Simultaneous Localization and Mapping Using the Phase of Passive UHF-RFID Signals

An indoor simultaneous localization and mapping (SLAM) problem for a mobile robot using the Radio Frequency IDentification (RFID) technology is considered. The system consists of a reader, installed on the robot, which measures the phase shift of the UHF-RFID signals coming from a set of passive tags deployed on the ceiling of the environment. The position of the tags is unknown and only an approximate knowledge of the ceiling height is available at the beginning. A Rao-Blackwellized Particle Filtering approach is proposed to fuse the RFID measurements with the robot odometry and to determine both the robot pose and the tag coordinates. Simulative and experimental results are reported to illustrate the effectiveness of the proposed approach: the precision obtained is in the order of a few cm