TERRAIN MAPPING FOR A WALKING PLANETARY ROVER

We present a terrain mapping system for walking robots that constructs quantitative models of surface geometry. The accuracy of the constructed maps enables safe, power-efficient locomotion over the natural, rugged terrain found on planetary surfaces. The mapping system acquires range images with a laser rangefinder, preprocesses and stores the images, and constructs elevation maps from them at arbitrary resolutions, in arbitrary reference frames. To quantify performance in terms of accuracy, timing, and memory utilization, we conducted extensive tests in natural, rugged terrain, producing hundreds of millions of map points. The results indicate that the mapping system 1) is one of the few that can handle extremely rugged terrain, and 2) exhibits a high degree of real-world robustness due to its aggressive detection of image-based errors and in its compensation for time-varying errors.