Algorithm Wireless Sensor Node Localization

Wireless sensor network is a novel network which supported by the high technology andits function not only strong, but also complete. Node localization technology as its basic ifeldsand the researchers pay attention to it. In recent years, through domestic and foreignresearchers’ In-depth study of it, so many related algorithms has been improved and putforward. In order to have a better understanding the positioning performance of the positioningalgorithm, the researchers analyzed and discussed on its performance with the variousevaluation standards. But the location of nodes in the performance of the limited, thecomplexity of the environment, the dynamic changes of the network and a series of problems,so node localization of the wireless sensor network can not use to large scale application.Localization algorithm as the core part of the positioning technology, we need to furtherresearch on it. Within the scope of the positioning accuracy, Algorithm is needed to reduce thecomplexity of the operation and location of energy consumption.The research work and innovations of this paper:In this paper, four important ranging technologies and three ranging algorithms has madethe detailed introduction. Based on the various technology and algorithm analysis, introducesand compares advantages and disadvantages of the related technologies and algorithms.Paper focuses on the researching several important range-free localization algorithm to dothe related introduction, analysis, simulation and comparison. The simulation experiment ofcentroid algorithm shows that: the positioning accuracy of the algorithm is affected by thedensity of beacon node，the distribution of beacon nodes and the relative position of unknownnode (center or network edge). APIT algorithm is an improved centroid algorithm, Using thealgorithm to locate the unknown nodes，the performance will be better than other algorithms.Compared with other algorithm, the algorithm positioning precision of APIT algorithm is high，the algorithm positioning of the stability is better. In APIT positioning, some nodes may not beable to achieve positioning, some nodes may misjudge in APIT test and these factors will affectthe overall positioning accuracy. The main reason is that in APIT positioning can not be perfectrealization of PIT test; it is mainly the use of APIT test which similar to PIT test principle. Byusing the angle measuring method to replace the APIT testing method, solves some problemsrelated to APIT, so the algorithm improved. Describes the principle of DV-Hop algorithm andAmorphous algorithm, using the related software to realize the simulation experiment ofDV-hop and analysis of the performance of DV-Hop algorithm.According to some related problems of several range-based localization algorithms, Referto the position of base station3D direction-ifnding method, Based on location technology can complete the relevant measurement, Integration of the relevant knowledge; design a new kindof localization algorithm which is use the triangular geometry knowledge to achieve nodelocalization. On the base station3D direction-ifnding algorithm, the algorithm needs to measurethe elevation and azimuth angle which are related to the unknown node. But ranging sensortechnology can not realize measurement of elevation which is related to the unknown node. Inorder to achieve similar positioning method, we can measure the two angles which are relatedto the elevation. Using the cosine theorem to calculate the angle which is associated with thephase angle, and when you know the elevation and azimuth angles, calculation using thecoordinates of corresponding nodes to complete the corresponding coordinates. Analysis of theexperimental results obtained that the triangular geometry algorithm can achieve highPositioning accuracyIn order to get more data which is associated with the unknown node locaiton,Comprehensive use of resources, combined with the centroid algorithm to improve the originalalgorithm. The simulation results of the improved algorithm showed that: the algorithm’saccuracy has been further improved. When the density of beacon nodes is small, the improvedalgorithm still can achieve high positioning precision, and the computation of improvedalgorithm is less, it is suitable for the occasion which the density of beacon nodes is small andthe positioning precision is high.