Research On Multi-Objective Optimization For Joint UAV-AGV Collaborative Beamforming

The sensor nodes in traditional wireless sensor networks are often limited by resources,energy and transmission range,so the establishment of mobile wireless sensor networks has been paid more and more attention in improving the quality of network communication.Automated Guided Vehicle(AGV)has the advantages of agility,long standby time and strong controllability,so it is often widely used in program monitoring,sensor network and other scenarios.However,AGV is limited in flexibility,moving speed and propagation range,which leads to some limitations in the application scenarios of AGV.Unmanned Aerial vehicle(UAV)is a promising platform with the advantages Of high flexibility and high line of sight(Lo S),which can be equipped with intelligent decision making capabilities to perform tasks autonomously.The goal of this thesis is to use the high flexibility of UAV and the high persistence of AGV to establish a UAV-assisted AGV wireless sensor network to forward data.Specifically,this thesis uses distributed cooperative beamforming(DCB)technology,and proposes a novel data transmission framework that UAV assists AGV to construct antenna array to transmit data.In order to enhance the performance of wireless sensor network,sensor nodes need to move to positions with optimal excitation current weights to form highly directional beams.However,UAVs and AGVs will cause extra energy consumption in the process of movement.In order to enhance the performance of the wireless sensor network composed of UAVs and AGVs,this thesis takes reducing the data transmission time of the wireless sensor network,the forming time of array antenna(VAA)and the energy consumption between AGV and UAV as targets,and constructs a multi-objective optimization problem.This thesis proposes solutions for two different scenarios:1.For a scenario without any obstacles between the data sender and the data receiver,this thesis uses the UAVs to assist the AGVs to build a VAA to communicate with the remote air base station(ABS).Since the data transmission process will not be affected by multipath,the data transmission is simulated based on Lo S channel model.This thesis formulate a multi-objective optimization problem for cooperative data transmission over land and air TATFMOP to reduce the data transmission time,VAA formation time and the overall energy consumption of UAVs and AGVs.Since TATFMOP is an NP-hard problem,this thesis proposes an improved multi-objective ant lion algorithm EMOALOIB to solve TATFMOP.EMOALOIB algorithm enhances the performance of MOALO by using the idea of opposition-based learning(OBL)and black hole updating(BH).The experimental results verify the effectiveness of the proposed algorithm and prove that it has better performance in solving the TATFMOP problem.2.For the scenario where UAVs assists AGVs to form VAA to communicate with ABS in a complex environment.Considering that DCB technology can be applied in some complicated terrain areas,such as trees,hills and mountains,which will affect the quality of communication links.What’s more,this thesis explicitly proposes three optimization objectives based on the probabilistic Lo S channel model,that is,reducing the communication time between wireless sensor networks and different ABSs,the total time for UAVs and AGVs to form VAA,and the energy consumption of mobile nodes.In addition,this chapter also constructs a multi-objective optimization problem PLFMOP for UAV-assisted AGV to forward data.This problem is also NP-hard,so this thesisproposes an improved MODA algorithm PGIMODA to solve it.The experimental results verify the effectiveness of the PGIMODA and prove that it has better performance in solving the PLFMOP problem.This thesis proposes an innovative wireless sensor network framework that fully utilizes the highly flexible features of UAV and low energy consumption of AGV,achieving efficient,flexible,and reliable data transmission.In traditional wireless sensor networks,the quality and efficiency of data transmission are often affected due to the limitations of resources,energy,and communication range of nodes.However,this framework can partially solve these problems.The sensor network consists of two parts:UAVs and AGVs.The UAV is responsible for carrying the data transmission equipment and using its highly flexible features to forward data to the AGV in the air.The AGV runs on the ground,receives and stores the data transmitted by UAV.Both UAV and AGV work together through DCB technology to accomplish data transmission tasks,providing new ideas and methods for research and application in the field of wireless sensor networks.