On extended state predictor observer based active disturbance rejection control for uncertain systems with sensor delay

This paper considers the control problem for a class of sensor delay systems with nonlinear unknown dynamics and external disturbances. The extended state predictor observer (ESPO) based active disturbance rejection control (ADRC) is first proposed to timely estimate and compensate for the "total disturbance" under sensor delay. The timedomain stability of the closed-loop system is rigorously studied by discussing the bound of tracking error between state and its desired trajectory. More importantly, it is proven that the proposed method can greatly improve the existing PO based control in dealing with the "total disturbance" in the low frequency range. Also, the simulation results show the effectiveness of the ESPO based ADRC for tackling several kinds of uncertainties.