Motion planning method for obstacle avoidance of 6-DOF manipulator based on improved A^* algorithm

The conventional A^* algorithm may suffer from the infinite loop and a large number of search data in the process of motion planning for manipulator. To solve the problem, an improved A^* algorithm is proposed in this paper by the means of selecting middle points and applying variable step segments searching during the searching process. In addition, a new method is proposed for collision detection in the workspace. In this paper, the MOTOMAN MH6 manipulator with 6-DOF is applied for motion plan. The algorithm is based on the basis of the simplification for the manipulator and obstacles by cylinder enveloping. Based on the analysis of collision detection, the free space can be achieved which makes it possible for the entire body to avoid collisions with obstacles. Compared with the Conventional A^*, the improved algorithm deals with less searching points and performs more efficiently. The simulation developed in VC++ with OpenGL and the actual system experiments prove effectiveness and feasibility of this improved method.