大型空间相机出瞳镜精密调整结构设计与分析

	大型空间相机出瞳镜精密调整结构设计与分析
其他题名	Design and analysis of precise adjusting structure ofexit pupil mirror for large space camera
	袁健
学位类型	硕士
导师	任建岳
	2015-10
学位授予单位	中国科学院大学
学位专业	光学工程
关键词	空间相机出瞳调整结构变形镜重力变形热变形柔性结构空间环境适应性像差校正能力
摘要	随着空间技术的不断进步，空间相机在国民经济中所发挥的作用日益重要，大视场、高分辨率已经成为现代空间相机的发展方向。传统的轻量化非球面反射镜由于自重变形大、温度稳定性差等问题，会向系统内引入较大的波像差，从而限制空间相机分辨率的提高，如何校正大口径主镜的波像差是发展高分辨率空间相机的核心问题之一。基于主动光学原理的变形镜技术，可以对系统内发生畸变的波前进行充分的校正，有效地提升光学系统的成像质量，在大口径空间相机中拥有广阔的应用前景。为了校正高分辨率空间相机中由大口径主镜引入的波像差，可以将变形镜装置应用到空间相机的出瞳调整结构中，通过对出瞳镜面形的精确控制，来补偿系统内的波前畸变。出瞳镜精密调整结构自身性能的优劣将会直接影响到出瞳镜的像差校正能力，是提升空间相机分辨率的关键，其设计问题则是高分辨率空间相机在研制过程中的核心问题之一。特殊而复杂的空间工作环境要求出瞳镜精密调整结构具有良好的空间环境适应性。为了能够应对微重力环境、变化的温度场和粒子辐照等恶劣的工作条件，出瞳调整结构必须在保证出瞳镜具有优良的面形质量和像差校正能力的前提下，具有良好的温度适应性和动、静力学特性。本文讨论了大型空间相机出瞳镜精密调整结构的设计问题，比较了不同结构的机械性能，对影响出瞳镜校正能力的主要因素展开了研究，设计出一种结构紧凑、简单可靠、性能优良的出瞳镜精密调整结构。本文的研究内容可以主要概括为以下几点： 1，阐述出瞳镜精密调整结构的结构组成。结合两种常见空间相机的成像特点，讨论了出瞳调整结构的应用场合，描述其在空间相机中的位置。从理论上，推导了出瞳调整结构的数学原理和工作过程，为出瞳调整结构的应用打下基础。给出空间相机用出瞳调整结构的具体设计准则，从众多结构形式的变形镜中通过比较，选择了连续镜面分立促动器式变形镜作为出瞳镜精密调整结构的最佳形式,给出该形式变形镜的结构组成以及各部分的设计要点。 2，给出出瞳镜精密调整结构的具体设计过程。阐述了反射镜、促动器组件、支撑底座、装埋件等主要结构的设计思路，提出筋板式结构和实体式结构两种支撑底座，从加工工艺和空间环境适应性出发，确定了各主要零件的材料组合。本文设计的出瞳精密调整结构布局紧凑，采用的元件个数较少，系统可靠性高，为接下来的研究和优化提供了坚实的基础。 3，对影响出瞳调整结构工作性能的诸多因素进行分析，并对出瞳调整结构进行优化。运用有限元方法，建立相应的结构模型，模拟空间工作环境，进行了仿真分析，掌握了出瞳镜精密调整结构的力学性能和热稳定性等特征。讨论了应该重点考察的工况，以及如何模拟空间工况的问题。从动、静力学特性和温度适应性等角度，对比了两种不同结构形式的支撑底座，并参考空间反射镜的支撑方法，研究了不同支撑方案对调整结构的影响，确定采用CFRP 制作的实体式支撑底座、并结合背部三点支撑是出瞳镜精密调整结构的最佳支撑方案。指出了柔性结构在出瞳镜精密调整结构的设计过程中所发挥的重要作用，参考了多种空间相机中常用的柔性结构，向调整结构中的关键部件，如促动器底座、推杆，合理地引入了柔性结构，从而提高了其空间环境适应性。 4，研究了该结构的空间环境适应性和像差校正能力。利用该结构对典型工况（包括各向重力和温升工况）下的出瞳镜变形进行展平实验，获得展平后的结果近似于标准平面。使用该出瞳镜精密调整结构对前36 阶泽尼克多项式对应的基元波面进行拟合，获得的残差均较小，从而说明该调整结构可以对中、低阶像差进行有效地校正，其像差校正能力能够满足空间相机的使用要求。
其他摘要	With the continuous development of space technology, space camera is playing a more and more important role in the national economy, and large field of view and high resolution have become the future direction of modern space remote sensor. Due to self-weight deformation, thermal instability and other issues of traditional lightweight aspheric mirror, large wave aberration is introduced into the optical system, thus the resolution of space camera is limited, and how to calibrate the wave aberration of large aperture primary mirror is one of the core problems of the development of high resolution space camera. Based on the principles of active optics, deformable mirror technology which can be used to calibrate the distorted wavefront and improve the imaging quality of the optical system effectively, has wide application prospect in large aperture space optical system. In order to calibrate the wavefront aberration caused by large aperture primary mirror, deformation mirror device can be applied to the pupil adjusting structure of space camera to compensate the wavefront aberration through accurate controlling of pupil mirror. The design of the precise adjusting structure of exit pupil mirror is the core problem in the design of the deformable mirror, of which the performance will directly affect the correction ability of exit pupil mirror, and is the key link to improve the resolution of space camera. The special and complex space environment requires that the pupil adjusting structure has excellent spatial environment adaptability. In order to cope with the harsh conditions, such as microgravity environment, changing temperature field and particle irradiation, the pupil adjusting structure must have good dynamic and static characteristics and thermal adaptability, meanwhile it must ensure that the pupil mirror has excellent surface quality and aberration correcting ability. In this paper, the design problem of the precise adjusting structure of pupil mirror for large space camera is discussed, the mechanical properties of different structures are compared, the main factors affecting the aberration correction ability of pupil mirror are studied, and a scheme of precise adjusting structure of pupil mirror is given, which is compact, simple, reliable and has excellent working performance. The main contents of this paper include the following aspects: 1, the components of the adjustment structure of pupil mirror are described. In combination with the imaging features of two common space cameras, the application of the pupil adjustment structure is explained, and the layout in light path is given. Theoretically, the mathematical principle and working process of pupil adjusting structure are derived, and lay the foundation for its application. The specific design criterion of the adjustment structure of pupil mirror for space camera is given, and compared from different forms of deformable mirror, the structure with discrete actuators and continuous mirror is selected as its optimal form, and its components and corresponding key points for design are also given. 2, the details of the design process of the pupil adjusting structure are given. The design ideas of the main structures such as mirror, actuator assembly, support base, and embedded parts are described respectively. The two kinds of supporting bases are put forward, including solid structure and rib-board structure. The material combination of the main parts is determined, considering the processing technology and the space environment adaptability. The exit pupil precision adjusting structure proposed in this paper has compact structure, fewer components and high system reliability, and the design provides a solid foundation for future research and optimization. 3, the related factors that affect the performance of adjusting structure are studied, and the structure is optimized. Using finite element method, with the corresponding structure model build and space working environment simulated, the simulation analysis is carried out, and the mechanical properties and thermal characteristics of the exit pupil precise adjusting structure are obtained. What kind of space conditions should be emphasized and how to simulate them are discussed. From the perspective of dynamic and static characteristics and thermal adaptability, two forms of support base are compared. Referring to the support methods for space mirror, the influence of different support schemes on the adjusting structure is studied. The combination of solid support base made of CFRP and the method of three point back support is ascertained as the best support scheme for exit pupil mirror adjusting structure. It is pointed out that flexible structure plays an important role in the design of exit pupil mirror adjusting structure, and flexible structure is added to different main components, such as pushing rod and actuator base, referring to varieties of flexible structures in space camera. As a result, its spatial environment adaptability is improved significantly. 4, the spatial environment adaptability and aberration correcting ability of the structure are studied. Using this structure, the flattening test is carried out under typical working conditions, including the gravity and temperature rise, and the results are approximate to standard plane. The exit pupil adjusting structure is used to fit the wave elements, corresponding to the first 36 order of Zernike polynomials, and the residuals are small, which shows that the structure in this paper can effectively correct the aberrations of medium and low order, and its aberration correcting ability can meet the requirements of space camera.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/49273
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	袁健. 大型空间相机出瞳镜精密调整结构设计与分析[D]. 中国科学院大学,2015.

条目包含的文件
文件名称/大小	文献类型	版本类型	开放类型	使用许可
袁健.pdf（3610KB）	学位论文		开放获取	CC BY-NC-SA	请求全文