Sliding mode control design for discrete multivariable systems with time-delayed input signals

A discrete variable structure control method is developed for discrete multivariable systems. The switching functions are defined using the output and delayed signals. In the quasi-sliding mode, the closed-loop eigenvalues are proven to be within the unit circle in the z-plane. Therefore, the stability of this control system is guaranteed and the robust output performance is ensured in the quasi-sliding mode. In special cases, particular system transformations are carried out. Time-delayed input signals are applied. It is proven that the proposed control method assures robustness against system uncertainties and disturbances.