Du Yongbin, Yuan Feng, Jiang Zongze, Li Kai, Yang Shuiwang, Zhang Qingbai, Zhang Yinghui, Zhao Hongliang, Li Zhaorui, Wang Shunli
School of Instrumentation Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Beijing Zhenxing Institute of Metrology and Measurement, Beijing 100074, China.
Sensors (Basel). 2021 Nov 16;21(22):7599. doi: 10.3390/s21227599.
A circular grating angle encoder is a key component in the dynamic torque calibration system. To improve the accuracy of an angle measurement, in this paper, the source of the angle measurement error of the circular grating is analyzed; an eccentricity error model and an inclination error model are proposed, respectively; further, these two models are combined to establish a total error model. Through the simulation study with the models, the conditions, in which the eccentricity error or inclination error can be ignored, are discussed. The calibration and compensation methods of the angle measurement error are given, and a progressive error compensation function which integrates the first harmonic fitting and the second harmonic fitting is obtained. An experiment is performed to verify the proposed calibration and compensation methods. The peak-to-peak value of the compensated angle measurement error of the single reading head can be reduced by about 93.76%, which approximates to the error of the mean value of the double reading heads. The experimental results show that the error calibration and compensation method based on the proposed error model can effectively compensate the angle measurement error of the circular grating with a single reading head, and obtain a high-precision measurement angle.
圆光栅角度编码器是动态扭矩校准系统中的关键部件。为提高角度测量精度，本文分析了圆光栅角度测量误差的来源，分别建立了偏心误差模型和倾斜误差模型；进而将这两种模型相结合，建立了总误差模型。通过对模型的仿真研究，讨论了可忽略偏心误差或倾斜误差的条件。给出了角度测量误差的校准和补偿方法，得到了一种融合一次谐波拟合和二次谐波拟合的递进式误差补偿函数。进行了实验验证所提出的校准和补偿方法。单读数头补偿后的角度测量误差峰峰值可降低约93.76%，接近双读数头平均值的误差。实验结果表明，基于所提出误差模型的误差校准和补偿方法能够有效补偿单读数头圆光栅的角度测量误差，获得高精度的测量角度。
