Vision-based sensing and control for space robotics applications

The following problems arise in the precise positioning of payloads by large space manipulators: The precise measurement of the relative motion between objects; and the design of a control system which is robust and performs well in spite of the effects of structural flexibility and oscillations. This paper describes the solution to the measurement problem by using a video camera as sensor and photogrammatic image processing to determine relative position, orientation and velocity between objects. The control problem is addressed by a new technique dealing effectively with the problem of controlling flexible structures with partially non-collocated sensors and actuators. The implementation of the measurement and control technique in a laboratory environment is discussed. Preliminary results validate the concept