A Practical Redundancy Resolution for 7 DOF Redundant Manipulators with Joint Limits

This paper proposes a practical redundancy resolution for 7 DOF redundant manipulators with joint limits. The primary concern of the paper is how to resolve the redundancy in the global configuration space when the movable joint angles are considerably restricted. First, a parameterized inverse kinematic solution for a 7 DOF manipulator model is derived. Second, how the joint limits affect the inverse kinematic solution is examined to explicitly identify the feasible solution under the joint limits. Then, an analytical redundancy resolution method for avoiding the joint limits is developed. Finally, kinematic simulations show that the method is effective for avoiding the joint limits as well as expanding the reachable region of the manipulator's tip.