Navigation for Occupational Safety in Harsh Industrial Environments

The importance of location based services (LBS) has largely increased for consumer applications and becoming more and more relevant in industrial applications. For example location dependent information can support occupational safety staff to ensure the safety at work in emergency scenarios. In outdoor environments localization can be obtained easily by using a global navigation satellite system (GNSS). For harsh indoor environments, however, where most industrial applications require localization, an accurate localization remains a challenge in general. In this paper we present a hybrid localization system enabling navigation in challenging environments. The hybrid system fuses received signal strength (RSS) based wireless sensor network (WSN) ranging and a foot mounted inertial measurement unit (IMU). The key contribution of this paper is a hybrid localization concept and experimental results using a deployed system in an industrial environment. We characterize the wireless sensor network signal propagation and evaluate the magnetic field for heading stabilization in such environments. The accuracy analysis shows a typical error of 2 meters. In comparison to a pure inertial navigation system (INS) approach, we demonstrate the enhancements introduced by the combination of an inertial navigation system and a wireless sensor network received signal strength based localization.