FR3097709A1 - Identification and recognition procedures for transceiver modules in a motor vehicle - Google Patents

Abstract

Methods of identifying and recognizing a set of communicating modules in a motor vehicle, this set comprising a master module (4) and a plurality of satellite modules (5) UHF-SHF transceivers. These methods implement an identification database comprising radio fingerprints identifying the satellite modules (5), as well as a position identifier of the satellite modules (5). Figure for the abstract: Fig. 1

Description

Methods for identifying and recognizing transceiver modules in a motor vehicle

The invention relates to the automotive field and relates more particularly to the management of a set of communicating modules, this set comprising a master module and a plurality of transmitter-receiver satellite modules.

Such sets of communicating modules are commonly used in motor vehicles and for example in vehicles equipped with a passive access device. In such a passive access device, the locking or unlocking of the doors of the vehicle is controlled by the distance or the approach of the user who carries a transmitter device on him. A plurality of satellite modules are arranged at different locations in the vehicle and transmit to the master module information relating to the detection of the transmitter device carried by the user and to the position of this transmitter device. This information allows the master module to know the position of the user in relation to the vehicle and to order the locking or unlocking of the vehicle accordingly.

In known vehicles, the sets of communicating modules generally consist of satellite modules each connected to the master module by a wired bus. The master module thus has as many input connectors as there are satellite modules present in the vehicle. The master module identifies the information entering through a given connector to the satellite module which is connected to this connector.

This type of known architecture requires the use of electric cables connecting each of the satellite modules to the master module, which represents a significant length of cable, in particular when the vehicle comprises numerous satellite modules. These electrical cables and the associated input connectors on the master module represent a significant cost for this type of device. Furthermore, the necessary standardization implemented in the automotive field then requires sizing the master module with a number of input connectors corresponding to the maximum number of satellite modules that can be connected to it. Thus, such a connector will be oversized on all vehicles using a number of satellite modules less than the maximum number allowed by the master module, which still represents an additional cost. Conversely, the fact of providing a number of master module connectors optimized for each vehicle leads to the obligation to design a different module for each vehicle model and excludes the possibility of standardizing the master module.

Other known architectures of sets of communicating modules propose to connect the satellite modules to the master module by radio waves. This arrangement is particularly advantageous in the case where the satellite modules are already transceiver modules as in the passive access devices described above. However, in these known architectures, the master module must be able to identify which satellite module each radio signal that it receives comes from, and more precisely where this satellite module is located within the vehicle. To this end, the satellite modules are associated in hardware or software manner with their mounting position within the vehicle. The satellite modules are therefore different from each other and are not interchangeable. The satellite modules can be materially different, which excludes the standardization of the satellite modules and which leads to managing as many references as there are satellite modules within the same vehicle, which is not compatible with the standards of current automotive production. . As a variant, the satellite modules can be different in terms of their programming, which makes their standardization possible but which requires a programming step prior to assembly in the vehicle. This programming step represents an additional cost in the production of large series and also represents a risk of programming error.

The aim of the invention is to improve the methods relating to sets of communicating modules of the prior art.

To this end, the invention relates to a method for identifying a set of communicating modules in a motor vehicle, this set comprising a master module and a plurality of UHF-SHF transceiver satellite modules, these satellite modules all being identical . This process comprises the following steps:
- Arrange each satellite module in the vehicle at a predetermined position;
- determining an identification radio fingerprint for each satellite module, the identification radio fingerprint of a satellite module being made up of a plurality of values representative of a received radio signal power for each of the other satellite modules, this step comprising at least one sequence where a satellite module is activated in transmitter mode while at least one other satellite module is activated in receiver mode;
- storing the identification radio fingerprints of all the satellite modules of the vehicle in an identification database within the master module, this identification database assigning to each identification radio fingerprint of a satellite module a position identifier corresponding to the predetermined position of said satellite module.

Another object of the invention relates to a method for recognizing a set of communicating modules in a motor vehicle, this set comprising a master module and a plurality of UHF-SHF transceiver satellite modules arranged at a predetermined position in the vehicle. , the satellite modules being all identical, the master module having an identification database comprising as many identification radio fingerprints as there are satellite modules and assigning to each of these identification radio fingerprints a corresponding position identifier at a predetermined satellite module position. This process comprises the following steps, for each satellite module:
- perform a transmission sequence in which at least one satellite module is activated in transmitter mode while at least one other satellite module is activated in receiver mode;
- determining a radio footprint of the satellite module, the radio footprint of the satellite module being made up of a plurality of values representative of a received radio signal power for each of the other satellite modules;
- identifying this radio fingerprint with one of the identification radio fingerprints of the identification database and determining the position identifier which is assigned to this identification radio fingerprint;
- assign this position identifier to the satellite module concerned.

Another object of the invention relates to a method for implementing a set of communicating modules in a motor vehicle, this set comprising a master module and a plurality of satellite modules transmitting and receiving radio waves, a position identifier being assigned to each satellite module, this method comprising the following steps:
- each satellite module transmits a signal to the master module;
- the master module associates each signal received from a satellite module with the position identifier of this satellite module.

Another object of the invention relates to a set of motor vehicle communicating modules, this set comprising a master module and a plurality of satellite modules transmitting and receiving radio waves. The master module is adapted to the implementation of the recognition method as described above, and comprises an identification database comprising as many radioelectric identification fingerprints as satellite modules and assigning to each of these fingerprints radio identification a position identifier corresponding to a predetermined position of the satellite module in the vehicle.

In the present description and in the claims, the expression “UHF-SHF transceiver module” designates a radioelectric wave transceiver module capable of transmitting and receiving radioelectric signals at a frequency included in the UHF radiofrequency band ( "Ultra High Frequency", in English) or in the SHF frequency band ("Super High Frequency", in English). The UHF radio frequency band is the band of the radio spectrum between 300 MHz and 3 GHz and the SHF radio frequency band is the band of the radio spectrum between 3 GHz and 30 GHz. A UHF-SHF transceiver module is therefore suitable for transmitting and receiving at a frequency between 300 MHz and 30 GHz. Such UHF-SHF modules can for example be modules conforming to the Bluetooth standard or to the Wi-Fi standard.

In the methods according to the invention, the satellite modules and the master module do not require a specific wired bus between each satellite module and the master module. The costs associated with the electrical cables and associated input connectors of the prior art are thus eliminated. These methods allow in particular communication only by radio waves between the master module and the satellite modules.

All satellite modules, when mounted on the vehicle, are identical to each other. The satellite modules can therefore be standardized and implemented regardless of the mounting vehicle and regardless of their number. The master module can also be standardized for different vehicles with a different number of satellite modules.

The identification process allows automatic determination of the identification radio fingerprints of each satellite module without resorting to manual programming and without any risk of error. The recognition process is complementary to the identification process and allows the master module to obtain the position identifier of each of the satellite modules also automatically and without risk of error.

The implementation method allows communication between the satellite modules and the master module by allowing the latter to know the position within the vehicle of each satellite module thanks to the position identifier which has been assigned to it.

The maintenance of the system is facilitated because the replacement of one of the satellite modules by another identical satellite module simply requires implementing the recognition method again so that the new satellite module is automatically identified.

The identification method may comprise the following additional characteristics, alone or in combination:
- The method is initialized by a command transmitted by a digital diagnostic socket of the vehicle, the master module being connected to a digital on-board network of the vehicle;
- the method comprises a preliminary step of storing in the master module the hardware address of each satellite module;
- the method includes an initialization step where the master module randomly generates a unique identifier for each satellite module;
- each satellite module randomly generates a unique identifier specific to it, and when a satellite module is in transmitter mode, this satellite module jointly transmits this unique identifier;
- the master module and the satellite modules are interconnected by a digital on-board network of the vehicle;
- The master module is a radio wave transmitter-receiver module, the master module and the satellite modules being interconnected by radio waves;
- the step of determining a radioelectric identification fingerprint for each satellite module comprises, for each satellite module, a sequence where this satellite module is activated in transmitter mode while all the other satellite modules are activated in receiver mode, the fingerprint radio frequency identification of a satellite module consisting of values representative of the radio signal power received by each of the other satellite modules;
- the step of determining a radioelectric identification fingerprint for each satellite module comprises, for each satellite module, a sequence where this satellite module is activated in receiver mode while all the other satellite modules are activated in transmitter mode, the fingerprint radio frequency identification of a satellite module consisting of values representative of the power of the radio signals that it receives from all the other satellite modules;
the step of determining an identification radio fingerprint for each satellite module comprises a sequence in which each satellite module which has been activated in receiver mode transmits to the master module a value representative of the power of the radio signals received;
- when a satellite module is activated in transmitter mode, it transmits a signal at constant power for a predetermined duration;
- said predetermined duration is from 5 to 30 seconds;
- the satellite modules are adapted to the Bluetooth standard, the activation of a satellite module in transmitter mode corresponding to the "Advertising" mode of the Bluetooth standard, and the activation of a satellite module in receiver mode corresponding to the "Scanning" mode » of the Bluetooth standard;
- each of said values representative of a received radioelectric signal power is the median value of the indications of intensity of the signal received by the satellite module during the time when it is activated in receiver mode.

The recognition method may include the following additional features, alone or in combination:
- The method is initialized by a command transmitted by a digital diagnostic socket of the vehicle, the master module being connected to a digital on-board network of the vehicle;
- the method includes an initialization step where the master module randomly generates a unique identifier for each satellite module;
- each satellite module randomly generates a unique identifier specific to it, and when a satellite module is in transmitter mode, this satellite module jointly transmits this unique identifier;
- the master module and the satellite modules are interconnected by a digital on-board network of the vehicle;
- The master module is a radio wave transmitter-receiver module, the master module and the satellite modules being interconnected by radio waves;
the method comprises a preliminary step of listing the satellite modules in which the master module is in receiver mode and in which the master module activates all the satellite modules in transmitter mode;
- the step of performing a transmission sequence includes, for each satellite module, a sequence where this satellite module is activated in transmitter mode while all the other satellite modules are activated in receiver mode, the radio footprint of a module satellite consisting of values representative of the radio signal power received by each of the other satellite modules;
- the step of performing a transmission sequence comprises, for each satellite module, a sequence where this satellite module is activated in receiver mode while all the other satellite modules are activated in transmitter mode, the radio footprint of a module satellite consisting of values representative of the power of the radio signals that it receives from all the other satellite modules;
the step of determining a radio footprint of the satellite module comprises a sequence in which each satellite module which has been activated in receiver mode transmits to the master module a value representative of the power of the radio signals received;
- when a satellite module is activated in transmitter mode, it transmits a signal at constant power for a predetermined duration;
- said predetermined duration is from 5 to 30 seconds;
- the satellite modules are adapted to the Bluetooth standard, the activation of a satellite module in transmitter mode corresponding to the "Advertising" mode of the Bluetooth standard, and the activation of a satellite module in receiver mode corresponds to the "Scanning" mode » of the Bluetooth standard;
- each of said values representative of a received radioelectric signal power is the median value of the indications of intensity of the signal received by the satellite module during the time when it is activated in receiver mode;
- During the step of assigning this position identifier to the satellite module concerned, the position identifier of the satellite module is stored in the master module and is associated with a unique identifier of the satellite module;
- During the step of assigning this position identifier to the satellite module concerned, the position identifier of the satellite module is stored in this satellite module;
- for each satellite module, the position identifier is determined by the master module and is transmitted to the satellite module concerned via a communication network.

The method of implementation may comprise the following additional characteristics, alone or in combination:
- each satellite module stores its position identifier and transmits this position identifier when it is in transmitter mode;
- the position identifiers of all the satellite modules are stored in the master module and its each associated with a unique identifier of the corresponding satellite module;
- When receiving an external radio signal from a mobile terminal, each satellite module transmits to the master module a power signal which includes a value representative of the power of the signal that the satellite module receives.

Other characteristics and advantages of the invention will emerge from the description given of it below, by way of indication and in no way limiting, with reference to the appended drawings, in which:

FIG. 1 illustrates a motor vehicle equipped with a set of communicating modules according to the invention;

FIG. 2 illustrates the vehicle of FIG. 1 in a step of the identification method according to the invention;

FIG. 3 illustrates the vehicle of FIG. 1 in another step of the identification method according to the invention;

FIG. 4 illustrates the vehicle of FIG. 1 in a step of the recognition method according to the invention;

FIG. 5 illustrates the vehicle of FIG. 1 in another step of the recognition method according to the invention;

FIG. 6 illustrates the vehicle of FIG. 1 in another step of the recognition method according to the invention;

FIG. 7 illustrates the vehicle of FIG. 1 in a step of the implementation method according to the invention;

FIG. 8 illustrates the vehicle of FIG. 1 in another step of the implementation method according to the invention;

Figure 9 illustrates a second embodiment of the invention.

FIG. 1 schematically represents a motor vehicle 1 equipped with a set of communicating modules 4, 5. This example of communicating modules relates to a passive locking/unlocking device, also called “hands-free”, of the vehicle thanks to a mobile communication terminal of a user. This mobile communication terminal is, for example, a portable telephone 3 incorporating a “Bluetooth” standard transmitter.

In this example, vehicle 1 has door and trunk locks 2. The locking and unlocking of these locks is controlled by the distance or the proximity of the user carrying the Bluetooth 3 telephone.

The hands-free locking/unlocking device comprises a master module 4 and satellite modules 5. In this simplified example, four satellite modules 5 are provided: a right side module 5A, a left side module 5B, a roof module 5C, and a 5D rear module.

The master module 4 and the satellite modules 5 are electronic devices embedding a microcontroller as well as the programs making it possible to conventionally implement methods for detecting situations where the locking or unlocking of the vehicle is required. In the present example, all the modules 4.5 are equipped with BLE (Bluetooth Low Energy) transceiver means. This BLE communication technology has the advantage of low power consumption and a range compatible with the hands-free locking and unlocking function. In addition, this BLE technology makes it possible to use the user's Bluetooth mobile phone to detect its approach or its distance, which eliminates the utility of any other specific object such as key, badge or access card. However, BLE technology is inefficient for locating the user's Bluetooth phone 3 as well as for estimating the distance between the Bluetooth phone and vehicle 1. In practice, the more vehicle 1 has distributed satellite modules 5 at various points on its bodywork, the more precise the location of the Bluetooth 3 mobile phone (and therefore of the user). Although the simplified example described here concerns four satellite modules, it can be considered that six to twelve modules are necessary for correct operation of the locking/unlocking device.

When the Bluetooth mobile phone 3 is detected in the vicinity of the vehicle 1, each of the satellite modules 5 receives a signal emitted by the phone 3 then, each of these satellite modules 5 transmits to the master module 4 a signal indicating that the Bluetooth mobile phone 3 has been detected as well as a value representative of the power of the received signal. The master module 4 receives from each satellite module 5 an indication of the signal strength that this satellite module receives and, knowing the location of each satellite module within the vehicle, the master module 4 deduces therefrom the position of the Bluetooth mobile telephone 3. The methods for determining the distance between a terminal 3 and a vehicle from radio signals received by satellite modules are known per se and will not be described in more detail here.

The master module 4 is preferably connected to an on-board digital network of the vehicle 1 (the CAN network, for example) in order to be able in particular to act on the locks 2 of the vehicle 1.

The communication between the satellite modules 5 and the master module 4 is preferably done exclusively wirelessly by the Bluetooth protocols, which has the advantage of exempting the satellite modules from any physical connection apart from their power supply. As a variant, all the modules can be linked to an on-board digital network of the vehicle, such as the CAN network, and the communication between the master module and the satellite modules can transit over this network.

The satellite modules 5 are all identical to one another. The vehicle 1 is thus equipped with a single reference for the satellite modules 5 which are mounted on the vehicle at the four locations described. Although identical, the satellite modules 5 each have a network hardware address, such as a MAC address (“Media Access Control”, in English) or a Bluetooth address (“Bluetooth device address”, in English).

To allow the reception of all the information necessary for the master module 4, the latter must be able to identify which is the location of the satellite module which is the transmitter of a communication. To this end, an identification method is first implemented during the design of the vehicle 1, then a recognition method is implemented during the manufacture of the vehicle 1, and finally an implementation method concerns the normal operation of vehicle 1 once produced.

Figures 2 and 3 illustrate an identification process that is implemented when preparing for the production launch of a new vehicle model. For this identification process, a first vehicle (or prototype) of the vehicle model whose production is about to be launched is used in order to determine the radioelectric identification fingerprints for each of the satellite modules positioned in the vehicle, these radioelectric fingerprints of identification therefore depending in particular on the particular conformation of the vehicle model concerned.

The satellite modules 5 are first mounted in the vehicle in their respective places. In the present example, the satellite modules 5A, 5B of the right and left sides are fixed for example inside the doors of the vehicle, the roof satellite module 5C is fixed under the ceiling of the vehicle while the rear satellite module 5D is fixed inside the door of the trunk of the vehicle 1. The master module 4 is also fixed in its housing, for example here in the on-board console of the vehicle 1. This configuration, with the modules 4.5 fixed in their place , is the one that will be adopted by all vehicles of this model.

The master module 4 is then connected to the CAN network of the vehicle 1. The satellite modules 5 are simply fixed in their respective places and do not require any communication link. Computer equipment 6 is connected to the master module 4, directly or via the CAN network. This equipment 6 can for example be connected to an on-board diagnostic socket, such as an OBD socket (“On Board Diagnostic”, in English) and allows, by communicating with the master module 4, to activate the different sequences of the identification process.

In a preliminary step, one proceeds via the equipment 6 to a storage operation in the master module 4 of the peripheral hardware address (here, the Bluetooth address) of each satellite module 5. In addition, or alternatively, the master module 4 randomly generates a unique identifier for each satellite module 5, or even each satellite module 5 randomly generates a unique identifier of its own, this unique identifier being transmitted when the satellite module 5 is in transmitter mode. These steps allow the master module 4 to be able to address or recognize the transmissions of a particular satellite module 5.

The master module 4 then switches to a mode called "identification mode". This mode follows a program previously loaded into a memory of the master module 4. In this step, each module is identified by a unique network address (its Bluetooth address, for example) and the position in the vehicle of each module thus identified is also known and communicated to the master module 4 by the equipment 6.

During this step, the master module 4 will control one of the satellite modules 5 in transmitter mode and all the other satellite modules 5 in receiver mode. In other words, in the present example with four satellite modules, there will be the following four successive transmission sequences:
- The right flank satellite module 5A is controlled in transmitter mode while the other satellite modules 5B, 5C, 5D are controlled in receiver mode;
- The left flank satellite module 5B is controlled in transmitter mode while the other satellite modules 5A, 5C, 5D are controlled in receiver mode;
- The roof satellite module 5C is controlled in transmitter mode while the other satellite modules 5A, 5B, 5D are controlled in receiver mode;
- The rear satellite module 5D is controlled in transmitter mode while the other satellite modules 5A, 5B, 5C are controlled in receiver mode.

In the present example relating to the BLE standard, the control of a satellite module 5 in transmitter mode corresponds to the activation of the mode called "Advertising", which causes radio waves to be transmitted in the Bluetooth standard every second and to constant power. Similarly, the command in receiver mode of the other satellite modules 5 corresponds to the activation of the “Scanning” mode of the BLE standard. In this mode, the satellite module 5 concerned receives the incoming BLE signals by measuring in particular the reception power of this signal. Since the BLE standard is documented, these “Advertising” and “Scanning” modes will not be described in more detail here.

The duration of each transmission sequence (relative to each satellite module 5) is preferably between 5 and 30 seconds, and is for example 20 seconds.

In the present example, the master module 4 will therefore first of all activate the right flank satellite module 5A in “Advertising” mode in the first transmission sequence. For this, the master module 4, which knows the peripheral hardware address of this satellite module 5A, sends an instruction via Bluetooth to this satellite module to activate it in “Advertising” mode. The master module 4 also transmits via Bluetooth an instruction to each of the other satellite modules 5B, 5C, 5D (thanks to their hardware addresses) to switch to “Scanning” mode. Each of the satellite modules 5B, 5C, 5D in "Scanning" mode receives the signal emitted by the satellite module 5A, which is in "Advertising" mode, with a constant power corresponding to the transmission power of the satellite module 5A lowered by the attenuation corresponding to the position of the receiver satellite module relative to the transmitter satellite module and to the configuration of the vehicle. For example, the satellite module 5A on the right side being in "Advertising" mode, this signal is received by each of the other satellite modules 5B, 5C, 5D with the following power (in the present example, the value representing a power received by the satellite module is the attenuation in dB of the received signal):
- The left flank satellite module 5B receives the signal with a power of -101 dB;
- the roof satellite module 5C receives the signal with a power of -70 dB;
- the rear 5D satellite module receives the signal with a power of -55 dB.

This set of signal reception powers is specific to the satellite module 5A in its positioning within the vehicle. This set of three power values therefore constitutes a unique radio fingerprint making it possible to identify the satellite module 5A which is in transmitter mode.

The value representative of a received radio signal power may for example be the median of the RSSI (“Received Signal Strength Indication”) over the duration of the sequence, here 20 seconds.

Following this first transmission sequence, the master module 4 starts a second transmission sequence targeting a second satellite module, for example the satellite module 5B on the left flank, by controlling this module in "Advertising" mode and all the other modules satellites in “Scanning” mode. and the reception power values are also stored by the module 4, for all the satellite modules in “Scanning” mode.

Such a transmission sequence is also carried out in succession for each of the other satellite modules 5, until all the transmission sequences have been carried out (as many transmission sequences as there are satellite modules 5).

With reference to FIG. 3, each satellite module 5 transmits to the master module 4 all the reception power values of the signals that this satellite module has received in “Scanning” mode. The master module 4 stores these reception power values and constitutes a database listing the radioelectric identification fingerprint of each of the satellite modules 5 and attributing to each of these fingerprints the position identifier of the corresponding module.

Following the example described, the table below schematically illustrates the identification database that was developed by the master module 4.

The position identifier given as an example in the table above is a simplified two-letter code indicating the position of the satellite module. As a variant, the position identifier can be any value allowing the master module to identify the position of the satellite module, such as for example the coordinates of the satellite module.

This identification process thus leads to the creation of an identification database making it possible, from a radio fingerprint, to assign this fingerprint to a position of satellite module 5 within the vehicle 1. This database identification data is saved in order to produce master modules 4 in series for that particular vehicle model.

Thus, during mass production of the vehicle model corresponding to the prototype used for the identification process, these vehicles will each receive a master module 4 which includes in memory the identification database specific to this vehicle model. The 5 satellite modules fitted to the entire series of this vehicle model are all identical to each other and do not require any specific programming for their positioning in the vehicle.

During mass production of vehicles, the modules 4.5 are fixed in their respective places on each vehicle. At the end of the assembly line, or at least at the end of the assembly of all the elements which could influence the radioelectric identification fingerprints, a recognition process is implemented to allow the master module 4 of the vehicle to identify each of the vehicle's 5 satellite modules with their respective locations.

Figures 4 to 6 illustrate the recognition process which is thus implemented to finalize the production of a vehicle.

This recognition process can, for example, be launched at the appropriate time at the end of the production line by sending a command to launch the program corresponding to this recognition process to the master module 4 on the OBD socket of the vehicle.

In a preliminary step of listing the satellite modules, illustrated in FIG. 4, the master module is in receiver mode and it activates all the satellite modules in transmitter mode. This step allows the master module 4 to list the satellite modules present in the vehicle. Indeed, the master module 4 does not know the hardware addresses or any other identifier relating to the satellite modules 5 which have been mounted in the vehicle 1. At this stage, the master module 4 therefore sends the instruction to switch to transmitter mode to all 5 satellite modules within range. When all the satellite modules 5 switch to transmitter mode, for example in “Advertising” mode or any other mode allowing the satellite modules 5 to communicate their hardware address, the master module 4 memorizes the list of hardware addresses (such as Bluetooth addresses) of all satellite modules 5.

In addition, or alternatively, the master module 4 randomly generates a unique identifier for each satellite module 5 in transmitter mode, or even each satellite module 5 randomly generates a unique identifier of its own, this unique identifier being transmitted to the master module 4 during this transmitter mode.

This preliminary census step allows the master module 4 to be able to address or recognize the transmissions of a particular satellite module 5. The satellite module 4 thus has the list of the satellite modules 5 present in the vehicle 1 and is able to identify them, although it does not yet know the position of these satellite modules 5 within the vehicle.

The master module 4 then performs, for each of the satellite modules 5, a transmission sequence in which the satellite module 5 concerned is controlled in transmitter mode (for example, as previously, in “Advertising” mode of the BLE standard) while all the other satellite modules 5 will be controlled in receiver mode (according to the same example, in “Scanning” mode of the BLE standard). The first satellite module 5 to be the subject of a transmission sequence, as well as the order of the transmission sequences, can be chosen randomly by the master module 4.

These emission sequences correspond to those carried out during the identification process implemented for this vehicle model. In the present example, the transmission sequences therefore last 20 seconds and the value representing a received radio signal power for each satellite module 5 is the median of the RSSI over these 20 seconds.

FIG. 5 illustrates the first of these sequences which starts, for example, with the right flank satellite module 5A. This module 5A is therefore in “Advertising” mode while the other modules 5B, 5C, 5D are in “Scanning” mode and measure the power of the signals that they each receive.

The same sequence is then carried out in turn for each of the satellite modules 5, the satellite module concerned being controlled in “Advertising” mode while all the other modules are controlled in “Scanning” mode.

Referring to Figure 6, each of the satellite modules 5 will transmit, via Bluetooth in this example, to the master module 4 the power values of the signals it has received for each satellite module 5 in "Advertising" mode. Thus, for each transmission sequence where one of the satellite modules 5 is in transmitter mode, the master module 4 receives three different signal power values received by the three other satellite modules 5. These three received signal power values constitute a radio footprint specific to satellite module 5A which was in “Advertising” mode. The master module 4 will compare these radio fingerprints with the radio fingerprint identification it has in the identification database. Each radio fingerprint that is recorded here at the end of the transmission sequences corresponds to one of the radio fingerprints of identification in the identification database. For each satellite module 5, the master module 4 will therefore identify which radioelectric identification fingerprint corresponds to the satellite module and will therefore define which is the position identifier which corresponds to this satellite module, from the database of identification.

The module 4 thus assigns the correct position identifier to each satellite module 5. This assignment can be done by association, within the master module 4, of the hardware address of a satellite module 5 with its position identifier. Alternatively, the position identifier is assigned to a satellite module directly in the satellite module itself. For example, the master module 4 transmits its position identifier to the satellite module concerned and this satellite module stores this position identifier. During future transmission phases, the satellite module will send its position identifier in addition to the information transmitted.

At the exit of the chain, thanks to the recognition process, the vehicle 1 is therefore delivered with a set of operational communicating modules because all the satellite modules 5 are mounted in the vehicle at their respective position, and the master module 4 is able to know the position of each satellite module which transmits information to it.

Figures 7 and 8 illustrate a method of implementing this set of communicating modules intended for hands-free locking/unlocking of a vehicle produced as described previously.

In such a vehicle in service, the user is provided with his Bluetooth mobile telephone which is configured to emit a signal indicating to the vehicle the approach of the user or the distance from the user. The signals emitted by the mobile telephone 3 constitute an external radio signal for the vehicle. In the schematic example of Figure 7, the user's Bluetooth mobile phone 3 emits a Bluetooth signal which is picked up by all the satellite modules 5. Each satellite module 5 will pick up the signal emitted by the phone 3 with a power received which depends on the distance between telephone 3 and each module 5.

Each of the satellite modules 5 will then communicate to the master module 4 (see figure 8) the power of the signal received from the telephone 3. The master module 4 receiving this information also has the position identifier for each satellite module 5. The master module 4 will then have the signal power received by each of the satellite modules 5 knowing the position of each of these satellite modules 5 and will be able to determine, in a conventional manner, the position of the mobile telephone 3.

Furthermore, during a maintenance operation, one of the satellite modules 5 may require replacement, due to failure for example. The defective satellite module 5 is then simply replaced by another identical satellite module 5, of the same reference, and which is not specific to a particular position within the vehicle. Once the replacement satellite module has been substituted for the defective satellite module, the recognition process described above is again implemented, so that the position identifier corresponding to the new satellite module is automatically assigned to it.

Figure 9 illustrates a second embodiment of the identification and recognition methods described above. This second embodiment is identical to the first embodiment except for the constitution of the radioelectric identification fingerprint. In this second embodiment, the radioelectric identification fingerprint of a satellite module 5 consists of the power values received by this satellite module in receiver mode, when all the other satellite modules 5 are in transmitter mode.

In the identification method according to this second embodiment, after each satellite module 5 is placed in the vehicle, the master module 4 activates one of the satellite modules 5 in receiver mode (in the example illustrated in FIG. 9 , this is the right flank satellite module 5A) and activates all the other satellite modules 5B, 5C, 5D in transmitter mode. The right flank satellite module 5A then transmits to the master module 4 the three received signal power values corresponding to the three emissions from the other satellite modules 5B, 5C, 5D. This transmission sequence is repeated for the other satellite modules 5B, 5C, 5D in the same way and the master module 4 thus constitutes the identification database which therefore comprises, for each satellite module 5, a radioelectric identification fingerprint. constituted by the power values received by a satellite module 5 in receiver mode when all the other satellite modules are in transmitter mode.

Similarly, according to this second embodiment, the recognition method takes place in a manner similar to the first embodiment except that instead of activating a single satellite module in turn in transmitter mode while all the other satellite modes are in receiver mode, the master module 4 here activates a satellite module in receiver mode while all the other satellite modules are activated in transmitter mode.

Variants of the methods described can be implemented without departing from the scope of the invention. For example, the set of communicating modules can have another function in the vehicle such as an automatic tire pressure monitoring function (TPMS for “Tyre Pressure Monitoring System”, in English), the satellite modules then being pressure sensors housed in each of the tires of the vehicle and the master module being housed inside the passenger compartment of the vehicle or under the bonnet.

Also as a variant, the satellite modules can all be connected to the on-board digital network of the vehicle 1 (CAN network) and the communication between the satellite modules and the master module can be carried out exclusively through this network rather than being carried out by waves. radio. The satellite modules then transmit the values representative of a power received via the CAN network, as does the master module for sending instructions to the satellite modules, to activate them in transmitter or receiver mode, or to assign an identifier position to a satellite module.

Claims (20)

Method for identifying a set of communicating modules in a motor vehicle, this set comprising a master module (4) and a plurality of satellite modules (5) UHF-SHF transceivers, the satellite modules (5) all being identical , this method comprising the following steps:
- Arrange each satellite module (5) in the vehicle (1) at a predetermined position;
- determining an identification radio fingerprint for each satellite module (5), the identification radio fingerprint of a satellite module (5) consisting of a plurality of values representative of a received radio signal power for each other satellite modules (5), this step comprising at least one sequence where one satellite module (5) is activated in transmitter mode while at least one other satellite module (5) is activated in receiver mode;
- storing the radioelectric identification fingerprints of all the satellite modules (5) of the vehicle (1) in an identification database within the master module (4), this identification database assigning to each radioelectric fingerprint identification of a satellite module (5) a position identifier corresponding to the predetermined position of said satellite module (5). Method according to claim 1, characterized in that it comprises a preliminary step of storing in the master module (4) the hardware address of each satellite module (5). Method according to any one of the preceding claims, characterized in that it includes an initialization step where the master module (4) randomly generates a unique identifier for each satellite module (5). Method according to one of Claims 1 or 2, characterized in that each satellite module (5) randomly generates a unique identifier specific to it, and when a satellite module (5) is in transmitter mode, this satellite module (5 ) jointly issues this unique identifier. Method according to any one of the preceding claims, characterized in that the step of determining an identification radio fingerprint for each satellite module (5) comprises, for each satellite module (5), a sequence in which this satellite module (5 ) is activated in transmitter mode while all the other satellite modules (5) are activated in receiver mode, the radioelectric fingerprint for identifying a satellite module (5) consisting of values representative of the power received from the radioelectric signal by each of the other satellite modules (5). Method according to any one of Claims 1 to 4, characterized in that the step of determining an identification radio fingerprint for each satellite module (5) comprises, for each satellite module (5), a sequence in which this satellite module (5) is activated in receiver mode while all the other satellite modules (5) are activated in transmitter mode, the radioelectric fingerprint for identifying a satellite module (5) consisting of values representative of the power of the radioelectric signals it receives from all the other satellite modules (5). Method according to one of Claims 5 or 6, characterized in that the step of determining an identification radio fingerprint for each satellite module (5) comprises a sequence in which each satellite module (5) which has been activated in receiver mode transmits to the master module (4) a value representative of the power of the radio signals received. Method according to one of Claims 5 to 7, characterized in that the satellite modules (5) are adapted to the Bluetooth standard, the activation of a satellite module (5) in transmitter mode corresponding to the "Advertising" mode of the Bluetooth standard, and the activation of a satellite module (5) in receiver mode corresponding to the "Scanning" mode of the Bluetooth standard. Method for recognizing a set of communicating modules in a motor vehicle, this set comprising a master module (4) and a plurality of satellite modules (5) UHF-SHF transceivers arranged at a predetermined position in the vehicle (1) , the satellite modules (5) being all identical, the master module (4) having an identification database comprising as many radioelectric identification fingerprints as satellite modules (5) and assigning to each of these fingerprints radio identification a position identifier corresponding to a predetermined position of the satellite module (5), this method comprising the following steps, for each satellite module (5):
- performing a transmission sequence in which at least one satellite module (5) is activated in transmitter mode while at least one other satellite module (5) is activated in receiver mode;
- determining a radio footprint of the satellite module (5), the radio footprint of the satellite module (5) consisting of a plurality of values representative of a received radio signal power for each of the other satellite modules (5);
- identifying this radio fingerprint with one of the identification radio fingerprints of the identification database and determining the position identifier which is assigned to this identification radio fingerprint;
- allocating this position identifier to the satellite module (5) concerned. Method according to claim 9, characterized in that it includes an initialization step where the master module (4) randomly generates a unique identifier for each satellite module (5). Method according to one of Claims 9 or 10, characterized in that each satellite module (5) randomly generates a unique identifier specific to it, and when a satellite module (5) is in transmitter mode, this satellite module (5 ) jointly issues this unique identifier. Method according to one of Claims 9 to 11, characterized in that it comprises a preliminary step of listing the satellite modules (5) in which the master module (4) is in receiver mode and in which the master module (4) activates all satellite modules (5) in transmitter mode. Method according to one of Claims 9 to 12, characterized in that the step of carrying out a transmission sequence comprises, for each satellite module (5), a sequence in which this satellite module (5) is activated in transmitter mode while that all the other satellite modules (5) are activated in receiver mode, the radio footprint of a satellite module (5) being constituted by values representative of the radio signal power received by each of the other satellite modules (5). Method according to any one of Claims 9 to 12, characterized in that the step of carrying out a transmission sequence comprises, for each satellite module (5), a sequence in which this satellite module (5) is activated in receiver mode while all the other satellite modules (5) are activated in transmitter mode, the radio footprint of a satellite module (5) being made up of values representative of the power of the radio signals it receives from all the other satellite modules ( 5). Method according to one of Claims 13 or 14, characterized in that the step of determining a radio fingerprint of the satellite module (5) comprises a sequence in which each satellite module (5) which has been activated in receiver mode transmits to the master module (4) a value representative of the power of the radio signals received. Method according to one of Claims 13 to 15, characterized in that the satellite modules (5) are adapted to the Bluetooth standard, the activation of a satellite module (5) in transmitter mode corresponding to the "Advertising" mode of the Bluetooth standard, and the activation of a satellite module (5) in receiver mode corresponds to the "Scanning" mode of the Bluetooth standard. Method according to one of Claims 9 to 16, characterized in that, during the step of allocating this position identifier to the satellite module (5) concerned, the position identifier of the satellite module (5) is stored in the master module (4) and is associated with a unique identifier of the satellite module (5). Method according to one of Claims 9 to 16, characterized in that, during the step of allocating this position identifier to the satellite module (5) concerned, the position identifier of the satellite module (5) is stored in this satellite module (5). Method according to claim 18, characterized in that, for each satellite module (5), the position identifier is determined by the master module (4) and is transmitted to the satellite module (5) concerned via a communication network. Set of motor vehicle communicating modules, this set comprising a master module (4) and a plurality of satellite modules (5) UHF-SHF transceivers, characterized in that the master module (4) is adapted to the implementation of the recognition method according to one of Claims 9 to 19, and comprises an identification database comprising as many identification radio fingerprints as there are satellite modules (5) and assigning to each of these identification radio fingerprints a position identifier corresponding to a predetermined position of the satellite module (5) in the vehicle.