为满足大口径反射镜在复杂空间环境下对高面形精度和热稳定性的要求, 针对某Φ 660 mm口径反射镜进行了轻量化研究。提出了一种采用经典理论公式创建反射镜初始结构, 结合灵敏度分析和参数优化进行综合设计的方法。首先构建了反射镜参数化模型, 采用灵敏度分析研究镜体结构参数对面形变化的影响规律, 找到对镜面面形RMS值灵敏度高的结构参数进行优化迭代。相比于传统反射镜结构设计方法,此方法缩小了优化设计空间, 节约了计算成本与时间, 能够在设计空间内全局寻优, 较快收敛于最优值。优化后反射镜在自重载荷工况下镜面面形PV值小于?姿/10, RMS值小于?姿/40(?姿=632.8 nm), 镜体质量为13.6 kg, 轻量化率达78.4%。镜体组件一阶频率为121 Hz, 满足反射镜动态刚度要求, 根据优化后的结果建立了反射镜的最佳结构模型, 并进行了投产制造。

In order to satisfy the stringent requirement for high surface shape accuracy and thermal stability of large-aperture mirrors in the complex space environment, a lightweight design for a Φ660 mm-diameter mirror was carried out. A method for creating the initial structure of the mirror using the classical theoretical formula, combining sensitivity analysis and parameter optimization for comprehensive design was proposed. Firstly, the parametric model was established, the influence law of the structure parameters of the mirror on the surface shape change was studied, and then iterations for the structural parameters with high sensitivity to the mirror surface RMS value were optimized through sensitivity analysis. Compared with the traditional mirror design model, this method reduced the optimization design space, saved computational cost and time, could globally optimize in the design space, and converged quickly to the optimal value. The mass of optimized mirror was 13.6 kg and the lightweight rate of the mirror reached 78.4%. The PV value of mirror surface accuracy was less than ?姿/10 and RMS value was less ?姿/40(λ=632.8 nm) under gravity load. The first-order frequency 121 Hz of the mirror assembly met the dynamic stiffness requirements of the mirror. Finally, based on the optimized results, the optimal mirror was put into production.