Research On Data Collection And Charging Strategy In Wireless Rechargeable Sensor Network

Wireless Sensor Network(WSN)is a network consisted of numerous sensor nodes which perceive the outside world,it has been greatly developed and applied in recent years.However,the battery capacity of sensor nodes has become a constraint for WSN.When researchers transmit external energy to sensor nodes,such as solar,wind and tidal energy,the research of WSN is promoted to the research of Wireless Rechargeable Sensor Network(WRSN).With the development of science and technology,wireless energy transmission technology makes the life cycle of WRSN considerably extended.Therefore,wireless energy transmission technology is the key of WRSN,and it is also a hot research topic nowadays.However,data collection and charging strategies of WRSN are discussed separately in previous studies.With the increasing function of the charging vehicle,how to maximize the operational efficiency of the mobile charger,make the life cycle of the whole network longer,and the real-time of the data is worth further study.For data collection in WRSN,previous networks rely on single-hop and multi-hop mode to transmit the data perceived by each sensor node to the base station.Because of the multihop,sensor nodes need to calculate the multi-hop routing,which undoubtedly increases the energy consumption of sensor nodes.Most importantly,communication always consumed most of the energy of sensor nodes,so long-distance communication is not suitable for today's WRSN.In this thesis,we use mobile Sink to receive the sensing data of each sensor node.On the other hand,the path planning of mobile charger is always a hot topic in WRSN research.However,considering charging planning alone cannot meet the needs of this thesis.In order to cooperate with data collection and charging strategies in WRSN,in this thesis,the mobile charger can receive the sensing data of the surrounding sensor nodes while charging the sensor nodes.Firstly,sensor nodes scattered in the region are clustered by the hexagonal honeycomb clustering algorithm.When the mobile charger travels to the center of the regular hexagon,the mobile charger will serve the sensor node which needs to be charged in the regular hexagon.Because the communication distance is far greater than the charging distance of the mobile charger,all the sensor nodes in the regular hexagon can transmit the sensing data to the mobile charger in turn.Then,considering the remaining time and geographical position of sensor nodes,the priority of each cluster is calculated by RTGP algorithm,and we can get the charging queue.Finally,we use DMC algorithm to cut the existing charging queue to calculate the number of mobile chargers and the service route of each mobile charger.With the deepening of the research,we also studied the data validity of sensor nodes.On the premise of ensuring that all nodes do not die,we use DLS algorithm to update the charging queue calculated by RTGP algorithm.It can enable important nodes to transmit data to the charging vehicle in each charging cycle.At the same time,we use CLDMC algorithm to cut the new charging queue,it ensures that even if there is no sensor node to be charged for a long time,the base station will still dispatch a mobile charger for data collection.Finally,we do experiments on existing hardware devices,and use software simulations to compare the existing algorithms to evaluate the algorithms in this thesis.