UHF RFID System Research Articles

MRPSO-Loc: Multi-targets UHF RFID localization system based on MRPSO algorithm

Existing RFID localization techniques mainly focus on the location of a single target, which do not fully utilize the multi-targets identification merit of UHF RFID systems. In this paper, a multi-targets localization algorithm called merged re-shaken particle swarm optimization (MRPSO) is proposed. The ranging information and the angle information, which are obtained by using multi-frequency phase information with the help of frequency hopping technique, are merged together during the iteration process of MRPSO. In addition, based on the traditional PSO algorithm, a low weight particle filtering method was proposed, and a re-shaken scheme was introduced to improve localization accuracy. By allocating particles to each target, MRPSO can obtain each target location simultaneously after PSO process, which avoids time consuming. The experimental results show that MRPSO can achieve single-station multi-target localization with a median accuracy of 9.64 cm.

Design and implementation of a cryptographic algorithm based on the AES advanced encryption standard for UHF RFID systems

Design and implementation of a cryptographic algorithm based on the AES advanced encryption standard for UHF RFID systems

Moc-SAR: Motion Compensation for Synthetic Aperture-based Holographic Localization in UHF RFID System

Moc-SAR: Motion Compensation for Synthetic Aperture-based Holographic Localization in UHF RFID System

Evaluating the Activity of Pigs with Radio-Frequency Identification and Virtual Walking Distances.

Monitoring the activity of animals can help with assessing their health status. We monitored the walking activity of fattening pigs using a UHF-RFID system. Four hundred fattening pigs with UHF-RFID ear tags were recorded by RFID antennas at the troughs, playing devices and drinkers during the fattening period. A minimum walking distance, or virtual walking distance, was determined for each pig per day by calculating the distances between two consecutive reading areas. This automatically calculated value was used as an activity measure and not only showed differences between the pigs but also between different fattening stages. The longer the fattening periods lasted, the less walking activity was detected. The virtual walking distance ranged between 281 m on average in the first fattening stage and about 141 m in the last fattening stage in a restricted environment. The findings are similar to other studies considering walking distances of fattening pigs, but are far less labor-intensive and time-consuming than direct observations.

Multicarrier Communication for UHF RFID: Increased Reliability and Coverage for UHF RFID Systems

Multicarrier Communication for UHF RFID: Increased Reliability and Coverage for UHF RFID Systems

Non-invasive Frozen Meat Monitoring System Using UHF RFID Tag Antenna-Based Sensing and RSSI

The conditions of frozen meat products must be closely monitored in cold chain logistics (CCL) to maintain their quality and safety. Sensing and monitoring meat products are currently invasive, costly, and lacking tracing capabilities. Therefore, developing a wireless, passive, and cost-effective sensing system capable of tracking and monitoring remains challenging. This work investigates the UHF RFID system performing antenna-based sensing for monitoring frozen meat using the received signal strength indicator (RSSI) data. A commercial off-the-shelf (COTS) UHF RFID reader is programmed through a single-board computer to acquire the RSSI data throughout the RFID 902-926 MHz band. In the experiments, RSSI data from an RFID inlay tag affixed to a defrosted frozen meat sample is acquired for approximately 20 minutes. Then, the RSSI data is recorded periodically during the changes in the sample condition. The experimental results signify that the RSSI data have monotonic relationships with the temperature and hardness of the meat sample. The three-degree polynomial regression models are constructed to show the non-linear relationships between the RSSI and the frozen meat condition. During defrosting, the RSSI lowers as the meat temperature rises and the hardness reduces. Therefore, antenna-based sensing employing the RFID RSSI data can detect changes in frozen meat temperature and hardness, allowing conditional fluctuations in the CCL to be monitored. This work paves the way for low-cost IoT-based sensing systems for improving food safety in cold chain applications.

A Spectrum Injection-Based Approach for Malware Prevention in UHF RFID Systems

A Spectrum Injection-Based Approach for Malware Prevention in UHF RFID Systems

Remote Management and Tracking System for Commercial Refrigerators Using UHF RFID Technology

In this study, RFID based solution was developed for the commercial medical type refrigerators to identify products, expiration dates, and monitorize the entire life of products from the manufacturer to the end user. The medical products such as vaccines, drugs, blood and plasma products will be tracked, and product losses will be minimized with this solution. The results showed that UHF RFID system successfully identified the products in the commercial type refrigerator. Thanks to the RFID technology to be used in the designed project, the RFID tags on the product were automatically read for each product entering the refrigerator, and the products were monitored and managed via a web-based control panel.

Bite-o-Mat: A device to assess the individual manipulative behaviour of group housed pigs

• Validation of a new device to automatically assess manipulative behaviour in pigs. • Algorithms were developed and validated for the rearing and fattening period. • About 60 % (= sensitivity) of the rope manipulations were detected by an algorithm. • The algorithm reached a specificity and accuracy above 80% for the detection of rope manipulations. • During greater than 65 % of manipulations the manipulating pig was correctly identified. Tail biting is still an important problem in pig husbandry. In addition to addressing the underlying causes, the negative consequences of tail biting can be mitigated by detecting it early e.g. using behavioural changes and implementing intervention measures. Due to the labour intensity of behavioural observations, it would be highly advantageous to detect behavioural changes automatically. This study aimed at developing and validating an automatic device (“Bite-o-Mat”) to assess the individual manipulative behaviour of group-housed pigs. The Bite-o-Mat consisted of a single point load cell (SPLC) that recorded the force with which pigs manipulated a rope, and an UHF-RFID system to individually identify the manipulating pig. Data were recorded in a rearing (8 pigs) and a fattening pen (5 pigs) and validated using twelve hours of video recordings each, distributed across six days. Pigs were observed 596 (rearing) and 277 (fattening) times to manipulate the rope (=manipulation event) in the videos to which the automatically recorded data were compared. Using a linear mixed model, summarising data per manipulation event, it was possible to show that on average stronger forces are exerted on a rope during manipulation events than during times without manipulations and that these forces can be measured by a SPLC (manipulations vs. no manipulations, model estimates in kg; rearing: -0.01 vs. -0.004 (mean), fattening: -0.05 vs. -0.01 (mean)). Based on these results, an algorithm was developed to automatically detect manipulation events using the data of the SPLC. Validation of the algorithm using a second-by-second comparison to the video analysis, showed that it is suitable to detect manipulation events automatically in the rearing and fattening period (sensitivity: 0.60 (rearing and fattening); specificity: 0.87 (rearing), 0.93 (fattening); precision: 0.55 (rearing), 0.58 (fattening); accuracy: 0.81 (rearing), 0.88 (fattening)). In addition, we aimed to identify the manipulating pig with an UHF-RFID antenna. The performance parameters (sensitivity, specificity, accuracy, precision) of the UHF-RFID antenna confirmed that it is sufficiently suitable to detect the pigs within the reading range. Compared with the video recordings, 69% (rearing) and 82% (fattening) of pigs were correctly identified automatically to be the manipulating pigs by the UHF-RFID algorithm. These results indicate that the Bite-o-Mat is not only a promising device to automatically detect manipulative behaviour in group-housed pigs, but also to identify the manipulating animal.

Improved UHF-RFID Tag Design and Middleware Implementation for Effective Site Management and Access Control at Construction Site

Effective site management and access control are useful aspects to implement at the construction industry. In particular, monitoring personnel, construction materials, and equipment is considered predominant elements at these sites as they constitute more than half of the total project cost. Thus, to provide accurate and timely information of man/materials, UHF-RFID technology integrated with Middleware acts as a pioneering solution for real-time data monitoring. This work develops a new approach to implement the Automatic Identification and Data Capture (AIDC) solution through Middleware integrated with the UHF-RFID system. To design a UHF RFID tag, we propose a new platform tolerant Artificial Magnetic Surface (AMC) meta surface integrated tag for tracking man/material at the construction site. The novelties of the proposed tag lie in its improved radiation characteristics and stable high read range performance on different items. The designed tag was fabricated and tested experimentally in a real outdoor scenario by placing it on different items such as personnel and metal objects. At the same time, we developed UHF-RFID system integrated web application through Middleware to provide digital worksite visibility for access control and on/off-site management. Thus, the developed system will act as an automated tool to remotely fetch the information from different working zones at the construction site.

UHF RFID: Retail Store Performance

The development of UHF RFID technology has reached significant performance advancement in the last 20 years. Both tags and readers are now improved with better sensitivity levels providing a potential for achieving greater tag read ranges. However, the performances of the technology are also limited by complexity and electromagnetic (EM) properties of the environment in which the system operates. The aim of this contribution is to evaluate how well the state-of-the-art UHF RFID systems behave in an actual retail store environment rather than in a controlled anechoic setting. An extensive empirical study is performed and data for the performance analysis are collected from both a commercial reader and an USRP-based sniffer. It is shown that physical and MAC layer should be considered cooperatively in order to improve the overall system performance. Specifically, although the tag responsiveness depends on the products’ EM properties as well as the number of products and their relative position in the basket, still the appropriate reader mode of operation can ensure a reliable and stable reading process. For the item identification and localization in the smart IoT stores, the EM properties of retail products should be taken into account in the data classification.

Electromagnetic Characterization of UHF-RFID Fixed Reader in Healthcare Centers Related to the Personal and Labor Health

Hospitals and healthcare centers are experiencing a remarkable implementation of new systems based on wireless communications technologies. Many of these systems provide location services and identification of materials, instrumentation and even patients, which promotes the increase of the quality and the efficiency of healthcare. A tracking system based on short-range radio frequency, UHF-RFID is evaluated. This system helps with location of orthopedic prosthesis according to the criteria and requirements of a specific hospital environment. It is characterized the influence of UHF-RFID system in the electromagnetic environment by measuring the parameters and characteristics of the emission levels. The results of the assessment are represented through 2D contour maps and simulations have been performed by means of an in-house 3D-RL algorithm. The proposed graph aims to provide a methodology of studying the electromagnetic environments and the evaluation of the safety conditions of workers, patients, and people in general. E field exposure levels due to the RFID localization system were analyzed in order to verify regulations concerning the safety of patients and the general public in the labor and healthcare fields. Localized electromagnetic field exposure at levels which may cause electromagnetic hazards in the specific healthcare environment have been found and potentially excessive exposure to EMF emitted by UHF RFID devices may apply to patients or bystanders. In all cases, insufficient electromagnetic immunity of electronic devices (including AIMD and other medical devices) should be considered and the electromagnetic hazards may be limited also by relevant preventive measures, as also shown in this paper, together with the principles of an in-situ evaluation of electromagnetic hazards near the UHF-RFID devices.

An ISAR-SAR Based Method for Indoor Localization Using Passive UHF RFID System With Mobile Robotic Platform

A novel RFID inverse synthetic aperture radar (ISAR)-synthetic aperture radar (SAR) localization method is proposed and demonstrated which exploits reference tags with known locations to estimate the trajectory of a mobile platform and locate target tags with unknown locations. A system that integrates a mobile robot with an integrated RFID reader and antenna is used to obtain phase measurements of both reference and target tags when the robot is moving along its trajectory. The ISAR algorithm estimates the antenna trajectory and a novel ISAR-SAR loop then adjusts the estimated trajectory. The estimated trajectory is combined with phase measurements of the target tags to determine their location. The performance is compared to SAR using a LiDAR measured antenna trajectory. Similar localization accuracy (15 cm MAE) is achieved using LiDAR-SAR or ISAR-SAR method with a straight-line trajectory and higher accuracy (6 cm) is achieved using ISAR-SAR method than LiDAR-SAR method (8 cm) with an L-shape trajectory.

An Intelligent Shopping System based on UHF RFID

In the context of COVID-19, in order to solve the problems that customers need to spend more energy to find products in the supermarket, long checkout queue time, and cumbersome product management, optimize the shopping route of customers, accelerate the shopping process, and reduce the risk of infection; providers exceed Supplier’s sales of goods, and then timely and purposeful selection of goods, simplifying the supply chain process between supermarkets and suppliers. This article designs a multi-terminal interactive intelligent shopping system based on UHF RFID to construct The shopping cart terminal, mobile phone APP terminal, data management system terminal, and three-terminal interactive system with RFID technology as the core are developed. The design uses the UHF RFID system to identify the information in the electronic tags of the goods, and through the navigation function, helps customers locate the desired goods, and realizes the functions of identification, information display, navigation and positioning, and settlement.

An Efficient Identification Algorithm to Identify Mobile RFID Tags

Tag identification in a fast‐moving environment is an emerging challenge for future RFID systems. However, existing literatures on the tag reading protocol design primarily apply to stationary scenarios, which fail to cope with mobile environments with unreliable channel condition. In this paper, we first review various types of prior reading protocols and then discuss a new direction of mobile tag reading by proposing a novel partitioning strategy. This analysis and experimental results show its superiority in achieving reading performance for the UHF RFID system under a mobile environment.

Broadband and Fast Carrier Cancellation for Backscattered RFID Communications

Ultrahigh frequency radio frequency identification (UHF RFID) uses backscattered electromagnetic (EM) modulation techniques to communicate between readers and tags. The suppression of the carrier signal leaked from the transmission channel to the receiving channel is the key factor that determines the reader’s sensitivity. In this letter, a broadband, fast carrier cancellation technique is proposed. The reader system uses two transmission ports: one is for the transmission of the interrogating signal and carrier waves (CWs) and the other port can dynamically sample the leakage signal in the receiving channel and generate a cancellation signal with the same amplitude but opposite phase of the leakage. This technique is implemented using an AD9361 transceiver chip as RF front end and a field-programmable gate array (FPGA) board as the protocol and cancellation controller. Experiments demonstrate that a suppression of around 92 to 106 dB can be achieved within 0.5 ms in a UHF RFID system. The cancellation technique is also broadband; with a matched antenna, the experiment shows that cancellation can work effectively from 0.3 to 6 GHz.

Case Study on Recording Pigs’ Daily Activity Patterns with a UHF-RFID System

The main objective of this paper is the monitoring of daily activity patterns of fattening pigs at different locations in the housing environment using UHF-RFID. Four hundred fattening pigs were equipped with UHF-RFID ear tags and monitored during the fattening period for about four months. The RFID antennas were installed at the feeding troughs, playing devices and drinkers. A validation phase for each of these locations was carried out prior to the first data collection. The sensitivity (true positive rate) of the UHF-RFID system was about 80% at the feeding trough and the playing device and about 60% at the drinkers. The mean of the daily visiting time of all pigs at the trough was about 55 min. The mean visiting duration at the playing device was about 38 min and at the drinkers about 9 min. The visiting times of the pigs showed a high intra- and inter-variability. It was observed that the average visit duration at the feeding trough decreases over the course of a fattening period but increases at the playing device. A documentation of visiting times of animals is possible utilizing RFID systems, allowing a higher data density than video or direct observations.

A Method to Improve Identification Performance of UHF RFID Systems

A Method to Improve Identification Performance of UHF RFID Systems

Vehicular Localization With Using China Electronic License Plate System

In the past five years, electronic license plate (ELP) systems have been widely deployed in most China big cities, which provide a novel solution for vehicular localization. Since vehicular position information plays a crucial role in intelligent transportation systems (ITS), the ELP based vehicular localization method is studied to overcome the shortcoming of camera based method in this paper. The ELP system, a customized UHF RFID system, uses RFID tag as a electronic license plate and RFID reader as ELP reader. Thus, the vehicular localization problem is transformed as a ELP localization problem. After analyzing, a ranging based solution is proposed to solve the vehicular localization problem. A multi-frequency based phase difference of arrival (PDOA) ranging algorithm is utilized to calculate the distances between the ELP and antennas. Then, the localization problem is modeled as an optimization problem and the reason why traditional algorithm can not solve this problem is discussed. After that, a novel local search based algorithm is proposed to solve the localization problem. Various experiments are designed and performed to verify the proposed method. Experimental results show that the proposed method achieves a centimeter level ranging and localization accuracy and the proposed localization algorithm converges quickly.

Miniaturization of Circularly Polarized Patch Antenna for RFID Reader Applications

This paper presents a Circularly Polarized Microstrip Patch Antenna (CPMPA) miniaturization with parasitic elements, suitable for UHF RFID systems. The antenna consists of a half E-shaped patch with cuts. A truncated corner patch can generate an additional Circular Polarization (CP) radiation mode and further enhance the axial ratio. Two symmetric cross shaped slots along the horizontal axis of the CPMPA have been embedded, and its dimension optimization has been based on parametric analysis. Thanks to this slotted structure and reduced surface area, good CP quality has been obtained with a 25% overall size reduction. The proposed antenna is lightweight, low profile, simple, and easily produced. The structure’s simulation is made using CST Studio Suite 2014 to compute return loss (S11), gain, and the axial ratio of the antenna while the overall miniaturized antenna’s volume is 77mm×58mm×1.6mm operating at 915MHz.