Radiofrequency reading system on board a transport vehicle

Abstract

The invention relates to a vehicle (2) equipped with a mobile assembly (1) comprising a pneumatic tyre (12) rotated about an axis (102), the mobile assembly (1) being equipped with a radiofrequency transponder (100) and a reading system (3) comprising: - a generator coupled with a demodulator (31) of electrical signals; - a cable (32) galvanically connected to the generator (31), attached to the transport means (2) comprising a radiating part (342), characterised in that the projection R on a cylinder (104), of axis of revolution (102), circumscribed on the pneumatic tyre (12) of the radiating part is less than 1 metre, in that the radiating part (342) comprises a meander (500), the curvilinear length of the meander (500) is between 0.9 and 1.1 times the half-wavelength L0 associated with the communication frequency, the distance "P" between the two ends of the meander (500) is less than a quarter wavelength.

Description

DESCRIPTION TITLE: RADIO FREQUENCY READING SYSTEM ON BOARD A TRANSPORT VEHICLE Field of invention

[0001] The present invention relates to a system for reading radiofrequency transponders on board a transport vehicle. The radiofrequency transponders are mainly linked to the moving assemblies of the transport vehicle. Technological background

[0002] The recent development of connected objects requires equipping them with radiofrequency transponders. Generally, these radiofrequency transponders operate in the UHF frequency range (acronym for Ultra High Frequency), i.e. between 300 MHz and 3 GHz. In the case of transport vehicles such as pneumatic tire vehicles, connected objects are mobile components of these transport vehicles. Consequently, they are mobile in operation by traveling in a plane movement around a fixed axis of rotation relative to the transport vehicle. Therefore, in a reference frame linked to the transport vehicle, said transponders travel in loops closed on themselves.

[0003] Document US20210021015A1 shows, in the case of a land vehicle, the installation of an on-board reading system for RFID tags (acronym for Radio Frequency IDentification) and TMS sensors (acronym for Tire Mounted Sensor) located in the tire casings of the mounted assemblies of the land vehicle. This system is composed of a radiofrequency reader / transmitter galvanically connected to four transmission lines to radiofrequency antennas, each covering a certain geographical area. The radiofrequency antennas are fixed integrally to the fixed part of the land vehicle. This solution requires multiplying the radiofrequency antennas, generally two-dimensional and planar or even three-dimensional. This creates spatial clutter within the land vehicle which is detrimental to the installation of the other components of the land vehicle. In addition, the separation of the various elements (the radiofrequency reader, the transmission line and the radiofrequency antenna) multiplies the connection points between the various elements, which increases the risks of failure of the reading system due to the vibrations and shocks that means of transport generally undergo. Finally, the multitude of assemblies mounted on a land vehicle generates a multiplicity of transmission lines and radiofrequency antennas, which is expensive.

[0004] One of the objects of the invention which follows aims to resolve the problems of reliability and cost of systems for reading mobile radiofrequency transponders within transport vehicles.

[0005] In order to better understand the invention, the circumferential direction S, axial direction A and radial direction R are understood here to be directions defined relative to the rotating reference frame of the mobile assembly around its natural axis of rotation. The radial direction R is the direction moving perpendicularly away from the natural axis of rotation. The axial direction A is the direction parallel to the natural axis of rotation. Finally, the circumferential direction S forms a direct trihedron with the predefined radial and axial directions. Description of the invention

[0006] The invention relates to a transport vehicle comprising a system for reading radiofrequency transponders and at least one mobile assembly capable of ensuring the movement of the transport vehicle relative to the ground on which the transport vehicle is running, comprising a pneumatic tire set in motion around an axis of rotation, the free movement of the at least one mobile assembly taking place in a predominantly two-dimensional plane in a cylindrical frame of reference associated with the at least one mobile assembly whose axial direction is the direction of the axis of rotation, the pneumatic tire defining a median plane which is perpendicular to the axis of rotation, the at least one mobile assembly, preferably the pneumatic tire, being equipped with a radiofrequency transponder. The reading system comprises: - An electrical signal generator emitting at a FO frequency included in the Ultra High Frequency band, coupled to an electrical signal demodulator adapted to a frequency band around FO, mounted on the transport vehicle. At least one bidirectional communication cable, being partly flexible, comprising a conductive core covered with a first dielectric element, itself covered with a conductive assembly, having one end galvanically connected to the reading system, having at its free end a means of capacitive coupling between the conductive core and the conductive assembly via a second dielectric element, adapted to the frequency band of the reading system, the length lo is divided according to a metric whose unit is a wavelength LO defined by the frequency FO. - The at least one cable, being fixed securely to the transport vehicle and externally to the at least one mobile assembly, comprises a radiating part. The arrangement is characterized in that the distance of the radial projection of a first continuous part of the radiating part of the at least one cable on a cylinder, with an axis of revolution coaxial with the axis of rotation, circumscribed to the pneumatic tire is less than or equal to 1 meter, preferably less than or equal to 0.5 meters, in that the distance of the axial projection, in the direction of the axis of rotation, of the first continuous part of the radiating part of the at least one cable on the median plane of the pneumatic tire is less than 2 meters, preferably less than or equal to 1 meter, very preferably less than or equal to 0.5 meters, in that the first continuous part of the radiating part of the at least one cable comprises at least one meander, in that the curvilinear length of the at least one meander is between 0.9 and 1.1 times the half-wavelength LO defined by the communication frequency FO modulo the wavelength LO and in that the distance “P” separating the two ends of the at least one meander is less than a quarter of the wavelength LO.

[0007] The term "free movement" means that the movement is performed without displacement constraints such as an imposed displacement movement. For example, in the case of a statically loaded and rotating mounted assembly, this is the movement of the material points of the mounted assembly outside the contact zone of the pneumatic casing with the ground, commonly called the contact area. In fact, in this zone, the movement of a material point of the pneumatic casing in contact with the ground is guided by the ground as long as the sliding condition is not reached, so we are in imposed displacement, which does not fall within the definition of free movement.

[0008] First of all, the moving assembly is the subassembly of the transport vehicle used to move the transport vehicle relative to the ground. The moving assembly comprises a pneumatic band driven in rotation around an axis of rotation by non-deformable parts, i.e. more rigid than the pneumatic tire such as a rim.

[0009] The radiofrequency transponder which can be an RFID tag or another electronic device with its own energy source or passive. The radiofrequency transponder is fixed on the mobile assembly of the transport vehicle. This can be for example an RFID tag in a tire casing, a TPMS sensor (Tire Pressure Monitoring System) attached to the wheel or any electronic object communicating by radiofrequency equipped with a radiofrequency antenna located on a mobile assembly. In order to read this electronic object linked to the mobile assembly therefore in motion in the transport vehicle, the invention discloses placing an on-board reading system on the transport vehicle external to the mobile assembly. Therefore it is not linked to the movement of the mobile assembly.This reading system comprises a first device comprising a transmitter / receiver of electrical signals at a fixed frequency and a demodulator of electrical signals on a frequency band around the fixed frequency. This first device is connected to a bidirectional communication cable. This cable is composed of a conductive core, hollow or solid, generally metallic and a second hollow conductive tube coaxial with the conductive core. A first dielectric element separates the two conductive components. One end of the cable is connected to the electronic transmission / reception device while the other end is free. This cable comprises at least one radiating part, that is to say that it functionally transmits or receives radio waves. externally to the hollow conductive tube. The cable is equipped at its free end with a means of capacitive coupling between the conductive core and the conductive assembly constituted by the hollow conductive tube, by means of a second dielectric element, adapted to the frequency band of the reading system.

[0010] This type of bidirectional communication cable uses surface radio waves through this capacitive coupling method. This makes it possible to have a bidirectional cable with no specific features on its surface on the radiating part. Thus, in the event of significant deformation of the cable during its installation in the transport vehicle, the communication functionality of the cable is not affected as could be the case with a leaky feed antenna cable, the distribution and shapes of the holes passing through the conductive tube of which are more sensitive to the deformation of the bidirectional cable. In addition, this technical solution is more economical since the production of the holes on the conductive tube is significantly more expensive than the installation of an electrical reflection device by capacitive coupling at the end of a coaxial cable.

[0011] This type of cable is described in patent application US2016 / 0197408A1 comprising at its free end an electrical reflection device by capacitive coupling consisting of a conductive component connected to the conductive core and possibly separated from the conductive tube by a second dielectric material generating capacitive coupling. The length of the conductive component is generally a quarter of the wavelength of the radio waves emitted and received by the cable antenna. This device creates surface radio propagation waves on the conductive tube in the opposite direction to that emitted by the signal generator up to a surface wave attenuation zone made by magnetized rings, generally made of ferrite, mounted axially outside the cable.

[0012] The invention is based first of all on the particular arrangement of the reading system and in particular of the radiating part of the bidirectional communication cable in relation to the path followed by the radiofrequency transponder driven in movement by the mobile assembly. Indeed, the spatial distance between the radiating part of the cable and the radiofrequency transponder must be less than a certain distance, preferably one meter, during a part of the loop described by the radiofrequency transponder during the travel of the mobile assembly so that radiofrequency communication can be established between the reading system and the radiofrequency transponder. This is ensured through two conditions linked to the structure of the mobile assembly. Indeed, the mobile assembly having a predominantly two-dimensional movement, in the reference frame linked to the mobile assembly, outside the zones with imposed movement, it is possible to define a median plane to the tire of the mobile assembly which has the property of being perpendicular to the axis of rotation of the mobile assembly and of separating the mobile assembly into two symmetrical parts with respect to the median plane.The term "predominantly bidirectional movement" here means that the distance traveled by a material point of the moving assembly between two instants, decomposed on an orthonormal reference frame linked to the moving assembly, has a smaller component than the other two. Generally, this component is that carried by the direction of the axis of rotation of the moving assembly. The first condition is that a continuous sub-part of the radiating part of the communication cable is not further than 2 meters from the median plane attached to the tire of the moving assembly along the direction of the axis of rotation of the moving assembly. Of course, the closer the location of the continuous part of the radiating part of the cable is to the radiofrequency transponder, the better the radiofrequency communication between the two radiofrequency devices.

[0013] Then, the pneumatic tire of the mobile assembly being driven by a pure rotational movement around its axis of rotation, it is necessary to control the distance between the continuous part of the radiating part of the bidirectional communication cable and the pneumatic tire of the mobile assembly. To this end, a second projection condition must be respected. It, for the area of ​​the pneumatic tire rotating around its axis of rotation, consists of defining the maximum radial projection distance R of the continuous part of the radiating part of the bidirectional communication cable on the closest surface of the pneumatic tire of the mobile assembly, which corresponds to the radially external surface of the pneumatic tire relative to its axis of rotation.

[0014] When these conditions are met during a part of the loop described during the path of the radiofrequency transponder fixed on the mobile assembly, it is ensured that the continuous part of the radiating part of the bidirectional communication cable is potentially in bidirectional communication with the radiofrequency transponder on this part of the loop; what is more, this communication is spatially periodic since it is repeated at each loop. Of course, the more extensive this part of the loop is, the better the communication between the two components from a temporal point of view. Preferably, the condition is respected over the entire loop describing the path of the radiofrequency transponder.

[0015] Finally, it is necessary that the continuous part of the radiating part of the bidirectional communication cable that is located in this spatial zone with respect to the mobile assembly comprises at least one meander. The meander is defined by a width named "1" and a length named "L". The length "L" is defined with respect to the axial direction of the radiating part of the cable outside the meander zones. One of the ends of the length "L" begins at the change in curvature of the cable and which initiates the meander. The other end is defined by the point of the meander that is the furthest, that is to say having the largest orthogonal projection, with respect to the axial direction of the cable.The width "1" of the meander is defined using each axial average, according to the direction of the cable, of the points of the meander defining the outward or return of the meander, that is to say the set of points of the cable located between the two ends defining the length "L" of the meander on the outward or return of the meander. The distance between these two axial averages, according to the axial direction of the cable, determines the width "1" of the meander. We will call the entry end of the meander, according to the direction of propagation of the radio waves provided by the transmission / reception system, the first point of the meander where the tangent has a main component carried by the direction of the length "L" of the meander.The exit end of the meander will be called, according to the direction of propagation of the radio waves provided by the transmission / reception system, the last point of the meander where the tangent has a main component carried by the direction of the length "L" of the meander. The distance "P" is measured between the entry end and the exit end of the meander.

[0016] This meander makes it possible to constitute an improved communication zone between the bidirectional communication cable and the transponder in a radiofrequency emission communication mode emanating from the reading system, i.e. triggered by the reading system. Thus, this makes it possible to establish communication with the radiofrequency transponder, in particular when the latter is passive, by providing a sufficient quantity of energy for the latter to wake up and establish communication when the radiofrequency transponder is near this meander during its path associated with the movement of the mobile assembly. Indeed, this meander makes it possible to create a narrow spatial zone, located between the input end and the output end of the meander, in which the electric field E generated by the radiating part of the communication cable is stable and higher in amplitude than that generated outside the meander or even within the meander.

[0017] This increase in the electric field E at the meander, between the input end and the output end, is only possible because of the particular distance P between its two points of the meander which creates an air gap, that is to say an oppositely charged system, positive and negative charges facing each other, like a capacitor, when the curvilinear length of the meander is close to the half wavelength LO associated with the communication frequency FO of the reading system. The increase in the amplitude of the electric field E provides an increase in the radioelectric energy towards the radiofrequency transponder which allows it to be activated in communication mode. In the context of a passive radiofrequency transponder such as a passive RFID radio tag, the energy captured by the radiofrequency transponder is used to transmit the return radiofrequency message from the radiofrequency transponder.During the reception phase of the radiofrequency message emanating from the radiofrequency transponder, the linear radiating part of the communication cable is sufficient to receive the return message as long as the distance between the two elements remains reasonable. Therefore, this meander is to be used mainly in areas where communication with the radiofrequency transponder is difficult. For example, when one wishes to interrogate a radiofrequency transponder that is spatially distant from the radiating part of the communication cable or when the environment of the vehicle or the mobile assembly is not favorable to radiofrequency communication due, for example, to elements. electrically conductive. Thus, a radiofrequency transponder located both on the outer side of the tire and on the outside of the transport vehicle, only the positioning of the radiating part of the cable radially outside the tire is possible. However, the top of the tire, the most radially outer part of the tire relative to its axis of rotation includes a metallic top, often of radial design which is detrimental to radiofrequency communication. In these specific cases, the presence of a meander still makes it possible to interrogate the radiofrequency transponder of the mobile assembly and to receive its radiofrequency response via the first continuous part of the radiating part of the communication cable.

[0018] It should be noted that the arrangement of the rest of the meander, that is to say outside the entry and exit end points, only slightly modifies the electric field E. Therefore, this meander can easily adapt to any complex and dense environment such as a motor vehicle. Only the distance between the entry and exit ends, the orientation of the line defined by these two ends and the curvilinear length between these two ends need to be controlled to ensure the function of the meander in terms of improving radiofrequency communication. Finally, this type of meander also makes it possible to minimize the electrical energy consumption of the communication cable. Indeed, the radioelectric radiation is localized and not extended, which saves energy.Of course, the smaller the distance "P" between the exit and entry ends of the meander, the stronger the electric field E generated by these points, to the detriment of the duration of exposure of the radiofrequency transponder to this enhanced electric field E. To increase the duration of exposure to this electric field E, it is sufficient to multiply the meanders and in particular to make these meanders contiguous. For example, this can be achieved by folding the cable in the form of an "S" which is the addition of two contiguous meanders whose loops are opposite. The S shape makes it possible not to spatially shift the two meanders due to the curvature of the cable. This technique makes it possible to extend the communication zone with enhanced electric field E of each meander.

[0019] Furthermore, it is preferable that the continuous part of the radiating part of the two-way communication cable which is located in the spatial area around the mobile assembly has a curvilinear length greater than a unit of cable length. The unit of cable length is defined by the wavelength LO associated with the frequency FO of emission of the radio signal by the reading system propagating in a medium of given relative dielectric permittivity. Thus, it is ensured that the length of the antenna in the spatial zone delimited by one of the two geometric conditions is suitable for transmitting and receiving radio signals to and from the radiofrequency transponder fixed on the mobile assembly. Of course, the greater the length of the continuous part of the radiating part of the bidirectional communication cable, the better the communication between the reading system and the radiofrequency transponder.

[0020] According to a specific embodiment, the radiating part of the at least one cable comprising at least one second continuous part separate from the first continuous part, the distance of the radial projection of the at least one second continuous part of the radiating part of the at least one cable on a cylinder, with an axis of revolution coaxial with the axis of rotation of the at least one second mobile assembly, circumscribed to the pneumatic tire of the at least one second mobile assembly is less than or equal to 1 meter, preferably less than 0.5 meters and the distance of the axial projection, in the direction of the axis of rotation of the at least one second mobile assembly, of the at least one second continuous part of the radiating part of the at least one cable on the median plane of the pneumatic tire of the at least one second mobile assembly is less than 2 meters, preferably less than 1 meter, very preferably less than 0.5 meters.

[0021] This is a configuration where the bidirectional communication cable is able to interrogate mobile assemblies of the same transport vehicle that are far from each other so that the same continuous part of the radiating part of the communication cable cannot interrogate both mobile assemblies. The conventional solution would then be to add a second bidirectional communication cable and to position a continuous part of the radiating part of this second cable in the appropriate geographical area of ​​the second mobile assembly, which is expensive. The solution here is to employ the same bidirectional communication cable, which limits the number of galvanic connections to the electrical signal transmitter / receiver of the reading system. This cable is then equipped with a second continuous radiating part separate from the first continuous part. However, it can be the same radiating part of the cable. Thus, the same cable interrogates and receives information from each radiofrequency transponder, each associated with a different mobile assembly. To create an extended radiating spatial zone, it is sufficient to pass the radiating part of the cable several times over the same spatial zone in order to create a continuous zone. This creates an extended radiating zone allowing easy communication with the transponders of the transport vehicle crossing the spatial zone. Of course, it is possible to create several extended radiating spatial zones, separate from each other using this technique. Between these spatial zones, the cable has a lesser radiating behavior which nevertheless allows the transmission of radio signals along the cable to the reader.Of course, it is entirely possible to multiply the continuous and radiating parts along the length of the communication cable in order to communicate with several mobile assemblies geographically distant from each other to communicate with all the radio frequency transponders of the transport vehicle, whether these are linked to a mobile assembly of the transport vehicle or not. Similarly, a continuous part of the radiating part of the bidirectional communication cable can communicate with different mobile assemblies as long as these are located at the correct distance from the continuous part of the radiating part of the cable.

[0022] According to a specific embodiment, in the radiating portion of the cable, the conductive assembly is covered by a second conductive assembly which is connected to ground.

[0023] This limits the electromagnetic radiation from the cable in the transport vehicle, which may be necessary depending on the desired electromagnetic compatibility of the transport vehicle.

[0024] According to a particular embodiment, the at least one second continuous part of the radiating part of the at least one cable comprises at least one meander, the curvilinear length of the at least one meander of the at least one second part is between 0.9 and 1.1 times the half-wavelength L0 defined by the communication frequency F0 modulo the wavelength L0, the distance “P” separating the two ends of the at least a meander of the at least one second part is less than a quarter of the LO wavelength.

[0025] It is preferable that the second continuous portion of the radiating portion of the bidirectional communication cable that is located near a mobile assembly comprises at least one meander. The meander is defined by a width named "1" and a length named "L". The length "L" is defined relative to the axial direction of the radiating portion of the cable outside the meander zones, said cable being in the zone defined by the radial projection and the axial projection of the cable on the mobile assembly. One of the ends of the length "L" begins at the change in curvature of the cable that initiates the meander. The other end is defined by the point of the meander that is furthest, i.e. having the largest orthogonal projection, relative to the axial direction of the cable.The width "1" of the meander is defined using each axial average, according to the direction of the cable, of the points of the meander defining the outward or return of the meander, that is to say the set of points of the cable located between the two ends defining the length "L" on the outward or return of the meander. The distance between these two axial averages, according to the axial direction of the cable, determines the width "1" of the meander. The entry end of the meander will be called, according to the direction of propagation of the radio waves provided by the transmission / reception system, the first point of the meander where the tangent has a main component carried by the direction of the length "L" of the meander. The exit end of the meander will be called, according to the direction of propagation of the radio waves provided by the transmission / reception system, the last point of the meander where the tangent has a main component carried by the direction of the length "L" of the meander.The distance “P” is measured between the inlet end and the outlet end of the meander.

[0026] This meander allows for an improved communication zone to be formed between the bidirectional communication cable and the transponder in a radiofrequency emission communication mode emanating from the reading system, i.e. triggered by the reading system. Thus, this allows communication to be established with the radiofrequency transponder, in particular when the latter is passive, by providing a sufficient quantity of energy for the latter to wake up and establish communication when the radiofrequency transponder is in the vicinity of this meander during its path associated with the movement of the second mobile assembly. In fact, this meander makes it possible to create a narrow spatial zone, located between the entry end and the exit end of the meander, in which the electric field E generated by the radiating part of the communication cable is stable and higher in amplitude than that generated outside the meander or even within the meander.

[0027] Indeed, this meander allows to create an extended spatial zone, proportional to the length "L" of the meander, in which the electric field E generated by the radiating part of the communication cable is stable and higher in amplitude than that generated outside the meander. This increase of the electric field E at the level of the meander, between the input end and the output end is only possible because of the particular distance P between its two points of the meander which creates an air gap, that is to say an oppositely charged system, positive and negative charges facing each other, like a capacitor, when the curvilinear length of the meander is close to the half wavelength LO associated with the communication frequency FO of the reading system.

[0028] The increase in the amplitude of the electric field E provides an increase in the radioelectric energy towards the radiofrequency transponder which allows it to be activated in communication mode. In the context of a passive radiofrequency transponder such as an RFID radio tag, the energy captured by the radiofrequency transponder is used to transmit the return radiofrequency message from the radiofrequency transponder. In the reception phase of the radiofrequency message emanating from the radiofrequency transponder, the linear radiating part of the communication cable is sufficient to capture the return message as long as the distance between the two elements remains reasonable. Therefore, this meander is to be used mainly in areas where communication with the radiofrequency transponder is difficult.For example, when it is desired to interrogate a radiofrequency transponder spatially distant from the radiating part of the communication cable or when the environment of the vehicle or the mobile assembly is not favorable to radiofrequency communication due, for example, to electrically conductive elements. In these specific cases, the presence of a meander still makes it possible to interrogate the radiofrequency transponder of the mobile assembly and to receive its radiofrequency response via the second continuous part of the radiating part of the communication cable.

[0029] It should be noted that the arrangement of the rest of the meander, that is to say outside the entry and exit end points, only slightly modifies the electric field E. Therefore, this meander can easily adapt to any complex and dense environment such as a motor vehicle. Only the distance between the entry and exit ends, the orientation of the line defined by these two ends and the curvilinear length between these two ends need to be controlled to ensure the function of the meander in terms of improving radiofrequency communication. Finally, this type of meander also makes it possible to minimize the electrical energy consumption of the communication cable. Indeed, the radioelectric radiation is localized and not extended, which saves energy.Of course, the smaller the distance "P" between the exit and entry ends of the meander, the stronger the electric field E generated by these points, to the detriment of the duration of exposure of the radiofrequency transponder to this enhanced electric field E. To increase the duration of exposure to this enhanced electric field E, it is sufficient to multiply the meanders and in particular to make these meanders contiguous. For example, this can be achieved by folding the cable in the form of an "S" which is the addition of two contiguous meanders whose loops are opposite. The S shape makes it possible not to spatially shift the two meanders due to the curvature of the cable. This technique makes it possible to extend the communication zone with the enhanced electric field E generated by each meander.

[0030] Furthermore, it is preferable that the continuous part of the radiating part of the bidirectional communication cable which is located in the spatial zone around the second mobile assembly has a curvilinear length greater than one unit of cable length. The unit of cable length is defined by the wavelength associated with the frequency F0 of emission of the radio signal by the reading system propagating in a medium of given relative dielectric permittivity. Thus, it is ensured that the length of the antenna in the spatial zone delimited by one of the two geometric conditions is suitable for transmitting and receiving radio signals to and from the radiofrequency transponder fixed on the mobile assembly. Of course, the greater the length of the continuous part of the radiating part of the bidirectional communication cable, the better the communication between the reading system and the radiofrequency transponder.

[0031] According to an advantageous embodiment, the radiating part of the at least one cable comprises at most 7 meanders, preferably at most 5 meanders.

[0032] The multiplication of meanders limits the radiating character of the cable outside the areas where the meanders are located, which can be detrimental to the interrogation of the radiofrequency transponders of the transport vehicle not located, during their movement, in the spatial zones of the continuous parts of the radiating part of the communication cable. An alternative to compensate for this low emission radiation of the cable consists of increasing the electrical power of the reading system. But at the same power supplied to the reading system, it is preferable to limit the number of meanders to ensure sufficient radiofrequency communication over the total length of the radiating part of the bidirectional communication cable.

[0033] According to another advantageous embodiment, each continuous part of the radiating part of the at least one cable comprises at most 3 meanders, preferably at most 2 meanders.

[0034] In this same logic of uniformity of the communication capacity of the cable, it is preferable that each continuous part of the radiating part of the cable does not have more than 3 meanders and very preferably not more than 2. Thus, the radiation power is distributed between the various continuous parts if there are several of them. In addition, radioelectric transmission power is left in the areas without meanders.

[0035] Advantageously, the radiofrequency transponder associated with the at least one mobile assembly comprising a radiofrequency antenna comprising at least one wire strand defining a first longitudinal axis, each meander of the first and / or the at least one second continuous part of the radiating part of the at least one cable defining a straight line D defined by the two ends of the at least one meander, the angle formed by the direction vectors of the first longitudinal axis and of the straight line D is less than + / - 30 degrees, preferably less than + / - 20 degrees over at least part of the closed path described by the at least one mobile assembly (1).

[0036] In the particular case where the radiofrequency transponder is equipped with a wire antenna, it is necessary that the directions of the first longitudinal axis and the direction of the line D are substantially parallel to each other in order to ensure a electromagnetic coupling between the radiofrequency transponder and the effective part of the meander. Indeed, the enhanced electric field E, generated by the meander is oriented along the line D. Thus, the wire antenna of the transponder is substantially aligned with the enhanced electric field E generated by the meander. Ideally, the wire antenna should be collinear with the enhanced electric field E for the coupling efficiency to be maximal. However, the level of communication between the two antennas remains completely suitable as long as the angle formed by the two directions does not deviate by more than 30 degrees. This is preferable when the radiofrequency transponder is passive, that is to say without its own source or production of electrical energy. Indeed, the electromagnetic coupling then serves to activate the radiofrequency transponder by transmitting energy to it before it transmits.

[0037] Of course, since the radiofrequency transponder is in motion while the reading system is fixed relative to the transport vehicle, the angular condition is not necessarily respected over the entire path described by the radiofrequency transponder. However, it is sufficient for this condition to be achieved over a part of the path of the moving assembly for the radiofrequency communication between the two electronic systems to be effective.

[0038] According to a first very specific embodiment, the at least one mobile assembly being capable of describing a rotational movement around a single axis of rotation defining a cylindrical reference frame around this axis of rotation, the first longitudinal axis of the radiofrequency antenna of the radiofrequency transponder associated with the at least one mobile assembly having its main component oriented circumferentially in the cylindrical reference frame, the at least one meander associated with the first and / or the at least one second continuous part of the radiating part of the at least one cable being arranged radially externally to the mobile assembly relative to the axis of rotation, the straight line D of the at least one meander has its main component oriented circumferentially in the cylindrical reference frame of the mobile assembly.

[0039] When the first longitudinal axis of the radio frequency transponder of the mobile assembly is mainly circumferential in the cylindrical frame of reference of the mounted assembly, as can be found in the case of buried RFID radio tags in the structure of the tire at the sidewall or the lower zone, and the meander is located radially outside the tire with respect to the axis of rotation of the moving assembly, it is advisable to position the meander so that the straight line D has a predominantly circumferential direction in the cylindrical frame of reference of the moving assembly. As a result, it is certain that during the rotational movement of the moving assembly, the directions of the first longitudinal axis of the wire antenna of the radiofrequency transponder and of the enhanced electric field E generated by the meander align substantially with a part of the loop described by the movement of the radiofrequency transponder.

[0040] Very specifically to this first specific embodiment, the radiofrequency antenna of the radiofrequency transponder associated with the at least one mobile assembly and the at least one meander associated with the first and / or the at least one second continuous part of the radiating part of the cable projecting in the same circumferential plane, the projection of the antenna of the radiofrequency transponder intersects at least the projection of the line D of the at least one meander.

[0041] In the case where the radiofrequency transponder of the mobile assembly is buried in the rubber compounds of the tire as may be the case for an RFID radio tag, the size of the radiofrequency antenna of the radiofrequency transponder, defined by the wire strand(s) and being linked to the radiocommunication frequency F0 of the radiofrequency transponder, is reduced due to the relative dielectric permittivity of the rubber compounds of the tire. Indeed, the relative dielectric permittivity of the rubber compounds is different from that of air, which modifies the wavelength of the radio waves. In this case, depending on the communication frequency F0, it is possible that the size of the radiofrequency antenna is less than the distance “P” between the entry and exit ends of the meander.Therefore, it is possible that the entire radiating antenna of the transponder is placed in the enhanced electric field E generated by the meander, which increases the power transmitted to the radio frequency transponder.

[0042] According to a second very specific embodiment, the mobile assembly being capable of describing a rotational movement around a single axis of rotation defining a cylindrical reference frame around this axis of rotation, the first longitudinal axis of the radiofrequency antenna of the radiofrequency transponder associated with the at least one mobile assembly having its main component oriented circumferentially in the cylindrical reference frame, the at least one meander associated with the first and / or the at least one second continuous part of the radiating part of the cable being arranged axially externally and radially internally to the mobile assembly relative to the axis of rotation, the straight line D of the at least one meander has its main component oriented circumferentially in the cylindrical reference frame of the mobile assembly.

[0043] When the first longitudinal axis of the radiofrequency transponder of the mobile assembly is mainly circumferential in the cylindrical reference frame of the mounted assembly, as can be found in the case of RFID radio tags buried in the structure of the tire at the sidewall or the lower zone, and the continuous part of the radiating part of the communication cable is located axially externally and radially internally to the tire relative to the axis of rotation of the mobile assembly, it is advisable to place the meander so that the straight line D has a mainly circumferential direction in the cylindrical reference frame of the mobile assembly.Therefore, it is certain that during the rotational movement of the mobile assembly, the directions of the first longitudinal axis of the wire antenna of the radiofrequency transponder and of the electric field generated by the meander align substantially with a part of the loop described by the movement of the radiofrequency transponder.

[0044] Very specifically to this second specific embodiment, the radiofrequency antenna of the radiofrequency transponder associated with the at least one mobile assembly and the at least one meander associated with the first and / or the at least one second continuous part of the radiating part of the cable projecting in the same axial plane, the projection of the antenna of the radiofrequency transponder intersects at least the projection of the line D of the at least one meander.

[0045] In the case where the radio frequency transponder of the mobile assembly is buried in the rubber compounds of the tire as may be the case for an RFID radio tag, the size of the radio frequency antenna of the transponder radio frequency, defined by the wire strand(s) and being linked to the radiocommunication frequency FO of the radiofrequency transponder, is reduced due to the relative dielectric permittivity of the rubber compounds of the tire. Indeed, the relative dielectric permittivity of the rubber compounds is different from that of air, which modifies the wavelength of the radio waves. In this case, for example, depending on the communication frequency FO, it is possible that the size of the radiofrequency antenna is less than the distance "P" between the entry and exit ends of the meander. As a result, it is possible that the entire radiating antenna of the transponder is placed in the electric field E generated by the meander, which increases the communication power of the radiofrequency transponder.

[0046] Advantageously, the radiofrequency transponder includes an RFID tag.

[0047] This is a particular embodiment where the radiofrequency transponder includes an RFID radio tag (acronym for Radio Frequency Identification). This is small in size since it requires few components to operate, which allows it to be installed inside the tire of the moving assembly or on its outer surface via a specific connection patch. The main function of such an electronic system is to convey identification information, generally coded in the non-erasable memory of the electronic system. In a specific embodiment, the RFID radio tag is passive, without its own energy source. In this particular case, the interrogation phase of the RFID tag consists first of all in transferring radioelectric energy to it to become operational and then respond to its interrogation.

[0048] Advantageously, the mobile assembly being capable of describing a rotational movement around an axis of rotation, each continuous part of the at least one cable describes an angular sector around the axis of rotation at least greater than 30 degrees, preferably greater than 60 degrees, very preferably greater than 120 degrees.

[0049] In the case of a mobile assembly rotating around a single axis of rotation, it is preferable that, in a rotating frame associated with the single axis of rotation, the continuous part of the radiating part of the two-way communication cable, including the meander, extends over an angular sector of at least 30 degrees. Thus, depending on the speed of rotation of the mobile assembly around its single axis of rotation, a certain communication duration is ensured between the radiofrequency transponder rotating with the mobile assembly and the fixed reading system in the transport vehicle. Of course, the larger the angular sector, the greater the communication duration is increased at a given rotation speed.

[0050] Preferably, the continuous part of the radiating part of the at least one cable is fixed to the at least one wall delimiting the cavity of the means of transport accommodating the mobile assembly.

[0051] In the case of a mobile assembly rotating around a single axis of rotation such as that comprising a pneumatic casing in a car, the direct or indirect fixing of the continuous part of the radiating part of the bidirectional communication cable on the wheel arch is preferred. Indeed, the wheel arch delimits the cavity where the assembly mounted on the vehicle will be connected in use. Generally this component is not metallic which implies no shielding effect or radio interference. The propagation of radio waves between the communication cable and the transponder is favored by the absence of metallic or conductive components interposed between the two antennas. Finally, the cavity naturally constitutes a free zone for the installation of the communication cable in an extremely confined space such as that of a motor vehicle.

[0052] Very preferably, the continuous part of the radiating part of the at least one cable extends at a constant radial distance from the axis of rotation of the mobile assembly.

[0053] This condition ensures reliability in the radio frequency communication between the two components in the case of a passive radio frequency transponder, such as an RFID tag, in the tire. Indeed, it is commonly accepted to position the RFID tag on the sidewall of the tire in a predominantly circumferential direction relative to the axis of rotation of the mounted assembly. In addition, the shape of the walls delimiting the receiving cavity of the mounted assembly generally follows this geometric condition. Thus, also the communication between the two antennas is optimized both in terms of duration and quality and keeping constant the spatial distance between the radiofrequency transponder and the continuous part of the radiating part of the communication cable

[0054] Preferably, the radiofrequency transponder transmits via a subcarrier frequency.

[0055] These are application cases where the radiofrequency transponder uses the radiofrequency transmission signal it receives to transmit the response to its interrogation. This mode of operation is particularly used in passive radiofrequency transponders such as RFID tags, i.e. those which do not have their own energy source for transmission. These communication modes use various modulations depending on whether the aim is to promote the communication sensitivity of the bidirectional communication cable or the communication speed between the two radiofrequency devices. Modulation is mainly characterized by two quantities: the number of transitions for a binary state, physically this is a change in the state of the impedance of the radiofrequency transponder of the electronic chip of an RFID tag for example, which induces a modification of the amplitude and phase of the return signal, and the unit period for observing the transitions.By promoting the sensitivity of the communication cable, it is advisable to work on a large number of transitions for a binary state over a high unit period. For example, Miller 8 coding applicable in UHF RFID allows to gain 5 to 10 dBm of sensitivity. Conversely, limiting the number of transitions, down to a single transition per unit period over a short unit period promotes the throughput of transactions between the radiofrequency transponder and the bidirectional communication cable, in fact maximizes it. FMO modulation, i.e. one transition per unit period of 7.6 ps for example, allows to increase by a factor of 10 the reading rate of the bidirectional communication cable compared to a Miller 8 modulation. In the case of an RFID tag, it is the reading system and in particular the electrical signal generator which controls the modulation scheme on which the radiofrequency transponder will have to communicate.This is not a choice of the radio frequency transponder but an obligation given to it by the reading system.

[0056] Very preferably, the subcarrier frequency of the radiofrequency transponder comprises a number of transitions less than 5, preferably a single transition over the unit period of the subcarrier frequency.

[0057] Very preferably, the subcarrier frequency of the radiofrequency transponder includes a unit period less than 10 ps, ​​preferably less than 8 ps.

[0058] By opting for short periods and few transitions, the radiofrequency communication rate between the radiofrequency transponder and the bidirectional communication cable is favored, i.e. the reading rate of the continuous part of the radiating part of the communication cable, which is favorable in the context of the arrangement envisaged. Indeed, the arrangement is characterized by reading distances between the bidirectional communication cable and the radiofrequency transponder of less than 1 meter over a short coupling time between the two devices due to the relative movement of the radiofrequency transponder mounted on the mobile assembly.The inventor found that this modulation mode is then better, particularly for transport vehicles when the continuous part of the radiating part of the communication cable is in direct contact with the pneumatic tire of the moving assembly for high or very high vehicle running speeds. Brief description of the drawings

[0059] The invention will be better understood on reading the following description, given solely by way of non-limiting example and made with reference to the appended figures in which the same reference numbers designate identical parts throughout and in which: - Fig. 1 shows a perspective view of the communication space of the radiating part of the communication cable with the moving assembly consisting of a pneumatic tire mounted and inflated on a rim which is not shown. - Fig. 2 shows an embodiment of the bidirectional communication cable of the reading system according to the invention. Fig. 3 shows a perspective view of the installation of the reading system in a motor vehicle. - Fig. 4 shows a cross-sectional view of a tire equipped with an RFID tag. - Fig. 5 shows an example of a radio frequency transponder, in this case an RFID tag. - Fig. 6a to 6c show an example of a continuous part of the radiating part of the cable at the level of a mobile assembly. - Fig. 7 shows a dimensional description of a meander of the bidirectional communication cable. Detailed description of embodiments

[0060] In Fig. 1 a pneumatic tire 12 is shown representing the deformable part of a mobile assembly 1 consisting of the pneumatic tire mounted and inflated on a rim, the rim not being shown here. The pneumatic tire 12 rotates around a natural axis of rotation 102. The pneumatic tire 12 defines a median plane 101 which is perpendicular to the axis of rotation 102, separating the pneumatic tire 12 into two sub-parts symmetrical with respect to the median plane 101. This pneumatic tire 12 is equipped with a radiofrequency transponder of the RFID type, that is to say without its own energy source, used to measure the inflation pressure of the mobile assembly using a pressure sensor which corresponds to an electronic device of the RFID sensor type. This pneumatic tire 12 also comprises an active sensor of the TPMS type mounted on the valve of the rim.The radial, azimuthal and axial position of these radiofrequency devices are generally arbitrary in the mobile assembly.

[0061] The pneumatic tire 12 is circumscribed in a cylinder 108 with an axis of revolution 102 resting on the radially outermost position of the top of the pneumatic casing relative to the axis of rotation 102. Here, the pneumatic tire 12b is inflated but not statically loaded, the cylinder 108 rests on a multitude of points of the top equally distributed over the perimeter of the top.

[0062] The implantation space 104 of the continuous part of the radiating part of the bidirectional communication cable can then be defined as being a cylinder with an axis of revolution coaxial with the axis 102, extending radially with respect to the axis 102 from the outer surface of the cylinder 108 at a distance R materialized by the gray arrow represented in the median plane 101. This cylinder 104 is straight since it is limited by flat faces collinear with the median plane 101 located on either side of the median plane 101 at an axial distance A from the median plane 101 in the direction of the axis 102. These axial distances A are visualized by gray arrows carried by the axis 102.It is imperative to position a continuous part of the radiating part of the directional communication cable, preferably of a length of at least one unit of length of the cable, defined by the transmission frequency F0 of the reading system, in the right cylinder 104 so that the radiofrequency devices of the mobile assembly can communicate with the reading system on board the means of transport using said bidirectional communication cable.

[0063] Fig. 2 shows a bidirectional communication cable 32 according to a first configuration functioning perfectly well, and not only, for RFID tag type applications.

[0064] The cable 32 includes an elongated bipolar coaxial conductive structure 312 with an electrically conductive inner conductor 314 and an electrically conductive sheath conductor 316 coaxially surrounding the inner conductor 314. In the illustrated example, the inner conductor 314 is cylindrical and the sheath conductor 316 is hollow and cylindrical.

[0065] The inner conductor 314 like the sheath conductor 316 is formed of a metallic material, in which an electrically insulating intermediate layer (for example plastic) is advantageously present radially between the inner conductor 314 and the sheath conductor 316 along the length of the conductive structure 312.

[0066] A first end 318 of the conductive structure 312 is provided for connecting a transmitter and / or a receiver of the reading system for an antenna signal to be transmitted using the cable 32 or an antenna signal to be received by the cable 32. The cable 32 is provided with a conventional coaxial plug 320, which coaxial plug provides an electrical connector for the inner conductor 314 and for the sheath conductor 316 at this first end 318 in a conventional manner.

[0067] In this configuration, an extension 324 of inner conductor 314, which is integrally formed with inner conductor 314 in the illustrated example and is therefore electrically connected to inner conductor 314, is provided at an opposite second end 322 of conductive structure 312. This extension 324 extends out of sheath conductor 316, starting from the second end 322 of conductive structure 312, in a straight line and coaxial with the path of inner conductor 314 and sheath conductor 316 directly before second end 322.

[0068] The inner conductor extension 324 extends to a free end 326 of the inner conductor extension 324, wherein some capacitive coupling from the free end 326 or the inner conductor extension 324 to the jacket conductor 316 exists in the region of the second end 322 thereof, depending on the length of the inner conductor extension 324.

[0069] In a transmission mode of the cable 32, that is to say if an antenna signal to be transmitted is introduced at the level of the coaxial plug 320 of the first end 318, then this antenna signal travels through the conductive structure 312 to the end 322 and is reflected there more or less strongly, to flow back in the form of a linked progressive wave emanating from the second end 322 along the sheath conductor 316 towards the first end 318.

[0070] For a mode of operation chosen accordingly, for example with respect to the frequency and power of the injected antenna signal, it can be achieved that the cable 32 creates an alternating electromagnetic field around it, but radiates relatively little. This cable 32 operates as a traveling wave antenna in a "coupled mode", in order to therefore have good control over the range of the cable 32.

[0071] In the example of Fig. 2, a surface wave damping device 330 is arranged on the outer circumference of the sheath conductor 316, at a distance from the second end 322, at a point between the two ends 318 and 322. This device is formed, in the example illustrated, of a plurality of ferrite rings 332, 334, 336 and 338, which each surround the outer circumference of the sheath conductor 316.

[0072] The ferrite rings 332 to 338 are arranged at a distance from each other when viewed in the longitudinal direction of the conductive structure 312 and advantageously dampen the aforementioned traveling waves, which rise from the second end 322 of the conductive structure 312, when these waves arrive at the location of the damping device 330.

[0073] The damping device 330 formed from the ferrite rings 332 to 338 or their arrangement location in the path of the coaxial conductive structure 312 divides the total length of the conductive structure 312 into a signal conductive section 340 and a radiating section 342, wherein during operation of the cable 32, the section 340 is used to conduct the antenna signal emanating from or to the first end 318, and the section 342 is used to transmit information and / or energy emanating from the cable 32 or to the cable 32.

[0074] The number of ferrite rings and the individual distances between the ferrite rings can be adapted to the respective use case or the operating parameters of the 32 cable.

[0075] It may also be provided that at least one ferrite ring, in the case of a plurality of ferrite rings, preferably at least the "first" ferrite ring, closest to the second end 322, i.e. the ferrite ring 332 in the illustrated example, is arranged such that it can move along the conductive structure 312.

[0076] Therefore, the properties of the damping device thus formed can be influenced or adapted to the actual use case.

[0077] As an alternative or in addition to the ferrite rings 332 to 338, the damping device 330 may, as a departure from the illustrated example, also comprise different damping components, such as for example an electrical network structure consisting of capacitive components and / or inductive and / or resistive elements, which is arranged at a relevant point along the path of the conductive structure 312 and connected to the two sides to sections 340, 342 of the conductive structure 312 going to the first end 318 and to the second end 322.

[0078] A primary cable component 32 is formed by the coaxial conductive structure 312, which may be a flexible or semi-rigid cable that has an "open end" or the mentioned internal conductive extension 324.

[0079] In the area of ​​the inner conductor extension 324, a shielding sheath conductor 316 is removed to some extent in the remaining area of ​​the conductive structure, so that a dipole antenna is created, one arm of which is formed by the inner conductor extension 324 and the other arm of which is formed by the sheath conductor 316. Other embodiments of the capacitive coupling not illustrated here exist.

[0080] The surface wave damping device 330 formed here by one or more ferrite rings limits the effective antenna length for transmission / reception at section 342.

[0081] In addition to adjusting this antenna length, the position of the damping device 330, here the position of the first ferrite ring 332 in particular, also influences the properties of the damping device 330 and therefore the properties of the returning traveling waves.

[0082] It is generally advantageous with respect to the desired generation of return traveling waves if the inner conductor extension 324 has a length that is at least approximately one-quarter wavelength of the antenna signal of interest.

[0083] For a suitable geometry of the cable 32 and a corresponding mode of operation, it can be achieved that the majority of a transmission signal migrates along the "signal transmitter / receiver section" 342 as sheath current, and that comparatively little high-frequency energy is radiated ("coupled mode").

[0084] The length of the inner conductor extension 324 can be chosen such that a desired impedance is defined in combination with the position of the first ferrite ring 332 to obtain as high a return loss of the cable 32 as possible.

[0085] The length of the cable 32 and the lengths of its individual sections mentioned can be provided in such a way that they are suitable for the use case

[0086] In Fig. 2, 11 is the length of the signal conductive section 340, 12 is the length of the surface wave damping device 330, 13 is the length of the signal transmitter / receiver section 342, and 14 is the length of the inner conductor extension.

[0087] The distance dl denotes a distance between the ferrite rings 332 and 334. This distance dl is for example between 5 and 20 mm.

[0088] The sheath conductor 316 of the coaxial conductive structure 312 has at least one opening, this opening is drawn in dotted lines as an example and marked by 339. The distance of the opening 339 from the damping device 330 is marked by d2 and is in the range of 1 to 5 m. However, a plurality of openings 339 may also be arranged distributed along the length of the signal transmitter / receiver section 342 with a mutual spacing of between 0.1 and 5 times the signal wavelength.

[0089] Fig. 3 shows a perspective view of the installation of the reading system 3 in a transport vehicle 2 of the motor vehicle type.

[0090] The motor vehicle 2 is here represented by a transparent volume representing the closed equipped dressed body which corresponds to the complete vehicle from which the axles and the powertrain have been removed. However, on this vehicle 2, we can see four cavities marked 21a-l, 21a-2, 21b-l and 21b-2 each capable of accommodating a mounted assembly of the vehicle. The mounted assembly here includes radiofrequency devices of the RFID tag type and / or TPMS sensor at the level of the tire casing.

[0091] This vehicle 2 also includes the reading system 3 allowing communication with the radiofrequency devices of the mounted assemblies. This reading system 3 includes a first device for transmitting and reading signals electrical devices 31 installed in the vehicle 2 at the level of the apron, which is a wall mainly vertical relative to the ground where the vehicle moves, delimiting the engine compartment of the vehicle located here at the front of the vehicle 2 from the passenger compartment. This device 31 therefore includes the electrical signal transmitter but also the electrical signal demodulator.

[0092] From this device 31, two bidirectional communication cables 32a and 32b depart to the left and right sides of the vehicle 2 respectively. These communication cables are traveling wave cables described in Fig. 2 and are mounted on the device 31 in order to constitute a galvanic connection. Each cable 32a, 32b runs through the structure of the vehicle 2 in order to reach the proximity of at least one cavity 21a-l, 21a-2, 21b-l, 21b-2 for receiving the mounted assemblies. Each cable comprises a signal transmission part from the device 31 and then becomes radiating.

[0093] In fact, as illustrated in Fig. 3, each cable 32a, 32b reaches the proximity of two receiving cavities of the mounted assemblies each corresponding to the front axle and the rear axle of the vehicle 2. At the first cavity 21a-l, the cable 32a has a continuous portion 32a-l which is continuous located at the wheel arch, describing an angular sector around the axis of the front axle of 120 degrees. This portion 32a-l of the communication cable 32a is located in the communication zone of the radiofrequency devices of the mounted assembly to be received in the cavity 21a-1. Thus this portion 32a-l of the communication cable 32a will communicate with the radiofrequency devices of the mounted assembly present in the receiving cavity 21a-l. Here, the continuous portion 32a-l of the cable is located radially outside the mounted assembly. Therefore, although not shown in Fig.3, the continuous part 32a-l comprises a meander whose median direction extends axially relative to the natural axis of rotation of the mounted assembly, when the latter rolls in a straight line, to be accommodated in the cavity 21a-l.

[0094] However, the same cable 32a then extends towards the second receiving cavity 21a-2 located on the left side of the vehicle 2 at the rear axle. At this cavity 21a-2, the cable 32a has a second continuous part 32a-2 radiating located in the communication zone of the radiofrequency devices of the mounted assembly to be accommodated in the cavity 21a-2. The second continuous and radiating part 32a-2 extends angularly around the axis of rotation of the rear axle over an angular sector of 90 degrees. Indeed, the rear axle is not directional here, therefore the mounted assembly moves little angularly during the rolling phase. Consequently, the radiofrequency communication between the continuous and radiating part 32a-2 of the bidirectional communication cable 32a is facilitated compared to that of the part 32a-l where the axle is directional, generating an angular movement of the mounted assembly when turning, for example. These two continuous and radiating parts 32a-l and 32a-2 are separate and each only allows communication with one mounted assembly.However, in the case of a twin-wheel axle as in the case of a utility vehicle in traction mode, the continuous part 32a-2 located near the cavity 21a-2 would allow communication with the various twin-mounted assemblies, located on the same axle and on the same side of the vehicle 2.

[0095] Similarly, due to the symmetry of the motor vehicle 2, the communication cable 32b comprises a radiating portion having two separate continuous portions each communicating with a mounted assembly located respectively on the front axle and the rear axle. As for the cable 32a located on the left side of the vehicle 2, the cable 32b has a meander at the first continuous portion 32b-l. Since the continuous portion 32b-l is located radially outside the mounted assembly, the direction of the median line of the meander extends mainly in the axial direction defined by the axis of the front axle of the vehicle 2.

[0096] The total length of the bidirectional communication cable 32a and 32b does not exceed 5 meters here. The length of the continuous and radiating part 32a-l, 32a-2, 32b-l and 32b-2 is greater than 50 centimeters, corresponding to a quarter of the development of a pneumatic envelope for a private vehicle. This length is beyond the unit length of the cable for radiofrequency communication in UHF at 920 MHz or 2.4 GHz.

[0097] Fig. 4 represents a detailed view of a pneumatic envelope which constitutes the pneumatic tire of a mobile assembly which represents the assembly mounted consisting of a pneumatic casing in an inflated mounted state on a rim. The rim represents the non-deformable part of the mobile assembly. The diagram focuses on the bead 84 of the pneumatic casing. This figure illustrates the positioning of a radiofrequency transponder 100 of the RFID tag type in the outer zone of the pneumatic casing relative to the carcass ply 87.

[0098] The bead 84 is formed by the bead wire 85 around which the carcass ply 87 is wound with a folded portion 88 located in the outer zone of the tire casing. The folded portion 88 of the carcass ply 87 ends with a free edge 881. A mass of rubber 91 called the bead filler is located radially externally and adjacent to the bead wire 85. It has a radially external free edge 911 bearing on one face of the carcass ply 87 (more precisely on the outer calendering of the carcass ply, there is no direct contact between the cords of the carcass ply and the radiofrequency transponder 100). A second mass of rubber 92 called the “reinforcing filler” is adjacent to it. It has two free edges. The first free edge 921 is located radially internally and rests on the upturned part 88 of the carcass ply.The other free edge 922 is located radially outwardly and ends on the face of the ply of the carcass ply 87. Finally, the sidewall 83 covers both the reinforcing padding 92 and the carcass ply 87. The sidewall has a free edge 831 located radially inwardly and ending on the upturned part 88 of the carcass ply.

[0099] On the inner zone of the tire casing, there is the sealed inner rubber 90 which is adjacent to the carcass ply 87 in this configuration. It ends with a free edge 901 adjacent to the carcass ply 87. Finally, a bead protector 93 protects the carcass ply 87 and the radially inner ends 901, 921 and 831 respectively of the sealed inner rubber 90, the reinforcing filling rubber 92 and the sidewall 83. The outer face of this bead protector 93 is able to be in direct contact with the rim hook when mounting the tire casing on the wheel. This bead protector 93 has two radially outer free edges. The first free edge 931 is located in the inner zone of the tire casing 1. The second free edge 932 is located in the outer zone of the tire casing 1.

[0100] The bead 84 of this tire casing is equipped with two RFID tags 100 and 100 bis located in the outer zone of the tire casing. The first radiofrequency transponder 100, previously encapsulated in an electrically insulating coating rubber, is positioned on the outer face of the bead filler 91. It is positioned at a distance of 20 millimeters from the free edge 881 of the upturned portion 88 of the carcass ply which constitutes a mechanical singularity. This positioning ensures a zone of mechanical stability for the electronic member 100 which is beneficial to its mechanical endurance. In addition, its burial within the structure of the mechanical casing provides it with good protection against mechanical attacks from outside the tire.

[0101] The second radiofrequency transponder lOObis, previously encapsulated in an electrically compatible or similar insulating coating rubber with the material of the sidewall 83, is positioned on the outer face of the sidewall. The similarity of material between the sidewall 83 and the coating rubber ensures that the RFID lOObis tag is positioned within and at the periphery of the sidewall 83 during the baking process. The RFID lOObis tag is simply placed on the raw outer face of the sidewall 83 during the production of the tire casing. Pressurizing the raw blank in the baking mold ensures that the RFID lOObis tag is positioned in the baked state as shown. This RFID lOObis transponder is located far from any free edge of a rubber component of the tire casing. In particular, it is distant from the free edge 932 of the bead protector, from the free edge 881 of the carcass ply and from the free edges 911 and 922 of the packing rubbers.Its positioning in the upper part of the bead ensures increased communication performance with an external radiofrequency reader.

[0102] Fig. 5 is an illustration of a radio frequency transponder 100 operating in the frequency range between 860 and 960 MHz intended to be incorporated into a pneumatic envelope by means of an identification patch made of elastomeric materials. To facilitate the radio communication performance and the physical integrity of the radio frequency transponder 100 within the pneumatic envelope, it will be preferable to arrange the axis of revolution of the radiating antenna 10, parallel to the direction U in a direction perpendicular to the wires of the carcass ply of the radial structure tire, in particular if these are metallic.

[0103] The radiofrequency transponder 100 here has a radiating antenna 10 and an electronic part located inside the radiating antenna 10. The electronic part comprises an electronic chip connected to a printed circuit. A primary antenna consisting of a conductive wire is connected to the printed circuit. The opposite face of the printed circuit to the primary antenna comprises a meander-shaped galvanic circuit. Finally, the diameter of the circumscribed cylinder of the primary antenna is 0.8 millimeters. Both the primary antenna and the galvanic circuit on the opposite face of the printed circuit make it possible to adapt the impedance of the primary antenna to that of the electronic card.

[0104] The electronic card thus formed is embedded in a mass 300 of epoxy resin ensuring the mechanical reliability of the electronic components and the electrical insulation of the electronic card. The cylinder circumscribed by the rigid mass 300 has a diameter of 1.15 millimeters and a length of 6 millimeters.

[0105] The length L of the radiating antenna 10 is here 45 millimeters and corresponds to the half-wavelength of the radio waves at the frequency of 915 MHz in a medium with a relative dielectric permittivity approximately equal to 5. The radiating antenna 10 is made using a steel wire 120 with a diameter of 0.225 millimeters coated on the surface with a layer of brass. This steel wire 120 is the wire strand of the radiating antenna of the radiofrequency transponder 100 defining the first longitudinal axis of the radiofrequency transponder 100.

[0106] Here, the radiating antenna 10 is divided into two main zones. The first zone 201 corresponds to the section of the radiating antenna not located at the right of the electronic part. It comprises two sub-zones 201a and 201b surrounding on either side the rigid and electrically insulating mass 300.

[0107] Each sub-zone 201a 201b with a length L1 of 19 millimeters comprises 12 circular turns with a constant winding diameter DI of 1.275 millimeters. This determines inner and outer diameters of 1.05 and 1.5 millimeters respectively. The helix pitch PI of the circular turns is 1.55 millimeters. Thus, the pitch ratio of helix PI on the winding diameter DI of the turns is 1.21. The axially outer ends of each sub-zone 201a and 201b end with two contiguous turns. As a result, the high ratio ensures that the efficiency of the radioelectric properties of the radiating antenna 10 in this zone 201 is maximized. In addition, the contact between the turns located furthest outside the radiating antenna 10 prevents the interlacing of the helical springs with each other during the handling of the radiofrequency transponders. As the majority of the turns of the first zone 201 of the radiating antenna 10 have a ratio greater than 0.8, the radioelectric performance of the radiofrequency transponder 100 is significantly improved.

[0108] On the second zone 202 of the radiating antenna 10 corresponding to the section of the radiating antenna 10 located at the right of the electronic part, the radiating antenna 10 has a length of 7 millimeters. The helical spring has a constant helix pitch P2 of 1 millimeter and a constant winding diameter D2 of 1.575 millimeters. Thus, the internal diameter of the helical spring of the second zone of the radiating antenna is 1.35 millimeters. This makes it possible to have a ratio of the pitch to the constant winding diameter of the order of 0.63. This ratio makes it possible to maximize the inductance of the second zone 202 of the radiating antenna 10 relative to the first zone 201, which allows for better electromagnetic coupling efficiency with the electronic part.

[0109] In this particular case, the internal diameter of the radiating antenna 10, equal to 1.05, of the first zone 201 is less than the diameter of the mass 300, representing the circumscribed cylinder of the electronic part, equal to 1.15 millimeters. As a result, the sub-zones 201a and 201b of the first zone 201 of the radiating antenna 10 represent mechanical stops to the axial movement of the mass 300 inside the radiating antenna 10. The installation of the electronic part will be carried out, in a first embodiment by threading the rigid and insulating mass 300 into the radiating antenna 10.

[0110] Figs. 6a, 6b and 6c are various two-dimensional views of the communication area 104 of the radio frequency transponders of the mounted assembly; which in this example are mainly fixed on the tire 12, and the system of reading mounted on the transport vehicle. The pneumatic tire 12 is mounted on a rim not shown. The mobile assembly thus formed defines a natural axis of rotation 102 and a median plane 101. This mobile assembly is mounted on the axle of the vehicle. Here, we see the mobile assembly located at the right rear of the transport vehicle. The vehicle can move on the ground 600 by means of the pneumatic tire 12. This pneumatic tire 12 here comprises two radiofrequency transponders each located in one side of the pneumatic tire 12 at the level of the lower zone. Thus, one of the sides is located inside the vehicle while the other opens onto the outside of the vehicle in the absence of a bodywork element of the transport vehicle obstructing this opening.During the rotational movement of the mobile assembly, the radiofrequency transponders describe a closed loop 601-1, respectively 601-2, which is similar to a circle whose axis of rotation corresponds to the natural axis of rotation 102 of the tire 12.

[0111] Fig. 6a is a view in the YZ plane of the motor vehicle, which corresponds to a front view of the mobile assembly. Fig. 6b corresponds to a view in the XY plane, which corresponds to a top view of the mobile assembly, and Fig. 6c represents a view in the XZ plane, which corresponds to a side face of the mobile assembly. The radio frequency communication cylinder 104 is visualized in the three figures between the radio frequency transponders of the mobile assembly and the reading system represented by means of the radiating part of the bidirectional communication cable 32a. When the communication cable 32a enters the communication volume 104, this cable becomes the continuous part 32a-2 of the radiating part of the cable 32a for the mobile assembly located at the right rear of the vehicle.The fact that the cable 32a, once penetrated inside the volume 104, no longer emerges from the volume 104 indicates that there is a single continuous part 32a-2 of the radiating part of the cable 32a associated with this mobile assembly. The continuous part 32a-2 first travels along the inner side of the tire 12 relative to the vehicle, describing part of a first circle centered on the natural axis of rotation 102 of the mobile assembly. Then, after a bend in this cable 32a, it moves to the other side of the median plane 101 of the mobile assembly, in the direction Y of the vehicle, i.e. on the outer side of the tire 12 and of the vehicle. Finally, it partly describes a second circle still centered on the axis of rotation. natural 102 of the mobile assembly before the cable terminates on a termination present in the volume 104 in this specific case. This termination could be located outside the volume delimited by the cylinder 104.

[0112] The first circle described by the continuous part 32a-2 is located axially outside the mobile assembly. Here, the first circle has a radius less than the maximum radius of the mobile assembly, it could be greater. On this arc of a circle described by the continuous part 32a-2 of the communication cable, there is a meander 501, visible in Fig. 6c, extending perpendicular to the arc of a circle, that is to say radially in the reference frame of the mobile assembly. The surface delimited by the meander extends radially inside the first circle so that it intercepts the loop 601-2 described by the movement of the radiofrequency transponder present on the inner side of the tire 12. This loop is shown by a dotted circle in Fig. 6c.For an RFID radio tag operating at the UHF frequency of 920 MHz, the length of the RFID radio tag's radio frequency antenna is of the order of 5 centimeters when the RFID radio tag is buried in the structure of the tire. Generally, this radio tag is oriented mainly circumferentially. The meander 501 has a distance separating the forward strand and the return strand here of approximately 8 centimeters, which allows for better radio frequency communication between the meander 501 and the RFID radio tag antenna since the entire radiating antenna of the radio tag is located in the enhanced electric field generated by the input and output ends of the meander at a given time.

[0113] The second circle described by the continuous portion 32a-2 of the communication cable 32a is located radially outside the tire 12 relative to the axis of rotation 102. In the example illustrated in Figures 6 of this mobile assembly, the cable 32a on the outer side of the vehicle is mainly located axially outside the tire 12 with the exception of the meander 500-2 extending axially inward relative to the tire 12. Indeed, the meander 500-1 is then located axially outside the tire 12 as illustrated in Fig. 6a and Fig. 6b. However, the loop 601-1 described by the pseudo-periodic movement of the radiofrequency transponder of the tire is located axially close to the second circle of the communication cable 32a, which optimizes radiofrequency communication between the two antennas. The meander 500-2 would here make it possible to interrogate another radiofrequency transponder mounted on a mobile assembly having a width, in the axial direction, smaller or located at the right of the top of the tire 12, this top radially covering the outside of the tire 12. Here, the meanders 500-1 and 500-2 are not contiguous since the exit end of the meander 500-1 does not coincide with the entry end of the meander 500-2. However, they remain close, making it possible to create two zones of improved communication which are nevertheless distinct. In the case of contiguous meanders, in the shape of an “S” for example, the two meanders would form a single and unique zone of improved communication. Here, the curvilinear length of meanders 500-1 and 500-2 is of the order of 15 centimeters and the spacing P between the entry and exit ends of each meander is of the order of 4 centimeters.On the other hand, meander 501, although having a curvilinear length of 14 centimeters, has a spacing P of the order of 6 centimeters.

[0114] Such a continuous portion 32a-2 of the radiating portion of the communication cable 32a, fixed integrally to the transport vehicle and in particular to the surfaces delimiting the receiving cavity of the mobile assembly, makes it possible to communicate by radio waves with radiofrequency transponders mounted on the mobile assembly, in particular the pneumatic tire 12. This radiofrequency communication remains operational whether the radiofrequency transponders are located on one or the other of the sides of the pneumatic tire 12 and what is more whatever the dimension, in particular the width, of the mobile assembly equipping the transport vehicle. However, this configuration is not necessarily unique for achieving this radiofrequency communication objective; it is an illustrative example.

[0115] Fig. 7 is an example of a meander 500 on the continuous part of the radiating part of a bidirectional communication cable. This meander 500 is defined in an orthonormal plane UV associated with the meander. The axis U defined by the tangent of the bidirectional communication cable located just upstream and / or downstream of the meander 500, if these two directions are not parallel the median direction will be taken. The meander 500 is presented by an outward 511 and a return 512 which are connected to each other by a segment 513 at their second end. The first end of the outward 511, respectively of the return 512, is connected to the bidirectional communication cable located downstream or upstream of the meander 500. The change of direction between, on the one hand, the bidirectional communication cable and, on the other hand, the outward 511 or the return 513 of the meander 500 is made possible by the flexible nature of the communication cable which allows a more or less pronounced curvature of the communication cable. Naturally, we find this same change of direction between, on the one hand, the outward 511, or the return 512, of the meander 500 and the segment 513. The flexibility of the cable also allows this change of direction via the curvature potential of the communication cable.

[0116] This meander 500 is defined on the one hand by the average spacing or the average width between the outward journey 51 and the return journey 512 named “1” and the length L of the meander 500. The length “L” of the outward journey 511, or of the return journey 512, of the meander 500 is defined as the distance in the direction V, perpendicular to the direction U of the bidirectional communication cable, between the starting point 521 of the outward journey 511, respectively the arrival point 522 of the return journey 512, and the second end 523 of the outward journey 511, respectively the second end 524 of the return journey 512. This second end 523 or 524 is determined by two conditions. The first condition is that it is the largest coordinate along the V direction of a point of the communication cable 32 from the first end 521 of the outward journey 511, respectively the first end 522 of the return journey 512. Note that the origin of the V axis is defined at point 521, respectively 522.The second condition is that the tangent from the point of the communication cable 32 to this second end 523 or 524 has its largest component carried by the direction V. Finally, the segment 513 is delimited by the second ends 523 and 524 of the outward 511 and the return 512.

[0117] Finally, the average spacing “1” of the meander is determined by taking the distance in the direction U between the outward journey 511 and the return journey 512. The position in the direction U of the outward journey 511, respectively of the return journey 512, corresponds to the average value UA, respectively UB, of the coordinates of the points of the outward journey 511, respectively of the return journey 512, in the direction U by having a homogeneous distribution of the points along the cable 32. The outward journey 511 is delimited by the points 521 and 523 while the return journey 512 is delimited by the points 522 and 524. The points 521 and 522 are respectively the starting point and the arrival point of the meander 500. Each of the points 521 and 522 corresponds to the change in curvature of the cable relative to the direction of the cable located downstream, respectively upstream, of the meander 500, i.e. the direction of the vector U.

[0118] And the curvilinear length of the meander 500 is defined as the distance, along the bidirectional communication cable between the input end 525 and the output end 526 of the meander 500. Each of the points 525 or 526 is determined by the following condition. This is the point of the communication cable, starting from the starting point 521, respectively from the arrival point 522, whose tangent has its largest component carried by the direction V.

[0119] The curvilinear length of the cable must be between 0.9 and 1.1 times the half-wavelength L0 associated with the communication frequency of the reader system. In the case of communication at the frequency F0 of 900 MHz, the half-wavelength is then approximately 15 centimeters, the curvilinear length of the meander 500 must then be between 13.5 and 16.6 centimeters.

[0120] Finally, the distance "P" corresponds to the spacing between points 525 and 526 of the bidirectional communication cable. These two points 525 and 526 define the straight line D, the distance D corresponds to the length of the segment between the material points 525 and 526. Necessarily, the straight line D is substantially parallel to the axis U. In the case of communication at the frequency F0 of 900 MHz, the half-wavelength is then approximately 15 centimeters, the distance "P" must be less than a quarter of the wavelength, or 7.5 cm.

Claims

CLAIMS 1. Transport vehicle (2) comprising a system (3) for reading radiofrequency transponders and at least one mobile assembly (1) capable of ensuring the movement of the transport vehicle relative to the ground (600) on which the transport vehicle (2) is running, comprising a pneumatic tire (12) set in motion around an axis of rotation (102), the free movement of the at least one mobile assembly (1) taking place in a predominantly two-dimensional plane in a cylindrical frame of reference associated with the at least one mobile assembly whose axial direction is the direction of rotation axis (102), the pneumatic tire (12) defining a median plane (101) which is perpendicular to the rotation axis (102), the at least one mobile assembly (1), preferably the pneumatic tire (12), being equipped with a radiofrequency transponder (100,lOObis) the reading system (3) comprising: o An electrical signal generator (31) emitting at a frequency F0 included in the Ultra High Frequency band, coupled to a demodulator (31) of electrical signals adapted to a frequency band around F0, mounted on the transport vehicle; o At least one bidirectional communication cable (32), being partly flexible, comprising a conductive core (314) covered with a first dielectric element, itself covered with a conductive assembly (316), having one end (318) galvanically connected to the reading system (3), having at its free end (322) a means of capacitive coupling between the conductive core (314) and the conductive assembly (316) via a second dielectric element,adapted to the frequency band of the reading system (3); o The at least one bidirectional communication cable (32) being fixed securely to the transport vehicle (2) and externally to the at least one mobile assembly (1), comprising a radiating part (342), Characterized in that the distance of the radial projection of a first continuous part (32a-l, 32b-l) of the radiating part (342) of the at least one cable (32) on a cylinder (104), with an axis of revolution coaxial with the axis of rotation (102), circumscribed to the bandage pneumatic tire (12) is less than or equal to 1 meter, preferably less than or equal to 0.5 meters, in that the distance of the axial projection, in the direction of the axis of rotation (102), of the first continuous part (32a-l, 32b- 1 ) of the radiating part (342) of the at least one cable (32) on the median plane (101) of the pneumatic tire (12) is less than 2 meters, preferably less than or equal to 1 meter, very preferably less than or equal to 0.5 meters, in that the first continuous part (32a-l, 32b-l) of the radiating part (342) of the at least one cable (32) comprises at least one meander (500, 500-1, 500-2, 501), in that the curvilinear length of the at least one meander is between 0.9 and 1.1 times the half-wavelength L0 defined by the communication frequency F0 modulo the wavelength L0 and in that the distance “P” separating the two ends (525, 526) of the at least one meander (500, 500-1, 500-2, 501) is less than a quarter of the wavelength L0.

2. Transport vehicle (2) according to claim 1 wherein the radiating part (342) of the at least one cable (32) comprising at least one second continuous part (32a- 2, 32b-2) disjointed from the first continuous part (32a-l, 32b-l), the distance of the radial projection of the at least one second continuous part (32a-2, 32b-2) of the radiating part (342) of the at least one cable (32) on a cylinder, with an axis of revolution coaxial with the axis of rotation (102) of the at least one second mobile assembly (1), circumscribed to the pneumatic tire (12) of the at least one second mobile assembly (1) is less than or equal to 1 meter, preferably less than 0.5 meters and the distance of the axial projection, in the direction of the axis of rotation (102) of the at least one second mobile assembly (1), of the at least one second continuous part (32a-2, 32b-2) of the radiating part of the at least one cable on the median plane (101) of the pneumatic tire (12) of the at least one second mobile assembly (1) is less than 2 meters, preferably less than 1 meter, very preferably less than 0.5 meters.

3. Transport vehicle (2) according to claim 2 wherein, the at least one second continuous part (32a-2), 32b-2) of the radiating part (342) of the at least one cable (32) comprises at least one meander (500, 500-1, 500-2, 501), the curvilinear length of the at least one meander of the at least one second part is between 0.9 and 1.1 times the half-wavelength LO defined by the communication frequency FO modulo the wavelength LO, the distance “P” between the two ends (525, 526) of the at least one meander (500, 500-1, 500-2, 501) of the at least one second part is less than a quarter of the wavelength L0.

4. Transport vehicle (2) according to one of claims 1 to 3 wherein the radiating part (342) of the at least one cable (32) comprises at most 7 meanders (500, 501), preferably at most 5 meanders, (500-1, 500-2, 501).

5. Transport vehicle (2) according to one of claims 1 to 4 wherein, the radiofrequency transponder (100, 100bis) associated with the at least one mobile assembly (1) comprising a radiofrequency antenna comprising at least one wire strand defining a first longitudinal axis, each meander of the first (32a-1, 32b-1) and / or the at least one second (32a-2, 32b-2) continuous part of the radiating part of the at least one cable (32) defining a straight line D defined by the two ends (521, 522) of the at least one meander (500, 500-1, 500-2, 501), the angle formed by the direction vectors of the first longitudinal axis and of the straight line D is less than + / - 30 degrees, preferably less than + / - 20 degrees over at least part of the closed path described by the at least one mobile assembly (1).

6. Transport vehicle (2) according to claim 5 wherein, the at least one mobile assembly (1) being capable of describing a rotational movement around a single axis of rotation (102) defining a cylindrical reference frame around this axis of rotation (102), the first longitudinal axis of the radiofrequency antenna of the radiofrequency transponder (100, 100bis) associated with the at least one mobile assembly (1) having its main component oriented circumferentially in the cylindrical reference frame, the at least one meander (500-1, 500-2) associated with the first (32a-1, 32b-1) and / or the at least one second continuous part (32a-2, 32b-2) of the radiating part (342) of the at least one cable (32) being arranged radially externally to the mobile assembly (1) relative to the axis of rotation (102), the straight line D of the at least one meander has its principal component oriented circumferentially in the cylindrical frame of reference of the moving assembly (1).

7. Transport vehicle (2) according to claim 6 wherein, the radiofrequency antenna of the radiofrequency transponder (100, 100bis) associated with the at least one mobile assembly (1) and the at least one meander (500-1) associated with the first and / or the at least one second continuous part of the radiating part of the cable projecting in the same circumferential plane, the projection of the antenna of the radiofrequency transponder intersects at least the projection of the line D of the at least one meander.

8. Transport vehicle (2) according to claim 5 wherein, the mobile assembly (1) being capable of describing a rotational movement around a single axis of rotation (102) defining a cylindrical reference frame around this axis of rotation (102), the first longitudinal axis of the radiofrequency antenna of the radiofrequency transponder (100, 100bis) associated with the at least one mobile assembly (1) having its main component oriented circumferentially in the cylindrical reference frame, the at least one meander (501) associated with the first and / or the at least one second continuous part of the radiating part of the cable being arranged axially externally and radially internally to the mobile assembly (1) relative to the axis of rotation (102), the straight line D of the at least one meander has its main component oriented circumferentially in the cylindrical reference frame of the mobile assembly (1).

9. Transport vehicle (2) according to claim 8 wherein, the radiofrequency antenna of the radiofrequency transponder (100, 100bis) associated with the at least one mobile assembly (1) and the at least one meander (501) associated with the first and / or the at least one second continuous part of the radiating part of the cable projecting in the same axial plane, the projection of the antenna of the radiofrequency transponder intersects at least the projection of the line D of the at least one meander.

10. Transport vehicle (2) according to one of claims 1 to 9 in which the radiofrequency transponder comprises an RFID tag (100).

11. Transport vehicle (2) according to one of claims 1 to 10 wherein, the mobile assembly being capable of describing a rotational movement around an axis of rotation (102), each continuous part of the at least one cable describes an angular sector around the axis of rotation (102) at least greater than 30 degrees, preferably greater than 60 degrees, very preferably greater than 120 degrees.

12. Transport vehicle (2) according to one of claims 1 to 11 wherein the continuous part of the radiating part of the at least one cable is fixed on the at least one wall delimiting the cavity (21a-l, 21a-2, 2 lb-1, 21b-2) of the transport vehicle (2) accommodating the mobile assembly (1).

13. Transport vehicle (2) according to one of claims 11 to 12 wherein the first (32a-l, 32b-l) and / or the at least one second (32a-2, 32b-2) continuous part of the radiating part of the at least one cable extends at a constant radial distance from the axis of rotation (102) of the mobile assembly.

14. Transport vehicle (2) according to one of claims 1 to 13 in which the radiofrequency transponder (100, 100bis) transmits by a subcarrier frequency.

15. Transport vehicle (2) according to claim 14 in which the subcarrier frequency of the radiofrequency transponder comprises a number of transitions less than 5, preferably a single transition over the unit period of the subcarrier frequency.

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