Path Re-Planning Design of a Cobot in a Dynamic Environment Based on Current Obstacle Configuration

Abstract

This study proposes a path planning algorithm to generate a collision-free path that avoids static and dynamic obstacles in real time. An efficient path re-planning method is presented for obstacle avoidance for a cobot in an environment that is shared by humans and robot. Static and dynamic obstacles are tracked when the manipulator executes a trajectory along a planned initial static path. When a dynamic obstacle enters the robot's workspace, the proposed method re-plans a collision-free local path to avoid static and dynamic obstacles. To allow fast local re-planning, a hybrid method that combines the advantages of APF and RRT path planning algorithm is proposed. The weight factors for the hybrid method is determined according to the current configuration of obstacles. The experimental results for a TM5-700 manipulator show that the proposed method decreases re-planning time and path length in an environment with static and dynamic obstacles. The path re-planning time is at least 55% less than those for two existent path planning optimization methods D-RRT and VF-RRT.