Measurement Error Suppression of Circular Grating Angle Encoders Based on Multi-sensor Data Fusion and Augmentation Compensation

doi:10.3901/JME.260271

Abstract

Abstract: The formation mechanism of angular measurement error of multi-sensor angle encoder is unclear, and the calibrated data of angle encoder is insufficient for high-precision error compensation. Therefore, the equal amplitude method is used to study the influence of installation error on the angular measurement error, based on the principle of harmonic error suppression for multi-sensor encoder. The influence of grating eccentricity, grating tilt, and shaft system vibration on harmonic error suppression effect is revealed. It is found that the installation errors result in degradation of the suppression performance of higher-order harmonics. The open grating and precision rotary axis were used to build an encoder accuracy test platform with multiple sensors evenly distributed along the circumferential direction. The angular measurement error of an encoder with a systematic error of ±2.78″ was improve to ±0.5″ through the uniform distribution of 8 sensors. In order to suppress the residual system error, the error compensation performance of the segmented linear interpolation, cubic spline interpolation and harmonic compensation algorithms are comprehensively compared. It is found that segmented linear interpolation and cubic spline interpolation are more effective. A data augmentation and integration method using group calibration is proposed based on the harmonic characteristics of the angular measurement error of circular grating. The results indicate that the segmented linear interpolation algorithm has the best compensating precision. The angular measurement error at the non-calibrated points was finally decreased to ±0.4″ for the angle encoder with 8 sensors evenly distributed.

Key words: circular grating, angle encoder, error compensation, angular measurement error, installation error

CLC Number:

TH712

LI Changsheng, DING Jianjun, JIN Yusheng, LIU Yangpeng, WANG Zhenyi, LIU Xindong, JIANG Zhuangde. Measurement Error Suppression of Circular Grating Angle Encoders Based on Multi-sensor Data Fusion and Augmentation Compensation[J]. Journal of Mechanical Engineering, 2026, 62(10): 23-40.

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URL: http://www.cjmenet.com.cn/EN/10.3901/JME.260271

http://www.cjmenet.com.cn/EN/Y2026/V62/I10/23

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