| With the rapid development of the mobile internet, smart mobile terminal technology and mobile computing technology, Basic demands of indoor LBSs(location based service) are explosive improved, which makes indoor positioning technologies become hot spot in intelligent LBS domain. To solve the ’last kilometer’ and ’last meter’problems of navigation and location service, many technology giants and research institutions such as Google, Apple, Baidu and so on, undertaken a lot of researches in indoor positioning technology and promotion. Indoor positioning technology is gradually beginning to affect people’s lives in the form of indoor navigation guide, tour guide, shopping guide, and etc. Especially, the "XiHe" research program, as indoor supporting engineering of "BeiDou" navigation and positioning,aims for high precision indoor positioning within the scope of wide-area, which embodies the national will.However,been different from outdoor space,indoor space structure and indoor entity constitute are more complicated and easy varied, phenomenon such as the positioning signal obscured, multipath transmission and non line-of-sight transmission are common, leading to positioning errors of wide-area signal like FM/GSM/GPRS are larger. Indoor positioning could reach accuracy of 5 meters based on local signal of radio frequency technology like Bluetooth, WiFi and RFID. With the help of gravity sensor, acceleration sensor, geomagnetic sensors and other mixed position method,higher precision as 1 meter of the positioning could be achieved. But, the problems are that it will be easy to increase the power consumption of terminal system and reduce system continued service capacity significantly. The basic cause of the indoor positioning problem lies in the particularity of indoor environment applied multiple influence on indoor positioning, while existed obvious conflict between indoor positioning, LBS positioning higher demands of precision and efficiency, and the conflict is an unresolved contradiction body. From the perspective of indoor space analysis, theoretically, it can get a better positioning accuracy by establishing a more precise positioning signal transmission model. But in practice, there are still no breakthroughs.To meet the demand of high precision, low cost and low energy consumption of indoor pedestrian positioning, this paper took smart phone, Bluetooth(iBeacon), WiFi and other technologies which are cheap, low energy consumption and universal as the basis platform, took indoor space scene analysis as the means, took optimize the improvement of indoor positioning technology as the target. Above this, this paper tried to study and discuss the proper indoor positioning technology and optimization methods ,which are more adapt to real space environment limit, and are more precise and more stable.Followings are the main research contents and main results in this paper:1. Build a theoretical system of indoor space positioning constraints. (1) proposed a type division with point, line, and area constraint of indoor positioning. Compared to the current study of anchor node correction, the map correction and other positioning constraints mode, this paper was planning for the point, line, area type confinement.Boiled down the traditional location transfer method of space scene to further simplify the positioning and constraint process, for example, buffer method can be simplified as point type constraint or line type constraint. (2) Based on indoor space division,proposed indoor space divided method with entrence, passageway and container.So linkages between indoor positioning space and physical entities could be strengthen. (3)Build a kind of EPC_G graph to divide indoor space which is based on entrance,regarded as edge, channel and container, regarded as nodes. (4) Consistent data sources and spatial subdivision techniques with IndoorGML, through multi-tier architecture and associated data source method from IndoorGML, the entrence passageway container space division method will have practical applications.2. Constructed a space-scene analysis method for indoor space constraints. (1)Proposed the formal definition and conception of the entrance scene, passageway scene and container scene.based on the geometric characteristics of its space scene. Discusses the division and location constraints to achieve its breakdown characteristics. (2)Discussed the RSSI values and iBeacons in the smart phone, iBeacon signal conditions screening algorithm, space scene recognition algorithm, constrained parameter space entry and Scene Position quantization algorithm; (3) Designed the methods of classification deployment ,consolidation deployment method , scenes matching and sensors filtering.3. Proposed an indoor positioning technology optimization pattern considering indoor space-scene. (1) Discussed technical solutions to optimize the indoor positioning from the angle of optimization foundation and prerequisite, process optimization,algorithm optimization.(2) Discussed positioning processes as double RF signal propagation, RSSI mean data processing optimization,RSSI strongest beacon,scene recognition and so no. (3) Designed scene constraints common positioning methods including of prefab positioning space, first time positioning and correcting postioning.4. Specifically discussed the indoor positioning technologies for the entrance scene, the passageway scene and container scene optimization methods. (1)Built the VQueue model, for the vertical floor position and the horizontal positioning, and oriented to entrances scene positioning process. (2) Built trilateration positioning optimization method based on RSSI-Distance considering indoor space-scene , with processes as identifying of space-scence, optimal flitering of iBeacon, and correcting of results optimization . (3) Built fingerprinting positioning technology optimization methods considering indoor space-scene, with processes as flitering of real time RSSI and spatial fingerprint, matching of fingerprint fragments and so on.Experiments show that the model, algorithms and techniques are correct and validity of this paper. (1) According to the judgment of VQueue model, faceiing entrance scene into or leaving positioning is determined to achieve a 90% correct positioning, time delay within 2 seconds. (2) Based on the trilateral positioning technology considering indoor space-scene, in the narrow channel, for example, in 2 meters corridor, it achieved the accuracy of better than 1 meter horizontal positioning accurity and its stability is 100%. (3) Based on fingerprint positioning technology considering indoor space-scene, in a wide channel and container, achieved the point to be located and the position of the fingerprint grid consistency positioning results.At the same time, the positioning grid space is reduced by 30%, real-time fingerprint matching spaces reduced by 50%, achieved significantly improvement on the positioning efficiency.In the progress of this paper, facing closely to predestrian-oriented indoor positioning, under universal basic conditions ,sunch as smart phone mobile terminals,WiFi and iBeacon and other low-cost, for example, RF signal source, study is targeting more basic and representative:(1) Considering the construction and maintenance, the location source sensor is mainly the industry production of iBeacon seekey system sensor. (2) Using Huawei P7, Samsung S5, Coolpad Y75 and other common smart phone.(3) RF signal propagation model based on the classical model number, use the partition fitting transmission model.(4) RSSI value processing in real-time using the mean filtration.(5) Using trilateral centroid location algorithm as Location-based technology, KNN algorithm based on Euclidean distance, etc. So that the process and outcome of this paper is more comparable and universal, and also easier to be promoted and applied. |
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