Discrete‐time variable structure control for robust tracking and model following

This paper presents a discrete‐time variable structure controller for a class of uncertain linear systems to track dynamic outputs of a non‐delay reference model. The selection of switching surface and the existence of sliding mode are two important issues, which have been addressed. It is shown that the proposed approach guarantees closed‐loop system stability and asymptotically achieves zero‐tracking error in the presence of parameter uncertainties and external disturbances. Also, this scheme assures robustness against system uncertainties and disturbances, and the chattering phenomenon is eliminated. Finally, simulation results demonstrate the efficacy of the proposed control methodology.