Using multiple barometers to detect the floor location of smart phones with built-in barometric sensors for indoor positioning.

Hao Xia,Xiaogang Wang,Yuanfei Chang,Yanyou Qiao,Jun Jian

doi:10.3390/s150407857

Hao Xia, Xiaogang Wang + Show 3 more

Open Access

https://doi.org/10.3390/s150407857

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Abstract

Following the popularity of smart phones and the development of mobile Internet, the demands for accurate indoor positioning have grown rapidly in recent years. Previous indoor positioning methods focused on plane locations on a floor and did not provide accurate floor positioning. In this paper, we propose a method that uses multiple barometers as references for the floor positioning of smart phones with built-in barometric sensors. Some related studies used barometric formula to investigate the altitude of mobile devices and compared the altitude with the height of the floors in a building to obtain the floor number. These studies assume that the accurate height of each floor is known, which is not always the case. They also did not consider the difference in the barometric-pressure pattern at different floors, which may lead to errors in the altitude computation. Our method does not require knowledge of the accurate heights of buildings and stories. It is robust and less sensitive to factors such as temperature and humidity and considers the difference in the barometric-pressure change trends at different floors. We performed a series of experiments to validate the effectiveness of this method. The results are encouraging.

Highlights

Following the popularity of smart phones and the development of mobile Internet, the demands for accurate indoor positioning have rapidly grown recently
We believe that the major outlier sources in the floor positioning included the following factors: Type 1: Outliers caused by the smart phone platforms
We proposed a method (MBFP) of using multiple reference barometers for floor positioning in buildings

Summary

Introduction

Following the popularity of smart phones and the development of mobile Internet, the demands for accurate indoor positioning have rapidly grown recently. In addition to traditional map and navigation applications, location information becomes necessary for some applications such as social networking and e-commerce. Because we spend most of our time working and living indoors, a high-precision indoor positioning system (IPS) is important in many applications. Global Positioning System (GPS) has been used in various fields, but it cannot be used indoors [1]. Satellite signals cannot be used because they are highly attenuated by the walls of buildings. GPS signals that could be received propagate via a very complex propagation channel, i.e., not through a line-of-sight path; the propagation time cannot be directly transformed into distance

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