摘要
在工业监测与安全检测领域,微弱电流信号的非接触式高精度(TMR)检测是保障关键设备运行可靠性的核心技术。针对传统检测方法在高频存在的信号失真与噪声干扰以及检测精度过大的难题,研究提出一种基于非接触式的高精度微弱感应电流信息获取与解调测试方法,通过下变频与数字锁相解决桥丝式电雷管等设备的电流监测难题,实现微弱电流的精准测量,研究采用“下变频-滤波处理-数字锁相”对系统进行优化,实现5~200 mA微弱电流的高精度获取。该方案突破传统接触式测量的电磁耦合干扰瓶颈,构建了从物理传感到数字解算的一体化检测体系。研究采用TMR作为前端感应单元,利用其高灵敏度与宽频响应特性,来弥补现有系统在高频段测量的技术难题。信号处理环节通过混频器将不同频段信号统一频率下变频至50 kHz,结合低通滤波与ADC,消除高频噪声干扰;后端利用FPGA实现百万次乘累加数字锁相运算,通过互相关检测原理分离目标信号与背景噪声型。经测试验证:在50 kHz~10 GHz频段范围内,系统检测精度达≤±0.65 mA,且实时性通过FPGA并行处理得到保障。非接触式检测方案通过传感器物理屏蔽与数字算法协同为电雷管安全监测、工业设备电流计量提供了低成本、高可靠性的技术路径,与广泛应用前景。
In industrial monitoring and safety detection,non-contact high-precision weak current detection is critical for key equipment reliability.To tackle traditional methods′signal distortion,noise interference and low high-frequency accuracy,this study proposes a non-contact high-precision acquisition and demodulation method for weak induced currents.Integrating down-conversion and digital phase-locking,it solves bridge-wire electric detonator current monitoring for precise weak current measurement.Optimized via“down-conversion-filtering-digital phase-locking”,the system achieves 5~200 mA high-precision acquisition,breaking through traditional contact measurement′s electromagnetic coupling bottleneck and establishing a physical sensing-to-digital calculation integrated system.Using a high-sensitivity,wide-frequency-response TMR sensor as front-end overcomes existing systems′high-frequency limitations.The signal processing stage down-converts multi-band signals to 50 kHz via mixer,with low-pass filtering and ADC suppressing high-frequency noise;the back-end implements million-scale multiply-accumulate digital phase-locking via FPGA,separating target signals from noise via cross-correlation.Experiments show 50 kHz~10 GHz frequency range,≤±0.65 mA accuracy,FPGA ensuring real-time performance.Combining sensor physical shielding and digital algorithms,this low-cost,highly reliable non-contact scheme serves electric detonator safety monitoring and industrial equipment current measurement with broad prospects.In the field of industrial monitoring and safety inspection,non-contact high-precision detection of weak current signals is a core technology for ensuring the operational reliability of critical equipment.To address the problems of signal distortion,noise interference at high frequencies,and low detection accuracy in traditional methods,this study proposes a non-contact high-precision acquisition and demodulation method for weak induced currents.By combining down-conversion and digital phase-locked detection,the method solves the current monitoring problem ofdevices such as bridge-wire electric detonators,enabling precise measurement of weak currents.The system is optimized through a“down-conversion-filtering-digital phase-locking”architecture,achieving high-precision acquisition of weak currents in the range of 5~200 mA.This approach overcomes the bottleneck of electromagnetic interference inherent in traditional contact-based measurements and establishes an integrated system from physical sensing to digital processing.A TMR sensor is used as front-end sensing unit,leveraging its high sensitivity and wide frequency response to address the technical challenges of high-frequency current measurement.In the signal processing stage,multi-band signals are down-converted to 50 kHz using a mixer;low-pass filtering and ADC are then applied to suppress high-frequency noise.At the back end,a digital phase-locked loop based on million-scale multiply-accumulate operations is implemented using an FPGA,which separates target signals from background noise through cross-correlation detection.Experiments results show that in the frequency range of 50 kHz~10 GHz,the system achieves a detection accuracy of≤±0.65,with real-time performance ensured by FPGA parallel processing.This non-contact detection method,through the synergy of sensor shielding and digital algorithms,provides a low-cost and highly reliable technical solution for the safety monitoring of electric detonators and current measurement of industrial equipment,with broad application prospects.
作者
王耀利
徐徛征
王志斌
杨庆东
张磊
Wang Yaoli;Xu Jizheng;Wang Zhibin;Yang Qingdong;Zhang Lei(School of Electrical and Control Engineering,North University of China,Taiyuan 030051,China;Shanxi Intelligent Microwave Optoelectronic Technology Innovation Center,Taiyuan 030051,China)
出处
《仪器仪表学报》
北大核心
2025年第6期96-107,共12页
Chinese Journal of Scientific Instrument
基金
山西省基础研究计划(202403021221120)项目资助。
关键词
微弱感应电流
TMR
高精度
噪声抑制
weak induced current
TMR
high precision
noise suppression
