Location scheduling with consideration of periodicity

Abstract

The invention relates to a scheduling method implemented by a vehicle UWB system; the UWB system has registered a plurality of portable identifiers. Each portable identifier is configured to perform periodic UWB localization sessions with the UWB system according to a respective periodicity. The method comprises receiving, S10, for each portable identifier, a respective scheduling of UWB localizations. The method comprises detecting, S20, an overlap between the scheduled UWB localizations with at least two portable identifiers. The method comprises determining, S30, a priority identifier. The determined priority identifier is the one having the longest periodicity. The method comprises descheduling, S40, each UWB localization included in the overlap other than the UWB localization with the portable identifier determined as the priority identifier. The method provides improved use of the vehicle UWB system.

Description

Description Title of the invention: Location planning taking into account periodicity 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 within the vehicle. Such a UWB system typically registers a set of wearable 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 wearable identifiers based on periodic UWB location checks between each wearable identifier 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 identifier locations (such as unlocking the doors and / or starting the vehicle when a user approaches).

[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 system enters a certain perimeter around the vehicle. The UWB system and the wearable device can then be configured to perform UWB location tracking according to the established programming. Figure 1 shows an example of such programming received for a set of two wearable devices: a first device with ID 100 and a second device with ID 200. Specifically, the programming for the first device with ID 100 includes UWB locations 111, 112, and 113 performed at a first interval, and the programming for the second device with ID 200 includes UWB locations 211, 212, and 213 performed at a second interval.

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

[0005] One limitation is that these UWB location cancellations reduce the number of locations ultimately executed. Specifically, they penalize one identifier over the others each time, which is particularly 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 can elapse before the next location is executed, thus causing malfunctions in the vehicle's functionality that relies on the identifier's position. For example, the user might 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] We propose a planning method implemented by a vehicle UWB system (hereafter referred to as the "planning method" or "method"). The UWB system includes one or more UWB anchors. The UWB system has registered 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 The method involves reprogramming UWB locations with the vehicle's UWB system. It includes detecting an overlap of UWB locations programmed with at least two portable identifiers. The method includes determining a priority identifier from among the at least two portable identifiers. The priority identifier determined is the one with the longest periodicity. The method includes deprogramming each UWB location included in the overlap, other than the UWB location with the portable identifier determined to have priority.

[0008] The system can be configured to record an associated priority score for each wearable device. Determining the priority identifier involves comparing the priority scores of the wearable devices involved in the overlay.

[0009] The priority score associated with each portable identifier may 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 within each period.

[0012] Each UWB location with a portable identifier can 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 can include canceling the vehicle's reception of UWB frames transmitted by the portable identifier involved in the UWB location.

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

[0014] A vehicle-mounted UWB system comprising one or more UWB anchors is also offered. The UWB system is configured to execute the planning process. Alternatively or additionally, the UWB system is configured for use according to the utilization process.

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

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

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

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

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

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

[0021] Figure 4 illustrates an example of programming a session of periodic UWB localizations.

[0022] Figure 5 illustrates an example of process implementation.

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

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

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

[0026] Referring to the flowchart in Figure 2, a planning method implemented by a vehicle UWB system (hereafter referred to as the "planning method" or "method") is proposed. The UWB system includes 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 an S10 reception, for each wearable identifier, of a programming The method involves the reprogramming of UWB locations with the vehicle's UWB system. It includes an S20 detection of an overlay of UWB locations programmed with at least two portable identifiers. The method includes an S30 determination of a priority identifier from among the at least two portable identifiers. The priority identifier determined is the one with the longest periodicity. The method includes an S40 deprogramming of each UWB location included in the overlay, other than the UWB location with the portable identifier determined to have priority.

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

[0028] Indeed, the process improves the localization of different portable identifiers. In particular, when several locations overlap, the process retains the one involving the portable identifier with the highest periodicity, thus preventing an excessively long gap in localization for that identifier. This improves the localization of portable identifiers. On the one hand, it would have been particularly detrimental to the identifier with the highest periodicity not to retain its localization, given its low localization frequency and the resulting long period without localization until its next localization with the system. On the other hand, identifiers with lower periodicities are more likely to be able to establish another localization more quickly and are therefore less penalized by this cancellation than the one with the highest periodicity.The process therefore generally allows for a better distribution of locations across different identifiers, and in particular avoids excessively long gaps in tracking for identifiers with high frequency intervals. Ultimately, the process thus enables the sensitive and precise location tracking of all portable identifiers.

[0029] We also propose a method for using a vehicle UWB system comprising one or more UWB anchors. 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 executing the single location that is not deprogrammed with the portable identifier determined to have priority (and not executing the location(s) deprogrammed with the other identifier(s) involved in the overlay). The execution of a location may include a implementation of UWB exchanges, between the portable identifier involved and the vehicle, of the location.

[0030] After or during the execution of the localization operations, the usage process may include determining the position of each wearable identifier (WI) based on the localization operations that have been performed. For example, for each WI, the execution of a localization operation involving the WI may include providing a relative position of the WI with respect to the UWB system. In particular, each localization operation may include UWB exchanges between the WI and one or more UWB anchors (also called "sensors") of the system (for example, all anchors) to determine the respective distances between the WI 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 (TOF) between the identifier and the anchor during this exchange. This TOF can be the time taken by the exchanged signal to travel to or from the identifier and the anchor. The TOF can be calculated by either the identifier or the anchor, and can be performed in any way. For example, each measurement could include recordings of the times the exchanged signal was sent and received, and the calculation could be done by subtracting the signal's TOF travel from these recordings. Each measurement could then include subtracting the distance between the identifier and the anchor from this TOF. For example, each measurement could include multiplying a signal velocity by the calculated TOF.The signal speed can, for example, be a predetermined and known speed for this type of signal (for example, stored in the identifier or system memory).

[0032] Successive location checks performed during the communication can allow the position of the wearable identifier to be determined in real time. For example, each location check can provide a position of the wearable identifier relative to the UWB system at a given moment, and the set of all performed locations can to provide an evolution of its position over time. The method of use may thus include determining the evolution of the position of portable identifiers from periodic UWB location tracking.

[0033] The usage process may also include one or more uses of the determined relative positions of the wearable identifier. For example, the usage process may include activating one or more vehicle features based on the wearable identifier's position. For example, the feature may include locking the vehicle when it is determined that the wearable identifier is outside the vehicle, for example, after a predetermined time has elapsed between the time it is determined that the wearable identifier is outside. In some examples, the feature may include selectively unlocking one or more vehicle openings (for example, a driver's door, a passenger's door, or a vehicle trunk) based on the determined relative positions of the wearable identifier.For example, the functionality might include unlocking the driver's door or the vehicle's trunk when the wearable device approaches the 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 registered a plurality of portable identifiers (or wearable identifiers). The term "wearable identifier" refers to a mobile object identifiable by the vehicle, and whose location may or may not authorize one or more (specific) vehicle actions. For example, the identifier may be used to unlock the vehicle and / or start the vehicle's engine. For example, the process may 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 registered by the system may include one or more key fobs. vehicle remote control. Alternatively or additionally, the wearable identifiers registered by the system may include one or more third-party devices, that is, devices manufactured by a company other than the one manufacturing 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 device can be configured to communicate using the UWB (Ultra Wide Band) communication protocol. UWB can refer to a communication protocol, such as the one specified by IEEE 802.15.4. This protocol may include an initialization phase with an exchange of communication parameters (such as the location frequency, period length, number of slots in each period, and / or the pseudo-random variation of location positions). The wearable devices can also be configured to communicate with the vehicle using the BLE (Bluetooth Low Energy) communication protocol.Some wearable devices (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 device, UWB communication with the vehicle can only be initiated if a prior connection has been established using the BLE protocol.

[0037] The method includes, for each wearable 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 numeric data. The respective programming received for each wearable identifier may include numeric 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 wearable identifier may include numeric data defining start and end times for each UWB location specified on this time axis. The time axis may represent a future duration which has not yet elapsed at the time of receipt of the programming.

[0038] Periodic UWB locations are defined as UWB locations performed at fixed, more or less regular intervals. For example, the respective programming might include, for a set of successive periods (of approximately equal duration), one 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 can vary. This can be the case, for instance, with third-party device-type wearable identifiers. For example, each period might contain the same number of successive slots (of roughly equal duration), and the UWB location could be programmed within one of these slots. In this case, the received programming might 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 might, 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 wearable identifier can initially exchange these parameters to each determine, 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: OxFFfrf mo 16 - Is #? » 16

[0041] where i is the function index, HOP_Key is a parameter of this algorithm. This value allows differentiation between the different identifiers around the vehicle. The final entropy of this function is 2 16The resulting distribution of slot indices assigned for the different periods can be more or less uniform, for example, after a certain number of periods. To have a whole number of slots in each period, filler slots can be added to the end of each location.

[0042] Alternatively, the location position within each period can be fixed. This can be the case, for example, with portable identifiers such as key fobs. For instance, UWB locations can be performed with a fixed frequency. When periods are divided into time slots, this means that each UWB location is always positioned within the same time slot of each period (for example, the first). The received programming can then include the frequency of the locations (or the periodicity) and a start time for the first location, for example. In some examples, the received programming can 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 for the UWB location).

[0043] Each registered wearable device can be configured to send its respective programming, which is received by the UWB system. Each registered wearable device can be within a certain radius of the vehicle, allowing it to send its programming to the UWB system. The respective programming can be sent by the wearable devices 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 wearable devices, which may, for example, currently be out of range. The consideration of these other wearable devices when they come within range of the vehicle is discussed later.

[0044] After or during S10 reception, the method may include recording all received programming, for example, in system memory. The received programming for each portable identifier may include the periodicity of the portable 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 The time slot during which UWB location tracking is programmed for this period (this slot may vary randomly or be fixed). This information may be specific to the wearable device. The wearable device can be configured to enforce certain programming parameters.

[0045] Each UWB location can include UWB exchanges between the portable identifier and the system's UWB anchors. Each UWB exchange can consist of frame transmissions between the identifier and one or more UWB anchors. In particular, each UWB location with a portable identifier can 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 can 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 can, for example, have a duration between 60 and 137 microseconds.

[0046] After the S10 reception, the method includes the S20 detection of overlapping UWB locations programmed with at least two portable identifiers. Overlapping UWB locations are defined as locations programmed over time intervals that have a non-zero intersection. For example, the time slot in which a first UWB location involving a first portable identifier is programmed may end after the start of the time slot in which a second UWB location involving a second portable identifier is programmed.

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

[0048] After detection S20, the process 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 store, for each wearable device, a priority score associated with that device. The system might, for instance, include memory containing a table listing the priority scores associated with the different wearable devices—that is, the priority score value of each device. Priority scores can be any type of mutually comparable value. The priority score of each wearable device can correspond to a value within a predetermined set of ordered values. The scores of the devices can thus be compared based on the order of their values ​​within this set. For example, priority scores could be digits (e.g., "1", "2", "3", ...), real numbers (e.g., "1,2", "2,4", ...), or colors (e.g., "green", "yellow", "red", ...).) or words (for example, "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 be the priority identifier. If several identifiers have the same priority score and this one is the highest, the process may 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 wearable identifier's respective periodicity. In other words, the priority score of each wearable identifier can be inversely proportional to the wearable identifier's periodicity. proportional to the frequency of UWB locations achieved with the wearable identifier. The use of such a priority score improves the selection of the priority identifier, and therefore ultimately allows for better regulation of locations with different wearable identifiers in case of overlap.

[0051] In some examples, for at least some of the wearable identifiers, the respective periodicity can be equal to the product of a respective multiplier (called a "RAN multiplier") and a predetermined minimum duration. For example, the wearable identifier can be configured to perform a location check at each successive time interval of duration T (where T is the wearable identifier's periodicity). In this case, the duration T can be equal to HRAN × Atmini, where HRAN is the respective multiplier of the identifier and Atmini is the predetermined minimum duration. The multiplier can be an integer. The predetermined minimum duration Atmini can be defined by a standard (e.g., 96 ms) and can be the same for all the wearable identifiers involved. In this case, the priority score of each wearable identifier can be proportional to this respective multiplier HRAN of the wearable 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 process includes the S40 deprogramming of any overlapping UWB locations other than the one with the priority portable identifier. In other words, the process 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 process 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 for UWB frames sent by the portable identifier involved in the UWB location. The portable identifier itself may not be aware of the cancellation of its programming.

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

[0054] In some 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 might initially be out of range of the vehicle, and the user wearing it might approach the vehicle. This new identifier can 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 programming to the UWB system. The process can then include receiving this programming for the new identifier (as with the other identifiers in step S10).In this case, the process may include repeating 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 other locations 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 involves 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. Specifically, localization initially involves 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 involves the UWB anchors listening for UWB 410 frames sent by portable identifier 400 during the first two time slots. After this initial phase, the anchors respond by sending their respective frames to the portable identifier, one after the other. Specifically, localization involves each UWB anchor successively sending a frame (frame 412 for 401, frame 413 for 402, and frame 414 for 403) to portable identifier 400 during a respective time slot. The portable identifier is configured to listen for and receive these frames 412, 413, and 414 sent by the anchors sequentially. The localization process then involves two transmissions, 415, by identifier 400, of a frame on the last two time slots to each of the UWB anchors 401, 402, 403 of the system. These two transmitted frames are listened to and received by portable identifier 400.

[0057] The duration of each UWB location "RR_time" 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 involves determining the distances between the portable identifier 400 and each of the system's UWB anchors 401, 402, and 403. 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 either the identifier or the anchor, and can be performed in any way. For example, each measurement could include recordings of the times the exchanged frames were sent and received, and the calculation could be performed by subtracting the time taken by each frame to travel to or from these recordings. Each measurement could then include a deduction of the distance between the identifier and the anchor from this time-of-flight.For example, each measurement might involve multiplying the speed of the signal carrying the UWB frame by the calculated time of flight. The signal speed could be a predetermined and known speed (e.g., stored in the identifier or system memory). Alternatively, the signal speed, i.e., the propagation speed of UWB waves, could be the speed of light (a constant stored in memory).

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

[0060] The deprogramming of such a location is now being 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 overlap, the session containing the first programmed location is executed, and the second session waits for the next period to attempt a location between the wearable identifier and the vehicle's anchors.

[0061] To cancel a location associated with an identifier, the system can, for example, stop listening to the frames sent by the portable identifier. For instance, the cancellation might include stopping listening to the first 410 frames sent by the identifier to each anchor. In some examples, the cancellation might also include stopping the transmission of frames 412, 413, and 414 successively transmitted by each anchor thereafter, and / or stopping 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 includes, for a set of successive periods (of approximately 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 location's position 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 The programmed UWB location can, for example, vary pseudo-randomly each period. Alternatively, the location position for each period can be fixed. For example, each UWB location can always be performed on the same time slot of each period (e.g., the first). Each 424-hour slot is itself divided into time intervals (called "slots"). The location can include UWB exchanges between the wearable identifier and the system on each of these time intervals.

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

[0065] The figure illustrates, in particular, the initial planned locations for each identifier over the first successive periods. For the first identifier, 431, the figure shows the first three locations, 435, 436, and 437, distributed across three successive periods, 432, 433, and 434. For this identifier, each period is divided into eight 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 location tracking is not performed in the same slots. Specifically, location tracking is performed in the first slot for the first period 442, but in the second slot for the second period 443, and in the third slot for the third period 444.

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

[0068] In this example, the first three identifiers, 431, 441, and 451, have periods of roughly the same duration. Their location frequency is therefore roughly the same. However, the fourth portable identifier, 461, has a longer period. It therefore has a higher priority score than the others. In case of overlap, the scheduling process 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 has the longest period.The process then includes an S40 deprogramming of each UWB location included in the overlay other than UWB location 463 with the 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] This process thus offers improved utilization of the vehicle's UWB system. Indeed, preserving location 463, which involves the portable identifier with the highest frequency 461, prevents an excessively long gap in location for identifier 463. Otherwise, it would have been particularly detrimental to identifier 461 not to preserve its location, given its low location frequency and the resulting long period without location information until its next location with the system. Furthermore, the other identifiers 431, 441, and 451 have shorter periodicities. They are more likely to be able to locate themselves more quickly than identifier 461 and are therefore less affected by this cancellation.They each still have two programmed locations over the time interval shown in the figure, and therefore still have two chances to perform a location with the system despite the cancellation of their first location. The. This process therefore allows for a better distribution of locations between the different identifiers, and allows for 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 various illustrated situations. In both situations, five wearable identifiers are simulated around the vehicle. The simulation is performed using a Python program to simulate, via a Monte Carlo method, simultaneous location sessions (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] Table 1

[0072] Figure 6 shows the results obtained without using the scheduling process in these two situations, and Figure 7 shows the results obtained when the scheduling process is used. The tables representing the different situations indicate, for each identifier involved, the longest duration without a location of the identifier (column "Max (ms)"), the percentage of times more than one second elapsed between two locations (column "> ls"), and the priority of the identifier (column "priority"). 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 identifiers with a long periodicity.For example, they are greater than 3% for the first three identifiers in the first situation 501, and greater than 1% in the second situation 503.

[0073] When the planning process is used, it assigns a priority score based on the periodicity. Specifically, in the first situation (511), the process assigns a score of 50 to the first three identifiers but 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 with a longer periodicity than to the last two. The results show that the planning process results in a percentage of less than 1% of the time between two locations where more than one second elapsed for all identifiers in these two situations. In particular, the probability of a waiting time exceeding one second is reduced sevenfold for identifiers with a longer periodicity.The planning process thus enables 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 process in a situation where two key fobs and three third-party devices (smartphones) are located around the vehicle. Specifically, the figure shows the change in the percentage of times more than one second elapsed between two locations (Y-axis) for each of these five identifiers. The figure also shows how this percentage changes as a function of the frequency of the first of the two key fobs (X-axis). The figure shows the change in 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 listed in Table 1.

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

[0076] The Tier A 703 device has the highest periodicity (288 ms), with a multiplier of 3. It therefore also has the highest priority score (40). The Tier B 704 device has a medium periodicity (192 ms) with a multiplier of 2. It therefore has a medium priority score (20). The Tier C 704 device has a short periodicity (96 ms) with a multiplier of 1. It therefore has a low priority score (20). In case of overlap, the Tier A device will have priority over the other two, and the Tier B device will have priority over the Tier C device. The figure shows that the process 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 (specifically 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 310 portable identifier. A 310 portable identifier could, for example, be a vehicle remote key fob. A vehicle remote key fob case may include a protective housing enclosing the key fob components. The protective housing may be made of plastic, metal, and / or a rubberized plastic material. The 310 key fob case 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 case 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 vehicle lock.

[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 locating 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's 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 from among the at least two portable identifiers, the priority identifier determined being the one with 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 portable identifier, an associated priority score, the determination (S30) of the priority identifier comprising a comparison of the priority scores of the portable 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 portable 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 portable 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 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: • the transmission, via the portable identifier, of UWB frames; and • listening, by the UWB system, to the UWB frames sent, the deprogramming (S40) of a UWB location including a cancellation of 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 stored.

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