光电工程, 2015, 42 (2): 28, 网络出版: 2015-02-15
针对温度影响的空间反射镜局部面形优化
Optimization of Local Space Mirror Surface Shape Influenced by Temperature
摘要
对于采用背部支撑的空间相机反射镜, 温度变化会造成其支撑孔附近的局部面形精度降低, 形成局部环形缺陷, 从而影响光学系统中对应视场的成像质量。为了提高反射镜的温度适应性, 通过增加支撑结构的柔性, 降低局部连接刚度的方法, 优化设计出一种柔性结构。对反射镜组件进行仿真分析, 结果表明, 在反射镜组件温度降低 4℃的情况下, 优化结构后的反射镜的中间支撑孔附近的局部视场面形的 PV=4.9 nm, RMS=1.0 nm, 与优化前(PV=16.6 nm, RMS=3.5 nm)相比, 精度提高了 3倍; 全局视场面形的 PV=16.3 nm, RMS=3.2 nm, 相比优化前 (PV=30.2 nm, RMS=5.2 nm), 精度也得到提高; 反射镜组件在优化前的 1阶基频为 191 Hz, 优化后的 1阶基频为 183HZ, 数据基本保持不变; 反射镜在重力作用各工况下, 优化结构前后的全局视场面形的 PV值和 RMS值基本保持不变。说明新的柔性支撑结构在保证了反射镜动、静态刚度的前提下, 提高了反射镜的温度适应性, 降低了温度变化对反射镜支撑孔附近局部面形精度的影响, 提高了光学系统局部视场下的成像质量, 达到了提高全视场下成像质量的目的。
Abstract
For the use of mirrors in space camera back support, the change in temperature will cause a partial supporting surface accuracy of the hole near the lower annular formation of local defects, which affect the quality of the optical system corresponding to the imaging field of view. In order to improve the adaptability to temperature mirror support structure by increasing the flexibility, and reduce the local connection stiffness, design of a flexible structure is optimized. Mirror assembly simulation for analysis, in the mirror assembly temperature 4℃ lower case, optimize the structure of the reflector around the middle hole of the support as the local scene shaped PV=4.9 nm, RMS=1.0 nm. Compared with the former (PV=16.6 nm, RMS=3.5 nm), and its accuracy is improved by 3 times, the global field shape PV=16.3 nm, RMS=3.2 nm. Compared to before optimization (PV=30.2 nm, RMS=5.2 nm), its accuracy is improved. Mirror assembly in the 1 order frequency before the optimization is 191 Hz and after the optimization are 183 Hz, basically unchanged. Mirrors in various gravity conditions, depending on the global scene shaped to optimize PV and RMS values before and after the basic structure remains unchanged, which illustrate that the new flexible support structure ensures the mirror dynamic, static stiffness, improve the temperature adaptability of mirror, reduce the influence of temperature changes to the mirror support hole near the local surface shape accuracy, and improve the imaging quality of local field optical system and imaging quality of all field goal.
秦承运, 沙巍, 张星祥, 任建岳. 针对温度影响的空间反射镜局部面形优化[J]. 光电工程, 2015, 42(2): 28. QIN Chengyun, SHA Wei, ZHANG Xingxiang, REN Jianyue. Optimization of Local Space Mirror Surface Shape Influenced by Temperature[J]. Opto-Electronic Engineering, 2015, 42(2): 28.