1. Vision Tracking System
Presented By
Timothy Bagnull
James Deloge
Chad Helm
Matthew Sked
ECSE 4962 – Control Systems Design
Rensselaer Polytechnic Institute
4/22/03
Introduce team etc.

2. Overview Objective and Specifications System Design
Testing and Verification
Problems Encountered
System Demonstration
Conclusions
State topics to be covered

3. System CAD Model

4. Objective and Specifications
Track a moving point with a camera and pan-tilt system.
Controller Specifications
Maximum target speed: 1 ft/s
Settling time: 0.1 s
Overshoot: 2 %
Vision Specifications
Initialize system using an edge detection algorithm
Track target using a Kalman Filter
Re-cap design objective

5. System Design: Controller
Linear Controller
Effects of Coulomb Friction
Real Time System Response
Motor Saturation

6. System Design: Controller Linear Controller - Pan

7. System Design: Controller Linear Controller - Tilt

8. Effects of Coulomb Friction

9. Effects of Coulomb Friction

10. System Design: Controller Real Time System Response - Pan

11. System Design: Controller Real Time System Response - Tilt

12. System Design: Controller Motor Saturation - Pan

13. System Design: Controller Motor Saturation - Tilt

14. System Design: Vision Implemented using C++
4 levels of communication
Camera – Frame Grabber – Computer - ARCS
Find the target: Roberts Edge Detector
Track the target: Incremental Step Function
Future Modification: Kalman Filter, Pattern Recognition

15. System Design: Vision Roberts Edge Detector
Calculates the first order image gradient magnitude
Through a threshold function we determine which pixels are line pixels and which are not
By assuming an ideal environment we can calculate the center of the point by taking the mean of our line pixels

16. System Design: Vision Normal Lighting Conditions
Original Screen Grab | Edge Detection Output

17. System Design: Vision Poor Lighting Conditions
Original Screen Grab | Edge Detection Output

18. Original Screen Grab | Edge Detection Output
System Design: Vision
Focus Conditions
Original Screen Grab | Edge Detection Output

19. System Design:Vision -,- +,- +,+ -,+ Incremental Step Function
Determines target position in coordinate frame
Steps towards target using increment function
(0,0)
(640,0)
-,-
+,-
(320,240)
+,+
-,+
(480,0)
(640,480)

20. Testing and Verification
Controller
Trajectory program
Line,Circle, Jog Functions
Vision
Edge Detection
Incremental Step Function
System

21. Problems Encountered
Real time system controller tuning vs. simulated controller tuning
Coordinate transformations between vision and ARCS systems
Learning programming interfaces between mechanical and visual systems

22. Final System Performance
Final Performance
Maximum tracking speed: 0.5 ft/s
Settling time: 1 s
Overshoot: 50%
Initial Specifications
Maximum target speed: 1 ft/s
Settling time: 0.1 s
Overshoot: 2 %

23. Open Loop Response Pan: Torque at 0.1 Nm

24. Open Loop Response Tilt: Torque at 0.09Nm

25. Conclusion
We successfully implemented a vision system with a mechanical pan/tilt
Future work can be done to make this system much more robust
Overall we have shown that vision can be a used as an effective sensor in controls

26. Demonstration Independent joint test System test
Track horizontally moving target
Track vertically moving target
System test
Random Motion
Tracking performance test

28. Questions?