Motion planning with many degrees of freedom-random reflections at C-space obstacles

This paper describes a motion planner that automatically avoids collisions with obstacles. A transformation of obstacles into configuration space (C-space) is not necessary. Given a polyhedral description of robot, load and environment the algorithm first computes (off-line) a graph which roughly represents the skeleton of the freespace. Due to the way of its computation this graph does not preserve connectivity, although the freespace is a connected set, which is assumed throughout this paper. Reflecting randomly at C-space obstacles a connection between subgraphs is generated. In a second step (online) a connection between a start and a goal configuration to the graph is searched for. The impact of this algorithm concerning movable obstacles is discussed. This method is general and four examples are presented to demonstrate its feasibility by applying it to different kinematic structures with 3, 6 and 12 degrees of freedom