Robust Tuning of Active Disturbance Rejection Controller for Time-Delay Systems With Application to a Factual Electrostatic Precipitator

Active disturbance rejection control (ADRC) shows great potential in mitigating various uncertainties of both motion and process control. However, the controller tuning is generally time-consuming, and the resulting performance highly depends on the individual experience. This brief aims to develop a standard robust tuning rule for a time-delayed ADRC structure based on a class of time-delay systems represented by a second-order plus time delay (SOPTD) model. The bandwidth parameters of the controller and the observer are, respectively, scaled in terms of SOPTD parameters. The resulting dimensionless parameters enable exhaustive evaluation of the robustness. Compared to the traditional metrics, it reveals that delay margin is the dominant robustness index for the controller tuning. A dominated form of the robust tuning rule is recommended, and the stability condition of a closed-loop system is given. Simulations and experiments are conducted on a factual electrostatic precipitator in the coal-fired power plant to validate the efficacy of the proposed tuning rule.