Research On Charging Scheduling Method Of Large-scale Wireless Sensor Network

The rechargeable sensor network is one kind of the sensor network,in which sensor node is rechargeable when the energy of the node is insufficient.There are various ways to charge sensor nodes.One way is to collect surrounding energy such as solar energy,wind energy,etc..However predicting the energy harvesting rate is tremendous hard due to the temporal and spatial changes of renewable energy which brings great uncertainty to the persistency of the whole network.With the development of magnetic resonance coupling technology,utilizing mobile chargers to supplement the energy of nodes has become the most popular way.When the scale of the network becomes larger,it is not enough to charge all the sensors in the system either by one-to-one charging mode or via a single charger.At the same time,the charging delay is very high,which is determined by the limited battery power and moving speed of the charger.Besides,if the movement speed of the charger becomes too fast,huge energy loss during the movement of the charger will inevitably reduce the energy utilization rate.In this dissertation,the problem of maximizing the energy utilization rate is studied in a large-scale wireless rechargeable sensor network.Based on the multi-car charging model and the relay multi-hop charging model,a mobile scheduling optimization method for chargers is proposed.The main research work of this article is as follows:(1)The multi-car charging model based mobile charging optimization scheduling strategy is studied.The optimization goal is to maximize the energy utilization of the mobile charger under the condition of the continuous operation of the wireless sensor network.To solve this problem,this dissertation first defines the virtual coordinates of the charging task of the charger.The virtual coordinates are used as the basis for the node charging task to be assigned to the charger,and the energy utilization problem is converted to the shortest distance problem with the virtual coordinates.Secondly,to increase the number of nodes in a single charging round,this dissertation defines high-efficiency nodes by judging whether the extra path ratio brought by the nodes is less than ?.By adding high-efficiency nodes,the energy utilization rate is further improved.Next,using the queuing theory to analyze and evaluate the performance of the proposed algorithm.Finally,experiments show that the scheme in this dissertation has competitive performance in terms of energy utilization,charging delay,and the number of dead nodes.(2)The relay multi-hop charging model based mobile charging optimization scheduling strategy is studied.The optimization goal is to maximize the energy utilization rate of the mobile charger under the condition of continuous operation of the wireless sensor network.To solve this problem,this dissertation first divides the sensor node level according to the number of sensor nodes covered in the relay range and the distance between the charger and the node and selects the relay node.The stopping point of the charger is determined via the relay node position according to its level.Secondly,all the stops are planned based on the Hamilton loop to move the charger,and the complexity of the proposed algorithm is theoretically analyzed and evaluated.Finally,the results of simulation experiments show that the proposed scheme improves the energy utilization rate by about 15%?25%,and has a good effect in large-scale sensor networks.