| With the deepening of human understanding and exploration of the world,the ocean has become a new hot spot for the development of science and technology,and more and more countries have put their strategic eyes on the ocean.In order to make a more in-depth study of the ocean,the research of Underwater Unmanned Vehicle and underwater acoustic communication network technology has developed rapidly in recent years.Biomimetic robot fish has a great application prospect in marine research.To realize the cooperative work and information transmission of biomimetic robot fish in underwater environment,underwater acoustic dynamic networking and its communication protocol are one of the key problems.This thesis starts from the dynamic networking of biomimetic robot fish,and carries out the research work of underwater acoustic communication based on graph theory,involving the modeling of underwater acoustic communication node,MAC protocol design,routing protocol design and so on.The main research contents are as follows:Firstly,the background and significance of the research on the dynamic networking of biomimetic robot fish are described,and the research status of underwater acoustic communication networking,routing protocol and MAC protocol at home and abroad is summarized.The characteristics of underwater acoustic communication channel,the problems faced by networking and the main topology structure are pointed out,and the chapter structure and main content of the thesis are summarized.Secondly,the underwater acoustic communication network node of bionic robot fish is modeled.The model comprehensively considers the influence of water environment temperature,salinity,turbulence noise,shipping noise,sea surface noise,thermal noise on the transmission delay,propagation delay,receiving power and environmental noise between biomimetic robot fish,which is closer to the real underwater acoustic communication node.In order to clarify the difference between water environment and air wireless communication,the simulation experiments of air wireless channel model and underwater acoustic channel model are carried out,and the end-to-end delay and throughput between them are compared.Thirdly,a MAC protocol design method for underwater acoustic communication based on graph coloring theory is proposed.Due to the absorption loss of sound waves by sea water,the channel bandwidth of underwater acoustic communication is limited,the channel pressure of multi node underwater acoustic communication network is high,and the competition is fierce.Therefore,the undirected graph is introduced,and the coloring algorithm is integrated into the design of underwater acoustic communication MAC Protocol,thus the channel allocation problem of underwater acoustic communication network is solved through the graph coloring problem.Through the simulation experiments of MAC protocol communication with graph coloring algorithm and MAC protocol communication without graph coloring algorithm,the simulation results show that the graph coloring theory can improve the optimization of channel occupation of underwater acoustic communication of bionic robot fish.Finally,a routing protocol of biomimetic robot fish dynamic networking based on uncertain graph is designed.Considering the operation condition of underwater acoustic communication network and the characteristics of water environment shielding acoustic signal,the uncertain graph theory is introduced to realize dynamic routing.The k-CLOSE algorithm is introduced into the underwater acoustic communication routing protocol to find the tight subgraph in the uncertain graph.Due to the high probability of the existence of edges between nodes in the compact subgraph,the nodes in the compact subgraph are the most closely related nodes in the whole graph.Modeling and simulation experiments are carried out on OPNET platform.The simulation results show that the routing protocol based on uncertainty graph can improve the network performance. |
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