为了保证快速反射镜控制系统在时域和频域同时具有良好性能, 采用了一种改进根轨迹的控制参量设计方法。首先, 根据辨识出的模型, 建立音圈电机驱动的快速反射镜传递函数的根轨迹; 其次, 根据对控制系统性能指标的要求, 导出闭环控制系统预期主导极点位置; 再次, 通过配置控制器的零点位置, 使系统的根轨迹具有预期的主导极点; 最后, 根据模值公式和相角公式, 确定系统增益和控制器极点位置。结果表明, 采用改进根轨迹法设计的控制系统具有良好的动态性能, 还可以有效抑制闭环系统的机械谐振, 而且简单易行、通用性强。

In order to obtain good time and frequency domain quality of a fast steering mirror (FSM), a method based on improving root locus was used to design its control parameters. At first, the root locus of FSM driven by a voice coil motor was established according to the identificated dynamic model. Then the expected dominant pole position was calculated based on the performance specification of the control system. By configuring the zero position of the controller, the root locus of the system was expected to have the dominant pole. Finally, the gain of system and the pole position of controller were obtained according to the modulus value formula and phase angle formula. The results show that the FSM control system based on the improved root locus algorithm has good dynamic performance and can suppress the mechanical resonance efficiently. The method is feasible and versatile.