| With the rapid development and rapid popularization of mobile internet technology,the Location Based Service(LBS)has been paid more and more attention.Research has shown that 80% to 90% of human life is in the indoor environment,so,indoor location is more and more important to people.In recent years,a variety of indoor positioning technology is emerging,but so far there is no unified global indoor positioning system.With the development of smart phone sensor system,the inertial sensors carried by smart phones can sense more information and many researchers have begun to study indoor positioning system based on smart phone inertial sensors.However,it is necessary to know the initial position in advance when depending on the inertial sensor for indoor positioning.Indoor geomagnetism has a high degree of stability and local differences that can be used as a positioning fingerprint to identify the indoor location.However,the simple use of geomagnetic data as location information usually can not be used directly,because it provides fewer positioning features.Therefore,it is of great application value and significance to integrate the geomagnetism information and the inertial sensor into the indoor location research.This paper focuses on the geomagnetism and inertial sensor fusion indoor location.the main contents of this paper are as follows:(1)Analysis of indoor geomagnetic information.The geomagnetic characteristics are studied and analyzed by measurement and mathematical calculation.In this paper,the stability of indoor geomagnetism with time,the characteristics of indoor geomagnetism under different terminals,and the characteristics of indoor geomagnetism at different heights and different directions are studied and analyzed.(2)Research on pedestrian mobile sensing based on inertial sensor.This paper focuses on the acquisition of pedestrian motion information through inertial sensors,including pace detection,step length estimation and motion direction estimation.An adaptive step detection algorithm based on four-threshold dynamic is proposed when detecting step.The step length estimation method based on the Queue idea and the fusion of acceleration step length model and the frequency step length model is proposed on the basis of the acceleration step length model and the frequency step length model.Finally,kalman filter technology is used to integrate the electronic compass and gyroscope to estimate the direction of the compass and gyroscope,meanwhile,the the direction also be corrected according to pedestrian walking habit.(3)Research on indoor positioning fusion algorithm based on improved particle filter.In this paper,an improved particle filter algorithm is proposed to fuse geomagnetism information and pedestrian mobile sensing information.On the basis of positioning fusion algorithm in the basic particle filter,the algorithm is improved from the particle initialization and resampling stages respectively in order to solve the problem of existing algorithm.At the same time,the design of particle filter,the state transition model and the state observation model are further optimized according to the actual situation of this paper.Finally,the experiment and analysis of the positioning system proposed in this paper are conducted.The experimental results show that the positioning system proposed in this paper has excellent positioning performance.(4)The software design and implementation of indoor positioning system.In this paper,the indoor positioning system software is realized through the Android system and the Java platform.The software mainly includes the client positioning App software and the positioning server software.The main function module design and UI interface diagram of the software are given.At the same time,communication framework between positioning App and positioning server the corresponding design for is design. |
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