大型矩形准直镜柔性支撑系统的多目标优化设计和稳定性分析

针对极大望远镜矩形准直镜设计了一种新型柔性支撑系统，即由6根空心圆柱杆为支撑主体的侧面支撑结构。利用多目标优化算法对柔性支撑系统的结构参数和位置参数进行优化设计，并对优化后的柔性支撑系统进行稳定性研究。优化后的准直镜柔性支撑系统在自重条件下镜面最大PV值为168.23 nm，RMS值为30.306 nm，质量为229.21 kg，满足设计要求。当环境温度变化范围在20 ℃～23.7 ℃内，不会对准直镜性能产生影响；此外，地面随机振动不会影响准直镜工作性能和破坏支撑结构。研究结果表明:准直镜柔性支撑机构的多目标优化设计全面考虑了准直镜柔性机构形状参数、机构安全可靠性和光学面形形变等多学科之间耦合问题，设计者可按需选择全局范围内最满意的最优解，这将大幅度降低开发成本和周期。

Multi-objective optimization design and stability analysis of flexible support system for large rectangular collimator mirror

A new flexible support system was designed for the rectangular collimator of extremely large telescope. The system was a side support structure supported by six hollow cylindrical bars. The structural parameters and position parameters of flexible support system were optimized by multi-objective optimization algorithm, and the stability of the optimized flexible support system was also studied. The optimized flexible support system for collimator had a maximum peak valley (PV) value of 168.23 nm, root-mean-square (RMS) value of 30.306 nm and a weight of 229.21 kg under the influence of gravity only, which satisfied the design requirements. When the ambient temperature changed within 20℃~23.7℃, the mirror performance would not be affected; besides, random ground vibration would not affect the performance of the collimator and destroy the support structure. The results show that the multi-objective optimization design of the flexible support mechanism for collimating mirror comprehensively considers the coupling problems between the shape parameters of the flexible support mechanism for collimating mirror, the safety and reliability of the mechanism and the deformation of the optical surface, etc. Designers can choose the most satisfactory solution on the global scale as needed, which will greatly reduce the development cost and cycle time.