基于双参数控制的宽频电磁探测发射关键技术研究

发布时间：2018-04-10 03:02

本文选题：电磁探测　切入点：浅地表　出处：《吉林大学》2017年硕士论文

【摘要】：目前,频率域电磁探测技术被广泛应用于浅层地质探测,工程地质调查,土壤检测,地下设施勘查及地下埋藏金属物、未爆炸物探测等。其探测原理是通过向地下发射不同频率的电磁波,遇到电阻率异常体时,产生涡流形成二次场,通过对二次场的信息进行采集和分析,来对埋藏的电阻率异常体进行定位及成像。浅地表电磁探测技术发射部分主要负责产生发射脉冲控制信号,并经功率放大电路和发射天线在空间中建立一次场。发射系统主要分为三部分:控制器部分,功率变换部分,发射天线部分。其中,控制器部分分为主控制器和从控制器,分别负责控制发射脉冲信号幅值和发射脉冲信号的频率及波形;功率变换器部分由Buck电路和全桥电路构成,可控放大发射的脉冲信号;天线部分包括匹配电路和发射线圈,负责向空间中发射不同频率的电磁波,建立一次场。本文以现有仪器为基础,采用双参数控制技术,解决了现有发射系统宽频发射时存在的一些问题。通过SIMULINK平台对发射系统进行计算及仿真,对比了改进前后发射系统发射的脉冲信号。利用DSP+FPGA搭建了硬件平台,验证了仿真的合理性和可行性,达到了预期的效果,在提高了系统稳定性的同时,保证系统的探测深度和探测效率,对埋藏于浅地表的电阻率异常体有较好的探测效果。
[Abstract]:At present, frequency-domain electromagnetic detection technology is widely used in shallow geological exploration, engineering geological survey, soil detection, underground facilities exploration and underground buried metal objects, non-explosive detection and so on.The detection principle is to generate eddy current to form a secondary field by sending electromagnetic waves of different frequencies to the ground, and to collect and analyze the information of the secondary field when the body with abnormal resistivity is encountered.To locate and image buried resistivity anomalies.The emission part of the electromagnetic detection technology is mainly responsible for generating the pulse control signal and establishing a field in the space through the power amplifier circuit and the transmitting antenna.The transmitting system is divided into three parts: controller, power conversion and antenna.The controller is divided into main controller and slave controller, which is responsible for controlling the amplitude of the transmitted pulse signal and the frequency and waveform of the transmitted pulse signal, respectively. The power converter is composed of Buck circuit and full-bridge circuit.The antenna consists of matching circuit and transmitting coil, which is responsible for transmitting electromagnetic waves of different frequencies into space and establishing a primary field.Based on the existing instruments, this paper solves some problems existing in the broad-band transmission of the existing launch system by adopting the technology of two-parameter control.The transmission system was calculated and simulated by SIMULINK platform, and the pulse signals of the improved launch system were compared.The hardware platform is built by using DSP FPGA, which verifies the rationality and feasibility of the simulation, and achieves the expected effect. While improving the stability of the system, it ensures the detection depth and efficiency of the system.It has good detection effect on resistivity anomaly buried on shallow surface.
【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】：P631.325

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