| Underwater target tracking technology,as the critical technology support for exploiting and utilizing marine resources and defending and protecting marine safety,is one of the important research directions in ocean engineering.Target tracking based on Underwater Wireless Sensor Network(UWSN)has the advantages of large breadth,long monitoring time and real-time data merge,so it has become a new hot spot for research.Because of the complexity of the underwater world,the accuracy of measurement data obtained by nodes and target tracking will be affected.Anyway,the energy stored by underwater sensor nodes is limited,and once used up,it will be difficult to charge or replace them.Therefore,how to improve energy efficiency and achieve a equilibrium between tracking precision and energy consume is the main direction of research on UWSN based target tracking algorithms.This paper designs target tracking algorithms from the perspectives of node height adjustment and node energy allocation to improve the energy efficiency of UWSN target tracking.The main research elements of this paper include the following:The sparse deployment of UWSN nodes can result in missing measurement data,and nodes can move in the height direction to dynamically adjust the deployment structure between nodes and obtain more complete measurement data as much as possible.In this paper,a node height regulate target tracking algorithm considering the node’s mobile energy consumption is proposed.Firstly,in order to evaluate the value of node measurement information,a ration relationship among the Post-checking Cramer-Rao Lower Boundary(PCRLB)and node height variation is established;then different optimal node height solutions are given for the cases where the target height is known and unknown respectively;finally,a dynamic coefficientβis introduced to regulate the weight between target tracking accuracy and energy consumption.Through simulation experiments,the algorithm in this paper can improve tracking accuracy by about 32.03% and 23.64% when the target height is known and unknown,respectively.Compared with the node height adjustment algorithm that does not consider mobile energy consumption,it reduces node mobile energy consumption by about 69.37% and 66.52%,respectively.The energy and measurement information value of each node in UWSN are constantly changing,and the value of measurement information can be evaluated first,and then more reasonable energy allocation can be made for measurement data of different values.This article proposes a target tracking algorithm based on optimal decision energy allocation.This algorithm first calculates the quantitative relationship between node energy consumption and Fischer Information Matrix(FEM)over a period of time,and then establishes an objective function based on the value of measurement data,allocating more energy to process high-value measurement data.It is difficult to directly solve the optimal solution of energy allocation at each time.This algorithm uses dynamic programming to obtain the optimal energy allocation scheme by establishing a Markov decision process.Through simulation experiments,compared to the allocation algorithm that does not consider the original energy constraints of the system and the algorithm that distributes energy evenly,the algorithm proposed in this paper can improve tracking accuracy by about 19.34% and5.3%,and has good tracking performance at low energy collection efficiency. |
