Research And Improvement On Range-free Localization Algorithm For Wireless Sensor Networks Based On Differential Evolution Algorithm

Wireless Sensor Network has been widely used in many fields and brought great convenience to people's lives.As an important technology in wireless sensor networks,node localization technology has become a hotspot of research.According to the positioning mechanism that needs to measure the distance between nodes,the node positioning technology can be divided into range-based and range-free positioning algorithms.The range-free positioning algorithm has advantages in hardware cost and complexity.Therefore,this paper focuses on the DV-Hop algorithm which is the classical range-free algorithms.The content mainly consists of these aspects:1.The research background,development history,and key technologies of wireless sensor networks are briefly described.Several typical range-based and range-free positioning algorithms,and common calculation methods in node positioning are also introduced.2.The reasons for the positioning error of DV-Hop algorithm are analyzed.This paper proposes a DV-Hop algorithm based on the differential evolution algorithm,which changes the traditional matrix equation Ax = b from the process of solving unknown node coordinates to the process of population optimal solution.Aiming at the problem that the traditional differential evolution algorithm is easy to fall into a local optimum at the later stage of the algorithm,and the obtained solution is significantly different from the actual solution.Two important parameters like scaling factor F and crossover operator CR are improved to further optimize the differential evolution algorithm.Simulation experiments were performed on the MATLAB platform to evaluate the improved algorithm from three aspects: node density,anchor node density,and communication radius.The simulation results show that the improved algorithm has improved positioning accuracy.3.An improved DV-Hop algorithm based on multiple communication radius and position correction is proposed.This paper analyzes the ranging error caused by the uneven distribution of network nodes,and introduces multiple communication radius to modify the minimum hops to optimize the average distance per hop.Aiming at the existent of local optimization problem in differential evolution DV-Hop localization algorithm,the position of the localized nodes is modified.The improved algorithm simulation is still analyzed from three aspects which are node density,anchor node density and communication radius,and the positioning accuracy is improved.