移动式米级主镜高刚度支撑结构设计  

Design of high stiffness support structure for mobile meter-level primary mirror

作　　者：贺昌龙 吴小霞[1] 赵勇志[1] 曹鹏宇 王越群 HE Changlong;WU Xiaoxia;ZHAO Yongzhi;CAO Pengyu;WANG Yuequn(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,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

出　　处：《红外与激光工程》2024年第11期201-212,共12页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(12133009);吉林省科技发展计划项目(20210401162YY);中国科学院关键核心技术攻关项目(YZQT024)。

摘　　要：为了提高移动式米级主镜的位姿精度,针对车载光学检测系统的1.57 m主镜,提出采用柔性切向杆定位机构结合杠杆平衡重支撑机构的侧支撑方式,与轴向Whiffletree支撑方式相结合,保证主镜的面形精度和位姿精度。对该解耦式支撑方式进行了原理分析,杠杆平衡重支撑机构承载主镜重量,柔性切向杆定位机构实现主镜定位,解耦侧支撑和侧定位,主镜径向下沉量理论上为0,因此该支撑方式可大幅降低主镜径向下沉量,提高主镜位姿精度和支撑刚度。对支撑性能进行分析评估,相较于只采用六组柔性切向杆的侧支撑方式,该解耦式侧支撑方式可将主镜下沉量由24.3μm降低到3.6μm;主镜最大综合面形误差约为9.6 nm RMS;整体模态最低固有频率达到54.93 Hz;随机振动分析中,支撑系统在X、Y、Z轴三个方向的最大位移响应分别为0.11、0.10、0.36 mm,最大应力响应为12.1 MPa;主镜在X、Y、Z轴三个方向的最大位移响应分别为1.6、9.7、12.3μm,最大应力响应为0.44 MPa。评估结果表明,该支撑方案可为主镜提供良好的面形精度和位姿精度,可有效适应车载运输。车载运输后实测主镜面形精度RMS为0.0237λ(λ=632.8 nm),验证了该支撑方案效果良好,且证明了有限元分析的准确性。Objective The large aperture mobile optical system has bad working conditions,and its support structure needs to ensure the surface shape accuracy,pose accuracy and support stiffness of the mirror after or when experiencing the turbulence and impact of vehicle transportation.Therefore,it is necessary to analyze and design the support structure of the large aperture mobile mirror in detail.Domestic researches on the support structure of mobile mirror mainly focus on mirrors with a diameter of no more than 500 mm and a small mass,and the support structure is simple,which is not suitable for the support of mobile meter-level mirrors.However,the support mode of traditional non-mobile meter-level large aperture mirrors and foreign mobile meter-level mirrors such as Stratospheric Observatory for Infrared Astronomy(SOFIA)usually adopts a set of tangential support mechanism to provide tangential support and tangential positioning at the same time,and the positioning mechanism in the device has a certain deformation due to the force,resulting in reduced positioning accuracy.For a system with a complex optical path,adding an adjusting mechanism to each link of the optical path to compensate for the pose error of the primary mirror will lead to complex system structure,increased cost and tedious installation.Therefore,it is necessary to develop a new tangential support mode of the mirror to improve the pose accuracy of the mobile meter-level mirror.Methods Aiming at the 1.57 m primary mirror of the vehicle optical detection system,this paper proposes the tangential support mode of 6 groups of flexible tangential rod positioning mechanism combined with 16 groups of lever counterweight supporting mechanism.The lever counterweight supporting mechanism carries the weight of the primary mirror,and the flexible tangential rod positioning mechanism realizes the primary mirror positioning,decoupling tangential support and tangential positioning,improving positioning accuracy and enhancing support stiffness.Combined with the axial W

关 键 词：反射镜支撑 高刚度结构 原理分析 移动式 解耦 

分 类 号：TH741[机械工程—光学工程]