Exploiting the Orientation of Trilateration UHF RFID Tags in Robot Localization and Mapping

Abstract

This paper considers the problem of Simultaneous Localization and Mapping (SLAM) that requires the estimate of the position of passive UHF-RFID tags to make a reference map to be used in localizing the robot. The robot, a unicycle-like vehicle, is equipped with wheel encoders and an RFID reader that collects the phase of the signals backscattered by a set of tags placed on the ceiling of the environment in unknown position. The problem is solved by resorting to a particular kind of tag, referred to as TriLateration Tag (TLT), that consists of three closely spaced antennas. The proposed solution improves the performance obtained in previous research by estimating, in addition to the range and the bearing of the TLT with respect to the robot, also its orientation. This allows to obtain slightly better performances and to effectively solve the problem even if using a single TLT.