An autonomous sensor-based path-planner for planetary microrovers

With the success of Mars Pathflnder's Sojourner rover, a new era of planetary exploration has opened, with demand for highly capable mobile robots. These robots must be able to traverse long distances over rough, unknown terrain autonomously, under severe resource constraints. Based on the authors' flrsthand experience with the Mars Pathflnder mission, this pa- per reviews issues which are critical for successful au- tonomous navigation of planetary rovers. We next re- port on the \Wedgebug" algorithm for planetary rover navigation. This algorithm is complete, correct, re- quires minimal memory for storage of its world model, and uses only on-board sensors, which are guided by the algorithm to e-ciently sense only the data needed for motion planning. The implementation of a version of Wedgebug on the Rocky7 Mars Rover prototype at the Jet Propulsion Laboratory (JPL) is described, and experimental results from operation in simulated mar- tian terrain are presented.