在地面环境检测的空间反射镜面形主要是镜面加工残差和重力支撑变形等耦合的结果.为实现1.2 m轻量化空间反射镜的重力支撑变形分离, 通过测量镜面在等梯度支撑力下的面形, 由镜面力学响应得到镜面畸变和支撑力变化的关系, 以此作为界定有限元分析结果和优化有限元模型的依据.将由修正模型得到的重力支撑面形畸变从反射镜面形检测结果中移除, 即可得到反射镜加工残差.研究表明, 修正后的模型对100 N支撑力变化引起的面形畸变与实测结果误差≤0.001λ, 面形检测为1/30λ的空间反射镜, 其无重力和支撑影响的加工残差优于1/40λ.该结果不仅能指导反射镜面形的高精度抛光, 还可提高最终系统装调精度.

The test result of space mirror figure in the ground environment is mainly composed of the surface processing residual and the distortion caused by gravity and support. In order to realize the gravity-support distortion separation of the 1.2 m lightweight space reflector, by testing mirror with equal gradient support forces, the relationship between mirror figure distortion and the change of support forces is obtained from the mirror mechanical response, which can be used as a basis for judging the result of finite element simulation and optimizing finite element model. After removing the mirror figure distortion calculated with the corrected model from the mirror test result, the surface processing residual is obtained. The research shows that the differece of mirror distortion change caused by 100 N supporting force change between the result calculated with the corrected model and the test result is ≤0.001λ, without the effects of gravity and support, the surface processing residual of space mirror with test result rms 1/30λ is better than 1/40λ. This result can not only guide the high precision surface polishing, but also improving the alignment precision of final system.