Robust RFID Based 6-DoF Localization for Unmanned Aerial Vehicles

Although Unmanned Aerial Vehicles (UAV) are usually deploy outdoors, there is increasing interest in applying UAVs for indoor applications. It is a highly attractive and challenging task to precisely localize a UAV in an indoor environment where Global Positioning System (GPS) service is absent. In this paper, we present RFUAV, a Radio-frequency Identification (RFID) enhanced UAV system that provides a precise 6 degrees of freedom (6-DoF) pose for UAVs. With RFUAV, three or more ultra high frequency (UHF) RFID tags are attached to the UAV and are interrogated by a Commercial Off-The-Shelf (COTS) RFID reader with multiple antennas. Based on phase measurements of the RFID tag responses, the RFID tracker of RFUAV, a Bayesian filter-based algorithm, was employed to track the position of the tags in a global coordinate system. The pose estimator of RFUAV computes the 6-DoF pose of the UAV from tag positions. We tested the performance of RFUAV in a representative, structure-rich, indoor environment, where 0.04 m position error and 2.5 degrees orientation error were achieved.