Sliding Mode Control Algorithm Design for a Class of Unmatched Uncertain System

An Integral sliding mode control algorithm for a class of unmatched uncertain system is proposed in this paper. In order to make that the perturbation is minimal, the perturbation is provided into two parts by projection matrix--the matched and unmatched perturbation. It is also shown that when the minimum is attained and the resulting perturbation is not amplified. The controller design uses integral sliding mode concept and optimal control to ensure finite-time convergent in the effect of the unmatched uncertainty. The time convergence is chosen in advance. Simulation studies demonstrate that the proposed controller is robust with respect to the perturbation. An illustrative example of an aircraft control shows the applicability of the method.