基于GMM地质预报用精密可控震源基础研究

发布时间：2018-04-14 02:20

本文选题：可控震源 + 超磁致伸缩换能器　；参考：《山东大学》2015年硕士论文

【摘要】：地震勘探是石油与天然气资源的重要勘察手段,传统地震勘探采用炸药作为勘探震源,对环境破坏严重,且有一定的危险性。常用的陆地可控震源激发波形可控,可实现高分辨率地震探测,而且对环境没有破坏性。其中,电磁驱动式可控震源通过交变的电磁场驱动铁磁材料产生激震所需的推力,具有轻便、安全等特点,适于进行浅层地震勘探,但却存在激发信号能量较弱、信噪比低等缺点。为了解决这一问题,本文研究将超磁致伸缩换能器用作电磁驱动式可控震源的振动元件,由于超磁致伸缩材料与一般铁磁材料相比,具有更高的磁机转化效率,因此超磁致伸缩换能器作为可控震源的振动元件可以取得较好的激震效果。为了满足超磁致伸缩换能器激发产生的扫描信号相位和幅值要求,本文对超磁致伸缩换能器的电磁驱动部分和震源平板-大地耦合系统部分进行了研究,主要工作包括以下几点：(1)比较了几种描述磁滞现象的理论模型,并结合扫描信号驱动超磁致伸缩换能器的工作情况,将换能器的磁滞现象视为相位滞后,使用延时环节予以描述,结合未考虑磁滞的系统线性模型,得到了磁致伸缩换能器的数学模型并进行了仿真验证。(2)采用Lysmer方程作为平板-大地耦合系统的振动模型,应用四阶龙格-库塔方法求解得到了耦合系统在扫描信号负载驱动下的输出响应,并依据幅频响应曲线分析了影响系统振动特性的因素。(3)根据可控震源地震勘探对扫描信号无相差滞后的控制要求,采用相位补偿加PID反馈的方法对超磁致伸缩换能器进行了控制补偿。通过相位补偿的方法使换能器的输出位移和输入电流同相,并应用PI[)反馈进一步降低了换能器的输出位移误差,改善了系统的响应特性。实验结果表明,本文采用的控制策略可以有效的消除在宽频程扫描信号驱动下超磁致伸缩换能器输出信号的滞后。
[Abstract]:Seismic exploration is an important exploration method for oil and natural gas resources. The traditional seismic exploration uses explosive as the source of seismic exploration, which has serious damage to the environment and is dangerous to some extent.The excitation waveform of the commonly used land vibroseis is controllable, which can realize high resolution seismic detection, and it is not destructive to the environment.Electromagnetically driven vibroseis are suitable for shallow seismic exploration, but the excitation signal energy is weak.Low signal-to-noise ratio and other shortcomings.In order to solve this problem, the giant magnetostrictive transducer is used as the vibration element of the electromagnetic drive vibroseis, because the giant magnetostrictive material has higher magneto-mechanical conversion efficiency than the common ferromagnetic material.Therefore, the Giant Magnetostrictive Transducer can be used as vibration element of vibroseis to obtain better excitation effect.In order to meet the requirements of the scanning signal phase and amplitude generated by the excitation of the giant magnetostrictive transducer, the electromagnetic driving part of the giant magnetostrictive transducer and the coupled system of the seismic plate and the earth are studied in this paper.The main work includes the following points: 1) several theoretical models describing the hysteresis phenomenon are compared, and the hysteresis phenomenon of the transducer is considered as the phase lag in the light of the working conditions of the scanning signal driven giant magnetostrictive transducer.The mathematical model of magnetostrictive transducer is obtained by using the delay link and the linear model of the system without considering the hysteresis. The simulation results show that the Lysmer equation is used as the vibration model of the plate-earth coupling system.The fourth order Runge-Kutta method is applied to obtain the output response of the coupled system driven by the scanning signal load.Based on the amplitude-frequency response curve, the factors affecting the vibration characteristics of the system are analyzed.The control compensation of giant magnetostrictive transducer is carried out by the method of phase compensation and PID feedback.The output displacement and input current of the transducer are in-phase by phase compensation, and the output displacement error of the transducer is further reduced by using Pi [) feedback, and the response characteristics of the system are improved.The experimental results show that the proposed control strategy can effectively eliminate the hysteresis of the output signal of the giant magnetostrictive transducer driven by the wide-range scanning signal.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.4

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