Research And Implementation Of Wearable Seamless Navigation And Positioning System Based On Smartphone

With the development of smartphone and its sensors,pedestrian navigation and positioning technology based on smartphone becomes an important emerging branch in the field of navigation.Smartphone navigation system can provide location and heading information for pedestrians at anytime and anywhere,thus it has broad application prospects in civilian areas such as emergency rescue,traffic safety and so on.In this paper,the implementation of indoor and outdoor pedestrian seamless positioning method based on low-cost sensors is researched.Firstly the recent developments in the area of pedestrian navigation system are reviewed,and the key technology of smartphone and wearable equipment positioning are analyzed.Secondly,the overall design scheme of wearable seamless navigation system based on smartphone platform is proposed to improve the accuracy of GNSS.Navigation and positioning mode is divided into two types: indoor and outdoor,and the seamless navigation and positioning fusion strategy of the switching between indoor and outdoor is researched in this paper.To address the problem of low precision and easy divergence of smartphone sensors,the improved PDR algorithm is proposed,which can effectively solve the problem of navigation accuracy.In order to improve the usability and flexibility of positioning,auxiliary wearable devices is used to achieve high-precision indoor positioning.In order to improve the accuracy of pedestrian positioning and navigation in outdoor environment,this paper introduces the GNSS and magnetic sensor into the system.Multi sensor data is fused by extended Kalman filter to obtain the best positioning accuracy.The analysis results show that the use of GNSS and magnetic sensor assistant can effectively improve the accuracy of pedestrian navigation and positioning.The seamless positioning strategy integrates the navigation technology in different environments,which meets the requirement of seamless connection when pedestrian moves between different environments.Mobile navigation electronic map is the basis of pedestrian navigation.Indoor map integrates indoor and outdoor geographic information seamlessly.A doorplate recognition algorithm for obtaining the initial position and heading is proposed based on visual sensor inside smartphone.In addition,an indoor and outdoor environment recognition algorithm using fusion information of light sensor,magnetic sensor and satellite signal inside smartphone is proposed,according to the change of the sensor signal when indoor and outdoor environment is changing.This technology can provide accurate indoor and outdoor environment detection for smartphone applications.Finally,the seamless navigation and positioning software is designed in ECLIPSE environment.The Baidu map software package is used to carry on the secondary development to support the solution and display.The experiment verifies the feasibility of the smartphone seamless positioning system,which can real-time display the navigation solution.