PD-Type Two-Stage Robust Tracking Control for Robot Manipulators

Abstract

In this paper, we propose a practical design method of a Fixed-Gain-Type controller (PD-controller) for manipulators. The controller has the following properties;(a) The desired trajectory can be specified.(b) The control accuracy can be specified.(c) The convergence characteristics of initial error can be specified.(d) The robustness to modeling errors and to measurement noises is ensured.(e) The structure of the controller is simple.The main idea of our method is that we take account of the work space of a practical manipulator precisely and adopt the Two-Stage Robust Tracking Control System (Two-Stage-RTCS) developed by the authors. The consideration of the work space is used for assuring the boundedness of state variable of the manipulator and the Two-Stage-RTCS is used for avoiding an excessive input torque to the manipulator. Further, we show that the controller based on the Computed-Torque-Method can be used as a robust controller.