Nonlinear sampled-data ESO-based active disturbance rejection control for networked control systems with actuator saturation

This paper proposes a framework of anti-windup active disturbance rejection control for the networked control systems (NCSs) subjected to actuator saturation. The sensor-to-controller network is considered where only one sensor can report its measurements at each transmission instant. Both the round-robin and try-once-discard protocols are applied, respectively, to determine which sensor should be given the access to the network at a certain instant. To reflect the impact of communication constraints, a nonlinear sampled-data extended state observer (NSESO) is employed to estimate the states and ignored nonlinearities of the addressed system. Then, a composite control strategy with an anti-windup compensator is designed based on the NSESO, and the effects of actuator saturation is eliminated by the anti-windup compensator. The sufficient conditions to guarantee the convergence of the NSESO are provided, and then the input-to-state stability of the overall NCSs is given as well. Finally, a numerical example is introduced to demonstrate the effectiveness of the proposed design technique.