RFID Smart Shelves

Nella presente tesi verrà trattato il tema della localizzazione in ambienti indoor mediante la tecnologia RFID (Radio Frequency IDentification): i primi sistemi RFID furono caratterizzati da semplici funzioni di identificazione a distanza di oggetti, persone o animali, mediante comunicazioni a radio frequenza tra le etichette elettroniche, o Tag, ad essi applicate ed un Reader. In tempi recenti sono entrati in via di sviluppo sistemi che utilizzano questa tecnologia non solamente per rilevare la presenza di un oggetto all’interno di un certo volume, ma anche per localizzare tale oggetto mediante stima delle coordinate del Tag ad esso applicato. Questo lavoro è rivolto alle cosiddette “Smart Shelves”, ovvero la realizzazione di scaffali per libri e vestiario, cassetti per medicinali, credenze o ripiani di frigorifero etc. che siano in grado di localizzare i Tag applicati agli oggetti al loro interno mediante comunicazione con antenne Reader; in particolare ci soffermeremo dettagliatamente sulla progettazione di un cassetto intelligente, ad esempio per medicinali, con lo scopo di introdurre delle linee guida di progetto da poter utilizzare nella localizzazione di Tag in questo particolare scenario. Sarà adottata la tecnologia RFID alle frequenze UHF (860MHz), unitamente all’impiego di Tag passivi e si analizzeranno quegli algoritmi che, partendo dalla disponibilità dell’informazione RSSI (Received Signal Strength Indication), permettano la localizzazione di Tag su una superficie bidimensionale

Vehicle recognition system using RFID technology for parking management system

© Published under licence by IOP Publishing Ltd. Technology is growing each day by leaps and bounds. The change in technology has done wonders to increase productivity in everyday life. However, drivers searching for parking contributed to traffic congestion especially in urban and suburban cities, while consuming their time and energy. Besides, traffic congestion in parking area is always an issue which contribute to traffic on the main road. The current approach to overcome this includes the implementation of parking ticket system, especially in busy area. The hour rate for busy area is elevated to promote liquidation of vehicles. However, this system requires patrol warden to manually inspect each vehicle for the parking ticket. The feasibility of the system decreases when the parking area is larger. RFID parking management system aims to bring automation into parking system. The use of passive UHF RFID which can read multiple tags from long distance can replace patrol warden and thus increase the effectiveness of the Vehicle Parking Management System (VPMS). Furthermore, the power consumption of RFID system is analyzed. A new method has been introduced to reduce the power consumption of RFID system which operates 24/7. Experimental results demonstrate the effectiveness of the proposed method in reducing the power consumption of the RFID system

Twins:Device-free Object Tracking using Passive Tags

Without requiring objects to carry any transceiver, device-free based object tracking provides a promising solution for many localization and tracking systems to monitor non-cooperative objects such as intruders. However, existing device-free solutions mainly use sensors and active RFID tags, which are much more expensive compared to passive tags. In this paper, we propose a novel motion detection and tracking method using passive RFID tags, named Twins. The method leverages a newly observed phenomenon called critical state caused by interference among passive tags. We contribute to both theory and practice of such phenomenon by presenting a new interference model that perfectly explains this phenomenon and using extensive experiments to validate it. We design a practical Twins based intrusion detection scheme and implement a real prototype with commercial off-the-shelf reader and tags. The results show that Twins is effective in detecting the moving object, with low location error of 0.75m in average

RFID-based smart shelving storage systems

In recent years, RFID systems that are widely applied for the identification of objects and people in radio frequency, are also going to be applied used for localization purposes. In indoor applications (apartments, shopping malls, airports), conventional solutions can use a number of signal parameters: instant of arrival ( Time of Arrival , Time Difference of Arrival, TOA, TDOA), angle information (Angle of Arrival, AOA), phase information (Phase Difference of Arrival , PDOA ) or the amplitude of the received signal (Received Signal Strength Indicator, RSSI). There are also some scenarios with small dimensions where the location can be extremely useful. For example, in a hospital, a better service could be offered through RFID technology, as it can add more control to prevent human errors. Indeed, RFID technology can be useful for correct patient drug supply, dose recording, accurate dispensing, anti-counterfeiting as well as replenishment ordering; besides, it simplifies the information transfer between doctors and nurses (e.g. allergic reactions or drug treatment). In retail industry, real-time inventory based on RFID allows to monitor actual customer demand for products, to prevent an out-of-stock situation by timely replenishing orders, to increase sales through additional services (e.g. fitting rooms with smart mirrors providing suggestions to the customer). In food and restaurant industry, RFID technology allows for a better food control, as for example avoiding expired products sale. In this framework, RFID-based smart shelves, smart freezers, and proximity point readers have been developed in libraries, hospitals and retail industries. In Chapter I, a brief introduction on RFID systems will be presented, in particular describing the main components involved and the principle of operation. It will be described what is proposed in literature about RFID smart shelf and localization algorithms, with particular attention to the methods exploiting the RSSI information. In Chapter II, an exhaustive experimental study by using off-the-shelf reader, antennas and tags, will be presented with reference to a wooden drawer filled with drug boxes. The LDA algorithm (supervised classifier) will be compared with the K-Means clustering algorithm (unsupervised classifier), to validate the proposed method. The procedure to get several RSSI average samples during the drawer sliding actions is described, and classification performance is investigated. First of all, an RSSI analysis is described with reference to a static configuration of the drawer (not sliding). Then, two classification algorithms are compared by considering a different number of drawer sub-regions. In the second part, the algorithm exploiting the drawer sliding is described and system performance is illustrated to verify the classification capability in a two-region drawer. In Chapter III, a localization technique for smart bookshelves based on UHF-RFID systems is presented. Two off-the-shelf reader antennas attached to the bookshelf columns, one in front of the other, are used as an alternative to large-area thin planar antennas integrated onto the shelf top. Two scenarios were considered: the first one with a shelf that is D = 97 cm long, and the second one with D = 150 cm. Exploiting RSSI data acquired by the two antennas, a clustering algorithm is implemented to classify tagged books within one of the regions the shelf has been subdivided into. Preliminary results of the system performance analysis have been compared with simulations to demonstrate that is possible to create an interference region in different sectors on the shelf, through a proper phase shift between the feed currents of the two antennas. The system requires a power divider, a switch, variable phase shifters and finally a fixed or variable power attenuator based on the size of the shelf. In Chapter IV the algorithm implemented will be described and then the performance results (in terms of normalized confusion matrix) will be presented and discussed. Finally, a preliminary analysis has been presented considering different tags, even if it is still under developing

Business case - Operation Honey Badger

This business case compares Radio Frequency Identification (RFID) and Laser Localization Technology for the improvement of the inventory accuracy at Synlait Milk Ltd (SML). This work is the result of "Operation Honey Badger", a research project on the feasibility of the implementation of RFID tags for inventory localization and tracking. The project was conducted by a student of the Master in EngineeringManagement program at the University of Canterbury as part of their academic requirement

Algorithms and Methods for Received Signal Strength Based Wireless Localization

In the era of wireless communications, the demand for localization and localization-based services has been continuously growing, as increasingly smarter wireless devices have emerged to the market. Besides the already available satellite-based localization systems, such as the GPS and GLONASS, also other localization approaches are needed to complement the existing solutions. Finding different types of low-cost localization methods, especially for indoors, has become one of the most important research topics in recent years.One of the most used approaches in localization is based on Received Signal Strength (RSS) information. Specific fingerprints about RSS are collected and stored and positioning can be done through pattern or feature matching algorithms or through statistical inference. A great and immediate advantage of the RSS-based localization is its ability to exploit the already existing infrastructure of different communications networks without the need to install additional system hardware. Furthermore, due to the evident connection between the RSS level and the quality of a communications signal, the RSS is usually inherently included in the network measurements. This favors the availability of the RSS measurements in the current and future wireless communications systems.In this thesis, we study the suitability of RSS for localization in various communications systems including cellular networks, wireless local area networks, personal area networks, such as WiFi, Bluetooth and Radio Frequency Identification (RFID) tags. Based on substantial real-life measurement campaigns, we study different characteristics of RSS measurements and propose several Path Loss (PL) models to capture the essential behavior of the RSS levels in 2D outdoor and 3D indoor environments. By using the PL models, we show that it is possible to attain similar performance to fingerprinting with a database size of only 1-2% of the database size needed in fingerprinting. In addition, we study the effect of different error sources, such as database calibration errors, on the localization accuracy. Moreover, we propose a novel method for studying how coverage gaps in the fingerprint database affect the localization performance. Here, by using various interpolation and extrapolation methods, we improve the localization accuracy with imperfect fingerprint databases, such as those including substantial cover-age gaps due to inaccessible parts of the buildings

Novel development of distributed manufacturing monitoring systems to support high cost and complexity manufacturing

In the current manufacturing environment, characterized by diverse change sources (e.g. economical, technological, political, social) and integrated supply chains, success demands close cooperation and coordination between stakeholders and agility. Tools and systems based on software agents, intelligent products and virtual enterprises have been developed to achieve such demands but either because of: (i) focus on a single application; (ii) focus on a single product; (iii) separation between the product and its information; or (iv) focus on a single system characteristic (e.g. hardware, software, architecture, requirements) their use has been limited to trial or academic scenarios. In this thesis a reusable distributed manufacturing monitoring system for harsh environments, capable of addressing traceability and controllability requirements within stakeholders and across high cost and complexity supply chains is presented. [Continues.