Observer Based Variable Structure Controller Design for Robust Tracking and Model Following

Abstract

For a linear system with matched uncertainties, a variable structure model following controller using output feedback is developed in this paper. Although the system contains an uncertain term, a novel reduced-order observer proposed in this work can effectively estimate the system states. Based on the estimated states and the observer model, although the system exists matched uncertainties, the proposed controller can satisfy the reaching and sliding condition after some finite time. Moreover, when the system is in sliding mode, it can be shown theoretically that the tracking error decreases asymptotically to zero. Finally, a numerical example is given to demonstrate the feasibility of the proposed scheme.