伴随空间光学载荷口径增大, “天地力学环境不一致”导致光学系统在轨像质严重下降, 需要地面装调测试过程卸载重力。但定量的卸载点布局分析、优化方法有待完善。首先研究了大口径光学载荷1 g重力下变形机理, 分别基于位置闭环和受力闭环, 建立优化卸载点布局的数学模型, 并通过协同仿真获得卸载点布局优化结果。利用仿真卸载实验验证不同卸载参数下, 光学载荷的实际卸载效果。基于位置闭环的卸载方法将高敏感光学组件的位恣平均变化量由370 μm、36″改善至72.9 μm、0.3″, 而基于受力闭环卸载方法的最大相对偏差约为7.4%。基于位置闭环的卸载分析方法可获得更接近0 g的卸载效果, 但误差敏度极高, 不易工程实现。基于受力闭环的卸载方法总卸载率约75%, 对卸载残差的敏感度相对较低, 可满足半物理仿真实验对力学环境的模拟需求。

Following the increase in the aperture of space optical telescopes, the inconsistency in space and ground mechanical environment results in serious degradation of the system image quality in orbit. Gravity needs to be compensated during the alignment and test procedure of a space telescope. However, quantitative analysis and optimization methods for unloading the point coordinate have not been completely developed. First, the deformation mechanism of a large-aperture telescope under 1g gravity was studied. According to the separate closed-loop location and closed-loop mass, a mathematical algorithm was developed to optimize the position of the unloading points. By performing co-simulation, we were able to optimize the coordinates. Subsequently, simulation experiments were performed to verify the actual effect of the telescope model under different unloading parameters. The closed-loop location analysis method improves the displacement of the highly sensitive optical components from 370 μm, 36″ to 72.9 μm, 0.3″. The maximum relative deviation of the closed-loop mass method from the set value is approximately 74%. The closed-loop location gravity-compensation method can achieve a value closer to 0 g. However, its error sensitivity is high, and realizing the engineering results is difficult. The total unloading rate is approximately 75% based on the closed-loop mass gravity-compensation model, and the sensitivity is low. This model can satisfy the demand for mechanical environment of semi-physical simulation experiments using gravity unloading.