Research On Node Localization Algorithm Based On DV-Hop For Wireless Sensor Networks

Wireless Sensor Network(WSN)technology has been a hot research field in the world,and it has important application prospects which has been widely used in military,environmental monitoring,industry and agriculture and many other areas.These applications require node location information,the wireless sensor network nodes location provides the necessary foundation for these applications.DV-Hop algorithm is an important method in node localization algorithm,the algorithm can obtain the location information of the target node.In this thesis,the research of DV-Hop algorithm is carried out and the DV-Hop algorithm is improved.The research mainly includes the following several aspects:Firstly,this thesis introduces the basic theory of WSN,typical rang-based algorithm,range-free algorithm and the unknown node position calculation method.Meantime analyzes the performance evaluation criteria of positioning algorithm.Secondly,the principle of DV-Hop algorithm is introduced,the steps of the algorithm are analyzed in detail and the error analysis is done.The DV-Hop algorithm is simple and does not require additional hardware equipment,but susceptible to the influence of network topology and unknown node location estimation algorithm.In order to optimize the positioning accuracy,the Particle Swarm Optimization(PSO)is used,however PSO algorithm is easy to fall into the local optimum,a modified particle swarm optimization(MPSO)algorithm is proposed in this thesis.On the one hand,the algorithm adjusts the parameters to improve the search ability.On the other hand,the algorithm sorts the particles to make the interaction between particles and increase the diversity of particles in the population,all of these can improve the algorithm performance.The simulation results show that the MPSO algorithm proposed in this thesis can improve the coverage and precision of DV-Hop algorithm effectively.Finally,a DV-Hop algorithm based on the connectivity difference between nodes is introduced,and the algorithm is improved.The improved algorithm corrects the average distance per hop,and gives the optimal combination of anchor node selection strategy and position calibration criterion.Then,based on the advantages of the improved connectivity difference between nodes and the advantages of MPSO algorithm,a DVHop localization algorithm based on improved connectivity between nodes and MPSO is proposed.The improved connectivity algorithm among nodes provides a relatively accurate position for the MPSO to initialize the population,improves the convergence speed,and improves the positioning accuracy for the DV-Hop algorithm.The simulation results show that the proposed algorithm can improve the convergence speed and positioning accuracy.