Robust Sliding-Mode Control with Disturbance Attenuation Using Only Output Feedback

For a linear system with mismatched disturbance, a robust sliding mode control, using output feedback only, is developed in this paper. Although the system has an uncertain term, a novel state estimator is used which, using only measured outputs, can asymptotically estimate the system states. A control law is then designed with respect to the estimated signals. In addition, based on the H_∞ theory, the designed sliding surface can achieve robust stabilization and guarantee disturbance attenuation during sliding mode. Finally, a numerical example is demonstrated for showing the applicability of the proposed scheme.