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针对轻小卫星相机质量更轻、性能更好的设计要求,对空间某中等口径的长条形反射镜提出一种基于中心支撑形式的轻型优化设计方法。选用背部中心单点支撑形式,不仅从整体上减小了反射镜及其组件的质量,而且大大简化了支撑结构的设计。采用多目标集成优化的方法,提高了反射镜在Z向重力工况下的面形精度。设计了适用于中心支撑的柔性支撑结构,克服了中心支撑刚度低、动态可靠性差的缺点。仿真分析了反射镜及其组件的综合性能,并与背部三点支撑形式进行了比较。结果表明,中心支撑的反射镜质量更轻(3.36 kg),与实体反射镜相比,轻量化率达到了87%,组件质量也较三点支撑减小了24%;在X、Y、Z三轴方向1 g重力工况下的面形精度RMS值分别达到2.2、2.1、7.5 nm,优于三点支撑形式;4℃均匀温升载荷工况下的面形精度RMS值为2.8 nm,远小于设计要求的RMS≤12 nm;反射镜组件的一阶固有频率为135 Hz,重力作用下镜面的最大刚体位移为3.96μm。该设计在极大地减小了反射镜及其组件质量的同时,保证了反射镜的面形精度和组件的动、静态刚度,满足设计要求,为同类型空间反射镜的轻型优化设计提供了一种新思路。
Aimed at the design requirements of light and small satellite cameras with better quality and better performance, a lightweight optimization design method based on central support is proposed for a medium-sized long strip mirror in space. The choice of back center single point support form not only reduces the overall quality of the mirror and its components but also greatly simplifies the design of the support structure. The multi-objective integration and optimization method is adopted to improve the surface accuracy of the mirror under Z gravity conditions. The flexible support structure suitable for the central support is designed, which overcomes the disadvantages of low center support stiffness and poor dynamic reliability. The comprehensive performance of the mirror and its components is analyzed and compared with the three-point support form of the back. The results show that the center-supported mirrors are lighter (3.36 kg), achieving 87% lighter weight than the solid-state mirrors and 24% less mass than the three-point support. In the X, Y, Z The RMS value of surface shape accuracy under 1 g gravity load in the triaxial direction was 2.2, 2.1 and 7.5 nm, respectively, which was better than that of the three-point support. The RMS value of surface area accuracy under a uniform temperature rise load of 4 ℃ was 2.8 nm, Much less than the design requirement RMS≤12 nm; the first order natural frequency of the mirror assembly is 135 Hz and the maximum rigid body displacement of the mirror under gravity is 3.96 μm. The design not only greatly reduces the quality of the reflector and its components, but also ensures the surface accuracy of the reflector and the dynamic and static rigidity of the components to meet the design requirements, and provides a lightweight optimization design of the same type of space reflector Kind of new ideas.