Robust model-following control for a robot manipulator

A robust model-following control scheme for a rigid-body robot manipulator, is proposed. Given a nominal model of the manipulator, the manipulator dynamics are approximately linearised by nonlinear compensation based on the nominal model. Then the dynamics of tracking error between the state vectors of the linearised manipulator and a reference model are described as a descriptor-form equation. A state feedback controller is designed for the descriptor-form equation so as to guarantee robust stability and robust performance of the closed-loop system in the 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 manipulator show the effectiveness and robustness of the proposed controller.