High-precision inverse kinematics based on discrete workspace for obstacle avoidance

As redundant manipulator, 3-link planar manipulator can achieve optimization objective by the extra degree. An efficient approach of inverse kinematics for obstacle avoidance via discrete workspace is proposed. This paper concentrates on optimizing one of three joints to track the path of EEF (end effector). First of all, ensure feasible region of workspace through taking advantage of geometrical features and divide the workspace by discrete cell as search space. Secondly, in order to compromise computation complexity and efficiency of avoiding obstacles, artificial forbidden zone around obstacles in space and motion zone that cover virtual obstacles on the ground are proposed. Furthermore, two-phase computation is used to resolve joint angles by analytical solution for achieving high-precision. At last, a simulation of inverse kinematics based on discrete workspace for 3-link planar manipulator to track a path is presented, the results demonstrate the efficiency of obstacle avoidance and high-precision inverse kinematics algorithm with low computation burden.