圆光栅测角系统示值误差分析与补偿

Indication error analysis and compensation of circular grating angle measurement system

首先针对引起圆光栅测角系统示值误差的主要来源(光栅盘的偏心及倾斜)进行理论研究,同时提出光栅盘与转动轴的同轴安装方法;利用中国计量科学研究院的全圆连续角度标准装置(测量不确定度为0.05″)对待测圆光栅测角系统直接进行溯源性测试,避免了圆光栅安装过程和间接溯源性测试(多面棱体和光电自准直仪配合校准)过程中引入的仪器误差;其次利用谐波理论分析偏心和倾斜以及其它阶次误差在频谱中的分布;最后针对安装偏心和倾斜造成的误差,进行谐波补偿。实验结果表明,测角系统的示值误差从补偿前的100″减小到了10″,有效消除了光栅盘安装偏心、倾斜造成的稳定可复现的误差谐波成分。

Firstly the indication error main source of the angle measurement system of circular grating(eccentricity and tilt of grating disk)is studied theoretically,and the coaxial installation method of grating disk and rotating shaft is proposed.The continuous full circle angle standard device in NIM(the measurement uncertainty is 0.05″)is used to directly perform traceability test of the measured circular grating angle measuring system,which avoids the instrument errors introduced in the installation process of the circular grating and the indirect traceability test process(the calibration using combined polyhedral prism and photoelectric autocollimator).Secondly,the distribution of eccentricity,tilt and other order errors in the spectrum is analyzed using harmonic theory.Finally,the harmonic compensation is carried out for the errors caused by installation eccentricity and tilt.The experiment results show that the angle indication error of the angle measurement system is reduced from 100"before compensation to 10"after compensation,which effectively eliminates the stable and repeatable error harmonic components caused by the installation eccentricity and tilt of grating disk.