Method and system for identifying the rolling assembly components 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: • Launching a first detection phase, with the vehicle stationary, then a second detection phase, with the vehicle in motion, each phase comprising: Launching an interrogation phase for a duration T; Receiving, for the duration T, radio waves backscattered by the radio frequency transponders; • Launching an analysis phase comprising: Identifying the coded responses; Determining the unique identifier; For each unique identifier determined, evaluating the read rate for each detection phase;Deduce whether the determined unique identifier is fixed to a mounted rolling assembly of the vehicle. 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 an initial detection phase when the vehicle is stationary, including the following steps: • Launch a first 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 Tl; • To receive, via at least one radio frequency antenna, for the duration Tl, radio waves backscattered by radio frequency transponders communicating in backscattering; • Launch a second detection phase during vehicle operation, comprising the following steps: • Launch a second 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 T2; • To receive, via at least one radio frequency antenna, for the duration T2, radio waves from radio frequency transponders communicating in backscattering; • Launch an analysis phase after the detection phases, including the following steps: • Identify, via an electrical signal processing device, the coded responses contained in the received radio waves; • Determine a unique identifier for each coded response via a reading device; • For each determined unique identifier, evaluate the number of received signals containing said determined unique identifier for each detection phase; • Define a read rate for each detection phase for each determined unique identifier; and • Based on the comparison of the defined read rates between the two detection phases for the same determined unique identifier, deduce whether said determined unique identifier corresponds to a mounted rolling assembly of the vehicle and then place the determined unique identifier of a mounted rotating assembly in a specific memory space.

[0006] 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.

[0007] The method just described solves the technical problem for the following reasons. During the detection phase, which takes place first when the vehicle is stationary and then when the vehicle is in motion, the method captures all the responses from the radio frequency transponders that are located In areas of interest relative to the target, the vehicle's mounted systems are monitored. Ideally, communication is achieved with all the vehicle's radio frequency transponders. However, we are certain to receive all radio frequency transponders belonging to a moving vehicle mounted system, provided that this mounted system has a radio frequency transponder and that it is operational. Furthermore, since radio communication is not spatially limited, it is possible to also receive radio frequency transponders located outside the target vehicle. These 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.

[0008] 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, because of the interrogation protocols used. For example, by assigning each transmitted signal a random response time, i.e., a latency period, 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 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.

[0009] For each coded response, the unique identifier transmitted in the electrical signal of the coded response is read by means of a coded response reading device. This unique identifier makes it possible to identify the radio frequency transponder or the object on which it is positioned

[0010] Next, for each unique identifier identified in the various coded responses received, the number of coded responses associated with the unique identifier is counted for each detection phase.

[0011] Based on the number of responses received for each detection phase, a read rate is defined, corresponding to the number of responses received over a specific time unit. Naturally, the time unit for the read rate is the same for both defined read rates to facilitate comparison. This read rate per detection phase is therefore proportional to the number of responses received and is insensitive to the duration of the detection phase.

[0012] Since these two phases have potentially different durations T1 and T2, a read rate is determined from the number of coded responses recorded for each detection phase, thus allowing for easy comparison between the two detection phases. Comparing the read rates makes it possible to determine whether a radio frequency transponder is attached to a fixed object within the vehicle or is moving relative to the fixed part of the vehicle.

[0013] In conclusion, the proposed method makes it possible to identify the group of rolling vehicle assemblies by radio frequency communication on demand even during the movement of the vehicle, that is to say, to carry out an inventory of the rolling assemblies through the unique identifier of the radio frequency transponder associated with the assembly mounted by one of the connected objects forming the assembly mounted.

[0014] Advantageously, each duration of the radio frequency interrogation steps is greater than 30 milliseconds, preferably 40 milliseconds.

[0015] This is the time required to reliably obtain a response from the radio frequency transponder communicating in backscatter to the emission of the detection signal by the transmitting system.

[0016] Very advantageously, knowing the vehicle's rolling speed V, the duration T2 of the second detection phase is greater than two wheel rotations of the vehicle assembly with the largest diameter.

[0017] 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.

[0018] Preferably, the vehicle's movement during the second detection phase is carried out in a straight line.

[0019] Since the initial objective is to identify rotating radio frequency transponders by analyzing the coded response, it is necessary to avoid, if possible, 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, which potentially leads to a variation in the magnitude of the coded response, even to the point of no response.

[0020] Most preferably, the vehicle's movement during the second detection phase is carried out at a constant speed.

[0021] Since the initial objective is to identify rotating radio frequency transponders by analyzing 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, even to the point of no response at all.

[0022] Specifically, the vehicle's movement during the second detection phase is carried out under the same meteorological conditions as the first detection phase.

[0023] 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 change in the measurement noise level has been observed when measurements are taken in dry or rainy weather, for example. The method refers here to relative and not absolute values; therefore, it is preferable that the detection phases be carried out under identical weather conditions.

[0024] Advantageously, at least one unique identifier is an SGTIN identifier associated with one of the components of the assembled assembly.

[0025] 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.

[0026] According to a complementary embodiment, during said analysis phase, for each coded response, determination of at least one quantity of the electrical signal associated with the coded response, and for each unique identifier determined and for each of the at least two detection phases, determination of a set of quantities of the corresponding electrical signal; and wherein said deduction of whether a unique identifier determined corresponds to a mounted rolling assembly of the vehicle is also based on an evaluation of the dispersion of said quantities in said assemblies by comparison between the quantities corresponding to each of the first and second detection phases.

[0027] Specifically, said quantity of the electrical signal associated with the coded response is based on a measurand included in the group comprising an amplitude of the electrical signal, a phase of the electrical signal received with respect to an electrical signal emitted by the radiocommunication system.

[0028] More specifically, said dispersion is evaluated according to a metric included in the group comprising a mean value, a median value, a standard deviation and a variance.

[0029] 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. Consequently, 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 associated with 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. Analyzing the dispersion of this phase or amplitude can thus provide information about the mobility of the associated connected object, and therefore its movement, by comparing the values ​​for the same radio frequency transponder during a change in the vehicle's driving mode, i.e., from stopped to moving. If a large number of coded responses are identified, a statistical analysis can be considered. The dispersion is then satisfactorily evaluated through [the following methods / methods]. Proposed metrics. This dispersion can, for example, be assessed by comparing the metrics against a given threshold.

[0030] According to a particular embodiment, the sequence of the detection and analysis phases during the movement of the vehicle 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 the step of comparing the N lists.

[0031] 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 might cross paths with the vehicle during the motion 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 be 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 the overtaking maneuver during the motion phase.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. Finally, the vehicle's parking can trigger parasitic radio frequency transponders linked to other parked vehicles or to the parking area's infrastructure.

[0032] Preferably, two successive detection phases are separated by a time interval T' greater than 5 seconds.

[0033] This minimum time period generally allows overtaking between two vehicles with a speed difference of 10 km / h. It also allows the vehicle, while in motion, to move away from an object, equipped with a radio frequency transponder, fixed on the vehicle's route.

[0034] The invention also relates to a system for identifying the rolling assembly units of a vehicle, capable of being associated with a vehicle, each assembly a rolling vehicle assembly comprising at least one radio frequency transponder communicating via backscatter 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 FO, 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; • a counting tool capable of incrementing, for each unique identifier identified, the number of coded responses associated with that unique identifier for each detection phase, including a memory space to store the increments; • A microprocessor capable of performing at least one operation on the increments of the memory space to deduce whether said unique identifier identified corresponds to a mounted rolling assembly of the vehicle and place it in a dedicated list.

[0035] Optionally, the identification system's reading device is capable of identifying at least one quantity of the received electrical signal for each coded response. The identification system includes a memory space capable of storing, for each unique identifier identified, for each coded response associated with that unique identifier, and for each detection phase, at least one quantity of the received electrical signal. Finally, the microprocessor is capable of performing at least one operation on the data in the memory space to determine whether at least one unique identifier of each radio frequency transponder is rolling by comparing the data between the first and second detection phases and placing said unique identifier in the dedicated list.

[0036] 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.

[0037] 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.

[0038] 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, then the unique identifiers and the number of coded responses per detection phase, and optionally the values ​​of the received electrical signal, must be transmitted outside the vehicle via specific communication means. The list of the vehicle's unique rolling stock identifiers 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.It should be noted that 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.

[0039] 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 detected at least one unique identifier, provides information on the location of this at least one unique identifier on the vehicle.

[0040] Regardless of how the system is embedded in the vehicle, whether partially or fully integrated, the system and the process implemented by this system are operational while the vehicle is in motion. Optionally, a The parameters must be adapted according to the vehicle's operating mode to improve their efficiency. Brief description of the drawings

[0041] 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

[0042] 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.

[0043] 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.

[0044] 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-l, 21a-2, 21b-l, 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.

[0045] 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 radio frequency antennas 32a and 32b. The radio communication system 31 includes An electrical signal transmission and reading system is installed in 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 (here located at the front of vehicle 2) from the passenger compartment. This system 31 therefore includes both the electrical signal transmitter and the electrical signal demodulator. In this particular case, system 31 also includes the electrical signal reading device.

[0046] 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.

[0047] 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.

[0048] 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. This 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 and radiating section 32a-2 of the bidirectional communication cable 32a is facilitated compared to that of section 32a-1 where the axis is directional, generating a movement angular of the assembly mounted in a turn, for example. These two continuous, radiating sections 32a-1 and 32a-2 are here disjointed and each only allows communication with one mounted 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 section 32a-2 located near the cavity 21a-2 would allow communication with the various dual mounted assemblies located on the same axle and on the same side of the vehicle 2. And, it is entirely conceivable that between the two sections 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.

[0049] 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 with 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.

[0050] Fig. 2 presents a synoptic diagram of the method for identifying the rolling assembly units of a vehicle.

[0051] This method comprises two main distinct phases. A first family of phases, referenced 2001a and 2001b, corresponds to the phases of detecting radio frequency transponders through the vehicle identification system. The first phase, 2001a, of the method is implemented when the vehicle is stationary, such as when parked, at a red light, or at a stop sign. The second phase, 2001b, of the method is implemented when the vehicle is moving. These detection phases, 2001a and 2001b, include a first step, 1001a and 1001b, which emits interrogation electromagnetic waves through the vehicle identification system. This step aims to generate electromagnetic waves through the vehicle's radiating antennas; This involves generating and modulating an electrical signal centered on a communication frequency F0 of radio frequency transponders.The signal requests the interrogation of a specific memory space in the radio frequency transponder containing a unique identifier. These detection phases 2001-a, 2001- . b can take place in any order as long as both are carried out.

[0052] In response to this interrogation signal, the radio frequency transponder emits a backscattered signal from the received electromagnetic waves containing the requested unique identifier.

[0053] The second step of these detection phases of process 1002a, 1002b 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.

[0054] 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.

[0055] 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 different radio frequency transponders for each detection phase 2001-a, 2001-b. 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, for each detection phase.

[0056] Next, the analysis phase 2002 includes a step 1004 for determining the information of each coded response. Specifically, the unique identifier associated with the radio frequency transponder is extracted from each coded response. Optionally, electrical signal parameters such as the electrical signal strength, known as RSSI (Received Signal Strength Indicator), or the phase between the signal received by backscattering and the electrical signal emitted by the identification system, are extracted from each coded response. These two electrical signal parameters can also be used to distinguish radio frequency transponders from the vehicle's rolling stock.

[0057] The next step 1005 of the second phase 2002 consists of evaluating the read rate of a unique identifier for each of the detection phases 2001-a, 2001-b. The read rate corresponds to the number of coded responses identified during a detection phase, which is normalized to a specific unit of time. This unit of specific time is the same for evaluating the read rate of each detection phase.

[0058] Optionally, if quantities have been extracted from the electrical signal of each coded response, step 1005 also consists of evaluating one or more quantities of the electrical signal with respect to a reference quantity. The measurand of these quantities can be the amplitude of the electrical signal or the phase difference between the received electrical signal and the emitted electrical signal. The metric of this reference quantity can be the mean or the median of the quantity for all coded responses with the same unique identifier. If the number of coded responses with the same unique identifier is large, the metric can be an indicator of the dispersion of the quantities, such as the standard deviation or the population variance of the quantities of the coded responses with the same unique identifier. This evaluation of the quantities is then to be performed on each coded response of each detection phase.Analyzing the dispersion of these quantities, particularly between the two detection phases, allows us to determine whether a unique identifier of a radio frequency transponder is placed on a moving assembly or on a fixed object of the vehicle. Indeed, no significant difference will be observed in the dispersion of the electrical signal quantities if the radio frequency transponder is placed on a fixed object of the vehicle between the vehicle's "stationary" and "moving" modes.

[0059] In step 1006, the two read rates between detection phases 2001a and 2001b are compared for the same unique identifier. If the two read rates are close or equal, this means that the radio frequency transponder associated with this unique identifier is located on a fixed object of the vehicle. Indeed, the vehicle's movement does not alter the read rate of the unique identifier, which indicates that the geographic positioning of the radio frequency transponder relative to the radio frequency antenna(s) remains unchanged, a characteristic of a fixed object of the vehicle on which the radio frequency antenna(s) are mounted.

[0060] Conversely, if the comparison of the read rates between the two detection methods 2001-a and 2001-b for the same unique identifier reveals a substantial difference, this means that the corresponding unique identifier is associated with a radio frequency transponder mounted on a moving object relative to the vehicle as a mounted unit. It is then necessary to place the unique identifier in a specific list of potential mobile mounted units.

[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 for example due to an overtaking or crossing between said vehicles or parking next to each other of the two vehicles.

[0062] Therefore, optionally, one or more iterations of the detection phases 2001a, 2001-b and the associated analysis phase 2002 should be repeated to determine whether the unique identifier(s) captured and placed in the specific list 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 the powertrain ignition being switched off. Preferably, only the vehicle operation detection phase 2001-b should be repeated.

[0063] These successive iterations are shown 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 1007 of the analysis phase 2002 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 1008. If only one iteration is performed, there is uniqueness between the specific list of unique identifiers resulting from step 1006 and the final group of the vehicle's rolling assemblies resulting from step 1007.

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

[0065] The mounted assembly 40a-1 is more particularly adapted for insertion into the respective cavity 21a-l. Mounted assemblies adapted for insertion into other respective cavities 21a-2, 21b-l, 21b-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 1800-6c.

[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 of its chip) or an identifier of an element of the assembled assembly 40a-1, for example of its rim or, preferably, of 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 correspond to the control of the detection phase, and in particular to launch the detection phase according to the driving conditions and trigger an analysis phase or if the detection phase must to be maintained. This includes verifying that a sufficient number of responses have been received. To do this, the values ​​provided by 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 on 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 driving in a straight line and / or driving at a constant speed under similar weather conditions. "Driving at a constant speed" means that the vehicle travels within a speed range around an average speed, the limits of which are no more than 3 m / s away from the average speed and for which the average speed is less than 30 m / s. Similarly, driving in a straight line 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 several axle-mounted assemblies 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 sidewall structure. This tag is equipped with a helical radio frequency antenna coupled to an electronic chip. The electronic chip includes a memory space in which the identifier is stored. The SGTIN-96 of the tire casing represents a unique identifier for the tire and, consequently, for the radio frequency transponder placed on it. Furthermore, the vehicle also includes fixed objects within the vehicle that contain a radio frequency transponder also operating at the communication frequency.

[0105] We will analyze the results of a radio frequency transponder of a mounted rolling assembly 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 the process, two phases of detection of the vehicle's radio frequency transponders will be carried out. These radio frequency transponder detection phases will be initiated through a system shown in Figures 1 and 4 above. The first phase is performed while the vehicle is stationary, here parked in a parking lot. The second detection phase is performed while the vehicle is moving. The results of the analysis phase for a single radio frequency transponder per category are illustrated in [Fig. 5].

[0107] For each category, when the vehicle is in motion, a population of coded responses is observed, distributed around a mean or median value. The population distribution is illustrated by the height of the vertical segment delimited by horizontal lines. Within each population, the rectangular shape represents the density of the population of coded responses around the mean value, this rectangle including more than 80% of the coded response population. The unit chosen for the responses is the read rate. Conversely, when the vehicle is stationary, the read rate is stable over time, which is logical since the vehicle assembly has not moved angularly during the detection phase. The same is true for the transponder of the stationary category.However, the read rate may change between two iterations of the detection phase at standstill 2001-a if the azimuthal position of the transponder in the mounted assembly has changed between the two iterations.

[0108] On the right side of the graph, the population of responses for an object in the "Fixed" category is visualized. It can be observed that the level of responses is homogeneous between the two detection phases, which indicates that the position of the radio frequency transponder has changed little between the two operating conditions of the vehicle.

[0109] In conclusion, the comparison of the read rates of this category of radio frequency transponder population shows little or no difference between the two operating conditions of the vehicle, which shows that the transponder is indeed fixed in the vehicle.

[0110] On the left side of the figure, the population of responses for an object in the "Turning" category is visualized. It can be observed that the reading rate changes significantly between the two vehicle operating conditions. In particular, the condition The vehicle's "stationary" read rate is lower than that of the "moving" condition. Furthermore, the stationary read rate is significantly lower than the moving read rate range, which is explained by the geographic coverage of the identification system's radio frequency antenna, which does not cover the entire tire. The low stationary read rate is due to the azimuth of this transponder within the tire when the vehicle is "stationary."

[0111] In conclusion, the analysis of the dispersion of reading rates between the "stopped" and "moving" conditions of the vehicle makes it easy to distinguish whether a radio frequency transponder is located on a rotating mounted assembly of the vehicle or on a fixed object 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: Initiate a first detection phase (2001-a) when the vehicle is stationary, comprising the following steps: • Initiate a first radio frequency interrogation step (1001-a) of at least one memory space of the radio frequency transponders communicating in backscatter containing at least one unique identifier for a duration Tl; • To receive (1002-a), via at least one radio frequency antenna, for the duration Tl, radio waves backscattered by radio frequency transponders communicating in backscattering; Launch a second detection phase (2001-b) during vehicle movement, comprising the following steps: • Launch a second radio frequency interrogation step (1001-b) of at least one memory space of the radio frequency transponders communicating in backscatter containing at least one unique identifier for a duration T2; • Receive (1002-b), via at least one radio frequency antenna, for the duration T2, radio waves backscattered by radio frequency transponders communicating in backscatter; Launch an analysis phase (2002) after the detection phases (2001-a, 2001-b) 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 for each coded response via a reading device (314); • For each determined unique identifier, evaluate a number of received signals containing said determined unique identifier (1005) for each detection phase (2001-a, 2001-b); • Define a read rate for each detection phase for each determined unique identifier and • Based on the comparison (1006) of the defined read rates between the two detection phases for the same determined unique identifier, deduce whether said determined unique identifier corresponds to a rolling assembly of the vehicle and then place the determined unique identifier of a rotating assembly in a specific memory space.

2. Method for identifying the rolling assembly units of a vehicle according to claim 1 wherein each duration of the radio frequency interrogation steps (1001-a, 1001-b) is greater than 30 milliseconds, preferably 40 milliseconds.

3. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 2 wherein, knowing the rolling speed V of the vehicle, the duration T2 of the second detection phase is greater than two wheel rotations of the vehicle assembly having the largest diameter.

4. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 3 wherein the rolling of the vehicle at the time of the second detection phase (2001-b) is carried out in a straight line.

5. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 4 wherein the vehicle is rolling at the time of the second detection phase (2001) at a constant speed.

6. A method for identifying the rolling assembly components of a vehicle according to any one of claims 1 to 4, wherein the rolling of the vehicle at the time of the second detection phase (2001) is carried out under the same meteorological conditions as the first detection phase.

7. Method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 6 wherein at least one unique identifier is an SGTIN identifier associated with one of the components of the assembly unit.

8. A method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 7 wherein, during said analysis phase (2002), for each coded response, determination of at least one quantity of the electrical signal associated with the coded response, and for each unique identifier determined and for each of the at least two detection phases (2001-a, 2001-b), determination of a set of quantities of the corresponding electrical signal; and wherein said deduction of whether a unique identifier determined corresponds to a rolling assembly of the vehicle is also based on an evaluation of the dispersion of said quantities in said assemblies by comparison between the quantities corresponding to each of the first and second detection phases.

9. A method for identifying the rolling assembly units of a vehicle according to claim 8, wherein said quantity of the electrical signal associated with the coded response is based on a measurand included in the group comprising an amplitude of the electrical signal, a phase of the electrical signal received relative to an electrical signal emitted by the radio communication system.

10. A method for identifying the rolling assembly units of a vehicle according to any one of claims 8 to 9 wherein said dispersion is evaluated according to a metric included in the group comprising a mean value, a median value, a standard deviation and a variance.

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 phases (2001-a, 2001-b) and analysis phase (2002) during vehicle movement is repeated N times, N being an integer greater than or equal to two, the method comprising a step of comparing lists (1007) of the unique identifiers of the rolling assembly components consisting at each analysis step, and the process includes the construction and storage in a dedicated memory space of the final group (1008) of the unique identifiers of the rolling vehicle assemblies as being that of the unique identifiers of the rolling vehicle assemblies common to the set of N lists resulting from the comparison step of the N lists (1007).

12. A method for identifying the rolling assembly units of a vehicle according to any one of claims 1 to 11 in which two successive detection phases 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:

14. • a radio communication transmitter / receiver system (311), comprising an electrical signal generator at a center frequency FO, 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; • A counting tool capable of incrementing, for each unique identifier identified, the number of coded responses associated with that unique identifier for each detection phase, including a memory space to store the increments; • A microprocessor (315) capable of performing at least one operation on the increments of the memory space to deduce whether said unique identifier identified corresponds to a mounted rolling assembly of the vehicle. Identification system (3) for the rolling assembly units 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-1, 21a-2, 21b-1, 21b-2) comprising at least one assembly mounted (41a-l) rolling located at an axial end of a vehicle axle.

15. 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.

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