Research On Charging Strategy Of Wireless Rechargeable Sensor Networks

With the application of wireless sensor network more and more widely,the information that nodes receive and transmit becomes more and more complex,and the energy problem of sensor nodes becomes more and more prominent.Wireless rechargeable sensor network can replenish energy for sensor nodes by deploying wireless charging vehicles in the network,so as to prevent nodes from failure due to energy exhaustion.The efficient charging strategy can make the wireless charging vehicle obtain the maximum network utility with the minimum charging cost.We need to design the charging strategy of the network reasonably,so that the network can run stably and permanently.This thesis studies the charging strategy of wireless rechargeable sensor network from the following two aspects:Firstly,an energy-aware anchor point selection strategy is proposed to minimize the charging time for the periodic one-to-many charging network.In the process of anchor point selection,the location relationship between sensor nodes is considered,and the number of neighbor nodes of each node is determined according to the charging radius.The nodes with the largest neighbor nodes are clustered preferentially to ensure that the nodes in the cluster can be charged at the same time.The charging time in each cluster depends on the energy consumption power and charging power of the nodes in the cluster.In order to shorten the charging time,the ratio of charging power and energy consumption power is taken as the optimization objective when selecting the anchor point,and the location of the anchor point in each cluster is solved by genetic algorithm.The simulation results show that the charging time is shorter and the network energy consumption is lower compared with the traditional anchor point selection strategy based on hybrid clustering.Secondly,a joint routing and charging strategy is proposed for the energy limited wireless charging vehicle network.An optimization problem is established to maximize the energy of the sensor nodes with the lowest residual energy in the network.In order to solve this problem,it is necessary to determine the energy consumption and charging power of nodes in each charging round,so a joint selection strategy of anchor point and cluster head is proposed.At the beginning of each charging round,the nodes in the network are firstly clustered based on the charging radius to ensure that the nodes in the cluster can be charged at the same time.Then the anchor point is determined according to the energy consumption center of the nodes in the cluster,and the cluster head is selected according to the anchor point and residual energy of the nodes in the cluster.In the scheme,the energy constraint of the charging vehicle is considered and partial charging is applied.By optimizing the charging time of each anchor point,the goal of prolonging the network life is achieved.The simulation results show that the proposed joint charging strategy has a longer network lifetime than the traditional energy limited charging strategy based on the grid center.In conclusion,the charging strategy proposed in this thesis can effectively improve the charging efficiency and reduce the energy consumption of the network,which can ensure the network run stably and permanently.The strategy provides theoretical support for the future research of charging strategy and has certain research value.