Constrained Sampling-Based Planning for Grasping and Manipulation

This paper presents a novel constrained, sampling-based motion planning method for grasp and transport tasks with a redundant robotic manipulator. We utilize a planning margin for grasping with constraints that allow the best grasp configuration and approach direction to be determined automatically. For manipulators with many degrees of freedom, our method efficiently chooses the optimal grasp pose when there are many redundant solutions. The method also introduces a parameterized intermediate pose that is optimized to determine the approach direction, increasing robustness under sensor uncertainty and execution errors. Our method also considers transporting the grasped object to the desired target position using a Rapidly-exploring Random Tree (RRT) algorithm that incorporates soft constraints via appropriate cost penalties. We demonstrate the effectiveness and efficiency of our algorithms on a number of simulated and experimental applications. Our experimental results show a marked improvement in computational efficiency in comparison to previously studied approaches.