动载体光电平台视轴稳定精度的检测

摘要

A novel measurement scheme for the stabilization accuracy of a Line of Sight(LOS) in an e-lectro-optical imaging system on a moving carrier is proposed. The principle of optical measurement for LOS stabilization accuracy is briefly introduced, and the optical design of an autocollimator with a large field of view and a detection algorithm for the light-spot position are investigated. The autocollimator is used to test orientation changes of the LOS which is represented by a mirror fixed on the frame of the electro-optical imaging system. A high-speed CMOS camera for the collection of images and an algorithm for image registration based on Phase-only Correlation (POO are employed to detect sub-pixel level displacement of light-spot images by calculation of the normalized cross-power spectrum between pairs of images. The scheme has been used in the LOS stabilization accuracy measurement system, and a calibrating experiment is set up using a Leica theodolite. The experimental results show that the RMS error of the angular measurement is less than 2 μrad when the field of view is ±1° and the sampling rate is 500 frame/s. The dynamic measurement can meet the system requirements ofa larger field of view and a greater precision.%提出一种动载体光电平台视轴稳定精度的检测方法.介绍了光学测量原理,讨论了光电平台视轴稳定精度检测系统的实施路线,并对该系统使用的自准直光学成像系统、高速数字CMOS相机和光斑检测算法进行了研究.由安装在光电平台照准架上的平面反射镜反映光电平台视轴指向角度的变化,用高速数字CMOS相机采集图像,并通过计算图像之间归一化的互功率谱和采用相位相关配准算法检测光斑的亚像元级位移量实现了光电平台视轴指向角度的精确测量.将该方法应用于光电平台视轴稳定精度检测系统进行Leica经纬仪标定实验,结果显示,在视场检测范围为士1°、图像采样频率为500 frame/s时,检测误差＜2 μrad,表明该方法实现了动态测量并满足高精度、大视场的检测要求.