Research Of Indoor-Outdoor Navigation Scheme Based On Multi-Mode Wireless Localization Technology

With the popularity of smart phones and the development of mobile Internet, the ability to navigate persons and devices in both indoor environments and outdoor environment has become increasingly demanding. For maturity of outdoor positioning, the key point of navigation is concentrated in the areas such as indoor positioning and the out-indoor scene changing. Although the availability of indoor positioning, driven by technologies like Wi-Fi, RFID, and Blue-tooth, has increased, Most of the current research into indoor localization has surrounded the problem of positioning accuracy.Accurate indoor geo-location is an important and novel emerging technology for commercial, public-safety, and military applications. However, indoor localization is very challenging due to the complex signal propagation that is caused by obstacles such as walls, clapboard, ceiling and so on. The electromagnetic wave may suffer reflection, refraction, diffraction and may result in the phenomenon of dense multipath arrivals and non line-of-sight propagation both of which will severely degrade the localization accuracy.Based on the above problems, the paper adopts PDR (Pedestrian Dead Reckoning) that use the terminal equipped with sensors as the principal algorithm of the fusion algorithm. The PDR mainly use the algorithms such as AHRS (An attitude and heading reference system), FSM (Finite-state machine), PCA (Principal Component Analysis), DTW (Dynamic Time Warping) and so on to process the data which collected by the sensors and extract the step numbers, step length and step direction, in order to calculate the pedestrian’s motion vector. In order to eliminate the deviation of sensors, that is accumulated by the time, the paper introduce the indoor land-mark which use the indoor features such as elevator, stairs and so on to mark the area’s coordinate as the assist of the PDR. When people go through the marked area, the terminal can get the coordinate directly to avoid the persistent deviation of PDR.We design a system for collecting sensor data and Wi-Fi signal based on Android platform. Through the processing of sensor data by the module written by Java language, The sixth chapter evaluate the effect the fusion algorithm of PDR and Land-mark.