Research And Implementation Of Indoor Positioning Technology Using Smartphones

With the rapid development of mobile Internet, more and more people draw attention to the demand for location-based services, especially in large, complex, and varied indoor scenes, such as museums, guild hall, supermarkets, etc., often need to know the location of indoor and related services. Currently, the world famous university, as well as Apple, Google, Microsoft, Baidu and other technology giants, both regard indoor positioning technology as their research direction. These universities and technology giants focus on indoor positioning technology, enough to see the value of indoor positioning technology research value and potential commercial value. Smartphone has rich sensors resources and gradually increased processing capacity. With the popularity of smartphone, more and more researchers take it as indoor positioning carrier. However, due to the complexity of the indoor environment, there is no mature smartphone indoor positioning technology. Therefore, smartphones indoor positioning technology research has practical significance and broad application prospects.The main goal of this paper is to study and implement an indoor positioning system using smartphones. For the study of indoor positioning technology, the research work of this paper are the following aspects:1) This paper studies and analyzes the principles of pedestrian dead reckoning, and explains in detail the method steps of its implementation. Then this paper explains the three core issues to be addressed(the step size, the step detection, the direction of step). In the process of step detection, we propose a feasible step detection algorithm based on the accelerometer.2) This paper studies and implements the WIFI fingerprint indoor positioning technology, such as the nearest neighbor, naive Bayes etc.; due to WIFI signal is susceptible to environmental interference, the collected data need for filtering before gathering fingerprint and positioning. Through various algorithms positioning experiments, the paper compares the respective positioning accuracy and stability.3) This paper explores the pedestrian dead reckoning and WIFI fingerprint positioning their advantages and disadvantages, on the basis of the pedestrian dead reckoning positioning and WIFI fingerprints positioning, we propose an algorithm combines the advantages of both. The algorithm can correct the accumulated error of pedestrian dead reckoning, and can solve the problem of WIFI fingerprint positioning results imprecise and instability. Finally, the paper implement the indoor positioning system in Android platform, and the system contains the WIFI fingerprint positioning, pedestrian dead reckoning positioning and a combination of both.