602 research outputs found
ReLoc: Hybrid RSSI- and phase-based relative UHF-RFID tag localization with COTS devices
Radio frequency identification (RFID) technology brings tremendous advancements in the Industrial Internet of Things (IIoT), especially for smart inventory management, as it provides a fast and low-cost way of counting or positioning items in the warehouse. In the last decade, many novel solutions, including absolute and relative positioning methods, have been proposed for this application. However, the available methods are quite sensitive to the minor changes in the deployment scenario, including the orientation of the tag and antenna, the materials contained inside the carton, tag distortion, and multipath propagation. To this end, we propose a hybrid relative passive RFID localization method (ReLoc) based on both the received signal strength indicator (RSSI) and measured phases, which orders the RFID tags horizontally and vertically. In this article, the phase-based variant maximum likelihood estimation is proposed for lateral positioning, and the RSSI profiles of two tilted antennas are compared with each other for level distinguishing. We implement the proposed positioning system ReLoc with commercial off-the-shelf RFID devices. The experiment in a warehouse shows that ReLoc is a powerful solution for practical item-level inventory management. The experimental results show that ReLoc achieves an average lateral and level ordering accuracy of 94.6% and 94.3%, respectively. Notably, when considering liquid or metal materials inside the carton or tag distortion, ReLoc still performs excellently with more than 93% ordering accuracy both horizontally and vertically, indicating the robustness of the proposed method
Experimental Assessment of Orientation Sensing and Constructive Interference in Passive RFID Systems
Recommended from our members
Performance Analysis of Passive UHF RFID Systems under Cascaded Fading Channels and Interference Effects
In this paper, the performance of monostatic and
bistatic passive ultrahigh-frequency radio-frequency identification
(UHF RFID) systems under the effects of cascaded fading
channels and interference is studied. The performance metric
used is tag detection probability defined as probability that the
instantaneous received power is higher than the receiver’s sensitivity.
A closed-form expression of the detection probability is
derived using cascaded forward and backscatter fading channels
and reader antennas orientation. Furthermore, the performance
of passive RFID systems under reader-to-tag interference caused
by both the desired RFID signal and multiple RFID interferers
is analyzed, and the effect of constructive and destructive
interferences is examined. In addition, the maximum reading
range in ideal, multipath fading and interfering environments is
presented. The obtained results are very useful for the design and
optimization of passive RFID systems from RF point of view.This work was made possible by NPRP grant NPRP4-726-2-272 from
the Qatar National Research Fund (a member of Qatar Foundation).This is the accepted manuscript. The final version is available from IEEE at http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=6942226
On the use of passive UHF RFID tags in the pharmaceutical supply chain: a novel enhanced tag versus high-performance commercial tags
Item-level RFID-based tracing systems are of growing interest both from industrial and scientific standpoints. In such a context, the choice of the most adequate RFID tag, in terms of shape, frequency, size and reading range, is crucial. The potential presence of items containing materials hostile to the electromagnetic propagation exacerbates the problem. In addition, the peculiarities of the different RFID-based checkpoints make the requirements for the tag even more stringent. In this work, the performance of several commercial UHF RFID tags in each step of the pharmaceutical supply chain has been evaluated, confirming the foreseen criticality. On such basis, a guideline for the electromagnetic design of new high-performance tags capable of overcoming such criticalities has been defined. Finally, driven by such guidelines, a new enhanced tag has been designed, realised and tested, demonstrating that high performance item-level tracing systems can actually be implemented also in critical operating conditions. Copyright © 2013 Inderscience Enterprises Ltd
Dense and long-term monitoring of Earth surface processes with passive RFID -- a review
Billions of Radio-Frequency Identification (RFID) passive tags are produced
yearly to identify goods remotely. New research and business applications are
continuously arising, including recently localization and sensing to monitor
earth surface processes. Indeed, passive tags can cost 10 to 100 times less
than wireless sensors networks and require little maintenance, facilitating
years-long monitoring with ten's to thousands of tags. This study reviews the
existing and potential applications of RFID in geosciences. The most mature
application today is the study of coarse sediment transport in rivers or
coastal environments, using tags placed into pebbles. More recently, tag
localization was used to monitor landslide displacement, with a centimetric
accuracy. Sensing tags were used to detect a displacement threshold on unstable
rocks, to monitor the soil moisture or temperature, and to monitor the snowpack
temperature and snow water equivalent. RFID sensors, available today, could
monitor other parameters, such as the vibration of structures, the tilt of
unstable boulders, the strain of a material, or the salinity of water. Key
challenges for using RFID monitoring more broadly in geosciences include the
use of ground and aerial vehicles to collect data or localize tags, the
increase in reading range and duration, the ability to use tags placed under
ground, snow, water or vegetation, and the optimization of economical and
environmental cost. As a pattern, passive RFID could fill a gap between
wireless sensor networks and manual measurements, to collect data efficiently
over large areas, during several years, at high spatial density and moderate
cost.Comment: Invited paper for Earth Science Reviews. 50 pages without references.
31 figures. 8 table
- …