Research On Node Location Algorithm In Wireless Sensor Network

With the development of the Internet of Things(IoT)technology,the requirements of location information are getting higher and higher in practical applications.As a network technology with broad application prospects,Wireless Sensor Network(WSN)has been used in the fields of national defense security,data measurement and control,and intelligent applications.In practical applications,node location technology is the basis of many applications of WSN.When the node determines its own location information,the data carried by itself can exert its maximum application value.Ranging-based and Range-free-based positioning algorithms are two types of positioning algorithms commonly used in node location technology.How to improve the accuracy of the positioning algorithm and obtain the accurate node position has become the focus of node positioning research.Therefore,Selecting the node location algorithm in the Wireless Sensor Network as a research topic.This article chooses the DV-Hop algorithm of range-free positioning algorithm as the main research object.We design solutions by analyzing algorithm errors.Theoretical analysis combined with simulation results to evaluate algorithm performance.The specific research work is as follows:(1)Design of DV-Hop algorithm based on minimum mean square error.The uncontrollable distribution of nodes causes errors.In order to reduce the error and improve the positioning accuracy,a Minimum Mean Square Distance Vector-Hop Algorithm(MMSDV-Hop)is proposed.Firstly,determine the number of nodes based on the threshold,filter the nodes with better quality.Then,select the minimum mean square error criterion to obtain the single-hop of the beacon node.Moreover,the single-hop is corrected by the average single-hop error.At the stage of determined the single-hop of unknown node,the single-hop of the unknown node is determined by the weighting method of the node hop and the single-hop error as the weight.Finally,when determining the coordinates of unknown node,in order to distinguish the influence of different nodes on the coordinates,select a weighted least squares method with distance and hop error as weight.After the weighting process,it can output the coordinates closer to the actual position.Comparing the experimental error results,the MMSDV-Hop algorithm can reduce the average positioning error by 21.6% compared with the DV-Hop algorithm.(2)Design of positioning algorithm based on cuckoo search technology.Aiming at the low accuracy of the localization algorithm,the Cuckoo Search Technology Location Algorithm(CSTMDV-Hop)is proposed.In the stage where the MMSDV-Hop algorithm solves the coordinate position,the data error of the previous stage will be continuously introduced,and willbe multiplied in the subsequent calculation process.The continued accumulation of errors can cause deviations in the coordinate results.Aiming at this problem,designing a localization algorithm based on the cuckoo search algorithm,namely CSTMDV-Hop algorithm.It can transform positioning problems into intelligent optimization problems.At the same time,the key parameters are adjusted to improve the efficiency and accuracy of optimization.For the step factor,based on the difference of the optimal fitness function value between the current iteration and the previous iteration,Parameters can be adjusted;For the discovery probability,when the fitness function value of a certain iteration is obtained,compared it with the function value of all solutions from the previous iteration.It can added a probability parameter based on the degree of the solution,the discovery probability can be adjusted by this parameter.Comparing the experimental error results,the CSTMDV-Hop algorithm can reduce the average positioning error by 7.1% compared with the MMSDV-Hop algorithm.