METHOD and system for identifying the rolling stock assemblies of a vehicle

Abstract

A method for identifying the rolling vehicle assemblies, each assembly comprising a radio frequency transponder with an identifier, the vehicle comprising a radio communication system coupled to a radio frequency antenna, the radio frequency antenna covering a spatial area of ​​the vehicle in which the assemblies are located, comprising the following phases: • Initiating a detection phase while the vehicle is in motion, comprising: Initiating an interrogation phase for a duration T; Receiving, for the duration T, radio waves backscattered by the radio frequency transponders; • Initiating an analysis phase comprising: Identifying the coded responses; Determining the unique identifier and a quantity of the electrical signal for each coded response; For several coded responses with the same unique identifier, evaluating each quantity against a reference;If at least one quantity is far from the reference threshold S, place the unique identifier in a specific list. Figure for the abbreviation: Fig. 2;

Description

Title of the invention: METHOD and system for identifying the rolling assembly components of a vehicle Scope of the invention

[0001] The present invention relates to the field of electronic devices, particularly those related to transport vehicles and especially those installed on the mounted assemblies of the transport vehicle. Technological background

[0002] The recent development of connected objects necessitates 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, for the most efficient compromise between communication speed and the spatial footprint of the communication system. In the case of transport vehicles, such as vehicles with pneumatic tires, connected objects can be mobile components of these vehicles, such as the tires themselves, but also fixed connected objects within the vehicle. Since radio communication is the most cost-effective technical solution for exchanging information with the radio frequency transponders of these multiple connected objects, it is sometimes necessary to be able to distinguish a group of connected objects from among all the connected objects in the vehicle.For example, identifying the tires mounted on rims at the various points on the vehicle becomes a challenge. Generally, communication with these transponders requires the use of transmitter / receiver devices equipped with radio frequency antennas capable of emitting or receiving electromagnetic waves to cover all or part of the vehicle. However, the vehicle may also include connected devices that are not part of the vehicle's rolling chassis. Communication initiated by the vehicle's transmitter / receiver devices is also potentially active with the radio frequency transponders of these non-rolling connected devices.

[0003] Document US20210021015A1 shows, in the case of a land vehicle, the implementation of an on-board RFID (Radio Frequency Identification) tag reading system and TMS (Tire Mounted Sensor) sensors located in the tire casings of the land vehicle's mounted assemblies. This system consists of a radio frequency reader / transmitter galvanically connected to four transmission lines up to Radio frequency antennas, each covering a specific geographic area, are permanently attached to the vehicle's fixed structure. However, radio communication between electronic devices is energy-intensive, particularly the radio frequency transmission phase compared to the radio frequency signal reception phase, or when communication between devices is bidirectional. Bidirectional communication requires one electronic device to be activated by the other through the transmission of specific information that informs the other device of the bidirectional communication setup.

[0004] One of the objects of the following invention aims to solve the problem of simply and reliably identifying the vehicle's connected and moving assemblies among the multitude of connected objects in and out of the vehicle, particularly on demand while the vehicle is in motion. Identifying these objects then allows for selectivity in the communication with which the vehicle needs to communicate for proper operation while driving, thus ensuring speed and efficiency of radio frequency communication by selecting the correct connected objects. Description of the invention

[0005] The invention relates to a method for identifying the rolling assembly units of a vehicle, each assembly unit comprising at least one radio frequency transponder communicating by backscattering and comprising at least one unique identifier in a memory space of the radio frequency transponder, the vehicle comprising a radio communication system, galvanically coupled to at least one radio frequency antenna, the at least one radio frequency antenna covering in radio frequency communication at least one spatial area of ​​the vehicle in which all the rolling assembly units of the vehicle are located, comprising the following phases: • Initiate a detection phase during vehicle movement, including the following steps: • Launch a radio frequency interrogation step of at least one memory space of the radio frequency transponders communicating in backscatter containing at least one unique identifier for a duration T; • To receive, via at least one radio frequency antenna, for a duration T, radio waves from radio frequency transponders communicating in backscattering; • Launch an analysis phase after the detection phase, including the following steps: • Identify, via an electrical signal processing device, the coded responses contained in the received radio waves; • Determine a unique identifier and at least one quantity of the received electrical signal for each coded response via a reading device; • For each unique identifier determined for at least two identified coded responses, evaluate each of at least one quantity against a reference; • If at least one quantity is far from the reference of a threshold S, place the unique identifier associated with these at least two coded responses in a specific list stored in a memory space, otherwise erase the determined unique identifier.

[0006] Advantageously, the magnitude of the received signal is included in the group comprising the amplitude of the received electrical signal and the phase of the received signal with respect to the generated electrical signal.

[0007] The term "assembly" here refers to all the components that can be rotated around an axis corresponding to one of the vehicle's axles. This may be a structural component such as the tire, wheel rim, valve, brake disc or drum, wheel hub, or any other component rotating around the axis of a vehicle axle during vehicle movement.

[0008] The method just described solves the technical problem for the following reasons. During the detection phase, which takes place while the vehicle is in motion, the method captures all responses from radio frequency transponders located in areas of interest relative to the target, namely the vehicle's mounted assemblies. Ideally, communication is achieved with all the vehicle's radio frequency transponders. However, it is certain that all radio frequency transponders belonging to a moving vehicle mounted assembly will be captured, provided that this mounted assembly has a radio frequency transponder and that it is operational. Furthermore, since radio communication is not spatially limited, it is possible to also capture radio frequency transponders located outside the target vehicle.This could be radio frequency transponders associated with connected devices in another vehicle or radio frequency transponders associated with connected devices located along the vehicle's route.

[0009] Next, in the analysis phase, which can be partially or fully performed while the vehicle is in motion, the electrical signals received by each radio frequency antenna are first separated into independent coded responses. This means that the coded responses do not overlap on the same received electrical signal. This is possible, in part, due to the interrogation protocols used. For example, by assigning each transmitted signal a random response time, the coded responses of the radio frequency transponders are randomly distributed over time. Furthermore, the coded response is formatted to distinguish it within the electrical signal, thus allowing the identification of at least the beginning of each coded response, and ideally the end of each coded response, making it possible to determine if a collision between the coded responses has occurred at the radio signal reception level.Such a collision then results in the elimination of the portion of the electrical signal located between the beginning of the first coded response and the end of the second coded response, the first and second responses having become intertwined.

[0010] For each identified coded response, a quantity of the electrical signal received from the coded response is determined, that is, the intensity of the electrical signal, such as the RSSI (Received Signal Strength Indication) level, or the phase between the received electrical signals and the transmitted electrical signals. When the radio frequency transponder associated with an object is rotating during the vehicle's movement, that is, moving in a planar direction around a fixed axis of rotation relative to the vehicle, the geographical position of the radio frequency transponder in a fixed frame of reference of the vehicle is constantly changing. Therefore, the position of this radio frequency transponder changes over time relative to the radio frequency antenna, which is fixed to the non-rotating parts of the vehicle whose communication area covers the said radio frequency transmission.Thus, the measured phase or amplitude, which depends on the distance between the radio frequency transponder and the radio frequency antenna, is constantly changing. Conversely, a radio frequency transponder attached to a fixed object on the vehicle has a fixed position relative to the vehicle's radio frequency antenna. Therefore, the phase or amplitude is constant or nearly constant over time. Measuring this phase or amplitude can thus provide information about the mobility of the connected object, and therefore its movement, by comparing the phases for the same radio frequency transponder during the same vehicle movement.

[0011] To identify the radio frequency transponder or the connected object on which it is attached, it is necessary to determine the unique identifier of the radio frequency transponder which is found in the coded response emitted by the transponder.

[0012] The determined phase or amplitude and the unique identifier are then stored in a memory space for each coded response. Next, if the associated coded responses are greater than or equal to two, the set of determined phases or amplitudes is selected for the same unique identifier and evaluated against a reference. This reference can be a fixed value, but preferably it is a value associated with the population of determined quantities of the same unique identifier. In particular, this reference can be a metric such as the mean value, median value, standard deviation, etc., of a similar quantity corresponding to electrical signals of coded responses when the vehicle is stationary, for example. The metric of a quantity of the electrical signal emitted by a fixed radio frequency transponder in the vehicle changes only slightly regardless of the vehicle's operating condition, whether stationary or moving.

[0013] Finally, if one of the determined quantities, ideally several quantities, deviates from the reference beyond a threshold S, the unique identifier associated with the list of determined quantities is stored in a first list of the vehicle's rotating assemblies. Otherwise, the unique identifier is not taken into account because it is considered to be attached to a fixed connected object of the vehicle. The threshold S allows for the elimination of measurement noise in electrical signals and ensures the correct selection of unique identifiers that are rotating.

[0014] In conclusion, the proposed method makes it possible to identify all the rolling mounted assemblies of the vehicle by radio frequency communication during the movement of the vehicle, that is to say, to carry out an inventory of the rolling mounted assemblies through the unique identifier of the radio frequency transponder associated with the mounted assembly by one of the connected objects forming the mounted assembly.

[0015] According to a first embodiment, the quantity evaluation step comprises the following step: • The reference corresponds to the value of the magnitude of one of the at least two coded responses.

[0016] More specifically, the magnitude evaluation step includes the following step: • Calculate a mean or median of the magnitudes among the at least two coded responses for each determined identifier; the mean or median becoming the reference.

[0017] In this first embodiment, the evaluation of the quantities for the same unique identifier consists of a comparison of the quantities with respect to a reference. If this comparison, which can be a difference or a ratio, exceeds a threshold S, this means that a portion of the quantities, and therefore of the coded responses bearing the same unique identifier, is further removed than other quantities from the rest of the population of identified quantities.

[0018] This is perfectly understandable when the reference is one of the identified quantities from the population of quantities with the same unique identifier, or when the reference is calculated, corresponding, for example, to the mean or median of the population of identified quantities with the same unique identifier. This calculated reference is inherently significant within the population of identified quantities, that is, among the quantities of at least two identified coded responses bearing the same unique identifier. The mean or median are examples of a metric significant within the population of identified quantities of coded responses bearing the same unique identifier.

[0019] According to a second embodiment, where the number of coded responses identified is greater than three, the quantity evaluation step comprises the following steps: • Calculate a mean or median of the at least three quantities found among the coded responses for each determined identifier, with the mean or median becoming the reference; • Calculate a standard deviation associated with the reference of at least three quantities found; and the step of evaluating the distance of each quantity from the reference includes the following steps: • Compare the standard deviation of the quantities with respect to a threshold S', S' being greater than or equal to the threshold S; • If the standard deviation is greater than S', store the unique identifier associated with these at least three coded responses found in the specific memory space.

[0020] If the number of coded responses for the same identifier becomes large, a statistical approach is possible. This involves defining, on the one hand, a mean or median and a standard deviation, associated with all the determined values ​​of the coded responses concerned. The mean or median then naturally becomes the reference. And the standard deviation, by comparison to a threshold value S', makes it possible to determine whether the electronic device associated with the identifier is stationary or in motion.

[0021] Advantageously, the duration T of the radio frequency interrogation step is greater than 30 milliseconds, preferably 40 milliseconds.

[0022] This is the time required to reliably obtain a response from the radio frequency transponder to the emission of the detection signal by the transmitting system.

[0023] Very advantageously, knowing the vehicle's rolling speed V, the duration T of the radio frequency interrogation step of at least one memory space of the radio frequency transponders is greater than two wheel rotations of the vehicle assembly with the largest diameter.

[0024] For rotating assemblies with a radio frequency listening antenna having a spatially limited communication field. The duration of the detection phase must allow the radio frequency transponder to be interrogated during its rotation around the axis of rotation of the assembly. Ensuring at least two rotations of the radio frequency transponder during the detection phase guarantees a minimum communication time between the radio frequency transponder and the radio frequency antenna of the transmitter / receiver system, even if communication between the radio frequency transponder and the radio frequency antenna is not ensured over the entire rotation of the radio frequency transponder.

[0025] Preferably, the vehicle's movement during the detection phase is carried out in a straight line.

[0026] Since the initial objective is to identify rotating radio frequency transponders by analyzing the magnitude of the coded response relative to the transmitted signal, it is necessary, if possible, to avoid detecting radio frequency transponders associated with non-rotating objects such as mounted assemblies, which may have different spatial positions depending on the steering angle of the mounted assemblies. Consequently, their spatial position relative to the radio frequency antenna of the transmitter / receiver system is modified during the turn, potentially leading to a variation in the magnitude of the coded response.

[0027] Most preferably, the vehicle is driven at a constant speed during the detection phase.

[0028] Since the initial objective is to identify rotating radio frequency transponders by analyzing the magnitude of the coded response, it is necessary, if possible, to avoid detecting radio frequency transponders associated with non-rotating objects such as mounted assemblies. These assemblies may have different spatial positions depending on the vehicle's speed, for example, due to the vehicle's suspension system adapting to the driving speed. Consequently, their spatial position relative to the radio frequency antenna is modified during acceleration or deceleration, potentially leading to a variation in the magnitude of the coded response.

[0029] Specifically, the vehicle's movement at the time of the detection phase is carried out under the same weather conditions as the road.

[0030] In order to control measurement noise, either during the same detection phase or between different detection phases, it is preferable that all these detection phases be carried out under identical weather conditions. Indeed, a Changes in measurement noise levels were observed when measurements were taken in dry or rainy weather, for example. The method here refers to relative, not absolute, values; therefore, it is preferable that the detection phases be carried out under identical weather conditions.

[0031] Advantageously, at least one unique identifier is an SGTIN (Serial Global Trade Identification Number) identifier associated with one of the components of the assembled assembly.

[0032] SGTIN identification allows for the unique identification of an object based on its nature at the individual level. Generally, this identifier is stored in the memory of the radio frequency transponder. The radio frequency transponder is attached to the object associated with the identifier. This operation is performed by the party marketing the object. Since the SGTIN contains the object's nature, it allows the communication system to select the identifiers captured based on the object's nature, thus reducing the number of identifiers to be processed. An alternative for the unique identifier is to capture the TID (Tag Identifier) ​​of the electronic chip of an electronic component of the radio frequency transponder.Since this identifier for a radio frequency transponder component is unique, it allows for the unambiguous identification of radio frequency transponders without direct distinction based on the object carrying the radio frequency transponder.

[0033] According to a particular embodiment, the sequence of detection and analysis phases during the same vehicle run is repeated N times, N being an integer greater than or equal to two, the method includes a step of comparing the lists of unique identifiers of the rolling assemblies constituted at each analysis step, and the method includes the construction and storage in a dedicated memory space of the final group of unique identifiers of the rolling assemblies of the vehicle as being that of the unique identifiers of the rolling assemblies common to the set of N lists resulting from a step of comparing the N lists.

[0034] The communication system captures all radio frequency transponders present within its communication range, whether or not they are assigned to the vehicle being inspected. Thus, during the vehicle's movement, the communication system may capture radio frequency transponders from another vehicle in traffic. For example, a vehicle traveling in the opposite direction that crosses paths with the vehicle during the detection phase. Duplicated detection and analysis phases ensure the elimination of radio frequency transponders that are then considered spurious or ephemeral. Indeed, it is rare for two vehicles to travel side-by-side in a coordinated manner for a significant period of time. Generally, the maximum duration of proximity between two vehicles corresponds to the duration of Overtaking between vehicles. Similarly, parasitic radio frequency transponders can also be associated with fixed objects along the route, such as street furniture or road signs. Their fleeting appearance during the analysis phase justifies this method of excluding them from the final list of radio frequency transponders present on the vehicle and attached to the vehicle's rolling stock.

[0035] Preferably, two successive detection phases are separated by a time interval T' greater than 5 seconds.

[0036] This minimum time period generally allows overtaking between two vehicles with a speed difference of 10 km / h.

[0037] The invention also relates to a system for identifying the rolling stock assemblies of a vehicle, capable of being associated with a vehicle, each rolling stock assembly of the vehicle comprising at least one radio frequency transponder communicating by backscattering and comprising at least one unique identifier in a memory space of the radio frequency transponder, comprising: • a radio communication transmitter / receiver system, comprising an electrical signal generator at a center frequency F0, a modulator enabling modulation of the generated electrical signal, a power source, a demodulator capable of demodulating the received electrical signals; • at least one radio frequency antenna galvanically coupled to the radio communication transmitter / receiver system, at least one radio frequency antenna capable of covering in radio frequency communication the spatial area of ​​the vehicle in which all the mounted rolling assemblies of the vehicle are located, 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; • an electrical signal processing device capable of cutting a received electrical signal into at least one coded response; • a coded response reading device capable of identifying the unique identifier and capable of identifying at least one quantity of the electrical signal received from the coded response; • a memory space capable of storing, for each unique identifier identified and for each coded response associated with this unique identifier, at least one quantity of the received electrical signal; • a microprocessor capable of performing at least one operation on the data in memory space to determine the distance of the quantities relative to to a reference and select at least one unique identifier of each rolling radio frequency transponder from a dedicated list.

[0038] According to a specific embodiment, the at least one radio frequency antenna comprises at least four radio frequency antennas, each radio frequency antenna having a radio frequency communication area capable of covering a spatial area comprising at least one mounted rolling assembly located at an axial end of an axle of the vehicle.

[0039] According to a preferred embodiment, the at least one radio frequency antenna comprises two radio frequency antennas, each radio frequency antenna having a radio frequency communication area capable of covering a spatial area comprising all the mounted rolling assemblies located on the same side of the vehicle with respect to the average axial plane of the vehicle.

[0040] The system enables the implementation of a method for identifying the rolling stock assemblies of a vehicle. This system can be fully or partially integrated into the vehicle. If the microprocessor performing the data operations is located outside the vehicle, the unique identifiers and the received electrical signal values ​​must be transmitted outside the vehicle via specific communication means. The list of unique rolling stock identifiers for the vehicle must then be transmitted to the vehicle or to a fleet management system for possible display on a human-machine interface. However, the device can also be fully installed on the vehicle, particularly to inform the vehicle of inventory results or to feed other functionalities or devices requiring knowledge of these results.The quantities of the received electrical signal are either the signal intensity (as measured, for example, by the RSSI) or the phase difference between the received electrical signal and the electrical signal generated by the transmitting system. Generally, the device for reading the electrical signals is integrated into the transmitter / receiver system.

[0041] For this inventory, the system can have different radio frequency antenna configurations for the detection phase. In a first embodiment, the volume comprising the housing cavity at each axial end of each axle of the vehicle is covered by a specific radio frequency antenna. This antenna then identifies the rolling assembly(ies) present at the end of the axle using the method of the invention. As an added benefit, the vehicle configuration, i.e., the identification of the radio frequency antenna that has captured at least one unique identifier, provides information on the location of this at least one unique identifier on the vehicle.

[0042] Regardless of the embodiment of the system on the vehicle, whether partially or totally integrated into the vehicle, while the vehicle is in motion, the system and The processes implemented by this system are operational. If necessary, the parameters may need to be adjusted according to the vehicle's operating mode to improve their efficiency. Brief description of the drawings

[0043] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the accompanying figures, in which the same reference numbers designate identical parts throughout and in which: - Fig. 1 presents a perspective view of a vehicle equipped with an identification system to carry out the inventory of mounted rolling assemblies according to a preferred mode. - Figure 2 presents a flowchart of the inventory process according to the invention. - Figure 3 represents an example of an assembly mounted according to a method of realization, - Figure 4 schematically illustrates one possible implementation of a system of radiocommunication, - Figure 5 presents the results of coded responses between various vehicle radio frequency transponders. Detailed description of implementation methods

[0044] The method and system presented are applicable to any type of land vehicle. They are particularly applicable to automobiles but can also be applied to trucks with more than two axles. They can also be applied to self-guided vehicles or ground drones.

[0045] Fig. 1 presents a perspective view of the implementation of the identification system 3 in a means of transport 2 of the motor vehicle type.

[0046] The motor vehicle 2 is represented here by a transparent volume representing the closed, fitted body, which corresponds to the complete vehicle from which the axles and powertrain have been removed. However, four cavities, labeled 21a-1, 21a-2, 21b-1, and 21b-2, are visible on this vehicle 2, each capable of housing a vehicle assembly. The assembly here comprises radio frequency devices such as RFID tags and / or a TMS sensor on the tire.

[0047] This vehicle 2 also includes the identification system 3 enabling communication with the radio frequency devices of the mounted assemblies. This identification system 3 includes a first radio communication system 31 and some Radio frequency antennas 32a and 32b. The radio communication system 31 includes a system for transmitting and receiving electrical signals located in the vehicle 2 at the level of the bulkhead, which is a predominantly vertical wall relative to the ground along which the vehicle moves, generally separating the engine compartment of the vehicle, here located at the front of vehicle 2, from the passenger compartment. This system 31 therefore includes the electrical signal transmitter as well as the electrical signal demodulator. In this particular case, the system 31 also includes the electrical signal reading device.

[0048] From this system 31, two bidirectional communication cables 32a and 32b extend to the left and right sides of the vehicle 2, respectively. These communication cables are traveling wave cables and are mounted on the system 31 to form a galvanic connection. Each cable 32a, 32b runs through the structure of the vehicle 2 to reach the vicinity of at least one cavity for mounting the assemblies. Each cable includes a signal transmission section originating from the system 31, which then becomes a radiating section, thus forming radio frequency antennas.

[0049] In fact, as illustrated in [Fig. 1], each cable 32a, 32b reaches the vicinity of two mounting cavities, each corresponding to the front and rear axles of the vehicle 2. At the first cavity 21a-1, the cable 32a has a continuous section 32a-1 located at the wheel arch, describing an angular sector of 120 degrees around the axis of the front axle. This section 32a-1 of the communication cable 32a is located within the communication zone of the radio frequency devices of the mounting assembly to be housed in cavity 21a-1. Thus, this section of the communication cable 32a will communicate with the radio frequency devices of the mounting assembly present in the mounting cavity 21a-1. However, nothing prevents this 32-a communication cable from entering into radio frequency communication with other electronic devices operating on the same communication frequency.

[0050] 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 radiating section 32a-2 located in the communication zone of the radio frequency devices of the assembly to be housed in the cavity 21a-2. The second continuous radiating section 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 steerable here; consequently, the assembly moves little or not at all angularly during the driving phase. Therefore, radio frequency communication between the continuous radiating section 32a-2 of the bidirectional communication cable 32a is facilitated by compared to that of part 32a-1, where the axle is directional, generating an angular movement of the assembly when turning, for example. These two continuous, radiating parts 32a-1 and 32a-2 are here disjointed and each only allows communication with one assembly, but they could be joined. However, in the case of a dual-wheel axle, such as in a utility vehicle in traction mode, the continuous part 32a-2 located near the cavity 21a-2 would allow communication with the various dual-wheel assemblies located on the same axle and on the same side of the vehicle 2. And, it is entirely conceivable that between the two parts 32a-1 and 32a-2 of the communicating cable 32a, the cable is also partially communicating, which would also allow communication with electronic devices located along the path of the cable 32a.

[0051] Similarly, due to the symmetry of the motor vehicle 2 with respect to the mean axial plane 10 of the vehicle 2, the communication cable 32b comprises a radiating section having two continuous, disjointed sections, 32b-1 and 32b-2, each communicating with a mounted assembly located respectively on the front axle and the rear axle. The mean axial plane divides the vehicle 2 into two substantially equal and symmetrical parts; the dashed line within the plane 10 represents the intersection of the vehicle 2 with the plane 10. The total length of the bidirectional communication cable 32a and 32b does not exceed 5 meters. The length of the continuous, radiating sections 32a-1, 32a-2, 32b-1, and 32b-2 is greater than 50 centimeters, corresponding to one-quarter of the circumference of a passenger vehicle tire. This length is beyond the unit of cable length for UHF radio frequency communication at 920 MHz or 2.4 GHz.

[0052] Fig. 2 presents a synoptic diagram of the method for identifying the rolling assembly units of a vehicle.

[0053] This method comprises two distinct phases. The first phase, 2001, corresponds to the phase of detecting radio frequency transponders through the vehicle identification system. The first phase, 2001, of the method is implemented when the vehicle is traveling on the road. This first phase, 2001, includes a first step, 1001, which is responsible for emitting interrogation electromagnetic waves through the vehicle identification system. This step aims to generate electromagnetic waves through the vehicle's radiating antennas; this consists of generating and modulating an electrical signal centered on a communication frequency F0 of the radio frequency transponders. The signal requests the interrogation of a specific memory space of the radio frequency transponder containing a unique identifier.

[0054] In response to this interrogation signal, the radio frequency transponder emits a backscattered signal from the received electromagnetic waves containing the requested unique identifier.

[0055] The second step of process 1002 therefore corresponds to the reception of the electromagnetic waves emitted by the radio frequency transponder via the same radio frequency antenna. This electromagnetic signal is then converted into an electrical signal containing the information on the unique identifier of the radio frequency transponder.

[0056] The second phase 2002 of the process of identifying the mounted assemblies rotating or rolling of the vehicle, which can take place during the rolling of the vehicle, corresponds to the phase of analysis of the recovered electrical signals.

[0057] The first step 1003 of this second phase 2002 consists of extracting from the electrical signal received by the identification system the various coded responses from the various radio frequency transponders. This is facilitated, if necessary, by encoding the response, which begins and / or ends with explicit frames that allow the coded responses to be identified on the electrical signal. Furthermore, in backscattering, it is possible to assign latency periods to the responses for each detected individual, thus distributing the signals over time and potentially avoiding collisions between the coded responses. All of these aspects make it possible to separate the electrical signal received by the electrical signal processing device into a multitude of coded responses, each individually associated with a radio frequency transponder by its unique identifier.

[0058] Next, the analysis phase 2002 includes a step 1004 for determining the information in each coded response. Specifically, from each coded response, the unique identifier associated with the radio frequency transponder is extracted, as well as electrical signal parameters such as the electrical signal strength, known as RSSI (Received Signal Strength Indicator), or the phase difference between the signal received by backscattering and the electrical signal emitted by the identification system. These two electrical signal parameters can then be used to distinguish radio frequency transponders from the vehicle's rolling stock.

[0059] The next step 1005 of the second phase 2002 consists of evaluating the magnitude of the electrical signal against a reference magnitude. The metric of this reference magnitude may be the mean or the median magnitude for all coded responses with the same unique identifier. If the number of coded responses with the same unique identifier is high, the metric may be an indicator of the dispersion of the magnitudes, such as the standard deviation or the population variance of the magnitudes of the coded responses with the same unique identifier.

[0060] Next, a test is performed by comparing each quantity or the statistical indicators of the population of determined quantities against a threshold S. This comparison can be the difference between the quantity and the reference quantity, or the ratio between the quantity and the reference quantity. If the entire population of quantities is close to the reference quantity, that is, if all comparisons of the quantities with the reference are below a threshold S, this means that the radio frequency transponder associated with the unique identifier is fixed in the vehicle. Conversely, if at least one quantity deviates from the reference beyond the threshold S, which corresponds to step 1006, this means that during driving, the radio frequency transponder moved relative to the vehicle's radio frequency antenna. Therefore, the radio frequency transponder associated with the unique identifier is mobile relative to the vehicle.In conclusion, it is appropriate to have a unique identifier in a specific list corresponding to step 1007.

[0061] However, this mobile transponder may not be present on the vehicle under study but present on an object along the vehicle's route such as street furniture or present on another vehicle which would be near the vehicle under study due to an overtaking or crossing between said vehicles.

[0062] Therefore, optionally, one or more iterations of the associated detection phase 2001 and analysis phase 2002 should be repeated to determine whether the unique identifier(s) captured during a first iteration are still present during other iterations corresponding to a different period. These iterations must have been carried out during the same vehicle operation; that is, without switching off the powertrain ignition.

[0063] These successive iterations are indicated in [Fig. 2] by the dashed connecting lines. When several iterations have been performed, i.e., several specific lists have been determined, the next step 1008 of the analysis phase consists of comparing the determined unique identifiers present in the specific lists of the N iterations. All the unique identifiers present across all the iterations are considered to be the identifiers of the vehicle's rolling assemblies, since these are continuously detected during driving at several different times. They are then placed in the final group of the vehicle's rolling assemblies in step 1009. If only one iteration is performed, there is uniqueness between the specific list of unique identifiers resulting from step 1007 and the final group of the vehicle's rolling assemblies resulting from step 1009.

[0064] Fig. 3 illustrates an example of a mounted assembly adapted to be inserted into a housing cavity of the transport vehicle.

[0065] The assembled unit 40a-1 is more particularly adapted for insertion into the respective cavity 20a-1. Assembled units adapted for insertion into the the respective cavities 20a-2, 20b-1, 20b-2, may be identical or similar to this mounted assembly shown in [Fig.3].

[0066] This assembled unit, or wheel, 40a-1 comprises a pneumatic casing (or more simply, a tire) 42a-1 and a rim 43a-1.

[0067] A passive radio frequency transponder device 41a-1 is attached to this assembly. It can be positioned directly on or within the tire 42a-1. In particular, it can be embedded within the tire structure itself. It can also be positioned on the rim 43a-1.

[0068] The assembled unit may also include equipment such as a TPMS (for "Tire Pressure Monitoring System"), a TMS (for "Tire Mounted System"), etc.

[0069] The radio frequency transponder may be designed to communicate by backscattering. Such a transponder may, for example, be a UHF RFID tag conforming to ISO 1800-6.

[0070] Backscatter communication is a method of data transmission 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 passive radio frequency transponders are associated with a center frequency, which must be known to the interrogating device.

[0071] 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 point is particularly crucial given the difficulty of powering a device embedded in a mounted assembly.

[0072] 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.

[0073] The radio frequency transponder 41a-1 includes at least one unique identifier stored in a memory space of this transponder.

[0074] The energy of the signal received from a radio communication transmitter / receiver system (for example, from an RFID reader) allows the radio frequency transponder chip to modulate this signal according to the data it wishes to transmit. It is envisaged 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.

[0075] This unique identifier can, for example, be an identifier of the radio frequency transponder (in particular its chip) or an identifier of an element of the assembly mounted 40a-1, for example from its rim or, preferably, from its tire casing 42a-1. These element identifiers can be the serial numbers of these elements.

[0076] In particular, a unique identifier may be an SGTIN identifier associated with a component of a respective assembled assembly.

[0077] The SGTIN (acronym for "Serialized Global Trade Item Number") combines the GTIN (for "Global Trade Item Number") of a product with a unique serial number. The structure is: • “EPC Header” (Electronic Product Code header, or “Electronic Product Code): Indicates that this is an SGTIN and specifies the length of the other fields. • “GSI Company Prefix”: Identifies the company who produced or distributed the relevant element of the assembled unit. • “Item Reference”: Designates the type of item (equivalent to GTIN or EAN barcode). • “Serial Number”: A number to differentiate each element.

[0078] According to embodiments, the memory space of the passive 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.

[0079] The inventory system 3 for the mounted rolling assemblies includes a radio communication system 31.

[0080] This radio communication system 31 which can be composed of one or more devices, each performing one or more functions as illustrated in [Fig.4].

[0081] These devices constituting the radio communication system 31 can be distributed in the vehicle or co-located, for example at the level of the firewall, which is a wall 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.

[0082] The system 31 includes, in particular, a radio communication transmitter / receiver system 311. This system may be designed to modulate and demodulate electrical signals. In particular, it can convert digital signals into analog signals and vice versa. These analog signals are representative of the electromagnetic waves emitted or received by means of antennas 32a, 32b galvanically connected to this transmitter / receiver system 311.

[0083] 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.

[0084] The radio communication system 31 may include an electrical signal processing device 312 which 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 passive radio frequency transponder.

[0085] It is noted that passive 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. It is therefore possible, in the vast majority of cases, to segment, or isolate, the responses within the received signal.

[0086] The system 31 also includes a device 313 which can control the detection phase, and in particular, initiate the detection phase and trigger an analysis phase depending on the driving conditions, or determine whether the detection phase should be maintained. This includes verifying that a sufficient number of responses have been received. To this end, the values ​​provided by the sensor 33 can be recorded in order to verify in real time whether this stopping criterion is met or to observe the associated driving condition, such as constant speed or weather conditions.

[0087] The analysis phase can be triggered subsequently to the detection phase.

[0088] The analysis phase includes a first step, which can be implemented by the reading device 314, in order to determine, for each received signal (i.e. for each response from a passive radio frequency transponder): • The unique identifier encoded in this signal, • And at least one quantity of the electrical signal.

[0089] The radio communication system 31 can thus associate a received response with a given passive radio frequency transponder. Analysis of the magnitude of the electrical signal makes it possible, preferably statistically, to determine whether the transponder is linked to a rolling assembly of the vehicle or to another object that is fixed in the vehicle.

[0090] A microprocessor 315 is provided to determine, for each unique identifier coded in each electrical signal, a set of quantities of the corresponding electrical signal.

[0091] Based on an evaluation of the dispersion of the quantities in this set, it can deduce whether the unique coded identifier corresponds to a mounted rolling assembly of the vehicle.

[0092] More specifically, if there is a dispersion beyond a certain threshold then the unique coded identifier corresponds to a mounted rolling assembly of the vehicle.

[0093] If there is no dispersion beyond a certain threshold, then the unique coded identifier corresponds to an object in the vehicle that is fixed, i.e. not rotating in the vehicle.

[0094] The evaluation of the dispersion of the measured quantity on electrical signals containing a unique identifier of a given radio frequency transponder forms a criterion for differentiating between objects rotating on an axle of the vehicle and objects positioned on the fixed parts of the vehicle.

[0095] Dispersion can be assessed in various ways. For example, it can be based on a metric such as a mean, a median, a standard deviation, and / or a variance. Any other estimator of the dispersion of a statistical population can obviously be used.

[0096] The presence and absence of dispersion can be determined by comparing this assessment of dispersion with a threshold.

[0097] Also, we can compare the dispersion assessments for the two populations, and compare (for example) their difference or their ratio with respect to a threshold.

[0098] The threshold can be arbitrarily set; its purpose is to ensure that two populations corresponding to different dispersions are indeed obtained. It can, in the limit, be as small as desired, but greater than zero.

[0099] It is therefore observed that the passive radio frequency transponders of the axle-mounted assemblies 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 an axle-mounted assembly is installed by studying the variation in the magnitude associated with the electrical signals that contain the unique identifier of that axle-mounted assembly.

[0100] Conversely, an object installed on a fixed part of the vehicle does not generate any variability in the measured quantity on the electrical signal containing a unique identifier corresponding to that object.

[0101] It is therefore possible to locate an assembly mounted on an axle or a fixed object of the vehicle.

[0102] Optionally, the device 313, which manages the detection and analysis phases of the process, communicates with a device 33 of the vehicle that is sensitive to the vehicle's direction and / or its speed and / or weather conditions. This preferably ensures that the analysis focuses on quantities corresponding to straight-line driving and / or driving at a constant speed and in similar weather conditions. "Constant speed driving" means that the vehicle travels within a speed range around an average speed, with the limits of these limits not exceeding 3 m / s from the average speed and the average speed being less than 30 m / s. Similarly, the term "straight line driving" means that the steering angle of the vehicle does not exceed + / - five degrees.

[0103] Fig. 5 is an illustration of the results of the process for identifying the rolling assembly units of a vehicle.

[0104] In this particular case, the vehicle has a steering axle located at the front of the vehicle when in forward gear and a non-steering axle located at the rear of the vehicle. The tires of the mounted assemblies placed on the axles are equipped with radio frequency transponders operating at a communication frequency of 915 MHz in the form of an RFID (Radio Frequency Identification) tag embedded in the tire's structure on the sidewall. This tag is equipped with a helical radio frequency antenna coupled to an electronic chip. The electronic chip includes a memory space containing the SGTIN-96 identifier of the tire, which represents a unique identifier for the tire and therefore for the radio frequency transponder placed on that tire.Furthermore, the vehicle also includes fixed objects within the vehicle, including a radio frequency transponder also operating at the F0 communication frequency.

[0105] We will analyze the results of a rolling mounted assembly transponder whose category will be referenced by the term "Rotating" and of a radio frequency transponder of a fixed object of the vehicle whose category will be referenced by the term "Fixed".

[0106] During vehicle operation, a radio frequency transponder detection phase will be initiated using a system shown in Figures 1 and 4 above. The results of the analysis phase for a single radio frequency transponder per category are illustrated in [Fig. 5].

[0107] For each category, a population of coded responses is defined, distributed around a mean or median value. The population distribution of these responses is illustrated by the height of the vertical segment delimited by horizontal lines. Within each population, the density of the population of coded responses around the mean value is denoted by a rectangular shape, this rectangle including more than 80% of the population of coded responses. The unit chosen for the responses is the intensity of the electrical signal received in return for the query, expressed in RSSI (Accepted Signal Strength Indication). For each category, we define a reference Ref 1, Ref 2 which here corresponds to the average value of a population attached to the same unique identifier.

[0108] The comparison of each response is made with respect to the reference Ref 1 or Ref 2. For each population, a threshold value has been defined delimiting two limits, an upper limit 103 or 104 and a lower limit 105 or 106 per population with respect to the reference Ref 1 or Ref 2 of the population.

[0109] On the left side of the graph, the population of responses for an object in the "Fixed" category is visualized. The level of responses is observed to be homogeneous, with a small rectangle height, indicating that the majority of the population is not very dispersed. The population boundaries are symbolized by the endpoints of the vertical segment.

[0110] In this case, we observe that for the threshold value, no response from the population is far from the reference Ref 1 beyond the limits 103 and 105 defined by the threshold value with respect to the reference Ref 1. As a result, the unique identifier of these responses cannot be put in the list of mounted rolling assemblies of the vehicle.

[0111] On the right-hand side of the figure, the population of responses for an object in the "Turning" category is visualized. It can be observed that the level of responses is more spread out than for the population in the "Fixed" category, which is reflected both in the greater height of the rectangle and in the fact that the limits of the population segment are further from reference 102. Consequently, the population is more dispersed. The population limits are symbolized by the endpoints of the vertical segment.

[0112] In this case, we observe that for the same threshold value, some responses from the population are far from the reference Ref 2 beyond the limits 104 and 106 defined by the threshold value in relation to the reference 102. As a result, the unique identifier of these responses can be placed in the list of mounted rolling assemblies of the vehicle.

Claims

Demands

1. A method for identifying the rolling assembly units of a vehicle, each assembly unit comprising at least one radio frequency transponder communicating by backscattering and comprising at least one unique identifier in a memory space of the radio frequency transponder, the vehicle comprising a radio communication system, galvanically coupled to at least one radio frequency antenna, the at least one radio frequency antenna covering in radio frequency communication at least one spatial area of ​​the vehicle in which all the rolling assembly units of the vehicle are located, comprising the following phases: Launch a detection phase (2001) during a vehicle drive, comprising the following steps: • Launch a radio frequency interrogation step (1001) of at least one memory space of the radio frequency transponders communicating in backscatter containing at least one unique identifier for a duration T; • To receive (1002), via at least one radio frequency antenna, for the duration T, radio waves backscattered by radio frequency transponders communicating in backscattering; Launch an analysis phase (2002) after the detection phase (2001) comprising the following steps: • Identify (1003), via an electrical signal processing device (312), the coded responses contained in the received radio waves; • Determine (1004) the unique identifier and at least one quantity of the electrical signal received for each coded response via a reading device (314); • For each unique identifier determined for at least two identified coded responses, evaluate (1005) each of at least one magnitude (¢) against a reference (Ref 1, Ref 2); • If at least one quantity (¢) is far from the reference (Ref 1, Ref 2) by a threshold S (1006), place (1007) the unique identifier associated with these at least two coded responses in a specific list stored in a memory space otherwise erase the determined unique identifier.

2. A method for identifying the rolling assembly units of a vehicle according to claim 1, wherein the magnitude (¢) of the received signal is included in the group comprising the amplitude of the received electrical signal and the phase of the received signal relative to the generated electrical signal.

3. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 2, wherein the quantity evaluation step (1005) includes the following step: • The reference (Ref 1, Ref 2) corresponds to the value of the quantity (¢) of one of the at least two coded responses.

4. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 2, wherein the step of evaluating the quantities comprises the following step: • Calculate a mean or a median of the quantities (¢) among the at least two coded responses for each determined identifier; the mean or the median becoming the reference (Ref 1, Ref 2).

5. A method for identifying the rolling stock assemblies of a vehicle according to any one of claims 1 to 2, wherein, where the number of coded responses found is greater than three, the quantity evaluation step (1005) comprises the following steps: • Calculating the mean or median of the quantities (¢) among the at least three coded responses for each determined identifier; the mean or median becoming the reference (Ref 1, Ref 2); • Calculating a standard deviation associated with the reference of the at least three quantities (¢) found; and the step of evaluating the distance of each quantity from the reference (1006) comprises the following steps: • Compare the standard deviation of the quantities (¢) with respect to a threshold S', S' being greater than or equal to the threshold S; • If the standard deviation is greater than S', store the unique identifier associated with these at least three coded responses found in the specific memory space (1007).

6. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 5 wherein the duration T of the radio frequency interrogation step (1001) is greater than 30 milliseconds, preferably 40 milliseconds.

7. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 6 wherein, knowing the rolling speed V of the vehicle, the duration T of the radio frequency interrogation step (1001) of at least one memory space of the radio frequency transponders is greater than two wheel rotations of the vehicle assembly having the largest diameter.

8. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 7 wherein the rolling of the vehicle at the time of the detection phase (2001) is carried out in a straight line.

9. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 8 wherein the rolling of the vehicle at the time of the detection phase (2001) is carried out under the same weather conditions as the road.

10. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 9 wherein at least one unique identifier is an SGTIN (Serial Global Trade Identification Number) identifier associated with one of the components of the assembly.

11. A method for identifying the rolling assembly components of a vehicle according to any one of claims 1 to 10, wherein the sequence of detection (2001) and analysis (2002) phases during the same vehicle run is repeated N times, N being an integer greater than or equal to two, the method includes a step of comparing the lists (1008) of unique identifiers of the rolling assembly components constituted at each analysis step, and the method includes the construction and storage in a space dedicated memory of the final group (1009) of the unique identifiers of the vehicle's rolling assembly units as being that of the unique identifiers of the rolling assembly units common to all the N lists resulting from a comparison step of the N lists (1008).

12. Method for identifying the rolling assembly units of a vehicle according to claim 11 in which two successive detection phases (2001) are separated by a time interval T' greater than 5 seconds.

13. Identification system (3) for the rolling assembly units of a vehicle, capable of being associated with a vehicle (2), each rolling assembly (40a-1) of the vehicle comprising at least one radio frequency transponder (40a-1) communicating by backscattering and comprising at least one unique identifier in a memory space of the radio frequency transponder (41a-1), comprising: • a radio communication transmitter / receiver system (311), comprising an electrical signal generator at a center frequency F0, a modulator for modulating the generated electrical signal, a power source, a demodulator capable of demodulating the received electrical signals. • at least one radio frequency antenna (32a, 32b) galvanically coupled to the radio communication transmitter / receiver system (311), at least one radio frequency antenna (32a, 32b) capable of covering in radio frequency communication the spatial area of ​​the vehicle (2) in which all the mounted rolling assemblies (40a-1) of the vehicle are located, 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 received electrical signals. • An electrical signal processing device (312) capable of cutting a received electrical signal into at least one coded response; • A coded response reading device (314) capable of identifying the unique identifier and capable of identifying at least

14.

15. a quantity of the electrical signal received from the coded response; • A memory space capable of storing, for each unique identifier identified and for each coded response associated with this unique identifier, at least one quantity of the received electrical signal; • A microprocessor (315) capable of performing at least one operation on the data in the memory space to determine the distance of the quantities from a reference and to select at least one unique identifier of each rolling radio frequency transponder from a dedicated list. Identification system (3) of the rolling mounted assemblies of a vehicle according to claim 13 wherein at least one radio frequency antenna comprises at least four radio frequency antennas, each radio frequency antenna having a radio frequency communication area capable of covering a spatial area (21a-l, 21a-2, 21b-l, 21b-2) comprising at least one rolling mounted assembly (41a-l) located at an axial end of an axle of the vehicle. Identification system (3) of the rolling assembly units of a vehicle according to claim 13 wherein at least one radio frequency antenna comprises two radio frequency antennas (32a, 32b), each radio frequency antenna (32a, 32b) having a radio frequency communication area capable of covering a spatial area (21a-l, 21a-2, 21b-l, 21b-2) comprising all the rolling assembly units (41a-l) located on the same side of the vehicle with respect to the mean axial plane (10) of the vehicle.

Images