低温大口径反射镜支撑装调系统研究

发布时间：2018-10-30 07:47

【摘要】：随着空间遥感器的迅速发展,大口径反射镜的支撑装调技术受到越来越多的研究者的重视。由于大口径反射镜的镜面在受到重力载荷和温度载荷下会发生较大变形而影响成像质量,本文设计了一套反射镜支撑装调机构来减小镜面变形。根据反射镜的工况和面形精度指标,本文依次完成了反射镜的基本尺寸的确定、反射镜的轻量化设计、反射镜支撑结构的设计及反射镜装调机构的设计,最后用有限元法分析镜面变形结果。本文研究内容分以下几部分展开。首先,已知离轴三反光学设计结果中的主镜口径,结合经验公式得到反射镜的厚度;对比各反射镜材料结合反射镜的工作环境确定反射镜材料为SiC;对大口径反射镜进行轻量化设计并通过有限元软件Solidworks Simulation分析对比各种支撑方式下的镜面变形量,最终确定其背部支撑方式。其次,通过对比分析国内外各类大口径反射镜支撑结构的优劣,结合反射镜镜面面形指标要求进行反射镜支撑结构的设计。详细介绍柔性铰链的力学性能和结构特点,确定支撑结构为基于柔性铰链的9点Kindle支撑,合理设计各支撑零件的尺寸,将支撑结构与镜座的连接副进行强度校核。再次,简要介绍球铰杆微位移实现原理和滚珠丝杠工作原理,根据反射镜系统的设计要求确定装调机构为双自由度回转机构配合滚珠丝杠移动平台的形式。根据工况及设计指标确定丝杠、步进电机、球铰杆等的尺寸和规格,最后对装调系统进行精度分析。最后,利用有限元软件Ansys Workbench 12.0对低温大口径反射镜系统进行仿真分析。分析分为三大部分:重力对大口径反射镜镜面面形的影响的分析;90K低温对大口径反射镜镜面面形的影响的分析;重力和90K低温共同作用下大口径反射镜镜面面形变化的分析。分析结果均满足镜面面形精度指标的要求,验证了该套反射镜支撑装调系统的合理性。
[Abstract]:With the rapid development of space remote sensor, more and more researchers pay attention to the supporting and adjusting technology of large aperture reflector. Because the mirror surface of large aperture mirror will deform greatly under gravity load and temperature load, a set of mirror supporting and adjusting mechanism is designed in this paper to reduce the deformation of mirror surface. According to the working condition and the precision index of the mirror, the basic dimension of the mirror, the lightweight design of the mirror, the design of the mirror supporting structure and the design of the mirror mounting and adjusting mechanism have been completed in this paper. Finally, the results of mirror deformation are analyzed by finite element method. The content of this paper is divided into the following parts. First of all, the diameter of primary mirror in the design result of off-axis triple mirror is known, and the thickness of mirror is obtained by combining the empirical formula, and the mirror material is determined to be SiC; by comparing each mirror material with the working environment of mirror. The light weight design of large aperture mirror is carried out, and the deformation of mirror surface under various supporting modes is analyzed and compared by finite element software Solidworks Simulation, and the back support mode is finally determined. Secondly, by comparing and analyzing the advantages and disadvantages of various kinds of large aperture mirror supporting structure at home and abroad, the mirror supporting structure is designed in combination with the mirror surface shape index. The mechanical properties and structural characteristics of the flexure hinge are introduced in detail. The supporting structure is determined to be a 9-point Kindle support based on the flexure hinge. The dimensions of the supporting parts are reasonably designed and the connection pairs between the supporting structure and the mirror seat are checked. Thirdly, the realization principle of ball hinge rod micro-displacement and the working principle of ball screw are briefly introduced. According to the design requirements of the reflector system, the form of double degree of freedom rotary mechanism and ball screw moving platform is determined. The dimensions and specifications of the screw, step motor and ball hinge are determined according to the working conditions and design indexes. Finally, the accuracy of the installation and adjustment system is analyzed. Finally, the low temperature large aperture reflector system is simulated and analyzed by finite element software Ansys Workbench 12.0. The analysis is divided into three parts: the analysis of the influence of gravity on the mirror shape of the large aperture mirror, the analysis of the influence of the 90K low temperature on the mirror shape of the large aperture mirror, and the analysis of the change of the mirror shape of the large aperture mirror under the combined action of gravity and 90K low temperature. The results of the analysis all meet the requirements of the specular shape precision index, and verify the rationality of the mirror supporting and adjusting system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V443.5

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