航空相机反射镜支撑结构设计与分析

Design and analysis for an aerial reflector supporting structure

卡塞格林光学系统中主次镜的面形精度是影响成像质量的重要因素,为了保证成像质量,卡式系统中主次镜面形误差需优于15.8 nm.针对某航空光电设备中的卡塞格林光学系统,设计了一种镜体柔性支撑结构.在主镜支撑设计中引入柔性铰链,对影响铰链刚度的主要参数进行优化设计.以重力和温度耦合为载荷约束条件,采用有限元方法对主次镜组件进行仿真分析,并用Zemike多项式对镜面进行拟合.拟合后主镜均方极值(RMS)为6.2nm,次镜均方极值(RMS)为2.7um,主次镜面形精度均方极值(RMS)优于1/40λ(λ=632.8 nm),满足光学设计指标要求.

The surface-profile precision of the main and second mirror is a key factor which influences the imaging quality.In order to guranteen the imaging quality,theroot-mean-square value of zhe main and second mirror should be better than 15.8nm.A flexible mirror supporting strurcture is designed for the aerial optic-mechanic photo.The structure parameters of the flexible is optimized through the finite element analysis software,on the working condations of gravity and temperrature.By taking the nodes locations and deformations of the surface as the input date of the matlab,the surface-profle precision was simulated.The RMS of the main mirror and the second mir ror was 6.2nm,less than 1/40λ(λ=632.8nm),the results can meet the requirements of the optic design.