Collision free motion planning for two robots operating in a common workspace

This paper presents a collision free motion planning method for two robots operating in a common three dimensional workspace. Initial time-optimal trajectories are constructed without attention to potential collision. These trajectories are then used to construct a collision map highlighting areas of collision. The collision map uses joint velocity to determine the optimum sampling frequency which makes the collision detection process computationally efficient and suitable for real-time implementation. Collision free trajectories are obtained either by time scheduling or alternatively, utilising a simple search technique to derive a new collision free path and then deriving a minimum time trajectory for this path. An example is shown which shows the significance of the approach and implementation issues are discussed.