通过分析光学系统结构参数变化对像差的影响, 提出通过优化各光学表面的曲率进行光焦度合理分配来减小各表面产生的初级像差, 从而实现降低各加工装调公差灵敏度的方法.利用该方法优化了一个小像差相互补偿的焦距为25 mm, 全视场角为26°, 入瞳孔径为18 mm, 光谱范围为500 ~800 nm的大视场纳型星敏感器光学系统, 系统全长40 mm, 光学系统成像质量满足指标要求.与所设计的大像差相互补偿光学系统进行了公差灵敏度对比分析, 结果表明：光焦度合理分配后的光学系统, 第5片透镜的厚度公差对均方根弥散斑半径的影响从3.75 μm降低到0.17 μm; 第5和第6元件间隔公差对均方根弥散斑半径的影响也分别从4.36 μm和4.74 μm降低到0.25 μm和0.18 μm.蒙特卡罗分析表明, 均方根弥散斑半径小于7.59 μm的概率从23%增加到了80%.实验测试结果表明, 星敏感器在全视场范围内, 能量集中度在Φ17 μm范围内优于80%, 满足星敏感器的指标要求.

By analyzing the influence of the optical system structural parameters on aberrations, a method was proposed to reduce the primary aberrations of each optical surface by optimizing the curvature to make a reasonable power distribution, which could reduce the processing and adjustment tolerance sensitivities. Using this method, a nano-star sensor optical system with a focal length of 25 mm, a full field of view of 26°, entrance pupil diameter of 18 mm and spectrum range of 500~800 nm was designed, which was a small aberration compensation system. The whole length of the system was 40 mm. The imaging quality of the optical system met the requirements. Tolerance sensitivity analysis was carried out for two optical systems. The results show that the influence of the thickness tolerance of the fifth lens on the Root Mean Square (RMS) spot radius decreases from 3.75 μm to 0.17 μm in the reasonable power distribution optical system; and the influence of the fifth and sixth element spacing tolerances on the RMS spot radius decreases from 4.36 μm and 4.74 μm to 0.25 μm and 0.18 μm, respectively. Monte Carlo analysis shows that the probability of the RMS spot radius of less than 7.59 μm is increased from 23% to 80%. The experimental results show that in the full field of view the energy concentration of the star sensor is better than 80% in the range of Φ17 μm, which meets the requirements.