The Method Study Of Geomagnetic Indoor Localization On Smartphone

With the urban development becoming more and more mature,the building is becoming more and more big and underground,and how to define its position clearly is becoming the new demand of the modern city people.People begin to pay attention to location-based information service,especially in large and complex indoor environment.Some scholars have proposed Wifi positioning,Bluetooth positioning and geomagnetic positioning methods.In these methods,there is no need to pre lay the signal source in the indoor positioning of the geomagnetism,and the cost of hardware input is low.Secondly,the geomagnetic signal has good stability and high positioning accuracy.At present,apple smart phones,Android smart phones and other smart phones are open to the development of geomagnetic sensors interface,smart phone based magnetic positioning software can be used across platforms.In this paper,we propose a method to solve the indoor positioning problem based on the smart phone platform.The core of this algorithm is an improved reliability enhanced Kalman filtering algorithm.In many indoor positioning algorithm based on geomagnetic field,Kalman filtering algorithm is considered to be one of the most promising localization algorithm,is used to solve the problem that fingerprint is not high and the geomagnetic sensor error or noise,and improve the positioning accuracy.This experiment is based on the magnetometer,sensor and other sensor data of the smart phone.It is real-time and reliable,and the test data can be collected by smart phone without professional acquisition equipment.This paper uses Kalman filter algorithm to improve filter algorithm to get the geomagnetic data and PDR data are analyzed by Matlab software,using the magnetic field as the indoor positioning technology fingerprint shows its superior unique characteristics(such as no infrastructure,high precision,stability etc.).This paper bases on the smart phone which is widely used as a platform and has a wide user base.The various functions of the localization algorithm are based on smart phone sensors,and the cost is low and easy to spread without adding additional equipment.Experimental results show that the average positioning accuracy of this method is 1-2 meters.