Robust and accurate time-optimal path-tracking control for robot manipulators

Abstract

The well-known algorithms for time-optimal trajectory planning are difficult to apply in practice because they rely on imperfect models of the robot dynamics, they take no account of controller dynamics, and they provide no connection to tracking accuracy. In this paper we propose two schemes for planning and implementing time-optimal control to enable robots under computed torque control to track paths to a prescribed tolerance. Experimental results confirm the theories, showing that both schemes track to a prescribed accuracy in a near time-optimal fashion. The second scheme is shown to perform better, achieving complete torque utilization nearly all of the time.