Estimation of the absolute position of mobile systems by an optoelectronic processor

A method that determines the absolute position of a mobile system with a hybrid optoelectronic processor has been developed. Position estimates are based on an analysis of circular landmarks that are detected by a TV camera attached to the mobile system. The difference between the known shape of the landmark and its image provides the information needed to determine the absolute position of the mobile system. For robust operation, the parameters of the landmark image are extracted at high speeds using an optical processor that performs an optical Hough transform. The coordinates of the mobile system are computed from these parameters in a digital coprocessor using fast algorithms. Different sources of position estimation errors have also been analyzed, and consequent algorithms for improving the navigation performance of the mobile system have been developed and evaluated by both computer simulation and experiments