Research On Key Technologies Of Mobile Node Localization And Target Tracking In Underwater Wireless Sensor Network

In recent years,the demand for Marine environmental protection and resource development and utilization is getting higher and higher.As one of the key technologies to explore and utilize the ocean,underwater wireless sensor network has also become a research hotspot.The location information of underwater sensor network nodes is one of the keys for the network to work effectively.The underwater environment is more complex than the land environment due to water flow and other factors,and due to the attenuation of the radio frequency signal in the underwater transmission is too large,it cannot be used for the medium and long distance transmission of underwater information,only the underwater sound can be considered.Therefore,the land wireless sensor network technology cannot be directly applied to the underwater sensor network.The main problems of underwater node positioning are as follows: firstly,the mobility of nodes is caused by water flow and other factors;secondly,there are holes and edge problems in the sensor network,which will lead to the inability of some nodes to complete the positioning.This will bring the whole network node positioning error,positioning coverage low problems.The sensor network can be used for underwater target tracking when the whole network is positioned.Since underwater nodes are mainly powered by batteries,in the case of no energy supplement,nodes will die once their energy is exhausted,which not only affects network coverage and performance,but also increases the cost.In practice,due to the difference of underwater environment,communication distance between nodes,and the different roles they play in the network,the overall energy consumption of the network is not balanced,and the network life is reduced.In view of the above problems,this paper studies the node location and target tracking technology of underwater wireless sensor network,and mainly completes the following work.(1)The structure model of underwater wireless sensor network are given.The problems of holes and edges in underwater wireless sensor network and their effects on node location and target tracking are analyzed.The node location and target tracking technology are discussed.(2)A mobile predictive location algorithm based on dynamic node selection is proposed.According to the difference of node density,the algorithm can effectively solve the network void and edge problem by dynamically selecting node strategy,and can well deal with the mobility problem of nodes by predicting the movement mode of nodes through the anchor nodes.The simulation results show that the algorithm can reduce the positioning error,improve the positioning accuracy and positioning coverage,and improve the reliability of the network.(3)A particle filtering target tracking algorithm based on energy balance is proposed.Aiming at the problem of high energy consumption and unbalanced energy consumption,the algorithm uses cluster head nodes to schedule up to four nodes at a time,and selects the appropriate nodes according to the remaining energy of nodes and the weighted sum of their distance to cluster head nodes.The simulation results show that the proposed algorithm can effectively reduce the energy consumption of each node,balance the energy consumption of the whole network and prolong the network life on the premise of ensuring certain tracking accuracy.