Research Of WiFi-PDR Joint Indoor Positioning Algorithm Based On Smartphone

With the rapid development of mobile Internet and wireless communication technology,location based service(LBS)has become more and more important in the field of airport,underground parking,large shopping center and other places,which has great application market demand.So far,an indoor positioning method which is leading all-weather has not been found.In this paper,considering the applications and the applications of the crowd for indoor positioning technology,the indoor positioning technology will combine with smartphones,researching based on the smartphone' WiFi-PDR combination of indoor positioning technology can better show indoor positioning technology application prospect,The main work and innovation of this paper are as follows:(1)WiFi fingerprint location based on normalized RSS and constraint WKNN.WiFi location fingerprint algorithm is used for positioning,and the obtained coordinate value is provided to the PDR algorithm as the initial position value.WiFi location fingerprint localization algorithm uses the normalized RSS value weights offline-online signal acquisition error correction method to reduce the signal random error,so as to make the RSS value close to ideal.Meanwhile,the WKNN matching location algorithm based on 4-domain system is used to prevent the error,which is caused by the reference point far from the point to be measured,in order to improve the initial positioning accuracy.(2)Pedestrian movement pattern assisted PDR positioning.The indoor special location node is sensed by the pedestrian movement pattern,and the PDR algorithm is modified with the indoor map information at the special location node.For example,in the interior corner,it is possible to use the topological structure information of the special location node in the room to match it to the indoor special location node correctly,and to eliminate the cumulative error of the PDR algorithm by giving the initial coordinates of the PDR algorithm again by the indoor map information.(3)WiFi-PDR combination indoor positioning based on smartphone.Based on the initial position coordinates provided by the WiFi location fingerprint algorithm,the PDR algorithm is used to positioning,and the cumulative error of the PDR algorithm is modified by the pedestrian movement pattern combined with the topological structure information(indoor map information)of the special location node in the room.Finally,the experiment shows that the WiFi-PDR combination indoor positioning technology based on smart phone has further improved the indoor positioning accuracy and is effective.