1 m望远镜俯仰轴系精度检测误差的修正

摘要

针对1 m望远镜俯仰轴系检测精度未达到系统指标,而系统运转性能优异的问题,研究了系统可能存在的可消除误差项.通过对影响1 m望远镜俯仰轴系精度的主要因素-中间体(四通)的有限元分析和运算,得出了四通在不同俯仰角度的变形曲线,并与实际检测结果进行对比,找出两者的相同特征并进行了补偿.按此方法使得望远镜俯仰轴系晃动误差PV值从2.42″降到0.95″,RMS值从0.7″降到了0.3″,提高了系统精度模型的准确性.推导出了设计过程中的检测指标,为更大口径望远镜轴系的设计和检测提供了理论依据.%Altitude axis precision is important to the performance of a large aperture telescope.At practice,the tested result can not reach the system requirement,but the performance is well enough,so there must be error factors caused by centerpart deformation that can be eliminated in this system.To improve the accuracy of an altitude axis precision model,the centerpart,a main part effeting altitude axis precision is analyzed by the Finite Element Method (FEM),and then the curve of altitude axis max deformation versus pitch angle is obtained.After analyzing the influence of deformation on the axis precision,a modification method is proposed,which uses a compensation method to add the tested results to the calculated results.By this way,the PV error and the RMS error of axis shake are reduced from 2.42" to 0.95" and from 0.7"to 0.3",respectively.The method can improve the accuracy of the system precision model,and can provide theoratical basis for design and test of an even larger telescope.