An indoor pedestrian positioning system based on inertial measurement unit and wireless local area network

Pedestrian dead reckoning (PDR) systems which based on inertial sensors to capture user's movement, and wireless positioning systems which adopt wireless local area network (WLAN) for indoor pedestrian localization have been widely studied in recent years. Inertial navigation system is self-contained and reliable in a short period of time with errors accumulated over time. Wireless positioning has bounded errors, whereas indoor signal fluctuation results in its inaccuracy. An indoor pedestrian positioning system which integrates inertial navigation and WLAN positioning is presented in this paper. A foot-mounted inertial measurement unit (IMU) and two extended Kalman Filters are employed to utilize information from zero velocity update (ZUPT) and wireless positioning in order to correct accumulated errors in inertial navigation system. Field experiments show that with the aid from WLAN indoor, the position accuracy from inertial navigation is improved from 6.3 m to 1.2 m in a range of 300 meters. The proposed system is simple and practical with relatively high performance.