ROBUST MODEL-FOLLOWING CONTROL FOR A ROBOT MANIPULATOR

A robust model-following control scheme for a rigid-body robot manipul ator, is proposed. Given a nominal model of the manipulator, the manip ulator dynamics are approximately linearised by nonlinear compensation based on the nominal model. Then the dynamics of tracking error betwe en the state vectors of the linearised manipulator and a reference mod el are described as a descriptor-form equation. A state feedback contr oller is designed for the descriptor-form equation so as to guarantee robust stability and robust performance of the closed-loop system in t he presence of uncertain nonlinear perturbations. The proposed control scheme is applied to a two-link direct-drive manipulator. Results of experiments carried out to evaluate tracking performance of the manipu lator show the effectiveness and robustness of the proposed controller .