Positive hysteresis model-based feedforward control for rate-dependent hysteresis suppression in fast steering mirrors

This study introduces an innovative feedforward compensation method (PF) based on a positive hysteresis model to suppress the rate-dependent hysteresis phenomenon of fast steering mirrors (FSMs). In this approach, the rate-dependent hysteresis characteristic of the FSM is considered as an inherent disturbance in the system, and a positive hysteresis model is used to estimate this disturbance. By applying the disturbance estimated in advance, the input signal excited to the system is designed to realize the feedforward control of the FSM. Compared to the traditional feedforward compensation method with the inverse hysteresis model (IF), PF directly utilizes the positive hysteresis model to compensate for the hysteresis effect of the system. On the one hand, the solution process of the inverse model is avoided, which greatly simplifies the hysteresis compensation work. On the other hand, the computational complexity of PF is the same as that of IF and its maximum computation time remains on the order of microseconds, which is suitable for real-time applications. Furthermore, the PF is combined with a proportional-integral feedback controller (PI) to construct compound control. The experimental results demonstrate the effectiveness of the presented method.