WPI precision personnel locator system: Inertial navigation supplementation

This paper describes the latest developments in the Worcester Polytechnic Institute (WPI) Precision Personnel Location (PPL) system. An RF-based system with inertial sensor supplementation is being developed for tracking of first responders and other personnel in indoor environments. The system assumes no existing infrastructure, no pre-characterization of the area of operation and is designed for spectral compliance and rapid deployment. The RF 3D location system has previously demonstrated sub-meter positioning accuracy of a transmitter even in difficult indoor environments with high multi-path with all receivers outside the building. However, accuracy can be severely degraded at particular locations within a building such as when a large and nearby metal panel blocks the direct path from the mobile transmitter to several receiving antennas. This paper describes the performance of our existing RF location systempsilas raw position estimate performance and how these raw position estimates may be filtered with motion constraints via the Kalman filter for improved accuracy. The paper goes on to investigate the use of inertial sensors to supplement the information from our RF position estimates, and how this information is fused together to provide improved overall system performance.