离轴反射望远镜整体旋转扫描机构设计研究

发布时间：2018-05-11 14:01

本文选题：望远镜整体旋转 + 离轴反射式　；参考：《中国科学院大学(中国科学院上海技术物理研究所)》2017年硕士论文

【摘要】：随着航天航空技术的进步,卫星遥感展现出大范围、高频度和实时观测的优势。扫描机构是许多高空间光学遥感仪器接受地物光学信息的第一个环节,扫描机构的结构性能的好坏与仪器的成像质量息息相关。本课题所设计的系统采用离轴反射式旋转望远镜整体360o圆周旋转+半角镜的物方扫描,具有视场大,可以实现从可见光至热红外谱段的星上定标,更好地抑制杂散光、降低偏振敏感度和实现实时定标,提高了系统的定量化应用水平。在结构上,整体扫描方式大大消解了“扫描镜”的旋转剪切应力、地面重力,安装误差对面型的扭曲。本文分析系统的光学设计方案,扫描系统各组成部分及其工作原理,并分析研究了机械结构、各部件的选取原则和设计思路,最终确定了望远镜整体旋转扫描系统机械结构总体方案。选取执行电机和传感器,选定反射镜材料和固定方式等系统机械部件的设计。设计了半角镜系统的结构。充分考虑了半角镜自身的动力学特性,比对几种连接方式,对半角镜机构的镜体、轴承、电机作连接方式选择。对望远镜运动机构进行了静平衡和动平衡分析,在MSC.ADAMS软件中建立了镜筒的多体动力学有限元仿真模型,得出了镜筒的量分布情况和连续扫描工况下的轴承受力情况。通过仿真优化设计将轴承受力达到最小。最后对望远镜系统和半角镜系统进行了基于ANSYS的仿真分析,在仿真实验中获得了其x,y,z方向上的一阶和二阶固有频率。根据Ansys的分析结果分析薄弱位置,对望远镜镜筒进行相应的添加肋板和辅助支撑进行加固,最终达到了设计要求。总之,本课题把有限元的技术与光机结构设计结合,应用在工程分析中建立了望远镜扫描机构的动力学虚拟样机模型、扫描系统有限元模型。总结出工程中利用有限元分析的常用手段与通用流程,故而本课题的研究内容具有一定的工程意义和使用价值。
[Abstract]:With the development of aerospace technology, satellite remote sensing shows the advantages of wide range, high frequency and real time observation. Scanning mechanism is the first link for many high spatial optical remote sensing instruments to receive optical information of ground objects. The structure and performance of scanning mechanism are closely related to the imaging quality of the instrument. The system designed in this paper uses the whole 360 o circumferential half-angle mirror of the off-axis rotating telescope to scan the object square. It has a large field of view, which can realize the calibration of satellite from visible light to thermal infrared spectrum, and can better suppress stray light. Reduce polarization sensitivity and realize real-time calibration, and improve the application level of the system. In structure, the whole scanning method greatly eliminates the distortion of the plane shape caused by the rotating shear stress, ground gravity and installation error of the "scanning mirror". This paper analyzes the optical design scheme of the system, each component of the scanning system and its working principle, and analyzes and studies the mechanical structure, the selection principle of each component and the design idea. Finally, the overall scheme of mechanical structure of the whole rotating scanning system of telescope is determined. Select executive motor and sensor, select mirror materials and fixed system mechanical parts design. The structure of half angle mirror system is designed. The dynamic characteristics of the semi-angle mirror are fully considered, several connection modes are compared, and the connection modes of the mirror body, bearing and motor of the half-angle mirror mechanism are selected. The static and dynamic balance analysis of the telescope motion mechanism is carried out. The finite element simulation model of the multi-body dynamics of the mirror barrel is established in the MSC.ADAMS software. The quantity distribution of the mirror barrel and the bearing force under the continuous scanning condition are obtained. The bearing force is minimized by simulation optimization design. Finally, the first and second order natural frequencies of the telescope system and the half angle mirror system are obtained in the simulation experiment based on ANSYS. According to the analysis result of Ansys, the weak position is analyzed, and the telescope mirror tube is strengthened with rib plate and auxiliary support. Finally, the design requirements are met. In a word, the finite element technique is combined with the optical machine structure design, and the dynamic virtual prototype model and the scanning system finite element model of the telescope scanning mechanism are established in the engineering analysis. This paper summarizes the common means and general flow of finite element analysis in engineering, so the research content of this project has certain engineering significance and practical value.
【学位授予单位】：中国科学院大学(中国科学院上海技术物理研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：V443.5;TP73

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