Motion planning and collision avoidance with complex geometry

CAD and robot simulation tools are often used to verify a workcell or process at the design phase: a geometric model of the machinery involved is produced, and pictures of the model examined for potential problems. However it is often very difficult to spot all possible problems by eye alone. Many systems provide some form of automated checking or automated path generation, but in our experience these are rarely used as they are either too slow or too limited. In order to address these problems we have developed a modular architecture called OXSIM for developing path planning programs. OXSIM explicitly separates out issues of geometric competence from planning competence, so that new ideas in path planning can be quickly tested without a programmer worrying about geometry, and conversely new types of geometry can be added to an existing path planner in a clean way. Most of the existing practical path planning methodologies can be written down in this way. Initial results from OXSIM have been encouraging, and we are now proceeding to tests on a large workcell.