Output feedback sliding mode controller with improved tracking performance

Abstract

This paper considers the trajectory tracking problem for nonlinear second order systems in case of unmeasured system states and bounded external disturbances. A combination of sliding mode controller and observer scheme is used. A time varying sliding surface based on system state estimates is defined and the angle information instead of the slope value is used in order to improve the trajectory tracking performance of the system. Computer simulations are presented to show the effect of the time varying sliding surface on the performance of the output feedback sliding mode controller. It is shown that the trajectory tracking performance is improved while the robustness of the system is conserved with respect to the output feedback sliding mode controller with a constant sliding surface parameter.