Time Optimal Path-Tracking Control of Kinematically Redundant Manipulators

In this study, we propose a time optimal control scheme for kinematically redundant manipulators to track a predefined geometric path, subject to joint torque limits. The scheme can make full use of redundancy to increase the path-tracking velocity, and the time optimal trajectory planning problem is solved by using the phase-plane analysis and the linear programming technique. Computer simulation is also executed on a three-link planar rotary manipulator to show that, 1) the redundancy of the manipulator is fully used to increase the path-tracking velocity, and 2) redundant joints plus one more joint use their bound values of torque all the time while the time optimal path-tracking task is performed.