Research And Realization Of The Patrol Indoor Positioning And Tracking System Based On WiFi Fingerprint And Inertial Navigation

With the rapid development of all kinds of wireless communication and network technology today,the demand of location-based services is also increasing among people.Global positioning system(GPS)can realize positioning and navigation in the global area.In the open outdoor environment,GPS can provide the high precision positioning information.However in the indoor environment,with the occlusion of the buildings,the received signal of satellite will be interfered and become extremely weak and we can not obtain the valid information.Especially in the arsenal with the complex indoor environment,it is unable to complete the indoor positioning by GPS.Thus,the positioning technique that can be applied in indoor environment has become the focus of research in the field of positioning.With the gradual development of WLAN-based WiFi positioning technique and sensor-based inertial navigation positioning technique,they are widely used in the positioning fields of indoor environment by virtue of their characteristics of low cost and strong adaptability.Meanwhile,with the development and emergence of radio frequency identification(RFID)technology,its properties of non-line sight,free touch,high-speed recognition are well known.In a large arsenal,the patrols are usually equipped with patrol car to complete the huge task.It is difficult to determine the specific location of the patrols,so some patrols will be off work without authorization.In order to solve this problem,this paper will design a patrol indoor positioning system.Then the observers can monitor the patrols to get their real-time positioninformation and follow the tracks of them to ensure that patrols can finish the task within work time.In this papar begin with introduction and comparison of different indoor positioning technology and mature positioning system on broad and domestic,analyzes their advantages and limitations.Secondly,for the special environment like arsenal,patrol indoor positioning and tracking system is put forward based on WiFi fingerprint and inertial navigation.The system uses C / S soft framework,which is made up of server end and client end.First,the server completes the acquisition of patrol location information.The core of the server is STM32F103 microcontroller,which connects WiFi,geomagnetic sensor,Hall sensor and RFID respectively collecting the WiFi fingerprint of patrol members,driving directions,traveled distance and elapsing RF tags.Then,the server will send all positioning information through Socket communication based on TCP / IP to the client end.Finally,the client end shall reduce fluctuations of fingerprint sequence by applying average smoothing method in the offline stage,and classify WiFi fingerprints by applying K-means clustering algorithm.In line-positioning stage,through the integration of the improved K-nearest neighbor fingerprint algorithm and inertial navigation positioning,the positioning is completed.Next,conduct real-time positioning towards the patrol on the system test platform and track the members' travel path.