光电瞄具多光轴平行性检测系统的设计与研究

Design of a detection system for multiple optical-axis parallelism in an electro-optical sighting telescope

为了精准地测量光电瞄具多光轴的平行性,采用大口径离轴抛物面反射镜平行光管的多光轴检测方法进行了理论分析,并设计了完整的测量系统(包括光学成像系统、控制系统、图像采集与处理系统)。该系统采用离散余弦变换系数作为评价标准,实现了高精度的自动对焦;采用大口径离轴抛物面反射镜满足不同型号瞄具的测量,实现了可见光、近红外和远红外3种光学系统的光轴平行性的自动检测。结合一种光电瞄具成品进行了实际测试,当光轴之间偏差角为0.04mrad～0.08mrad时,相对误差在13%以内,此范围可认为是系统检测角度的下限。结果表明,该系统减小了人为读数等主观原因造成的误差,通用性强、检测效率高,精度满足需求。

In order to achieve accurate measurement of multiple optical-axis parallelism of an electro-optical sighting telescope, a detection system for multiple optical-axis parallelism was designed based on a large-calibre off-axis concave parabolic mirror. The whole system, including optical imaging system, controlling platform and image acquisition and processing system, was designed. Using discrete cosine transform coefficients as evaluation standard, high-precise auto- focusing was achieved. Using a large-calibre off-axis concave parabolic mirror, the demands of various kinds of electro- optical sighting telescopes measurement were meeted. The automatic measurement of optifcal-axis parallelism among light axis, far-infrared axis and near-infrared axis was achieved. The actual measurement was carried out for a certain electro- optical sighting telescope. When the deviation angle among muhiple optical-axis was between 0. 04mrad and 0. 08mrad, the relative error was less than 13%, considered as the limit of system detection angle. The results showe that the detecting system decreases the error of human factor and is universal and high efficient. The accuracy of measurement also meet the requirements.