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.

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

System CAD Model

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

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

System Design: Controller Linear Controller - Pan

System Design: Controller Linear Controller - Tilt

Effects of Coulomb Friction

Effects of Coulomb Friction

System Design: Controller Real Time System Response - Pan

System Design: Controller Real Time System Response - Tilt

System Design: Controller Motor Saturation - Pan

System Design: Controller Motor Saturation - Tilt

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

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

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

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

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

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)

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

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

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 %

Open Loop Response Pan: Torque at 0.1 Nm

Open Loop Response Tilt: Torque at 0.09Nm

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

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

Questions?