Target Localization by Mobile Handheld UHF RFID Reader and IMU

In this paper we design and construct a mobile handheld human operated device used to guide the user towards the desired RFID-tagged target, and at the same time provide estimations of the distance and the angle from the user to the target. The main components of the device are a UHF RFID reader operating with one antenna and an Inertial Measurement Unit (IMU), used to measure rotation angles. During the movement of the operator, phase of arrival and rotation angle data are collected by the RFID reader and the IMU respectively. A particle filter algorithm leverages the collected data to estimate the distance and angle of the operator, with respect to his/her current pose. As more iterations are completed, the fusion of multiple measurements improves the estimation performance. Experimental results show a mean angle estimation error of ~6°, and distance estimation error less than
$0.5m$
when the user approaches the target after few iterations. Recorded computational time is small-enough to enable real time tracking-applications.