System Identification and $H_{\infty}$ Robust Control of Voice Coil Actuator Fast Steering Mirror

The mechanical alignment error of the voice coil motor and its internal flexible support structure can influence the modeling accuracy and limit the improvement of the control system's tracking bandwidth. To address the above-mentioned issues: firstly, the nominal model of voice coil actuator-fast steering mirror (VCA-FSM) is obtained by frequency response identification method, and the model quality is evaluated by gap metrics; secondly, an
$H_{\infty}$
controller is designed, and its tracking and disturbance rejection capabilities are experimentally validated. The experimental results demonstrate that the closed-loop bandwidth of the system reaches 128.02Hz, and the disturbance rejection bandwidth is 70Hz under the action of the
$H_{\infty}$
controller, showing an improvement of 137.03% and 133.33%, respectively compared to the PID control system.