Sliding Mode Control With Unmatched Disturbance and Implementation For a Three-Tanks System

The paper examines the problem of sliding mode manifold design for unmatched disturbance for nonlinear second order system (NSOS). Initially, nonlinear sliding mode control (NSMC) is applied with classical manifold (switching surface) [JJ.E Slotine et al "Sliding controller design for non-linear systems" International Journal of Control, 40, 1984, pp. 421-434.], and afterward, we designed a new sliding mode control based on dynamic sliding surface. The proposed method attenuates the effect of both unmatched uncertainties and external disturbances, moreover it eliminates the chattering phenomenon introduced by classical sliding-mode control. The application of this method to the three-tank system gives encouraging results which are presented and commented in this paper.