SYSTEM USING RFID TECHNOLOGY FOR INVENTORY OF OBJECTS IN A SPACE LIMITED BY AN ENCLOSURE

Abstract

The invention relates to an inventory system for objects (OMT1, OMTN) contained within an enclosed space delimited by a barrier. The system comprises a control device (100) connected to a UHF RFID reader (250) located within the enclosed space. The UHF RFID reader is equipped with at least one antenna that emits electromagnetic waves to RFID tags (Puc1, PucN) affixed to the objects, each object having a predetermined position within the enclosed space. According to the invention, at least one of the predetermined positions comprises an auxiliary radiating element (Era1, EraN) for electromagnetic waves. Fig. 2

Description

Title of the invention: SYSTEM USING RFID TECHNOLOGY FOR INVENTORY OF OBJECTS IN A LIMITED SPACE BY A SPEAKER Technical field

[0001] The present invention relates to a system using RFID technology for inventorying objects contained in a space limited by an enclosure. STATE OF PRIOR ART

[0002] Systems for inventorying objects contained in a limited space using RFID technology are known. Generally, a system using RFID technology consists of three types of elements:

[0003] - at least one transponder, also called a tag, consisting of an electronic circuit provided of an antenna for transmitting and receiving data in the form of radiofrequency waves, the circuit comprising at least one memory in which an identifier of said transponder is stored,

[0004] - a reading point also consisting of an electronic circuit provided with an antenna to transmit and receive data also in the form of radio frequency waves, and

[0005] - a control unit connected to the reading point and implementing an application.

[0006] The operation of such an RFID system is as follows. At the start of the identification procedure, the reading point emits a modulated electromagnetic wave, subsequently called a wake-up wave, to each tag in the system. Upon receipt, a tag, located in a coverage area where the electromagnetic field generated by the reading point is at a sufficiently high level, is electrically powered by the electromagnetic wave, comes out of its standby state, becomes active and then emits identification data specific to it in the form of a modulated electromagnetic wave. This identification data is received by the reading point which then proceeds to identify the tag in question.

[0007] In the application to an inventory system envisaged here, each tag is attached to an object, such as a tool used for the maintenance of a workshop, a factory, etc. The objects to be inventoried are stored in an enclosed space, such as a piece of furniture, a trolley, a cupboard. This enclosed space is subdivided into a plurality of enclosed sub-spaces such as, for example, shelves, drawers, etc.

[0008] Several technological developments have emerged in recent years to make RFID technology more efficient and discreet. Tags have been miniaturized, the configuration of the tags' antennas has been modified to be able to be used on metal objects or surfaces such as plastic, rubber and sensitivity RFID readers have been improved.

[0009] RFID tags currently have a size not exceeding 40mm3 and have miniature antennas which lead to a significant drop in their gain.

[0010] It is then difficult to detect objects with RFID tags in closed enclosures with a large volume. Statement of the invention

[0011] To this end, the invention relates to a system for inventorying objects contained in an enclosed space delimited by an enclosure, the system comprising a control device connected to a UHF RFID reader arranged in the enclosed space, the UHF RFID reader being provided with at least one antenna which emits electromagnetic waves to RFID tags arranged on the objects, the objects each having a predetermined position in the enclosed space, characterized in that at least part of the predetermined positions comprises an auxiliary radiating element of electromagnetic waves.

[0012] Thus, the present invention makes it possible to strengthen the electromagnetic fields around the tagged metal objects, leading to an improvement in the detection of the object. Furthermore, the invention, by using auxiliary radiating elements, offers a possibility of adapting the design according to the need and ease of implementation.

[0013] According to a particular embodiment, the auxiliary radiating element consists of two trapezoidal-shaped branches and two load bars each comprising a notch.

[0014] Thus, the invention makes it possible to improve the detection rate of the tagged object in a closed metallic space. The proposed pattern provides more flexibility in the positioning of the object by having performances less sensitive to the angular direction of the tag and in the optimization of the antenna.

[0015] According to a particular embodiment, a trapezoidal-shaped branch comprises three recesses arranged on the largest side of the trapezoidal shape.

[0016] Thus, the present invention, by having an asymmetrical shape, aims to expand the operating range of the solution in the ETSI and FCC bands by having a wide band or multi-bands. In addition, the solution will also make it possible to reduce the dimension of the auxiliary radiating element.

[0017] According to a particular embodiment, a trapezoidal-shaped branch comprises two recesses, each recess being respectively on one side of the trapezoidal shape.

[0018] Thus, the present invention, by having an asymmetrical shape, aims to expand the operating range of the solution in the ETSI and FCC bands by having a wide band or multi-bands. In addition, the solution will also reduce the dimension of the auxiliary radiating element. Brief description of the drawings

[0019] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of exemplary embodiments, said description being made in relation to the attached drawings, among which:

[0020] [Fig-1] is a schematic view of a maid's inventory system in which the present invention is implemented;

[0021] [Fig.2] is an example of the architecture of the inventory system according to the present invention;

[0022] [Fig.3] illustrates the operating principle of the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention;

[0023] [Fig.4] is a first example of embodiment of the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention;

[0024] [Fig.5] is a second exemplary embodiment of the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention;

[0025] [Fig.6] is a first exemplary embodiment of an auxiliary radiating element of electromagnetic waves used in the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention;

[0026] [Fig.7] is a second exemplary embodiment of an auxiliary radiating element of electromagnetic waves used in the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention;

[0027] [Fig.8] is a third exemplary embodiment of an auxiliary radiating element of electromagnetic waves used in the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0028] DETAILED DESCRIPTION OF EMBODIMENTS

[0029] [Fig.l] is a schematic view of an inventory system according to a first embodiment of the present invention.

[0030] The inventory system shown in [Fig.l] is intended to inventory objects which are contained in an enclosed space such as a piece of furniture 10, a cupboard or a workshop trolley, which may contain elements such as shelves, drawers, etc. forming enclosed sub-spaces. This enclosed space and these enclosed sub-spaces are respect- specifically delimited by a metal enclosure.

[0031] The objects in question are, for example, tools for ensuring the maintenance of a workshop, a factory, etc. These objects are provided with an RFID tag (Radio Frequency IDentification).

[0032] The inventory system comprises a control device 100.

[0033] [Fig.2] is an example of the architecture of the inventory system according to the present invention.

[0034] The control device 100 is connected to a UHF RFID reader 250 arranged in the enclosed space 10. The UHF RFID reader 250 is provided with at least one antenna (not shown) which emits electromagnetic waves to RFID tags. The control device 100 is, for example, a computer, a smartphone, a touch tablet.

[0035] The objects contained in the enclosed space each have a predetermined position, thus allowing the control device to determine whether or not each object is present in the enclosed space.

[0036] At least a portion of the predetermined positions comprises an auxiliary radiating element of electromagnetic waves according to the invention.

[0037] For example, in the drawer Tir, at the predetermined positions of the objects OMTi to 0MTn comprising a tag Puci, to PucN, the auxiliary radiating elements Erai to EraN are arranged.

[0038] [Fig. 3] illustrates the operating principle of the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0039] The UHF RFID reader 250 is provided with at least one antenna (not shown) which emits electromagnetic waves to RFID tags. The electromagnetic waves are received by the auxiliary radiating element Era. When the auxiliary radiating element Era receives energy in the form of electromagnetic waves, the energy induces a current I&a which generates an intense magnetic field HEra. The presence of the object OMT comprising an RFID tag in the intense magnetic field introduces an inductive current I0Mt inside the object, which makes it possible to power the RFID tag.

[0040] The higher the density of the magnetic field HEra, the greater the power received by the RFID tag. The signal received by the RFID tag is reinforced, thus increasing the reading range of the UHF RFID 250 reader.

[0041] [Fig.4] is a first example of an embodiment of the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0042] In the example of [Fig.4], a predetermined position comprises an element Era auxiliary radiant according to the invention.

[0043] The Era auxiliary radiating element is arranged on a substrate, for example of the FR4 type, 1.6 mm thick, resting on a GND ground plane.

[0044] The OMT object comprising an RFID tag Pue is arranged above the auxiliary radiating element Era.

[0045] In [Fig.4], the RFID tag Pue is arranged opposite the auxiliary radiating element Era.

[0046] Depending on the shape of the Era auxiliary radiating element, the Pue RFID tag can be arranged in a different orientation, thus allowing the OMT object to be arranged in any orientation, provided that the object is placed above the auxiliary radiating element.

[0047] [Fig. 5] is a second exemplary embodiment of the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0048] In the example of [Fig.5], a predetermined position comprises an auxiliary radiating element Era according to the invention.

[0049] The auxiliary radiating element Era is arranged on a substrate Sub resting on a ground plane GND.

[0050] The OMT object comprising an RFID tag Pue is arranged above the auxiliary radiating element Era.

[0051] In order to ensure good positioning of the OMT object comprising an RFID tag, a foam, shaped to be adapted to the shape of the OMT object intended to be placed in the predetermined position, is arranged above the Era auxiliary radiating element.

[0052] The foam is made of a material permeable to electromagnetic waves, for example polyurethane. This material has a permittivity of 1.03 to 1.21 for the frequency band below 10 GHz. Thus, the foam is completely transparent to the propagation of electromagnetic waves.

[0053] In [Fig.5], the RFID Pue tag is arranged opposite the radiating element auxiliary Era.

[0054] Depending on the shape of the Era auxiliary radiating element, the Pue RFID tag can be arranged in a different orientation, thus allowing the OMT object to be arranged in any orientation, provided that the object is placed above the auxiliary radiating element.

[0055] [Fig.6] is a first example of an embodiment of an auxiliary radiating element of electromagnetic waves used in the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0056] The Era auxiliary radiating element consists of two branches of tra Tral and Tra 2 zoidal and two load bars Bel and Bc2 each having a notch. The length of the two bars Bel and Bc2 and the width of the notch are 52 mm and 0.4 mm, respectively. The width of the bars is measured at 2 mm. The proposed configuration allows to optimize the radiating structure, which makes an improvement in detection of the tagged object in different directions.

[0057] [Fig.7] is a second exemplary embodiment of an auxiliary electromagnetic wave radiating element used in the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0058] The auxiliary radiating element Era consists of two trapezoidal branches Tral and Tra 2 and two load bars Bel and Bc2 each comprising a notch. In the example of [Fig.7], the trapezoidal branch Tra2 has three recesses arranged on the largest side of the trapezoidal shape. These recesses make it possible to adjust the bandwidth of the auxiliary radiating element Era.

[0059] [Fig.8] is a third exemplary embodiment of an auxiliary electromagnetic wave radiating element used in the improved system for inventorying objects contained in a limited space using RFID technology according to the present invention.

[0060] The auxiliary radiating element Era consists of two trapezoidal branches Tral and Tra 2 and two load bars Bel and Bc2 each comprising a notch. In the example of [Fig.8], the trapezoidal branch Tra2 comprises two recesses, each recess being respectively on one side of the trapezoidal shape. These recesses make it possible to adjust the bandwidth of the auxiliary radiating element Era.

Claims

Claims

1. System for inventorying objects (OMTi, OMTN) contained in an enclosed space delimited by an enclosure, the system comprising a control device (100) connected to a UHF RFID reader (250) arranged in the enclosed space, the UHF RFID reader being provided with at least one antenna which emits electromagnetic waves to RFID tags (Puci, PucN) arranged on the objects, the objects being intended to be placed respectively at a predetermined position in the enclosed space, at least part of the predetermined positions comprising an auxiliary radiating element (Erai, EraN) of electromagnetic waves, characterized in that the auxiliary radiating element consists of two trapezoidal branches and two load bars each comprising a notch.

2. System according to claim 1, characterized in that a trapezoidal-shaped branch has three recesses arranged on the largest side of the trapezoidal shape.

3. System according to claim 1, characterized in that a trapezoidal-shaped branch comprises two recesses, each recess being respectively on one side of the trapezoidal shape.

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