Research On Multi-charger Energy Supplement Strategy In Wireless Rechargeable Sensor Networks

With the development of the Internet of Things,wireless sensor networks have been widely used in military,agriculture,medicine,monitoring systems and other fields.However,most sensor nodes are not equipped with large-capacity batteries for easy installation,and network performance is limited by the battery capacity of the sensor nodes.Therefore,the extension of network life cycle is one of the main challenges for wireless sensor networks(WSNS)under the energy constraint of nodes.Based on the demand for energy management of sensor nodes,wireless rechargeable sensor networks have emerged.Existing wireless energy supplement research mostly uses one mobile charger to serve the entire network,or deploys multiple chargers to cover all sensor nodes.However,a single mobile charger is not suitable for a large-scale network environment,and it is costly to deploy multiple chargers.Therefore,this thesis proposes to use multiple mobile chargers to supplement energy for sensor nodes in the network.The main contributions of this thesis are as follows:(1)Aiming at the one-to-one charging scheduling problem of multiple mobile chargers,a scheduling scheme combining cluster routing protocol and on-demand charging of multiple mobile chargers is proposed.First,the sensor nodes in the network are clustered to reduce the communication distance of nodes in the network,decrease energy consumption and balance the network load.Before the start of the charging cycle,mobile chargers are allocated to all nodes that send charging requests,and the charging path are optimized by the improved bee colony algorithm which considers both local search and global optimization.For real-time request nodes generated during the charging process,combined with the dynamic insertion method,emergency charging is arranged.Finally,from the length of the charging path,the total energy consumption of charging,the number of nodes that violate the constraints,etc.,the validity and feasibility of the algorithm proposed in this thesis are verified.(2)Aiming at the one-to-many directional charging scheduling problem of multiple mobile chargers,the directional mobile chargers with smaller charging loss are used to supplement the energy of the sensor nodes.According to the remaining energy of the sensor nodes in the network,the starting time of the charging task is determined,the charging subset with the greatest charging benefit is selected and the improved bee colony algorithm is used for charging scheduling.On the premise that the charging time and the battery capacity of the chargers are satisfied,the real-time request node generated during the charging process is inserted into the uncharged scheduling queue.Through experimental comparison and analysis,it is verified that the algorithm proposed in this thesis has superior performance in reducing the node failure rate and the total energy consumption of the mobile chargers.