UWB communication between vehicle system and wearable identifier

Abstract

A method for communication between a wearable identifier and a vehicle system that has registered the wearable identifier is proposed. The system and the identifier are configured to communicate using a UWB communication protocol within a first perimeter around the vehicle and to communicate using a BLE communication protocol within a second perimeter around the vehicle. The method includes, while a user wearing the identifier approaches the vehicle, a detection S10 that the identifier is located within the second perimeter, a test S20 to initiate a UWB communication, a successful test S30 triggering the communication, a detection S40 that the identifier is located at a distance less than or equal to a predetermined near distance, and a modification S50 of the communication to reduce the frequency of UWB exchanges.The process provides improved communication between the identifier and the system. [Fig. 1].

Description

Title of the invention: UWB communication between vehicle system and portable identifier technical field

[0001] This 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] Vehicles equipped with systems that have stored one or more portable identifiers now exist. These portable identifiers can be portable devices such as key fobs or smartphones. Each identifier includes a source of electrical power (for example, a battery) enabling it to be portable. Such systems allow the vehicle to perform functions, such as unlocking the doors and / or starting the vehicle, depending on the location of one or more portable identifiers.

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

[0004] In particular, UWB communication generally includes periodic UWB exchanges. The participation of the portable identifier in these periodic UWB exchanges consumes a significant portion of the lifetime of its energy source.

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

[0006] A method for communication between a portable identifier and a vehicle system that has registered the portable identifier is proposed for this purpose. The identifier includes a source of electrical power. The system and the identifier are configured to communicate using a UWB communication protocol in the first The procedure involves establishing a perimeter around the vehicle and communicating using a BLE communication protocol within a second perimeter around the vehicle. This second perimeter includes the first perimeter. The procedure includes the following five steps while a user carrying the identifier approaches the vehicle. The first step is an initial detection. This initial detection is when the identifier is located within the second perimeter. The second step is performed after the initial detection. The second step involves conducting communication trigger tests using the UWB communication protocol. These tests are performed periodically according to a first period. The third step is when one of the tests is successful, resulting in a communication trigger. The triggered communication consists of periodic UWB exchanges according to a second period. This second period is shorter than the first period.The fourth step is a second detection. The second detection determines that the identifier is located at a distance less than or equal to a predetermined near distance. The fifth step is performed after the second detection. The fifth step modifies the communication so that UWB exchanges are periodic according to a third period. This third period is shorter than the second period.

[0007] The method may further include a third detection step. This third detection step may be to detect that the identifier is located in the vehicle. The method may further include, after the third detection step, a modification of the communication so that the UWB exchanges are periodic according to a fourth period. This fourth period may be longer than the third period and / or shorter than the second period.

[0008] The method may further include, after the vehicle engine has been started, suspending communication, or modifying the communication so that UWB exchanges are periodic according to a fifth period. The fifth period may be longer than the fourth period. Optionally, the fifth period may also be longer than the second period.

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

[0010] The method may further include, after the vehicle engine has stopped, when communication is suspended, re-establishing communication using the UWB communication protocol. The re-established communication may include periodic UWB exchanges according to the third period. The method may further include, after the vehicle engine has stopped, when communication includes periodic UWB exchanges according to the fourth or In the fifth period, the communication is modified so that UWB exchanges are periodic according to the third period. The method may further include a fourth detection. This fourth detection may be when the identifier is located at a distance greater than or equal to the predetermined near distance. The method may further include, after the fourth detection, a suspension and subsequent resumption of the communication.

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

[0012] The identifier may include a microcontroller, a BLE component, and a UWB component. Communication initiation 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 can be a battery, preferably a button cell, and / or have 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 proposed. The computer program includes 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 (for example, all the steps) of such a process.

[0015] A first computer-readable storage medium is also proposed on which such a first computer program is recorded.

[0016] A portable identifier is also proposed. The portable identifier includes such a first storage medium. The portable identifier is configured to execute one or more of the steps (for example, all the steps) of such a process.

[0017] A second computer program for such a vehicle system is also proposed. The computer program includes instructions which, when the program is executed by a processor of the vehicle system, cause the latter to implement one or more of the steps (for example, all the steps) of such a process.

[0018] A second computer-readable storage medium is also proposed on which such a second computer program is recorded.

[0019] A vehicle system with a stored portable identifier is also proposed. The vehicle system includes such a second storage medium. The vehicle system is configured to execute one or more steps (for example, all steps) of such a method.

[0020] A vehicle system with a stored portable identifier is also proposed. The vehicle system includes such a second storage medium. The vehicle system is configured to execute one or more steps (for example, all steps) of such a method.

[0021] A third program is also proposed, comprising 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] [Fig.1] shows an example flowchart of the process.

[0024] Figure [Fig.2] illustrates an example of communication between a portable identifier and a vehicle system according to the method.

[0025] Fig. 3 illustrates examples of periodic UWB exchanges according to the first, second, third, fourth and fifth periods.

[0026] Figure 4 illustrates an example of portable identifier architecture. Detailed description

[0027] With reference to the flowchart in [Fig. 1], a method for communication between a wearable identifier and a vehicle system that has registered the wearable identifier is proposed. The identifier includes a power source. The system and the identifier are configured to communicate using a UWB communication protocol within a first perimeter around the vehicle and to communicate using a BLE communication protocol within a second perimeter around the vehicle. The second perimeter includes the first perimeter. The method comprises the following five steps while a user wearing the identifier approaches the vehicle. The first step is an initial detection S10. The initial detection S10 is a detection that the identifier is located within the second perimeter. The second step is performed after the initial detection S10.The second step is an S20 execution of communication trigger tests using the UWB communication protocol. The tests are performed periodically according to a first period. The third step is the successful completion of one of the tests, resulting in an S30 trigger of the communication. The triggered communication consists of periodic UWB exchanges according to a second period. The second period is shorter than the first period. The fourth step is a second S40 detection. The second S40 detection is the detection that the identifier is located at a distance less than or equal to a predetermined near distance. The fifth step is performed after the second S40 detection. The fifth step is an S50 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.

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

[0029] Indeed, the method allows the frequency of UWB exchanges between the wearable device and the vehicle system to be adapted according to changes in the distance between the wearable device and the vehicle system. In particular, the method allows this frequency to increase as the user approaches the vehicle. This increase in frequency reduces the wearable device's power consumption when the user is far from the vehicle. In fact, reducing the frequency results in fewer UWB exchanges between the device and the system, which reduces the power consumption of the device's power source. The method therefore improves the lifespan of the wearable device's power source.

[0030] Furthermore, the method allows for a higher UWB exchange frequency when the user approaches the vehicle, thus enabling high accuracy for vehicle functionalities used when the user is near the vehicle (such as identifier location). The method therefore particularly effectively improves the lifespan of the portable identifier's power source, i.e., without degrading the functionalities using UWB communication and which are used in close proximity to the vehicle.

[0031] The vehicle system and the wearable 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 refers to the exchange, for example periodic, of signals between the wearable identifier and the vehicle system according to the communication protocol.

[0032] In particular, the UWB communication protocol is used by the system and the wearable device when the wearable device is within the first perimeter around the vehicle; that is, exchanges using this UWB protocol (UWB exchanges) can be carried out within this first perimeter. This first perimeter can include all positions 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 representing 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 wearable identifier when the wearable identifier is within the second perimeter around the vehicle, This means that exchanges using this BLE protocol (BLE exchanges) can be carried out within this second perimeter. This second perimeter can include all positions located at a distance from the vehicle system less than or equal to a second predetermined distance (for example, 40 meters). On the 2D plane representing the ground, this second perimeter, like the first perimeter, can be represented by a circle centered on the vehicle, and can have a radius equal to the second predetermined distance.

[0034] All the steps of the process can be performed by the handheld identifier or by the vehicle system. Alternatively, one or more steps can be performed by the handheld identifier and one or more other steps by the vehicle system. In some examples, certain steps can also be performed by both devices (handheld identifier and vehicle system).

[0035] In some examples, the vehicle system may have stored several wearable identifiers. In this case, when a user wearing one of these wearable identifiers approaches the vehicle, the steps of the process can be executed for that identifier. When another of the wearable identifiers approaches the vehicle (for example, being worn by the same or another user), the process can be repeated for that other identifier.

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

[0037] After the execution of step S10, the method includes performing the UWB communication trigger tests (step S20). In particular, the method performs step S20 before the identifier enters 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 more large and including the first perimeter). The process performs step S20 during the part of the path that lies within the second perimeter and before entering the first perimeter.

[0038] When the identifier enters the first perimeter, one of the trials is successful, triggering the UWB communication (step S30). Once the identifier reaches a distance less than or equal to the predetermined near distance, the method includes a second detection S40 that the identifier is at such a distance, followed by a modification S50 of the UWB exchange period to increase its frequency.

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

[0040] S10 detection can occur when the identifier enters the second perimeter, i.e., the BLE communication perimeter. S10 detection can include the success of one or more initial BLE exchanges between the vehicle system and the wearable identifier. Each of these initial BLE exchanges can consist of the system sending a BLE signal followed by the identifier receiving that signal. Alternatively, for each exchange, the BLE signal can be sent by the identifier and then received by the system. The success of these initial BLE exchanges between the identifier and the system can mean that the wearable identifier is in the second perimeter, i.e., it is within range of the system. Before the success of these initial BLE exchanges, unsuccessful exchange attempts may have been made (because the identifier was not yet in the second perimeter).

[0041] After the initial detection S10, the method comprises performing the UWB communication triggering tests S20. Each test may involve the identifier sending a signal using the UWB communication protocol, followed by listening for a response signal sent by the system (or conversely, the system sending a signal and the identifier listening for a response signal). Each test may fail when no response signal is received (for example, after a predetermined listening period), or succeed when a response signal is received during the listening period.

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

[0043] After the success of one of the tests, the method includes triggering UWB communication S30. UWB communication can be triggered directly after the first successful test. Triggering S30 may include one or more UWB exchanges between the wearable identifier and the system, notably to allow negotiation of communication parameter(s) between the wearable identifier and the system. The triggered communication may then include 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 can be performed every Y milliseconds, where Y is the duration of the second period. The duration of the second period is shorter than the duration of the first period. For example, the first period may be a multiple of the second period.The first period can be equal to twice the second period. In examples, the second period can be less than 350 milliseconds and / or more than 150 milliseconds, for example, approximately 288 milliseconds. Each UWB exchange can last 20 milliseconds. The current in the wearable identifier can then be greater than 1000 µA and / or less than 2000 µA, for example, approximately 1200 µA.

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

[0045] Distance measurements can be performed in any way. For example, measurements can be taken from UWB exchanges of the triggered UWB communication. Each UWB exchange includes a distance measurement. In this case, the measurements can be periodic according to the same second period. Each distance measurement can be taken from a UWB exchange between the wearable identifier and the system, and can include a time-of-flight calculation for that a UWB signal travels a round-trip distance between the identifier and the system. Such a measurement from a UWB exchange can include a distance and a position of the identifier around the vehicle.

[0046] The S50 modification of the UWB exchange frequency is performed after the second S40 detection. The S50 modification may include an increase in the UWB exchange frequency, that is, an increase in the sending and receiving frequency of the signals constituting these UWB exchanges. For example, the UWB exchanges may be programmed, and the S50 modification may include a change to this programming to multiply by n the number of UWB exchanges initially planned, where n is a positive integer. For example, the S50 modification may consist of executing two or three times as many 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 equal to three times the third period. In examples, the third period may be less than 150 milliseconds and / or more than 50 milliseconds, for example, by about 96 milliseconds. Each UWB exchange may last 20 milliseconds. The current in the portable identifier may then be greater than 3000 µA and / or less than 4000 µA, for example, by about 3600 µA.

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

[0049] The modified UWB communication can continue, for example, until the user enters the vehicle. After that, the method can include detecting that the identifier is in the vehicle (third detection S60). This third detection S60 can be performed in the same way as the first and second detections, that is, based on distance measurements and determining, from these measurements, when the identifier has entered the vehicle. After the third detection S60, the method can include modifying the communication so that the UWB exchanges are periodic according to a fourth period. The method can perform this modification in the same way as modification S50, that is, by modifying the programming of the UWB exchanges, but by reducing the frequency of the UWB exchanges.

[0050] After this second modification, the communication comprises UWB exchanges with periods where the fourth period is longer than the third period (some UWB exchanges being, for example, deprogrammed). For instance, the fourth period can be a multiple of the third period. The fourth period can be twice the length of the third period. The fourth period can also be shorter than the second period (some UWB exchanges remaining programmed, for example, with respect to the programming at the start of communication in step S30). Such a duration for the fourth period is optimal. Indeed, it allows both a reduction in power consumption and a short response time, which is particularly useful, for example, for the execution of a function when the user presses a button to start the vehicle (a new authentication using a UWB exchange is performed at that moment).

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

[0052] In examples, the UWB system and the identifier can be configured to communicate using the UWB communication protocol at the shortest period, i.e., for example, the third period (96 milliseconds, for example). In this case, the method can carry out UWB communications at different frequencies by canceling certain UWB exchanges compared to such UWB communication at the shortest period. For example, the method can carry out the communication triggered at step S30 by canceling two out of three UWB exchanges, i.e., by skipping two UWB exchanges after each UWB exchange. The method can also carry out the modified communication at step S50 by re-establishing all UWB exchanges. Similarly, the method can carry out UWB communication according to The fifth period involves skipping forty-two UWB exchanges after each UWB exchange, or alternatively, UWB communication can be performed according to the fourth period by skipping every other UWB exchange. The decision to skip UWB exchanges based on distance can be made by the vehicle's system or by the wearable device. When the system decides, it can directly communicate the new period to the wearable device using BLE communication. Alternatively, the system can be configured to communicate the distance of the wearable device from the vehicle.

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

[0054] Figure 2 illustrates an example of communication between a wearable identifier and a vehicle system according to the method. The figure shows the vehicle system 100 having registered the wearable identifier 200 carried by the user. The system 100 and the identifier 200 are configured to communicate using a UWB communication protocol within a first perimeter 310 around the vehicle 100 and to communicate using a BLE communication protocol within 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 and 320 are shown only schematically in the figure, and this illustration therefore does not represent the actual shape and scale of these perimeters.

[0055] Figure 2 also shows the activities of the BLE component 400 and the UWB component 410 during the execution of the process. Figure 2 also shows the activities of the motion sensor 420 and the microcontroller 430.

[0056] The method comprises, while a user wearing the identifier approaches the vehicle along the trajectory passing through points 200, 201, and then 202, the following five steps. The first step is an initial detection S10. The initial detection S10 is a detection that the identifier 200 is located within the second perimeter 320. The second step is performed after the initial detection S10. The second step is a test S20 of triggering a communication using the UWB communication protocol. The tests performed are periodic according to a first period. The third step is a successful completion of one of the tests, resulting in a trigger 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 S40 detection is a detection that identifier 200 is located at a distance less than or equal to a predetermined near distance (3 meters in this example). The fifth step is performed after the second S40 detection. The fifth step is an S50 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.

[0057] Figure 2 also illustrates steps S60 and S70 of the method, which are executed after the user enters the vehicle. At this point, the method includes the third detection S60 that the identifier is in the vehicle, followed by the modification of 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 vehicle 100 is started, the method includes S70 suspension of communication. For example, the method may include detecting the engine start (e.g., detecting that the user is pressing a button to start the engine), and then, immediately thereafter, S70 suspension of communication. S70 suspension may include canceling the scheduling of UWB exchanges between the identifier and the system. S70 suspension may also include putting the UWB component of the identifier into standby mode. In examples, S70 suspension may also include recording the session parameters negotiated for the suspended UWB communication.Thanks to this recording, UWB communication can be re-established (particularly as described below when the speed slows or when the vehicle's engine stops) without renegotiating these session parameters, i.e., by using the session parameters that were recorded during the S70 suspension and that will have already been negotiated during the S30 triggering. This improves the efficiency of the process. The S70 suspension allows for even further reductions in fuel consumption.

[0059] In examples, after the S70 suspension, the method may include an S71 re-establishment of 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 vehicle's speed and verifying that the monitored speed does not fall below or equal to the predetermined speed limit (for example, for a period longer than a predetermined duration, such as 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, for example, approximately 3 kilometers per hour. The method may re-establish communication with the same session parameters as before the S70 suspension.

[0060] The method can perform step S71 after the user has completed the journey he or she wanted to make with the vehicle (for example a home-work, home-hotel, home-shop or vice versa journey), that is to say once he or she is almost at his or her destination, and he or she then reduces the speed of the vehicle. For example, the process can perform step S71 before the user turns off the vehicle's engine and leaves the vehicle.

[0061] In other examples (not shown in [Fig. 2]), after the engine of vehicle 100 is started, instead of suspending communication, the method may include modifying the communication so that the UWB exchanges are periodic according to a fifth period. The fifth period may, for example, be longer than the fourth period, and optionally longer 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 power consumption of the portable identifier, while still maintaining the ability to regularly check the identifier's position.The method can achieve this communication modification in the same way as modifying the communication so that UWB exchanges are periodic according to a fourth period (414), or as the S50 modification, i.e., by modifying the programming of the UWB exchanges (for example, by performing only one UWB exchange every Z milliseconds, with Z 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 µA and / or less than 100 µA, for example, by about 75 µA.

[0062] Figure 2 also illustrates steps S80 and S90 of the method, which are performed after the user has completed their intended journey with the vehicle, i.e., once they have arrived at their destination and exited the vehicle. The method can perform 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 (for example, their home, office, hotel, or business such as a shop or restaurant) and back to the vehicle. This place of stay may be the same as during the outbound journey, or it may be a different place of stay.

[0063] During this output path, the method may include 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 near distance 210. The method may perform the fourth detection in the same way as the first, second, and third detections, that is, by measuring distances and comparing the measured distances with the predetermined near distance 210. After this fourth detection S80, the method includes the suspension S90 of the re-established communication.

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

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

[0066] Such a method saves energy equivalent to more than four months of use of the wearable identifier. Indeed, the time to travel from the boundary of the second perimeter to that of the first perimeter can average 20 seconds, the time to travel from the boundary of the first perimeter to 3 meters from the vehicle 4.7 seconds, the time to travel from 3 meters to the vehicle 2 seconds, and the time to turn on and depart with the vehicle 10 seconds. The method therefore reduces the frequency of UWB exchanges during the first 24.7 seconds (for example, with an exchange every 192 milliseconds or less) and maintains a high frequency of UWB exchanges (for example, with an exchange every 96 milliseconds) only during the last 2 seconds.

[0067] Figure 3 illustrates examples of periodic UWB exchanges according to the first, second, third, fourth, and fifth periods. In particular, Figure 3 shows an example of periodic UWB exchanges according to the first period 501. Each UWB exchange can be approximately 20 milliseconds. The first period 501 is 576 milliseconds. Figure 3 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 equal to twice the second period 502. Figure 3 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 equal to three times the third period 503. [Fig. 3] 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. [Fig.Figure 3 also shows an example of S70 suspension of 505 communication (not including UWB exchange). Figure 3 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] Figure 4 illustrates an example of the 800 architecture of the portable identifier. The 800 architecture comprises a UWB 810 component, a BLE 820 component, a The 840 microcontroller integrates the 820 BLE component and an 830 internal communication between the 810 UWB component and the 820 BLE component (via the 840 microcontroller). The 800 architecture includes a 811 UWB antenna connected to the 810 UWB component. The 800 architecture includes a 821 BLE antenna connected to the 820 BLE component (via the 840 microcontroller). The 830 internal communication eliminates the need for the UWB component to integrate a time measurement component (e.g., a resonator). The 800 architecture includes a 860 motion sensor connected to the 840 microcontroller. The 800 architecture includes a 850 battery powering the 810 UWB component and the 840 microcontroller. After prediction S40, the process includes triggering the UWB communication S30. The S30 triggering process involves sending a wake-up signal from the 840 microcontroller to the 810 UWB component using the 830 internal communication.After receiving the wake-up signal, the UWB 810 component can start up by drawing power from the device's electrical power source 850. This reduces the activity of the UWB 810 component when the user is away from the vehicle, thus minimizing the risk of unnecessarily consuming the electrical power source 850.

Claims

1. Demands A method of communication between a portable identifier (200) and a vehicle system (100) having registered the portable identifier (200), the identifier (200) comprising a source of electrical power, 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 (S 10), the first detection (S 10) being a detection that the identifier (200) is located in the second perimeter (320); • after the first detection (S 10), a series of tests (S20) to trigger a communication using the UWB communication protocol, the tests carried out being periodic according to a first period; • a successful outcome 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 near distance (210); • after 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; • a third detection (S60), the third detection (S60) being a detection that the identifier (200) is located in the vehicle (100); and

2.

3. • after the third detection (S60), a modification of the communication so that the UWB exchanges are periodic according to a fourth period (414), the fourth period being longer than the third period and shorter than the second period. A method according to claim 1, wherein the method further comprises: • after starting the vehicle's engine (100): • a suspension (S70) of communication, or • a modification of the communication so that UWB exchanges are periodic according to a fifth period, the fifth period being longer than the fourth period, and optionally longer than the second period; and • Optionally, after the suspension (S70) of communication, a reactivation (S71) of communication when the vehicle is traveling at a speed less than or equal to a predetermined speed limit. A method according to claim 2, wherein the method further comprises: • after the vehicle's engine has stopped (100): • when communication is suspended, a re-establishment of communication using the UWB communication protocol, the re-established communication comprising periodic UWB exchanges according to the third period (415), or • where the communication includes 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 (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 near distance (210); and • after the fourth detection (S80), a suspension (S90) of the communication is re-engaged.

4. A method according to any 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 / or • the fourth period is a multiple of the third period.

5. A method according to any one of the preceding claims, wherein the wearable identifier comprises a microcontroller, a BLE component and a UWB component, the triggering of communication comprising sending a wake-up signal by the microcontroller to the UWB component, the BLE component being optionally integrated into the microcontroller.

6. A method according to any one of the preceding claims, wherein the electrical power source 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.

7. A computer program for a portable identifier and / or vehicle system comprising instructions which, when the program is executed by a processor, cause the processor to implement the method according to any one of claims 1 to 6.

8. Computer-readable storage medium on which the computer program according to claim 7 is recorded.

9. Portable identifier and / or vehicle system comprising the storage medium according to claim 8, the portable identifier and / or system being configured to perform the method according to any one of claims 1 to 6.