水下金属物体电磁反射特性实验研究

发布时间：2018-06-21 22:43

本文选题：电磁探测 + 水下电磁场　；参考：《电子科技大学》2015年硕士论文

【摘要】：随着海洋资源开发利用逐步成为国家重点发展领域,水下金属物体,如航行器、金银、贵重金属的探测技术也快速发展。对于沉埋在水底的金属物体,常规的探测手段如图像声纳等,难以有效进行探测,而采用电磁探测手段对于沉埋的金属物体能够取得较好的探测效果。本文对水下金属物体电磁反射特性进行了研究,为水下金属物体电磁探测提供了理论和实验依据。本论文对水下金属物体电磁反射特性进行了理论分析与实验研究,首先对水下磁探测的发展和国内外现状进行了介绍,给出了金属物体对磁偶极子辐射场的电磁反射原理,对磁偶极子辐射源的空间分布和水下衰减进行了理论分析与仿真计算,根据金属物体电磁反射场的特点,设计了电磁反射场检测传感器的布局方式,并设计了适用于水下主动电磁探测的发射线圈和发射电路,选择了适宜频段的电磁传感器,搭建了数据采集系统,并编写了数据采集分析软件等,针对水下电磁反射信号的特点,论文提出了水下金属物体电磁反射信号的小波降噪方法、幅度包络检测方法、瞬时特征提取方法及发射线圈等效阻抗计算方法,并给出了通过电磁反射场幅度变化和发射线圈等效阻抗变化情况判断金属物体类型的一些依据,最后使用铝和铁两种材质的金属物体进行了淡水中的电磁反射特性实验,对电磁反射场和发射线圈等效阻抗进行了信号采集与分析,验证了电磁反射的检测方法、信号处理方法及特征提取方法,在一定条件下实现了金属物体判断及金属类型区分。
[Abstract]:With the development and utilization of marine resources, the exploration technology of underwater metal objects, such as navigators, gold and silver, and precious metals, has gradually become a key area of national development. Conventional detection methods such as image sonar are difficult to detect metal objects buried on the bottom of water, but the electromagnetic detection method can obtain better detection effect for buried metal objects. In this paper, the electromagnetic reflection characteristics of underwater metal objects are studied, which provides a theoretical and experimental basis for the electromagnetic detection of underwater metal objects. In this paper, the electromagnetic reflection characteristics of underwater metal objects are theoretically analyzed and experimentally studied. Firstly, the development of underwater magnetic detection and the present situation at home and abroad are introduced, and the electromagnetic reflection principle of metal objects to magnetic dipole radiation field is given. The spatial distribution and underwater attenuation of magnetic dipole radiation source are theoretically analyzed and simulated. According to the characteristics of electromagnetic reflectance field of metal object, the layout mode of electromagnetic reflection field detection sensor is designed. The launching coil and transmitting circuit suitable for underwater active electromagnetic detection are designed. The electromagnetic sensor with suitable frequency band is selected, the data acquisition system is built, and the software for data acquisition and analysis is compiled. According to the characteristics of underwater electromagnetic reflection signal, wavelet denoising method, amplitude envelope detection method, instantaneous feature extraction method and equivalent impedance calculation method of transmitting coil are proposed in this paper. Some evidences for judging the type of metal objects are given by the variation of electromagnetic reflectance field amplitude and equivalent impedance of the emitter coil. Finally, the electromagnetic reflection characteristics of metal objects of aluminum and iron are tested in fresh water. The signal acquisition and analysis of the electromagnetic reflectance field and the equivalent impedance of the transmitting coil are carried out to verify the detection method, the signal processing method and the feature extraction method of the electromagnetic reflection. Under certain conditions, the judgment of the metal object and the classification of the metal type are realized.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P715.5

【参考文献】