EP2660788A1

EP2660788A1 - Anti-theft asset protection system and method by means of electromagnetic confinement techniques

Info

Publication number: EP2660788A1
Application number: EP12382164.7A
Authority: EP
Inventors: Pedro Díaz Aranda; Vicente Quilez Sánchez; José Manuel Mateos De La Cruz
Original assignee: Plettac Electronics Sistemas SA
Current assignee: Plettac Electronics Sistemas SA
Priority date: 2012-05-04
Filing date: 2012-05-04
Publication date: 2013-11-06
Also published as: WO2013164508A1

Abstract

Anti-theft asset protection system and method based on electromagnetic confinement techniques that comprise at least one wireless radiant element that generates an electromagnetic confinement space that is adapted to the particular geometry of each one of the possible scenarios without having to incorporate physical barriers or walkthroughs. If the wireless protection device attached to the asset to be protected gets out from the confinement space, it will not receive the surveillance code emitted by the radiant elements, and as a result, it will trigger a local sound alarm and a digital alarm managed, through a communication unit, by an external security platform.

Description

OBJECT OF THE INVENTION

The present invention relates, in the first place, to an anti-theft asset protection system based on electromagnetic confinement techniques for the assets to be protected. Secondly, the present invention relates to an anti-theft asset protection method also based on electromagnetic confinement techniques for the asset to be protected. The fields of application of the method and system object of the present invention are, in principle, any scenario in which protection of assets "subject to manipulation", such as in commercial enclosures, libraries, offices, hospitals, stores, etc., regardless of their dimensions and geometries and applied both outdoors and indoors, is of interest.

BACKGROUND OF THE INVENTION

The theft of objects from shops, usually known as "unknown loss", supposes an important problem with great economic relevance. This is aggravated due to the fact that this is a sector whose final trading margins are very limited.
At the same time, shop customers expect a greater degree of freedom when examining and trying out a particular article to see whether it is satisfactory before purchase, and therefore, they require having greater freedom to move with the article inside the sales department without being disturbed. In some shops, especially valuable objects are placed inside cabinets or are subject to severe mobility restrictions, pinned by electric cables, metal strips and chains, which supposes important restrictions in the customers' handling of the articles.
The consequence of the foregoing is the need to find technical asset protection solutions that satisfy these two needs simultaneously: a decrease in unknown losses and an increase in the customer's freedom when trying out the article freely within the sales area.
Unlike other current existing systems which base their functionality in the creation of physical barriers and the installation of antennae placed at strategic crossing points (access doors or hallways),which detect the crossing of passive tags attached to the articles to be protected, the proposed system and method propose the development of an asset protection architecture based on electromagnetic confinement techniques that allow detecting, without the need to establish any kind of physical barrier, any protected object intended to be taken out of the previously defined confinement area.
Document US2010277322A1 describes an asset theft detection system and method using an electromagnetic field generator, fixing at least one safety tag on the asset to be protected within the generated field. The geographical area radioelectrically covered by the field generator is local and placed in strategic locations. The electromagnetic field generator emits periodic pulses at a particular frequency, which are received by the tags. If the tags do not receive the pulses, they would trigger an alarm that they integrate, warning about the possible theft.
Document US20110121973 A1 , considered to be the closest to the state of the art of the present application, describes an asset protection system that generate an electromagnetic confinement area within which certain assets to be protected are located. The confinement area is generated by means of radiant elements and the assets are protected by means of their coupling to a tag that is configured to receive a signal emitted periodically from the radiant elements. If the tag does not detect the signal originating from the radiant elements, it would emit a local sound alarm and a radiofrequency alarm signal to certain elements, which, in turn, are connected to remote sound alarms, which would also be triggered.
However, none of the documents belonging to the state of the art of the present application has solved the problem of the electromagnetic shielding that takes place when the tags are introduced in metal bags or wrappers while preventing at the same time communications attenuation problems between the system's elements due to the objects and persons (static or in movement) located within the confinement area at the same time. The selection of a communication frequency between the devices falling within the low-frequency band LF/VLF prevents the problems associated to the attenuation due to the existence of static or moving objects and persons within the confinement area, but would not prevent the electromagnetic shielding. The selection of a frequency for the communication between the devices within the high-frequency UHF band, together with the use of UHF receptors of a great sensibility and a great dynamic range, would prevent the electromagnetic shielding, since the tag, even inside a metal bag, would still be able to communicate with the rest of the system's elements, but would have the problem of a high signal attenuation due to the existence of objects and persons within the confinement area.
In addition, the state of the art has not provided either the existence of a central element, to which the radiant elements are subordinated, allowing their wireless and remote configuration. This central element would also act as a link with an external security platform that would allow centralizing and supervising the appearance of alarms in the system externally and remotely.
The anti-theft asset protection system and method, based on the electromagnetic confinement of the assets to be protected object of the present application intends to provide a novel solution to this problem, by combining protection and freedom of manipulation in the handling of the articles on display.

DESCRIPTION OF THE INVENTION

A first object of the present invention is an anti-theft asset protection system by means of electromagnetic techniques, comprising at least one asset to be protected. This system comprises at least the following elements:

at least one radiant wireless element comprising: a UHF transceiver to send and receive communications to and from a communication unit, a VLF/LF emitter to send a radiofrequency signal to at least one wireless asset protection device, while the radiated power of the radiofrequency signal delimits an electromagnetic confinement space. The confinement area created is adapted to the particular geometry of each one of the possible scenarios without having to incorporate physical barriers or walkthroughs. The asset under protection will be located within the generated confinement space;
at least one wireless asset protection device fixed to the asset to be protected through anchoring means. Said protection device also comprises a sound alarm generator, a microprocessor, a motion detector, a VLF/LF receiver to receive the radiofrequency signal originating from at least one radiant element, a UHF transceiver to communicate the protection device to an electromagnetic confinement decoupler and to send alarms and alerts from the protection device to the communication unit;
a communication unit, comprising a UHF transceiver to receive communications originating from at least one protection device and to send and receive configuration parameters with at least one radiant element and with an electromagnetic confinement decoupler. In addition, it also comprises connection means with an external management and security platform through which alarms and alerts generated in the asset protection system are sent and the configuration commands of the asset protection system are received; and,
an electromagnetic confinement decoupler comprising a UHF transceiver to communicate with the communication unit and a VLF/LF transceiver to send commands to the protection device. The programming and decoupling of the protection devices are carried out by means of the UHF transceiver and the VLF/LF transceiver of the decoupler.

The number of radiant elements used for the creation of a single confinement space will depend on the volume of the space intended to be confined and the radiated power of the VLF/LF transceivers of the radiant elements. On the other hand, the number of protection devices will depend on the amount of assets intended to be protected, since each asset should have at least one protection device fixed therein.
In a particular embodiment of the invention, the radiant elements comprise at least one modular power driver circuit, managing the transmission power of the VLF/LF emitter, and a synchronism channel used to send and receive a synchronism frame between the radiant elements. Modular power driver circuits allow providing distinct and adjustable transmission powers for each individual radiant element. The combination of the coverage areas generated by each radiant element determines the adjustment of the global coverage area of the confinement structure to the desired profile and dimensions of each sale department.
In another embodiment of the invention, the communication unit comprises remote management means of the modular power driver circuit of each radiant element independently.
In another embodiment of the invention, the VLF/LF receiver of the protection devices comprises three antennae, each of which is oriented towards one of the spatial axes. This allows discriminating whether the protection device is located within the radio coverage area generated by the radiant elements or not, decreasing the uncertainty related to the spatial orientation of the device.
In another embodiment of the invention, the electromagnetic confinement decoupler at least comprises one control module, governed by a microcontroller, a user identification connector, a memory storing at least one list of authorized users, a USB connector and a power supply. The purpose of this element is to decouple the article protection devices by releasing them, once the shopping department vendor validates the purchase made by the customer. It also has a second function, which consists in programming the protection devices' individual parameters the first time they leave the factory or when they are intended to be used for the first time in a new or different department. It uses the VLF/LF channel to transmit the decoupling or programming codes to the protection devices, and uses the UHF channel to transmit the information related to the protection devices when it interacts with to the communication unit. The decoupler's operation with respect to the protection devices for the use of the VLF/LF channel is essentially local (the protection devices are a short distance away from the decoupler).
In another embodiment of the invention, an initial radiant element comprises means of control and management to synchronize the remaining radiant elements. The synchronization is carried out by sending the synchronism frame from the first radiant element towards the remaining radiant elements through the UHF synchronism channel periodically. In order to attain the foregoing, all of the VLF/LF transmitters of the radiant elements must transmit at the same time, so that the radiated signals are added positively. The clocks of the different transmitters have slight differences with one another, and these differences increase with time. If the transmitters were not synchronized, there would be a time when the signals radiated would not be added positively but negatively, and the coverage area would have dead zones, in which a protected element would not receive the surveillance signal and would trigger the alarm signal, even without leaving the protected commercial environment. Therefore, one of the radiant elements transmits a synchronization signal to the others so that the differences between the clocks of the different radiant element do not accumulate. This technical feature is relevant in certain scenarios in which the introduction of new cabling may represent an important problem in economic terms and ease of installation.
On the other hand, the wide range and diversity of articles to be protected requires the design of mechanical anchoring means so that the protection devices, which will look alike regardless of the article to be protected, may be attached to the very different articles to be protected in an appropriate manner.
In another embodiment of the invention, the anchoring means are selected between:

adhesives to be fixed on the asset to be protected and a contact activating the protection device when pressed;
at least one cable, as a loop, fixed by one of its extremities to the protection device and comprising fastening means to the device by its opposite extremity, remaining fixed to the asset to be protected by means of the introduction of the cable through an orifice of the asset and activating the protection device by fixing the fastening means to the device, closing the loop;
at least one spike to be introduced inside an orifice of the asset, fixed by means of a closing cap inserted in the spike, closing the contact by introducing the spike activating the protection device;
a hoop to fix the assets to cylindrical elements with a contact which, when pressed, activates the protection device;
dovetailing fixing means ending in a screw activating the protection device when reaching a stop; and
a combination thereof.

In another embodiment of the invention, the radiant elements communicate with one another by means of a RS485 interface to send and receive the synchronism frames.
In another embodiment of the invention, the protection system comprises a UHF jamming detector, which allows checking the existence of jammers of said UHF band, which, due to their proximity to GSM commercial bands and other uses, and also due to the size of the jammers (concealable in a pocket), could endanger the correct operation of the high-frequency channel used. The communication unit itself could house the UHF inhibitor detector. The system does not contemplate the use of an jammer detector in the LF/VLF band because the existence of jammers in this band is highly unlikely, aside from being too large to be transported by an individual without being visually identifiable immediately.
The second object of the present invention is an anti-theft asset protection method by means of electromagnetic confinement, using the aforementioned system. Said method comprises the following phases:

configuring the system by sending a configuration and synchronization code, a radiated power code that delimits the confinement space and a surveillance code from the communication unit to each one of the radiant elements through a UHF channel.
creating at least one electromagnetic confinement space by means of the transmission of a surveillance code in a VLF/LF channel from the radiant elements periodically, defining the power with the radiated power code.
programming the protection devices by means of the confinement decoupler by sending an initialization code and a programming code to the protection devices by means of a VLF/LF channel and certain programming parameters by means of a UHF channel;
coupling the protection devices to the assets intended to be protected by means of the anchoring means;
locating the assets to be protected within the electromagnetic confinement space;
checking the reception of the surveillance code when the motion detector is activated, by means of the VLF/LF receiver in the protection devices;
emitting a local sound alarm from the protection device by means of the sound alarm generator and sending a digital alarm through a UHF channel to the communication unit simultaneously, in situations selected between the loss of the surveillance code and the unauthorized opening of the anchoring means of the protection device; and
decoupling the protection devices from the asset to be protected by means of the confinement decoupler.

In a particular embodiment of the invention, for a givenelectromagnetic confinement space, the surveillance code emitted from the radiant elements and the UHF channel used in the communications sent from the protection devices to the communication unit are specific to said confinement space and different from the ones used in another confinement space, allowing the overlap of different confinement spaces without causing interference. Since each target area (each sales department) operates with a specific surveillance code, the specific surveillance code of the area to be covered is sent periodically to the protection devices located therein; if one of them is outside of its natural area (because it is migrated to another one, for example) it will report its migration situation through its UHF channel to the system so the system can react accordingly.
In another particular embodiment of the invention, the communication unit comprises resending the digital alerts received from the radiant elements to the external management and security platform.
In another particular embodiment of the invention, the programming phase of the method is carried out by a user from an external electronic device connected to the decoupler and comprises the following steps:

sending the programming parameters selected between a protection device identifier, a high-frequency channel for the communication between the protection device and the communication unit, the surveillance code and a combination thereof from the electronic device to the decoupler;
sending the initialization code and the programming code to the protection device by means of the VLF/LF channel from the decoupler;
activating the UHF transceiver in the protection device and sending a standby command of the programming parameters to the decoupler;
sending the programming parameters from the decoupler to the protection device by means of the UHF transceiver; and
storing and configuring the protection device with the parameters received.

In another particular embodiment of the invention, the decoupling phase comprises the following steps:

the user introduces its username in the decoupler by means of a user identification connector;
sending an initialization code and a decoupling code from the decoupler to the protection device to be decoupled;
sending a device identifier to the decoupler from the protection device through an UHF channel;
decoupling the anchoring means of the asset's protection device;
sending the decoupled protection device identifier and the user identifier that has carried out the decoupling from the decoupler to the communication unit.

In another particular embodiment of the invention, as a prior phase to the decoupling phase of the method, the communication unit sends a list of the authorized user identifiers to the decoupler.
In another particular embodiment of the invention, in the method alarm emission phase, sending the loss of surveillance code alarm comprises the following phases:

detecting the loss of the surveillance code when the surveillance code is not received within a previously established period of time;
sending the loss of surveillance code alarm;
maintaining the sound alarm inactive while waiting for the reception of an ACK message by the loss of surveillance code alarm sent from the communication unit; and
disconnecting the UHF transceiver from the protection device and activating the sound alarm when the ACK message is received.

In another particular embodiment of the invention, if the ACK message is not received, the alarm is periodically sent until it is received.
In another particular embodiment of the invention, digital alerts selected between the following are sent through a UHF channel from the protection device to the communication unit:

low battery status alert, when the protection device detects a battery level below a previously established threshold;
end of low battery status alert, when the protection device detects a battery level above the previously established threshold after sending a low battery alert;
surveillance code recovery alert, when the protection device detects the surveillance code once again after generating a surveillance code loss alarm;
protection device status alert, sent periodically, the status being selected between decoupled, active, surveying and alarm;
protection device status change alert;
protection device activation alert, when the protection device receives the initialization code sent by the decoupler;
device deactivation alert; and
decoupling alert sent through the decoupler when the protection device is decoupled;

In another particular embodiment of the invention, the communication unit comprises resending the alerts received from the radiant elements, from the decoupler and from the protection devices to the external management and security platform.
In another particular embodiment of the invention, the radiant elements comprise sending alerts to the communication unit when they detect failures selected between:

a short-circuit at the low-frequency LF/VLF transceiver output;
the transceiver is disconnected; and
a failure in the transceiver's power supply.

In another particular embodiment of the invention, a periodical search for UHF jammers is carried out by means of the UHF jammer detector, providing said detector with an alarm in case of finding any active jammer.
In another particular embodiment of the invention, when a protection device receives a surveillance code that does not correspond with the surveillance code of its electromagnetic confinement area, it sends an alarm to the communication unit through its UHF channel specifying the surveillance code received.
Given that the present invention is conceived to protect diverse articles located in several sales departments, it incorporates the necessary functionality to distinguish the operations between the different departments and in particular the displacement situations of articles and protection devices from a department to another.
From the point of view of the regulations to be complied with, the present invention complies with all the applicable regulation related to the transmission levels, the use of the spectrum, the electromagnetic compatibility and specially, the regulation related to people's safety and health.
Finally, the method and system object of the present invention are capable of being integrated to external electronic security platforms available in the market today. This integration allows managing the electromagnetic confinement system as another of the shopping mall's electronic security subsystems, enabling the centralized supervision of its alarms and the subsequent reaction by the mall's security managers.
Each radiant element creates an electromagnetic radiation area around itself, its own area of influence, with a reasonably spherical geometry, little affected by the environment's construction elements, including metals, as well as by the bodies of people who could be present within the coverage area, and having a definable scope between a minimum and a maximum value.
The system object of the present invention contemplates two variants in the physical design of the radiant elements: the ceiling equipment variant, using a circular solenoid surrounding a half-pot ferrite core as an antenna, which is able to transmit more power in comparison to the shelf variant, which uses a solenoid with an air core as an antenna and has more compact physical design.
In another preferred embodiment of the invention, the UHF frequency band used corresponds to the frequencies within the 868-920 MHz band. The selection of the UHF band is mainly determined by its properties to attain good link hauls, due to the small dimensions this band implies for the transmitting antenna to be equipped to the protection devices and the commercial availability of devices that have highly sensitivity receivers, along with a huge dynamic range exceeding 80 dB and a sensitivity exceeding -100dBm, all of which are indispensable to maintain the operation of the UHF link, despite the fact that the protection device is eventually introduced into shielding bags. In another embodiment of the invention the UHF transceiver of the communication unit has a sensitivity higher than -100dBm and a dynamic range higher than 80 dB.
In another embodiment of the invention, the VLF/LF frequency band used corresponds to the frequencies within the 10-125 kHz band. This frequency band presents a large attenuation vs. distance, but it is very uniform and little impacted by the presence of metal objects, people or other electric fields. This feature allows defining the limits of the system object of the present invention in a precise and controlled manner.
In addition, the communication unit controls the different radiant elements so they function in a synchronized manner and with appropriate individual transmission powers, generating a single electromagnetic structure as a whole in the shape and dimensions required by the sale departmentof the articles to be protected. Likewise, this communication unit is in charge of communicating and integrating the electromagnetic confinement system within the external security management system.
On the other hand, each electromagnetic confinement structure or architecture shares a series of common elements for all radiant elements making up and identifying each structure. These distinctive elements are the management of a particular code sequence and the operation of a specific radiofrequency channel in the high-frequency band.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1.- Shows a general perspective of a particular embodiment of the asset protection system object of the present invention.
Figure 2.- Shows a perspective of an embodiment example of the system in which the radiant elements are fixed to the ceiling of a room and the radiating space adapts to the space and geometry thereof.
Figure 3.- Shows a perspective of two physically separate rooms and the confinement spaces generated in each one of them.
Figure 4.- Shows a block diagram of an embodiment example of the internal electronics of a protection device object of the present invention.
Figure 5.- Shows a block diagram of an embodiment example of the internal electronics of a communication unit object of the present invention.
Figure 6.- Shows a block diagram of an embodiment example of the internal electronics of a radiant element object of the present invention.
Figure 7.- Shows a block diagram of an embodiment example of the internal electronics of an electromagnetic confinement decoupler object of the present invention.
Figure 8.- Shows a perspective of a particular embodiment of a protection device with adhesive anchoring elements.
Figure 9.- Shows a perspective of a particular embodiment of a protection device with anchoring elements of the loop type.
Figure 10.- Shows a perspective of a particular embodiment of a protection device with anchoring elements of the spike type.
Figure 11.- Shows a perspective of a particular embodiment of a protection device with threaded anchoring elements.
Figure 12.- Shows a perspective of a particular embodiment of a protection device with anchoring elements adapted to be fixed to cylindrical surfaces.

DESCRIPTION OF AN EXAMPLE OF AN EMBODIMENT OF THE INVENTION

A description of several examples of embodiments of the invention is made below, by way of illustration and not by way of limitation, referring to the numeration adopted in the figures.
An embodiment example of the system object of the invention is detailed below. Figure 1 shows a general view of a particular embodiment of an anti-theft asset protection system based on electromagnetic confinement techniques object of the present invention. Thus, the system (1) comprises a plurality of radiant elements, known as REs hereinafter (2a, 2b), which delimit the electromagnetic confinement area by means of the emission of the corresponding surveillance code from the VLF/LF circuits (6) they integrate. The protection devices, known as tags hereinafter, have a VLF/LF circuit (4) for the reception of the surveillance code and a UHF circuit (5) used to send alarms and alerts to the system. On the other hand, REs also have a UHF circuit (7) to communicate with the communication unit (8). The synchronization between the different REs (2a, 2b) is carried out by means of a RS485 synchronism circuit (9), in which one of the RE (2a) acts as the master and the remaining REs (2b) act as slaves. In turn, the communication unit (8) comprising a UHF transceiver (10) for the reception of alarms and alerts from the tags (3), works as a communications gateway between the system (1) and an external management and security platform (11). The communication between the two is carried out by means of an RS485/Ethernet interface adapter module integrated in the module (13) and connected to the platform (11) by means of an Ethernet driver (14) and a LAN network (15). In addition, the module (13) and the communication unit (8) are connected by means of a RS485 connection (12). The system 1, shown in figure 1, also comprises two decouplers/programmers of tags (16, 19) integrating a UHF circuit for the communication with the communication unit (8) and with the protection devices (3) and a VLF/LF circuit (18) for the exchange of data with the tags (3). The decoupler (16), in this embodiment example, operates in a decoupling mode and the decoupler (19) operates in a programming mode.
The frequency used in the UHF channel is, in this embodiment example, 868 MHz. For the communications in the VLF/LF channel, a 16 KHz frequency is used in this embodiment example.
Figure 2 shows a possible scenario, in which 8 radiant elements fixed to the ceiling of a room (30) generate a confinement space that adapts to the volume and geometry of said room (30). Thus, three of the REs (20, 21, 22) generate confinement spaces corresponding to semi-spheres with a larger diameter than the semi-spheres generated by the other 5 radiant elements (23, 24, 25, 26, 27). Given that the 8 REs are located within a givensales department, all of them emit the same surveillance code, due to which a user would be able to move an asset (28), to which a tag (not shown) is attached, throughout the entire confinement area without triggering the alarm. The alarm would only be triggered if the tag's anchoring means were manipulated or if the user left the room through the exits (29) without previously decoupling the tag from the asset.
Figure 3 shows an embodiment example of two physically separate scenarios (31, 32) that could correspond, for example, to two sales departments at a shopping mall. In a case like this, it is possible that due to the geometric and volumetric conditions of the spaces to be confined, the electromagnetic confinement areas hardly overlap between departments, where part of the confinement space of a department is a little bit introduced into physically adjoining departments. Due to this reason, it has been provided that the surveillance code emitted by the REs (33) of the first department (31) must be different from the surveillance code emitted by the REs (34) of the second department (32). This way, a user moving with the asset (35) to which a tag (not shown) has been attached and staying within the confinement area created inside the first department will not trigger the alarm; even if the user moves through the overlap area (36) in which the confinement area of the second department (32) overlaps with the area created by the first department (31), no alarms would be produced. The same would occur with a user moving with an article (37) within the second department (32) and entering an area (38) in which the confinement area of the first department (31) overlaps with the physical space of the second department (32). Obviously, the alarm will trigger if user gets out from the confined area to which the protection device corresponds.
Figure 4 shows a block diagram of an embodiment example of a tag object of the invention. Thus, the tag is composed by a battery (39) supplying the internal electronics, a microprocessor (40) controlling the rest of the components and integrating a UHF transceiver. The microprocessor (40) is connected to the UHF antenna (41) from which the alarms are sent. It also manages the information received from the motion detector (42), from the tamper (43) and communicates with the local sound alarm (44). In addition, the microprocessor (40) comprises being connected to the VLF/LF transceiver (45), which, in turn, is connected to a VLF/LF antenna circuit composed by 3 antennae, each one of which is oriented in a spatial axis. Thus, the tag is kept idle with the battery (39) being disconnected, reducing consumption and extending the life of the device, until the motion detector (42) detects that the asset, along with the tag, are moving.
Then, the internal electronics are activated and they begin searching for the surveillance code by means of the VLF/LF transceiver (46). If the code is not received, the local sound alarm (44) is triggered and the UHF transceiver would send a digital alarm through the UHF antenna circuit (41) to the communication unit. Likewise, if the tamper (44) were manipulated, an alarm signal that would activate the local alarm (44) and the UHF transceiver (43) could be emitted.
Figure 5 shows a block diagram of an embodiment example of a communication unit. Said unit comprises a power supply circuit (48), a RS485 adapter module (49) to communicate with the management and security platform. Said module (49) uses the RS485 bus driver (50) to communicate with the microprocessor (51). This microprocessor has a UHF transceiver integrated to send and receive communications at high frequencies UHF through the UHF antenna circuit (52).
In addition, it integrates an alarm driver (53) to manage the electronic alarms received from the tags.
Figure 6 shows a block diagram of an embodiment example of a radiant element. Said radiant element comprises a power supply circuit (54), a RS485 adapter circuit (55) to manage the synchronism channel connected to the microprocessor (59) and an electronic control module (57) by means of a RS485 driver (56). It also has a UHF transceiver integrated to the microprocessor. It also comprises a current probe (64), connected to the power supply circuit (54) which is connected to the microprocessor (59) and the VLF/LF power driver circuit (60). This power driver circuit (60) supplies a VLF/LF power amplifier, which in turn, supplies the VLF/LF antenna, determining the radiating power of the same and therefore the confinement space generated by the radiant element.
Figure 7 shows an embodiment example of the internal electronics of an electromagnetic confinement decoupler. The decoupler uses a support-base (65) connected directly to the network by means of a plug or a similar element (66). The base (65) is directly connected to a battery-charging module (67), which is in turn connected to a power supply circuit (68). In addition, it has a USB connector (69) for the introduction of external memories connected to a UART/USB interface adapter module (70). The decoupler also comprises a microprocessor (72) connected to a username-reader connector (71), to the UART/USB interface adapter module (70) and to the VLF/LF antenna (74) by means of a VLF/LF amplifier.
On the other hand, figures 8 to 11 show various embodiment examples of the anchoring means of the protection devices. Thus, figure 8 specifically shows the upper part of the tag's housing (75) and the lower part of the housing (76), within which the electronics associated to the tag are introduced. The anchoring means comprise being adhesives to be stucked to the surface of the asset to be protected. The lower housing (76) presents, in addition to the orifices (77) for the refrigeration of the internal electronics and the sound output for the local alarm, an overhang (78) acting as support having a ring-shaped perimetral flange (80) to which a platform (78) is fixed. The flange (80) is fixed to said platform by means of actionable tabs (81). The adhesive means (79) are finally located on the platform (78).
Figure 9 shows another embodiment example in which the anchoring means are a loop. The loop fixed to the tag's lower housing (76) comprises a cable (82) and an anchoring element (83) located on the cable's free extremity (82) which is fixed to the lower housing (76) in correspondence with a box (84) existing therein.
Figure 10 shows another embodiment example in which the anchoring means are a spike (85) and the corresponding base (86) to which the spike (85) is inserted. Thus, the lower housing (76) presents an overhang (87) to which an extremity of the spike (85) is anchored. The opposite free extremity is introduced in the base (86) and is fixed therein by means of a spike retention device (87).
Figure 11 shows another embodiment example in which the anchoring means have been designed to be introduced into screwed orifices of the assets to be protected. Thus, the tag's lower housing (76) comprises an overhang (88) with a ring-shaped perimetral flange (89), to which a platform (91) comprising screwed means (92) for their introduction into orifices is coupled by means of a tab (90).
Figure 12 shows an embodiment example of anchoring elements designed to be stuck to cylindrical elements, preferably bottles. This is an open section profile (93), adaptable to the body or neck of a bottle. It also comprises a lateral extension (94) as a guide to fix the tag's housing (75, 76).

Claims

An anti-theft asset protection system by means of electromagnetic techniques, comprising at least one asset to be protected, characterized in that it comprises at least the following elements:
- at least one radiant wireless element comprising a UHF transceiver to send and receive communications to and from a communication unit, a VLF/LF emitter to send a radiofrequency signal to at least one wireless asset protection device, delimiting the radiated power of the radiofrequency signal an electromagnetic confinement space and the asset under protection being located within the generated confinement space;

- at least one wireless asset protection device fixed to the asset to be protected through an anchoring means that comprises a sound alarm generator, a microprocessor, a motion detector, a VLF/LF receiver to receive the radiofrequency signal originating from at least one radiant element, a UHF transceiver to communicate the protection device to an electromagnetic confinement decoupler and to send alarms and alerts from the protection device to the communication unit;

- a communication unit, comprising a UHF transceiver to receive communications originating from at least one protection device and to send and receive configuration parameters with at least one radiant element and with an electromagnetic confinement decoupler and comprising connection means with an external management and security platform through which alarms and alerts generated in the asset protection system are sent and the configuration commands of the asset protection system are received;

- an electromagnetic confinement decoupler comprising a UHF transceiver to communicate with the communication unit and a VLF/LF transceiver to send commands to the protection device, programming and decoupling the protection devices by means of the UHF transceiver and the VLF/LF transceiver of the decoupler; and

- at least one UHF jammer detector, which allows checking the existence of jammers of said UHF band.
The anti-theft asset protection system, according to claim 1, characterized in that the at least one radiant element comprises
• at least one modular power driver circuit, managing the transmission power of the VLF/LF emitter; and,

• a synchronism channel used to send and receive a synchronism frame between the radiant elements.
The anti-theft asset protection system, according to claim 2, characterized in that the communication unit comprises remote management means of the modular power driver circuit of each radiant element independently.
The anti-theft asset protection system, according to any one of the preceding claims, characterized in that the VLF/LF receiver of the protection devices comprises three antennae, each of which is oriented towards one of the spatial axes, decreasing the uncertainty related to the spatial orientation of the protection device.
The anti-theft asset protection system, according to any one of the preceding claims, characterized in that the electromagnetic confinement decoupler at least comprises
• one control module, governed by a microcontroller,

• a user identification connector,

• a memory storing at least one list of authorized users,

• a USB connector and a power supply, and

• power supply means.
The anti-theft asset protection system, according to claim 2, characterized in that, a first radiant element comprises means of control and management to synchronize the remaining radiant elements, being carried out the synchronization by sending the synchronism frame from the first radiant element towards the remaining radiant elements through means selected between an UHF synchronism channel and an RS485 interface.
The anti-theft asset protection system, according to any one of the preceding claims, characterized in that the anchoring means are selected between:
- adhesives to be fixed on the asset to be protected and a contact activating the protection device when pressed;

- at least one cable, as a loop, fixed by one of its extremities to the protection device and comprising fastening means to the device by its opposite extremity, remaining fixed to the asset to be protected by means of the introduction of the cable through an orifice of the asset and activating the protection device by fixing the fastening means to the device, closing the loop;

- at least one spike to be introduced inside an orifice of the asset, fixed by means of a closing cap inserted in the spike, closing the contact by introducing the spike activating the protection device;

- a hoop to fix the assets to cylindrical elements with a contact which, when pressed, activates the protection device;

- dovetailing fixing means ending in a screw activating the protection device when reaching a stop; and

- a combination thereof.
An anti-theft asset protection method by means of electromagnetic confinement, for carrying out the system described in any one of the preceding claims, characterized in that it comprises the following phases:
i) configuring the system by sending a configuration and synchronization code, a radiated power code that delimits the confinement space and a surveillance code from the communication unit to each one of the radiant elements through a UHF channel;

ii) creating at least one electromagnetic confinement space by means of the transmission of a surveillance code in a VLF/LF channel from the radiant elements periodically, defining the power with the radiated power code;

iii) programming the protection devices by means of the confinement decoupler by sending an initialization code and a programming code to the protection devices by means of a VLF/LF channel and certain programming parameters by means of a UHF channel;

iv) coupling the protection devices to the assets intended to be protected by means of the anchoring means;

v) locating the assets to be protected within the electromagnetic confinement space;

vi) checking the reception of the surveillance code when the motion detector is activated, by means of the VLF/LF receiver in the protection devices;

vii) emitting a local sound alarm from the protection device by means of the sound alarm generator and sending a digital alarm through a UHF channel to the communication unit simultaneously in situations selected between the loss of the surveillance code and the unauthorized opening of the anchoring means of the protection device;

viii) decoupling the protection devices from the asset to be protected by means of the confinement decoupler; and,

ix) detecting the existence of UHF jammers by means of the UHF inhibitor detector.
The anti-theft asset protection method, according to claim 8, caractherized in that for a given electromagnetic confinement space, the surveillance code emitted from the radiant elements and the UHF channel used in the communications sent from the protection devices to the communication unit are specific to said confinement space and different from the ones used in another confinement space, allowing the overlap of different confinement spaces without causing interference.
The anti-theft asset protection method, according to claim 9, characterized in that the selection of the UHF channel used in the communications sent from the protection devices to the communication unit together with the dynamic range and the sensitivity of the UHF transceiver of the communication unity, generate a radio electric link that works when the asset to be protected and the protection device are introduced inside of a metal bag.
The anti-theft asset protection method, according to claim 8, characterized in that the communication unit comprises resending the digital alarms received from the radiant elements to the external management and security platform.
The anti-theft asset protection method, according to claim 8, characterized in that the programming phase of the method is carried out by a user from an external electronic device connected to the decoupler and comprises the following steps:
- sending the programming parameters selected between a protection device identifier, a high-frequency channel for the communication between the protection device and the communication unit, the surveillance code and a combination thereof from the electronic device to the decoupler;

- sending the initialization code and the programming code to the protection device by means of the VLF/LF channel from the decoupler;

- activating the UHF transceiver in the protection device and sending a standby command of the programming parameters to the decoupler;

- sending the programming parameters from the decoupler to the protection device by means of the UHF transceiver; and

- storing and configuring the protection device with the parameters received.
The anti-theft asset protection method, according to any one of the preceding claims, wherein a list of the authorized user identifiers has been previously sent by the communication unit to the decoupler, characterized in that the decoupling phase comprises the following steps:
- the user introduces its username in the decoupler by means of a user identification connector;

- sending an initialization code and a decoupling code from the decoupler to the protection device to be decoupled;

- sending a device identifier to the decoupler from the protection device through an UHF channel;

- decoupling the anchoring means of the asset's protection device; and,

- sending the decoupled protection device identifier and the user identifier that has carried out the decoupling from the decoupler to the communication unit.
The anti-theft asset protection method, according to any one of the preceding claims, characterized in that a periodical search for UHF jammers is carried out by means of the UHF jammer detector, providing said detector with an alarm in case of finding any active jammer.
The anti-theft asset protection method, according to any one of the preceding claims, characterized in that when a protection device receives a surveillance code that does not correspond with the surveillance code of its electromagnetic confinement area, it sends an alarm to the communication unit through its UHF channel specifying the surveillance code received.