利用模拟退火优化快速反射镜控制策略

由于快速反射镜(FSM)系统在不同应用场合下需要不同有效带宽和闭环带宽,本文基于压电FSM控制系统建立系统模型,通过分析系统光轴抖动情况,对FSM控制算法进行了优化。首先,测得系统闭环Bode图,利用模拟退火算法求取系统传递函数;然后,结合辨识模型与模拟退火算法,提出了一种满足不同应用场合的全局最优PID控制器。最后,通过阶跃响应测试验证辨识模型的正确性,通过闭环实验测试验证最优控制器的有效性。结果表明,辨识模型与实际系统在中低频段符合得很好,阶跃响应曲线基本一致。采用最优控制器控制的系统有效带宽为35 Hz,闭环带宽为70Hz,跟踪精度提高了47%,基本满足当前实验环境下对FSM性能的要求。提出的系统显示良好的低频跟随能力和高频干扰抑制能力,跟踪精度高,器件损耗小。

Optimization of control strategy for FSM system by using simulated annealing algorithm

Fast Steer Mirrors(FSMs) should possess different effective bandwidths and close bandwidths under different situations. So this paper establishes a system model based on a piezoelectric FSM control system, and optimizes the control strategy for the FSM system by analyzing the jitter of an optical axis. Firstly, close loop Bode figure of the system was measured, the simulated annealing algorithm was used to achieve the modulation transfer function of the system model. By combining simulated annealing algorithm and the identified model, an optimal PID controller to meet all kinds of applications was presented. Finally, the step response tests were used to verify the correctness of the identification model, and the closed-loop tests were taken to validate the effectiveness of the optimal controller. Experimental results indicate that the indentified model fits the FSM system very well in low-middle frequency stage, its step response is similar. The system controlled by the optimal controller has a closed-loop bandwidth of 70 Hz, an effective bandwidth of 35 Hz, and the tracking accuracy is improved by 47%, meeting the requirements of FSMs in the current environment. It concludes that the system has good low frequency tracking ability and high frequency interference rejection ability, showing high tracking precision and low device loss.