Practical Anti-windup for Open-Loop Stable Systems Under Magnitude and Rate Constraints: Application to Turbofan Engines

In this study, a practical anti-windup algorithm based on the state-space model (AWSS) is proposed to solve the performance deterioration problem for open-loop stable systems under actuator magnitude and rate constraints. To prevent undesirable windup behaviors caused by saturation, this study redesigns the integrator of the state-space equation through three steps: 1) init, 2) predict, and 3) correct. Unlike the previous algorithms, AWSS is not only applicable for controllers and observers expressed by state-space equations but also free from tuning parameters after designing the nominal part. In this way, $H_\infty$ controller and extended state observer are taken as examples to illustrate its superiority. Ultimately, the approaches are applied to a twin-rotor turbofan engine on hardware-in-the-loop platform. The comparative results from six cases demonstrate the significant improvement of AWSS.