Adaptive Variable Structure Control for Mismatched Uncertain Systems

Abstract

This paper proposes an adaptive variable structure control (VSC) for a class of mismatched uncertain systems with unknown disturbances. First, a necessary and sufficient condition in terms of linear matrix inequalities is proposed to guarantee the system in sliding mode is asymptotically stable. Second, an adaptive output feedback variable structure controller is designed to force the system states reach the sliding surface and stay on it thereafter. Finally, the advantages and effectiveness of the proposed approaches are demonstrated via a numerical example.