高精度光电编码器莫尔条纹信号质量分析方法  

Method of analysis based on quality of Morié fringe signals for high precision optical encoder

作　　者：左洋[1,2] 龙科慧[1] 刘兵[1,2] 周磊[1] 刘金国[1] 乔克[1] 

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：《红外与激光工程》2015年第1期260-265,共6页Infrared and Laser Engineering

基　　金：国家自然科学基金(61108066)

摘　　要：针对莫尔条纹信号质量对高精度编码器细分误差的影响,提出了基于离散傅里叶变换分析莫尔条纹信号质量的方法。该方法利用信号重构和傅里叶变换算法得到信号参数,真实地反应了莫尔条纹信号质量,提高了细分误差测量的准确性。编码器转动时,采集相位差为π/2的两路精码正弦光电信号,通过对采样信号的重构得到信号波形,利用离散傅里叶变换算法分析重构波形,求解信号的直流分量、幅值、相位和谐波分量等各项参数。最后,根据信号参数与细分误差的关系得到光电编码器的细分误差值,并进行了实验验证。实验结果表明,对某24位绝对式光电轴角编码器细分误差进行测量,细分误差的峰值为+0.48'和-0.21'。相对于传统的细分误差测量方法,此方法测量速度快,测量精度高,适用于工作现场。Aiming at the affection of Morie fringe signal quality for high- precision encoder interpolation error,a method of analysis based on quality of morie fringe signals for high precision optical encoder was presented. The signal parameters were obtained with using signal reconstruction and Fourier transform algorithm, which reflects the real Morie signal quality. The accuracy of interpolation error of measurement was improved. While the encoder is motion, the data acquisition card samplings two photoelectric signal with a phase difference of π/2. The signal waveform was got by reconstruction algorithm of sampling the signal. Through the discrete Fourier transform algorithm analyzing reconstruction waveform, the parameters like DC component, amplitude, phase, and harmonic component were solved. Finally, dynamic interpolation error is obtained based on relationship between the signal parameters and interpolation error by experimental verification. Experimental results show that, the＆amp;nbsp;interpolation error of a 24- bit absolute rotary optical encoder was measured . Interpolation extreme errors are＋0.48＂and - 0.21＂. Compared with traditional method of interpolation error measurement, this method measures quickly . It is applicable to real- time detection of encoder dynamic interpolation error at the actual work site .

关 键 词：光电编码器 莫尔条纹 离散傅里叶变换 细分误差 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]