Research On Optimized Distribution Method Of Wireless Energy Based On UAV

Wireless Sensor Networks(WSN)is a wireless network composed of a large number of static or mobile sensors in a self-organized and multi-hop way.It is widely used in many fields,such as military,intelligent transportation,environmental monitoring,medical and health care and so on.Due to the development of Internet of things technology and the arrival of big data era,wireless sensor networks continue to evolve in the direction of large scale,multi-isomerization and so on.In the face of the increasingly complicated wireless sensor network,the problem of energy shortage around wireless sensor network has become more prominent.With the rapid development of small Unmanned Aerial Vehicle(UAV)and RF energy transmission technology,the UAV carrying RF energy sources flying or hovering over the WSN covered area can replenish the energy of the sensor nodes in the area,which provides a feasible scheme for the problem of energy shortage in wireless sensor networks.Hence,it is of great significance to study UAV assisted wireless energy transmission systems.We first construct the UAV-assisted energy supplement model for wireless sensor networks.UAV carries RF energy source to fly or hover over the wireless sensor network,and the sensor node has energy receiving device to receive the RF energy emitted by UAV,thus realizing WSN energy supplement.We discuss and analyze the wireless energy transfer problem in the model.1.We model the energy consumption of the WSN according to the type of sensor node,the communication protocol of the network,and get the WSN energy consumption distribution.Thus,we determine the proportion of energy required for each sensor node in the network.2.Due to the uncertainty of WSN deployment,it is not possible to determine whether the sight distance transmission is between the UAV and the node to be charged,so we propose a probabilistic Lo S model.3.At the energy receiving end of the sensor node,we give a nonlinear receiving model of quadratic polynomial according to the actual characteristics of the energy receiving device.Then we discuss how to optimize the flight trajectory of the UAV in a single UAV energy carrying scenario to maximize the energy obtained by the charging node in the WSN and satisfy the energy proportion distribution,and establish a mathematical model of the maximization problem.Because the problem is a non-convex optimization problem,the Lagrange dual method is used to analyze the problem.Then a continuous convex optimization algorithm is proposed to obtainthe optimal flight trajectory of UAV by continuous iteration.Experimental simulation results show that the proportion of energy obtained by the node and the proportion of energy consumption of the node have been achieved the desired effect.Finally,the wireless energy energy transmission system with UAVs,the area to be charged is divided into several sub-regions by combining the node and energy dissipation distribution of network.We establish the association of UAVs with sub-regions to coordinate the dispatch of UAVs for energy replenishment.And we present the comparison results of single and UAVs for large-scale WSN charging.Simulation results show that UAVs cooperative charging can meet the energy demand of large-scale WSN.When the number of UAV increased to 4,the charge energy increased 10 times than the single UAV charge energy.