Observer-based deadband control for discrete systems subject to external disturbance

This paper is concerned with designing the observer-based deadband output feedback controller for discrete-time systems subject to unknown but bounded external disturbance. Specifically, an augmentation method is utilized to estimate the system states and the disturbance, followed by designing the controller with the estimated states and disturbance. Moreover, a predefined updating instants scheduler is introduced to update the observer-based deadband controller thus designed. A theoretical analysis is provided for the stability and disturbance rejection properties of the resulting closed-loop system. A simulation example is presented to show the good performance of the designed observer-based deadband controller in terms of reduced frequency of updating the controller and disturbance rejection.