倾斜镜系统动态耦合数学模型的建立方法

Dynamic modeling of input-output coupled piezoelectric fast steering mirror

主要探究了在传感器采样频率较高(如高速相机、位置传感器)、倾斜镜动态特性不可忽略的情况下,如何基于实验数据建立开环倾斜镜系统的动态耦合数学模型的问题。分析了系统的动态特性以及输入与输出之间的耦合,提出了基于倾斜镜系统的输入输出数据、采用子空间辨识算法建立倾斜镜系统动态耦合数学模型的方法,并通过实验评估了模型的准确性和建模方法的可行性。实验结果显示,通过该方法所建立的倾斜镜动态耦合模型的VAF值达到95%,模型准确性相比传统的静态模型有了很大提高,验证了建模方法的可行性。研究成果可用于闭环倾斜镜系统优化反馈控制器的设计,提高系统对于光束偏移矫正的性能。

Dynamic modeling of an input- output coupled piezoelectric fast steering mirror（ FSM） was discussed, especially in case that the sampling frequency of the sensor is so high（e.g., high-speed camera or position sensitive device is used） that the dynamics of the FSM is significant and can ′ t be neglected.The dynamics and input-output coupling in the FSM was analyzed. A method was proposed to model the dynamics and input-output coupling in the FSM, based on the input-output data and the subspace identification algorithm. Experiments were carried out for data collection and validation of the proposed method. The results show that the variance-account-for（VAF） of the dynamic input-output coupled model is as high as 95%, indicating high accuracy of the model. Comparison was made between the proposed model and static model as well, showing significant improvement on the model accuracy. The result can be applied in optimal feedback controller design for closed-loop FSM systems, to improve the closed-loop performance in laser beam drifting correction.