Triggering UWB communication between vehicle system and wearable identifier

Abstract

A method is proposed for using a vehicle system that has registered a portable identifier. 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 that includes the first perimeter. The method includes, as a user wearing the identifier approaches the vehicle, detecting that the identifier is located within the second perimeter and taking two distance measurements between the user and the vehicle. The method then includes determining the user's speed and predicting the remaining time until the user reaches a predetermined proximity distance from the vehicle. After the predicted remaining time has elapsed, the method includes initiating communication using the UWB communication protocol.The method provides improved use of the portable identifier. [Fig. 1].

Description

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

[0001] This disclosure relates to a method of using a vehicle system having recorded a portable identifier, a computer program for such a system and / or such a portable identifier, a storage medium for such a program, a portable identifier and 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, BLE communication is used to ensure that the wearable identifier is at a safe distance from the vehicle before a UWB communication is initiated. To this end, existing solutions perform BLE exchanges between the system and the wearable identifier while the user approaches the vehicle. However, these BLE exchanges consume the lifetime of the electrical power source.

[0005] There is therefore a need to improve the use of such a system having recorded such a portable identifier. Summary

[0006] For this purpose, a method of using a vehicle system having in A portable identifier is registered. 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, while a user wearing the identifier approaches the vehicle, the following five steps. The first step is a detection that the identifier is located within the second perimeter. The second step is performed after the detection and before the user reaches the first perimeter. The second step is a first and second distance measurement between the user and the vehicle using the BLE communication protocol. The second measurement is performed after the first measurement.The third step is to determine the user's speed based on the first and second distance measurements. The fourth step is to predict the remaining time for the user to reach a predetermined distance from the vehicle, based on the determined speed. The fifth step is to initiate communication using the UWB communication protocol after the predicted remaining time has elapsed.

[0007] The prediction may include a calculation of a remaining distance between the distance measured by the second measurement and the predetermined nearby distance, and, a calculation of the remaining time corresponding to the time for the user to travel the remaining distance given the determined speed.

[0008] The method may include, after the user leaves the vehicle, the following four steps. The first step may be a detection (S60) that the identifier leaves a predetermined security perimeter around the vehicle, the first perimeter including the predetermined security perimeter. The second step may be a suspension (S70) of communication using the UWB communication protocol. The third step may be a monitoring (S80) of RSSI measurements of successive BLE exchanges executed after the deactivation of communication using the UWB communication protocol. The fifth step may be a reactivation (S90) of communication using the UWB communication protocol when the monitoring indicates that the user is returning to the vehicle.

[0009] The monitoring may indicate that the user is returning to the vehicle when one or more of the RSSI measurements of successive BLE exchanges are greater than one or more of the RSSI measurements of previous BLE exchanges.

[0010] The successive BLE exchanges being monitored may include all BLE exchanges between the system and the identifier.

[0011] The identifier may include a microcontroller, a BLE component and a UWB component. Communication triggering may involve the microcontroller sending a wake-up signal to the UWB component. The BLE component may optionally be integrated into the microcontroller.

[0012] 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.

[0013] 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.

[0014] A first computer-readable storage medium is also proposed on which such a first computer program is recorded.

[0015] 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.

[0016] 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.

[0017] A second computer-readable storage medium is also proposed on which such a second computer program is recorded.

[0018] 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.

[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 third program is also proposed, comprising the first program and the second program. Brief description of the figures

[0021] Non-limiting examples will be described with reference to the following figures:

[0022] [Fig.1] and [Fig.2] show flowcharts of examples of the process.

[0023] Figure 3 illustrates an example of the use of the vehicle system according to the process.

[0024] Figure 4 illustrates a comparison of an example of the use of the vehicle system according to the method with the use of the system according to an existing solution.

[0025] Figure 5 illustrates an example of portable identifier architecture. Detailed description

[0026] With reference to the flowchart in [Fig. 1], a method is proposed for using a vehicle system that has registered a portable identifier. 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, S10, is a detection that the identifier is located within the second perimeter. The second step, S20, is performed after the S10 detection and before the user reaches the first perimeter.The second step, S20, involves taking first and second distance measurements between the user and the vehicle using the BLE communication protocol. The second measurement is taken after the first. The third step, S30, determines the user's speed based on the first and second distance measurements. The fourth step, S40, predicts the remaining time for the user to reach a predetermined distance based on the determined speed. The fifth step, S50, initiates communication using the UWB communication protocol after the predicted remaining time has elapsed.

[0027] The method provides improved use of the portable identifier.

[0028] Indeed, the method enables communication using the UWB communication protocol to be triggered only when the wearable identifier is within the range of the UWB communication protocol. This avoids the need for unsuccessful attempts to trigger UWB communication while the user approaches the vehicle. The method therefore improves the lifespan of the wearable identifier's power source.

[0029] In particular, the two distance measurements allow for a precise and reliable assessment of the remaining distance the user must travel to reach the predetermined near distance. They therefore allow for an estimation of the time remaining for the user to be within the first perimeter in which a UWB communication can be initiated. The method uses this estimation, thus avoiding the need to use other means to achieve this (such as the BLE exchanges used in solutions). existing ones). In particular, the process allows these other means to be replaced by just two distance measurements. The process thus saves energy from the portable identifier's power source.

[0030] Furthermore, the method takes into account the fact that the user may move at different speeds to approach the vehicle. For example, the user may run when it is raining or walk slowly while typing a message on their phone. Distance measurements allow these different speeds to be taken into account and the triggering to be adjusted accordingly. In each of these different situations, the method therefore allows the UWB communication to be triggered at the right time.

[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 device when the wearable device is within the second perimeter around the vehicle; that is, 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] Steps S10 to S50 can be executed 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 (portable 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, when worn by the same user or by 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, then, at some point during the journey, it may enter the second perimeter. At this point, the process can execute step S10.

[0037] After the identifier has entered the first perimeter and after step S10 has been executed, the process can execute step S20. In particular, the process 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 larger and including the first perimeter). The process executes step S20 during the portion of the journey that lies within the second perimeter and before entry into the first perimeter.

[0038] After step S20, the method executes steps S30 and S40 to predict the remaining time for the user to reach the predetermined near distance of the vehicle. Step S50 is executed by the method after the predicted remaining time has elapsed, that is, at the moment when the method predicts that the user is at the predetermined near distance of the vehicle.

[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 wearing 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 a first BLE exchange between the vehicle system and the wearable identifier. This first BLE exchange can include the system sending a signal followed by the identifier receiving that signal. Alternatively, the signal can be sent by the identifier and then received by the system. In some examples, S10 detection can include the success of several BLE exchanges between the identifier and the system (the identifier was only detected in the second perimeter after these several BLE exchanges had been successful). The occurrence of this first BLE exchange or exchanges between the identifier and the system can mean that the wearable identifier is in the second perimeter, i.e., that it is within range of the system.Before the success of this first BLE exchange, unsuccessful exchange attempts may have been made (because the identifier was not yet in the second perimeter).

[0041] The S20 realization of the distance measurements can also be performed from one or more BLE exchanges between the system and the identifier (for example, one for each measurement). The first measurement can be performed after the S10 detection. For example, the first measurement can be performed immediately after the S10 detection (i.e., from a BLE exchange performed immediately after the first exchange). Alternatively, the first measurement can be performed after a predetermined time has elapsed since the S10 detection (for example, more than 1 second and / or less than 5 seconds, for example, 3 seconds after the S10 detection that the identifier is within the first perimeter). The second measurement is then performed after the first measurement.For example, the second measurement can be taken after a second predetermined duration has elapsed since the first measurement (e.g., more than 5 seconds and / or less than 20 seconds, e.g., 10 seconds after the first measurement).

[0042] The first and second distance measurements can be performed in any way. For example, each measurement can be performed using channel sounding technology, which is notably compatible with Bluetooth 5 (e.g., nxp HADM). For example, each measurement can include a BLE exchange between the identifier and the system and the calculation of a time-of-flight between the identifier and the system during this BLE exchange. This time-of-flight can be the time taken by the signal exchanged during the BLE exchange to travel to and from the identifier and the system. The time-of-flight can be calculated by the identifier or the system, and can be performed in any way. For example, each measurement can include recordings of the times the exchanged signal is sent and received, and the calculation can be performed by deducing these recordings. The time taken by the signal to travel to and from the system is recorded. Each measurement can then include a deduction of the distance between the identifier and the system from this time of flight. For example, each measurement can involve multiplying a signal velocity by the calculated time of flight. The signal velocity could, for example, be a predetermined and known velocity for that type of signal (e.g., stored in the memory of the identifier or the system).

[0043] The S30 speed determination can be performed by the identifier or by the system. The S30 determination can be based on the two distance measurements taken. The S30 determination can also be based on the time elapsed between the two distance measurements (i.e., for example, on the second predetermined time discussed previously). The S30 speed determination can be made assuming that the user is moving in a straight line towards the vehicle. For example, the S30 determination can include calculating the distance traveled by the user between the two distance measurements (by subtracting the distances measured for the two measurements) and dividing this calculated distance by the time elapsed between the two distance measurements (i.e., by the second predetermined time).

[0044] Similar to the S30 determination, the S40 prediction can be performed by the identifier or by the system. In some examples, the predetermined near distance can be substantially equal to the radius of the first perimeter; that is, this distance can correspond to the maximum range (e.g., permitted by regulations) for establishing a UWB communication (e.g., 7 meters). The method thus ensures that the identifier is within the first perimeter before triggering the UWB communication (step S50). In other examples, the predetermined near distance can be less than this radius of the first perimeter. For example, the predetermined near distance can be less than 5 meters and / or greater than 1 meter (e.g., approximately 3 meters). This further increases the energy savings of the power source, as the UWB communication is triggered even later.Once communication is initiated, the process may include the execution of one or more functions based on UWB exchanges of the initiated communication. These one or more functions may include remotely activating the vehicle, for example, as soon as the user is closer than the predetermined near distance. For example, the process may include activating the vehicle when the user is 4 meters away from the vehicle. In this case, the predetermined near distance is greater than 4 meters.

[0045] The S40 prediction of the remaining time from the determined speed can be made in any way. For example, the S40 prediction may include a calculation of the remaining distance to be traveled by the user to reach the predetermined near distance. For example, the S40 prediction may assume that The user moves in a straight line towards the vehicle and can understand a calculation of the remaining distance by subtracting the predetermined near distance from the distance measured during the second measurement. The S40 prediction can then include a calculation of the remaining time by dividing the remaining distance by the user's speed determined in step S30.

[0046] Similar to the S30 determination and the S40 prediction, the triggering can be performed by the identifier or by the system. The S50 triggering can 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 method can include waiting for the predicted remaining time to elapse before performing these one or more UWB exchanges. The waiting can be performed using an internal clock (for example, a digital clock) of the identifier or of the system (which is, for example, that of the vehicle). When the waiting is performed using an internal clock of the system, the method can include sending a message from the system to the identifier to tell it when to act. The waiting can be performed using the second measurement.

[0047] The triggered UWB communication may continue, for example, until the user enters the vehicle or starts the vehicle (e.g., starts the vehicle's engine). At that point, the UWB communication may vary. For example, the triggered UWB communication may include periodic UWB exchanges. When the user enters the vehicle or starts the vehicle, the frequency of these periodic UWB exchanges may decrease.

[0048] With reference to the flowchart in [Fig. 2], steps S60 to S90 are now discussed. In examples, the process may include these steps S60 to S90 after the execution of steps S10 to S50, and in particular after the user has entered the vehicle and completed the desired journey (e.g., a home-work, home-hotel, home-shop, or vice versa journey), i.e., once they have arrived at their destination. The process executes steps S60 to S90 after the user leaves the vehicle. The process may execute steps S60 to S90 while the user is traveling an exit route from the vehicle, i.e., from the vehicle to a place of stay (e.g., their home, office, hotel, or a business such as a shop or restaurant) and back 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.As with steps S10 to S50, steps S60 to S90 can each be performed by the handheld identifier, by the vehicle system, or by both devices (handheld identifier and vehicle system).

[0049] The S60 detection that the identifier leaves the predetermined security perimeter can be to be done in any way. For example, S60 detection can be based on distance measurements between the identifier and the system. Each distance measurement can be taken from a UWB exchange between the wearable identifier and the system, and can include calculating the 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 can include a distance and a position of the identifier around the vehicle. S60 detection can include comparing the measured distance with a distance corresponding to a radius of the predetermined safety perimeter. This distance can be specified in a manufacturer's standard. For example, it can be less than 3 meters and / or greater than 1 meter, for example, approximately 2 meters.

[0050] S70 suspension of the UWB communication is performed after S60 detection that the identifier leaves the predetermined safety perimeter.For example, the S70 suspension can be executed immediately after the S60 detection. The S70 suspension may include a reprogramming of UWB exchanges between the identifier and the system. The S70 suspension may also include a sleep mode for the identifier's UWB component.

[0051] In some examples, the S70 suspension may also include a record of the session parameters negotiated for the suspended UWB communication. Thanks to this record, the UWB communication can be reactivated (notably as in step S90) without renegotiating these session parameters, that is, by using the session parameters that were recorded during the S70 suspension and that will have already been negotiated during the S50 trigger. This improves the efficiency of the process.

[0052] After the S70 suspension, the method may include S80 monitoring of the RSSI (Received Signal Strength Indication) measurements of successive BLE exchanges. For example, the method may include performing successive BLE exchanges between the identifier and the system, and the S80 monitoring may include, for one or more of these BLE exchanges (for example, for all of these UWB exchanges), a measurement of the RSSI amplitude of that BLE exchange. For example, the method may monitor BLE exchanges performed every X milliseconds, with X between 30 milliseconds and 500 milliseconds, for example, approximately 300 milliseconds. The amplitude may be an amplitude measured at the reception of the signal exchanged during that exchange. For example, the amplitude may be measured at the reception of the signal at the wearable identifier or at the reception at the system.When the amplitude is measured by the vehicle's system, the latter can be configured to transmit the identifier.

[0053] Next, the monitoring may include, for each BLE exchange, a communication The method compares the amplitude measured for this exchange with the amplitudes measured for previous BLE exchanges. In examples, monitoring may include, for each BLE exchange, a comparison of the amplitude measured for that exchange with the amplitudes measured for all previous BLE exchanges (e.g., with each individual exchange or with an average of these measured amplitudes for previous BLE exchanges). Alternatively, the method may only compare the measured amplitude with the amplitude(s) measured at vehicle lock (e.g., with hysteresis in dB to account for inherent fluctuation in BLE operation). After each comparison, the method may include a recording of the measured amplitude (this amplitude is then used for comparison with the amplitude of the next signal).

[0054] When the comparison result is that the measured amplitude is lower than the amplitudes measured for previous BLE exchanges, the S80 monitoring may indicate that the user is still moving away from the vehicle. When the comparison result is that the measured amplitude is substantially equal to the amplitude of the last previous exchange(s), the S80 monitoring may indicate that the user is stationary. In this case, the method can continue S80 monitoring on subsequent exchanges to determine whether the user is turning back towards the vehicle or not.

[0055] When the comparison result shows that the measured amplitude is greater than the amplitudes measured for previous BLE exchanges, the S80 monitoring may indicate that the user is returning to the vehicle. In this case, the method includes reactivation (S90) of communication using the UWB communication protocol. Reactivation (S90) can be performed using the session parameters that were recorded during the S70 suspension and that will have already been negotiated during the S50 trigger, i.e., without renegotiating these parameters. Reactivation (S90) may include UWB exchanges between the identifier and the system using these already negotiated session parameters. These UWB exchanges can, for example, allow for distance measurements between the identifier and the system.This process allows UWB communication to be suspended and only reactivated when the user returns to the vehicle, thus contributing to improved energy efficiency for the wearable identifier.

[0056] Examples will now be described with reference to Figures 3 to 5.

[0057] Figure 3 illustrates an example of the use of the vehicle system according to the method. The figure shows the vehicle system 100 having registered the wearable identifier 200, 201, 202 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 boundary 321 of the BLE connection and boundary 311 of the UWB connection. Perimeters 310 and 320 are shown schematically in the figure, and this illustration does not represent the actual shape and scale of these perimeters. The second perimeter 320 includes the first perimeter 310.

[0058] The figure also shows the activities of the BLE component 400 and the UWB component 410 during the execution of the process. The figure also shows the activities of the motion sensor 420 and the microcontroller 430.

[0059] 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, S10, is a detection that the identifier is located within the second perimeter 320. The second step, S20, is performed after the detection S10 and before the user reaches the first perimeter 320, i.e., before point 202. The second step, S20, is a first 401 and a second 402 distance measurement between the user and the vehicle 100 using the BLE 400 communication protocol. The second measurement, 402, is performed after the first measurement, 401. The third step, S30, is a determination of the user's speed based on the first 401 and second 402 distance measurements.The fourth step, S40, is a prediction of the remaining time for the user to reach a predetermined near distance of 210, based on the determined speed. In this example, the predetermined near distance is 3 meters from the vehicle. The fifth step, S50, is the initiation of communication using the UWB communication protocol after the predicted remaining time has elapsed, i.e., at the time when it is predicted that the user will be at distance 210. The UWB communication initiation includes UWB 411 exchanges between the identifier and the vehicle.

[0060] The figure also illustrates steps S60 to S90 of the method, which are executed after the user leaves the vehicle. The method includes detection S60 when the identifier leaves a predetermined safety perimeter 330 around the vehicle. The first perimeter 310 includes this predetermined safety perimeter 330. In this example, the predetermined safety perimeter 330 includes all positions within 2 meters of the vehicle. After detection S60, the method includes suspension S70 of communication using the UWB communication protocol. Suspension S70 includes a halt 412 of UWB exchanges 411.

[0061] The method then includes S80 monitoring of RSSI measurements of successive BLE 403 exchanges executed after S60 deactivation of communication using the UWB communication protocol. S90 reactivation is not shown in the figure because the user continues to move away from the vehicle in this example. In other examples, during this S80 monitoring, the user may decide to return to the vehicle. For example, at position 204, the user might begin returning to vehicle 100. The S80 monitoring will then indicate that the user is now returning to the vehicle. For example, the monitoring might indicate that the user is returning to the vehicle when the RSSI measurements of successive BLE exchanges 403 increase. At this point, the process might include the S90 reactivation of communication using the UWB communication protocol.

[0062] Figure 4 illustrates a comparison of an example of the use of the 600 system. The vehicle is described in the method using the system according to an existing solution. The figure shows that in the existing solution 500, the UWB component must perform UWB communication trigger tests 411' as soon as the identifier enters the second perimeter 320. This is because the existing solution 500 performs these tests 411' to determine when the identifier is in the first perimeter 310 (one of the tests 411' then succeeding). In the method 600, these tests 411' are replaced by two distance measurements 401 and 402, which drastically reduces battery power consumption. In particular, when the near distance is less than the radius of the first perimeter (as in the illustrated example), the method 600 further reduces battery consumption because it also eliminates the first UWB exchange phase 412' of the existing solution 500.

[0063] When the user leaves the vehicle, the existing solution 500 includes UWB exchanges while the user is within the first perimeter. The method 600 avoids these UWB exchanges 414', since it suspends UWB communication as soon as the user leaves the security perimeter 412. This contributes to improving the lifespan of the power source. Furthermore, monitoring S80 using BLE exchanges 403 avoids the need for the UWB communication trigger tests 415' that are performed in the existing solution 500 when the identifier leaves the first perimeter 310, which also contributes to improving the lifespan of the power source.

[0064] Figure 5 illustrates an example of the 800 architecture of the wearable identifier. The 800 architecture comprises a UWB component 810, a BLE component 820, a microcontroller 840 integrating the BLE component 820, and internal communication 830 between the UWB component 810 and the BLE component 820 (via the microcontroller 840). The 800 architecture includes a UWB antenna 811 connected to the UWB component 810. The 800 architecture includes a BLE antenna 821 connected to the BLE component 820 (via the microcontroller 840). The internal communication 830 eliminates the need for the UWB component to integrate a time measurement component (e.g., a resonator). The 800 architecture includes a motion sensor 860 connected to the microcontroller 840. The 800 architecture includes a stack 850 powering the UWB component 810 and the microcontroller 840. After prediction S40, the process includes the The S50 trigger of the UWB communication. The S50 trigger involves the microcontroller 840 sending a wake-up signal to the UWB component 810 using internal communication 830. Upon receiving the wake-up signal, the UWB component 810 can start up by drawing power from the device's power source 850. This prevents the UWB component S810 from powering on when the user is not within the first perimeter, thus reducing the risk of unnecessarily consuming power from the power source 850.

Claims

Demands

1. A method of using a vehicle system having registered a portable identifier, the identifier comprising an electrical power source, the system and the identifier being 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 including the first perimeter, the method comprising, while a user wearing the identifier approaches the vehicle: • a detection (S 10) that the identifier is located in the second perimeter; • after the detection (S 10) and before the user reaches the first perimeter, an implementation (S20) of a first and a second distance measurement between the user and the vehicle using the BLE communication protocol, the second measurement being performed after the first measurement;• a determination (S30) of a user speed based on the first and second distance measurements; • a prediction (S40) of a remaining time for the user to reach a predetermined proximity distance from the vehicle based on the determined speed; and • a triggering (S50) of a communication using the UWB communication protocol after the predicted remaining time has elapsed.

2. A method according to claim 1, wherein the prediction comprises: • a calculation of a remaining distance between the distance measured by the second measurement and the predetermined near distance; and • a calculation of the remaining time corresponding to the time for the user to travel the remaining distance given the determined speed.

3. A method according to claim 1 or 2, wherein the method comprises, after the user leaves the vehicle: • a detection (S60) that the identifier leaves a perimeter of predetermined security around the vehicle, the first perimeter including the predetermined security perimeter; • a suspension (S70) of communication using the UWB communication protocol; • a monitoring (S80) of RSSI measurements of successive BLE exchanges executed after the deactivation of communication using the UWB communication protocol; and • a reactivation (S90) of communication using the UWB communication protocol when the monitoring indicates that the user is returning to the vehicle.

4. A method according to claim 3, wherein the monitoring indicates that the user returns to the vehicle when one or more of the RSSI measurements of successive BLE exchanges are greater than one or more of the RSSI measurements of previous BLE exchanges.

5. A method according to claim 3 or 4, wherein the successive monitored BLE exchanges comprise all BLE exchanges between the system and the identifier.

6. A method according to any one of the preceding claims, wherein the identifier comprises a microcontroller, a BLE component and a UWB component, the triggering (S50) 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.

7. 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.

8. 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 7.

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

10. Portable identifier and / or vehicle system comprising the storage medium according to claim 9, the portable identifier and / or the system being configured to perform the process according to any one of claims 1 to 7.

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