A vision based correlator to actively damp vibrations of a coarse-fine manipulator

A novel method for controlling the endpoint position of a coarse-fine manipulator using a fast vision sensor is presented. With the vibrational disturbances caused by both the manipulator and its environment can be attenuated for disturbance frequencies up to 8 Hz using active feedback control. At the same time, the bandwidth of the control response extends to 30 Hz. By visually sampling the workpiece surface within the operating range of the fine manipulator, a relative displacement in x and y can be estimated by correlating successive image frames. Because of the high computational complexity and the speed requirements, a dedicated correlation processor based on three digital signal processors has been developed for each axis. Results of simulations and experiments with the correlation processor are presented