快速反射镜（Fast Steering Mirror，FSM）是高精密光学系统中的关键仪器，基于音圈电机（Voice Coil Actuator，VCA）驱动的柔性支撑FSM存在复杂耦合特性，导致系统模型复杂并严重影响系统的控制性能，对于该问题，本文提出了一种基于系统辨识与模型降阶的双轴积分增广滑模控制方法。首先，采用基于脉冲响应的Hankel矩阵系统辨识方法建立VCA-FSM的精确耦合模型；随后，基于平衡实现与平衡截断，在保证模型精度的前提下对所建立的高阶模型进行降阶；其次，基于降阶模型，采用现代控制理论方法设计积分增广滑模控制器，通过设计状态观测器构造滑模切换函数与控制律，并在控制设计中改进符号函数以消除滑模抖振；最后，基于VCA-FSM伺服控制系统实验平台，开展频域与时域性能测试实验。实验结果表明：本文所提控制方法相较于单轴滑模、PID控制方法，系统的闭环跟踪带宽分别提高了约50.3%，251.3%，扰动抑制带宽分别提高了约39.9%，451.9%，阶跃响应调节时间分别缩短了约29.7%，97.7%，螺旋线跟踪精度分别提高了约48.5%，97.8%，且实现了对存在强耦合特性VCA-FSM的解耦控制。本文所提控制方法充分提高了VCA-FSM的控制性能。

A fast-steering mirror （FSM） is a key instrument in high-precision optical systems. However， the flexible-support FSM driven by a voice coil actuator （VCA） possesses complex coupling characteristics； this leads to a complex system model and severely impacts the control performance. To address this issue， this study proposes a dual-axis integral augmented sliding-mode control method， based on system identification and model reduction. Firstly， an accurate coupled VCA-FSM model is established using the Hankel-matrix system-identification method based on pulse response. Subsequently， based on balanced realization and truncation， the high-order model is reduced， while ensuring model accuracy. Next， an integral augmented sliding-mode controller is designed， adopting a modern control-theory method and using the reduced-order model. A state observer is constructed to create the sliding-mode switching function and control law， and the sign function is improved in the control design to eliminate sliding-mode chattering. Finally， frequency-domain and time-domain performance-testing experiments are conducted on the VCA-FSM servo control-system experimental platform. The experimental results demonstrate that the proposed control method significantly improves the control performance of the VCA-FSM servo system， compared to the single-axis sliding-mode and PID control methods. The closed-loop tracking bandwidth is increased by approximately 50.3% and 251.3%， respectively， the disturbance-suppression bandwidth is increased by approximately 39.9% and 451.9%， respectively， the settling time of the step response is reduced by approximately 29.7% and 97.7%， respectively， and the tracking accuracy of the spiral line is improved by approximately 48.5% and 97.8%， respectively. Moreover， the proposed control method controls the decoupling of the VCA-FSM with strong coupling characteristics. The control method proposed in this study greatly improves the control performance of the VCA-FSM.