第1期
第22卷 2014年1月
文章编号1004-924X(2014)01-0213-07
光学精密工程
Optics and Precision Engineering
Vol.22No.1
Jan.2014
莫尔条纹光电信号正交性偏差的实时补偿
高旭1.2，万秋华1*，赵长海"，孙莹"，杨守旺1
（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）
摘要：为了提高光电轴角编码器的精度，提出了一种实时补偿莫尔条纹光电信号正交性偏差的方法。利用希尔伯特变换原理，构造了同频光电信号正交性偏差的动态测量算法。根据莫尔条纹光电信号的数学模型，需示了由正交性偏差引起的细分误差的空间分布特征并建立角度补偿模型。鉴于编码器的实际工作特点，采用同步处理方式，在补偿光电信号的同时动态更新了角度代码补偿查找表；通过细分查找表的切换，实现信号正交性偏差的实时补偿。采用该方法对存在约
该方法可实际应用于编码器系统，能够提高编码器的细分精度、环境适应性和可需性。关键调：光电轴角编码器，英尔条纹；正交性偏差；希尔伯特变换；实时补偿
中图分类号：TP212.14;O436.1
文献标识码：A
doi;10, 3788/OPE, 20142201, 0213
Real-timecompensationof orthogonalitydeviationforMoirefringe
photoelectric signal
GAO Xul.?, WAN Qiu-hua'', ZHAO Chang-hai', SUN Ying', YANG Shou-wang
(l.ChangchunInstitute of Optics,FineMechanics and Physics,ChineseAcademy of Sciences,
Changchun130033,China;
2.University of ChineseAcademyof Sciences，Beijing100049,China)
*Correspondingauthor，E-mail:wanqh@ciomp.ac.cn
Abstract: A method to compensate the orthogonality deviation of the Moire fringe photoelectric signa was proposed to improve the accuracy of a photoelectric rotary encoder. Based on Hilbert transform theory, a dynamic measurement algorithm for the orthogonality deviation of same frequency photoe lectric signal was constructed. In the light of the mathematical model for Moire fringe photoelectric signal, the influence of orthogonality deviation on subdivision precision was analyzed and an angle compensation model was set up. According to the working principle of the encoder, a synchronous processing mode was adopted to compensate the photoelectric signal and update dynamically the look up table for angle codes simultaneously; by the switching of subdivision lookup table, the orthogonali-ty deviation for the photoelectric signal was compensated in real time, Finally, a 23-bit photoelectric encoder with 18° orthogonality deviation was compensated using this method. Experimental results show that the peak value of subdivision error of the encoder has reduced from 4. 79" to 1. 26 " after
收稿日期：2013-09-16；修订日期：2013-10-25. 基金项目：中国科学院知识创新工程资助项目