大口径望远镜消旋K镜旋转策略及准直技术研究

Rotating Strategy and Alignment Technology of K Mirror in Large Aperture Telescope

摘要: 针对2m地平式望远镜像方视场旋转问题设计了消旋K镜装置。首先，根据K镜系统的光学传递特性，推导K镜消旋数学矩阵模型；其次，利用光线追迹方法，拟合了望远镜入瞳坐标与coude焦点坐标的转换关系，分析入射光经过coude光路后的视场旋转与望远镜方位轴、俯仰轴旋转的换算规律，从而计算得出望远镜消旋K镜的初始零位及旋转规则；然后，针对K镜的准直性问题，通过对其旋转过程K轴与主光路偏离误差周期性变化特性的分析，设计了基于帕斯卡窝线理论的K镜准直装调策略，将复杂的准直装调问题转化为数学方程参数修正问题，并建立K镜准直精度与帕斯卡窝线方程中关键参数的计算模型。最后，开展了K镜准直装调实验，在准直装调过程中反复修正模型中关键参数，使误差曲线不断趋近最优值。实验结果验证了本文所做研究的有效性及正确性。

Abstract: Aiming at the image field rotation of 2 m Alt-az telescope, the K mirror is designed. First, according to optical transfer characteristic of K mirror system, the mathematical matrix model is calculated. The second, based on the method of ray tracing, the transformation relation between incident light coordinate and coude focus coordinate is fitted. The image field rotation of incident light through the light path of coude is analyzed, and the conversion regularity of the image field rotation involving the azimuth axis and pitching axis of telescope is deduced, thus the initial zero and rotation rules of K mirror are obtained. Then, in allusion to the alignment accuracy of K mirror, through the analysis of the periodic variation characteristics of alignment error in the rotation period of K mirror, the alignment adjustment strategy of K mirror is designed basing on the theory of Pascal Spiral, the complex problem of alignment adjustable is transformed into the parameter correction of mathematical equations, and the calculation model of the alignment accuracy and the key parameters in Pascal Spiral equation is established. Finally, the alignment adjustable experiment is carried out. The key parameters in the model are modified repeatedly during the experiment. The alignment error curve keeps getting closer and closer to the optimal value. The correctness and effectiveness of the research is verified from the experimental results.