3  AVRcam  Logitech QuickCam Orbit AF Webcam + RoboRealm

CMUcam Comparison PriceFrame RateResolutionRAMROMSPEED CMUcam1$ fps80x bytes2048 words75 MHz CMUcam2$ fps176 x bytes4096 words75 MHz CMUcam3$ fps352x28864 KB128 KB60MHz AVRcam$ fps88x bytes512bytes16MHZ

CMUcam2+ Software  Open Source Programmable  Hybrid Version of C Language  CMUcamGUI

Why CMUcam2+  Compact Size  Frame Buffering  Affordable price  Flexible  Multiple Servo Control  User Support

Power Needs Voltsmilliamps Ultrasonic Sensor Motor Steering Servo 3-65x1 CMU Camera mA CMU servos3-65x1

Voltage Regulation  All parts on AVR can run off of 5volts DC  Stepping Down 7.4 volt battery  LM317 adjustable regulator

Ultrasonic Sensor Requirements  Purpose is to keep AVR within 6 inches of target object  Be able to fit on front bumper  Will not loose the target object  Low power consumption

Maxbotics Ultrasonic Sensor  Maxbotics EZ1  Will easily fit on bumper  Only draws 2mA of current  Easy to interface

Interfacing the Sensor  Pulse Width Modulation  147 microseconds/inch  Analog Input  (Vcc/512)/inch

Batteries

Chassis  RC car from ToysRus  4 wheels  2 front turning wheels  2 rear wheels for going back and forward  2 DC motors  Roomy

Servos  DC Motors  RC Servos  Stepper Motors

Sensors Manager  getRange()  Returns range from Ultrasonic Sensor in inches  getVelocity()  Returns velocity from IR detector/reflector in inches/seconds  getCentroid()  Returns centroid location of target in x and y format

Sensors Manager  getPan()  Returns location of panning servo  getTilt()  Returns location of tilting servo  getTime()  Returns microprocessor’s time

GNC  Determine velocity using the encoder wheel and IR detector/reflector

GNC  Tracking the target’s centroid 14488

GNC  CMUcam to Body alignment  Body Frame, CMUcam Frame β Servo Positions 128, 0° 210, 90°46, -90° β Servo PosOffset -90 ° °0° ° Offset = 44 sin( β ) Centroid_B = Centroid_C + Offset

GNC Initialization Forward Straight Locate Centroid Forward Right yes no Target’ s range <=5 inches? Centroid > 54 Forward Left Centroid < 34 else Stop Navigation Flowchart

GNC P (Range) D (Velocity) Plant InputOutput Error Proportional-Derivative Controller Variable speed depends on range from target and how fast the AVR is moving P and D gains need to be tuned All control process is done through software Sum of error terms multiplied by the gains translate to voltage to drive the actuators (Error*Range) + (Error*Velocity) = Voltage

Testing  DC Motor/ H-bridge test  Range Finding Test  CMUcam2+ Pan and Tilt Test

Testing  DC Motor/H-Bridge turning wheels test  IR Detector/Reflector test  IR Detector/Reflector encoding wheel test  Chassis/Locomotion test with turning wheels  Locomotion test with IR detector/reflector

Testing  Locomotion test with ultrasonic sensor stationary target  Locomotion test with ultrasonic sensor moving target  Locomotion test with CMUcam2++ with stationary target  Locomotion test with CMUcam2++ with moving target  Locomotion test with all sensors

Budget Part NumberPart NameQty CostOrder DateSupplierManufacturer N/A Basic Breadboard 1 $11.956/30/09SparkFun LV-EZ2 Ultrasonic Range Finder Maxbotix LV- EZ2 1 $27.956/30/09SparkFunMaxbotix N/A Arduino Starter Kit 1 $49.956/30/09SparkFunArduino LTE-302,LTR- 301 Infrared Emitters and Detectors 1 $1.956/30/09SparkFun Lite-On Electronics SN H-Bridge 3 $12.007/21/09Acroname Texas Instruments R245- CMUCAM2+- Plus CMUcam2++ 1 $ /21/09Acroname FT232R USB to Serial kit 1 $29.007/21/09AcronameFTDI Chip n/aBattery/charger1$55.458/28/09Battery JunctionTenergy n/aRC servo2$259/3/09 Colonial Photo and Hobby n/a Total Cost$383.25

 Part allocation – 90%  Testing – 10%  Design – 95%  Construction/Prototyping – 20%  Total completed -50% Progress