Robust Discrete-Time Model Reference Sliding-Mode Controller Design With State and Disturbance Estimation

In response to a multi-input-multi-output discrete-time linear system with mismatched disturbance, an algorithm that is capable of performing estimated system state and disturbance is first proposed, followed by the design of the controller. Provided that the variation of disturbance in the two consecutive sampling instances is not significantly changed, both the system state and the disturbance can simultaneously be estimated by our proposed observer algorithm, with the estimation error being constrained in a small bounded region. Then, a method that utilizes a command generator tracker is designed to generate the reference model. The estimations of the system state and disturbance are then used in the sliding-mode controller, causing the tracking error to be constrained in a small bounded region with the guaranteed system stability. Finally, a numerical example is presented to demonstrate the applicability of the proposed control scheme.