Environment Perception Based Seamless Indoor and Outdoor Positioning System of Smartphone

With the rise of location services applications, the need for navigation and positioning extends from isolated environments to a seamless, full domain. Aiming at the problem of low positioning accuracy in the transition area between indoor and outdoor, and it is difficult to achieve smooth switching, this article proposes an indoor and outdoor seamless positioning system for smartphones based on environment perception. Firstly, based on the hidden Markov model (HMM), we use smartphone observation data to select optimal features to construct an environmental perception model. Secondly, by increasing the magnetic field strength as an observation feature, the time delay for switching between different environments is shortened. Finally, based on the environmental perception results, a seamless indoor and outdoor positioning system is constructed. In the transition area between indoor and outdoor, to ensure the reliability of the positioning system, a Global Navigation Satellite System/ Inertial Navigation System/ Bluetooth Low Energy (GNSS/INS/BLE) integrated positioning model is proposed. In the outdoor and outdoor transition areas, we refine the stochastic model, which significantly improves the accuracy. To comprehensively evaluate the system performance, experiments are carried out in a complex environment. The experimental results show that the proposed perception model can accurately identify the changes of the environment, and the accuracy of judgment reaches more than 95%. It can support the seamless positioning system to select appropriate positioning models in different environments to achieve accurate and continuous positioning. The maximum positioning error does not exceed 0.5m.