WO2023073291A1

WO2023073291A1 - Reflection device with one or more metasurfaces for an identification-element detection device

Info

Publication number: WO2023073291A1
Application number: PCT/FR2022/051742
Authority: WO
Inventors: Laurent Barre; Valerie BRULHARD; Denis Albert DELPORTE; Pascal DUVERGER
Original assignee: Psa Automobiles Sa
Priority date: 2021-10-27
Filing date: 2022-09-15
Publication date: 2023-05-04
Also published as: EP4423853A1; FR3128591B1; FR3128591A1

Abstract

A reflection device (DR) forms part of a detection device (DD) fitted to a system (S), comprising a closed space (EF) with a metal environment and comprising an object (O) equipped with an identification element (EI) that transmits/receives waves, and comprising an identification reader (LI) that exchanges messages with the identification element (EI), via an antenna (AER) that transmits/receives waves and is installed in the closed space (EF), in order to detect the presence of said identification element. This reflection device (DR) comprises at least one metasurface that reflects waves from the antenna (AER) that are destined for the identification element (EI) and vice versa, and a main wall installed in the closed space (EF) at a first distance from a support wall (PSS), with the metasurface being interposed at second and third distances from the main wall and support wall (PSS), respectively, the metasurface being made of an electrically non-insulating material and allowing the waves to pass without modifying their waveform.

Description

DESCRIPTION

TITLE: REFLECTION DEVICE WITH METASURFACE(S) FOR AN IDENTIFICATION ELEMENTS DETECTION DEVICE

5 Technical field of the invention

The present invention claims the priority of French application 2111396 filed on 27.10.2021, the content of which (text, drawings and claims) is incorporated herein by reference. The invention relates to reflection devices with metasurface(s) which are intended to form part of detection devices fitted to systems comprising at least one closed space with a metallic environment and comprising at least one object to be detected.

State of the art

Certain systems, such as for example certain vehicles (possibly5 commercial vehicles or trucks), comprise at least one closed space in which can be housed, more or less temporarily, objects provided with a transmitter/receiver identification element. waves intended to allow their detection by an on-board detection device.

This detection device comprises an identification reader responsible for exchanging messages with the identification elements of the objects present in the closed space via at least one antenna transmitting/receiving waves which may optionally be part of a box. of the detection device. Generally, the waves emitted by the wave emitter/receiver antenna and the identification elements have frequencies5 belonging to the radiofrequency (RF) domain, and the identification elements are radio identification tags (or markers) frequency comprising an electronic chip associated with an RF antenna. This is called radio frequency identification (or RFID (“Radio Frequency Identification”)). 0 When the space is closed off to a metallic environment, such as when defined by a vehicle or trailer body, object detection often does not work well or not at all due to the presence of an obstacle (possibly another object) or an electromagnetic disturbance produced by the vehicle or a collision of RF waves. It may also happen that the detection device detects the identification element of an object situated outside the closed space.

5 This detection problem, resulting not only from the positioning of the antenna transmitting/receiving waves relative to the objects in the closed space but also from the configuration and the metallic environment of the latter, it has been proposed, in particular in the patent document FR 3103327, to add to the detection device at least one metasurface configured so as to reflect waves coming from the antenna and intended for the identification elements and waves coming from the identification elements and intended to the antenna.

Here, the term "metasurface" means a surface having a thickness less than the wavelength of the waves that it must reflect and produced5 in a structured metamaterial (with horizontal patterns having a size less than the aforementioned wavelength) or unstructured. A metamaterial is an artificial composite material with electromagnetic properties not possessed by a natural material, and in particular an ability to modulate the behavior of electromagnetic waves0 thanks to specific boundary conditions. Note that a metasurface can be programmable or non-programmable. A detection device with metasurface(s) makes it possible to notably improve detection. However, the metasurfaces being generally fixed on one or more support walls of the closed space, they are exposed both physically and electromagnetically, and therefore they can be damaged (and consequently rendered inoperative) and/or disturbed in particular by beams nearby electrical (and therefore less efficient). The problem of physical damage requires placement in a very little or no exposed area of the closed space, which makes them less effective. The problem of electromagnetic disturbance requires many time-consuming and expensive positioning tests to be carried out, and the optimal (undisturbed) positions found are very rarely compatible with good physical protection and with optimum detection efficiency.

Furthermore, the presence of windows and/or seals, in particular in utility vehicles, can lead to a loss of detection performance of the detection device.

5 The aim of the invention is therefore in particular to improve the situation.

Presentation of the invention

In particular, it proposes a reflection mechanism for this purpose:

- intended to form part of a detection device, on the one hand, intended to equip a system comprising a closed space with a metallic environment and comprising at least one object provided with a wave transmitter/receiver identification element, and, on the other hand, comprising an identification reader exchanging messages with the identification element, via at least one antenna transmitting/receiving waves and intended to be installed in the closed space, in order to detect its presence, and

- comprising at least one metasurface configured so as to reflect waves coming from the antenna and intended for the identification element and waves coming from the identification element and intended for the antenna.

This reflection device is characterized in that it also comprises a main wall intended to be installed in the closed space at a first chosen distance from a support wall partially delimiting this closed space with interposition of the (each) metasurface at second and third distances chosen respectively from the main wall and the support wall, made of an electrically non-insulating material and allowing the waves to pass without changing their waveform.

Thus, the main wall physically protects the metasurfaces while allowing waves to pass in both directions without disturbing them, and the metasurfaces are not in contact with either the main wall PP or the support wall so as not to be disturbed and thus ensuring their proper functioning. Consequently, the invention makes it possible to very significantly increase the probability of identifying objects present in a closed space with a metallic environment.

The reflection device according to the invention may comprise other characteristics which may be taken separately or in combination, and in particular:

- it may include an insulation part intended to be inserted between the metasurface and the support wall and made of an insulating material

5 electrically;

- it may comprise at least one spacer installed between the main wall and metasurface(s) and made of an electrically non-insulating material, and having a thickness equal to the second distance chosen;

- in the presence of the last option, the spacer can be an added piece of foam or a protrusion forming an integral part of the main wall;

- the second distance may be greater than or equal to 1.5 mm;

- the main wall may have a thickness less than or equal to 2.5 mm at least opposite an electrical part of (each) metasurface;

- it may comprise a box intended to be fixedly secured to the support wall, in which the metasurface is fixedly installed, and comprising the main wall and side walls fixedly secured to the main wall, made of the same material as the latter, and surrounding the metasurface.

The invention also proposes a detection device, on the one hand, intended to equip a system comprising a closed space with a metallic environment and comprising at least one object provided with a wave transmitter/receiver identification element, and, on the other hand, comprising an identification reader exchanging messages with the identification element, via at least one antenna transmitting/receiving waves and intended to be installed in the closed space5, in order to detect its presence.

This detection device is characterized in that it also comprises at least one reflection device of the type presented above and intended to be fixedly secured to a support wall partially delimiting the closed space of the system. 0 For example, this detection device may comprise at least two reflection devices intended to be fixedly secured to the same support wall partially delimiting the closed space or else to different support walls and partially delimiting the closed space. Also for example, the waves emitted may have frequencies which belong to the radio frequency range, or alternatively may be photons.

The invention also proposes a system comprising a closed space,

5 metallic environment and capable of comprising at least one object provided with a wave transmitter/receiver identification element, as well as at least one detection device of the type presented above.

For example, this system can constitute a vehicle.

Also for example, this system can comprise an outer wall defining a support wall, and an inner wall installed at the first chosen distance from this outer wall, defining a main wall of at least one reflection device, and participating in the delimitation of its closed space. It will be noted that an intermediate piece, defining the piece of insulation of at least one reflection device, can be installed between the external and internal walls.

Brief description of figures

Other characteristics and advantages of the invention will become apparent on examination of the detailed description below, and of the appended drawings, in which: [Fig. 1] schematically and functionally illustrates an example of a truck comprising a closed space comprising objects provided with identification elements and a detection device comprising two reflection devices according to the invention, connected in series,

[Fig. 2] schematically and functionally illustrates, in a sectional view,5 a first embodiment of a reflection device according to the invention, secured to a support wall of a system,

[Fig. 3] schematically and functionally illustrates, in a sectional view, a second embodiment of a reflection device according to the invention, secured to a support wall of a system, 0 [Fig. 4] illustrates schematically and functionally, in a sectional view, a third embodiment of a reflection device according to the invention, secured to a support wall of a system,

[Fig. 5] illustrates schematically and functionally, in a side view perspective, part of an exemplary embodiment of a detection device comprising three reflection devices according to the invention, connected in series and coupled to the computer of the identification reader, and

[Fig. 6] schematically and functionally illustrates an example of a truck

5 with refrigerated box delimiting a closed space comprising objects provided with identification elements and a detection device comprising two reflection devices according to the invention, connected in series and some elements of which are sub-parts of the refrigerated box.

Detailed description of the invention

The object of the invention is in particular to propose a reflection device DR intended to form part of a detection device DD, itself intended to equip a system S, comprising a closed space EF having a metallic environment and in which can be placed O5 objects each provided with an identification element El transmitter / receiver of waves to detect their presence.

In what follows, it is considered, by way of non-limiting example, that the system S is a vehicle. This is for example a truck, as illustrated without limitation in Figures 1 and 6. But the invention is not limited to this type of system. It relates in fact to any type of system comprising at least one closed space having a metallic environment and in which objects provided with a wave emitter/receiver identification element can be placed. Thus, it concerns land vehicles (and in particular utility vehicles and trucks (with or without a trailer)), boats, aircraft, safes, buildings and installations (possibly industrial).

There is schematically shown in Figure 1 a system S (here a truck) comprising a closed space EF having a metallic environment and comprising objects O each provided with an identification element El and an example embodiment of a device for detection DD according to the invention comprising two reflection devices DR according to the invention, connected in series.

In the example illustrated in FIG. 1, the system S is a vehicle, and more precisely a truck comprising a body CS, fixedly secured to its frame, at least partially metallic, and defining a closed space EF to which access is controlled by at least one door PCS. It will be noted that the CS box could be part of a trailer.

The objects O housed in the closed space EF can be of any type. So,

5 it may be, for example, packets (or parcels) to be transported or equipment (such as tools (drill, screwdriver, grinder, electric saw, etc.)). It will be noted that the invention applies when there is at least one object O present in the closed space EF and equipped with an identification element El transmitter/receiver of waves.

A wave emitter/receiver identification element El comprises a wave emitter/receiver antenna associated with an electronic chip which is on standby most of the time and is awakened and energized by specific waves which it receives from an antenna AER associated with an identification reader L1 of a detection device DD. This electronic chip5 stores at least one identifier which represents the object O with which it is associated.

As illustrated in FIGS. 1 and 6, a detection device DD, according to the invention, comprises an identification reader L1, at least one antenna AER emitting/receiving waves, and at least one reflection device DR0 with metasurface (s) MS, according to the invention.

The antenna (each antenna) AER is intended to be installed in the enclosed space EF. It will be noted that it can be part of the housing of the identification reader L1, as in the examples illustrated without limitation in FIGS. 1 and 6. But this is not obligatory. Indeed, it can be remote (or remote) from the housing of the identification reader L1, while being coupled to the latter (L1), for example via a cable.

In the examples illustrated without limitation in FIGS. 1 and 6, the detection device DD only comprises a single antenna AER, but it could comprise at least two. The number of antennas AER of a detection device DD depends on the layout of the closed space EF and/or of each zone where an object O is stored to be detected by this detection device DD, but also of each place where a reflection device DR of this detection device DD.

It will be noted that in the examples illustrated without limitation in FIGS. 1 and 6, the antenna AER is installed on a front and substantially vertical wall of the body CS of the vehicle S, and the reflection devices DR are

5 installed on (or in) a wall defining the roof T of the body CS of the vehicle S. But in other systems S the antenna AER could be installed on a side or rear wall and substantially vertical or defining the roof T of the body CS of the vehicle S, and the reflection devices DR could be installed on (or in) a wall defining the roof T or lateral or front and substantially vertical of the body CS of the vehicle S.

It will also be noted that in the examples illustrated without limitation in FIGS. 1 and 6, the antenna AER is installed substantially parallel to the front wall of the body CS. However, it could be inclined with respect to this front wall (or any other wall of the box CS which supports it). The inclination should not be too great in order to reduce bulk and not expose the AER antenna too much to shocks. For example, this inclination is less than 30°.

It will also be noted that each antenna AER is preferably installed0 at a distance from an electrical harness of the body CS which is at least equal to 50 mm. When this is not possible, it is preferable to shield the neighboring wiring harness.

The identification reader Ll is arranged to exchange messages with each identification element El present in the closed space EF, via the antenna AER, in order to detect its presence. For example, it can be arranged to determine whether objects O are absent in the closed space EF by comparing the identifiers received from the identification elements El with a stored list of identifiers, or only to record all the identifiers received from the elements identification El, or to compare un0 previous loading with the current loading, or to alert when an element of identification El is no longer present in the closed space the EF.

In what follows, it is considered, by way of non-limiting example, that the waves emitted by the antenna AER and by each identification element El have frequencies belonging to the radio frequency (or RF) domain. Therefore, radio frequency identification (or RFID (Radio Frequency Identification)) is carried out here. But the invention is not limited to waves

5 belonging to the field of radio frequencies. It concerns any frequency range that is not dangerous for humans. Thus, the identification waves can be photons.

As illustrated in FIGS. 1 to 6, a reflection device DR, according to the invention, comprises at least one metasurface MS and one main wall PP.

The (each) metasurface MS is configured so as to reflect waves which come from the antenna AER and are intended for one (each) identification element El of an object O and vice versa (namely waves coming from a (of each) identification element El and intended for the antenna AER). 5 Therefore, the (each) MS metasurface acts as a two-way wave relay.

It is recalled that the term "metasurface" here means a surface having a thickness less than the wavelength of the waves that it must reflect and made of a metamaterial which can be structured with horizontal patterns having a size less than the aforementioned wavelength or unstructured. A metamaterial is an artificial composite material with electromagnetic properties not possessed by a natural material, and in particular an ability to modulate the behavior of electromagnetic waves thanks to specific boundary conditions. Note that an MS metasurface can be programmable or non-programmable. It will also be noted that a metasurface MS can optionally be configured so as to reflect according to at least a first chosen law the waves coming from the antenna(s) AER and intended for each identification element El and according to at least a second law chosen0 the waves coming from each identification element El and intended for the antenna(s) AER. It will also be noted that in the presence of at least two reflection devices DR, the metasurface(s) MS of a reflection device DR can possibly have a first law of reflection and/or a second law of reflection different from that(s) of the metasurface(s) MS of another reflection device DR.

As illustrated in Figures 2 to 4, the main wall PP is intended to be installed in the closed space EF at a first distance d1 chosen from a

5 support wall PSS which partially delimits this closed space EF with interposition of the metasurface(s) MS at a second distance d2 chosen from the main wall PP and at a third distance d3 chosen from the support wall PSS. In addition, this main wall PP is made of a material which is not electrically insulating and which allows waves to pass (in reception as well as in reflection) without changing their waveform.

It will be understood that the main wall PP makes it possible to physically protect the metasurfaces MS (which are quite fragile), and therefore to make them much less, or not at all, exposed to shocks inside the closed space EF, while allowing waves to pass in both directions5 (incoming and outgoing) without disturbing them. Consequently, the material in which the main wall PP is made must be resistant and must have a dielectric coefficient compatible with the waves emitted which must be reflected by the metasurfaces MS located behind it and which it protects. For this purpose, it (PP) can, for example, be made of electrically non-insulating plastic material (but not of metal).

In addition, the second distance d2 separating the metasurface(s) MS from the main wall PP is intended to prevent the metasurface(s) MS from being in contact with the main wall PP, and in particular its (their) electrical part, so as not to disturb them and thus guarantee its (their) correct operation.

In addition, the third distance d3 separating the MS metasurface(s) from the PSS support wall is intended to prevent the MS metasurface(s) from being in contact with the PSS support wall. (frequently made of metal) to prevent the waves emitted by the metasurface(s) MS from being disturbed.

Thanks to the invention, it is therefore possible to very significantly increase the probability of identifying the objects O present in the closed space EF (with a metallic environment). It will be noted that when each metasurface MS is configurable, the detection device DD can comprise a computer CA, as illustrated without limitation in FIGS. 1 and 6.

Here, “configurable metasurface” means a metasurface that can

5 be configured by programming. For this purpose, it is possible to use, for example, so-called Huygens (or optical) metasurfaces. Thus, it is possible to use electrically or mechanically or optically or even thermally controllable metasurfaces. In the case of a mechanical control, the metasurface can, for example, comprise diodes associated with micro-electro-mechanical systems (or MEMS (“Micro ElectroMechanical System”)) which are themselves controlled by integrated circuits of type FPGA (“Field Programmable Gate Array”) or programmable microcontrollers or programmable chips with an integrated system (or PSoC (“Programmable System on a Chip)) or even possibly complex programmable logic devices (or (C)PLD (“( Complex) Programmable Logic Device”)).

The computer CA can be arranged to determine each first law of reflection and/or each second law of reflection as a function of the metallic environment and of the configuration of the closed space EF, then to determine each configuration of a configurable metasurface MS as a function of this first law of reflection and/or this second law of reflection, then to trigger the establishment by each configurable metasurface MS of each configuration concerning it and also possibly to adjust the power of the antenna AER via the L1 identification reader (if needed). This can in particular make it possible to adapt the detection device DD according to the closed space EF considered and/or the objects O present in the latter (EF) and/or the zones where the objects O are placed. the introduction of several different configurations (possibly successively) within the same closed space EF in order to further increase the probability of identifying the objects O.

For example, the first distance d1 can be between 20 mm and 40 mm. By way of illustrative example, the first distance d1 can be equal to 30 mm. Also for example, the second distance d2 can be greater than or equal to 1.5 mm. By way of illustrative example, the second distance d2 can be equal to 2.5 mm.

Also for example, the main wall PP can have a thickness

5 less than or equal to 2.5 mm at least next to the electrical part of the (each) metasurface MS. This prevents the main wall PP from disturbing incoming and outgoing waves. As an illustrative example, this thickness may be equal to 2 mm.

Also for example, and as illustrated without limitation in FIGS. 2 to 5, the reflection device DR can comprise a housing BD intended to be fixedly secured to the support wall PSS and in which the (each) metasurface MS is fixedly installed. In this case, the box BD comprises the main wall PP and side walls PL which are fixedly secured to the main wall PP (possibly perpendicular to its sides) and5 made of the same material as the latter (PP), and which surround the (each) metasurface MS. It will be understood that it is the height of the side walls PL of the box BD which defines the first distance d1. It will also be understood that the side walls PL are intended to reinforce the physical protection of the (each) metasurface MS installed in its housing BD, and can allow the attachment of the reflection device DR concerned to the support wall PSS concerned.

When the layer of air (with a thickness equal to d3) present between the metasurface(s) MS and the support wall PSS is not sufficient to ensure good insulation, the reflection device DR may comprise a piece 5 of insulation PI intended to be interposed between each metasurface MS and the support wall PSS, as illustrated without limitation in FIGS. 4 and 6. In this case, the insulation piece PI is made of a material which is insulating electrically. For example, this material can be a foam (possibly silicone, polyurethane, EPDM or polyethylene). But we0 could also use a resin or a thick polyester film.

It will be noted, as illustrated without limitation in FIG. 6, that the system S can comprise an external wall PE and an internal wall PI′ installed in front of this external wall PE at the first distance d1 chosen and participating in the delimitation of the closed space EF. This is the case, for example, when the system S comprises a box CS comprising the outer walls PE and the inner walls PI′ and possibly refrigerated. In this case, the outer wall PE defines a support wall PSS, and the inner wall PI' defines the main wall PP by at least

5 a reflection device DR. In other words, at least one element of a reflection device DR (namely the main wall PP) is a sub-part of the (possibly refrigerated) body CS. When the body is actually refrigerated CS, and it includes an insulation piece PI installed between its external walls PE and internal walls PI ', this insulation piece PI can also define another element of at least one reflection device DR (i.e. its own PI isolation piece). Each metastructure MS of a reflection device DR can then be installed between the insulation part PI of the body CS and the internal wall PI' (defining the main wall PP associated with this metastructure MS). 5 In the example illustrated without limitation in Figure 6, the inner wall PI 'of the box CS defines at the level of the roof T the main walls PP of two reflection devices DR, and the insulation part PI of the box CS defines the isolation parts PI of these two reflection devices DR.

It will also be noted, as illustrated without limitation in FIGS. 2 to 4.0, that the reflection device DR may comprise at least one spacer ES installed between the main wall PP and the metasurface(s) MS. In this case, the (each) spacer ES is made of an electrically non-insulating material, and has a thickness which is equal to the second distance d2 chosen. 5 For example, and as illustrated without limitation in FIGS. 2 and 4, the (each) spacer ES can be a protuberance forming an integral part of the main wall PP projecting on its face facing the (each) metastructure MS, and possibly rib-shaped (possibly straight). In this case, the (each) spacer ES is preferably placed on a part of each metasurface MS which is not its electrical part. As a variant, and as illustrated without limitation in FIG. 3, the (each) spacer ES can be a piece of added foam (and therefore installed between the main wall PP and the (each) metastructure MS of the reflection DR considered).

When the detection device DD comprises at least two reflection devices DR, as illustrated without limitation in FIGS. 1, 5 and 6, the latter (DR) can be connected in series, in particular when they are

5 coupled to the CA computer of the Ll identification reader. More precisely, it is their metasurfaces MS which are connected in series via first coupling parts PC1, such as electrical wires for example.

Furthermore, and as illustrated without limitation in FIG. 5, when a reflection device DR comprises several metasurfaces MS, the latter (MS) can be connected in series via second coupling parts PC2, such as electrical wires for example.

When the detection device DD comprises a computer CA and at least one reflection device DR comprising at least one programmable metasurface MS, this computer and this metasurface MS are preferably coupled by a third coupling part PC3, such as for example at least one wire electrical, as illustrated without limitation in Figure 5.

It will also be noted that the reflection devices DR of a system S do not necessarily have the same dimensions and arrangements. Thus, in example 0 illustrated without limitation in FIG. 5, the detection device DD comprises two identical reflection devices DR in the general shape of a square and another reflection device DR in the general shape of a rectangle. But these shapes can be the same or different, and the number of reflection devices DR of a detection device DD can take any value greater than or equal to one.

Furthermore, in the example illustrated without limitation in FIG. 5, the two identical reflection devices DR comprise four metasurfaces MS arranged with respect to each other in a square, and the other reflection device DR comprises six metasurfaces MS arranged one following the others while being aligned. But a reflection device DR can comprise any number of metasurfaces MS, provided that this number is greater than or equal to one. There is thus a great modularity, and it suffices to define main walls PP or boxes BD adapted to the needs of each reflection device DR. The BD boxes can then be coupled together on the right, left, top or bottom to make modules of different sizes. These modules of different sizes can therefore be adapted to any type of system S (for example (possibly utility) vehicles), for example to take into account some of their particularities, such as for example windows and/or seals.

Claims

1 . Reflection device (DR) for a detection device (DD), on the one hand, intended to equip a system (S) comprising a closed space (EF) to

5 metal environment and comprising at least one object (O) provided with an identification element (El) transmitter / receiver of waves, and, on the other hand, comprising an identification reader (Ll) exchanging messages with said identification element (El), via at least one antenna (AER) emitting/receiving waves and intended to be installed in said closed space (EF), in order to detect its presence, said reflection device (DR) comprising at least one metasurface (MS) configured so as to reflect waves coming from said antenna (AER) and intended for said identification element (El) and vice versa, characterized in that it further comprises a main wall (PP) intended to be installed in said closed space (EF)5 at a first chosen distance from a support wall (PSS) partially delimiting this closed space (EF) with the interposition of said metasurface (MS) at second and third chosen distances respectively from said main wall (PP) and support wall (PSS), made of an electrically non-insulating material and allowing said waves to pass without changing their waveform.

2. Reflection device according to claim 1, characterized in that it comprises an insulating part (PI) intended to be inserted between said metasurface (MS) and support wall (PSS) and made of an electrically insulating material. 5

3. Reflection device according to claim 1 or 2, characterized in that it comprises at least one spacer (ES) installed between said main wall (PP) and metasurface (MS) and made of an electrically non-insulating material, and having a thickness equal to said second chosen distance. 0

4. Reflection device according to one of claims 1 to 3, characterized in that said second distance is greater than or equal to 1.5 mm.

5. Reflection device according to one of claims 1 to 4, characterized in that said main wall (PP) has a thickness less than or equal to 2.5 mm at least next to an electnque part of said metasurface (MS).

6. Reflection device according to one of claims 1 to 5, characterized in that it comprises a housing (BD) intended to be fixedly secured to said support wall (PSS), in which said metasurface is fixedly installed.

5 (MS), and comprising said main wall (PP) and side walls (PL) fixedly secured to said main wall (PP), made of the same material as the latter (PP), and surrounding said metasurface (MS).

7. Detection device (DD) for a system (S) comprising a closed space (EF) with a metallic environment and comprising at least one object (O) provided with an identification element (El) emitter/receiver of waves , said detection device (DD) comprising an identification reader (Ll) exchanging messages with said identification element (El), via at least one antenna (AER) transmitting/receiving waves and intended to be installed in said closed space (EF), in order to detect its presence, characterized in that it further comprises at least one reflection device (DR) according to one of the preceding claims, intended to be fixedly secured to a support wall ( PSS) partially delimiting said closed space (EF).

8. System (S) comprising a closed space (EF) with a metallic environment and suitable for comprising at least one object (O) provided with an identification element (El) emitter/receiver of waves, characterized in that it further comprises at least one detection device (DD) according to claim 7.

9. System according to claim 8, characterized in that it constitutes a vehicle. 10. System according to claim 8 or 9, characterized in that it comprises i) an external wall (PE) defining a support wall (PSS), and ii) an internal wall (PI') installed at said first distance chosen from said external wall, defining a main wall (PP) of at least one reflection device (DR), and participating in the delimitation of said closed space (EF). 0