Exact Collision Checking of Robot Paths

This paper describes a new exact and efficient collision checker for testing single straight-line segments in c-space or sequences of such segments. This checker is particularly suited for probabilistic roadmap (PRM) planners applied to manipulator arms and multi-robot systems. Unlike the commonly used fixed-resolution method, the new checker does not require manual tuning of the resolution parameter and cannot fail to find existing collisions. To achieve this, it automatically and dynamically adjusts the required local c-space resolution by relating distances and path lengths in workspace. Several additional techniques are presented in this paper to further increase the checker’s efficiency in PRM planners and scenarios with high geometric complexity. Extensive experiments, first on segments randomly generated in c-space, next as part of an existing PRM planner, and finally as part of a path smoother/optimizer have shown that the new checker is faster than the common resolution-based approach (with suitable resolution).