反射镜片高度对快反镜测量误差的影响及补偿

Effect and compensation of the reflector lens' height on the measurement error of fast steering mirror

在高精度光电跟瞄系统中,快速反射镜(fast steering mirror,FSM)是精跟踪通道中的核心元件,能够实现转动角亚微弧度的分辨率。测量误差直接影响到跟瞄系统的控制精度,其中,FSM镜片反射面高度对误差的影响显著,在实际跟踪控制中必须予以补偿与校正。以某型搭载快速反射镜的实验转台测量模型(测量精度为±50μrad)为基础,理论推导了反射镜片反射面高度引起的误差模型,并利用系统辨识的最小二乘估计算法求取出误差特性参数,进行误差补偿。实验结果表明,经过补偿后的镜片高度对误差的影响缩小到±2μrad。

In the high-precision electro-optical tracking and pointing system, fast steering mirror is the core component in the fine channel. It can realize the resolution of the rotation angle of sub micro radian. The measurement error has a di- rect influence on the control precision of the pointing and tracking system, in which the height of the FSM reflector lens affects the error significantly, and it must be compensated and corrected in the precision tracking control. Based on the measurement model of one type of turntable equipped with a fast steering mirror of which measuring accuracy is about ±20μrad , the error model induced by the reflector lens＇ height is deduced and using the least squares estimation algo- rithm of system identification to extract the error characteristic parameters. The experimental results show that the influ- ence of lens＇ height on the error is reduced to ±2 μrad.