An autonomous path planner implemented on the Rocky 7 prototype microrover

Much prior work in mobile robot path planning has been based on assumptions that are unrealistic for exploration of planetary terrains. Based on the first author's experience with the Mars Pathfinder mission, this paper reviews issues that are critical for successful autonomous navigation of planetary rovers. No currently proposed methodology accurately addresses all of these issues. We report on an extension of the recently proposed "TangentBug" algorithm. The implementation of this extended algorithm on the Rocky 7 Mars Rover prototype at the Jet Propulsion Laboratory is described and experimental results are presented. In addition, limitations encountered by the Sojourner rover in actual Martian terrain suggest that terrain traversability is a key issue for future interplanetary rover autonomous planning algorithms.