Wireless communication device for vertically stacked objects

Abstract

The present invention relates to a radio frequency communication device comprising: a base whose normal defines a vertical direction; a radio frequency communication reader; and a first arm whose major dimension extends in a first direction, wherein the first arm comprises at least two radio frequency antennas arranged along the first direction, the device comprising a system for rotating about an axis of rotation collinear with the vertical direction, each of the radio frequency antennas being connected to a port of the radio frequency communication reader, the at least two radio frequency antennas having polarization with respect to an electric field E, the radial component of which is less than one-fourth the norm of the electric field E, and the first arm being arranged radially outward of the axis of rotation.

Description

[Technical Field]

[0001] The present invention relates to the field of logistics management of connected or connectable assets, in particular assets of the tire casing type, whether or not the tire casing is mounted on a rim. [Background technology]

[0002] The development of electronic items in physical assets, such as tire casings, allows these assets to be combined and linked, stimulating the development of new services, for example, to optimize the use or identification of physical assets. The emergence of such digital capabilities leads to the rethinking of certain operations, particularly those related to the management of physical assets, in order to pool actions when physical assets are rarely used or when electronic items stored in the physical assets are available or rarely used. Operations for digitally identifying physical assets when stacked or for checking the legitimacy of stacked physical assets require that all communicating physical assets be readable to ensure the authenticity of the information exchanged without disrupting the formation of the physical assets. Changing the formation of a physical asset results in downtime for the physical asset, which increases transportation time and reduces productivity associated with the physical asset, such as the physical asset being unavailable during this step. Devices of these physical assets are capable of communication but are generally silent to conserve their own power or because of a lack of power.

[0003] It is therefore necessary to initiate communication of the communication devices of these physical assets, in particular to power them so that they can respond, or to check the suitability of the information they transmit with respect to the purpose of the stack of physical assets. All these operations take time, which negatively impacts the productivity of these physical assets equipped with communication devices. Generally, communication devices communicate on radio frequencies and comprise a transponder that is able to pick up a transmitted radio frequency signal, interpret it and perform an action in response to this signal, which may be, for example, the transmission of another radio frequency signal.

[0004] During logistics steps, physical assets are present in large quantities, and the means for handling these assets are often made of metal, which adversely affects the radio frequency communication of communication devices. To overcome this communication difficulty, it is necessary to position the physical asset so that the communication device faces away from the metal area. These operations require handling the physical asset on or off the conveyor line, which is time-consuming and has a negative impact on the productivity of the physical assets transported on the conveyor line. Another solution is to increase the power of the radio frequency communication, but this may cause unsolicited inquiries of some physical assets located near the target physical asset, which may lead to a high scrap rate of the physical asset, which also has a negative impact on reducing the production cost of the physical asset. Summary of the Invention [Problem to be solved by the invention]

[0005] The subject matter of the present invention presented below aims to improve the quality of radio frequency communication between multiple vertically stacked physical assets in order to reduce production costs associated with the use of the physical assets while ensuring robust and reliable radio frequency communication between the physical assets and external systems. All of this is done in relation to the flow of the stack of physical assets, and if expected, the stack remains unchanged. The first objective is to read all identifiers in the stack. The second objective is to be able to determine the order of identifiers in the stack, i.e., even the orientation of the objects in the stack, when their electronic devices are placed on one side or the other, depending on the orientation of the objects corresponding to the orientation of the stack. [Means for solving the problem]

[0006] The present invention relates to a radio frequency communication device suitable for communicating with radio frequency transponders having linearly polarized antennas associated with geometrically stable objects, the device being suitable for receiving at least two such objects arranged vertically adjacent to one another to form a stack circumscribing a circular cylinder, the polarization of the radio frequency transponders of the geometrically stable objects being mainly circumferential with respect to the axis of rotational symmetry of the cylinder circumscribing the stack of at least two objects, the device comprising: a base suitable for receiving a stack of objects, the normal of which defines a vertical direction; at least one radio frequency communication reader suitable for generating or reading electrical signals from a radio frequency antenna; at least one first arm having a major dimension extending along a first direction, the first direction preferably being collinear with the vertical direction; Equipped with The at least one first arm comprises at least two radio frequency antennas spaced apart from one another along the first direction. The device comprises a system for rotating a portion of a base adapted to receive a stack of vertically arranged objects about a rotation axis collinear with the vertical direction, adapted to rotate relative to at least one first arm; at least two radio frequency antennas each connected to a single port of at least one radio frequency communication reader; the at least two radio frequency antennas being elliptically polarized, preferably linearly polarized, and the electric field E has a radial component that is less than ¼ of the norm of the electric field E and a circumferential component that is less than ¼ of the norm of the electric field E relative to the rotation of the rotation system. The device is characterized in that the electric field E is 0.7 times the norm of the electric field E in a cylindrical coordinate system related to the rotation axis; two adjacent radio frequency antennas along the first direction form an antenna pair, each pair including radio frequency antennas located on either side of at least one first arm; the antennas located on the same side of the at least one first arm are separated by a distance d' along the first direction; and the arms are positioned radially outward with respect to the rotation axis of the rotation system and are suitable to be provided outside a cylinder circumscribing a stack of objects received by the device.

[0007] A physical asset may be equipped with a communication device within its structure or on its surface. If the physical asset is axisymmetric about an axis of rotational symmetry, even if the angular position of the communication device within the physical asset can be defined, the assets are stacked without being angularly positioned relative to each other so as not to waste cycle time for this purpose. The axisymmetric nature of the physical assets tends to make the azimuthal positioning of the physical assets relative to each other unimportant.

[0008] In this case, performing an angular scan between the stacked physical assets and the first arm using a rotation system ensures that all transponders of the physical assets are read. The rotation system can rotate the stacked physical assets alone or the first arm alone, or rotate the two physical assets differently, for example in different rotation directions or at different rotation speeds. If each geographical area of ​​the physical assets is observed for the same period of time during the reading phase, all radio frequency transponder readings related to all stacked physical assets are performed evenly.

[0009] Inevitably, to identify the vertical position of a radio frequency transponder, at least two radio frequency antennas vertically spaced apart from each other are required to communicate with different regions of the stack. Therefore, only radio frequency transponders present in that region of the stack communicate with the radio frequency antenna associated with that region. To divide the stack of physical assets into various regions, the antennas are spaced apart from each other along the direction of the stack. This method allows all antennas to initiate radio frequency transmission and reception. By having multiple radio frequency antennas and interleaving the antennas that communicate with the radio frequency transponders of the physical assets, it is possible to read all of the transponders and establish the transponders' relative vertical positions. Connecting each radio frequency antenna to a single port of at least one radio frequency communication reader allows communication between the radio frequency antenna of the communication device and the radio frequency transponders of the physical assets to be non-sequential, thereby saving communication time between the communication device and the stack of objects. Finally, adjacent radio frequency antennas are located on opposite sides of the first arm, ensuring that the radiation patterns of the two antennas overlap little or not at all. All that is required is that two antennas located on the same side of the first arm are spaced apart from each other by a distance d' along the first direction so that their radiation patterns do not interfere with each other. Thus, the communication area of ​​the stack can be created using multiple antennas positioned at optional different heights, preferably midway along the height of the distance d'.

[0010] This second function determines a satisfactory order for the physical assets of the stack.

[0011] The physical asset's radio frequency transponder has a linearly polarized antenna that is primarily oriented circumferentially with respect to the axis of rotational symmetry of the cylinder circumscribing the stack. That is, the antenna's electric field E has a radial component whose amplitude is less than one-quarter of the norm of the electric field E in a cylindrical coordinate system related to the rotation axis of the rotating system. To ensure effective communication between the physical asset's radio frequency transponder and the device's radio frequency antenna, the polarization axis of the device's radio frequency antenna must be collinear with the polarization axis of the physical asset's radio frequency transponder. To this end, the component of the electric field E of each radio frequency antenna is constrained relative to the rotation axis of the rotating system, so that the polarization axis of the radio frequency antenna is primarily oriented circumferentially with respect to the stack's rotation axis. The specific characteristics of the components of the electric field generated by the radio frequency antenna of the device according to the present invention in the cylindrical coordinate system ensure that the circumferential component of the electric field E is equal to at least 0.7 times the norm of the electric field E generated by the transmitting radio frequency antenna. Furthermore, the radial component of the electric field E is the component with the smallest amplitude. In this way, the polarization axis of the radio frequency antenna of the device is substantially collinear with the polarization axis of the transponder of the physical asset, ensuring high-quality radio frequency communication. Therefore, the communication energy of the device is optimized to communicate with the transponder of the physical asset due to the collinearity between the axis of the linear antenna and the electric field E, which ensures improved communication between the antennas, allowing for faster relative rotation speeds between the stack of physical assets and the arms of the antenna while maintaining high-quality communication. For this purpose, the radio frequency antenna of the device is elliptically polarized, preferably linearly polarized, provided that the circumferential component is maximized. Antenna polarization is an adaptation to the electric field to optimize the energy exchanged between the antenna and the electric field, and should not be confused with antenna directivity, which allows for the concentration of energy in a region of space around the antenna.

[0012] Advantageously, the communication device comprises a system for positioning the at least one first arm relative to an axis of rotation of a rotation system defining the trajectory of the at least one first arm.

[0013] Thus, the communication device can accommodate any diameter of a cylinder circumscribing the stacked physical assets while ensuring an acceptable distance between the radio frequency transponders of the physical assets rotating about the rotation axis of the rotation system and the radio frequency antenna of the communication device. However, the communication device can also accommodate any angle of the cone of the stack of physical assets by using an inclination between the first direction of the arm and the vertical direction of the base, while ensuring a similar distance between the radio frequency transponders of the physical assets forming the cone and the radio frequency antenna of the communication device. The trajectory followed by the arm to be positioned relative to the stack can be, for example, a translation, a rotation about an axis, or a combination of a translation and a rotation about an axis.

[0014] Preferably, the system for positioning the at least one first arm comprises a system for guiding the translation of the at least one first arm along a translation direction, which translation direction preferably intersects the rotation axis of the rotation system.

[0015] The most basic movement of the first arm is translation along a single direction, preferably intersecting the rotation axis of the rotation system, which ensures that the polarization axis of the device's radio frequency antenna remains approximately circumferential with respect to the rotation axis of the rotation system.

[0016] According to another embodiment, the device comprises an actuation system suitable for moving the at least one first arm relative to a trajectory imposed by the positioning system.

[0017] This allows the positioning of the first arm relative to the stack of physical assets to be automated without human intervention.

[0018] Advantageously, the communication device comprises a limiter, preferably including a sensor, suitable for stopping the movement of the first arm along the trajectory imposed by the positioning system when a threshold value is reached.

[0019] For the purpose of automating the device and to avoid damaging the stacked physical assets, the device comprises a limiter suitable for stopping the movement of the first arm on the trajectory imposed by the positioning system. The limiter, which may comprise a sensor or may comprise an open loop, numerically evaluates the proximity of the first arm to the stacked physical assets. The sensor may be a load cell measuring the contact force between the arm and the physical asset, or a proximity sensor evaluating the distance between the arm and the outer surface of the vertical stack. However, in the case of an open loop, pneumatic, hydraulic, electric, or magnetic setpoints may be used.

[0020] According to one embodiment, the communication device comprises a system for centering with respect to the axis of rotation of the rotation system.

[0021] Preferably, the centering system comprises at least one vertical second arm radially coupled to the at least one first arm relative to the rotation axis of the rotation system.

[0022] The stack of physical assets and / or the first arm are preferably positioned relative to the rotation axis of the rotating system. Therefore, the first arm is positioned relative to the stack at a predetermined angular position relative to the rotation axis, which allows for high-speed angular scanning of the stack of physical assets or the first arm. This centering system can be composed of a series of vertical arms, including the first arm in particular, whose concentric motion is uniform relative to the rotation axis. Therefore, the concentric motion of the arms tends to position the stack of physical assets so that the axis of rotational symmetry of a cylinder circumscribing the stack coincides with the rotation axis of the rotating system. To achieve this, the second arm only needs to extend vertically, at least on physical assets located at one end of the stack. Generally, physical assets located near the base have the largest radial dimension to ensure the stability of the vertical stack; in this case, the second arm is located near the base. This arm system can move the stack of physical assets above the base.

[0023] Preferably, the rotation system is integrated into the base of the communication device.

[0024] This is a compact embodiment in which a rotation system emerges from the base to rotate, for example, by lifting the stack of physical assets and / or the first arm from the base. Once rotation is complete, the rotation system disappears below the base to allow handling of the stack of physical assets. One alternative is to place the rotation system vertically above the stack, but this would require specific components that are coupled to the stack but do not form part of it.

[0025] According to one particular embodiment, the communication device comprises displacement means integrated into the base, suitable for defining a trajectory passing through the axis of rotation of the rotation system and for displacing along the trajectory a stack of physical assets received by the device.

[0026] These displacement means make it possible to handle the stack of physical assets on the base. They can be, for example, roller belts. Furthermore, as the track intersects the axis of rotation, the displacement means make it possible to center the stack of physical assets with respect to the axis of rotation of the rotation system, facilitating the movement of the stack along the defined track.

[0027] Advantageously, the at least one first arm comprises a reflecting element located radially outside the at least one first arm relative to the axis of rotation of the rotation system.

[0028] This reflective element, i.e., an element that reflects electromagnetic waves, allows for interrogation of radio frequency transponders of physical assets located within the stack rather than outside the stack, thereby minimizing the risk of accidentally interrogating radio frequency transponders of physical assets located in another stack or associated with the environment in which the communications device is located.

[0029] Very advantageously, the reflective element is positioned radially outward from the at least two radio frequency antennas at a distance e, which distance e is preferably less than 0.5 times the wavelength associated with the frequency of the device, where the distance between the two components refers to the perpendicular projection of the reflective element.

[0030] To benefit from the influx of radiated power towards the stack, the reflective element must be appropriately positioned relative to the radio frequency antenna of the communication device, which is the source of the electromagnetic waves. By observing the mentioned proximity between the reflective element and the radio frequency antenna, the communication capability of the communication device is substantially increased by increasing the radiated power sent towards the stack of physical assets. In the case of passive radio frequency transponders, such as RFID (radio frequency identification) tags, the more power sent, the more effective the radio frequency communication.

[0031] According to one particular embodiment, the communication device comprises at least one other first arm positioned at the same radial position but at a different azimuthal position relative to the at least one first arm relative to the rotation axis of the rotation system, the first arms preferably being evenly distributed around the rotation axis.

[0032] Having multiple first arms increases the number of communication antennas. Positioning different arms at different azimuthal positions but the same radial position relative to the axis of rotation of the rotating system allows for interrogating all radio frequency transponders of a stack of physical assets with a minimum number of rotations of the stack of physical assets, or for interrogating the radio frequency transponders of a stack multiple times with a minimum number of rotations of the stack. Preferably, when the first arms are evenly distributed around the stack, the angular portion separating two adjacent first arms is sufficient to provide reliable, effective, and fast interrogation of the entire stack of physical assets.

[0033] According to another specific embodiment, each of the at least one other first arm comprises at least two radio frequency antennas, the two radio frequency antennas of each of the at least one other first arm being located at a different height relative to the height of the at least two radio frequency antennas of the at least one first arm.

[0034] In this configuration, an increase in the read speed of the stack's radio frequency transponders is not systematically sought, but an increase in spatial discrimination, particularly vertical discrimination, between the stack's radio frequency transponders is sought. The pitch between the radio frequency antennas increases vertically, due to the azimuthally distributed placement of the antennas around the stack, without managing radio frequency interference between antennas that are vertically close together.

[0035] According to another particular embodiment, the communication device comprises two first arms located diametrically opposite each other relative to the axis of rotation of the rotation system.

[0036] This is a balanced configuration in terms of the number of first arms, making it possible to perform one half rotation of the stack to interrogate all of the radio frequency transponders in the stack with sufficient differentiation, for example vertically relative to the tire casing.

[0037] Preferably, each radio frequency antenna defines a communication area characterized by a gain and a beam angle αi, which, depending on the power supplied, defines a maximum distance Di from the communication area, and the distance d′ along the first direction separating two radio frequency antennas located on the same side of the at least one first arm is less than a threshold A defined by the following formula: [Formula 1] JPEG2025528043000002.jpg1343

[0038] This ensures that no electromagnetic radiation white spots appear between two antennas that are adjacent along the first direction and on the same side of the first arm with respect to the stack. One possible means for ensuring the geographic coverage of the antennas is to adjust the power supplied to the radio frequency antennas within the valid standards. Providing enough radio frequency antennas on the first arm to cover a height that exceeds the maximum height of the stack of physical assets ensures that the communication device covers the interrogation and reading of every stack of physical assets. This ensures that all radio frequency transponders of the physical assets in the stack are interrogated and listened to by the communication device.

[0039] Preferably, the at least two radio frequency antennas are selected from the group consisting of a dipole antenna, a slot antenna, a loop antenna, and a patch antenna.

[0040] The first two antennas, the dipole and the slot, are linearly polarized antennas, with the axis of the dipole or the axis of the slot defining the polarization axis of the antenna. The next two, the loop and the patch, are circularly or elliptically polarized antennas. The plane of the antenna will be positioned in a plane whose normal is substantially radial in a cylindrical coordinate system related to the axis of rotation of the rotating system. Optionally, the shape of the antenna can be determined to favor one of the two directions defining the plane of the antenna, thereby achieving an elliptically polarized antenna that allows for the circumferential direction of a cylindrical coordinate system related to the axis of rotation of the rotating system to be preferred over the radial direction.

[0041] The present invention also relates to the use of the communication device with stacked objects selected from the group consisting of tire casings, wheels, wheel valves such as TPMS (Tire Pressure Monitoring System) valves, and elastomeric elements of mounting assemblies.

[0042] These are physical assets that can be stacked to define, for example, a mounting assembly for a passenger vehicle. The tire casing can be equipped with an RFID (Radio Frequency Identification) tag located on the sidewall of the tire and circumferentially oriented relative to the natural axis of rotation of the tire casing. The valve of the wheel and mounting assembly can also be equipped with a radio frequency transponder with a communication antenna circumferentially oriented relative to the natural axis of rotation of the wheel (which in the case of the mounting assembly is coincident with the axis of rotation of the tire casing).

[0043] The invention also relates to a conveyor line suitable for transporting stacked objects along a given path, the conveyor line comprising a communication device suitable for communicating with radio frequency transponders associated with these objects.

[0044] Preferably, the radio frequency communication device is positioned between two conveyors, the first conveyor positioned upstream of a given path being equipped with a centering system suitable for positioning the stack of objects relative to the width of the radio frequency communication device.

[0045] In the field of logistics, incorporating a radio frequency communication device along a conveyor line allows for monitoring of stacks of objects while transporting them with minimal immobilization, ensuring competitive production costs. In the event of a non-conforming stack, incorporating the radio frequency communication device between two conveyors in a conveyor line also allows for the non-conforming stack of objects to be removed from the flow. Product identification and sequencing, and optionally, their orientation, are optimized as a result. Centering the stack transversely to the track defined by the radio frequency communication device ensures that the stack is pre-positioned relative to the communication device. Consequently, if the communication device includes integrated displacement and centering means, centering the stack relative to the track minimizes stack centering perpendicular to the track of the displacement means of the communication device. Consequently, the centering means of the communication device aligns the axis of rotation of a cylinder circumscribing the stack of physical assets with the axis of rotation of a rotation system housed in the communication device. Therefore, the size of the centering system is minimized, which reduces costs.

[0046] The invention will be better understood from a reading of the following description, given purely by way of non-limiting example, with reference to the accompanying drawings in which the same reference numbers represent the same elements in all cases, in which: [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a perspective view of a first radio frequency communication device according to the present invention; [Figure 2] FIG. 2 is a perspective view of a second radio frequency communication device according to the present invention. [Figure 3]1 is a radiation pattern of a radio frequency antenna. [Figure 4] 1 illustrates a stack of physical assets comprising tire casings containing RFID (Radio Frequency Identification) tags. [Figure 5] FIG. 1 is a perspective view of a conveyor line equipped with radio frequency communication devices. DETAILED DESCRIPTION OF THE INVENTION

[0048] 1 shows a first radio frequency communication device 1. The device comprises a base 2 defining a vertical direction 21 along a normal to its outer surface, against which the other elements of the radio frequency device 1 are located and which corresponds to the surface in contact with the stack of physical assets. The device 1 also comprises a first arm 4, the main direction of which defines a first direction 22. This first direction 22 is collinear with the vertical direction 21.

[0049] For rotating the stack of physical assets, the device 1 comprises a system 5, here represented by a cross integrated into the base 2 of the device 1 and rotating about an axis of rotation 31. This cross 5 also translates in the vertical direction 21 so as to be below or above the fixed outer surface of the base 2, depending on the phase of communication between the device 1 and the stack of physical assets. In this way, the stack of physical assets can be immobilized or translated relative to the fixed part of the base 2 of the device 1.

[0050] The first arm 4 is provided with radio frequency antennas divided into two groups located on both sides thereof. The first group includes antennas 10a, 10b, and 10c, and the second group includes radio frequency antennas 10d and 10e. These radio frequency antennas 10a, 10b, 10c, 10d, and 10e are galvanically connected to the radio frequency reader 3. The radio frequency reader 3 transmits and receives radio frequency signals to and from the radio frequency antennas. The radio frequency antennas 10a, 10b, 10c, 10d, and 10e are physically connected to the radio frequency reader 3 using ports on the radio frequency reader 3, with each antenna connected to a single port. The radio frequency antennas 10a, 10b, 10c, 10d, and 10e of each group are paired and separated from each other by a distance d' so that the height of the stack of physical assets is covered by the radio frequency radiation of the radio frequency antenna groups. Conversely, this configuration allows for improved discrimination between the radio frequency transponders of the stack objects along the vertical direction 21, due to the different antenna heights of the two groups. In this optimized configuration, the first arm 4 comprises a reflective element 15 located radially outward of its radio frequency antennas 10a, 10b, 10c, 10d, and 10e. The distance e between the antennas 10a, 10b, 10c, 10d, and 10e and the reflective element is less than half a wavelength associated with the communication frequency of the device 1. This reflective element 15 prevents radio frequency radiation radially outward of the reflective element 15 relative to the rotation axis 31. Furthermore, the distance e between the reflective element 15 and the radio frequency antennas 10a, 10b, 10c, 10d, and 10e ensures improved radio frequency power radiated towards the stack of physical assets. The antenna of the device is elliptically polarized, preferably linearly polarized, so that the main component of the transmitted field is propagated in the circumferential direction in a cylindrical coordinate system related to the rotation axis 31 of the rotation system 5 .

[0051] Here, the stack of physical assets is translated relative to the device 1 by means 12 for displacing it. These displacement means 12, integrated into the base 2, here consist of a series of rollers parallel to one another. Each roller rotates about an axis, which here are collinear. A track 121 for the stack of physical assets is thus formed using the rollers. Here, this track 121 passes through the rotation axis 31 of the rotation system 5. These displacement means 12 facilitate guiding the stack of physical assets on the base 2 so as to position the stack of physical assets relative to the rotation axis 31 of the rotation system 5 of the device 1. In this case, the rotation system 5 rises above the outer surface of the base 2 and carries the stack of physical assets, thereby pulling them away from the outer surface of the base 2. The rotation system 5 then begins to rotate about the rotation axis 31 to rotate the stack of physical assets.

[0052] In this configuration, the first arm 4 is translationally guided by a positioning system 6. Here, this positioning system 6 comprises a translational guide system 7 consisting of a groove provided in the outer surface of the base 2. This groove 7 defines a translational direction 71 passing through the rotation axis 31 of the rotation system 5. This allows the first arm 4 to approach the stack of physical assets regardless of the radial dimension of the stack of physical assets.

[0053] The first arm 4 is driven by an actuation system comprising an electrical, pneumatic or hydraulic power source and ensuring automatic translation of the first arm 4 along the direction 71. Likewise, in order to automate the positioning of the first arm 4, the device 1 here comprises a limiter that controls the displacement of the first arm 4 along the trajectory 7 depending on the proximity of the first arm 4 to the stack of physical assets. This limiter therefore comprises a sensor that determines the distance between the sensor and the stack of physical assets and is adapted to stop the movement of the first arm 4 according to measurements provided by this sensor relative to a threshold value that represents a collision between the first arm 4 and the stack of physical assets. This sensor is an electromagnetic or optical proximity or contact sensor.

[0054] The translation guidance system 7 is capable of uniquely positioning the radio frequency antennas 10a, 10b, 10c, 10d, and 10e of the first arm 4 such that the polarization directions of these antennas 10a, 10b, 10c, 10d, and 10e are primarily circumferential with respect to the rotation axis 31 of the rotation system 5. Here, the radio frequency antennas 10a, 10b, 10c, 10d, and 10e are elliptically polarized loop antennas whose primary polarization direction extends circumferentially with respect to the rotation axis 31.

[0055] Finally, the device 1 here comprises a centering system 9, which allows for the proper positioning of the stack of physical assets relative to the rotation system 5, more precisely, for the axis of rotational symmetry of the cylinder circumscribing the stack of physical assets to be coaxial with the rotation axis 31 of the rotation system 5. This improves the dynamic stability of the stack of physical assets by balancing the centrifugal forces acting on the stack of physical assets over the entire circumference of the stack of physical assets, especially during high-speed rotation of the stack of physical assets. The centering system 9 here comprises a first arm 4 and a second arm 11. The two arms are coupled to each other to ensure opposite translations, such that the distance between each arm and the rotation axis 31 of the rotation system is the same. For this purpose, the second arm 11 translates along the same direction 71 as the first arm 4, thanks to a groove made in the outer surface of the base 2.

[0056] Furthermore, this centering of the stack of physical assets ensures that the distance between the first arm 4 and every material point of the stack of physical assets located at the height H of the stack along the vertical direction 21 is the same. As a result, radio frequency communication between the radio frequency transponders of the physical assets and the radio frequency antennas 10a, 10b, 10c, 10d, and 10e of the first arm 4 is uniform.

[0057] 2 shows a second radio frequency communication device 1 according to the invention. This device 1 also comprises a base 2 suitable for holding a stack of physical assets. The device 1 also comprises a first arm 4 comprising radio frequency antennas 10a, 10b, 10c, 10d, 10e and 10f, which are connected to a radio frequency reader 3 by means of connection ports. However, here the first arm 4 extends primarily along a first direction 22 that is not necessarily collinear with a vertical direction 21 defined by the outer surface of the base 2, which is the surface for receiving the stack of physical assets.

[0058] The first arm 4 is equipped with radio frequency antennas divided into two groups located on both sides of the arm. The first group includes antennas 10a, 10b, and 10c, and the second group includes radio frequency antennas 10d, 10e, and 10f. These radio frequency antennas 10a, 10b, 10c, 10d, 10e, and 10f are galvanically connected to the radio frequency reader 3. The radio frequency reader 3 transmits and receives radio frequency signals to and from the radio frequency antennas. The radio frequency antennas 10a, 10b, 10c, 10d, 10e, and 10f are physically connected to the radio frequency reader 3 using ports on the radio frequency reader 3, with each antenna connected to a single port. The radio frequency antennas 10a, 10b, 10c, and 10d, 10e, and 10f of each group are paired and separated by a distance d' so that the height of the stack of physical assets is covered by the radio frequency radiation of the radio frequency antenna groups. Conversely, this configuration allows for improved discrimination between the radio frequency transponders of stack objects along the vertical direction 21, due to the different antenna heights of the two groups.

[0059] The device 1 comprises a system 5 for rotating about an axis of rotation 31. However, the rotation system 5 drives the rotation of the first arm 4 instead of rotating the stack of physical assets as in Figure 1 .

[0060] The device 1 also comprises a system 6 for positioning the first arm 4 relative to the rotation axis 31 of the rotation system 5. The positioning system 6 comprises a translation guiding system 7 by means of a groove, which defines a trajectory of the first arm 4 along a translation direction 71, which intersects with the rotation axis 31 of the rotation system 5. The positioning system 6 also comprises a system for rotating the first arm 4 relative to the rotation axis 41 in order to define a first direction 22 of the first arm 4.

[0061] The translation guidance system 7 can uniquely position the radio frequency antennas 10a, 10b, 10c, 10d, 10e, and 10f on the first arm 4 such that the polarization directions of these antennas 10a, 10b, 10c, 10d, 10e, and 10f are primarily circumferential with respect to the rotation axis 31 of the rotation system 5. Here, the radio frequency antennas 10a, 10b, 10c, 10d, 10e, and 10f are linearly polarized half-wave dipole antennas whose primary polarization direction extends circumferentially with respect to the rotation axis 31.

[0062] The movement of the first arm 4 by the positioning system 6 is automated by an actuation system that controls both the rotation of the first arm 4 about the axis of rotation 41 and the translation of the first arm 4 along the translation direction 71 in order to ensure the proximity of the first arm 4 to the stack of physical assets. Furthermore, the device 1 comprises a limiter that controls the drive of the first arm 4. This limiter therefore comprises a sensor that determines the distance between the sensor and the stack of physical assets and is adapted to stop the movement of the first arm 4 according to measurements provided by this sensor relative to a threshold value that represents a collision between the first arm 4 and the stack of physical assets. This sensor is an electromagnetic or optical proximity or contact sensor.

[0063] Here, the stack of physical assets is translated relative to the device 1 by means 12 for displacing it. These displacement means 12, integrated into the base 2, consist here of a series of rollers parallel to one another, which may also be slider beds. Each roller rotates about an axis, which are here collinear. A track 121 for the stack of physical assets is thus formed by means of the rollers.

[0064] Here, this track 121 passes through the axis of rotation 31 of the rotation system 5. These displacement means 12 facilitate guiding the stack of physical assets on the base 2 so as to position the stack of physical assets relative to the axis of rotation 31 of the rotation system 5 of the device 1.

[0065] Finally, the device 1 here comprises a centering system 9, which allows the stack of physical assets to be properly positioned relative to the rotating system 5, more precisely, to align the axis of rotational symmetry of a cylinder circumscribing the stack of physical assets with the axis of rotation 31 of the rotating system 5. The centering system 9 here comprises four second arms evenly spaced on either side of the means 12 for displacing the stack of physical assets. The four second arms are coupled to one another to ensure a clamping action around the axis of rotation 31 of the rotating system 5, with the same distance between each arm and the axis of rotation 31 of the rotating system 5. For this purpose, the second arms here translate along two translation directions, thanks to grooves made in the outer surface of the base 2. These two translation directions intersect at the axis of rotation 31 of the rotating system 5.

[0066] Furthermore, this centering of the stack of physical assets ensures that the distance between the first arm 4 and every mass point of the stack of physical assets located at the height H of the stack along the vertical direction 21 is the same. As a result, radio frequency communication between the radio frequency transponders of the physical assets and the radio frequency antennas 10a, 10b, 10c, 10d, 10e, and 10f of the first arm 4 is uniform.

[0067] 3 shows a main radio frequency radiation lobe 51 for the radio frequency antenna 10a of the first arm of a radio frequency communication device in the plane defined by the polarization axis 50 of the radio frequency antenna 10a and the first direction 22 of the first arm, where the radio frequency antenna 10a is a half-wave dipole antenna.

[0068] From the power supplied to the antenna, the antenna radiates in all directions, such that the isopower curves represent closed contours at both ends of the antenna 10a. Figure 3 shows the radio frequency radiation isopower curves 51. It is then possible to determine the distance D and beam angle α associated with this radio frequency antenna, thereby characterizing the effective communication area of ​​this antenna 10a. Here, the depiction is limited to a subspace because the communication area of ​​a dipole antenna is axially symmetric about the antenna's polarization axis 50.

[0069] Therefore, an effective distance D' corresponding to the product of cos α and the distance D of the isopower curve 51 is determined, which determines the distance at which at least half of the radio frequency power is exchanged between the radio frequency antenna 10a and a particle point in space located at the distance D'.

[0070] Since the radio frequency antennas are positioned along the first direction of the first arm in groups, the spacing between two adjacent antennas along the first direction of each group, i.e., antennas located on the same side of the first arm, must be smaller than the sum of the distances D' associated with the radio frequency antennas.

[0071] 4 shows a stack 200 of physical assets, where the physical assets are four mounting assemblies, of which only tire casings 210a, 210b, 210c, and 210d are shown. The casings are stacked on top of each other along a direction defined by axis 202. Thus, stack 200 is inscribed in a right circular cylinder having axis 202, the diameter of which corresponds to the outermost diameter of tire casings 210a, 210b, 210c, and 210d.

[0072] Here, stack 200 is placed on base 201, which facilitates displacement of stack 200. Base 201 is provided with displacement means, such as casters not shown in FIG. 4, on a surface opposite to the surface that contacts stack 200. Thus, stack 200 can be manually positioned relative to the radio frequency communication device, and in particular, relative to the first arm and the rotation axis of the rotation system of the radio frequency communication device. In this case, the radio frequency communication device does not necessarily require means for displacing the stack of physical assets.

[0073] Each tire casing 210a, 210b, 201c, and 210d includes a radio frequency transponder 211a, 211b, 211c, 211d, which in this case is an RFID tag consisting of an electronic chip connected to a linearly polarized, half-wave dipole radio frequency antenna that extends along its major dimension circumferentially relative to axis 202.

[0074] 5 shows a conveyor line 100 for stacked physical assets equipped with radio frequency communication devices 1, where the devices 1 correspond to those shown in FIG.

[0075] The conveyor line 100 defines a path 110 along which a stack of physical assets moves from a start point to an end point. Here, the path 110 extends across three elements of the conveyor line 100: a first conveyor 101a located upstream of the path 110, a second conveyor 101b located downstream of the path 110, and a radio frequency communication device 1 located between the two conveyors 101a, 101b. Here, the two conveyors 101a and 101b are equipped with drive rollers whose main directions are perpendicular to the path 110. The first conveyor 101a is equipped with a centering system 102 for guiding the stack of physical assets towards the center of the width of the conveyor 101a, thereby preparing the stack of physical assets to pass in front of the radio frequency communication device 1. Since the radio frequency communication device 1 is located in the width center of the first conveyor 101 a, the centering system here comprises two lane narrowing elements 102 that are symmetrical with respect to the path 110 . [Explanation of symbols]

[0076] 1. First radio frequency communication device 2 base 3 Radio Frequency Reader 4. First Arm 5. Stack Rotation System 6 Positioning System 7 Translational Guidance System 9 Centering System 10a, b, c Radio frequency antennas (first group) 10d,e Radio frequency antennas (second group) 11 Second Arm 12 Means for displacing the stack 15 Reflective Elements 21 Vertical direction 22 First Direction 31 Rotation axis 71 Translation direction 121 Orbit

Claims

1. A radio frequency communication device (1) suitable for communicating with a radio frequency transponder having a linearly polarized antenna associated with a geometrically stable object, wherein the device (1) is suitable for receiving at least two of the objects arranged adjacent to each other and vertically to form a stack circumscribing a cylinder, wherein the polarization of the radio frequency transponder of the geometrically stable object is mainly oriented circumferentially with respect to the rotational symmetry axis of the cylinder circumscribing the stack of the at least two objects, and the device, Suitable for receiving a stack of the aforementioned objects, it has a base (2) whose normal defines the vertical direction (21), A radio frequency communication reader (3) suitable for generating or reading electrical signals with a radio frequency antenna, A first arm (4) whose main dimension extends along a first direction (22), wherein the first direction (22) is preferably collinear with the vertical direction (21), Equipped with, The at least one first arm (4) comprises at least two radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) spaced apart from each other along the first direction (22), A system (5) for rotating a portion of the base suitable for receiving a stack of objects arranged vertically around a rotation axis (31) collinear with the vertical direction (21), suitable for rotating a portion of the base suitable for rotating a portion of the base around the at least one first arm (4), each of the at least two radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) is connected to a single port of at least one radio frequency communication reader (3), the at least two radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) are elliptically polarized, preferably linearly polarized, and the electric field E has a radial component less than 1 / 4 of the norm of the electric field E, and a circumferential component of the electric field E in a cylindrical coordinate system relating to the rotation axis (31) of the rotation system (5) A radio frequency communication device (1) characterized in that the norm is 0.7 times, two adjacent radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) along the first direction (22) form a pair of antennas, each pair including the radio frequency antennas located on both sides of the at least one first arm (4), the radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) located on the same side of the at least one first arm (4) are separated by a distance d' along the first direction (22), and the at least one first arm (4) is positioned radially outward with respect to the rotation axis (31) of the rotating system (5) and is suitable for being provided outside the cylinder that circumscribes the stack of objects received by the device.

2. The radio frequency communication device (1) according to claim 1, further comprising a system (6) for positioning the at least one first arm (4) with respect to the rotation axis (31) of the rotation system (5) that defines the trajectory of the at least one first arm (4).

3. The radio frequency communication device (1) according to claim 2, wherein the system (6) for positioning the at least one first arm (4) comprises a system (7) for guiding the translation of the at least one first arm (4) along a translation direction (71), the translation direction (71) intersects with the rotation axis (31) of the rotation system (5).

4. The radio frequency communication device (1) according to any one of claims 1 to 3, further comprising a system (9) for centering the rotating system (5) with respect to the rotating shaft (31).

5. The radio frequency communication device (1) according to claim 4, wherein the centering system (9) comprises at least one vertical second arm (11) radially coupled to the at least one first arm (4) with respect to the rotation axis (31) of the rotation system (5).

6. The radio frequency communication device (1) according to claim 1, wherein the rotating system (5) is incorporated into the base (2) of the communication device (1).

7. The radio frequency communication device (1) according to claim 1, comprising a displacement means (12) incorporated in the base (2) that defines a trajectory (121) passing through the rotation axis (31) of the rotation system (5) and is suitable for displacing a stack of physical assets received by the device along the trajectory (121).

8. The radio frequency communication device (1) according to claim 1, wherein the at least one first arm (4) comprises a reflecting element (15) located radially outward of the at least one first arm (4) with respect to the rotation axis (31) of the rotation system (5).

9. The radio frequency communication device (1) according to claim 8, wherein the reflective element (15) is positioned radially outward at a distance e from the at least two radio frequency antennas (10a, 10b, 10c, 10d, 10e), and the distance e is preferably less than 0.5 times the wavelength related to the communication frequency of the device (1).

10. The radio frequency communication device (1) according to claim 1, wherein the radio frequency communication device (1) comprises at least one other first arm positioned at a different azimuth angle position at the same radial position with respect to the at least one first arm (4) with respect to the rotation axis (31) of the rotation system (5), and preferably the first arms are evenly distributed around the rotation axis (31).

11. The radio frequency communication device (1) according to claim 10, wherein each of the at least one other first arm comprises at least two radio frequency antennas, and the two radio frequency antennas of each of the at least one other first arm are positioned at different heights from the heights of the at least two radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) of the at least one first arm (4).

12. The radio frequency communication device (1) according to claim 10, comprising two first arms (4) positioned diametrically opposite to each other with respect to the rotation axis (31) of the rotation system (5).

13. Each of the radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) defines a communication area (51) according to the power supplied, and the communication area (51) is characterized by a gain and beam angle αi that define the maximum distance Di from the communication area (51), and the distance d' along the first direction (22) separating the two radio frequency antennas (10a, 10b, 10c, 10d, 10e, 10f) located on the same side of the at least one first arm (4) is less than the threshold A defined by the following equation: [Equation 1] The radio frequency communication device (1) according to claim 1.

14. Use of the radio frequency communication device (1) according to claim 1, with an object selected from the group consisting of a tire casing, a wheel, a wheel valve such as a TPMS valve, and an elastomer element of a mounting assembly.

15. A conveyor line (100) suitable for transporting stacked objects along a given path (110), comprising the radio frequency communication device (1) described in claim 1.

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