大口径反射镜重力卸载设计  

Gravity Unloading Design of Large Aperture Reflect Mirror

作　　者：姜彦辉 刘涌[1] 邹宝成 胡嘉宁 孙欣[1] 武永见[1] JIANG Yan-hui;LIU Yong;ZOU Bao-cheng;HU Jia-ning;SUN Xin;WU Yong-jian(Beijing Institute of Space Mechanics&Electricity,Beijing 100094)

机构地区：[1]北京空间机电研究所

出　　处：《环境技术》2020年第1期81-85,98,共6页Environmental Technology

基　　金：可见光、红外与激光主被动复合测绘相机及应用技术(D040106)

摘　　要：为满足人类对相机更高性能的要求,空间反射镜的口径也逐渐增大。大口径反射镜由于其刚度低,在重力环境下,不同支撑方法对反射镜面形影响较大,如何在光学加工与检测过程中保证反射镜的支撑方式具有较高的面形精度是一个难题。本文针对Φ1.4 m大口径轻质反射镜重力卸载方案,对比分析了光轴水平状态下吊带卸载、背部离散多点支撑及光轴竖直状态下背部多点离散支撑各方案的可行性,最终选取了光轴竖直状态下多点离散支撑卸载方案。有限元分析表明,反射镜卸载面形精度RMS值变化量为1.53 nm,应用此种方法支撑的反射镜最终加工面形精度RMS变化量为0.012λ。本文所设计的重力卸载方案有限元仿真及试验结果均达到设计要求,为此类大口径轻质反射镜的重力卸载提供技术基础。In order to meet higher performance requirements of space cameras,the aperture of the space reflect mirror gradually become larger.In view of the low stiffness,the different support methods of the large aperture reflect mirror have huge impacts on surface in gravity environment,therefore,it is a difficult problem to ensure the support method of mirror has a high precision in the process of processing and testing.In this paper,the gravity unloading scheme of theΦ1.4 m large aperture lightweight mirror is compared and analyzed in the terms of the feasibility of the strap unloading scheme and the back discrete multi-point support scheme in the horizontal state of the optical axis,the back discrete multi-point support in the vertical state of the optical axis,and finally,the back discrete multi-point support scheme is selected in the vertical stated of the optical axis.The result of finite element analysis shows that the image accuracy RMS of the mirror is 1.53 nm,and the final machining image accuracy RMS of the mirror supported by this method is 0.012λ.The finite element simulation and test result of the gravity unloading scheme designed in this paper meet the design requirements,which provides a technical basis for the gravity unloading of large aperture lightweight reflect mirror.

关 键 词：反射镜 重力卸载 吊带卸载 背部多点离散支撑 有限元仿真 

分 类 号：TH703[机械工程—仪器科学与技术]