Research On Improved Algorithm Of APIT In Three-dimensional Positioning Method

Wireless Sensor Network (WSN) is a wireless ad hoc network that the sensor nodes arearranged in the monitoring region. The data information is collected and processedaccordingly. When the sensor nodes are in an no man’s land, they capture the changinginformation by wireless communication for the practical purpose. With the fast developmentof modern information technology, WSN has been widely used in fire, mine detection,logistics monitoring, military operations, environmental monitoring and so on, which not onlyprovides a lot of convenience, but also brings people multivariate changes in the society.Through developing in different areas, it researches on uploading parameters in the actualenvironment, which provide the appropriate scheme for people. It analyzed the characteristicsof context that the location information as important as context information is led. Accuratelocalization of the position information has become scholars focus on one of the importantproblems at present.APIT (Approximate Point-in-Triangulation Test) algorithm is one of the popular locationalgorithm in the present. As one of the key technology in WSN, it requires higher nodeconnectivity. Although mistakes easily lead to wrong positioning, it has higher efficiency andprecision more than others. the communication expense is lower and suitable for sensorwithout enough resource. This paper studies on the basic architecture and the main problemsof APIT location algorithm, and discusses three-dimensional localization algorithm.Then itdetailed discuss the application and shortcoming of APIT location algorithm inthree-dimensional space. The APIT positioning algorithm is improved with thethree-dimensional space that by the value of RSSI comparing the distance from unknownnodes to anchor nodes and neighbor nodes and judging the position of the unknown nodes,then estimating the estimated position of the unknown node in multiple tetrahedral overlapregion by the centroid algorithm of the sphere. It reduces the misjudgment which is led byedge effects cause and reduces the positioning errors, then the original algorithm is optimized and improved.Analysis of the environmental parameters of the APIT-3D location algorithm and theimproved APIT-3D algorithm. by using the MATLAB software platform as the positioningtool to emulate the coverage rates of positioning and the average positioning errors about thetwo algorithms. The results show that the improved algorithm is higher than that of APIT-3Dalgorithm in positioning accuracy and the algorithm in practical application is improved.