Design And Implementation Of Indoor Positioning And Navigation Subsystem

With the popularity of Internet and the rapid development of mobile intelligentterminal, location-based service (LBS) has gradually penetrated into all areas of society,playing an increasingly important role in people’s daily life. In terms of daily life, such asshopping, tourism, logistics management and transportation scheduling, LBS can provide aconvenient service of location and tracking and navigation for users. One of the core featuresof LBS is location. Currently, the most commonly used positioning technology is GPS(Global Positioning System, GPS), However, due to GPS using satellite signals thatpropagates complex and is vulnerable to be effected by the obstacle, so the effect is not idealin indoor location, that makes indoor positioning technology develop fast and have been astrong complement to GPS positioning.Against the actual demand for positioning and navigation exhibition center, the paperdesigned and implemented the subsystem of positioning and navigation subsystem indoorsystem of exhibition center based on NFC+WiFi. Subsystem is mainly divided into twomodules: navigation service module and back office management module, Navigation servicemodule is the core module of the system.Navigation module is subdivided into two key modules: positioning and navigation.Positioning mainly used to locate the position of the fingerprint technique, whose ideas issimilar to the fingerprint identification technology in biometric fingerprint technology infingerprint identification technology.Firstily, establishing the AP signal strength of eachsample position as a fingerprint sample database, Secondly, acquiring the mobile terminal APsignal strength of the current position, finally, matching fingerprint sample library of samplesto estimate the current location of visitors.In order to effectivily making up the defect of WiFi indoor positioning, the paper using NFC tag technology, by matching the labelhe with the actual location of the database,enabling precise position, in a timely manner to correct the deviation of the position, improvethe positioning accuracy. Navigation mainly uses Dijkstra algorithm to find the shortest pathbetween two points, Due to Dijkstra algorithm in the search process will search no relatedpoints, resulting in a lot of time overhead, we use a rectangular area to restrict search area toimprove the Dijkstra algorithm, thus greatly improving the search efficiency, effectivelyreducing the search time. In the positioning and navigation subsystem, the entire mobile clientand server exchange data using the Socket communication technology, effectively ensuringthe timeliness and stability of communication.Experiments and runing show that the positioning and navigation subsystem stablelyoperates in the mainstream Android device, positioning quickly and accurately, fast andconvenient navigation operations to meet the actual demand for the entire exhibition center,providing accurate and reliable navigation services. And also provides a reference todeveloping similar indoor positioning and navigation system.The paper is organized as follows:Chapter1(Introduction) introduces the research background, purpose andsignificance of the subject, and the main work done in this article.Chapter2(related technical description) describes the related technologies used in theprocess of design and implementation, there are near-field communication (NFC), WiFipositioning technology, maps plans, and the algorithm of finding the path.Chapter3(overall design) introduces the needs analysis of the topic, moduledivision, the overall architecture, server architecture, database design and interface design.Among them, the overall architecture using C/S and B/S mode combining, the serverarchitecture using the MVC model.Chapter4(detailed design) on the basis of the overall design, using the graph, usecases, class diagrams and code implementation to describe the design process, including theinterface design, implementation of position, implementation of navigation. Among them, thenavigation module uses the Dijkstra algorithm, and improves the search efficiency bylimiting the scope of the search using a rectangular area.Chapter5(commissioning and running) describes the configuration and operation of structures and the development environment, by comparing the actual map with the runningresults, proving that the subsystem has achieved good results.Chapter6(Summary and Outlook) summarizes the main work of this paper, andindicates the next direction improved of indoor positioning and navigation subsystem of theexhibition center navigation service system based on the WiFi+NFC.