【作者】 韩滨澧；

【导师】 张晓明；

【作者基本信息】 中北大学 ， 仪器科学与技术， 2024， 硕士

【摘要】 随着海洋资源开发、海洋科研以及水下勘探等领域的发展,为保障海洋探测活动的安全进行以及相关探测信息的传输,多无人潜水器协同通信系统越来越重要,人类对水下通信的需求不断增加。现有的水下无线通信方式包括水声通信、光通信、电磁波通信,这些通信方式由于存在多径干扰严重、信号的衰减或技术难度大等问题,无法满足水下应用需求,而磁通信因其具有抗干扰能力强、通信带宽大、无多径效应、隐蔽性高等诸多优势可以较好地应用在水下中近距离通信中,其中通信效率和通信距离与线圈的设计密不可分,且目前针对磁通信的调制解调方式研究较少,因此本文围绕水下磁通信的线圈设计以及合适的调制解调方式结合水下实际环境进行相关研究。首先,本文基于电磁感应定律的基本理论,研究了水下磁感应通信的整体架构设计及其通信的基本原理,分析了磁偶极子模型在近场和远场的辐射特性,给出磁场强度和磁感应强度公式,介绍了单向和全向两种水下无线磁感应通信模型,对线圈的传输特性包括涡流损耗与线圈半径、工作频率的关系进行了仿真分析。其次,针对通信线圈的设计问题,建立了收发线圈的数学模型,分析了发送线圈最优功率分配情况,针对水下环境中接收节点受水体扰动或通信节点运动影响的情况,利用公式计算、仿真数据和试验对单向线圈和全向线圈进行了对比和验证,研究结果指出,采用全向磁通信模型可以显著减少接收端线圈方向的变动对通信效果造成的影响,波动性减小了97.19%,提高了通信的稳定性。再次,针对信号的调制解调以及路径损耗问题进行了分析,给出了最优调制解调方式并进行了仿真,通过仿真单向和全向线圈的涡流损耗,进一步验证了采用全向线圈进行通信的优势。最后,本文介绍了一种针对水下无线磁通信试验设计平台。该设计采用了BPSK调制技术,借助线圈之间的相互耦合用来实现信号的传递。在空气环境和水下环境对该装置进行测试,测试结果表明了全向线圈可以有效提升无线通信的稳定性以及无线磁通信系统作为水下通信应用的可行性,试验通信速率为212.5kbps,波动性减小了95%。更多还原

【Abstract】 With the development of Marine resources development,Marine scientific research and underwater exploration and other fields,in order to ensure the safety of ocean exploration activities and the transmission of relevant detection information,multiunmanned submersible cooperative communication system is becoming more and more important,and human needs for underwater communication are increasing.The existing underwater wireless communication methods include underwater acoustic communication,optical communication and electromagnetic wave communication.These communication methods cannot meet the needs of underwater applications due to serious multipath interference,signal attenuation or technical difficulty.Magnetic communication has many advantages such as strong anti-interference ability,large communication bandwidth,no multipath effect and high concealment,which can be well applied in underwater medium and short distance communication.Among them,communication efficiency and communication distance are closely related to coil design.Therefore,this thesis focuses on the coil design of underwater magnetic communication and the appropriate modulation and demodulation mode combined with the actual underwater environment.First of all,based on the basic theory of electromagnetic induction law,this thesis studies the overall architecture design and the basic principle of underwater magnetic induction communication,analyzes the radiation characteristics of magnetic dipole model in near field and far field,gives the formula of magnetic field intensity and magnetic induction intensity,and introduces two types of unidirectional and omnidirectional underwater wireless magnetic induction communication models.The relationship between the transmission characteristics of the coil,including eddy current loss,coil radius and operating frequency is simulated and analyzed.Secondly,aiming at the design of the communication coil,a mathematical model of the transmitting coil is established,and the optimal power distribution of the transmitting coil is analyzed.In view of the situation in which the receiving node is affected by water disturbance or the motion of the communication node in the underwater environment,the unidirectional coil and the omnidirectional coil are compared and verified by formula calculation,simulation data and experiments.The research results show that,The omnidirectional magnetic communication model can significantly reduce the influence of the direction change of the receiving end coil on the communication effect,and the volatility is reduced by 97.19%,and the communication stability is improved.Thirdly,the signal modulation and demodulation and path loss problems are analyzed,and the optimal modulation and demodulation mode is given and simulated.By simulating the eddy current loss of unidirectional and omnidirectional coils,the advantages of using omnidirectional coils for communication are further verified.Finally,an experimental design platform for underwater wireless magnetic communication is introduced in this thesis.The design adopts BPSK modulation technology and realizes signal transmission by means of the mutual coupling between coils.The test results show that the omnidirectional coil can effectively improve the stability of wireless communication and the feasibility of wireless magnetic communication system as an underwater communication application.The test communication rate is 212.5kbps,and the volatility is reduced by 95%.更多还原