Qualitative representation of outdoor environment along route

This paper proposes an idea of representing qualitatively a route in an outdoor environment in terms of landmarks. A robot continuously scans the side-view and yields an intermediate representation called panoramic representation. The objects in the scene are segmented based upon range and color information in the panoramic representation, and they are then arranged into a structure map which provides qualitative information on the environment structure. The objects which have distinctive features along the route are selected as the landmarks. Since their relative spatial management is invariant with the camera speed, the memorized landmark can be matched with the objects in the new structure map by a dynamic programming-based method. The correctness of matching is further verified by using the disparity and color cues. Results of experiments in, a real outdoor world show the effectiveness and and robustness of this method