基于虚拟仪器的电阻成像技术的硬件系统设计

发布时间：2018-05-02 21:36

本文选题：电阻抗成像 + 虚拟仪器　；参考：《太原理工大学》2012年硕士论文

【摘要】：在医学领域虽有多种成熟的成像方式,如X光、CT技术等,但每种方式都有其基本的缺点。而在工业领域上两相流或者多相流的研究和发展较为缓慢,究其原因就是该领域缺乏有效的检测技术。所以在医学和工业上都迫切需要一种安全而又可靠地技术来满足上述需求。在上世纪七十年代末,先进的发达国家兴起了一门新的断层成像技术：电阻抗成像(Electrical Impedance Tomography, EIT)技术。该技术的一系列优点,如可视化、无辐射、低成本和实时成像等,已引起了工业和医学检测技术研究人员的注意。由于其潜在的价值,它已经成为众多检测技术中一个重要的研究方向。随后的八十年代,由美国国家仪器有限公司提出“虚拟仪器”的概念对仪器仪表领域产生了较大的影响,尤其改变了许多传统的测量和控制方法。而且随着技术的发展和进步,虚拟仪器技术将给测试、计量和控制等其他领域提供一个非常好的设计平台。本文初步探讨了把“虚拟仪器”技术引入到电阻抗成像领域,从而使得电阻抗成像技术能够得到更深入和更广阔的发展。本文作者研究了电阻抗成像系统的硬件结构,提出了以虚拟仪器为核心的电阻抗成像的硬件系统,并根据系统总分总和模块化的思想设计出了整个硬件系统及其子模块。主要工作如下： (1)分析了EIT硬件系统的性能,阐述了目前EIT的驱动和测量的方式,以及系统结构,在此基础上设计了一套EIT系统,同时给出了硬件结构的详细电路。 (2)首次从软件和硬件的角度把虚拟仪器引入到了电阻抗成像领域,并根据二者的特点,制作了以虚拟仪器为核心的EIT硬件电路。 (3)在QuartusII环境下,用Verilog HDL语言开发了可在CPLD上运行的程序。 (4)详细介绍了信号解调的方法,并对比了各种方案,最终选择了数字正交解调,并用LabVIEW软件编写了程序从而实现该模块。 (5)首先测试了硬件系统的各个子模块,然后整合各模块构建EIT的硬件平台。并在该硬件系统上进行了相关的实验,而后分析和总结了实验结果,最终表明本文的硬件系统是可行的。最后,本文作者给出了后续工作的重心和提高系统性能的方向。
[Abstract]:Although there are many mature imaging methods in the field of medicine, such as X-ray CT technology, each method has its basic disadvantages. The research and development of two-phase flow or multiphase flow is slow in the industrial field, which is due to the lack of effective detection technology in this field. So there is an urgent need for a safe and reliable technology in medicine and industry to meet these needs. In the late 1970s, a new fault imaging technology, Electrical Impedance Tomography (EITT), was developed in advanced developed countries. A series of advantages of this technology, such as visualization, radiation-free, low cost and real-time imaging, have attracted the attention of researchers of industrial and medical detection technology. Because of its potential value, it has become an important research direction of many detection technologies. In the 1980s, the concept of "virtual instrument" was put forward by the National instrument Company of the United States, which had a great influence on the field of instrument and instrument, especially changed many traditional methods of measurement and control. With the development and progress of technology, virtual instrument technology will provide a very good design platform for other fields such as testing, metrology and control. In this paper, the introduction of "virtual instrument" technology into the field of electrical impedance imaging is preliminarily discussed, so that the electrical impedance imaging technology can be developed more deeply and widely. In this paper, the hardware structure of the electrical impedance imaging system is studied, and the hardware system of the electrical impedance imaging system with virtual instrument as the core is put forward, and the whole hardware system and its sub-modules are designed according to the idea of the total division and modularization of the system. The main tasks are as follows: 1) the performance of EIT hardware system is analyzed, the driving and measuring mode of EIT and the system structure are expounded. A set of EIT system is designed on the basis of this, and the detailed circuit of the hardware structure is given at the same time. For the first time, the virtual instrument is introduced into the field of electrical impedance imaging from the point of view of software and hardware. According to their characteristics, the EIT hardware circuit with virtual instrument as the core is made. In the environment of QuartusII, the program that can run on CPLD is developed with Verilog HDL language. Finally, the digital quadrature demodulation is selected, and the program is written by LabVIEW software to realize the module. 4) the method of signal demodulation is introduced in detail, and various schemes are compared. Finally, digital quadrature demodulation is selected. First, the sub-modules of the hardware system are tested, and then the hardware platform of EIT is constructed by integrating each module. The experiments are carried out on the hardware system, and the experimental results are analyzed and summarized. Finally, it is proved that the hardware system in this paper is feasible. Finally, the author gives the center of gravity and the direction of improving the system performance.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH772.2

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