ITNA20090028A1 - INTELLIGENT CONTAINER EQUIPPED WITH RFID SYSTEM ABLE TO TRACK, IDENTIFY AND RECOGNIZE OBJECTS. - Google Patents

Description

DESCRIPTION OF THE INVENTION HAVING THE TITLE "SMART CONTAINER EQUIPPED WITH RFID SYSTEM FOR TRACKING, IDENTIFYING TAGGED OBJECTS"

DESCRIPTION

Field of application

Containers equipped with RFID reader with wide detection range, antennas arranged in such a way as to guarantee the best condition of electromagnetic coverage such as to make it possible to detect UHF type tags integrated on even small objects whatever their spatial position, of closing and opening, which can be unlocked after univocal identification of the operator, carried out through various user recognition systems.

Controllers equipped with middleware implemented according to the EPC GLOBAL standard, able to act as an intermediate layer between the containers and the information management application, generalizing the libraries with which the individual readers are equipped and allowing periodic and reliable detection of objects; database, for the persistence of information; interface to provide the operator with updated information on the current state of the objects.

The system has various applications, including but not limited to:

identification of document files, texts or works of art with tags regardless of archiving, each time the object is moved from its container,

continuous inventory of drugs, registration of any take-away operations of the responsible operator and verification of the correct drug-patient combination,

tracking of the goods handled between different shelves, between different warehouses of the same logistics operator or in a supply chain system,

control of aviation maintenance tools in order to eliminate so-called "damage from foreign objects",

tracking of the visitor path and evaluation - eg. - the total number of guests at the single stand and the average time of stay.

State of the art

RFID technology (hereinafter referred to as "RADIO FREQUENCY IDENTIFICATION"), essentially created to supplant the bar code, finds many applications in the most disparate civil and industrial fields. Compared to barcodes and other identification technologies, radiofrequency technology offers numerous advantages: reading does not require direct contact or "optical sight", and therefore there is no need for a particular orientation towards the reader or scanner. .

Several tags (RFID tags) can be read at the same time; they can work in dirty, contaminated environments and also withstand very difficult conditions (environmental agents, thermal, chemical, mechanical stresses). They are therefore more durable and contain more data than the barcode and can be rewritten and updated with new information. Furthermore, the barcode only identifies the type of product, but not uniquely the single object. The tag, on the other hand, can contain a unique and unique serial number to identify every single product manufactured in the world.

The most widespread applications of RFID technology currently range from the traceability of goods within the supply chain in industrial and commercial activities, to the identification of people, animals and things; such applications pose technical problems and are burdensome also due to the solutions available up to now in the state of the art.

There are, in fact, still some problems not yet well resolved regarding the use of electromagnetic waves. In RFID systems with passive tags - as on the other hand also happens for radars - the transmitter sends an electromagnetic wave and the receiver detects the scattering (improperly also called "reflection") generated by an object on which the wave affects. When the receiver is co-located with the transmitter, the phenomenon is called backscattering (in the following, for the sake of simplicity, backscattering will also be called reflection, albeit in the relative inaccuracy of the term). Scattering is defined as "the process by which the energy of a traveling wave is dispersed with respect to the direction of propagation, due to the interaction with the non-homogeneities of the medium". This occurs when an electromagnetic wave hits an object and induces oscillating charges and currents in the object and on its surface and, consequently, a new electromagnetic field is generated. RFID tags modulate backscattering by varying the impedance of their antenna, and this allows communication with the RFID reader, also called reader or scanner.

Another problem is that in the range of a reader there may be several tags to identify. When the tags are irradiated by the electromagnetic field of the reader they can respond simultaneously generating collisions. It is therefore necessary to equip the reader <-> tag communication system with an anti-collision mechanism. The tags contain a unique identification code called SID (Simulaneous I Dentifier) which allows the simultaneous identification of multiple tags within the field of the same reader. The communication process between reader and tag can be summarized in two moments: the reader sends a REQ (request) query message indicating the type of operation to be performed to the tag; the tag responds with an ATQ (Answer to Request) message containing the SI D, any additional data, the correctness of the dialogue, the presence of errors, the outcome and result of the operations performed. There are two models of management of the anti-collision mechanism:

Deterministic (ISO 14443 part 3 type A - "Binary search tree");

Stochastic (ISO 14443 part 3 type B - "Slotted Aloha") whose operating principle is based on time division multiple access (TDMA).

The problems related to anti-collision protocols are of fundamental importance in situations where there are many tags in the interrogation area. In fact, as the number of tags increases, collisions increase and the time in which all tags are correctly detected increases. However, this growth is not linear but exponential: as the number of tags increases, errors significantly increase and a longer reading cycle must be set.

The placement of the tag without respecting the polarization of the field generated by the reader causes significant reductions in the operating distance; a tag oriented orthogonally with respect to the field generated by the reader may not be read. Devices with passive EM coupling must take into account two main characteristics of the antennas (both of the reader and of the tag):

Radiation diagram

Polarization of the EM field

The radiation diagram is the three-dimensional representation of the antenna gain, the latter measured (in logarithmic units-dB) by comparison between the antenna in question and an isotropic reference antenna (i.e. that radiates equally in all directions). It is usually preferred to consider the horizontal and vertical sections of the (three-dimensional) radiation diagram. The intensity of the field generated by an antenna is a function of the radiation pattern of the antenna itself. For optimal power transfer between reader and tag, the maximum intensity vectors of the radiation patterns of the two antennas must be aligned.

Passive tags use amplitude modulation techniques and receive power from the reader field. Energy transfer occurs in a "far field" regime. In this region of space, in the electromagnetic theory, the electric and magnetic components of the field radiated by a conductor (antenna) propagate in free space as a combined wave (electromagnetic wave). At very high frequencies (UHF) we always operate in a "far field" or at distances at which inductive coupling is no longer the prevailing effect, so that the antennas (typically dipole) of the tags can capture the electromagnetic field as in traditional radio communication systems. When the electromagnetic wave emitted by the reader affects the antenna of the tag, part of the energy is absorbed to supply power to the tag (through an ordinary alternating to direct voltage rectifier circuit); a small part, on the other hand, is reflected back towards the reader as backscattering.

Passive tags do not have their own sources of energy to transmit. For the communication between tag and reader, therefore, the modulation of the backscattering effect is exploited. The modulation of the backscattering is obtained through the variation of the antenna impedance of the tag during the transmission of the signal by the reader. The task of the reader is to capture the consequent variations in the reflected signal.

The use of the far-field backscattering modulation technique introduces problems different from those that occur in lower frequency systems. One of the biggest problems is due to the fact that the field emitted by the reader is not only reflected by the antenna of the tag but also by all the surrounding objects with dimensions comparable to the wavelength used. These reflex fields (multipath or multipath) overlap the main field emitted by the reader and can cause it to be softened or even canceled. Furthermore, problems could arise deriving from the response signal (modulated) on the same frequency as the interrogation signal of the reader.

The electromagnetic field can be represented with two electric field vectors E and magnetic H orthogonal to each other and with respect to the x axis of propagation of the signal. If the direction of the two vectors remains unchanged and only the intensity and direction vary in a sinusoidal way, the signal is said to be linearly polarized. If the vectors of the electric field E and magnetic H rotate around the x axis (direction of propagation of the signal), the signal is called circular polarization. A parallel direction of the two electric field vectors (and necessarily also the two magnetic field) of the tag and reader antennas causes maximum energy transfer. In other words, if the antennas are linearly polarized, the relative dipoles must be parallel. If at least one of the antennas is circularly polarized, this latter condition is not necessary, and it is sufficient that the axes of maximum signal propagation coincide.

These technical problems - as illustrated in the publications and in the patent applications already encountered and reported below - have raised several important issues that have been addressed and resolved for the realization of the container described above.

Prior publications and rights

[1] L Battezzati - J. Hygounet, RFI D Automatic identification by radio frequency, Ulrico Hoepli Editore, 2003

[2] http://RFIdjournal.com

[3] Design of an "intelligent" Physical Level for Highly Reconfigurable Mobile Networks A. Massa, (1) C. Regazzoni, (2) G. Riccio (3)

http://www.eledia.ing.unitn.it/PRIN2005/MECSA/PaperMECSA.pdf

[4] J. Lee and A. Lai, "FDTD analysis of indoor radio propagation," Proc. IEEE-AP Symp., Atlanta, 1998, pp. 1664-1667.

[5] M.J Gans ,. N. Amitay, Y.S. Yeh, Xu Hao, T.C. Damen, R.A. Valenzuela, T. Sizer, R. Storz, D. Taylor, W.M. MacDonald, Tran Cuong, and A. Adamiecki, "Outdoor BLAST measurement System at 2.44 GHz: calibration and results," IEEE J. Select. Areas

Commun., You. 30, pp. 570-583, 2002.

[6] Thesis: "APPLICATIONS OF RFI D TECHNOLOGY" Davide Brognoli Academic Year 2004-2005 UNIVERSITY CATHOLIC OF THE SACRED HEART, BRESCIA OFFICE Faculty of Mathematical, Physical and Natural Sciences

[7] Technical and regulatory aspects on the use of RFID in Italy - Antonio Vellucci - Ministry of Communications - Directorate General for Planning and Management of the Radioelectric Spectrum - May 2006.

[8] RFID and NFC Measurements with the Real-Time Spectrum Analyzer - Application Note - 2005 - www.tektronix.com/RFId.

[9] Security in Near Field Communication (NFC), Strengths and Weaknesses -Ernst Flaselsteiner and Klemens BreitfuR - Philips Semiconductors - Workshop on RFID Security, Graz - July 2006.

[10] Radio Frequency Identification Technology (RFID) - IEE 2005.

[11] RFID Technical Tutorial - Dale R. Thompson - Department of Computer Science and Computer Engineering - University of Arkansas.

[12] A Radio-Oriented Introduction to Radio Frequency Identification - Daniel M. Dobkin, Titus Wandinger - High Frequency Electronics - June 2005.

[13] DS-UWB Physical Layer Submission to 802.15 Task Group 3a - several authors - July 2004.

[14] Upstreaming RFID - Beyond Tags and Readers - T S Rangarajan, Anand Vijaykumar, Suraj Subramaniam S, - TATA Consultancy Services - 2005.

[15] Receptivity - A TAG Performance Metric - Impinj - December 2005.

[16] Near Field Communication (NFC): Exchange and distribution of contactless information and content - U. Biader Ceipidor, F. Greco, C.M. Medal, A. Moroni -Wireless - October 2006 (http://www.wirelessmanagement.it/200609/default.asp).

[17] Binetti, Giulio, Boggia, Gennaro, Camarda, Pietro and Grieco, Luigi Alfredo (2007), "A Hashing-based Anti-Coll ision Algorithm for RFID Tag Identification", Proc. Of ISWCSO7.

[18] EM MICROELECTRONIC - MARIN SA, 2002. "EM4022: Multi Frequency Contactless Identification Device".

[19] Harald Vogt. "Efficient Object Identification with Passive RFID Tags". Department Federal Institute of Technology (ETH).

[20] John Capetanakis. "Tree Algorithms for Packet Broadcast Channels". IEEE trans, on information theory, vol.it-25, no.5, pp. 505-515, September 1979.

[21] Ching Law, Kayi Lee, Kai-Yeung Siu. "Efficient Memoryless Protocol for Tag Identification", MIT Auto-ID Center, 2002.

[22] Marcel Jacomet, Adrian Ehrsam, Urs Gehrig. "Contactless Identification Device with Anticollision Algorithm". University of Applied Sciences Berne Biel School of Engineering and Architeture.

[23] Augustus Janssen, Marc de Jong. "Analysis of Contention Tree Algorithm". IEEE trans, on information theory, vol. 46, no. 6, pp. 2163-2172. September 2000.

[24] M. Kaplan, E. Gulko, "Analytic properties of Multiple Access Trees". IEEE trans, on information theory, vol.it-31, no.2, pp. 255-263. March 1985.

[25] G. Fayolle, P. Flajolet, M. Hofri and P. Jacquet, "Analysis of a Stack Algorithm for Random Multi-Access Communication". IEEE trans. on information theory, vol.it-31, no.2, pp. 244-254, March 1985.

[26] Marta Cavagnaro "Dosimetry of electromagnetic fields" Dept. of Electronics Engineering - "La Sapienza" University of Rome ICEmB - Interuniversity Center Interaction between Electromagnetic Fields and Biosystems

DESCRIPTION OF THE FOUND

The invention consists of an integrated machine or computer / program or application system (hardware / software) that allows the objects stored in a closed container or in a a space defined by the volumes of the irradiation solids of the antennas placed in it.

The technical solution provides that this must be achieved through a detection system that is:

independent of the user of the objects;

independent of the make and model of the reader;

usable wherever the container is placed;

capable of collecting and managing information relating to the objects contained in the tags;

modular and scalable.

The system consists of a container and a controller.

The container

The container is a common deposit, in which a set of antennas and an RFID reader are integrated. Inside the container the antennas are positioned in such a way as to allow the best condition of electromagnetic coverage such as to make it possible to detect tags whatever their spatial position.

The container can be configured as a closed container, i.e. defined as a space determined by the superposition of the volumes of the irradiation solids of all the antennas connected to the reader, so it can be, by way of example only, a room, an apartment or an office, a building, a city, depending on how and where the antennas are distributed.

The system is able to identify, recognize, trace, control the objects present even in multiple containers, as well as identify the person responsible for moving them.

The functionality of the physical, periodic and reliable detection of objects is entrusted to the readers and antennas integrated inside the containers. The antennas represent the interface between the tag and the reader: they are dipole or patch type (Fig.7); in the latter case the electromagnetic field propagates with spherical polarization.

The detection of each object is made possible by pre-marking each of these with an RFID tag. The frequency band used by the system in question is UHF, which allows for tags that are small enough to be integrated on different objects and a sufficient range for their detection. The UHF tags (Fig. 6) represent the markers for the identification of the single objects by the reading subsystem of the container. Each tag must be physically attached to an object. For each type of object, the most appropriate type of tag must be chosen in relation to its shape and size and the type of application. The shape of the tag must not be distorted as any deformation affects its performance.

Having identified the mechanism through which the container detects the objects with tags, the functionality of the system is achieved through the communication of the container with a controller that allows to keep in a database the information relating to the objects that the container has detected or the operations registered on them.

Each container - in general - interfaces through an Ethernet or wi-fi network with a server (Fig. 9). In the case of mobile containers, both a wi-fi network connectivity must be provided, through the provision of an access point (Fig. 8), and a power supply (e.g. battery, solar panels, etc.), integral with the container, to supply the energy necessary for the operation of the on-board system.

The controller

The controller is - in turn - an integrated hardware / software system consisting of a computer that manages the services (server), configured with middleware, databases, applications and interfaces, i.e. computer programs designed to receive, process, store and present the data from containers and information about users, containers themselves and objects.

The management of the information received from the tags through the readers is subject to various processes depending on the purpose for which the system is intended. To make it possible to correctly manage the information flows along the phases of the tag control process, a middleware has been developed that can act as an "intelligent interface" between the container and the information management system (Fig. 1).

The found middleware is a new implementation of the GLOBAL EPC standard model. This standard, in addition to considering the integration of individual RFID technologies, has provided the system designer with a higher level abstraction of the devices than that provided by the individual applications that control the readers (Fig. 2).

The methodology used is based on this model independent of the specific implementation platform. Fig. 4 shows the UML diagram that describes the various software modules that make up the entire application developed.

The database management system is able to maintain the persistence of data, in particular relating to:

users and operators,

the different containers,

the objects present in the containers.

This means that the system provides all the functions for inserting, modifying, deleting, viewing and reporting the information relating to each user, container, object.

During the system configuration phase, the users must be defined, with their access data. The profile must be established based on the degree of accessibility to be guaranteed to the system.

For each container, the central system maintains a table in a database with the current list of the objects it contains. Each container is identified by a unique logical name, an IP address, a logical communication port and a subnet mask.

If all the containers communicate with the controller (and not with each other, in a star network), the latter must be able to guarantee the exchange of information necessary for the various devices to ensure the operation of the system. Alternatively, an application distributed on different controllers (each integrated in a container) can be developed: in this case all the devices will communicate with each other in a mesh network.

The controller has a registry of all objects. The system provides an administration interface for entering and editing information relating to each object.

When the containers are activated, a population operation of the relative associated tables is carried out automatically, through the detection of the tags present in the single container and the communication of the relative data to the controller. After that, the status information relating to its presence or absence inside the containers is periodically updated for each object in the database.

When an object leaves the container's control, it detects that the object is no longer present and informs the controller. Once a check point has been set, an object will be considered "out of control" in that instant, when the system does not detect its presence in any container. In the event that an object withdrawn, instead of being placed in the container of origin, is deposited in a different container, the latter detects this event and communicates it to the controller, which automatically updates the tables associated with the two containers.

After login (user identification by entering a pair of unique and secret credentials), an operator must logically associate with a container: in this way the operator takes control of the container and, consequently, also of the objects it contains. This association can be made through a workstation, a PDA, or possibly a touchable interface, portable or integral with the container itself, through which the system also makes available to the operator all the information - according to his profile - updated on the status of the individual objects in the registry.

When the operator performs the logout operation, or simply disassociation from the container, in the event that some objects - previously present in the system - are out of control, he receives a warning, or a warning or attention message, even if this is not binding for logout purposes.

The login can be done through automatic user recognition systems (fingerprint readers or other biometric sensors, RFID readers more typically HF, cameras, etc.). Even the operations of association and disassociation can be automated, through eg. relay locks.

The subject responsible for opening is registered by the controller together with the possible subtraction / insertion operation of an object.

Ultimately, the container allows the physical detection of the objects to be carried out, while the controller makes this operation periodic and reliable.

Claims (1)

CLAIMS of the industrial invention entitled "INTELLLIGENT CONTAINER EQUIPPED WITH RFID SYSTEM FOR TRACKING, IDENTIFYING TAGGED OBJECTS" The following is claimed: 1. integrated machine / application system consisting of one or more containers (closed containers or spaces determined by the overlapping of the volumes of the irradiation solids of all the antennas connected to the radio frequency reader) equipped with a radio frequency reader and antennas (and possibly access point and rechargeable battery), and by a controller configured with middleware, database, applications and interfaces capable of identifying, recognizing, tracking, controlling, automatically, the RFID markers (tags) placed on objects and communicating their presence o the absence of operators connected to it via a workstation, palmtop or other instrument; 2. the antennas referred to in claim 1 guarantee the generation of an electromagnetic field that propagates inside the container, being arranged in such a way as to guarantee the best condition of electromagnetic coverage such as to make it possible to detect the tags whatever their spatial position. ; 3. the container referred to in claim 1 can be equipped with a closing and opening device, which can be unlocked after unambiguous identification of the operator, carried out through different user recognition systems. The person responsible for the opening is registered by the controller together with the possible subtraction / insertion of an object; 4. the container according to claim 1 uses an RFID reader with a wide detection range which allows to use UHF type tags integrated on even small objects; 5. the controller referred to in claim 1 is equipped with a middleware implemented according to the EPC GLOBAL standard, capable of acting as an intermediate layer between the containers for RFID detection and the information management application; 6. the middleware - referred to in the previous claim - represents a generalization of the libraries that the individual readers are equipped with and therefore, through this middleware, the application is capable of communicating with all types of readers and allows periodic and reliable detection of objects; 7. the database referred to in the preceding claims maintains the persistence of the information and the application allows you to configure the descriptive master data of the objects with tags, the containers that store them and the users who operate, as well as define the responsibility of individual operators if an object is "out of control" and the system, when switched on, automatically populates the associated tables of the containers; 8. a workstation, a PDA or a touchable interface, portable or attached to the containers, allow the system to provide the operator with updated information on the current status of the objects; 9. the preceding claims allow - by way of example - the identification of document files, texts or works of art equipped with tags regardless of storage, each time the object is moved from its container, which can be configured for the management of simple office cabinets up to entire art galleries or libraries; 10. if the container referred to in the preceding claims is configured as a cabinet containing drugs, the system referred to in the preceding claims allows for each drug to have a continuous inventory, to record any take-away operations of the responsible operator and to verify the correct drug-patient matching; in the presence of warehouse shelves, the system as per the preceding claims can be configured to manage the tracking of the goods moved between the different shelves, between different warehouses of the same logistic operator or in a supply chain system; the system referred to in the claims can also be applied to the control of aeronautical maintenance tools in order to eliminate the so-called "damage from foreign objects", typically due to the forgetting of a tool on board in a critical area during assembly operations; An example of an intangible container can be the exhibition area of an organization in the trade fair sector: the system referred to in the preceding claims makes it possible to trace the path of visitors and to evaluate - among other things - the total number of guests at the individual stand and the average residence time.