Indoor Location System Design Based On Zigbee Network And Applications In Hospital

With the development of wireless communication technology, people pay more andmore attention to location technology, and it's no doubt that GPS is currently the most widelyused location technology. The location requirement is not only confined to the outdoorlocation, indoor location, which has more and more application requirements especially inhospital, large buildings and other security aspects. Because of the limitation of GPS systemin indoor location field: That GPS signal is susceptible to buildings causes significantly signalstrength decreased, and its location accuracy is decreased or even unable to work. How torealize the precise location in complex indoor environment is a big problem indoor locationtechnology need solve.This paper has researched and discussed the indoor location system covering all therelated key technology, put forward and designed a wireless indoor location system which isbased on ZigBee wireless sensor network technology, indoor location geographic informationconstruction technology and improved method of the weighted centroid algorithm, and thesystem can effectively realize the accurate location in complex indoor environment, and it isin support of the hospital internal real time positioning and track playback.The main contribution of this thesis and innovation include such four respects as below:Firstly, this paper has studied and designed an indoor location geographic informationconstruction method. According to the results of AutoCAD paper analysis, geographicinformation spatial data is analyzed and coordinate transformed, build an indoor geographicinformation data base to store the data which is transformed, and then display to client in theway of electric map through the real-time indoor location data display module. In theory,spatial information comprehensive and instant acquisition is achieved, and the locationaccuracy of data display is improved in using geographic information technology.Secondly, this paper has studied the traditional RSSI centroid algorithm, and put forwardan improved algorithm based on traditional algorithm. The experiment has showed that thealgorithm has higher accuracy than the traditional centroid algorithm, and the error of traditional triangle centroid algorithm tends to be constant with the increase in the number ofanchor nodes, while the error of weighted centroid localization algorithm becomes more andmore accurate.Thirdly, the system is realized in the way of combing hardware and software. Thecombination of8051single-chip computer and CC2430/CC2431chip is used in the term ofhardware, and has built a hardware platform of ZigBee wireless sensor network. The platformis mainly made of three major components which are ZigBee sensor network module, dataservice module and external system interface module. In the term of software, the system isdeveloped using C#language programming, and analyzes hospital AutoCAD maps in usinggeographic information construction methods which include AutoCAD map analysis,geographic information storing and real-time location information display and so on. At thesame time, calculate the location coordinates of the object data information in using centroidalgorithm and display the real-time track on electric map to achieve real-time positioningeffect.Fourthly, the system designed in the paper is based on practical application in hospital.And performance test of the system has been done basing on realization of the basic indoorpositioning function. The experiment has showed that the system has a higher detection rate,low false alarm rate and faster detection speed. It can not only achieve satisfactory real-timepositioning effect, but also track playback effect is more reliable and the system can well meetthe indoor positioning accuracy and real-time requirements. The system can be widely usedfor the internal hospital medical staff, materials and patients real-time location, real timecontrol of medical staff's physical location, realize hospital medical staff scheduling, materialmanagement and patient monitoring, improve the comprehensive management efficiency andoptimize management process.