A passive UHF-RFID system for the localization of an indoor autonomous vehicle

A Global Localization System combining odometry data with RFID (Radio Frequency IDentification) readings is proposed. RFID tags are placed on the ceiling of the environment and can be detected by a mobile robot unit traveling below them. The detection of the tags is the only information used in the proposed approach (no distance or bearing to the tag is considered available), but differently from similar localization setups reported in the literature, only a small number (about one each $m^{2}$ or less) of tags is used. This is possible using a suitable tag's antenna in Ultra High Frequency (UHF) band, expressly designed to obtain regular and stable RFID detection regions, which allows to consider an efficient Kalman filtering approach to fuse RFID readings with the vehicle odometry data. A satisfactory performance is achieved, with an average position error of about 0.1 m. The hardware/software localization setup described in this paper is cheap and easy to use, and may provide a satisfactory approach in several industrial and domestic scenarios.