Research On UAV-Assisted Data Collection Algorithm In Wireless Sensor Networks

Due to the rapid development of Internet of Things(IOT),Wireless Sensor Networks(WSNs),as a key supporting technology,continue to receive great attention.In large-scale WSNs,tens of thousands of energy-constrained sensor devices or nodes are randomly deployed in remote areas for monitoring information,which brings a great challenge for the energy-saving data collection task of WSNs.In addition,before the data collection task,it is necessary to obtain accurate sensor node coordinates information in advance;otherwise,the data collection task will be meaningless.To solve the above-mentioned node localization problems and energy-saving data collection problems,this thesis introduces Unmanned Aerial Vehicle(UAV)into WSNs and proposes a UAV-assisted node localization algorithm and a UAV-assisted sleep scheduling algorithm for energy-efficient data collection.The research contents of this thesis are summarized as follows:(1)Aiming at the node localization problem,based on the Received Signal Strength Indication(RSSI)technology,this thesis proposes a UAV-assisted Node Localization(UAVNL)algorithm.In this algorithm,the UAV is used as a movable anchor node to provide relatively accurate localization information,and the algorithm further improves the node localization accuracy by updating the RSSI reference values of the corresponding area and the three-dimensional maximum likelihood estimation method.Furthermore,in this thesis,we also propose a new MBO-TSP algorithm for UAV path planning.The simulation results show that the proposed UAVNL algorithm can improve the node localization accuracy and achieve fast localization when the total system energy consumption is small.(2)Aiming at the energy-efficient data collection problem,this thesis proposes a UAV-assisted Sleep Scheduling(UAVSS)algorithm for energy-efficient data collection,which can minimize the energy consumption of ground nodes and prolong the network lifetime.After the UAV obtains the coordinates of the redundant node and the working node according to the node sleep scheduling algorithm,according to the current working node coordinates,the UAV path is planned by the MBO-TSP algorithm,and the UAV will move along the path to collect the data of the working node.After completing the data collection task,the UAV will activate the corresponding sleep node to maintain network coverage.In addition,before using the MBO-TSP algorithm to calculate the UAV path,we optimized the coordinates of the current working nodes and obtained the coordinates of the new data collection points.After the coordinate optimization scheme,the calculation burden of the UAV path can be reduced by nearly 50%,and its length can be shortened by nearly 30%.The simulation results show that the proposed UAVSS algorithm for energy-efficient data collection can achieve a longer network lifetime while ensuring network coverage.