Adaptive quasi-sliding-mode control for discrete MIMO systems

In this paper, a discrete robust adaptive quasi-sliding mode tracking controller is presented for the multi-input multi-output (MIMO) systems with unknown parameters, unmodeled dynamics and bounded disturbances. The adaptive algorithm to estimate the parameters (including the parameters in the interactor matrix) is formulated even though the upper and lower bounds of the disturbances are unknown. The robust tracking controller is comprised of adaptive control and a sliding mode based control design. The bounded motion of the system around the sliding surface and the stability of the global system in the sense that all signals remain bounded are guaranteed.