Tracking control of a manipulator under uncertainty by FUZZY P+ID controller

One of the most important manipulator operations is the control of the manipulator to track a given trajectory. Most commercial robot systems currently are equipped with conventional PID controllers due to their simplicity in structure and ease of design. Using PID control, however, it is di=cult to achieve a desired tracking control performance since the dynamic equations of a mechanical manipulator are tightly coupled, highly nonlinear and uncertain. In order to improve the tracking control performance under uncertainty, this paper presents a new hybrid control scheme for the manipulator, which consists of a fuzzy logic proportional controller and a conventional integral and derivative controller (FUZZY P+ID). In comparison with a conventional PID controller, only one additional parameter has to be adjusted to tune the FUZZY P+ID controller. The proposed control scheme has been implemented on a direct drive two-link manipulator. The outlined experimental results on tracking control under inertial parameters’ changes demonstrate the eAectiveness and the robustness of the new FUZZY P+ID controller. c 2001 Elsevier Science B.V. All rights reserved.