Autonomous Tracking Robot Andy Duong Chris Gurley Nate Klein Wink Barnes Georgia Institute of Technology School of Electrical and Computer Engineering ECE4007, L04 April 24 th, 2009

2 Project Overview Autonomous tank with the ability to –Locate target –Track and follow target –Aim and fire projectile 1/16 scale proof-of-feasibility Save lives by removing humans from the front line of battle Development costs under $4,000

3 Vehicle Design

4 Design Objectives Locate a target: –Detect presence of target using IR sensors –Rotate to face target Track and follow: –Approach target to within 1.5m ±.25m –Correct course with color tracking software –Ultrasonic sensor to determine range Aim and fire projectile: –Aim turret using color tracking software –Fire projectile at target with a 6° cone of accuracy

5 Project Illustration: Target Acquisition

6 Project Illustration: Rotation and Approach

7 Hardware Overview

8 Hardware Design

9 Relay Circuit

10 Picture of Relay Circuits

11 Hardware: Sensors IR SensorIR Spot Sensor Movement Detection30cm Detection Distance (max)5m Horizontal Detection100°38° Vertical Detection82°22° Ultrasonic Sensor Detection Range0.1524m (6 inches) m (254 inches)

12 Hardware Pictures

13 Windows CE Embedded OS Software in C++ Phidgets 8/8/8 Board to read sensor inputs, send digital output signals “phidgets21” library for function calls –Analog methods return value between –IR sensor value >380 or <620 indicates target motion –IR Sensors steady state around 505 (~2.5V) –Spot sensor value >475 or <535 indicates aligned target Software Components

14 Software Algorithm Overview

15 Color Tracking Algorithm Edit webcam test software for color tracking algorithm Compare pixels and create groups of horizontal pixels of the target color (red) –A target is red if: R > G + B where R, G, and B are the red, green, and blue values in a pixel Compare neighboring horizontal pixel groups to form blobs Average the indexes of the largest blob and turn the tank based on the blob’s average offset from the center pixel

16 Problems Sensor/Webcam fluctuations reduce accuracy –Over 1m, moving target caused sporadic values –Webcam auto-corrects color, brightness, contrast Relative color tracking algorithm More power needed than expected –Digital outputs unable to provide sufficient current –USB does not provide enough power Spot sensor value hardcoded for specific location

17 Limitations Tracking target –Accumulation of error in turret rotation –Ground slippage –Vertical alignment not viable

18 Budget and Cost Analysis ItemQtyTotal Cost RC German Tiger Tank1$79 AMN23111 IR Motion Sensor4$144 AMN21111 IR Spot Sensor1$12 HB-401 H-Bridge1$50 Item (Borrowed)QtyEst. Cost QuickcamPro 9000 Webcam1$70 Phidgets Ultrasonic Sensor1$30 Wiring/Mounts/Transistors1$5 -Total Amount Spent: $285 -Total Estimated Parts Cost: $390 -Total Estimated Cost (1 Unit, Including Labor): $3260 -Total Proposed Selling Price (Based on Mass Production): $3600

19 Results GoalsProposedActual Detect TargetYES Approach Target Distance1.5m ±.25m 1.15m Relocate Target if LostYES Firing Accuracy 6°Cone5° Cone

20 Demonstration and Acceptance Testing Actions: 1. Detecting and rotating to face target 2. Approaching and tracking target 3. Aligning turret and firing projectile Testing StagesDescription One Independent testing of each action Two Testing of consecutive actions Three Testing of all actions consecutively

21 Future Improvements Suggested ImprovementBenefit Add encoder to turretHigher accuracy alignment to target Use multiple ultrasonic sensorsMore accurate distance readings Attain a higher quality cameraFewer false movements during color tracking Include push buttons to start/stop algorithm Provide more control when testing/demonstrating Hide hardware inside tankAesthetics; Less chance of wires interfering with tank mechanics

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