A Fuzzy Logic Approach to Passive RFID for Mobile Robot Applications

Passive Radio Frequency Identification (RFID) is being increasingly used in mobile robotics applications, as it provides inexpensive and effective solutions to data association issues in basic navigation tasks. Nonetheless, problems related to sensitivity of the signal to interference and reflections, and missing tag range and bearing information are open. In this paper, we propose a novel approach to passive RFID, which tackles those issues using fuzzy reasoning. Specifically, first, we present a fuzzy antenna model. Then, based on this model, we describe two fuzzy logic methods for tag localization. One allows us to accurately localize passive tags in the environment and to generate what we call an RFID-augmented map; the other is suited for estimating the bearing of a tag relative to the robot. The general use of both methods is in object localization, map building, environment monitoring, and robot pose estimation. Results of experimental tests demonstrate that fuzzy logic is appropriate to operate under uncertainty in RFID systems, and allows for accurate tag localization.