New Predictor-Based Anti-Disturbance Control for Discrete-Time Systems With Input Delay Subject to Time-Varying Uncertainties

In this article, a new predictor-based anti-disturbance control scheme is proposed for discrete-time systems with input delay subject to time-varying uncertainties, by only using the system output measurement. A high-order extended state observer is firstly constructed to simultaneously estimate the system state, unknown disturbance and its high-order difference with specification. Two alternative designs of the system state and disturbance predictors are then presented to construct an advanced anti-disturbance control scheme. The disturbance attenuation performance of the resulting closed-loop system is quantitatively analyzed. Moreover, a matrix-inequality-based sufficient condition is established to evaluate robust stability of the closed-loop system under time-varying uncertainties. Finally, a benchmark example is adopted to demonstrate the effectiveness and advantages of the proposed control schemes over the existing methods.