Planning collision-free and occlusion-free paths for industrial manipulators with eye-to-hand configuration

This paper presents a motion planning algorithm for industrial manipulators with the simultaneous constraints of avoiding collisions and avoiding the occlusion of specified pixellated regions of an eye-to-hand camera. The system uses a probabilistic roadmap to satisfy the constraints imposed by the command interface of typical industrial manipulators and uses dynamic collision checking to ensure collision-free motion. In the context of a task monitored by a camera, we enhance a probabilistic roadmap with a dynamic occlusion checking algorithm that is able to determine which pixels of the camera are occluded by the robot during each motion segment. The occlusion algorithm is formulated as collision algorithm where the field of view of the camera is represented as a quadtree of frustums. The proposed algorithm is demonstrated in industrial bin picking simulations where the gripper must not occlude the targeted object throughout the task.