1.8 m长条形轻质SiC反射镜支撑位置设计  

Support Position Design of 1.8 m Rectangular Light-Weight SiC Mirror

作　　者：龙荃 李宗轩[1,3] 张德福[1,3] 李清雅[1,3] 任书慧 徐佳坤 Long Quan;Li Zongxuan;Zhang Defu;Li Qingya;Ren Shuhui;Xu Jiakun(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,China;University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory of Space-Based Dynamic&Rapid Optical Imaging Technology,Chinese Academy of Sciences,Changchun 130033,Jilin,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049 [3]中国科学院天基动态快速光学成像技术重点实验室,吉林长春130033

出　　处：《光学学报》2024年第13期240-248,共9页Acta Optica Sinica

基　　金：中国科学院青年创新促进会项目(2021218);中国科学院天基动态快速光学成像技术重点实验室项目(CXJJ-22S040);“旭光”人才计划(E1X011Y6X0)。

摘　　要：反射镜在自重作用下的形变是影响光学表面质量的重要误差源之一。对于圆形的反射镜来说,其内部有一个中性面,当柔性支撑的回转中心与中性面重合时,反射镜表面受到重力影响后的形变最小。但由于长条形反射镜不再具有回转对称性,其原有的中性面位置公式将不再适用。本文提出了一种长条形反射镜中性面位置即最佳安装位置的计算方法。通过计算柔性支撑的柔度矩阵,得到反射镜组件的整体力学模型,并以此推导出了长条形反射镜中性面位置计算公式。最终将其与有限元分析和光学检测试验得到的结果进行对比,验证了中性面位置计算公式的准确性。在光学检测试验中,反射镜组件在不同方向重力作用下表面面形的均方根(RMS)值均小于0.03λ;反射镜扫频振动试验得到的三个方向上的最小共振频率分别为106.30、151.55、104.00 Hz。该结果满足反射镜组件对于面形精度、结构刚性和稳定性的要求。Objective The large-scale off-axis three-mirror anastigmatic(TMA) space-borne telescope enables the space optical remote sensing camera to meet the requirements of light weight, long focal length, large field of view, and high resolution.Meanwhile, it has a compact structure and many optimizable variables without dispersion and center blocking, which has become a research hotspot. The rectangular space mirror with a large size and high aspect ratio is an important part of the TMA, and the size of its structural rigidity, stability, the advantages and disadvantages of surface figure error, and thermal stability will directly affect the imaging quality of the whole camera. However, due to its structure asymmetry, the flexible mount design for the mirror of the TMA space camera, and the mounting and positioning of the mirror assembly are current technical difficulties. A reasonable support scheme design can eliminate the deformation of the mirror and its support assembly in processing and assembly to ensure the smaller surface figure error of the mirror. For a mirror where the gravity direction is perpendicular to the direction of the optical axis, there exists in the mirror body such a plane of action: If the actual support point of the flexible mount is on or near this surface, the gravitational moments of the various parts of the mirror body are balanced and the bending deformation of the mirror body is minimal due to its weight. This plane of action is known as the neutral plane of the mirror. For a circular mirror, the neutral surface is a plane at some distance from the center of gravity and perpendicular to the optical axis. However, as the rectangular space mirrors employed in TMA lose rotational symmetry compared to traditional circular mirrors, the supporting theories and empirical formulas in circular mirrors are difficult to extend to rectangular space mirrors.Methods We introduce a method to calculate the neutral plane position and optimal mounting position for a rectangular space mirror. First, we cond

关 键 词：离轴三反相机 长条形反射镜 中性面 柔性支撑 面形误差 

分 类 号：V19[航空宇航科学与技术—人机与环境工程]