摘要
为降低子镜促动器负载,保证拼接式主镜的面形精度和稳定性,针对子镜组件进行了一体优化设计。根据子镜组件设计要求初步确定了子镜的结构形式,基于反射镜背部三点支撑方案提出了一种开槽横梁多轴柔性支撑结构。为解决组件一体优化设计中引入变量过多,不易收敛的问题,设计了一种基于多岛遗传与梯度优化的组合优化算法。建立了以结构重量、面形精度为目标的优化模型,对子镜组件进行了一体设计、工程分析及试验验证。工程分析结果表明:子镜组件结构重量为1.74 kg,X、Y、Z三个方向上的基频均在400 Hz以上,面形精度均控制在5 nm以内。最后对子镜面形进行了检测,结果显示:子镜面形精度的RMS值为0.019λ(λ=632.8 nm),满足优于λ/50的设计要求,验证了设计和分析的准确性,表明针对子镜组件的一体优化设计方法是合理的,为空间相机反射镜支撑结构组件级一体化设计提供了新思路。
The optimization target of traditional light-weight methods is a single part generally,which can not make the whole component achieve the design goal of lightest weight and highest surface figure precision. It can not meet performance indexes due to the strict limitation of the carrying capacity of actuator and mirror′s material. A Primary Mirror Segment Assembly( PMSA)is designed integrated to reduce the load of the segment actuator and ensure the surface figure and stability of the splicing primary mirror. The points surpport on the mirror back is selected as the support method through the topology optimization,the mass distribution of the back of the mirror and the distribution of the removable part are obtained. The initial structure of the mirror is determined based on back with triangular hole for light-weighting. A multiaxis flexible support structure with slotted beams based on the support method is put forward. Component integration design introduces too many parameter variables,resulting in a large amount of calculation,long iteration time and difficulty in convergence. A combinatorial optimization algorithm based on multi-island genetic and gradient algorithm to solve the problem of too many variables and difficulty in convergence is designed, and it is applied to optimization design of the segment. The combinatorial optimization algorithm′s tactics is that the sensitive area of the design space is roughly located by the multi-island genetic algorithm,and the exact positions are optimized by using the gradient optimization algorithm in the area.The tactics makes full use of the advantages of global optimization algorithm in overall design space traversal and gradient optimization algorithm in local area convergence speed faster. It is established that multiple-object optimization model which combines structure mass,the surface figure error under the influence of gravity along Y-axis( dectction direction)and the surface figure error under the effect of 5℃temperature change as objectives. The optim
作者
杜一民
高雁
许博谦
张春悦
匡也
DU Yimin;GAO Yan;XU Boqian;ZHANG Chunyue;KUANG Ye(CAS Key Laboratory of On-orbit Manufacturing and Integration for Space Optics System,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2022年第4期285-294,共10页
Acta Photonica Sinica
基金
国家重点研究发展计划(No.2016YFE0205000)。
关键词
拼接式主镜
面形精度
子镜组件
组合优化算法
一体设计
工程分析
面形检测
Splicing primary mirror
Surface figure error
Primary mirror segment assembly
Combinatorial optimization algorithm
Integrated design
Engineering analysis
Surface test
