Pedestrian Dead Reckoning for Person Localization in a Wireless Sensor Network

Localization in areas where no global navigation satellite systems (GNSS) are available is still a challenging task. For pedestrian navigation this is especially interesting because this problem is faced more often than in other scenarios like car navigation. Wireless sensor networks (WSN) are one approach to indoor localization and allow an easy setup in ad-hoc scenarios. However, for networks with a low density of nodes or uncovered areas an additional localization method is needed. Pedestrian dead reckoning (PDR) is an ideal complementary system to supplement the localization with short time accuracy. This paper concentrates on an approach to PDR with low processing power for the use in WSN with a hip-mounted inertial measurement unit (IMU). The purpose of the system is to provide a localization and tracking solution if temporarily none or only few anchor nodes are within range. Steps are detected, the step direction is determined in coordinates of the IMU and the length of each step is estimated. We present an experimental evaluation of the system under varying environmental conditions and show that the concept is promising for the intended applications.