Obstacle Avoidance Path Planning for a 6-DOF Manipulator Based on Improved RRT Algorithm

Abstract

Taking the automatic handover process of parts in factory product assembly as the research object, the route of the manipulator to grasp the parts and place the parts is planned. In order to address the problems of strong path search randomness, low success rate and poor smoothness of generated trajectories in motion planning, an modified RRT algorithm is put forward for path planning combined with APF method, and a non-uniform four-order B-spline function is used for trajectory planning. Firstly, the RRT algorithm is improved, the probabilistic adaptive target bias strategy and the local minimum detachment mechanism are used to improve the planning efficiency, and then, the inhomogeneous four-degree B-spline function is applied for path smoothing, so as to realize trajectory optimization and ensure security, smooth and fast action of the robotic arm. The improved RRT algorithm aims to enable the robotic arm to successfully avoid barrier on the way to the target location while the motion trajectory of each joint has high-order continuity, and the time used for path planning running time of the robotic arm can be greatly shortened.