多通道光栅莫尔信号实时细分与等分平均技术研究  

Study on real-time subdivision and equal division averaging technology for multi-channel grating moir signals

作　　者：李强[1,2] 刘宏伟 何韬[1,2] 杜坤 夏仰球 Li Qiang;Liu Hongwei;He Tao;Du Kun;Xia Yangqiu(Institute of Machinery Manufacturing Technology CAEP,Mianyang 621900,China;National Machine Tool Production Quality Supervision Testing Center(Sichuan),Chengdu 610200,China)

机构地区：[1]中国工程物理研究院机械制造工艺研究所,绵阳621900 [2]国家机床产品质量检验检测中心(四川),成都610200

出　　处：《仪器仪表学报》2024年第9期189-196,共8页Chinese Journal of Scientific Instrument

基　　金：国防科工局技术基础项目(J0133-2224-FJC)资助。

摘　　要：圆光栅受刻线误差、安装偏心等多种因素的共同影响,其定位精度无法直接满足高精度测角系统的需求。多读数头等分平均方法可以实现圆光栅精度的自校准,是提高测角系统精度的有效方法。然而,商业伺服控制系统通常不支持多路读数头信号实时接入同一路伺服轴,这造成了等分平均方法的在线应用存在困难。本文针对多通道光栅莫尔信号的采样、误差补偿、实时细分和等分平均进行研究,基于FPGA平台实现了多读数头实时处理系统的研制,并在测角转台开展了应用验证。设计了细分值稳定性、控制分辨率、角定位精度和细分误差实验,验证了多读数头实时处理系统的性能。所设计的多读数头处理系统,在测角转台上可以满足0.005″的控制分辨率需求,取得了0.58″定位精度和0.06″重复定位精度等测试结果。Circular gratings are susceptible to factors such as engraving errors and installation eccentricity,preventing them from directly meeting the positioning accuracy requirements of high-precision angle measurement systems.Averaging data from multiple read heads can effectively self-calibrate the accuracy of circular gratings,thereby enhancing the precision of angle measurement systems.However,commercial servo control systems typically do not support real-time access to multi-read head signals on the same servo axis,making the online application of the equal division averaging method challenging.This paper explores the sampling,error compensation,real-time subdivision,and equal division averaging of multi-channel grating moir signals.A real-time processing system for multiple read heads was developed using an FPGA platform and applied to an angle measurement turntable.Experiments were designed to evaluate the stability of subdivision values,control resolution,angular positioning accuracy,and subdivision error,verifying the performance of the real-time multi-read head processing system.The system successfully enabled the online application of the equal division averaging method for multiple read heads,meeting the control resolution requirement of 0.005″on a rotating test bench for angle measurement,achieving a positioning accuracy of 0.58″,and obtaining a repeatability of 0.06″in positioning accuracy.

关 键 词：光栅莫尔信号 多读数头 等分平均方法 误差补偿 FPGA 转台 

分 类 号：TH712[机械工程—测试计量技术及仪器]