为了进一步抑制装配误差扰动对快速反射镜控制系统输出性能的影响，提升系统的跟踪精度，基于干扰观测原理，提出了一种具有内、外双干扰观测环节的扰动抑制方法。分析了快速反射镜组件装配误差对控制系统精度的影响，建立了不平衡力矩扰动的等效数学模型；利用内环干扰观测环节实现对中高频扰动的抑制，应用外环干扰观测环节补偿内环干扰观测环节的中低频扰动放大作用并提供中低频扰动抑制；分析了提出方法的输入和误差信号传递过程，设计了扰动抑制系统各控制器的控制参数；搭建了虚拟样机仿真测试平台，对控制系统的性能进行了测试。结果显示，加入双干扰观测环节前后，虚拟样机系统的调节时间误差为0.54%，对于15 Hz等效扰动，扰动抑制能力提升了25.23%。理论和实验结果表明，双干扰观测环节的引入可以有效抑制装配误差的扰动。

To further suppress the effects of assembly error disturbance on the output performance of a fast steering mirror control system and to improve the tracking accuracy of the system, a disturbance suppression method with internal and external disturbance observation links based on the principle of disturbance observation is proposed. The effects of the assembly error of the fast steering mirror on the accuracy of the control system were analyzed, and an equivalent mathematical model of the unbalance torque disturbance was developed. The inner loop interference observation link was used to suppress medium- and high-frequency disturbances, whereas the outer loop interference observation link was used to compensate for the medium- and low-frequency disturbance amplification of the inner loop interference observation link and provide medium- and low-frequency disturbance suppression. The input and error signal transmission process of the proposed disturbance suppression method were analyzed, and the control parameters of each controller of the suppression system were designed. A virtual prototype simulation test platform was built to test the performance of the control system. The results show that the adjustment time error of the virtual prototype system is 0.54% before and after the double interference observation link is added. For a 15-Hz equivalent disturbance, the disturbance suppression capability is improved by 25.23%. Theoretical and experimental results show that the introduction of a double disturbance observation links can effectively suppress the disturbance of the assembly error.