Predictive Active Disturbance Rejection Control for Servo Systems With Communication Delays Via Sliding Mode Approach

Abstract

In this article, a predictive active disturbance rejection control (ADRC) scheme is proposed for high-precision position tracking control of servo systems with communication delays via sliding mode approach. In the proposed framework, a filtered state predictor is employed to handle time delays in the networked control system. Based on the predictive states, a linear extended state observer is used to compensate unknown perturbations for ADRC, and a boundary layer solution of the sliding mode control is applied via the internal model control rules for robust control. Since the filtered predictive scheme can compensate the time delays and alleviate the effect of the ignored high-frequency dynamics, higher control gains and observer bandwidth of the ADRC can be achieved, leading to a better position tracking accuracy of the control system in the presence of uncertainties and disturbances. The stability of the overall control system is also analyzed via the Lyapunov method. Comparative experiments were carried out to validate the superior performance of the proposed controller.