Research On Node Selection And Localization Optimization Algorithm In Cooperative Localization

With the rapid development of wireless sensor technology,wireless sensor networks(WSN)are widely used in agriculture,industry,military,transportation,communications and other fields.WSN becomes one of the important ways of the information perception,acquisition,processing and transmission.Node location technology is the key technology of wireless sensor networks applications.Node cooperation can solve the location problems arising from low sensor node power and insufficient nodes,but a large number of information exchanges between cooperation nodes will cause the increase of computational complexity and waste of energy,and even cause the positioning error increases.To solve these problems,this dissertation studies the method of node location technologies,optimize the node selection algorithm and improve the method of node localization.The detailed work is divided into two parts:The first step is to obtain the secondary nodes set by node selection algorithm.When signal model is established,we can obtain the test distances between neighboring nodes and the target node by the measured RSSI data.Then,we calculate the SPEB after deducing and updating the EFIM.By combining EFIM and distances to a new node selection criterion,a node selection algorithm based on EFIM and distances collaboration is proposed to select nodes with better positioning performance as a collection of the secondary nodes set.Simulation results show that the proposed algorithm can select the minimum number of neighbors to achieve the specified positioning accuracy,while improve the utilization rate of energy.The second step is to estimate the coordinates of the target node based on the secondary nodes.First,take the selected secondary nodes as the reference nodes,introduce a modified coefficient m,and then take the sum of the m power of the reciprocal of each measured distance as the modified weight.Second,compute intersection points of each circle with referenced nodes as the center and the testing distance as the radius of circle,and select the True Intersection Points(TIPs)according to the selection criteria.Finally,the weighted centroid of the polygon will be obtained by TIPs and modified weight.The method can help to spare the effort of setting up additional hardware devices,reduce massive information exchange and simplify complex coordination between the target node and reference nodes,thus meeting the application requirements of wireless sensor networks.The simulation results prove that the proposed algorithm is feasible to a certain degree.