MRS-TEM联用仪拉莫尔频率测量模块的研制

发布时间：2018-03-28 17:33

本文选题：ARM　切入点：CPLD　出处：《吉林大学》2015年硕士论文

【摘要】：伴随着科技水平技术的不断提高，，水的重要性和用途越来越大，可是水资源在地球上的很多地区却相当贫乏，直接导致了该地方各方面的落后。所以，为了解决上述的种种问题，探求一种探水方式是极其重要的。到现在为止，核磁共振（MRS）找水法是仅有的一种方式，它不需要进行挖掘即可探测出水的位置与容量。瞬变电磁法（TEM）则是一种间接方式对水资源进行探测，效果也较好，它的优势是探测范围比MRS更为广泛。联用仪就是综合了MRS的准确和TEM的范围，以这两者的互补技术研发出了MRS与TEM联用仪，简称联用仪。本论文的研究内容为核磁共振联用仪的拉莫尔频率测量模块，根据核磁共振找水方法的原理，最基本的已知量就是要知道地磁场的频率，而地球上每个位置的磁场都是不相同的，只有准确测量出地磁场的大小和地磁场作用下氢质子的进动频率。才能在核磁共振仪器工作过程中取得最大的信号强度和效果。因此，准确测量出拉莫尔频率对于联用仪来讲是非常重要的一个开发模块。它直接决定了整个仪器的量化结果。模块的主要下位机控制采用ARM单片机进行控制和信号采集，采用CPLD进行数字信号的测量，上位机采用Labview软件以子VI的形式集成于核磁共振联用仪的上位机软件中。根据研究内容，本文解决的问题有：核磁共振联用仪拉莫尔频率测量模块的集成，核磁共振联用仪总线下模块的挂接，上位机Labview软件的人机界面，拉莫尔频率测量模块主控电路的开发，拉莫尔频率测量模块极化电路的开发，拉莫尔频率测量模块放大电路的开发，拉莫尔频率测量模块切换电路的开发，拉莫尔频率测量模块信号处理测量电路的开发，模块的电容自动化配谐方法的研制，模块的结构研制等等。本文主要是开发一个拉莫尔频率测量系统模块集成于整个联用仪器当中，模块工作原理采用质子旋进的方式对地磁场的拉莫尔频率进行精准测量，测量精度达到0.05Hz。
[Abstract]:With the development of science and technology, water is becoming more and more important and useful, but water resources are very poor in many areas of the earth, which directly leads to the backwardness in all aspects of the area. In order to solve these problems, it is extremely important to find a way to detect water. So far, MRS is the only way to find water. It can detect the position and capacity of effluent without digging. Transient electromagnetic method (temm) is an indirect way to detect water resources, and the effect is good. Its advantage is that the detection range is more extensive than that of MRS. The combined instrument combines the accuracy of MRS and the range of TEM. With the complementary technology of the two, the combined instrument of MRS and TEM is developed. According to the principle of nuclear magnetic resonance (NMR) looking for water, the most basic known quantity is to know the frequency of geomagnetic field. However, the magnetic field in every position of the earth is different. Only by accurately measuring the magnitude of the geomagnetic field and the precession frequency of the hydrogen proton under the action of the geomagnetic field, can the maximum signal intensity and effect be obtained during the operation of the nuclear magnetic resonance instrument. It is a very important development module to measure the Lammore frequency accurately. It directly determines the quantization result of the whole instrument. The main lower computer control of the module is controlled by ARM single chip microcomputer and the signal is collected. The digital signal is measured by CPLD, and the upper computer is integrated into the upper computer software of nuclear magnetic resonance (NMR) by Labview software in the form of sub-VI. According to the research content, the problems solved in this paper are: the integration of the frequency measurement module of the nuclear magnetic resonance instrument, the connection of the module under the nuclear magnetic resonance instrument bus, the man-machine interface of the upper computer Labview software, The development of the main control circuit of the frequency measurement module, the polarization circuit of the frequency measurement module, the amplification circuit of the frequency measurement module, the switch circuit of the frequency measurement module, The development of signal processing and measurement circuit of Rammore frequency measurement module, the development of the module's capacitive automatic harmonic matching method, the development of the module's structure and so on. In this paper, a module of Rammore frequency measurement system is developed and integrated into the whole instrument. The working principle of the module is to accurately measure the frequency of the geomagnetic field by proton precession, and the measuring precision is up to 0.05 Hz.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P641.7;P631.2

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