A new method for evaluation of the pitch deviation of a linear scale grating by an optical angle sensor
A new method for evaluation of the pitch deviation of a linear scale grating by an optical angle sensor
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DOI：
10.1016/j.precisioneng.2020.09.008
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发表时间：
2021-01-01
影响因子：
3.6
通讯作者：
Gao, Wei
中科院分区：
文献类型：
--
作者：
Quan, Lue;Shimizu, Yuki;Gao, Wei
提出了一种基于激光自准直的光学角度传感器测量光栅尺螺距偏差的新方法。在该方法中，通过检测一阶衍射光束衍射角的变化来评估光栅尺螺距偏差，而衍射角的变化与光栅尺螺距偏差的变化相关。光学角度传感器单元被设计为同时测量正、负一阶衍射光束的衍射角，这样通过差分运算就可以消除线性光栅尺扫描时线性滑台的形状误差和滚动误差运动的影响。基于激光自准直的光学角度传感器单元是新设计和开发的，并且通过所开发的装置对来自商用干涉扫描式线性编码器的线性光栅尺的螺距偏差进行了评估，以在实验中验证所提方法的可行性。通过差分运算得到的光栅尺形状误差也与商用斐索干涉仪所评估的结果进行了比较。此外，基于《测量不确定度表示指南》（GUM）对所提出的螺距偏差测量进行了不确定度分析，从理论上验证了所提方法的可行性。
A new method for measurement of the pitch deviation of a scale grating by an optical angle sensor based on the laser autocollimation is proposed. In the proposed method, the scale pitch deviation is evaluated through detecting the change in the angles of diffraction of the first-order diffracted beams, which is associated with the change in the scale pitch deviation. The optical angle sensor unit is designed to measure the angles of diffraction of both the positive and negative first-order diffracted beams simultaneously so that the influences of the scale form error and the roll error motion of the linear slide for the scanning of a linear scale can be canceled through the differential operation. The optical angle sensor unit based on the laser autocollimation is newly designed and developed, and the pitch deviation of a linear scale from a commercial interferential scanning-type linear encoder is evaluated by the developed setup to verify the feasibility of the proposed method in experiments. The scale form error obtained through the differential operation is also compared with the one evaluated by a commercial Fizeau interferometer. Furthermore, the uncertainty analysis on the proposed pitch deviation measurement is carried out based on GUM to theoretically verify the feasibility of the proposed method.