空间相机高精度可重复式次镜展开机构设计  

Design of a High-Precision Repeatable Secondary Mirror Deployment Mechanism for Space Cameras

作　　者：宋俊伟 陶小平[1] 徐明林[1,3] 王循 Song Junwei;Tao Xiaoping;Xu Minglin;Wang Xun(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,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：《激光与光电子学进展》2024年第5期419-427,共9页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(51827806)。

摘　　要：对于空间相机来说,高分辨率要求相机的焦距要长,长焦距则会导致主次镜间距变大,从而导致空间相机的体积增大,空间利用率降低。为了充分减小空间相机发射时的包络尺寸,降低空间相机的发射成本,针对同轴三反式光学系统设计了一种基于空间四连杆的高精度可重复式次镜展开机构。对该次镜展开机构进行误差分析,对次镜展开机构的模型进行有限元分析以评估机构的可靠性,并设计了机构可重复性实验验证次镜展开机构的可重复性。次镜展开机构折叠后空间相机光轴方向长度由875 mm压缩为324 mm,体积压缩63%,展开状态下的基频为96.64 Hz,重复展开位移极限误差最大为15.61μm,倾斜极限误差最大为16.89″。结果表明,该机构实现了空间相机体积的压缩,且锁紧状态下的基频符合在轨使用要求,重复精度满足光学系统要求,能够适应微纳卫星的运载条件,可以应用于航天实践中。High-resolution imaging in space cameras requires a long focal length,leading to increased distance between the primary and secondary mirrors.Consequently,this results in a larger camera volume and inefficient space utilization.To decrease the launch cost and envelope size of the space camera during launch,a high-precision,repeatable secondary mirror deployment mechanism is designed based on the four-link space structure for the coaxial three-mirror optical system.The mechanism’s error was analyzed,and finite element analysis was conducted to evaluate its reliability.Additionally,a repeatability test plan was devised to ensure the mechanism’s consistency.Following the folding of the secondary mirror deployment mechanism,the optical axis direction length of the space camera is reduced from 875 mm to 324 mm,achieving a 63%compression in volume.In its unfolded state,the mechanism exhibits a fundamental frequency of 96.64 Hz.The maximum deviation in repeated unfolding displacement is measured at 15.61μm,and the maximum inclination deviation is 16.89″.These results demonstrate the mechanism’s effectiveness in minimizing the space camera’s volume and meeting the in-orbit requirements,attributable to its locked state fundamental frequency.Furthermore,the mechanism maintains the optical system’s repeatability and can accommodate the payload conditions of micro and nano satellites,making it an ideal solution for aerospace applications.

关 键 词：空间相机 次镜展开机构 有限元分析 可重复性实验 

分 类 号：TH703[机械工程—仪器科学与技术]