A Low-Cost INS and UWB Fusion Pedestrian Tracking System

An inertial navigation system (INS) using kinematic sensors is able to provide accurate pedestrian tracking over a short distance. Information fusion of the INS with wireless technology has been commonly employed to develop more robust and accurate tracking systems over longer distances. An ultra-wideband (UWB)-based system offers further improvement and achieves positioning error in order of centimetres. Existing INS and UWB integrated systems require at least three anchors at known locations for positioning in the covered area. The deployment cost of such systems is high, since UWB devices are more expensive than other commonly used wireless nodes. The need to obtain the exact locations of all anchor nodes is also contributed to the additional cost in system deployment. In this paper, a low-cost INS and UWB integrated pedestrian tracking system is proposed using only one UWB anchor node at an unknown location, minimizing infrastructure cost and setup. The anchor location is estimated at the initial stage of tracking with the aid of an INS tracking algorithm. Afterward, the UWB ranging measurements are fused with INS data to provide robust and accurate tracking performance. The system is evaluated with pedestrian tracking experiments over long distances and achieves up to 85.75 % reduction in average positioning error when compared with an INS-only solution.