| The monitoring function of wireless sensor networks is widely used in various fields,and the monitoring function needs to be based on the known location information of each network node,while the location of unknown nodes involves the node location algorithm.This thesis will mainly optimize the DV-Hop location algorithm,which is the most widely used location algorithm without ranging.This algorithm is widely used because its location cost is lower than other algorithms.However,the application scenario of the algorithm is limited to two-dimensional plane,and the positioning error is large.In the actual positioning process,the positioning scenarios are mostly three-dimensional space areas,and the positioning error and positioning cost are high.Therefore,this thesis will build a 3DDV-Hop positioning algorithm based on three-dimensional space,and make the following optimization improvements with the goal of reducing the positioning error and positioning cost of the algorithm:1.In order to solve the problem that there are errors in calculating the minimum hop count and average hop distance between unknown nodes when DV-Hop localization algorithm calculates the distance between unknown nodes and anchor nodes,this thesis proposes a 3D-DVHop localization algorithm based on hop count weighting and hop distance optimization.The algorithm corrects the minimum hop count of adjacent nodes according to RSSI value,and corrects the average hop distance between anchor nodes by constructing hop count weights,so that the spatial straight distance between unknown nodes and anchor nodes can be improved.2.In order to solve the problems that DV-Hop localization algorithm does not combine the node communication radius in the process of correcting the minimum hop count between adjacent nodes,and does not correct the coordinates of unknown nodes after obtaining the coordinates of unknown nodes by maximum likelihood estimation,this thesis proposes an improved 3DDV-Hop localization algorithm based on three-dimensional coordinate correction.This algorithm corrects the minimum hop count between nodes by setting the node communication radius by classification,so as to achieve the purpose of further optimization of the hop count correction method,and corrects the coordinates of unknown nodes by constructing cube intersection areas.3.In view of the high proportion of anchor nodes in various improved DV-Hop positioning algorithms,this thesis proposes a 3D-DV-Hop-ACR positioning algorithm based on virtual force moving anchor nodes.Based on comprehensive consideration of optimized hop count,hop distance correction scheme and unknown node coordinate correction method,this algorithm introduces virtual force gravity to transform static anchor nodes into dynamic anchor nodes,and periodically communicates with nodes within its communication range during the moving process,thus reducing the proportion of anchor nodes needed and achieving the positioning cost. |
