摘要
如何进一步提升高性能米级空间反射镜轻量化率是大口径光机结构研制领域内的核心问题之一。本文为某高分辨率空间相机研制了通光口径Φ1200 mm的主反射镜,实现了面密度40 kg/m2的设计目标。碳化硅镜体采用凝胶注模成型及反应烧结工艺制备,将光轴水平状态作为检测状态以简化支撑结构,在半封闭式镜体内使用了主副筋交叉布置、立壁增加减重孔等轻量化手段,用分布式基准面取代传统基准设置,将基准面加工面积减少80%以上、提高了加工效率。通过参数化建模与集成优化,确定了镜体最优结构参数组合,最终镜体设计重量为46.9 kg。光轴水平时主镜自重变形RMS值仅2.87 nm,镜体自由基频为602 Hz,主镜具有良好的动、静力学特性。镜坯经机械加工后实测重量为51.3 kg、超重约9.4%,镜面厚度不均匀性小于1 mm,当前镜面已抛光至面形精度RMSλ/8 (λ=632.8 nm),未见印透效应。
How to further improve the lightweight ratio of high-performance meter-level space mirrors is one of the core issues in the field of large aperture optomechanical structure design.In this paper,a primary mirror with a clear aperture ofΦ1200 mm was developed for a high-resolution space camera,which achieves the goal of designing area density below 40 kg/m2.The SiC mirror blank was prepared by gel injection molding and reaction sintering process.The state of the optical axis being horizontal was taken as the testing state to simplify the supporting structure.Novel lightweight measures such as an alternate arrangement of main and auxiliary stiffeners and the addition of lightweight holes on vertical walls were used inside the semi-closed mirror blank.The distributed datums were used to replace traditional datum settings,which reduces the machining area of datums by more than 80%and improves machining efficiency.Through parametric modeling and integrated optimization,the optimal structural parameter combination of the mirror blank was determined,with the final design weight of 46.9 kg.The RMS value of self-weight deformation of the mirror blank is only 2.87 nm under the state of the optical axis being horizontal,and its free fundamental frequency is 602 Hz,indicating that the primary mirror proposed in this paper has good dynamic and static characteristics.After machining,the measured weight of the mirror blank is 51.3 kg,about 9.4%overweight,and the facesheet is about 1-mm thicker than the design.At present,the mirror has already been polished to RMSλ/8(λ=632.8 nm)of surface shape accuracy,with no obvious print-through effect observed.
作者
袁健
张雷
姜启福
裴思宇
龚小雪
Yuan Jian;Zhang Lei;Jiang Qifu;Pei Siyu;Gong Xiaoxue(Chang Guang Satellite Technology Co.,LTD,Changchun,Jilin 130033,China;School of Mechanical Engineering and Automation,Northeastern University,Shenyang,Liaoning 110819,China)
出处
《光电工程》
CAS
CSCD
北大核心
2023年第4期37-46,共10页
Opto-Electronic Engineering
基金
吉林省科技发展计划项目(20210509052RQ)。
关键词
空间光学
反射镜
轻量化
大口径
反应烧结碳化硅
space optics
mirror
lightweight
large aperture
reaction bonded silicon carbide
作者简介
通信作者:张雷,18686344285@163.com。
