Tutorial review on repetitive control with anti-windup mechanisms

In many control system applications, tracking a periodic reference signal or rejecting a disturbance signal with a limited frequency band is a necessary task. Repetitive control systems are designed to perform such tasks. Because the repetitive control systems by nature have introduced unstable controller structures, control signal amplitude constraints commonly encountered in control system applications need to be considered with special care. Otherwise, the repetitive control system could become unstable when the control signals became saturated. Using the same framework of Model Predictive Control (MPC), but without the cost of online optimization that usually occurs in the MPC algorithms, this paper shows the design and implementation procedures of repetitive control of multi-input and multi-output systems with anti-windup mechanisms. Furthermore, by using Fourier analysis of a reference signal or a disturbance signal, the structure of a repetitive control system is determined. Simple and complex simulation examples are used to illustrate the procedures of design and implementation.