基于扭转应力非晶丝低频磁阻抗效应的无圈磁通门传感器研制.pdf

基于扭转应力非晶丝低频磁阻抗效应的无圈磁通门传感器研制Coil-·less Fluxgate Sensor Based on Low·-FrequencyMagneto—Impedance Effect in Twisted Amorphous Wire20 1 2年6月江苏大学硕士学位论文摘 要随着科学技术的发展，微弱磁场的测量在军事、航空、海洋、地质、考古以及医学等领域获得了越来越多的应用，这些学科领域的不断发展，对微弱磁场测量仪的要求越来越高而磁传感器是微弱磁场测量仪的关键和基础，它的性能直接影响着整个仪器的精度和灵敏度本文通过总结国内外磁通门传感器的有关研究状况和研究成果，设计了一种基于扭转应力非晶丝低频磁阻抗效应的无圈磁通门传感器，它的敏感体是软磁特性非常优异的钴基非晶态合金丝，并用PVC材料制作了传感器的探头装置介绍了非晶态合金的基本特性及GMI效应，详细阐述了施加扭转应力非晶丝低频磁阻抗效应的理论进而设计了传感器的硬件电路，把方波发生电路、四阶低通滤波电路以及功率放大电路产生的正弦信号作为激励源，对非晶丝直接激励然后，设计了级联带通滤波电路、检波电路以及低通滤波电路对非晶丝两端的输出信号进行处理。

由于激励信号直接通过非晶丝并且直接在非晶丝两端取输出信号，因此，利用非晶丝扭转应力设计的传感器就无需激励线圈和感应线圈，从而使得传感器的敏感体体积大大减小在完成硬件设计的基础上，实验研究了扭转应力非晶丝的低频磁阻抗效应用长直螺线管产生外加磁场，测试了非晶丝两端输出电压的二次谐波与非晶丝的扭转应力以及激励电流有效值之间的关系，找到了传感器具有最佳性能时的相关参数最后，完成了传感器的整体调试和电路板的制作通过对传感器的静态标定，给出了它的静态特性实验结果表明：本传感器能够检测+50A／m范围内的静态弱磁场，且具有较好的线性度，灵敏度和重复性，达到了预定的技术指标关键词：扭转应力，非晶丝，低频磁阻抗效应，无圈磁通门基于扭转应力非晶丝低频磁阻抗效应的无圈磁通门传感器研制II江苏大学硕士学位论文With the development of science and technology，the measurement of weakmagnetic field is applied more and more in the military，aviation，marine，geological，archaeological and medical fields．The requirement of weak magnetic field measuringinstrument is higher and higher with the development of these disciplines．But the keyand basis of weak magnetic field measuring instruments are the magnetic sensors andtheir performance directly affect the accuracy and sensitivity of the whole instrument．In this thesis，a coil—less fluxgate sensor is designed through summarizing thedevelopment and research of the fluxgate sensor，which based on low-frequencymagneto—impedance effect in twisted amorphous wire．The Co-based amorphous wireis selected for the sensor’S measuring element，and the sensor probe device is madewith PVC material．The basic characteristics of the amorphous alloy and its GMI effect aredescribed，and the theory of low-frequency magneto—impedance effect in twistedamorphous wire is elaborated．And then，the hardware。

circuit of the sensor isdesigned．The driving current is produced by the square wave generating circuit，thefourth-order low—pass filter circuit and the power amplifier circuit， which directlyexcites the amorphous wire．Then，the cascaded band-pass filter circuit，the detectorcircuit and low-pass filter circuit are designed to process the output signal from bothends of the amorphous wire．The sensor need not excitation coil and induction coilbecause of the driving current is directly through the wire and output signal is directlytook from the both ends of the wire，SO that the volume of the sensor can be reducedlargely．Low··frequency magneto-—impedance effect in twisted amorphous wire isresearched by some experiments after completing the design of circuit．The magneticfield is produced by the long straight solenoid，and the relationship between thesecond harmonic output from the both ends of the amorphous wire，the torsional stressof the amorphous wire and driving current is tested， and the relevant parameters forIII基于扭转应力非晶丝低频磁阻抗效应的无圈磁通门传感器研制the best performance of the sensor is found．Finally，the global debugging of the sensor and PCB are accomplished，and thestatic characteristics of the sensor are given．The experimental result shows that the sensor，which can measure the staticweak magnetic field ranging from-50A／m to 50A／m，has all excellent linearity，highsensitivity and good repeatability，and could reach the requirements of thespecification．Key words：torsional stress，amorphous wire，low．frequency magneto．impedanceeffect，coil—less fluxgate江苏大学硕士学位论文第一章1．11．21．3第二章目 录绪论…………………。

………………………… 1选题背景及意义……………………………………………………………1国内外研究现状……………………………………………………………2研究的主要内容……………………………………………………………4非晶态合金及其GMI效应……………………………………… 52．1非晶态合金…………………………………………………………………52．1．1非晶态合金定义………………………………………………………52．1．2非晶态合金的研究与发展…………………………………………一52．1．3非晶态合金的分类与制备…………￡………………………………62．1．4非晶态合金的基本特性……………………………………………72．2非晶态合金的GMI效应…………………………………………………．92．2．1 GMI效应………………………………………………………………………………92．2．2 GMI效应与激励电流频率的关系………………………………102．3本章小结…………………………………………………………………．12第三章扭转应力非晶丝低频磁阻抗效应理论……………………………………………．133．1扭转应力磁阻抗效应模型………………………………………………．．133．2二次谐波与扭转应力、激励电流、外场之间的关系…………………．153．2．1扭转应力g=o时输出电压的频谱分析……………………………153．2．2扭转应力对二次谐波响应幅值的影响……………………………173．2．3扭转应力对二次谐波响应灵敏度的影响…………………………193．2．4激励电流幅值对二次谐波响应灵敏度的影响……………………203．3本章小结…………………………………………………………………．21第四章传感器硬件电路设计………………………………………………………………224．1传感器总体设计……………………………………………………………224．2电源电路设计……………………………………………………………．224．2．1稳压电源电路结构…………………………………………………234．2．2稳压电源电路工作原理……………………………………………234．3信号发生电路设计………………………………………………………．244．3．1方波发生电路………………………………………………………254．3．2四阶低通滤波电路…………………………………………………264．3．3功率放大电路………………………………………………………304．4信号处理电路设计………………………………………………………．33V基于扭转应力非晶丝低频磁阻抗效应的无圈磁通门传感器研制4．4．1带通滤波电路………………………………………………………334．4．2级联带通滤波电路…………………………………………………。

384．4．3检波电路……………………………………………………………404．4．4二阶低通滤波电路…………………………………………………．424．5本章小结……………………………………………………………………44第五章实验调试及性能标定…………………………………………………………………．455．1非晶丝磁性能及传感器探头设计………………………………………．455．1．1钴基非晶丝磁性能…………………………………………………455．1．2传感器探头制作……………………………………………………455．2被测磁场产生装置设计…………………………………………………465．3扭转应力非晶丝低频。