Method and system for locating rolling mounted assemblies of a vehicle

Abstract

Disclosed is a method for locating rolling mounted assemblies (40a-1, 40a-2, 40b-1, 40b-2) of a vehicle (2), the vehicle comprising a device (33) sensitive to steering-wheel angle, comprising the following steps: - a phase of detection for a defined length of time while the vehicle is rolling, during which phase at least two values delivered by the device (33) and corresponding to two distinct steering-wheel angles are determined, - a phase of analysis comprising, for each received signal: determining the unique identifier encoded in the signal and at least one quantity of the signal, and for each identifier and for each of the two values, determining a set of quantities; and, depending on an evaluation of the dispersion of the quantities, deducing whether the identifier corresponds to a mounted assembly located on a steered or non-steered axle.

Description

DESCRIPTION Method and system for locating the rolling mounted assemblies of a vehicle TECHNICAL FIELD

[0001] The present invention relates to the detection and localization of rolling mounted assemblies equipped with radio frequency transponders, on a motor vehicle.

[0002] The recent development of connected objects requires equipping them with radio frequency transponders. Generally, these radio frequency transponders operate in the UHF (Ultra High Frequency) frequency range, i.e., between 300 MHz and 3 GHz, in order to have an effective compromise between the communication speed and the spatial footprint of the embedded communication system.

[0003] In the case of transport vehicles such as pneumatic tire vehicles, connected objects can be mobile components of these transport vehicles such as pneumatic tires but also fixed connected objects in the vehicle.

[0004] It is therefore important for a vehicle's central system to be aware of the various connected devices on board the vehicle, including mobile connected devices. The objective may be simply to identify them or to be able to communicate with them.

[0005] Patent applications DE19518806A1 or US20210021015A1 describe embedded systems that can communicate with connected objects installed on vehicle mounting assemblies by means of antennas, with a separate antenna associated with each mounting assembly.

[0006] These solutions therefore require the use of multiple radio frequency antennas, which are generally two-dimensional and flat, or even three-dimensional. This creates a space clutter within the vehicle that hinders the placement of other components. Furthermore, separating the various elements (radio frequency reader, transmission line, radio frequency antenna, etc.) multiplies the connection points between them, increasing the risk of system failure due to the vibrations and shocks that vehicles typically experience. Finally, the sheer number of assemblies in a land vehicle results in a greater number of transmission lines and radio frequency antennas, which is costly.

[0007] Document W02023 / 007079A1 describes a vehicle equipped with a radio frequency transponder reading device for mounted units, where the same radio frequency antenna receives signals from multiple transponders. This proposal allows for a drastic reduction in the number of components on the vehicle by sharing a significant portion of them.

[0008] While it is possible to inventory the radio frequency transponders associated with the vehicle's rolling stock assemblies, it is not easy to determine the location of each radio frequency transponder on the vehicle and in particular to distinguish those located at the front and rear of the vehicle, which amounts to knowing the location of the assemblies mounted on the steering or non-steering axle of the vehicle. DESCRIPTION OF THE INVENTION

[0009] The invention aims to improve the state of the art. In particular, a method and a system are proposed for locating the mounted assemblies of a vehicle by distinguishing whether they are on a steering axle or a non-steering axle.

[0010] Such a distinction makes it possible to know whether a detected mounted assembly is at the front or rear of the vehicle.

[0011] More specifically, a method for locating the rolling vehicle assemblies is proposed, each assembly comprising at least one radio frequency transponder communicating by backscattering and comprising at least one unique identifier in a memory space, the vehicle comprising a device sensitive to the steering wheel angle and a radio communication system galvanically coupled to at least one radio frequency antenna, said at least one radio frequency antenna covering in radio frequency communication at least one spatial area of ​​the vehicle included in a cavity in which are located the assemblies situated on the same side of the vehicle with respect to an axial plane of the vehicle, comprising the following steps: a detection phase during a defined duration of a vehicle movement during which at least two values ​​provided by said device and corresponding to two distinct steering wheel angles are determined,said detection phase comprising the following steps: radio frequency interrogations of at least said memory space of radio frequency transponders (communicating by backscattering); reception, via said at least one radio frequency antenna, of electrical signals representative of responses from said radio frequency transponders; a subsequent analysis phase following the detection phase, comprising the following steps: For each received signal, determination of the unique identifier encoded in said electrical signal, and of at least one quantity of the electrical signal; for each unique identifier encoded and for each of the at least two determined values ​​of the device, determination of a set of quantities of the corresponding electrical signal; and, based on an evaluation of the dispersion of said quantities in said set by comparison between quantities corresponding to each of said at least two values ​​provided by said device, deduce whether said unique identifier encoded corresponds to a mounted assembly located on a steering or non-steering axle of said vehicle

[0012] According to preferred embodiments, the invention comprises one or more of the following features which can be used separately or in partial combination with each other or in total combination with each other: said quantity of the electrical signal is based on a measurand included in a group comprising an amplitude of the electrical signal, a phase of the electrical signal relative to a signal emitted by said at least one radio frequency antenna; said dispersion is evaluated according to a metric included in a group comprising a mean value, a median value, a standard deviation and a variance; said duration corresponds to driving under iso-weather conditions; said steering wheel angle sensitive device is included in a group comprising a steering wheel angle sensor, an accelerometer according to the transverse direction of said vehicle, a pitch angle sensor of said vehicle, a wheel steering angle sensor, an output signal from a stability control device of said vehicle, a GPS system; during said period, driving is carried out at a speed of less than 100 km / h, preferably less than 50 km / h and very preferably less than 20 km / h; during the said period, the driving is carried out at a substantially constant speed, that is to say within a range of speeds of plus or minus 10km / h around said speed; said at least one unique identifier includes an SGTIN identifier associated with a component of a respective assembled assembly; said detection phase includes at least a first sub-phase corresponding to values ​​provided by said device corresponding to a first flywheel angle range, preferably around 0, and a second sub-phase corresponding to values ​​provided by said device corresponding to a second flywheel angle range located above a threshold value, and preferably below a second threshold value; said first and second sub-phases have a duration of at least one second.

[0013] Another object relates to a vehicle mounting system for locating rolling stock assemblies, capable of being associated with a vehicle, each mounting assembly comprising at least one radio frequency transponder communicating via backscattering, including at least one unique identifier in a memory space, the system comprising: a radio communication transmitter / receiver system, at least one radio frequency antenna galvanically coupled to the radio communication transmitter / receiver system, said at least one radio frequency antenna capable of covering in communication at least one spatial area of ​​the vehicle included in a cavity in which are located the mounted assemblies situated on the same side of the vehicle with respect to an axial plane of the vehicle, capable of emitting radio waves from the electrical signals at the output of the transmitter / receiver system and capable of receiving radio waves to convert them into a received electrical signal, at least one device capable of providing values ​​sensitive to the steering wheel angle of said vehicle; a processing device comprising at least one microprocessor and a memory space, capable of dividing said electrical signal into electrical signals representative of responses from said radio frequency transponders, and of implementing an analysis phase comprising: for each received signal, determination of the unique identifier encoded in said electrical signal, and of at least one quantity of the electrical signal; for each unique coded identifier and for each of at least two values ​​of the device, determination of a set of quantities of the corresponding electrical signal; and, based on an evaluation of the dispersion of said quantities in said set by comparison between quantities corresponding to each of said at least two values ​​provided by said device, deduce whether said unique coded identifier corresponds to a set mounted located on a steering or non-steering axle of said vehicle.

[0014] According to one embodiment, said steering wheel angle sensitive device is included in a group comprising a steering wheel angle sensor, a lateral-direction accelerometer, a pitch angle sensor, a wheel steering angle sensor, an output signal from a vehicle stability control device, and a GPS system.

[0015] Another item concerns a vehicle equipped with a location system as previously described.

[0016] Thus, although a single radio frequency antenna is intended to cover one side of the vehicle in communication, i.e. at least two mounted assemblies, it is made possible to distinguish the detected assemblies which are mounted on a steering axle and those which are mounted on a non-steering axle.

[0017] This process and system therefore allow the acquisition of important additional information to locate and identify radio frequency transponders associated with mobile connected objects in the vehicle.

[0018] In particular, they make it possible to solve the problem of locating connected and moving vehicle assemblies among the vehicle's assemblies on demand, especially in real time while the vehicle is moving.

[0019] Their location helps to enhance vehicle safety by ensuring the correct vehicle configuration in relation to the manufacturer's recommendations, thus allowing the vehicle to reach its full potential.

[0020] For example, it may be detected that a type of tire designed for a non-steering axle has been fitted to a steering axle. This detection may trigger an alarm for the driver or other automatic behaviors aimed at ensuring the safety of the vehicle and its passengers.

[0021] As another example, replacing the original tires with a spare can result in different vehicle safety behaviors depending on whether the axle is steerable or not. It may be advisable to limit the vehicle's speed or the power output of the powertrain to ensure the safety of the vehicle and its passengers. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other aspects, objectives, advantages, and features of the invention will become clearer upon reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the accompanying drawings in which: Figure 1 represents a simplified, cavalier perspective view of an example of a motor vehicle, according to one embodiment, Figure 2 represents an example of an assembly mounted according to an embodiment, Figure 3 schematically represents an embodiment of a radiocommunication system, Figures 4a and 4b represent two examples of situations of assemblies mounted in relation to a vehicle, according to an embodiment. Figures 5a and 5b represent examples of measurements of two quantities of the electrical signal as a function of the axles and the steering wheel angles. DETAILED DESCRIPTION OF SPECIFIC METHODS OF IMPLEMENTATION

[0023] The method and system presented are applicable to any type of land vehicle with at least one steering axle and one non-steering axle. They are particularly applicable to cars with a single steering axle and a single non-steering axle, but can also be applied to trucks with more than two axles. They can also be applied to self-guided vehicles or ground drones.

[0024] Figure 1 illustrates a simplified, cavalier perspective view of an example of an automobile-type vehicle.

[0025] In this illustrative example, the motor vehicle 2 is represented by a transparent volume depicting the closed, fitted body. For clarity, the axles and powertrain have been removed.

[0026] Vehicle 2 has cavities 21a-l, 21a-2, 21b-l, 21b-2 designed to accommodate each one mounted assembly.

[0027] Figure 2 illustrates an example of a mounted assembly adapted to be inserted into such a cavity.

[0028] The 40a-l assembly is particularly suitable for insertion into the respective cavity 20a-l. 40a-2, 40b-l, and 40b-2 assemblies, suitable for insertion into the respective cavities 20a-2, 20b-l, and 20b-2, may be identical or similar to the assembly shown in Figure 2.

[0029] This assembled unit, or wheel, 40a-l includes a pneumatic casing (or more simply, a tire) 42a-l and a rim 43a-l.

[0030] A radio frequency transponder device communicating via backscatter 41a-l is attached to this assembly. It can be positioned directly on or within the tire 42a-l. In particular, it can be embedded within the tire structure itself. It can also be positioned on the rim 43a-l.

[0031] The assembled unit may also include equipment such as a TPMS (for "Tire Pressure Monitoring System"), a TMS (for "Tire Mounted System"), etc.

[0032] Such a transponder could, for example, be an RFID tag according to the ISO 1800-6 standard.

[0033] Backscatter communication is a data transmission method that uses electromagnetic signals already present in the environment. Rather than generating its own signals, a backscatter device modulates and reflects existing signals to communicate information. These radio frequency transponders communicating via backscatter are associated with a center frequency, which must be known to the interrogating device (here, the transmitter / receiver system 311).

[0034] This technique is particularly advantageous because it does not require an external power supply to the radio frequency transponders, which can thus utilize the energy from the received waves. This is especially crucial given the difficulty of powering a device embedded in a mounted system.

[0035] An RFID tag (acronym for "Radio Frequency Identification") consists primarily of an electronic chip and an antenna. The chip contains the information to be transmitted, while the antenna enables communication with the RFID reader. Passive tags do not have their own power source and are activated by the signal from the RFID reader.

[0036] The 41a-l radio frequency transponder includes at least one unique identifier stored in a memory space of that transponder.

[0037] The energy of the signal received from a radio communication transmitter / receiver system (for example, an RFID reader) allows the radio frequency transponder chip to modulate this signal according to the data it wishes to transmit. It is expected here that the radio frequency transponder will respond to a query from the radio communication transmitter / receiver system with at least the stored unique identifier.

[0038] This unique identifier can, for example, be an identifier of the radio frequency transponder (in particular its chip) or an identifier of a component of the assembled unit 40a-l, for example its rim 43a-l or, preferably, its tire casing 42a-l. These component identifiers can be the serial numbers of these components.

[0039] In particular, a unique identifier can be an SGTIN identifier associated with a component of a respective assembled assembly.

[0040] The SGTIN (short for "Serialized Global Trade Item Number") combines a product's GTIN (Global Trade Item Number) with a unique serial number. The structure is: "EPC Header" (Electronic Product Code header): Indicates that this is an SGTIN and specifies the length of the other fields. "GSI Company Prefix": Identifies the company that manufactured or distributed the relevant component of the assembled assembly. “Item Reference”: Refers to the type of item (equivalent to GTIN or EAN barcode). “Serial Number” (serial number): A number to differentiate each item.

[0041] According to some embodiments, the memory space of the radio frequency transponder can contain several identifiers (for example a chip identifier and a tire identifier) ​​and other data in addition to this or these identifiers.

[0042] As illustrated in Figure 1, the vehicle also includes a location system 3 for the rolling assembly units of vehicle 2. This location system can also, more generally, enable communication with the radio frequency transponders installed on the assembly units.

[0043] The location system includes a radio communication system 31. This system may consist of one or more devices, each performing one or more functions as illustrated in Figure 3.

[0044] These devices, which make up the radio communication system 31, can be distributed throughout the vehicle or co-located, for example at the level of the firewall, which is a wall that is mainly vertical in relation to the floor of the vehicle and which delimits the engine compartment located at the front of the vehicle from the passenger compartment.

[0045] The radio communication system 31 includes, in particular, a radio communication transmitter / receiver system 311. This system can be designed to modulate and demodulate electrical signals. Specifically, it can convert digital signals into analog signals and vice versa. These analog signals represent electromagnetic waves emitted or received by means of antennas 32a, 32b galvanically connected to this transmitter / receiver system 311.

[0046] According to one embodiment, as mentioned previously, this transmitter / receiver system 311 can be an RFID reader. It is a device designed to read and interpret the data contained in RFID tags.

[0047] From this radio communication system 31, and more specifically from the transmitter / receiver system 311, two bidirectional communication cables 32a, 32b run respectively to the left and right sides of vehicle 2.

[0048] In what follows, the terms left and right allow us to distinguish the two sides of the vehicle according to the direction of forward movement. The separation between the right and left sides can be made based on an axial plane (for example, a median plane) 22 that divides the vehicle 2 into two parts. This axial plane 22 is perpendicular to the vehicle floor and coplanar with the direction of travel of the vehicle.

[0049] The communication cables are traveling wave cables and are mounted on the transmitter / receiver system 311 to form a galvanic link. Each cable runs through the structure of vehicle 2 to reach the vicinity of at least one cavity for mounting assemblies. Each cable includes signal transmission sections and radiating sections.

[0050] In fact, each cable 32a, 32b reaches the vicinity of two cavities for receiving the mounted assemblies, each corresponding to the front axle and the rear axle of vehicle 2.

[0051] At the level of the first cavity 21a-l, the cable 32a has at least one radiating portion 32a-l forming an antenna. This radiating portion can be continuous and describe an angular sector of 120 degrees around the axis of the front axle.

[0052] This radiating part is located at the intended passage of the element carrying the radio frequency transponder. In other words, the radio frequency antenna 32a-l covers, in communication, at least a spatial area of ​​the vehicle included within the cavity 21a-l intended to house a mounted assembly 40a-l.

[0053] Thus, as illustrated in Figure 2, the transmitter / receiver system 311 may be required to communicate with the transponder 41a-l when the latter is in the area covered by the radio frequency antenna 32a-l.

[0054] The same applies to the other cavities of the vehicle.

[0055] Thus, the same cable 32a also extends to a second receiving cavity 21a-2 located on the same left side of the vehicle. In the illustrated example, this cavity 21a-2 corresponds to the rear axle, while the first cavity 21a-1 corresponds to the front axle. Near this cavity, the cable 32a also has a radiating section, or radio frequency antenna, which provides communication coverage to a spatial area of ​​the vehicle contained within this cavity 21a-2.

[0056] This cavity 21a-2 is intended to receive a mounted assembly 40a-2. In this way, the transmitter / receiver system 311 can communicate with the transponder 41a-2 when the latter is in the area covered by the radio frequency antenna 32a-2.

[0057] The radiating antenna 32a-2 can be continuous and describe an angular sector of 90 degrees around the axis of the rear axle. This value may differ from that of the antenna 32a-l corresponding to the front axle because, in this example, it is assumed that the rear axle is not steerable. Consequently, the assembled unit moves very little angularly during vehicle movement. Furthermore, radio frequency communication between the radiating antenna 32a-2 and the bidirectional communication cable 32a is facilitated compared to that of the radiating antenna 32a-l corresponding to the steerable front axle, which generates angular movement of the assembled unit, for example, when turning.

[0058] These two radiating sections 32a-l, 32a-2 are shown here separated, but they could be joined. Each allows communication only with one respective radio frequency transponder 41a-l, 41a-2, of a mounted unit. However, in the case of a dual-wheel axle, such as in a utility vehicle in traction mode, the radiating section 32a-2 located near cavity 21a-2 can allow communication with the radio frequency transponders of the various dual mounted units located on the same axle and on the same side of the vehicle 2.

[0059] It therefore appears that the transmitter / receiver system 311 can receive an electrical signal on the cable 32a which can come from several radio frequency transponders, via the plurality of radiating parts 32a-1, 32a-2.

[0060] Similarly, the two-way communication cable 32b has two radiating sections 32b-l and 32b-2 corresponding to two cavities, respectively 21b-l and 21b-2, located on the right side of the vehicle. Since the arrangement on this right side can be completely symmetrical and identical to that on the left side, it will not be described in further detail here.

[0061] It is important to note that the transmitter / receiver system 311 can receive an electrical signal on the cable 32b which can come from several radio frequency transponders, via the plurality of radiating parts 32b-1, 32b-2.

[0062] The total length of the 32a, 32b communication cable may not exceed 5 meters, in particular thanks to the pooling provided by the fact that the same cable can include several radiating parts associated with several receiving cavities of mounted assemblies.

[0063] In one embodiment, the radiating portion forming the radio frequency antenna, 32a-l, 32a-2, 32b-l, 32b-2, can exceed 50 centimeters, which corresponds to one-quarter of the development of a tire 42a-l, 42a-2, 42b-1, 42b-2 in the case of a passenger vehicle. This length exceeds the cable length for UHF radio frequency communication at 920 MHz or 2.4 GHz. It is therefore compatible with RFID communication.

[0064] Also, the 311 transmitter / receiver system can determine whether a received signal originates from the left or right side of the vehicle by knowing which bidirectional communication cable, 32a, 32b, it comes from. The challenge then becomes determining whether the signal originates from a steering axle (usually the front) or a non-steering axle (usually the rear).

[0065] It is therefore planned that the location system 3 will include at least one device 33 capable of providing values ​​sensitive to the steering angle of the vehicle.

[0066] A value sensitive to steering wheel angle is a value that changes when the angle of rotation of the vehicle's steering wheel changes. In other words, this value is representative of the vehicle's heading and therefore of the rotation of the steering axles.

[0067] This value can, of course, be directly the steering wheel rotation angle of vehicle 2, which can be captured by an angular sensor located on the steering wheel itself. However, other types of devices can also be considered, such as an accelerometer measuring the vehicle's lateral direction, a vehicle pitch angle sensor, a wheel steering angle sensor, an output signal from a vehicle stability control system (or ESP, for "Electronic Stability Program"), a GPS (Global Positioning System), whose historical geographical position data allows for route planning, and so on. Other devices are also possible insofar as they can provide a value representative of the vehicle's change in direction.

[0068] The radio communication system 31 is designed to trigger a detection phase, followed by an analysis phase. These two phases work together to determine the location of the radio frequency transponders of the assemblies mounted on the steering and non-steering axles of the vehicle. As previously mentioned, the radio frequency transponders allow the respective mounted assemblies to be identified by means of their unique identifiers.

[0069] The detection phase is triggered for a defined duration of a vehicle journey.

[0070] This detection phase includes interrogations of radio frequency transponders, and receptions of electrical signals representative of the responses of these radio frequency transponders.

[0071] The duration of the detection phase can, for example, be a few seconds, but can extend over time intervals spread over a longer period of time.

[0072] This duration must be sufficient to allow for the collection of a sufficient number of responses from the radio frequency transponders. This number must be large enough to allow for an analysis of the dispersion of a measurement among these responses, as will be discussed later.

[0073] In addition, a large number can help mitigate the statistical risks associated with the quality and variability of measurements that can be made on these electrical signals representative of the responses.

[0074] Preferably, this driving is carried out under the same weather conditions for this defined duration.

[0075] It should be noted that weather conditions can substantially influence various parameters involved in the described process and system, particularly the quality of communication between the radio frequency transponders and the radio frequency antennas mounted on the vehicle. Variability in this quality due to weather changes would be superimposed on the variability related to the steering angle that we are trying to estimate. It could therefore impact the quality of the results obtained.

[0076] Also, according to one embodiment, the driving is carried out at a speed of less than 100 km / h, preferably less than 50 km / h, very preferably less than 20 km / h.

[0077] Indeed, excessive speeds can generate rolls or pitching motions that could also distort measurements and location estimates. These threshold values ​​may need to be adjusted depending on the type of vehicle and the evolution of suspension systems, among other factors.

[0078] It is also preferable that during the defined duration corresponding to the detection phase, driving takes place at a substantially constant speed, that is to say within a speed range of plus or minus 10km / h around this target speed.

[0079] In general, uniformity of driving conditions can be sought during the detection phase, with the exception of the steering angle: since the rental estimate is based on the variation of this parameter, it is indeed interesting to limit the variations of any other parameter during this detection phase in order to avoid any bias.

[0080] However, it is indeed important to have a substantial variation in the steering wheel angle during this detection phase.

[0081] In particular, at least two values ​​provided by device 33 must correspond to distinct flying angles.

[0082] Preferably, these distinct angles should be substantially apart, for example corresponding to different states of vehicle driving: driving in a straight line and driving in a continuous turn.

[0083] According to one embodiment, a first population of flying angles corresponds to a first interval preferably around 0°, for example less than 5°, and a second population corresponds to a second interval located above a threshold value, for example 120°, and preferably below another threshold value, for example 180°.

[0084] These intervals can correspond respectively to driving in a straight line (or substantially straight) and to a sharp, sustained turn. This type of turn could, for example, correspond to a roundabout.

[0085] To do this, the decoding device can trigger a first sub-phase to determine the first population, and a second sub-phase to determine the second population.

[0086] These sub-phases may not be entirely consecutive but may alternate depending on the driver's route: a straight stretch of road to generate all or part of the first population, while a sharp turn may generate all or part of the second population. If another straight stretch of road or another turn occurs, the respective populations may be enriched.

[0087] According to one embodiment, there are not two distinct populations but one population distributed over a wide distribution of flying angles, the important point being to have enough "points" corresponding to distant flying angles.

[0088] The radio communication system 31 can control this detection phase. According to one embodiment, it can control the detection phase by detecting opportune moments to trigger measures, for example by detecting straight road segments and curves held for a sufficient time.

[0089] For example, these detections can be predictive or reactive by monitoring the consistency of the value generated by device 33: It can detect the presence of a straight road segment by the absence of variation in the value from device 33 for a certain time. It is then likely that this segment continues and therefore that a detection phase must be triggered (first sub-phase). It can trigger a sub-phase (first or second) and abandon it if the conditions are not maintained long enough (exit from the straight road segment, exit from the maintained turn).

[0090] According to one embodiment, the first and second sub-phases have a duration of at least one second, which allows the acquisition of a sufficient number of measurement points to enable dispersion analysis and, possibly, statistical consolidation, as previously explained.

[0091] In one embodiment, the radio communication system 31 can also control the detection phase to comply with the constraints mentioned above, for example, maintaining a constant speed below a defined threshold and driving under identical weather conditions. If the radio communication system 31 detects that one or more of these constraints are no longer met, it can interrupt the detection phase and possibly restart it later.

[0092] This detection phase includes radio frequency interrogations of at least the memory space of radio frequency transponders 41a-l, 41a-2, 41b-l, 41b-2 containing the unique identifier.

[0093] The detection phase also includes the reception of electrical signals representative of responses from these radio frequency transponders.

[0094] Interrogations and receptions are carried out via radio frequency antennas 32a, 32b.

[0095] The 311 radio communication transmitter / receiver system can provide an electrical signal corresponding to the radio frequency behavior received by the antennas. This electrical signal includes all the electrical signals representative of the responses of the radio frequency transponders communicating in backscatter.

[0096] The radio communication system 31 also includes a processing device 312, 313, 314, 315, capable of processing the signals provided by the radio communication transmitter / receiver system 311.

[0097] A signal processing device 312 may be provided to cut (or isolate) this received electrical signal into at least one electrical signal representative of a response, or, in other words, into a coded response corresponding to a given radio frequency transponder.

[0098] It should be noted that radio frequency transponders generally have a variable latency period. Therefore, it is highly unlikely that the same interrogation will generate two responses from radio frequency transponders located on the same side of the vehicle (and thus received via the same communication cable 32a, 32b) within the same time interval. Consequently, in the vast majority of cases, it is possible to segment, or isolate, the responses within the received signal.

[0099] A device 313 can be used to control the detection phase, specifically to determine whether conditions trigger an analysis phase or if the detection phase should be maintained. This includes verifying that responses have been received from a sufficient number of different flying angles, as explained previously. To achieve this, the values ​​provided by device 33 can be recorded to verify in real time whether this stopping criterion is met.

[0100] The analysis phase can be triggered subsequently to the detection phase.

[0101] It includes a step, which can be implemented by device 314, of determining, for each received signal (i.e., for each response from a radio frequency transponder): the unique identifier encoded in this signal, and at least one magnitude of the electrical signal.

[0102] The radio communication system 31 can thus associate a received response with a given radio frequency transponder. Analysis of the electrical signal magnitude allows, statistically, the determination of the transponder's location between a steering axle and a non-steering axle.

[0103] The magnitude of the electrical signal is expected to be representative of a distance between the radio frequency transponder and the respective radiating part(s) of the two-way communication cable.

[0104] Figures 4a and 4b are top views of a vehicle 2 on which four mounted assemblies 40a-l, 40a-2, 40b-l, 40b2 each comprising a single radio frequency transponder, respectively 41a-l, 41a-2, 41b-l, 41b-2.

[0105] The two-way communication cables are also shown, each comprising two sets of radiating parts, respectively 32a-1, 32a-2 and 32b-1, 32b-2, represented by black rectangles on the cable.

[0106] In this example, therefore, the antennas are subdivided into two radiating parts in order to maximize radio frequency coverage, but obviously other embodiments are possible.

[0107] In figure 4a, the vehicle is traveling on a straight section of road. The mounted components are therefore aligned with the vehicle.

[0108] In figure 4b, the vehicle is making a turn. The mounted elements 40a-l, 40b-l, installed on the steering axle, have rotated according to the steering wheel angle.

[0109] This rotation of the mounted components generates a relative displacement of the radio frequency transponders with respect to the radio frequency antennas (which are fixed and attached to the vehicle). This relative displacement, in turn, generates a variation in the distance between the radio frequency transponder and the respective antenna.

[0110] This variation can be captured by the magnitude of the electrical signal designed for this purpose.

[0111] Figure 4b shows that the rotation of the front axle brings the radio frequency transponder 41b-l closer to the antenna 32b-l, while it moves the radio frequency transponder 41a-l further away from the antenna 32a-l.

[0112] Different types of electrical signal quantities can be considered.

[0113] Several measurands can be considered. For example, the magnitude of the electrical signal can be based on an amplitude of the electrical signal, a phase of the electrical signal relative to a signal emitted by the radio frequency antenna (for transponder interrogations), etc.

[0114] In general, the chosen quantity must vary when the angle of the steering axle varies.

[0115] As we have seen, the detection phase consisted of obtaining electrical signals for at least two distinct angles.

[0116] A device 315 can be provided to determine, for each unique identifier coded in the electrical signal, a set of quantities of the corresponding electrical signal.

[0117] Based on an assessment of the dispersion of quantities in this set, it can deduce whether the unique coded identifier corresponds to a mounted set located on a steering or non-steering axle of the vehicle.

[0118] In particular, this assessment of dispersion may consist of comparing these quantities for each of the at least two values ​​provided by the said device for these two distinct angles. These values ​​may fall within two intervals, each corresponding to one of these distinct angles.

[0119] Evaluating dispersion can involve comparing the quantities obtained in each of these intervals, and assessing differences between these two populations.

[0120] A dispersion metric (e.g., comparison of the mean of the magnitudes in each interval, the median, etc.) allows a comparison between the two populations of magnitudes corresponding to two angle values.

[0121] On a steering axle, a change in the metric is observed, indicating that it is a steering axle. Conversely, on a non-steering axle, the dispersion metric is substantially constant regardless of the angle value.

[0122] More specifically, if there is a dispersion then the unique coded identifier corresponds to a mounted assembly located on a steering axle.

[0123] If there is no dispersion, then the unique coded identifier corresponds to a mounted assembly located on a non-steering axle.

[0124] The evaluation of the dispersion of the measured quantity on electrical signals containing a unique identifier of a given mounted assembly forms a criterion for differentiation between mounted assemblies installed on a steering or non-steering axle.

[0125] Dispersion can be assessed in various ways. For example, it can be based on a metric such as a mean, median, standard deviation, and / or variance. Any other estimator of the dispersion of a statistical population can obviously be used.

[0126] The presence and absence of dispersion can be determined by comparing this assessment of dispersion against a threshold.

[0127] Also, we can compare the dispersion assessments for the two populations, and compare (for example) their difference or their ratio relative to a threshold.

[0128] The threshold can be arbitrarily set; its purpose is to ensure that we obtain two populations corresponding to different dispersions. It can, in principle, be as small as desired, but greater than zero.

[0129] It is therefore observed that the radio frequency transponders of the mounted assemblies installed on a steering axle experience a significant variation in their distance from the antennas. This variation in distance is reflected in a variation in the magnitude of the electrical signal from the corresponding antenna. It is therefore possible to detect that a mounted assembly is installed on a steering axle by studying the variation in the magnitude associated with the electrical signals that contain the unique identifier of that mounted assembly.

[0130] Conversely, a mounted assembly installed on a non-steering axle does not generate any variability in the measured quantity on the electrical signal containing a unique identifier corresponding to that mounted assembly.

[0131] We can therefore locate an assembly mounted on a steering axle or on a non-steering axle.

[0132] In most cases, there is only one steering axle and one non-steering axle, which allows for complete localization.

[0133] In most cases, it is only important to know whether a mounted assembly is installed on a sensing axle or a non-sensing axle.

[0134] An example was given of checking the installation of a suitable assembly on a type of axle, with certain types of assembly being more particularly suited for steering axles.

[0135] Figures 5a and 5b represent examples of measurements of two quantities of the electrical signal as a function of the axles and the steering wheel angles.

[0136] Figure 5a shows measurements of a phase quantity of the electrical signal (in degrees) for a front steering axle, AV, and a rear non-steering axle, AR. For each axle, the values ​​of the steering wheel angle-sensitive device 33 allow the construction of 3 populations corresponding to a straight line (PR,L and PAV,L), a right turn (PAR,D and PAV,D) and a left turn (PAR,G and PAV,G).

[0137] For the non-steering AR axle, we note that the three populations PAR,L, PAR,D and PAR,G are "grouped" around a phase magnitude of approximately 160-170°, while the three populations PAV,L, PAV,D and PAV,G are dispersed over a substantially wider range of magnitudes, between 125° and 225° (considering an average metric for each population).

[0138] In other words, an evaluation of the dispersion makes it possible to locate assemblies mounted rolling on a steering or non-steering axle by comparing quantities corresponding to the populations associated with the values ​​provided by the device 33 sensitive to the steering wheel angle.

[0139] Figure 5b represents measurements of an electrical signal power quantity (in nanowatts) for a front steering axle, AV, and a rear non-steering axle, AR.

[0140] For each axle, the values ​​of the device 33 sensitive to the steering wheel angle allow us to construct 3 populations corresponding to a straight line (P'AR,L and P'VL), a right turn (P'RD and P'VD) and a left turn (P'RG and P'AV,G).

[0141] For the non-steering axle AR, we note that the three populations P' RL, P' RD and P' RG are "grouped" around a power magnitude of approximately 1400-1500 nW, while the three populations P' VL, P'Av.oet P' VG are dispersed over a substantially wider range of magnitudes, between approximately 1200 and 2000 nW (considering an average metric for each population).

[0142] In this example as well, the comparison of the quantities corresponding to the populations associated with the values ​​provided by the device 33 sensitive to the steering wheel angle makes it possible to deduce whether a mounted assembly is located on a steering or non-steering axle of said vehicle.

[0143] Of course, the present invention is not limited to the examples and embodiment described and illustrated, but is defined by the claims. In particular, it is susceptible of numerous variations accessible to those skilled in the art.

Claims

DEMANDS 1. A method for locating the rolling vehicle assemblies (40a-l, 40a-2, 40b-l, 40b-2) of a vehicle (2), each assembly comprising at least one radio frequency transponder (41a-l, 41a-2, 41b-l, 41b-2) communicating by backscattering and comprising at least one unique identifier in a memory space, the vehicle comprising a steering wheel angle-sensitive device (33) and a radio communication system (31) galvanically coupled to at least one radio frequency antenna (32a, 32b), said at least one radio frequency antenna covering in radio frequency communication at least one spatial area of ​​the vehicle included in a cavity (21a-l, 21a-2, 21b-l, 21b-2) in which are located the assemblies situated on the same side of the vehicle with respect to an axial plane (22) of the vehicle, comprising the steps following: a detection phase during a defined period of vehicle movement during which at least two values ​​provided by said device (33) are determined, corresponding to two distinct steering wheel angles, said detection phase comprising the following steps: radio frequency interrogations of at least said memory space of the radio frequency transponders; reception, via said at least one radio frequency antenna, of electrical signals representative of responses from said radio frequency transponders; a subsequent analysis phase following the detection phase, comprising the following steps: for each received signal, determination of the unique identifier coded in said electrical signal, and of at least one quantity of the electrical signal; for each unique coded identifier and for each of the at least two determined values ​​of the device, determination of a set of quantities of the corresponding electrical signal; and, based on an evaluation of the dispersion of said quantities in said set by comparison between quantities corresponding to each of said at least two values ​​provided by said device, deduce whether said unique coded identifier corresponds to a mounted set located on a steering or non-steering axle of said vehicle.

2. Method for locating the rolling assembly units of a vehicle according to claim 1, wherein said quantity of the electrical signal is based on a measurand included in a group comprising an amplitude of the electrical signal, a phase of the electrical signal relative to a signal emitted by said at least one radio frequency antenna.

3. Method for locating the rolling mounted assemblies of a vehicle according to one of claims 1 or 2, wherein said dispersion is evaluated according to a metric included in a group comprising a mean value, a median value, a standard deviation and a variance.

4. Method for locating the rolling mounted assemblies of a vehicle according to any one of claims 1 to 3, wherein said duration (T) corresponds to a drive under iso-weather conditions.

5. Method for locating the rolling assembly units of a vehicle according to any one of the preceding claims, wherein said steering wheel angle-sensitive device is included in a group comprising a steering wheel angle sensor, an accelerometer in the transverse direction of said vehicle, a pitch angle sensor of said vehicle, a wheel steering angle sensor, an output signal from a stability control device of said vehicle, and a GPS system.

6. A method for locating the rolling assembly components of a vehicle according to any one of the preceding claims, wherein, during said time, the rolling is carried out at a speed of less than 100 km / h, preferably less than 50 km / h and very preferably less than 20 km / h.

7. A method for locating the rolling assembly components of a vehicle according to any one of the preceding claims, wherein, during said time, the rolling is carried out at a substantially constant speed, i.e. within a range of speeds of plus or minus 10 km / h around said speed.

8. Method for locating the rolling assembly units of a vehicle according to any one of the preceding claims, wherein said at least one unique identifier comprises an SGTIN identifier associated with a component of a respective assembly unit.

9. Method for locating the rolling mounted assemblies of a vehicle according to one of the preceding claims, wherein said detection phase comprises at least a first sub-phase corresponding to values ​​provided by said device corresponding to a first steering angle range, preferably around 0, and a second sub-phase corresponding to values ​​provided by said device corresponding to a second steering angle range located above a threshold value, and preferably below a second threshold value.

10. Method for locating the rolling mounted assemblies of a vehicle according to the preceding claim, wherein said first and second sub-phases have a duration of at least one second.

11. A vehicle mounting system (3) for localization of rolling stock assemblies, capable of being associated with a vehicle (2), each mounting assembly comprising at least one radio frequency transponder communicating by backscattering, comprising at least one unique identifier in a memory space, the system comprising: a radio communication transmitter / receiver system (311), at least one radio frequency antenna (32a, 32b) galvanically coupled to the radio communication transmitter / receiver system, said at least one radio frequency antenna capable of covering in communication at least one spatial area of ​​the vehicle included in a cavity (21a-l, 21a-2, 21b-l, 21b-2) in which are located the mounted assemblies situated on the same side of the vehicle with respect to an axial plane of the vehicle, capable of emitting radio waves from the electrical signals at the output of the transmitter / receiver system and capable of receiving radio waves to convert them into a received electrical signal, at least one device (33) capable of providing values ​​sensitive to the steering wheel angle of said vehicle; a processing device (312, 313, 314, 315) comprising at least one microprocessor and a memory space, capable of dividing said electrical signal into electrical signals representative of responses from said radio frequency transponders, and of implementing an analysis phase comprising: for each received signal, determination of the unique identifier coded in said electrical signal, and of at least one quantity of the electrical signal; for each unique coded identifier and for each of at least two values ​​of the device, determination of a set of quantities of the corresponding electrical signal; and, based on an evaluation of the dispersion of said quantities in said set by comparison between quantities corresponding to each of said at least two values ​​provided by said device, deduce whether said unique coded identifier corresponds to a mounted assembly located on a steering or non-steering axle of said vehicle.

12. A vehicle mounting system for localization according to the preceding claim, wherein said steering wheel angle-sensitive device is included in a group comprising a steering wheel angle sensor, a lateral accelerometer, a pitch angle sensor, a wheel steering angle sensor, an output signal from a vehicle stability control device, and a GPS system.

13. Vehicle (2) comprising a localization system (33) according to one of claims 11 or 12.

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