扭转角测量系统中焦距误差分析  

Analysis of focal length error in torsion angle measurement system

作　　者：杨文昌 王志乾[1] 宋卓达 杜闻 李勤文 YANG Wenchang;WANG Zhiqian;SONG Zhuoda;DU Wen;LI Qinwen(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《应用光学》2020年第3期477-481,共5页Journal of Applied Optics

基　　金：吉林省重点科技攻关项目(20170204050GX,20190302086GX)。

摘　　要：针对莫尔条纹测量扭转变形方案,分析了双光栅在光学系统存在焦距误差时对扭转角测量精度的影响。通过在传统的莫尔条纹测量扭转角理论公式的基础上引入焦距对于光栅像的缩放效应,推导出含有焦距因子的扭转角测量模型。由模型可知,随着光学系统焦距差异的增大,对应的扭转角也会随之发生较大变化。特别当光栅夹角在小角度范围(1°~3°)内变化时尤为明显,最终影响到扭转变形的测量精度。在设计的实验中,利用2个已知焦距的光学系统,通过采集莫尔条纹图像进行扭转角精度分析,验证了该文提出的理论。Aiming at the torsional deformation scheme of Moiréfringe measurement,the influence of doublegrating on the measurement accuracy of torsion angle in the optical system with focal length error was analyzed.Based on the traditional Moiréfringe measurement torsion angle theory formula,the scaling effect of focal length on the grating image was introduced,and the torsion angle measurement model with focal length factor was derived.According to the derived model,as the focal length difference of the optical system increases,the corresponding torsion angle also changes greatly.Especially the change at small angles(1°~3°)is particularly obvious,which ultimately affectes the measurement accuracy of the torsional deformation.In the designed experiment,the theory proposed was verified by using two optical systems with known focal lengths to analyze the torsion angle accuracy by collecting the Moiréfringe image.

关 键 词：扭转变形 莫尔条纹 光学系统 焦距 

分 类 号：TN206[电子电信—物理电子学] TH712[机械工程—测试计量技术及仪器]