Efficient Sensor/Model Based On-Line Collision Detection for Planetary Manipulators

Safeguarding is a crucial need for manipulator operations on planetary rovers. At the same time, the computing environment on a Mars rover is extremely limited, which necessitates a highly efficient collision checking algorithm. We present such an algorithm that uses the Oriented Bounding Box (OBB) and a new primitive called the Oriented Bounding Prism (OBP) to detect potential selfcollisions and collisions with terrain object sensed with the rover’s on-board stereo camera; the algorithm thus has both model-based and sensor-based components. We have implemented the algorithm on JPL ’s FIDO rover and have tested it under realistic j e l d conditions. Performance analysis indicate this method is significantly faster than previously reported results in the literature, in addition to incorporating sensed geometry. The method is being considered for implementation on the MER rovers, which will land on Mars after launch in 2003.