Adaptive sliding mode control for plants with mismatched perturbations to achieve asymptotical stability

In this paper an adaptive sliding mode control (ASMC) scheme based on the Lyapunov stability theorem is proposed for a class of multi-input multi-output (MIMO) systems with mismatched perturbations to solve robust tracking problems. Adaptive mechanisms are employed in the design of a specific sliding surface function, so that when the dynamics of controlled system enters the sliding surface, the adaptive gains are capable of adapting the upper bounds of mismatched perturbations and the trajectories of tracking errors can achieve the objective of asymptotical stability. Some adaptive mechanisms are also employed in the controller's design, so that the reaching phase can be accomplished in a finite time without the requirement of the information of upper bounds of partial mismatched perturbations. Finally the control scheme is applied to control an AC motor for showing the feasibility of the proposed methodology. Copyright (C) 2006 John Wiley & Sons, Ltd.