DISTURBANCE ESTIMATOR-BASED CONTROL FOR MANIPULATORS WITH MODEL UNCERTAINTY AND DISTURBANCE

Abstract

Robotic manipulators have been widely applied in practice. They operate in different environments and can take time-varying loads. Thus, their mathematical models can be uncertain and will be affected by external disturbances. In this paper, a disturbance estimator-based feedback linearization controller is proposed for a robotic manipulator with model uncertainty and unknown disturbance. First, a mathematical model with model uncertainty and unknown disturbance is obtained for the robotic manipulators. Then, based on this model, the disturbance estimator and proposed controller are designed. Next, stability analysis is rigorously performed, and the tracking error is proved to be bounded. The proposed controller improves the control performance of the feedback linearization controller when there exists model uncertainty and disturbance. Numerical simulations for a two-link planar robot are carried out to verify the proposed regulator and to compare with the existing one. Results show that the control quality is better than that of the feedback linearization controller.