Anti-windup compensation of saturated systems with phase-lead/phase-lag controller

In this paper, the phase-lead/phase-lag controller is selected as the main controller to achieve desired performance. Based on the observer-based scheme, an auxiliary compensator of the main controller is designed to improve the performance reduction due to actuator saturation. To obtain the auxiliary controller, the effect of actuator saturation is modeled as a disturbance imported to the main controller and an auxiliary compensator is derived by solving an H_∞ optimization problem. It is shown that the resulting auxiliary controller is only associated with the parameters of the main controller. Therefore, it can be easily implemented to the practical applications.