Design and Implementation of a Non-Contact Magnetic Sensing and Signal Processing System for High-Precision Robot Joint Encoders
DOI:
https://doi.org/10.71204/fef1s997Keywords:
Non-Contact Magnetic Sensing, Robot Joint Encoder, Signal Processing, Adaptive Error Compensation, TMR Sensor, Robotic Motion ControlAbstract
Robot joint encoders are critical sensing components in industrial robots, where positioning accuracy, dynamic response, and environmental adaptability directly affect motion-control performance and operational reliability. However, conventional encoder technologies still face challenges related to signal instability under harsh industrial conditions, insufficient high-speed response capability, and limited long-term reliability. To address these issues, this paper presents the design and implementation of a non-contact magnetic sensing and signal-processing system for high-precision robot joint encoders. The proposed system integrates incremental magnetic grid design, tunnel magnetoresistance (TMR) sensing technology, adaptive signal conditioning, multi-dimensional error compensation, and high-speed signal-processing algorithms into a unified encoder framework. A dual-reading-head magnetic grid structure and dynamic gain compensation mechanism are introduced to improve signal stability under vibration, temperature variation, oil contamination, and electromagnetic interference conditions. In addition, adaptive filtering and real-time interpolation algorithms are employed to enhance dynamic response capability and suppress nonlinear measurement errors during high-speed robot motion. The developed encoder system supports multiple industrial communication interfaces, including RS422, SSI, and CANopen, enabling flexible integration with industrial robot control systems. Experimental results demonstrate that the proposed encoder achieves repeatability accuracy within ±1 μm and a frequency response of 8000 kHz while maintaining stable operation under harsh industrial environments. Engineering deployment in industrial robots and precision manufacturing equipment further verifies the robustness, reliability, and practical applicability of the proposed system. The research provides an effective technical solution for high-precision robotic motion sensing and intelligent industrial measurement systems.
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Copyright (c) 2026 Chaohui Zhang, Lujie Ren, Jianming Mao, Haijun Lei, Dengcheng Lu, Shishui Zhou (Author)
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