Research On Indoor Location System Based On ZigBee Technology

With the rapid increase in data traffic and the development of networkingtechnology, people increase the demand to care about the goal of monitoring,positioning and navigation, especially in complex indoor environments, such asfactories, showrooms, mines, storage, underground parking, etc. the relevantpersonnel and facilities in the indoor position information often needed to determine.But the condition is limited by the complexity of the indoor environment, positioningaccuracy and positioning time, currently recognized as the most outstanding indoorpositioning algorithm has not been generated.So develop indoor positioning systemwith a low-cost, high positioning accuracy, simple and good robust for wireless sensornetworks has become a research hotspot.This paper begins with an overview of the status and development trend ofdomestic indoor positioning system, after comparing common indoor wirelesspositioning technology, choose ZigBee technology as the development of the systemof wireless location technology, On this basis, through the study of the present severallocation algorithms comparison, selected based on received signal strength indicationconvenient (RSSI) localization algorithm.Aiming at the problem of inaccurate RSSIranging process due to environmental interference, this paper presents an algorithm ofweighted compensation of positioning error of coordinate after taking into account theenvironment similar feature between reference node and blind node. The algorithmfirst selects the suitable three reference nodes to calculate the preliminary estimatecoordinate of blind node by using the signal propagation loss model and theintersection of centroid method, then getting three groups coordinate error byreference nodes location each other. Finally, as coordinate error weighted to the blindnode coordinate, getting the ultimate estimate coordinates of blind node. Simulationresults in MATLAB show that this algorithm can effectively improve the positioningaccuracy，and choose a different reference range has different positioning accuracy.Then, for each node is designed in ZigBee2006protocol stack, and tested in theCC2430/2431node hardware platform, verify the feasibility and reliability of thesystem. Finally, summarize the full text, and to follow-up work is prospected.