Testing a stereo vision system for motion compensation

An experiment to demonstrate a stereo vision tracking system is described. A PUMA 560 six degree-of-freedom manipulator was required to follow a moving target in 2D space. A stereo vision system was developed to track a target as it moved, relative to the cameras and thus relative to the manipulator shoulder. The spatial data gathered by the vision system was then used to modify the path of the manipulator such that the manipulator end flange remained fixed relative to the target. An inertial system comprising an extensible `finger´ connecting the manipulator to the target was used to measure errors between the desired (target) trajectory and the actual (manipulator) trajectory. This paper discusses the requirements for such a tracking system, the means of its testing and the results obtained