Location planning taking periodicity into account

Abstract

Title: Location Planning with Periodicity Consideration. A planning method implemented by a vehicle UWB system is proposed. The UWB system has stored a plurality of portable identifiers. Each portable identifier is configured to perform periodic UWB location sessions with the UWB system at a respective periodicity. The method includes a reception S10, for each portable identifier, of a respective programmed UWB location. The method includes a detection S20 of an overlay of UWB locations programmed with at least two portable identifiers. The method includes a determination S30 of a priority identifier. The priority identifier determined is the one with the longest periodicity. The method includes a deprogramming S40 of each UWB location included in the overlay other than the UWB location with the portable identifier determined as priority.The process offers improved utilization of the vehicle's UWB system. [Fig. 2].

Description

Title of the invention: Location planning taking periodicity into account. Technical field

[0001] This disclosure relates to a planning method implemented by a UWB (Ultra Wide Band) system, a method of using a UWB system, a UWB system configured to perform or be used according to such methods, a computer program for performing such methods, and a medium for such a program. Technical background

[0002] Vehicles equipped with a UWB system now exist, comprising one or more UWB anchors (also called sensors) installed in the vehicle. Such a UWB system typically records a set of portable identifiers (such as key fobs or third-party devices like mobile phones or smartwatches) and is then able to determine the position of each of these portable identifiers based on periodic UWB location checks between each of the portable identifiers and the system's UWB anchors. Such UWB systems are thus capable of simultaneously locating the driver's key fob and a passenger's mobile phone, and of executing various vehicle functions based on the location of the identifiers (such as unlocking the doors and / or starting the vehicle when a user approaches the vehicle).

[0003] To perform these location tracking, each wearable device can be configured to send its respective programming to the UWB system, for example, when the latter enters a certain perimeter around the vehicle. The UWB system and the wearable device can then be configured to perform the UWB location tracking according to the respective programming established. Figure 1 shows an example of such programming received for a set of two wearable devices: a first device with identifier 100 and a second device with identifier 200. In particular, the programming of the first device with identifier 100 includes UWB location tracking sequences 111, 112, and 113 performed according to a first periodicity, and the programming of the second device with identifier 200 includes UWB location tracking sequences 211, 212, and 213 performed according to a second periodicity.

[0004] When several locations are programmed simultaneously (i.e., in such a way that they would overlap if executed, the time intervals on which they are programmed having a non-zero intersection), existing scheduling methods generally retain only one location, and therefore include cancellation of all other locations UWB (for example, only the one programmed first can be retained). Such cancellation effectively reduces the risk of interference between the UWB exchanges of UWB locations if they were executed simultaneously. For example, in [Fig. 1], UWB location 112 of the first portable identifier 100 and UWB location 212 of the second portable identifier 200 are programmed at the same time, and the existing method therefore cancels the UWB location 212 programmed slightly later, so that, during execution, only the remaining UWB location 112 is executed.

[0005] One limitation is that these UWB location cancellations reduce the number of locations ultimately executed. In particular, they penalize one identifier over the others each time, which is especially problematic when the identifier has a long period and is blocked by an identifier with a shorter period. In such a situation, when several successive locations are canceled for an identifier, several seconds may elapse before the next location is executed, thus causing malfunctions in the vehicle's functionalities that use the identifier's position. For example, the user may approach the vehicle without it automatically unlocking, as is normally the case with this function.

[0006] Therefore, there is a need for an improved UWB location planning process. Summary

[0007] A planning method implemented by a vehicle UWB system (hereafter referred to as the "planning method" or "method") is proposed. The UWB system comprises one or more UWB anchors. The UWB system has stored a plurality of wearable identifiers. Each wearable identifier is configured to perform periodic UWB location sessions with the UWB system at a respective interval. The method includes receiving, for each wearable identifier, a respective schedule of UWB locations with the vehicle UWB system. The method includes detecting an overlap of the UWB locations scheduled with at least two wearable identifiers. The method includes determining a priority identifier from among the at least two wearable identifiers. The priority identifier determined is the one with the longest interval.The process includes deprogramming each UWB location included in the overlay other than the UWB location with the portable identifier determined as the priority.

[0008] The system can be configured to record, for each portable identifier, an associated priority score. The determination of the priority identifier includes a comparison of the priority scores of the portable identifiers involved in the overlay.

[0009] The priority score associated with each portable identifier can be proportional to the respective periodicity of the portable identifier.

[0010] For at least some of the portable identifiers, the respective periodicity may be equal to the product of a respective multiplier and a predetermined minimum duration. The priority score may be proportional to the respective multiplier of the portable identifier.

[0011] In the respective programming of at least one of the portable identifiers, each UWB location can be programmed within a respective slot of a respective period comprising several slots. The slot on which the UWB location is programmed can vary pseudo-randomly in each period.

[0012] Each UWB location with a portable identifier may include the transmission, by the portable identifier, of UWB frames, and the reception, by the UWB system, of the transmitted UWB frames. Deprogramming a UWB location may include canceling the vehicle's reception of the UWB frames transmitted by the portable identifier involved in the UWB location.

[0013] A method for using a vehicle UWB system (hereafter referred to as the "use method") is also proposed. The UWB system comprises one or more UWB anchors. The UWB system has stored a plurality of portable identifiers. The use method comprises executing the UWB locations planned according to the planning method.

[0014] A vehicle UWB system comprising one or more UWB anchors is also proposed. The UWB system is configured to perform the planning process. Alternatively or additionally, the UWB system is configured for use according to the usage process.

[0015] A computer program for a vehicle UWB system is also proposed. The computer program includes instructions which, when the program is executed by a processor of the vehicle UWB system, cause the latter to execute the planning process and / or to be used according to the operating process.

[0016] A computer-readable storage medium is also proposed on which said computer program is recorded. Brief description of the figures

[0017] Non-limiting examples will be described with reference to the following figures:

[0018] Fig. 1 illustrates an example of an existing UWB location planning solution with handheld devices.

[0019] Figure [Fig. 2] illustrates an example of a flowchart of the planning process.

[0020] Figure 3 illustrates an example of UWB location with a portable identifier.

[0021] Figure 4 illustrates an example of programming a UWB localization session periodicals.

[0022] Figure 5 illustrates an example of implementation of the processes.

[0023] Figures [Fig.6], [Fig.7] and [Fig.8] show examples of results obtained with and without use of the planning process.

[0024] Fig. 9 illustrates an example of a vehicle system.

[0025] Fig. 10 illustrates an example of a portable identifier. Detailed description

[0026] With reference to the flowchart in [Fig. 2], a planning method implemented by a vehicle UWB system (hereafter referred to as the "planning method" or "method") is proposed. The UWB system comprises one or more UWB anchors. The UWB system has stored a plurality of wearable identifiers. Each wearable identifier is configured to perform periodic UWB location sessions with the UWB system at a respective interval. The method includes a reception S10, for each wearable identifier, of a respective UWB location schedule with the vehicle UWB system. The method includes a detection S20 of an overlap of the UWB locations scheduled with at least two wearable identifiers. The method includes a determination S30 of a priority identifier from among the at least two wearable identifiers. The priority identifier determined is the one with the longest interval.The process includes an S40 deprogramming of each UWB location included in the overlay other than the UWB location with the portable identifier determined as priority.

[0027] The method offers improved utilization of the vehicle's UWB system.

[0028] Indeed, the method improves the localization of the different portable identifiers. In particular, in the event of overlapping locations, the method retains the one involving the portable identifier with the highest periodicity, thus avoiding an excessively long gap in localization for this identifier. This improves the localization of the portable identifiers. Indeed, on the one hand, it would have been particularly detrimental to the identifier with the highest periodicity not to retain its location, given its low localization frequency, and therefore the long period without localization induced until its next localization with the system. On the other hand, identifiers with lower periodicities are more likely to be able to perform another localization more quickly, and are therefore less penalized by this cancellation than the one with the highest periodicity.The process therefore allows overall a better distribution of locations with the different identifiers, and in particular avoids too long a break without location for identifiers with de. long intervals. The process therefore ultimately allows for the sensitive and precise location of all portable identifiers.

[0029] A method for using a vehicle UWB system comprising one or more UWB anchors is also proposed. The system has stored a plurality of portable identifiers. The method of use includes executing the UWB locations planned according to the planning process. At the time corresponding to the overlay detected during the planning process, the method of use therefore includes only the execution of the single location that is not deprogrammed with the portable identifier determined as the priority (and non-execution of the location(s) deprogrammed with the other identifier(s) involved in the overlay). The execution of a location may include performing the UWB exchanges between the portable identifier involved and the vehicle, for the location.

[0030] After or during the execution of the localization operations, the method of use may include determining the position of each of the wearable identifiers from the localization operations that have been performed. For example, for each wearable identifier, the execution of a localization operation involving the wearable identifier may include providing a relative position of the wearable identifier with respect to the UWB system. In particular, each localization operation may include UWB exchanges between the wearable identifier and one or more UWB anchors (also called "sensors") of the system (for example, all the anchors) to determine the respective distances between the wearable identifier and each of the anchors.Each location can then include a determination of the relative position of the portable identifier with respect to the UWB system from the determined distances (the position corresponding for example to the intersection of spheres drawn from the anchors and having as radii the calculated distances).

[0031] Each distance to an anchor can be measured by exchanging a UWB signal between the identifier and the anchor and calculating a time-of-flight between the identifier and the anchor during this exchange. This time-of-flight can be the time taken by the exchanged signal to travel to or from the identifier and the anchor. The time-of-flight can be calculated by the identifier or the anchor, 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 done by subtracting the time taken by the signal to travel to or from these recordings. Each measurement can then include subtracting the distance between the identifier and the anchor from this time-of-flight. For example, each measurement can include multiplying a signal velocity by the calculated time-of-flight. The signal velocity for example it can be a predetermined and known speed for this type of signal (for example stored in the memory of the identifier or the system).

[0032] The successive localizations performed during communication can allow the position of the wearable identifier to be determined in real time. For example, each localization can provide a position of the wearable identifier relative to the UWB system at a given instant, and the set of localizations performed can provide an evolution of its position over time. The method of use can thus include determining the evolution of the position of the wearable identifiers from the periodic UWB localizations performed.

[0033] The method of use may also include one or more uses of the determined relative positions of the portable identifier. For example, the method of use may include activating one or more vehicle functions depending on the position of the portable identifier. For example, the function may include locking the vehicle when it is determined that the portable identifier is outside the vehicle, for example, after a predetermined time has elapsed between the time it is determined that the portable identifier is outside. In some examples, the function may include selectively unlocking one or more vehicle openings (for example, a driver's door, a passenger door, or a vehicle trunk) depending on the determined relative positions of the portable identifier.For example, the functionality might include unlocking the driver's door or the vehicle's trunk when the wearable device approaches the driver's door or trunk. In other examples, the functionality might include activating one or more vehicle functions, such as turning on the music or adjusting the mirrors to suit the person wearing the wearable device, which is positioned near the driver's seat. The method of use could include any combination of these examples of functionality.

[0034] The planning process is now discussed. The steps of the planning process can be executed by the vehicle's UWB system. Each step of this process is now discussed in more detail.

[0035] The UWB system has recorded a plurality of portable identifiers (or wearable identifiers). The term "wearable identifier" refers to a mobile object identifiable by the vehicle, and whose location, for example, authorizes or prevents one or more (specific) actions of the vehicle. For example, the identifier can be used to unlock the vehicle and / or start the vehicle's engine. For example, the process can include unlocking the vehicle when the identifier is located near the vehicle, or starting the engine when the identifier is inside the vehicle. The wearable identifiers recorded by the system can include one or more vehicle remote key fobs. Alternatively or additionally, the portable identifiers registered by the system may include one or more third-party devices, that is, devices manufactured by a company other than the one that manufactures the vehicle's UWB system. For example, one or more third-party devices may include smart devices, such as mobile phones or smartwatches.

[0036] The vehicle and each wearable identifier can be configured to communicate using the UWB (Ultra Wide Band) communication protocol. UWB can refer to a communication protocol, for example, that specified by IEEE 802.15.4. This protocol may include an initialization phase with an exchange of communication parameters (such as the frequency of locations, the length of periods, the number of slots in each period, and / or the pseudo-random variation of location positions). The wearable identifiers can also be configured to communicate with the vehicle using the BLE (Bluetooth Low Energy) communication protocol.Some wearable identifiers (for example, all of them) can also be configured to communicate with the vehicle using one or more other communication protocols, such as the NFC (Near Field Communication) protocol. For each wearable identifier, UWB communication with the vehicle can only be initiated if a prior connection has been established using the BLE protocol.

[0037] The method comprises, for each portable identifier, an S10 reception of a respective UWB location programming with the vehicle's UWB system via one or more UWB anchors. The received programming may be numerical data. The respective programming received for each portable identifier may include numerical data defining a temporal positioning of each UWB location, for example, on a time axis (or line). For example, the respective programming received for each portable identifier may include numerical data defining start and end times for each UWB location specified on this time axis. The time axis may represent a future duration that has not yet elapsed at the time the programming is received.

[0038] Periodic UWB localizations are understood to be UWB localizations performed at fixed, more or less regular intervals. For example, the respective programming may include, for a set of successive periods (of approximately duration) equals), a UWB location for each period. The duration of these successive periods corresponds to the periodicity of the portable identifier.

[0039] In some examples, the location's position within each period may vary. This may be the case, for instance, for third-party device-type wearable identifiers. For example, each period may comprise an identical number of successive slots (of substantially equal duration), and the UWB location may be programmed within one of these slots. In this case, the received programming may include, for each UWB location, the slot number on which the UWB location is programmed. In some examples, the slot on which the UWB location is programmed may, for instance, vary pseudo-randomly within each period.Such pseudo-random variation further improves the localization of different portable identifiers, since it prevents the same overlap between portable identifiers from recurring several times regularly (such a situation can occur, for example, when the periodicities of the identifiers have common multiples). Indeed, when an overlap occurs in one period, the probability of having an overlap for the following period is low.

[0040] The pseudo-random variation at each period can, for example, follow a law whose parameters are known by the identifier and the vehicle. For example, the system and the portable identifier can initially exchange these parameters to each recover, using an algorithm, the pseudo-random distribution of locations at each period. The parameters of the law can be different for each identifier. The algorithm can, for example, use the following formula: S^KHOP Kev .\ = \\ Üi + HOP Kev | & OxFFFFf mod (2“ -15} i , »16 t — ' — RoiWKi ' (V\ — •- — J jvf} Round J

[0041] where i is the function index, HOP_Key is a parameter of this algorithm. This value allows differentiation between the various identifiers around the vehicle. The final entropy of this function is 216. The resulting distribution of the slot indices assigned for the different periods can be more or less uniform, for example, after a certain number of periods. To obtain an integer number of slots in each period, filler slots can be added to the end of each location.

[0042] Alternatively, the location position for each period can be fixed. This can be the case, for example, for portable identifiers such as key fobs. For example, UWB locations can be performed with a fixed frequency. When the periods are divided into slots, this amounts to placing each UWB location always on the same slot of each period (for example, the first). The received programming can in this case include the location frequency. (or the periodicity) and a start time of the first location, for example. In examples, the received programming may also include numerical data defining each of the UWB transmissions from each UWB location (for example, designating the start and end times of each UWB exchange from the UWB location).

[0043] Each registered handheld identifier can be configured to send its respective programming, which is received by the UWB system. Each registered handheld identifier can be within a given perimeter around the vehicle, allowing it to send its respective programming to the UWB system. The respective programming can be sent by the handheld identifiers and received by the UWB system using a companion communication protocol (such as the BLE communication protocol). The UWB system may also have registered one or more other handheld identifiers (or devices), which may, for example, currently be out of range. The consideration of these other handheld identifiers when they come within range of the vehicle is discussed later.

[0044] After or during the S10 reception, the method may include recording all received programming, for example, in system memory. The programming received for each handheld identifier may include the periodicity of the handheld identifier (i.e., the duration of each period), the number of slots per period, and / or the duration of each slot or period. For each period, the programming may also include an indication of the slot on which the UWB location is programmed for that period (this slot may vary randomly from period to period or be fixed). This information may be specific to the handheld identifier. The handheld identifier may be configured to enforce certain parameters of its programming.

[0045] Each UWB location may include UWB exchanges between the portable identifier and the system's UWB anchors. Each UWB exchange may consist of frame transmissions between the identifier and one or more UWB anchors. In particular, each UWB location with a portable identifier may include the transmission of UWB frames by the portable identifier, followed by the UWB system listening for the transmitted UWB frames. The programming received for each portable identifier may include, for each programming location, a time position of the transmission and reception times of the frames exchanged between the system and the portable identifier. Each frame transmission may, for example, have a duration of between 60 and 137 microseconds.

[0046] After reception S10, the method includes detection S20 of the overlap of UWB locations programmed with at least two portable identifiers. By overlapped UWB locations, we mean locations that are programmed on time intervals having a non-zero intersection. For example, the time slot in which a first UWB location involving a first portable identifier is scheduled may end after the start of the time slot in which a second UWB location involving a second portable identifier is scheduled.

[0047] The S20 detection of the overlap can be performed in any manner. For example, the S20 detection of the overlap can comprise the following two steps. A first step can comprise a projection of the UWB locations of each of the wearable identifiers onto a common time axis. The projection of the UWB locations can include, for each UWB location, an indication of the start and end times of the UWB location on this common time axis. A second step can comprise a determination of an overlap between the projections of the at least two overlapping UWB locations. The determination of the overlap can be performed using the start and end times indicated on the axis for each UWB location.For example, determining the overlap may include determining that the start time of the slot on which the second UWB location involving the second portable identifier is programmed is located before the end time of the slot on which the first UWB location involving the first portable identifier is programmed.

[0048] After detection S20, the method includes determining S30 a priority identifier from among the at least two portable identifiers involved in the detected overlay. The determination S30 of the priority identifier can be performed in any way. For example, the system can register certain portable identifiers as priority, and, when the overlay includes one of these identifiers, deprogram all other identifiers.

[0049] In some examples, the system can be configured to record, for each wearable identifier, a priority score associated with the wearable identifier. The system may, for example, include memory in which is stored a table listing the priority scores associated with the different wearable identifiers, that is, the value of the priority score for each identifier. The priority scores can be any type of mutually comparable value. The priority score of each wearable identifier can correspond to a value in a predetermined set of ordered values. The scores of the identifiers can thus be compared with each other according to the order of their values ​​in this set. For example, the priority scores can be digits (e.g., "1", "2", "3",...), real numbers (e.g., "1,2", "2,4",...), colors (e.g., "green", "yellow", "red",...) or words (e.g., "strong", "medium", and "weak"). In this case, the S30 determination of the priority identifier may include a comparison of the priority scores of the portable identifiers. involved in the overlay. The comparison may include determining the identifier with the highest priority score. This identifier is the one determined to have priority. If several identifiers have the same priority score and this one is the highest, the process can determine the priority identifier among these identifiers in any way (for example, randomly, or based on their periodicity).

[0050] In some examples, the priority score associated with each wearable identifier can be proportional to the respective periodicity of the wearable identifier. In other words, the priority score of each wearable identifier can be inversely proportional to the frequency of UWB locations performed with the wearable identifier. The use of such a priority score improves the selection of the priority identifier and thus ultimately allows for better regulation of locations with different wearable identifiers in the event of overlap.

[0051] In examples, for at least some of the wearable identifiers, the respective periodicity may be equal to the product of a respective multiplier (called the "RAN multiplier") and a predetermined minimum duration. For example, the wearable identifier may be configured to perform a location update at each successive time interval of duration T (T being the periodicity of the wearable identifier). In this case, the duration T may be equal to nRAX x Atmini, where nRAX is the respective multiplier of the identifier and Atmini is the predetermined minimum duration. The multiplier may be an integer. The predetermined minimum duration Atmini may be defined by a standard (for example, 96 ms) and may be the same for all the wearable identifiers concerned.In this case, the priority score of each portable identifier can be proportional to the respective multiplier coefficient nRAN of the portable identifier. The respective multiplier coefficient can be initially negotiated by each identifier with the system, for example during the preliminary phase.

[0052] After the S30 determination of the priority identifier, the method includes the S40 deprogramming of the overlapping UWB location(s) other than the one with the priority portable identifier. In other words, the method deprograms all overlapping UWB locations other than the one with the identifier determined to be priority. For example, if two locations with two identifiers are overlapped, the method deprograms the one with the lower priority identifier. The deprogramming may include reversing steps that the system would otherwise perform if the location were retained. For example, the deprogramming may include preventing the vehicle from listening to UWB frames sent by The wearable device involved in UWB location tracking. The wearable device may not be aware that its programming has been cancelled.

[0053] In examples, the method can detect several overlaps of UWB locations in the respective programming of the portable identifiers. In this case, the method can repeat, for each of the detected overlaps, the steps S30 of determining a priority portable identifier among those involved, and of deprogramming S40 the locations with the other portable identifier(s) in order to resolve the overlap problem at each detected overlap. The steps S30 and S40 can, in this case, be executed as previously discussed, considering each time a new overlap of UWB locations (and potentially new identifiers involved).

[0054] In examples, steps S20 to S40 can be repeated each time a new programming is received for a new wearable identifier. For example, this new wearable identifier may initially be out of range of the vehicle, and the user wearing it may approach the vehicle. This new identifier may also be registered by the UWB system (in addition to the others). As the user approaches the vehicle, once the new identifier enters a certain perimeter around the vehicle, the new identifier can be configured to begin locating the vehicle. To do this, the new identifier can be configured to send its respective programming to the UWB system. The method may then include receiving this respective programming for this new identifier (as for the other identifiers in step S10).In this case, the process may include a repetition of steps S20 to S40 with the respective new programming received for this new identifier. For example, detection S20 may include detecting a new overlap between at least two locations, one of which involves the new identifier, and then deprogramming or not this location depending on whether this new identifier has priority over the others involved.

[0055] Examples will now be described with reference to Figures 3 to 10.

[0056] Figure 3 illustrates an example of UWB localization with a portable identifier. Localization includes UWB exchanges between the portable identifier and the vehicle system (the UWB exchanges consisting of frame transmissions between the identifier and the system's UWB anchors). UWB localization begins with the portable identifier sending UWB frames to the UWB anchors. In particular, localization initially comprises two 410 transmissions of a frame in the first two time slots from the identifier to each of the UWB anchors 401, 402, and 403. Each slot can last between 1 and 3 ms. Each slot is, for example, 2 ms in this example. Localization includes listening, by the UWB anchors, to These UWB 410 frames are sent by portable identifier 400 during the first two time slots. After this initial phase, the anchors respond by successively sending their respective frames to the portable identifier. Specifically, the localization process involves, successively and within a respective time slot, the transmission of a frame by each of the UWB anchors (frame 412 for 401, frame 413 for 402, and frame 414 for 403) to portable identifier 400. The portable identifier is configured to listen for and receive these frames 412, 413, and 414 sent successively by the anchors. The localization process then involves two transmissions, 415, by identifier 400, of a frame during the last two time slots to each of the UWB anchors 401, 402, and 403 of the system. These two sent frames are listened to and received by portable identifier 400.

[0057] The duration of each UWB location “RR_thne” can be calculated from the following formula: RR_time = Ranging_Slot_Time * ( Number_of_Responder + 4), where “Ranging_Slot_Time” is the duration of each slot and “Number_of_Responder” is the number of anchors in the system.

[0058] The localization process then includes determining the distances between the portable identifier 400 and each of the UWB anchors 401, 402, and 403 of the system. Each distance to an anchor can be measured from the UWB frames exchanged between the portable identifier and the anchor and a time-of-flight calculation between the identifier and the anchor. This time-of-flight is the time taken for each frame to travel to or from the identifier and the anchor. The time-of-flight can be calculated by the identifier or the anchor, and can be performed in any way. For example, each measurement can include recordings of the times the exchanged frames were sent and received, and the calculation can be performed by subtracting the time taken by each frame to travel to or from these recordings. Each measurement can then include subtracting this time-of-flight from the distance between the identifier and the anchor.For example, each measurement can involve multiplying the speed of the signal carrying the UWB frame by the calculated time of flight. The signal speed can be a predetermined and known speed (e.g., stored in the identifier or system memory). The signal speed, i.e., the propagation speed of UWB waves, can be the speed of light (a constant stored in memory).

[0059] The localization process then includes determining the relative position of the wearable identifier with respect to the UWB system based on the determined distances. In particular, the position determination includes determining the intersection of spheres calculated on a plane representing the ground on which the car is located and on which the user wearing the identifier is walking. The spheres originate from the system's anchors and have radii equal to the calculated distances.

[0060] The deprogramming of such a location is now discussed. A location is executed by both the system and the identifier. However, the system can cancel a location without informing the identifier. The system may, in fact, only manage one location at a time. Each identifier manages its locations through a specific session. During an overlay, the session containing the first programmed location is executed, and the second session waits for the next period to attempt a location between the portable identifier and the vehicle's anchors.

[0061] To cancel a location with an identifier, the system can, for example, cancel listening to the frames sent by the portable identifier. For example, the cancellation could include canceling listening to the first 410 frames sent by the identifier to each of the anchors. In some examples, the cancellation could also include canceling the sending of the 412, 413, and 414 frames successively transmitted by each of the anchors thereafter, and / or canceling listening to the last 415 frames sent by the identifier 400.

[0062] Figure 4 illustrates an example of programming a session of periodic UWB locations between a handheld identifier and a UWB system. During the session, the periodic UWB locations of the UWB locations are performed at fixed, more or less regular intervals. The respective programming comprises, for a set of successive periods (of substantially equal duration), one UWB location for each period. The duration of these successive periods corresponds to the periodicity of the handheld identifier.

[0063] In some examples, the position of the location within each period can vary. Each period 422 can comprise an identical number of successive slots 424 (of substantially equal duration), and the UWB location can be programmed within one of these slots 424. In some examples, the slot on which the UWB location is programmed can, for instance, vary pseudo-randomly within each period. Alternatively, the position of the location within each period can be fixed. For example, each UWB location can always be performed within the same slot of each period (for example, the first one). Each slot 424 is itself divided into time intervals (called "slots"). The location can include UWB exchanges between the wearable identifier and the system within each of these time intervals.

[0064] Figure 5 illustrates an example of implementation of the methods. The figure shows, in particular, the respective programs received in this example from four portable identifiers 431, 441, 451, and 461. The respective program of each portable identifier includes periodic UWB locations. In particular, the programs include, for a set of periods successive periods divided into successive slots, with one location per period within one of the slots of that period. The slot on which the location is performed varies pseudo-randomly for each period for all three identifiers.

[0065] The figure illustrates, in particular, the initial planned locations over the first successive periods for each of the identifiers. For the first identifier 431, the figure shows the first three locations 435, 436, 437 distributed over three successive periods 432, 433, 434. For this identifier, each period is divided into 8 slots, and each location is implemented within one of these slots during each period. As illustrated in the figure, the first location 435 is implemented in the first slot for the first period 432, the second location 436 is implemented in the fifth slot for the second period 433, and the third location 437 is again implemented in the first slot for the third period 434.

[0066] Each period is also divided into 8 slots for the second portable identifier 441. However, the localizations are not performed on the same slots. Indeed, the localization is performed on the first slot for the first period 442, but on the second slot for the second period 443 and on the third slot for the third period 444.

[0067] For the third device 451, the number of slots per period is 3. Location is performed on the first slot for the first period 452, on the second for the second period 453, and on the third for the third period 454. The slots have a longer duration than those of the first and second identifiers. The fourth portable identifier 461 has a program with longer periods, with 9 slots of approximately the same duration as the third 451. The first location is also performed on the first slot for the first period 462.

[0068] In this example, the first three identifiers 431, 441, and 451 have periodicities of approximately the same duration. Their location frequency is therefore approximately the same. In contrast, the fourth portable identifier 461 has a longer periodicity. It therefore has a higher priority score than the others. In case of overlap, the scheduling process thus prioritizes its locations. For example, the process includes an S20 detection of the overlap of UWB locations 435, 445, and 463 programmed with portable identifiers 431, 441, and 461. The process includes an S30 determination that identifier 461 has priority among portable identifiers 431, 441, and 461. Indeed, it is the one with the longest periodicity.The process then includes an S40 deprogramming of each UWB location included in the overlay other than UWB location 463 with portable identifier 461 determined as priority, i.e. a . deprogramming of location 435 with the first portable identifier 431 and of location 445 with the second priority identifier 441. The locations thus programmed are then executed during the usage process.

[0069] The method thus offers improved use of the vehicle's UWB system. Indeed, preserving the location 463 involving the portable identifier with the highest periodicity 461 avoids an excessively long gap in location for this identifier 463. Otherwise, it would have been particularly detrimental to this identifier 461 not to preserve its location, given its low location frequency, and therefore the long period without location that would otherwise result until its next location with the system. On the other hand, the other identifiers 431, 441, and 451 have shorter periodicities. They are more likely to be able to achieve a location more quickly than identifier 461, and are therefore less penalized by this cancellation.They each still have two programmed locations within the time interval shown in the figure, and therefore have two more chances to perform a location with the system despite the cancellation of their first location. The process thus allows for a better distribution of locations among the different identifiers, and enables the sensitive and precise location of all portable identifiers.

[0070] Figures 6 and 7 show examples of results obtained in two different situations involving different types of wearable identifiers. These results were obtained by simulating the different situations illustrated. In both situations, five wearable identifiers are simulated around the vehicle. The simulation is performed using a Python program to simulate, by a Monte Carlo method, location sessions executed simultaneously (with a random offset of less than one period) to measure the overlap rate. The characteristics of the wearable identifiers used are given in Table 1 below.

[0071] [Tables 1] Portable identifier, Multiplier coefficient, Average periodicity, Slot length: Manufacturer A 3,288 ms 2 ms, Manufacturer B 2,192 ms 1 ms, Manufacturer C 1,96 ms 1 ms

[0072] Figure 6 shows, in these two situations, the results obtained without the use of the planning process, and [Fig. 7] the results obtained when the planning process is used. The tables representing the different situations indicate, in particular, for each identifier involved, the longest duration. Without identifier location (column "Max (ms)"), the percentage of times more than one second elapsed between two locations (column "> 1s") and the identifier priority (column "priority") are considered. When the scheduling process is not used, in the case of overlap, all identifiers are considered to have the same priority, and only the first location (which starts before the others) is retained. In this case, the results show that the percentages of times more than one second elapsed between two locations are significant for long-period identifiers. For example, they are greater than 3% for the first three identifiers in the first 501 situation, and greater than 1% in the second 503 situation.

[0073] When the planning process is used, the process assigns a priority score that is a function of the periodicity. Specifically, in the first situation 511, the process assigns a score of 50 to the first three identifiers, but assigns a score of 0 to the last two, which have a shorter periodicity. Similarly, in the second situation 513, the process assigns a higher priority score to the first three identifiers, which have a longer periodicity, than to the last two. The results show that the planning process makes it possible to obtain a percentage of times when more than one second elapsed between two locations of less than 1% for all identifiers in these two situations. In particular, the probability of having a waiting time greater than one second is reduced by a factor of seven for identifiers with a longer periodicity.The planning process therefore allows for the sensitive and precise localization of all portable identifiers, avoiding excessively long gaps in localization for those with the longest intervals. In particular, the process yields better results than reducing the performance of devices with the shortest intervals.

[0074] Figure 8 shows examples of results obtained using the planning method in a situation where two key fobs and three third-party devices (smartphones) are located around the vehicle. In particular, the figure shows the evolution of the percentage of times more than one second elapsed between two locations (Y-axis) for each of these five identifiers. The figure also shows the evolution of this percentage as a function of the periodicity of the first of the two key fobs (X-axis). The figure shows the evolution of this percentage for a third-party device from manufacturer A 703, a third-party device from manufacturer B 704, a third-party device from manufacturer C 705, the first key fob 701, and a second key fob 702. The third-party devices have the characteristics indicated in Table 1.

[0075] These results are obtained by simulating 10,000 periods of 30 seconds with different periodicities for the two key fobs. Third-party devices have Priority scores are a function of their periodicity. Specifically, the longer the periodicity of an identifier, the higher its score. In this example, the periodicity of each tier device is equal to the product of the tier device's multiplier (the "RAN multiplier") and a predetermined duration of 96 ms. The priority score for each tier device is proportional to its multiplier. In particular, the priority score Pi of each tier device i is calculated using the following formula: Pi = C x (nRAN, i - 1), where nRANi is the respective multiplier of tier device i and C is a predetermined coefficient (equal to 20 in this example). Key fobs have a score equal to that of the tier device with the longest periodicity.

[0076] Tier A device 703 has the highest periodicity (288 ms), with a multiplier of 3. It therefore also has the highest priority score (40). Tier B device 704 has a medium periodicity (192 ms) with a multiplier of 2. It therefore has a medium priority score (20). Tier C device 704 has a short periodicity (96 ms) with a multiplier of 1. It therefore has a low priority score (20). In case of overlap, Tier A device will have priority over the other two, and Tier B device will have priority over Tier C device. The figure shows that the method thus makes it possible to obtain, for each of these identifiers, a low percentage of times where more than one second has elapsed between two locations (in particular, less than 1% for all three devices).The planning process therefore makes it possible to locate these three identifiers with sensitivity and precision.

[0077] Figure 9 illustrates an example of a vehicle system 10. The system 10 is configured to implement the planning process. In this example, the system includes several secondary UWB sensors (or anchors) 11 connected to a private CAN (Controller Area Network) 12. The secondary UWB sensors 11 are internal to the vehicle. The system also includes a primary sensor (or anchor) 13, which is a master unit for the system. Each UWB sensor includes means for transmitting and receiving UWB exchanges (such as one or more transmitting and / or receiving antennas for such UWB exchanges), with wearable identifiers, for example, to perform UWB location tracking of these wearable identifiers. The system also includes an NFC reader 14. The system supports Bluetooth technology. The primary anchor 13 and the NFC reader 14 are also connected to the system's network 12.

[0078] Figure 10 illustrates an example of a portable identifier 310. The portable identifier 310 may, for example, be a vehicle remote key fob housing. Such a vehicle remote key fob housing may include a protective case enclosing the key fob components. The protective case may comprise material The key fob can be made of plastic, metal, and / or rubber. The 310 key fob may include a logo, for example, made of metal. The logo may be placed on the outer casing of the protective housing, and / or the logo may represent a manufacturer's brand. Such a key fob may also include a metal insert inside the protective housing, which allows the vehicle to be opened and / or started manually by inserting and manipulating the insert into a respective lock on the vehicle.

[0079] The handheld identifier 310 includes a BLE component 312, configured to perform BLE communication with a vehicle, and comprising, for example, a microprocessor. The handheld identifier 310 also includes an antenna 316 connected to the BLE component 312. The antenna 316 is configured to transmit or receive BLE signals. The microprocessor of the BLE component 312 may have in memory a computer program enabling BLE communication and performing various specific functions. The handheld identifier 310 also includes a UWB component 311 for performing UWB communication with a vehicle. The handheld identifier 310 also includes a battery 313.

Claims

Demands

1. A planning method implemented by a vehicle UWB system comprising one or more UWB anchors, the UWB system having registered a plurality of portable identifiers, each portable identifier being configured to perform a respective session of periodic UWB locations with the UWB system at a respective periodicity, the method comprising: • a reception (S10), for each portable identifier, of a respective programming of UWB locations with the vehicle UWB system; • a detection (S20) of an overlap between UWB locations programmed with at least two portable identifiers; • a determination (S30) of a priority identifier among the at least two portable identifiers, the priority identifier determined being the one having the longest periodicity;and • a deprogramming (S40) of each UWB location included in the overlay other than the UWB location with the portable identifier determined as priority.;

2. A method according to claim 1, wherein the system is configured to record, for each wearable identifier, an associated priority score, the determination (S30) of the priority identifier comprising a comparison of the priority scores of the wearable identifiers involved in the overlay.

3. A method according to claim 2, wherein the priority score associated with each portable identifier is proportional to the respective periodicity of the portable identifier.

4. A method according to claim 2 or 3, wherein, for at least some of the wearable identifiers, the respective periodicity is equal to the result of the product of a respective multiplier coefficient and a predetermined minimum duration, the priority score being proportional to the respective multiplier coefficient of the wearable identifier.

5. A method according to any one of the preceding claims, wherein, in the respective programming of at least one of the portable identifiers, each UWB location is programmed to within a respective slot of a respective period including several slots, the slot on which the UWB location is programmed varying pseudo-randomly in each period.

6. A method according to any one of the preceding claims, wherein each UWB location with a portable identifier comprises: • sending, by the portable identifier, UWB frames; and • listening, by the UWB system, to the UWB frames sent, the deprogramming (S40) of a UWB location comprising canceling the listening by the vehicle of the UWB frames sent by the portable identifier involved in the UWB location.

7. Method of using a vehicle system comprising one or more UWB anchors, the system having recorded a plurality of portable identifiers, the method comprising an execution of the planned UWB locations according to the method of any one of claims 1 to 6.

8. Vehicle system comprising one or more UWB anchors and configured to perform the method of any one of claims 1 to 6 and / or to be used according to the method of claim 7.

9. Computer program comprising program code instructions for carrying out the process according to any one of claims 1 to 6 and / or according to claim 7, when said program is executed by a processor.

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

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