为提高圆光栅编码器测角精度、满足角秒甚至亚角秒级的精度测量需求,分析了影响其角度测量精度的误差来源,针对性地提出了多读数头读数平均法的补偿方法,进而控制误差源。根据圆光栅测角原理,分析了光栅系统刻化误差、读数头细分误差、光栅安装偏心误差、安装形变误差、轴晃误差等误差来源,从频域的角度分析了各个误差的频谱,根据误差源分析,可采用多读数头读数平均法的补偿方法。实验结果表明,在偏心误差约为15″、光栅形变误差约为1.5″的条件下,采用4读数头平均法实测的测角误差优于0.8″,大幅提高了圆光栅测角精度。

To improve the angle measurement accuracy of a circular grating encoder and meet the accuracy measurement requirements of arc-second and even sub-arc-second levels, this paper analyzes the error sources that affect the accuracy of the angle measurement and proposes the compensation method of the multi-reading head reading averaging method to control the error sources. According to the principle of the circular grating angle measurement, the error sources, such as the grating system engraving error, reading head interpolation error, grating installation eccentricity error, installation deformation error, and shaft shaking error, are analyzed, and each error spectrum is analyzed from the perspective of frequency domain. According to the error source analysis, the compensation method of multi-reading head reading averaging method can be used. Experimental results show that under the condition that the eccentricity error is about 15″ and the grating deformation error is about 1.5″, the measured angle error is better than 0.8″ by the four-reading head averaging method, which greatly improves the angular measurement accuracy of the circular grating.