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  本文選題：瞬變電磁　切入點：信號源　出處：《成都理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：瞬變電磁法,又稱為時間域電磁法,是一種建立在電磁感應(yīng)基礎(chǔ)上的時間域人工源電磁探測方法,主要應(yīng)用于地質(zhì)探測領(lǐng)域。其中瞬變電磁接收機作為數(shù)據(jù)采集和存儲的主要途徑,其性能直接影響到后期的數(shù)據(jù)處理和解釋。因此,人們對瞬變電磁接收機的性能提出了更高的要求。隨著現(xiàn)代電子技術(shù)和計算機技術(shù)的不斷發(fā)展,高分辨率、高靈敏度和高抗干擾度的瞬變電磁儀器成為研究人員研究的主要方向。而在儀器的研制過程中,每次實驗都需要到野外進行測試,這耗費了大量的時間、人力和物力。如果能夠模擬野外實測信號就能在室內(nèi)進行儀器的測試,這不僅能降低實驗成本,改進儀器,而且還能在野外作業(yè)前對儀器進行標(biāo)定。市場上現(xiàn)有的通用信號發(fā)生器,很難模擬出適用于瞬變電磁儀器的原始信號波形,因此,本文設(shè)計了一種為實驗室內(nèi)瞬變電磁儀器的研發(fā)提供參考信號的專用信號源。本文依托于國土資源部公益性項目“基于無人機的半航空瞬變電磁勘查技術(shù)研究”(項目編號:201311037),論文的主要內(nèi)容如下:第1章首先介紹了瞬變電磁法的研究背景和瞬變電磁專用信號源的研制意義;然后論述了信號發(fā)生器的發(fā)展歷史和技術(shù)現(xiàn)狀;最后根據(jù)本課題的要求,提出了本系統(tǒng)的設(shè)計指標(biāo)。第2章從理論上分析了瞬變電磁信號產(chǎn)生的原理及其特征,進而建立了瞬變電磁信號的仿真模型;分析了影響瞬變電磁信號的主要噪聲及其特點,基于對野外實測數(shù)據(jù)的分析,研究了油動無人直升機對瞬變電磁接收機的影響,并建立相應(yīng)的matlab仿真模型,為瞬變電磁專用信號源的研制奠定了理論基礎(chǔ)。第3章介紹了DDS原理,通過方案論證,提出了基于SOPC的系統(tǒng)設(shè)計方案。詳細闡述了相位累加器模塊和SRAM控制切換模塊的設(shè)計,采用高速的數(shù)模轉(zhuǎn)換芯片ISL5961和高壓擺率的運放芯片THS4271設(shè)計了數(shù)模轉(zhuǎn)換電路和低通濾波電路并介紹了電源部分的設(shè)計。第4章采用圖形化編程方法的Lab VIEW設(shè)計了上位機軟件,對波形數(shù)據(jù)產(chǎn)生、顯示和參數(shù)處理模塊的功能和設(shè)計方法進行了介紹。第5章首先提出了系統(tǒng)的測試方案。采用自底向上的原則,對電源的紋波進行測試,并對FPGA內(nèi)部模塊進行功能仿真測試。最后對整個系統(tǒng)進行了總體測試,測試結(jié)果表明基本實現(xiàn)了預(yù)期的功能。通過這些研究,有利于減少瞬變電磁接收儀器研制過程中的測試成本,對于提高其性能指標(biāo)和儀器標(biāo)定具有重要意義。
[Abstract]:Transient electromagnetic method, also known as time-domain electromagnetic method, is a time-domain artificial source electromagnetic detection method based on electromagnetic induction. The transient electromagnetic receiver is the main way of data acquisition and storage, and its performance directly affects the later data processing and interpretation. People demand higher performance of transient electromagnetic receiver. With the development of modern electronic technology and computer technology, high resolution, Transient electromagnetic instruments with high sensitivity and high anti-jamming degree have become the main research direction of researchers. However, in the development of the instrument, each experiment needs to be tested in the field, which takes a lot of time. Manpower and material resources. If you can simulate the field measured signals, you can test the instruments indoors, which can not only reduce the cost of the experiment, but also improve the instruments. Moreover, the instrument can be calibrated before the field operation. It is very difficult to simulate the original signal waveform suitable for transient electromagnetic instrument in the existing general signal generator on the market, so, In this paper, a special signal source is designed to provide reference signal for the research and development of laboratory transient electromagnetic instruments. This paper is based on the public welfare project of Ministry of Land and Resources, "Research on Semi-Aeronautical transient electromagnetic Prospecting Technology based on UAV" (. Item number: 201311037. the main contents of this paper are as follows: in Chapter 1, the research background of transient electromagnetic method and the significance of developing special signal source for transient electromagnetic are introduced. At last, according to the request of this subject, the design index of the system is put forward. In chapter 2, the principle and characteristics of transient electromagnetic signal generation are analyzed theoretically. Then, the simulation model of transient electromagnetic signal is established, and the main noise and its characteristics that affect the transient electromagnetic signal are analyzed. Based on the analysis of field measured data, the influence of oil-operated unmanned helicopter on the transient electromagnetic receiver is studied. The corresponding matlab simulation model is established, which lays a theoretical foundation for the development of special transient electromagnetic signal source. Chapter 3 introduces the principle of DDS and demonstrates the scheme. The system design scheme based on SOPC is proposed, and the design of phase accumulator module and SRAM control switch module are described in detail. The digital-analog conversion circuit and low-pass filter circuit are designed by using high-speed digital-analog converter chip ISL5961 and high-voltage swing rate operational amplifier chip THS4271, and the design of power supply part is introduced. In chapter 4, the upper computer software is designed by using graphical Lab VIEW. The function and design method of waveform data generation, display and parameter processing module are introduced. In chapter 5, the test scheme of the system is put forward firstly, and the ripple of power supply is tested by bottom-up principle. Finally, the whole system is tested, and the test results show that the expected function is basically realized. It is beneficial to reduce the testing cost in the development of transient electromagnetic receiver, and it is of great significance to improve its performance index and instrument calibration.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P631.325

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本文編號：1622309