Planar Position and Orientation Estimation Using a 5.8 GHz RFID System

Precise object position and orientation estimation using RF tags is an emerging application of RFID technology. In this work, we present a novel wireless two-dimensional position and orientation estimation and tracking technique that illustrates the concept of sensor fusion - using multiple, disparate sensor measurements to synthesize a single, superior estimation of position and orientation. The technique is implemented using 5.8 GHz RFID system that consists of three RFID readers and a customized motion capture tag equipped with 9-axis inertial and compass sensors. The microwave reader extracts 9-axis inertial and compass data: 3-axis accelerometry, 3-axis gyrometry, and 3-axis magnetometry from the backscattered packet. The HIMR algorithm then fuses inertial, compass data and the RF signature of the backscattered signal to produce a motion-capture grade estimate of position and orientation. A positional estimation accuracy of 1-2 cm was achieved in the narrowband experiments conducted using 5.8 GHz RFID system operating on multiple frequencies.