Disturbance Observer Based Output Feedback Controller Design for Systems with Mismatched Disturbance

Abstract

For linear MIMO systems with mismatched unknown perturbations, this paper proposes a dynamic output feedback controller that uses a disturbance estimation algorithm. The proposed observer algorithm, which simultaneously estimates the system sates and the effect of an input disturbance, is successfully implemented in non-minimum phase systems. The developed control law, which uses estimation information into the controller design, can guarantee robust stabilization of the closed-loop system and sustain disturbance attenuation when the solutions to two algebraic Riccati inequalities are determined. Finally, the feasibility of the proposed method is illustrated using a numerical example.