基于误差分析与改进CORDIC算法的反射式光栅位移测量方法  

A reflective grating displacement measurement method based on error analysis and the improved CORDIC algorithm

作　　者：李润泽 王涛 牛群峰[1] 王莉[1] 林树翔 Li Runze;Wang Tao;Niu Qunfeng;Wang Li;Lin Shuxiang(College of Electrical Engineering,Henan University of Technology,Zhengzhou 450000,China;Sanmenxia Zhongyuan Measuring Instrument Co.,Ltd.,Sanmenxia 472000,China)

机构地区：[1]河南工业大学电气工程学院,郑州450000 [2]三门峡中原量仪股份有限公司,三门峡472000

出　　处：《仪器仪表学报》2024年第11期215-223,共9页Chinese Journal of Scientific Instrument

基　　金：河南省科技攻关项目(242102220094)资助。

摘　　要：针对现有反射式光栅和读数头在小体积时无法设置更多的栅线对数进一步提升稳定性,导致精度无法得到提升等问题,提出了一种提高反射式光栅位移测量精度的方法。该方法通过对影响光栅莫尔信号的直流、幅值、正交性偏差3个主要因素进行误差分析来实时误差修正光栅莫尔信号质量,并且采用反正切细分法对修正后的光栅莫尔信号进行插值细分得出测量结果,同时改进了正交性误差修正和反正切细分中用到的CORDIC算法。实验结果表明,细分误差由修正前的45″减小到了经过修正后的6″,验证了系统的可重复性,正、反向位移的一致性和滞回性,在相同的栅线对数情况下,测量精度达到了±1μm,显著优于商用光栅位移传感器。Aiming at the problem that the existing reflective grating and reading head can not set more grid lines to further improve the stability and accuracy when the volume is small,a method to improve the displacement measurement accuracy of the reflective grating was proposed.The method corrects the grating Moire signal quality by analyzing the error of three main factors which affect the grating Moire signal DC,amplitude and orthogonality deviation,and uses arctangent subdivision method to interpolate and subdivide the corrected grating Moire signal to obtain the measurement result.At the same time,it improves the CORDIC algorithm used in the orthogonality error correction and arctangent subdivision.Experimental results show that the subdivision error is reduced from 45″before correction to 6″after correction,which verifies the repeatability of the system,the consistency and hysteresis of the forward and reverse displacement,and the measurement accuracy reaches±1μm under the same grid logarithm,which is significantly better than the commercial grating displacement sensor.To address the problem that the existing reflective grating and reading head cannot set more grid lines to further improve the stability and accuracy when the volume is small,a method for improving the displacement measurement accuracy of the reflective grating is proposed.The method corrects the grating Moire signal quality by analyzing the error of three main factors that affect the grating Moire signal,including DC,amplitude,and orthogonality deviation.The arctangent subdivision method is used to interpolate and subdivide the corrected grating Moire signal to obtain the measurement result.Meanwhile,it improves the CORDIC algorithm used in the orthogonality error correction and arctangent subdivision.Experimental results show that the subdivision error is reduced from 45″before correction to 6″after correction,which verifies the repeatability of the system,the consistency and hysteresis of the forward and reverse displacement.The measurem

关 键 词：反射式光栅 实时误差修正 莫尔信号 CORDIC算法 

分 类 号：TH711[机械工程—测试计量技术及仪器]