全张量磁梯度信号同步采集电路设计

发布时间：2018-04-02 06:52

本文选题：磁梯度张量　切入点：同步采集　出处：《吉林大学》2017年硕士论文

【摘要】：随着科学进步和发展,磁力勘探探测技术在矿产勘探、军事探潜以及未爆炸物检测等领域有着广泛应用。与传统的磁力勘探相比,磁梯度张量测量具有其特有的突出异常场弱化背景场等优点。全张量磁梯度测量技术主要测量磁矢量的三个分量在地理坐标系三个方向上的空间变化率,但由于磁梯度传感器的两个拾取环在测量过程中对共模磁场的抑制能力有限,从而在目标(梯度)信号中引入共模噪声。通常情况下,需要一个三轴的超导量子干涉器(Superconducting Quantum Interference Device,SQUID)对6个平面梯度计进行不平衡度修正来消除该共模噪声。针对这一问题,本文设计了基于现场可编程门阵列(Field-Programmable Gate Array,FPGA)的八通道同步采集电路,并利用并行连接方式,实现了九路信号的同步采集,并通过九路信号的同步性实验和全张量信号采集实验验证了方案的可行性和可靠性。本文具体的研究内容有:(1)研究了全张量磁梯度测量原理,在此基础上针对磁梯度张量测量的测量对象,设计了信号采集电路的整体方案。根据总体设计方案,研制了全张量磁梯度信号同步采集电路,主要包括电源模块、放大电路模块、A/D转换模块、FPGA控制模块、数据储存模块及与上位机通讯模块,实现了对九路模拟信号同步进行采集、放大、转换、传输等功能。(2)开发了上位机控制程序。设置了上位机与通讯模块的传输方式、数据的储存格式和输出形式,编写了数字滤波、电压转换及信号输出电压与磁场梯度的转换等程序,实现了数据传输、存储、分析、显示等功能。(3)开展室内实验,对全张量磁梯度信号同步采集电路进行了性能参数测试与可行性验证实验。获得了电路的静噪水平,实验表明设计的采集电路可以实现全张量9路SQUID测量通道的同步采集。
[Abstract]:With the progress and development of science, magnetic exploration technology has been widely used in the fields of mineral exploration, military submarine exploration and non-explosive detection. The magnetic gradient Zhang Liang measurement has its unique advantages such as prominent anomalous field weakening background field and so on. The magnetic gradient measurement technique mainly measures the spatial change rate of three components of magnetic vector in three directions of geographical coordinate system. However, due to the limited ability of the two pickup rings of the magnetic gradient sensor to suppress the common-mode magnetic field in the measurement process, common-mode noise is introduced into the target (gradient) signal. In order to eliminate the common-mode noise, a three-axis superconducting Quantum Interference device squid is needed to correct the unbalance of six planar gradiometers. In this paper, an eight-channel synchronous acquisition circuit based on Field-Programmable Gate FPGA (Field Programmable Gate Array) is designed. The feasibility and reliability of the scheme are verified by the synchronous experiment of nine signals and the experiment of collecting all Zhang Liang signals. On this basis, the whole scheme of signal acquisition circuit is designed for the measuring object of magnetic gradient Zhang Liang. According to the overall design scheme, the synchronous acquisition circuit of all Zhang Liang magnetic gradient signal is developed, which mainly includes the power supply module. Amplifier circuit module A / D conversion module FPGA control module, data storage module and communication module with host computer to realize the acquisition, amplification, conversion of nine analog signals synchronously. The control program of upper computer is developed. The transmission mode between upper computer and communication module, the storage format and output form of data are set up, and the digital filter is compiled. Programs such as voltage conversion and signal output voltage conversion with magnetic field gradient have realized data transmission, storage, analysis, display and other functions. The performance parameter test and feasibility verification experiment of the synchronous acquisition circuit of all Zhang Liang magnetic gradient signal are carried out, and the static noise level of the circuit is obtained. The experiment shows that the designed acquisition circuit can realize synchronous acquisition of 9 channels of SQUID measurement channel.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM936

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