Real-Time Trajectory Generation for Redundant Manipulators with Path Constraints

This paper addresses the problem of tracking a prescribed geometric path by the end effector of a kinematically redundant manipulator at the control loop level. The constraints imposed on the robot actuator controls are taken into account. The Lyapunov stability theory and/or the calculus of variations is used to derive the control scheme. Through the use of an exterior penalty function approach, an additional objective to be fulfilled by the robot, that is, collision avoidance of the manipulator links with obstacles, is ensured. The extensive computer simulation results illustrate the trajectory performance of the proposed control scheme for a geometric end effector path given in both an obstacle-free work space and a work space including obstacles. KEY WORDS—redundant manipulator, end-effector path, stability, collision avoidance