UWB communication between a vehicle system and a portable identifier

Abstract

The invention relates to a method for communication between a portable identifier and a vehicle system that has registered the portable identifier. The system and the identifier are configured to communicate using a UWB communication protocol in a first perimeter around the vehicle and to communicate using a BLE communication protocol in a second perimeter around the vehicle. The method comprises, while a user carrying the identifier approaches the vehicle: detecting (S10) that the identifier is located in the second perimeter, performing (S20) tests to trigger UWB communication, success of one of the tests performed leading to triggering (S30) of the communication, detecting (S40) that the identifier is located at a distance of less than or equal to a predetermined near distance, and modifying (S50) the communication in order to reduce the frequency of the UWB exchanges. The method provides improved communication between the identifier and the system.

Description

UWB communication between vehicle system and portable identifier

[0001] The present disclosure relates to a method of communication between a portable identifier and a vehicle system, a computer program for such a system and / or such a portable identifier, a storage medium for such a program, such a portable identifier and such a vehicle system. Technical background

[0002] Today, there are vehicles equipped with systems that have stored one or more portable identifiers. These portable identifiers can be portable devices such as key fobs or smartphones. Each identifier includes an electrical power source (e.g., a battery) that allows it to be portable. Such systems allow the vehicle to perform functions, such as opening the doors and / or starting the vehicle, based on the location of the one or more portable identifiers.

[0003] To perform these functions, each portable identifier may be configured to communicate using one or more communication protocols with the system. For example, the portable identifier and the system may be configured to communicate using a UWB (Ultra Wide Band) communication protocol and a BLE (Bluetooth Low Energy) communication protocol. However, the use of these one or more communication protocols reduces the lifetime of the portable identifier's electrical power source.

[0004] In particular, UWB communication typically involves periodic UWB exchanges. The handheld identifier's participation in these periodic UWB exchanges consumes a lot of its power source's lifetime.

[0005] There is therefore a need to improve communication between such a portable identifier and such a system. Summary

[0006] To this end, a method is proposed for communication between a portable identifier and a vehicle system having registered the portable identifier. The identifier comprises an electrical energy source. The system and the identifier are configured to communicate using a UWB communication protocol in a first perimeter around the vehicle and to communicate using a BLE communication protocol in a second perimeter around the vehicle. The second perimeter includes the first perimeter. The method comprises, while a user carrying the identifier approaches the vehicle, the following five steps. The first step is a first detection. The first detection is a detection that the identifier is located in the second perimeter. The second step is performed after the first detection. The second step is a performance of tests for triggering a communication using the UWB communication protocol.The tests performed are periodic according to a first period. The third step is a success of one of the tests performed, resulting in a triggering of the communication. The triggered communication includes periodic UWB exchanges according to a second period. The second period is shorter than the first period. The fourth step is a second detection. The second detection is a detection that the identifier is located at a distance less than or equal to a predetermined close distance. The fifth step is performed after the second detection. The fifth step is a modification of the communication so that the UWB exchanges are periodic according to a third period. The third period is shorter than the second period.

[0007] The method may further comprise a third detection. The third detection may be a detection that the identifier is located in the vehicle. The method may further comprise, after the third detection, modifying the communication so that the UWB exchanges are periodic according to a fourth period. The fourth period may be greater than the third period and / or shorter than the second period.

[0008] The method may further comprise, after ignition of the vehicle engine, suspending the communication, or modifying the communication so that the UWB exchanges are periodic according to a fifth period. The fifth period may be greater than the fourth period. Optionally, the fifth period may also be greater than the second period.

[0009] Optionally, the method may comprise, after suspension of the communication, re-engagement of the communication when the vehicle is traveling at a speed less than or equal to a predetermined speed limit.

[0010] The method may further comprise, after stopping the vehicle engine, when the communication is suspended, a re-engagement of the communication using the UWB communication protocol. The re-engaged communication may comprise periodic UWB exchanges according to the third period. The method may further comprise, after stopping the vehicle engine, when the communication comprises periodic UWB exchanges according to the fourth or fifth period, a modification of the communication so that the UWB exchanges are periodic according to the third period. The method may further comprise a fourth detection. The fourth detection may be a detection that the identifier is located at a distance greater than or equal to the predetermined close distance. The method may further comprise, after the fourth detection, a suspension of the re-engaged communication.

[0011] The first period can be a multiple of the second period. The second period can be a multiple of the third period. The fourth period can be a multiple of the third period.

[0012] The identifier may include a microcontroller, a BLE component, and a UWB component. Initiating communication may include sending a wake-up signal from the microcontroller to the UWB component. The BLE component may optionally be integrated into the microcontroller.

[0013] The electrical energy source may be a battery, preferably a button cell, and / or having a diameter of less than 25 millimeters and / or a height of less than 8 millimeters, for example less than 6 millimeters.

[0014] A first computer program for such a portable identifier is also provided. The computer program comprises instructions which, when the program is executed by a processor of the portable identifier, cause the latter to implement one or more of the steps (e.g. all of the steps) of such a method.

[0015] Also provided is a first computer-readable storage medium having such a first computer program recorded thereon.

[0016] A portable identifier is also provided. The portable identifier comprises such a first storage medium. The portable identifier is configured to perform one or more of the steps (e.g., all of the steps) of such a method.

[0017] A second computer program is also provided for such a vehicle system. The computer program comprises instructions which, when executed by a processor of the vehicle system, cause the vehicle system to implement one or more of the steps (e.g., all of the steps) of such a method.

[0018] Also provided is a second computer-readable storage medium on which such a second computer program is recorded.

[0019] Also provided is a vehicle system having recorded a portable identifier. The vehicle system comprises such a second storage medium. The vehicle system is configured to perform one or more of the steps (e.g. all of the steps) of such a method.

[0020] Also provided is a vehicle system having recorded a portable identifier. The vehicle system comprises such a second storage medium. The vehicle system is configured to perform one or more of the steps (e.g. all of the steps) of such a method.

[0021] A third program is also offered, which includes the first program and the second program. Brief description of the figures

[0022] Non-limiting examples will be described with reference to the following figures:

[0023] Lamontre shows an example flowchart of the process.

[0024] Illustrates an example of communication between a portable identifier and a vehicle system according to the method.

[0025] Illustrates examples of periodic UWB exchanges according to the first, second, third, fourth and fifth periods.

[0026] Illustrates an example of the architecture of the portable identifier. Detailed description

[0027] Referring to the flowchart of the, a method of communication between a portable identifier and a vehicle system having registered the portable identifier is provided. The identifier comprises an electrical power source. The system and the identifier are configured to communicate using a UWB communication protocol in a first perimeter around the vehicle and to communicate using a BLE communication protocol in a second perimeter around the vehicle. The second perimeter includes the first perimeter. The method comprises, while a user carrying the identifier approaches the vehicle, the following five steps. The first step is a first detection S10. The first detection S10 is a detection that the identifier is located in the second perimeter. The second step is performed after the first detection S10.The second step is a realization S20 of tests to trigger a communication using the UWB communication protocol. The tests carried out are periodic according to a first period. The third step is a success of one of the tests carried out resulting in a triggering S30 of the communication. The triggered communication comprises periodic UWB exchanges according to a second period. The second period is shorter than the first period. The fourth step is a second detection S40. The second detection S40 is a detection that the identifier is located at a distance less than or equal to a predetermined close distance. The fifth step is carried out after the second detection S40. The fifth step is a modification S50 of the communication so that the UWB exchanges are periodic according to a third period. The third period is shorter than the second period.

[0028] The method provides enhanced communication between the portable identifier and the vehicle system.

[0029] Indeed, the method makes it possible to adapt the frequency of UWB exchanges between the portable identifier and the vehicle system according to the change in the distance between the portable identifier and the vehicle system. In particular, the method makes it possible to increase this frequency as the user approaches the vehicle. This increase in frequency makes it possible to reduce the consumption of the portable identifier when the user is far from the vehicle. Indeed, reducing the frequency results in fewer UWB exchanges between the identifier and the system, which reduces the consumption of the identifier's energy source. The method therefore improves the lifetime of the portable identifier's electrical energy source.

[0030] On the other hand, the method allows a higher UWB exchange frequency when the user approaches the vehicle, which allows high precision for the vehicle functionalities used when the user is close to the vehicle (such as the location of the identifier). The method therefore particularly effectively improves the lifetime of the electrical energy source of the portable identifier, i.e. without degradation of the functionalities using UWB communication and which are used near the vehicle.

[0031] The vehicle system and the portable identifier are configured to communicate using the UWB (Ultra Wide Band) communication protocol and the BLE (Bluetooth Low Energy) communication protocol. For each protocol, communication means exchanges, for example periodic, of signals between the portable identifier and the vehicle system according to the communication protocol.

[0032] In particular, the UWB communication protocol is used by the system and the portable identifier when the portable identifier is located within the first perimeter around the vehicle, i.e. the exchanges using this UWB protocol (the UWB exchanges) can be carried out within this first perimeter. This first perimeter can comprise all the positions which are located at a distance from the vehicle system less than or equal to a first predetermined distance (for example 7 meters). On a 2D plane materializing the ground, this first perimeter can be represented by a circle centered on the vehicle and having a radius equal to the first predetermined distance.

[0033] The BLE communication protocol is used by the system and the portable identifier when the portable identifier is located in the second perimeter around the vehicle, that is to say that the exchanges using this BLE protocol (the BLE exchanges) can be carried out in this second perimeter. This second perimeter can comprise all the positions which are at a distance from the vehicle system less than or equal to a second predetermined distance (for example 40 meters). On the 2D plane materializing the ground, this second perimeter can be, like the first perimeter, represented by a circle centered on the vehicle, and can have a radius equal to the second predetermined distance.

[0034] The steps of the method may all be performed by the portable identifier or by the vehicle system. Alternatively, one or more steps may be performed by the portable identifier and one or more other steps by the vehicle system. In examples, some steps may also be performed by both devices (portable identifier and vehicle system).

[0035] In examples, the vehicle system may have stored multiple portable identifiers. In this case, when a user carrying one of these portable identifiers approaches the vehicle, the steps of the method may be executed for that identifier. When another of the portable identifiers approaches the vehicle (e.g., being carried by the same or another user), the method may be repeated for that other identifier.

[0036] The method performs steps S10 to S50 while the user carrying the identifier approaches the vehicle. For example, the method may perform steps S10 to S50 while the user is traveling a route to their vehicle, i.e., from a place of stay (e.g., their home, office, hotel, or business such as a store or restaurant) to the vehicle. The method may perform these steps S10 to S50 after a reactivation of the portable identifier. For example, the method may perform these steps S10 to S50 after the portable identifier is retrieved by the user, and the portable identifier has reactivated. This reactivation may be performed automatically by the portable identifier after a movement is detected.While the user is making this journey to the vehicle, the portable identifier may initially be outside the second perimeter, then, at some point during the journey, it may enter the second perimeter. At this point, the method may execute step S10. Alternatively, the identifier may already be within the second perimeter when it lights up (for example when it is placed on a piece of furniture near the vehicle). In this case, step S10 may be executed as soon as it is lit.

[0037] After executing step S10, the method comprises performing the UWB communication triggering tests (step S20). In particular, the method executes step S20 before the identifier has entered the first perimeter. During the user's journey, the portable identifier successively enters the second perimeter and then the first perimeter (the second perimeter being wider and including the first perimeter). The method executes step S20 during the portion of the journey that is located in the second perimeter and before entering the first perimeter.

[0038] When the identifier enters the first perimeter, one of the tests succeeds, which triggers the triggering of the UWB communication (step S30). Once the identifier arrives at a distance less than or equal to the predetermined close distance, the method comprises the second detection S40 that the identifier is at such a distance and then the modification S50 of the period of the UWB exchanges to increase their frequency.

[0039] In examples, the method may be repeated for each trip to the vehicle. For example, the method may be repeated for each home-to-vehicle, work-to-vehicle, hotel-to-vehicle, and / or business-to-vehicle trip made by the user carrying the portable identifier.

[0040] Detection S10 may be performed at the time of entry by the identifier into the second perimeter, i.e. the perimeter of the BLE communication. Detection S10 may comprise a successful completion of one or more first BLE exchanges between the vehicle system and the portable identifier. This or these first BLE exchanges may each comprise a sending of a BLE signal by the system then a reception of this signal by the identifier. Alternatively, for each exchange, the BLE signal may be sent by the identifier then received by the system. The success of these one or more first BLE exchanges between the identifier and the system may mean that the portable identifier is in the second perimeter, i.e. that it is within range of the system. Before the success of these one or more first BLE exchanges, unsuccessful exchange attempts may have been carried out (because the identifier was not yet in the second perimeter).

[0041] After the first detection S10, the method comprises performing the tests S20 for triggering the UWB communication. Performing each test may comprise sending a signal using the UWB communication protocol by the identifier, then listening for the reception of a signal sent in response by the system (or conversely sending a signal by the system and listening for a signal sent in response by the identifier). Each test may fail when no signal sent in response is received (for example beyond a predetermined listening duration), or succeed when a signal sent in response is received during the listening period.

[0042] The tests are periodic according to a first period. This means that a test can be performed every X milliseconds, with X the duration of the first period. At the beginning of each period, the test can include the sending of the signal by the identifier or the system. The listening period can correspond to the time remaining in the X milliseconds after the time for sending this signal has elapsed. In examples, the first period can be less than 800 milliseconds and / or greater than 350 milliseconds, for example about 576 milliseconds. Each test can last 8 milliseconds. The current in the portable identifier can then be greater than 200 uA and / or less than 600 uA, for example about 400 uA.

[0043] After one of the tests has been successfully completed, the method comprises triggering S30 the UWB communication. The UWB communication may be triggered directly after the first successful completion of a test. Triggering S30 may comprise performing one or more UWB exchanges between the portable identifier and the system, in particular to enable a negotiation of communication parameter(s) between the portable identifier and the system. The triggered communication may then comprise UWB exchanges with the negotiated communication parameter(s). The UWB exchanges of the triggered communication are periodic according to a second period. This means that a UWB exchange may be performed every Y milliseconds, with Y the duration of the second period. The duration of the second period is less than the duration of the first period. For example, the first period may be a multiple of the second period. The first period may be equal to twice the second period.In examples, the second period may be less than 350 milliseconds and / or greater than 150 milliseconds, for example about 288 milliseconds. Each UWB exchange may last 20 milliseconds. The current in the portable identifier may then be greater than 1000 uA and / or less than 2000 uA, for example about 1200 uA.

[0044] The second detection S40 is performed after the triggering S30 of the UWB communication. The second detection S40 may comprise monitoring the distance between the portable identifier and the system. The monitoring may comprise measurements, at regular intervals, of the distance between the portable identifier and the system, and, at each measurement, a comparison of the measured distance with the predetermined close distance (the second detection being performed when the measured distance becomes less than or equal to the predetermined close distance). The predetermined close distance may be less than the radius of the first perimeter (which is for example 7 meters). For example, the predetermined close distance may be less than 5 meters and / or greater than 1 meter (for example approximately equal to 3 meters).

[0045] The distance measurements may be made in any manner. For example, the measurements may be made from UWB exchanges of the triggered UWB communication. Each UWB exchange includes a measurement of the distance. In this case, the measurements may be periodic according to the same second period. Each distance measurement may be made from a UWB exchange between the handheld identifier and the system, and may include a calculation of a time of flight for a UWB signal to travel a round-trip distance between the identifier and the system. Such a measurement from a UWB exchange may include a distance and a position of the identifier around the vehicle.

[0046] The modification S50 of the frequency of the UWB exchanges is carried out after the second detection S40. The modification S50 may comprise an increase in the frequency of the UWB exchanges, i.e. an increase in the frequency of sending and receiving the signals forming these UWB exchanges. For example, the UWB exchanges may be programmed, and the modification S50 may comprise a modification of this programming to multiply bynthe number of UWB exchanges initially planned, withna positive integer. For example, the modification S50 may consist of carrying out two or three times more UWB exchanges.

[0047] After modification S50, the communication comprises periodic UWB exchanges with a third period shorter than the second period (some UWB exchanges being deprogrammed). For example, the second period may be a multiple of the third period. The second period may be three times the third period. In examples, the third period may be less than 150 milliseconds and / or greater than 50 milliseconds, for example about 96 milliseconds. Each UWB exchange may last 20 milliseconds. The current in the portable identifier may then be greater than 3000 uA and / or less than 4000 uA, for example about 3600 uA.

[0048] Once the communication S50 is modified, the method may include performing one or more functions based on UWB exchanges of the communication modified. These one or more functions may include unlocking and / or turning on the vehicle remotely, for example, as soon as the user is closer than a safety distance (less than the predetermined close distance). For example, the method may include unlocking and / or turning on the vehicle when the user is 4 meters from the vehicle. In this case, the predetermined close distance is greater than 4 meters. In examples, when the user approaches the vehicle, the method may include performing a welcome function when the user is 3 meters from the vehicle.Alternatively or additionally, the method may comprise executing a function for automatically opening the vehicle doors when the user is within an unlocking distance of the vehicle (for example, a distance equal to 1.2 meters). When the user leaves his vehicle, the method may comprise executing a function for locking the vehicle when the user is within a locking distance of the vehicle. This locking distance may be imposed by regulation, and may be, for example, less than or equal to 2 meters.

[0049] The modified UWB communication may continue, for example, until the user enters the vehicle. After this, the method may comprise detecting that the identifier is in the vehicle (third detection S60). This third detection S60 may be carried out in the same manner as the first and second detections, i.e., from distance measurements and a determination, from these measurements, of the entry of the identifier into the vehicle. After the third detection S60, the method may comprise modifying the communication so that the UWB exchanges are periodic according to a fourth period. The method may carry out this modification in the same manner as modification S50, i.e., by modifying the scheduling of the UWB exchanges, but by reducing the frequency of the UWB exchanges.

[0050] After this second modification, the communication comprises UWB exchanges periods according to the fourth period which is greater than the third period (certain UWB exchanges being for example deprogrammed). For example, the fourth period can be a multiple of the third period. The fourth period can be equal to twice the third period. The fourth period can also be shorter than the second period (certain UWB exchanges remaining for example programmed compared to the programming at the triggering of the communication in step S30). Such a duration for the fourth period is optimal. Indeed, it makes it possible to both reduce consumption, while also ensuring a short reaction time, which is particularly useful, for example for carrying out a function when the user presses a button to turn on the vehicle (a new authentication using a UWB exchange being carried out at this time).

[0051] In examples, the fourth period may be less than 150 milliseconds and / or greater than 50 milliseconds, for example about 96 milliseconds. Each UWB exchange may last 20 milliseconds. The current in the portable identifier may then be greater than 1000 uA and / or less than 2500 uA, for example about 1800 uA.

[0052] In examples, the UWB system and the identifier may be configured to communicate using the UWB communication protocol at the period that is the smallest, i.e., for example, the third period (e.g., 96 milliseconds). In this case, the method may perform the UWB communications at the different frequencies by canceling some UWB exchanges with respect to such UWB communication at the smallest period. For example, the method may perform the communication triggered in step S30 by canceling two out of three UWB exchanges, i.e., by skipping two UWB exchanges after each UWB exchange. The method may also perform the communication modified in step S50 by restoring all UWB exchanges. Similarly, the method may perform the UWB communication according to the fifth period by canceling forty-two UWB exchanges after each UWB exchange, or the UWB communication according to the fourth period by canceling one out of two UWB exchanges.The decision to skip UWB exchanges based on distance can be made by the vehicle system or by the handheld identifier. When the system decides, it can communicate the new period directly to the handheld identifier using BLE communication. Alternatively, the system can be configured to communicate the identifier's distance from the vehicle.

[0053] Examples will now be described with reference to Figures 2 to 4.

[0054] Illustrates an example of communication between a portable identifier and a vehicle system according to the method. The figure shows the vehicle system 100 having registered the portable identifier 200 carried by the user. The system 100 and the identifier 200 are configured to communicate using a UWB communication protocol in a first perimeter 310 around the vehicle 100 and to communicate using a BLE communication protocol in a second perimeter 320 around the vehicle. The figure shows the boundary 321 of the BLE connection and the boundary 311 of the UWB connection. The second perimeter 320 includes the first perimeter 310. The perimeters 310, 320 are only schematically illustrated in the figure, and this illustration therefore does not represent the actual shape and scale of these perimeters.

[0055] It also shows the activities of the BLE component 400 and the UWB component 410 during the execution of the method. It also shows the activities of the motion sensor 420 and the microcontroller 430.

[0056] The method comprises, while a user carrying the identifier approaches the vehicle along the trajectory passing through the points 200, 201 then 202, the following five steps. The first step is a first detection S10. The first detection S10 is a detection that the identifier 200 is located in the second perimeter 320. The second step is carried out after the first detection S10. The second step is a carrying out S20 of tests to trigger a communication using the UWB communication protocol. The tests carried out are periodic according to a first period. The third step is a success of one of the tests carried out resulting in a triggering S30 of the communication 412. The triggered communication 412 comprises periodic UWB exchanges according to a second period. The second period is shorter than the first period. The fourth step is a second detection S40.The second detection S40 is a detection that the identifier 200 is located at a distance less than or equal to a predetermined close distance (3 meters in this example). The fifth step is performed after the second detection S40. The fifth step is a modification S50 of the communication so that the UWB exchanges are periodic according to a third period. The third period is shorter than the second period.

[0057] Also illustrated are steps S60 and S70 of the method, which are executed after the user enters the vehicle. At this time, the method comprises the third detection S60 that the identifier is in the vehicle, then, modifying the communication so that the UWB exchanges are periodic according to a fourth period 414. The third detection S60 and the modification of the communication so that the UWB exchanges are periodic according to a fourth period 414 are carried out as described previously.

[0058] In examples, after the engine of the vehicle 100 has been switched on, the method comprises suspending S70 the communication. For example, the method may comprise detecting the engine has been switched on (e.g., detecting that the user presses a button controlling the ignition), then, immediately thereafter, suspending S70 the communication. The suspension S70 may comprise canceling the scheduling of UWB exchanges between the identifier and the system. The suspension S70 may also comprise putting the UWB component of the identifier into sleep mode. In examples, the suspension S70 may also comprise saving the negotiated session parameters for the suspended UWB communication.Thanks to this registration, the UWB communication can be re-engaged (in particular as described below when the speed becomes slow or when the engine of the vehicle 100 is switched off) without renegotiation of these session parameters, i.e. by using the session parameters which were registered during the suspension S70 and which will have already been negotiated during the triggering S30. This improves the efficiency of the method. The suspension S70 makes it possible to reduce consumption even further.

[0059] In examples, after the suspension S70, the method may include a re-engagement S71 of the communication when the vehicle is traveling at a speed less than or equal to a predetermined speed limit. For example, the method may include monitoring the speed of the vehicle and verifying that the monitored speed does not become less than or equal to the predetermined speed limit (e.g., for a duration greater than a predetermined duration, e.g., a few minutes). The predetermined speed limit may be less than or equal to 10 kilometers per hour and / or greater than or equal to 1 kilometer per hour, e.g., about 3 kilometers per hour. The method may re-engage the communication with the same session parameters as before the suspension S70.

[0060] The method may perform step S71 after the user has completed the journey he or she intended to make with the vehicle (e.g., a home-work, home-hotel, home-shopping or vice versa), i.e., once he or she has almost arrived at the destination, and then reduces the speed of the vehicle. For example, the method may perform step S71 before the user turns off the vehicle's engine and leaves the vehicle.

[0061] In other examples (not shown in the), after the ignition of the engine of the vehicle 100, instead of suspending the communication, the method may comprise a modification of the communication so that the UWB exchanges are periodic according to a fifth period. The fifth period may for example be greater than the fourth period, and optionally greater than the second period. For example, the fifth period may be greater than 1 second and / or less than 10 seconds, for example approximately 4032 milliseconds. Such a modification makes it possible to reduce the consumption of the portable identifier, while maintaining the possibility of regularly checking the position of the identifier.The method can carry out this modification of the communication in the same way as modification of the communication so that the UWB exchanges are periodic according to a fourth period (414), or as modification S50, that is to say by modifying the programming of the UWB exchanges (for example by only carrying out one UWB exchange every Z milliseconds, with a duration equal to the fifth period). Each UWB exchange can last 20 milliseconds. The current in the portable identifier can then be greater than 50 uA and / or less than 100 uA, for example approximately 75 uA.

[0062] Also illustrated are steps S80 and S90 of the method, which are executed after the user has completed the journey he or she intended to make with the vehicle, i.e., once he or she has arrived at the destination, and he or she leaves the vehicle. The method may execute these steps S80 and S90 while the user is traveling an exit route from the vehicle, i.e., from the vehicle to a place of stay (e.g., his or her home, office, hotel, or business such as a store or restaurant) to the vehicle. This place of stay may be the same as during the outward journey, or it may be a different place of stay.

[0063] During this exit path, the method may comprise the fourth detection S80. The fourth detection S80 is a detection that the identifier is located at a distance greater than or equal to the predetermined close distance 210. The method may carry out the fourth detection in the same manner as the first, second and third detections, i.e. by distance measurements and a comparison of the measured distances with the predetermined close distance 210. After this fourth detection S80, the method comprises the suspension S90 of the re-initiated communication.

[0064] In examples, the method may perform the suspension S90 just after the fourth detection S80. In other examples, the method may only perform the suspension S90 later. For example, the method may include, just after the fourth detection, and before the suspension S90, a modification of the UWB communication, for example so that the UWB exchanges are periodic according to the second period 416. In this case, the method may perform the suspension S90 only when the user leaves the first perimeter 310. For example, the suspension S90 may result from a failure of a UWB exchange between the system and the portable identifier (the latter then no longer being within the first perimeter 310 around the vehicle).

[0065] In examples, after the suspension S90, the method may comprise performing tests to trigger a UWB communication 417. The performance of these tests may be identical to that of step S20. The method may stop performing the tests when the identifier leaves the second perimeter 320, for example after a suspension of BLE communication.

[0066] Such a method saves energy representing more than four months of use of the portable identifier. Indeed, the time to go from the border of the second perimeter to that of the first perimeter can represent on average 20 seconds, the time to go from the border of the first perimeter to 3 meters from the vehicle 4.7 seconds, the time to go from 3 meters to the vehicle 2 seconds and the time to turn on and leave with the vehicle 10 seconds. The method therefore makes it possible to reduce the frequency of UWB exchanges over the first 24.7 seconds (with for example an exchange every 192 milliseconds or less) and to maintain a high frequency of UWB exchanges (with for example an exchange every 96 milliseconds) only over the last 2 seconds.

[0067] illustrates examples of periodic UWB exchanges according to the first, second, third, fourth, and fifth periods. In particular, shows an example of periodic UWB exchanges according to the first period 501. Each UWB exchange may be approximately 20 milliseconds. The first period 501 is 576 milliseconds. also shows an example of periodic UWB exchanges according to the second period 502. The second period 502 is 288 milliseconds. The first period 501 is twice the second period 502. also shows an example of periodic UWB exchanges according to the third period 503. The third period 503 is 96 milliseconds. The second period 502 is three times the third period 503. also shows an example of periodic UWB exchanges according to the fourth period 504, which is 192 milliseconds. The fourth period 504 is equal to twice the third period 503.Lamontre also shows an example of S70 suspension of communication 505 (not including UWB exchange). Lamontre also shows an example of periodic UWB exchanges according to the fifth period 506, which is 4032 milliseconds. The fifth period 506 is equal to seven times the first period 501.

[0068] Illustrates an example of architecture 800 of the portable identifier. The architecture 800 comprises a UWB component 810, a BLE component 820, a microcontroller 840 integrating the BLE component 820 and an internal communication 830 between the UWB component 810 and the BLE component 820 (via the microcontroller 840). The architecture 800 comprises a UWB antenna 811 connected to the UWB component 810. The architecture 800 comprises a BLE antenna 821 connected to the BLE component 820 (via the microcontroller 840). The internal communication 830 makes it possible to avoid the UWB component having to integrate a component for measuring time (for example a resonator). The architecture 800 comprises a motion sensor 860 connected to the microcontroller 840. The architecture 800 comprises a battery 850 powering the UWB component 810 and the microcontroller 840. After the prediction S40, the method comprises the triggering S30 of the UWB communication.The trigger S30 comprises sending a wake-up signal by the microcontroller 840 to the UWB component 810 using the internal communication 830. After receiving the wake-up signal, the UWB component 810 can start by drawing power from the electrical power source 850 of the device. The method makes it possible to reduce the activity of the UWB component 810 when the user is far from the vehicle, which reduces the risk of unnecessarily consuming the electrical power source 850.

Claims

A method of communicating between a portable identifier (200) and a vehicle system (100) having registered the portable identifier (200), the identifier (200) comprising an electrical energy source, the system and the identifier (200) being configured to communicate using a UWB communication protocol in a first perimeter (310) around the vehicle and to communicate using a BLE communication protocol in a second perimeter (320) around the vehicle, the second perimeter (320) including the first perimeter (310), the method comprising, while a user carrying the identifier (200) approaches the vehicle (100): a first detection (S10), the first detection (S10) being a detection that the identifier (200) is located in the second perimeter (320);after the first detection (S10), carrying out tests (S20) to trigger a communication using the UWB communication protocol, the tests carried out being periodic according to a first period; a success of one of the tests carried out resulting in a triggering (S30) of the communication (412), the triggered communication (412) comprising periodic UWB exchanges according to a second period, the second period being shorter than the first period; a second detection (S40), the second detection (S40) being a detection that the identifier (200) is located at a distance less than or equal to a predetermined close distance (210); andafter the second detection (S40), a modification (S50) of the communication so that the UWB exchanges are periodic according to a third period, the third period being shorter than the second period.; The method of claim 1, wherein the method further comprises:a third detection (S60), the third detection (S60) being a detection that the identifier (200) is located in the vehicle (100); andafter the third detection (S60), modifying the communication so that the UWB exchanges are periodic according to a fourth period (414), the fourth period being larger than the third period and / or shorter than the second period. Method according to claim 1 or 2, wherein the method further comprises:after ignition of the engine of the vehicle (100):a suspension (S70) of the communication, ora modification of the communication so that the UWB exchanges are periodic according to a fifth period, the fifth period being greater than the fourth period, and optionally greater than the second period; andoptionally, after the suspension (S70) of the communication, a reactivation (S71) of the communication when the vehicle is traveling at a speed less than or equal to a predetermined speed limit. The method of claim 3, wherein the method further comprises:after stopping the engine of the vehicle (100):when the communication is suspended, re-engaging the communication using the UWB communication protocol, the re-engaging communication comprising periodic UWB exchanges according to the third period (415), orwhen the communication comprises periodic UWB exchanges according to the fourth or fifth period, modifying the communication so that the UWB exchanges are periodic according to the third period (415);a fourth detection (S80), the fourth detection (S80) being a detection that the identifier is located at a distance greater than or equal to the predetermined close distance (210); andafter the fourth detection (S80), suspending (S90) the re-engaging communication. Method according to one of the preceding claims, wherein:the first period is a multiple of the second period;the second period is a multiple of the third period; and / orthe fourth period is a multiple of the third period. Method according to one of the preceding claims, in which the portable identifier comprises a microcontroller, a BLE component and a UWB component, the triggering of the communication comprising sending a wake-up signal by the microcontroller to the UWB component, the BLE component being optionally integrated into the microcontroller. Method according to one of the preceding claims, in which the source of electrical energy is a battery, preferably a button cell, and / or having a diameter of less than 25 millimeters and / or a height of less than 8 millimeters, for example less than 6 millimeters. A computer program for a portable identifier and / or vehicle system comprising instructions which, when the program is executed by a processor, cause the latter to implement the method according to any one of claims 1 to 7. Computer-readable storage medium on which the computer program according to claim 8 is recorded. A portable identifier and / or system for a vehicle comprising the storage medium according to claim 9, the portable identifier and / or system being configured to perform the method according to any one of claims 1 to 7.

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