为了提高空间相机在不同温度条件下的成像质量,本文建立了空间相机光-机-热集成分析模型,以此模型为基础,对系统的温度-离焦特性进行研究,得到了相机温度调焦曲线,并开展了热光学试验.首先,分析了温度变化对光学系统的影响,特别是对最佳像面位置的影响,得到了相机离焦量与光学元件参数的关系;介绍了光机热集成分析的一般方法,即将热分析的温度场,经过映射,作为结构分析的边界条件,然后进行结构有限元的热弹性分析,通过对变形结果中光学元件曲率和刚体位移做拟合,得到敏感因素的温度-离焦敏感度矩阵;在此基础上得到了相机温度调焦曲线;最后,开展了相机热光学试验.试验结果表明,基于集成分析结果的温度调焦,空间相机在20℃±8℃内的最大误差小于0.1mm,基本满足相机在轨自动调焦的要求,并指出了进一步提高相机温度调焦精度的方法.%In order to improve the image quality of space camera in different temperature fields,a integrated analysis model of structure-thermal-optical performance (STOP) model was established.According to the model,the thermal-defocusing property of the system was studied and test,and focusing curve of camera temperature was obtained.Then,thermo-optical experiment was developed.Firstly,influence of temperature changes on optical system,especially influence on optimal image plane position,was analyzed to obtain relationship of defocusing amount and optical element parameters;then,general method of STOP integrated analysis was introduced.In this method,temperature field of thermal analysis was as boundary condition of structural analysis by mapping,and a thermo-elastic performance of finite element model was analyzed.Then,temperature-defocusing sensitivity matrix of sensitive factors was obtained by fitting the curvature of optical elements and rigid body displacement in deformation result.On the basis of above,Temperature-focusing curve of camera was obtained.Finally thermo-optical test of camera was carried out.Experimental result indicates that maximum error of temperature focusing based on integrated analysis result is less than 0.1 mm in 20 ℃ ± 8 ℃.The results basically satisfy camera requirements of on-orbit automatic focusing and method of further increasing camera precision of temperature focusing is pointed out.
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