基于动态误差的柔性支撑优化设计

Optimization design of flexible supports based on dynamic error

星-地激光通信具有通信距离远、传输信道复杂等特点,为建立稳定可靠的星-地激光通信链路,需要建立大口径的地面站。着重研究了地面站中500mm大口径主镜柔性支撑的点位分布及结构尺寸。让主镜组件既满足刚度需求,也具有柔度缓解其自身动态误差。在Isight平台建立光机热耦合的优化流程。运用Zernike多项式拟合面形得到精准的镜面RMS值;并以此为优化目标,获取柔性支撑点位的最优解及柔性杆尺寸参数的最优解。经过优化,主镜组件可适应温度范围扩大了约30℃;在俯仰角度变化下,主镜RMS值下降约2nm。对设备进行了相关试验,主镜面形均满足指标要求小于0.08λ。

The satellite-Earth laser communication has the characteristics of long communication distance and complex transmission channel.In order to establish a stable and reliable satellite-Earth laser communication link,it is necessary to build a large-aperture ground station.The point position distribution and structure size of the flexible support of the 500mm large aperture primary mirror in the ground station are studied.This allows the primary mirror assembly not only to meet the stiffness requirements,but also to have flexibility to mitigate its own dynamic errors.The optimization process of optical,mechanical and thermal coupling is established on Isight platform.The accurate mirror RMS value is obtained by fitting the surface shape with Zernike polynomial.Taking the RMS value as the optimization objective,the optimal solution of the flexible support point position and the optimal solution of the dimension parameter of the flexible rod are obtained.After the optimization,the temperature range of the primary mirror component is extended by about 30℃ and when the pitch Angle changes,the RMS value of the primary mirror decreases by about 2nm.The main mirror shape meets the requirement of index less than 0.08λ.