大口径望远镜主镜径向偏心误差检测技术

Radial Eccentricity Error Detection of Primary Mirror of Large Aperture Telescopes

为保证大口径望远镜主镜在加工、镀膜和装调过程中的径向公差要求,提出一种基于图像处理的实时检测大口径望远镜主镜径向偏心误差的方法,利用光学成像系统对沿轴线运动的主镜的内孔和固定于主镜支撑结构底座的参考孔进行成像,通过边缘提取和质心算法计算主镜相对于支撑结构的径向偏心误差。经实验验证,该方法可实现对主镜径向偏心误差的实时测量,且测量精度满足主镜的径向公差要求。

In order to achieve the radial tolerance requirement in the process of machining,coating and aligning of the primary mirror of large aperture telescopes,we present a method based on image processing to realize the realtime detection of the radial eccentricity error of the primary mirror.Using optical imaging systems to take pictures of the reference hole which is fixed to the base of the primary mirror support structure and the inner hole of primary mirror while it is moving along the axis,the radial eccentricity error of the primary mirror with respect to the support structure is calculated by the edge extraction and the centroidal algorithm.Experimental results show that this method can realize the real-time measurement of the radial eccentricity error of the primary mirror,and the accuracy satisfies the radial tolerance requirement.