Improved APIT Localization Algorithm In Wireless Sensor Networks

In the21st century, with the rapid development of the wireless communicationtechnology, embedded technology, computer technology and sensor technology, thetechnology of Wireless sensor network is especially noticeable. Wireless SensorNetwork(Wireless Sensor Network，WSN), as a new network technique monitoringthe Target Area in complex environment, with the ability of perceiving, collecting data,transferring, and processing target object data, is widely used in a number variety ofaspects such as military, medical treatment, transportation, environmental monitoring,constructional engineering and so on. The data information collected by wirelesssensor node is valuable only when they combine with the position information.Because of the randomness of wireless sensor node deployment and limitations ofnode, mature GPS is not suit for WSN, so it has presently been a hot issue of WSNnode localization research to excogitate a localization system or algorithm which issuit for WSN with high accuracy, high coverage and low power consumption oflocalization.APIT (Approximate Point-in-Triangulation Test) localization algorithm hasalways been the focus of the research of WSN node localization. This paper deeplyexplores APIT localization algorithm aiming at the problem of relatively lowprecision of location accuracy, and puts forward two improved APIT localizationalgorithms-Improved APIT location algorithm based on RSSI (Received SignalStrength Indicator)(RSSI-IAPIT) and Improved APIT location algorithm based onmobile anchor node (MA-IAPIT). The former algorithm, which is based RSSI,combines the energy loss in the procedure of wireless signal broad and anchor nodelocation coordinates to figure out the estimation of location of the unplaced nodes; thelatter one assigns neighbor anchor node a certain offset, and use the average centerposition as the estimated location of the node.In order to compare the localization performance of APIT location algorithm andtwo improved algorithm and analysis them, experiment on Mat lab has been carriedout in this paper, the results show that localization precision of the two improvedalgorithm are better than the APTI location algorithm’s, which improve the systemapplicability of localization algorithm.