Nowadays gmr material has been successfully used in some sensor applications like high resolution magnetic head used in computer , mram , magnetic sensors , current sensors , rotation speed sensors and so on 目前gmr巨磁阻材料已经在一些传感器技术领域获得了成功的应用，比如：计算机用高密度磁头，磁电阻随机存储器，磁场传感器，电流传感器，转速传感器等等。
The algorithm principle , hardware design and software design of the scheme are proposed and experimentally demonstrated ; the main contents of this thesis are as follows : firstly , we study the principle of the fiber optic weak magnetic sensor based on magnetostrictive effect . after analyzing the characters of the magnetic field sensing signals , we know that the magnetic field sensing signals ’ fundamental component is proportional to input dc magnetic field 叙述了该方案的原理、软硬件设计过程,并通过实验进行了验证,本文主要内容如下:首先,研究了基于磁致伸缩效应的光纤微弱磁场传感器传感原理以及输出信号的特征,分析得出在干涉仪处于正交工作点时,传感器输出信号的基频分量与被测直流磁场成正比关系。
In the thesis , a signal processing scheme of polarization - insensitive fiber optic michelson interferometric magnetic sensor is described : making the interferometer work near the quadrature with closed loop controlling working point method , the fundamental frequency component of the magnetic field sensing signals can be detected to measure the input direct current ( dc ) magnetic field by phase sensitive demodulation 本文主要介绍了偏振无关光纤michelson干涉型微弱磁场传感器信号处理的方案:通过闭环控制工作点算法使干涉仪工作在正交工作点处,再利用相敏检波算法提取传感器输出信号的基频分量,以测量直流磁场的大小。
Besides , we use software smooth filtering to minish the influence of white noise and high - frequency noise , ground connection and shield technology to eliminate electromagnetic interference , and rational circuit distribution to attain high signal - to - noise of the whole fiber optic weak magnetic sensor system 另外,采用软件平滑滤波等处理以减小白噪声和高频噪声的影响,利用接地及屏蔽技术消除外界的电磁干扰,并对电路进行合理布局布线,以获得高信噪比的光纤微弱磁场传感器系统。
Then , we set up the experiment system . after stabling the working point , we measured the frequency response of the system , then measured the output of the dc magnetic field under different ac modulating magnetic fields . the experimental results show that the output of the system is linear with the detected signal when the measured magnetic field is small 接着,本文搭建了微弱磁场传感器实验系统,在稳定了系统工作点的前提下,对系统频率响应进行了测试,并对传感器在不同交流调制磁场下的直流磁场探测时系统的输出进行了测试,实验结果表明,当被测磁场较小时,系统输出信号与被测信号成正比关系。
We improve the sensor head structure on the basis of analyzing the factors influencing the sensor head sensitivity . using thin fiber with 80 m and special framework , we get magnetic sensor head with small volume , high sensitivity and wide frequency response spectrum 在分析影响传感器的传感头灵敏度的因素的基础上,本文对传感器传感头结构进行了改进,整个传感头都采用80 m的细径光纤,通过特殊的骨架结构,实现了体积小、灵敏度高、频率响应范围宽的磁场传感器传感头。
In this thesis , a scheme of polarization - insensitive fiber optic michelson interferometric magnetic sensor is proposed on the base of analyzing several kinds of fiber optic magnetic sensors . the principle of the scheme has been expounded in detail . after designing the sensor head , we set up the experiment system , and then completed the experiment 本文在对几种光纤磁场传感器进行分析的基础上,确定了基于磁致伸缩的偏振无关光纤michelson干涉型微弱磁场传感方案,对该方案的工作原理进行了详细分析,设计了传感器的传感头结构,并搭建实验系统,进行了实验检测。
