Use of a vehicle UWB system

Abstract

The invention relates to a method for using a vehicle UWB system (700) comprising one or more UWB sensors (720) and having registered therein a set of UWB devices (301, 302, 303). The set of UWB devices (301, 302, 303) comprises a first UWB device (301) and a second UWB device (303). The method periodically comprises, for each UWB device, receiving (S10) a schedule of localisations by the one or more UWB sensors, including a first localisation and a second localisation. The method comprises verifying (S20) an execution reliability for the scheduling of the first localisation and the second localisation and, if the verification fails, modifying (S30) the schedule. The method improves the usability of the vehicle UWB system (700).

Description

Description Title of the invention: Use of vehicle UWB system Technical field

[0001] This disclosure relates to the use of a vehicle UWB (Ultra Wide Band) system. Technical background

[0002] Vehicles currently exist equipped with a UWB system comprising one or more UWB sensors installed in the vehicle. Such a UWB system generally registers a set of UWB devices, and is then capable of determining the position of each of the UWB devices from locations between each of the UWB devices and the UWB sensors of the system. For this, existing methods of using such UWB systems generally comprise, periodically, receiving a schedule of locations for each UWB device, these locations then being used to determine the position of each of the UWB devices.

[0003] Each location is generally scheduled over a time interval, and, during this time interval, the scheduled location comprises UWB emissions between one of the UWB devices and each of the UWB sensors. When two locations are scheduled such that they would overlap if executed, i.e., when the time intervals over which they are scheduled have a non-zero intersection, existing methods generally include canceling the scheduling of one of the two locations. Indeed, this reduces the risk of interference between the UWB emissions of the two locations. However, such cancellation reduces the number of locations finally executed for the UWB device of which one of the locations has been canceled. This has the consequence of reducing the accuracy and sensitivity of the location for this UWB device.

[0004] Therefore, there is a need for an improved vehicle UWB system. Summary

[0005] To this end, a method is proposed for using a vehicle UWB system comprising one or more UWB sensors and having registered a set of UWB devices. The set of UWB devices comprises a first UWB device and a second UWB device. The method comprises periodically, for each UWB device, receiving a programming of locations by the one or more UWB sensors, including a first location and a second location. The first location is a location of the first UWB device programmed over a first time interval. The second location is a location of the second UWB device programmed over a second time interval. The first time interval and the second time interval have a non-zero intersection for at least one period.The method periodically comprises, for each of the at least one period, a verification of the reliability of execution of the programming of the first location and of the second location, and, when the verification fails, a modification of the programming.

[0006] Each location can include UWB emission exchanges. Verification can comprising a determination of the time distances between the UWB emissions of the first location and the UWB emissions of the second location, and, a verification that each of the determined time distances is at least greater than a predetermined time distance value.

[0007] Changing the programming when verification fails may include determining a priority UWB device among the first UWB device and the second UWB device, and programming the location of the priority UWB device.

[0008] The predetermined time distance value can be greater than 250 microseconds and / or less than 1 millisecond.

[0009] Programming of locations can be done for a duration of less than 10 seconds.

[0010] The method may include detecting a new UWB device, and repeating the reception of the programming and verification for the new UWB device.

[0011] The method may include, after the verification, performing the locations according to the received schedule when the verification succeeds or according to the modified schedule when the verification fails, and determining the position of each of the UWB devices from the performed locations.

[0012] A vehicle UWB system is also provided. The UWB system comprises one or more UWB sensors. The system is configured to be used according to the method.

[0013] A UWB sensor is also provided for such a vehicle UWB system. The UWB sensor is configured for use in the system according to the method.

[0014] A computer program is also provided. The computer program comprises program code instructions for executing the method, when said program is executed by a processor. Brief description of the figures

[0015] Non-limiting examples will be described with reference to the following figures:

[0016] [Fig. 1] shows a flowchart of an example of the process.

[0017] [Fig. 2] shows an example of programming multiple locations.

[0018] [Fig. 3] shows an example of a localization performed within a time interval consisting of a series of time slots.

[0019] [Fig. 4] shows a first example of implementation of the method.

[0020] [Fig. 5] and [Fig. 6] show a second example of implementation of the method.

[0021] [Fig. 7] shows an example of vehicle use from the programmed locations according to the method.

[0022] [Fig. 8] shows an example of localizing a UWB device with one or more UWB sensors.

[0023] [Fig. 9] shows an example of determining the number of time slots in each series for a UWB device.

[0024] [Fig. 10] shows an example of a vehicle UWB system. Detailed description

[0025] A method of using a vehicle UWB system comprising one or more UWB sensors and having registered a set of UWB devices is provided. The set of UWB devices comprises a first UWB device and a second UWB device. The method comprises periodically, for each UWB device, receiving a schedule of locations by the one or more UWB sensors, including a first location and a second location. The first location is a location of the first UWB device, and the first location is scheduled over a first time interval. The second location is a location of the second UWB device, and the second location is scheduled over a second time interval. For at least one period, the first time interval and the second time interval have a non-zero intersection.The method comprises, for each of the at least one period (i.e. for each period during which the time interval of the first location has a non-zero intersection with the time interval of the second location), a verification of a reliability of execution of the programming of the first location and of the second location, and, when the verification fails, a modification of the programming.

[0026] The method provides improved usability to the vehicle UWB system.

[0027] Indeed, the verification of the execution reliability makes it possible to evaluate in advance whether the first location and the second location can be executed correctly according to their programming, and the method comprises a modification of the programming when this verification fails (i.e. when the method anticipates an execution unreliability at the end of the verification). This verification is particularly relevant since the first location and the second location are programmed on time intervals having a non-zero intersection over at least one period. The method therefore makes it possible to react to the detection of a future lack of reliability, and thus to reduce the risk of interference between the first location and the second location for each period during which, otherwise, these two locations would overlap during their execution.

[0028] Furthermore, the verification makes it possible to avoid the direct but suboptimal solution of systematically canceling the programming of one or two of the first or second locations when their time intervals have a non-zero intersection. Indeed, the method makes it possible to potentially keep the programming of these two locations when they allow it, and to modify the programming only when the verification fails. In particular, the cancellation of a location reduces the number of locations programmed for the UWB device involved in the canceled location, which has the consequence of reducing the accuracy and sensitivity of the location. The method therefore makes it possible to increase overall and over time the accuracy and sensitivity of location of the UWB devices.

[0029] The method may include, after verification, executing the locations. When the verification succeeds, the method may include executing the locations according to the initially received schedule. When the verification fails, the method may include executing the locations according to the modified schedule. For example, the method may include executing the locations except for the one that was canceled.

[0030] After executing the localizations, the method may comprise determining the position of each of the UWB devices from the executed localizations. For example, each localization of a UWB device may comprise providing a relative position of the UWB device with respect to the UWB system. For example, the localization may comprise, for each UWB sensor, a respective distance measurement between the UWB device and the UWB sensor, and determining the relative position of the UWB device with respect to the UWB system from the respective distance measurements between the UWB device and each of the UWB sensors. The determined position may vary over time. For example, each localization may provide a position of a UWB device with respect to the UWB system at a given time, and all of the localizations involving this executed UWB device may provide an evolution of the position of this UWB device over time.

[0031] After performing the localizations, the method may include one or more uses of the determined relative positions of the UWB devices. For example, the method may include activating one or more features of the vehicle based on the relative positions of the first and second UWB devices. For example, the feature may include locking the vehicle when it is determined that the first and second UWB devices are outside the vehicle, for example after a predetermined time has elapsed between the time when it is determined that each of the first and second UWB devices is outside. In examples, the feature may include selectively unlocking one or more openings of the vehicle (e.g., a driver's door, a passenger door, or a trunk of the vehicle) based on the determined relative positions of the UWB devices.For example, the functionality may include unlocking the driver's door and the trunk of the vehicle when the position of one of the UWB devices approaches the driver's door (e.g., the first UWB device) and the position of another of the UWB devices (e.g., the second UWB device) approaches the trunk (i.e., when two users wearing these devices approach these openings, for example, at the same time or one after the other). In other examples, the functionality may include unlocking the driver's door and / or the passenger doors (e.g., when one or more users approach these openings), and, for each user, making one or more adjustments (e.g., adjustment of headrest height or seat position) based on an access zone of the user (e.g., based on the opening to which the user has approached).In still other examples, the functionality may include activating one or more vehicle functions such as playing music or adjusting the mirrors appropriate for the person wearing the UWB device that is positioned at the driver's seat (the first UWB device when the person wearing the first UWB device is driving and the second UWB device when the person wearing the second UWB device is driving). The method may include any combination of these example functionality.

[0032] The method comprises, for each UWB device, receiving a programming of locations by the one or more UWB sensors. The programming may comprise a programming of one or more respective locations for each UWB device. The programming received may be digital data. The programming may comprise, for each UWB device, and for each location involving the UWB device, digital data defining a temporal positioning of the location, for example on a timeline. The timeline may represent a duration to come and which has not yet elapsed at the time of reception of the programming. The digital data defining the location may comprise data designating a start time of the time interval over which the location is programmed and data designating an end time of this time interval. Alternatively or additionally, the digital data defining each location may comprise digital data defining each of the UWB emissions of the location.For example, the digital data may designate a start time and an end time of each UWB emission of the location.

[0033] The received schedule may have been calculated for each period, for example by the UWB system. For example, the method may include, before each period, calculating a schedule for each location and recording the schedule, for example on a memory of the system. For example, for each UWB device in the set, the number of locations programmed per period may depend on the UWB device. For example, the method may include, before the first schedule reception, an exchange with the UWB device to determine the number of locations to be programmed per period. The exchange may include sending, from the UWB device to the UWB system, frequency information for the UWB device and calculating, by the UWB system, the number of locations to be programmed per period based on the frequency information. The frequency information may be a frequency or a duration that is specific to the UWB device.After this calculation, the reception of the programming may include a reading of the programming, on the system memory.

[0034] In the received schedule, the one or more respective localizations of the same UWB device may be programmed to be temporally separated. This means that at any given time, only one localization of the same UWB device is programmed to be executed. For example, the one or more respective localizations of the same UWB device may be programmed to be executed successively, one after the other. Each localization may be programmed to be executed over a respective time interval, i.e., the UWB transmissions of the localization may be carried out within the respective time interval. Each UWB transmission of the localization may begin at the same time or after a start time of the respective time interval and end before or at the same time as an end time of the respective time interval.UWB emissions from the same location may be temporally separated over the respective time interval. The respective time intervals of the one or more respective locations of the same UWB device may be temporally distinct. Two successive time intervals may follow one another directly (i.e., the end of a location may correspond to the beginning of. the next location), or may be spaced by a given duration.

[0035] The respective time intervals of the respective locations of the first UWB device and the second UWB device are not temporally distinct. The first location of the first UWB device is scheduled on a first time interval that overlaps the second time interval of the second location of the second UWB device. The first time interval and the second time interval have a non-zero intersection. For example, each of the first and second time intervals may include a respective start time and a respective end time, and the respective start time of the first time interval may be before the respective start time of the second time interval and the respective end time of the first time interval may be after the respective start time of the second time interval.Alternatively, the respective start time of the first time interval may be after the respective start time of the second time interval and the respective end time of the second time interval may be after the respective start time of the first time interval. Alternatively again, the respective start times of the first and second time intervals may be the same and / or the respective end times of the first and second time intervals may be the same.

[0036] "Periodically" means that, for a given duration of time, the method comprises receiving a programming of locations for each UWB device and, when the time intervals of two locations of the received programming have a non-zero intersection, verifying the programming, and that the method repeats at regular intervals of this given duration of time the reception of the programming for each UWB device and, in the case of a non-zero intersection, the verification of the programming. The period represents the duration of this given interval of time during which the reception of the programming for each UWB device and, in the case of a non-zero intersection, the verification of the programming are carried out.

[0037] For each of the at least one period, the method comprises a verification of the reliability of execution of the programming of the first location and the second location. For the other periods, the method may not execute the verification of the reliability of execution. For example, at the beginning of each period (or before a group of periods and for each period of the group), the method may comprise a non-intersection test of the time intervals of the programmed locations to determine whether the intersection of the time intervals of at least two locations is non-zero. When this test fails, i.e. when at least two locations are programmed on time intervals having a non-zero intersection, the method may comprise an execution of the verification of the reliability of execution of the programming of these at least two locations.When this test passes, the process may not perform the runtime reliability check, and directly wait or move on to the next period. Alternatively, the process may perform the check every period, in which case the process may not include the test.

[0038] The term “UWB device” (or “identifier”) refers to a mobile object identifiable by the vehicle, and for example whose location authorizes or not one or more (specific) actions of the vehicle. For example, the UWB device can be used to open the vehicle and / or turn on the vehicle's engine. For example, the method can comprise opening the vehicle when the UWB device is located near the vehicle, or turning on the engine when the UWB device is in the vehicle. The method can involve as UWB device(s) one or more key(s) and / or one or more smart devices (also called smart devices), such as a mobile phone.

[0039] The programming of locations can be done over a duration, for example, equal to a period, or to several times the period. The programming can include a determination, for each location, of a respective time interval over this duration over which the location is carried out. The programming of locations can be done for a duration of less than 10 seconds. The programming of locations can be done for a duration of more than 1 second.

[0040] The duration over which the programming is carried out may correspond to a time that has not yet elapsed, that is to say a duration to come in relation to the instant of programming and execution of the process. The length of the duration may be fixed or vary, for example depending on the vehicle's environment.

[0041] Each UWB transmission may comprise a sending of a frame by the UWB device to the one or more UWB sensors or a sending of a frame by one of the one or more UWB sensors to the UWB device. UWB may refer to a communication protocol, for example that specified by F IEEE 802.15.4. The programming of the one or more locations may comprise, for each location, a determination of a time position for each of the frame sendings. A frame sending may have a duration of between 60 and 137 microseconds. The determination of a time position for a frame sending may comprise a determination of a time for the start of sending and the end of sending of the frame. The time between the start and the end may be equal to a sending duration. The sending duration may be a function of a length of the frame and a sending rate.The positioning of the start and end can be a function of the frame length and / or the sending rate.

[0042] For each location, the respective time interval over which the location is scheduled may consist of a series of time slots. The time slots in the series may have substantially equal duration. Each slot may have a duration, for example, greater than or equal to 1 millisecond and / or less than or equal to 8 milliseconds. The duration of the slot may be a function of the UWB device involved in the location.

[0043] The scheduling may include, for each UWB device, scheduling the locations over a respective session corresponding to a period. A session may have a duration that corresponds to a multiple of a predetermined time, for example, once, twice, three times, or ten times 96 milliseconds. Parenthetical references are provided below with reference to Figure 3. Each session (201) may be divided into blocks (202, 203, 204). Each block may be divided into multiple intervals of time (205, 206, 207), and a location can be performed within one of these time intervals. Each of the time intervals can be divided into a series of time slots (210, 211, 212, 215, 216). The UWB transmissions of each location can be performed within time slots of a series of the UWB device session. For each session, the blocks, the time intervals of each block, and the time slots can be numbered, and the received schedule can include, for each location of the session during the period, digital data defining, for each block, the number of the time interval on which the location is scheduled. The received schedule can also include, for each location of the session during the period, the number of the time slot of the time interval on which each UWB transmission of the location is scheduled.Calculating the schedule for each UWB device may include determining the number of time slots in each series, the number of time intervals in each block, and / or the number of blocks per session for each UWB device.

[0044] By "verification of a reliability of execution of the programming of the first location and the second location", we mean the evaluation of a reliability criterion of the results that would be obtained by the first location and the second location if they were executed according to a given programming, in this case the programming that is initially received in the method. The reliability criterion may in particular correspond to the potential presence of interference between the UWB emissions linked to the first location and the UWB emissions linked to the second location. The verification "fails" when the UWB emissions are such that interference is expected, and on the contrary the verification "succeeds" when interference is not expected, at least not between the first location and the second location precisely.

[0045] The execution reliability verification makes it possible to evaluate in advance whether the first location and the second location can be executed correctly according to their programming. Indeed, the verification “fails” when the UWB emissions linked to the first location and the second location are such that interference is expected. In this case, the method anticipates an execution unreliability at the end of the verification, and the method comprises a modification of the programming. The method therefore makes it possible to react to the detection of a future lack of reliability, and thus to reduce the risk of interference between the first location and the second location for each period during which, otherwise, these two locations would overlap during their execution.

[0046] The verification makes it possible in particular to avoid the direct but suboptimal solution consisting of systematically canceling the programming of one or two of the first or second locations when their time intervals have a non-zero intersection. The method makes it possible to potentially keep the programming of these two locations when interference is not expected, and to modify the programming only when interference is expected. Since cancellation has the consequence of reducing the accuracy and sensitivity of the location, the method therefore makes it possible to increase overall and over time the accuracy and sensitivity of the location of UWB devices.

[0047] Verification of execution reliability may consist of verifying that a time distance between the UWB emissions of the first location and the UWB emissions of the second location is at least greater than a predetermined time distance value. The verification may thus comprise a determination of the time distances (503, 505, 507 in FIG. 6) between the UWB emissions of the first location and the UWB emissions of the second location (for example, with the exception of those between two successive UWB emissions from the same location). For example, each UWB emission may be planned over a respective time interval, and the time intervals of the UWB emissions of the first location and the second location may follow one after the other. The time distance may be the time distance between the respective time intervals of the successive UWB emissions.The verification may then comprise, for each UWB transmission, a determination of the time distance with a previous UWB transmission and with a following UWB transmission. For each UWB transmission, the time distance may correspond to a time elapsed between the end of frame sending of the previous UWB transmission and the start of frame sending of the UWB transmission, or a time elapsed between the end of frame sending of the UWB transmission and the start of frame sending of the following UWB transmission. When the time distance between each of the respective time intervals of the locations is greater than the predetermined time distance value, the verification may succeed, and, conversely, when at least one time distance between two respective time intervals of two locations is less than the predetermined time distance value, the verification may fail.Alternatively, two time intervals of two UWB emissions may not follow each other, i.e., the respective time interval of a first of the UWB emissions may have a non-zero intersection with the respective time interval of a second of the UWB emissions. In this case, the time distance between these two UWB emissions may be zero, and the verification may fail.

[0048] After determining the time distances, the verification may include verifying that each of the determined time distances (e.g., except for those between UWB emissions from the same location) is at least greater than a predetermined time distance value. The verification may include comparing each of the determined time distances with the predetermined time distance value; the predetermined time distance value may be greater than or equal to 250 microseconds, for example, strictly greater than 250 microseconds. The predetermined time distance value may be less than or equal to 1 millisecond, for example, strictly less than 1 millisecond.

[0049] When the execution reliability check is successful, the method may include executing the locations according to the received, i.e., initial, schedule. The method may not modify the schedule of the first and second locations. The method may retain the schedule of the first and second locations.

[0050] When the verification fails, the method includes modifying the schedule. The modifying the schedule may include canceling one of the first and second locations.

[0051] For example, modifying the schedule may include, when the verification fails, randomly canceling one of the first and second locations. Modifying the schedule may include randomly selecting one of the first and second locations, and canceling the schedule of the randomly selected location. The method may then include executing the locations according to the modified schedule, i.e., executing the locations except for the randomly selected location.

[0052] Alternatively, the modification of the scheduling may, when the verification fails, be based on a priority order between the UWB devices. The modification of the scheduling may include a determination of a priority UWB device among the first UWB device and the second UWB device, and, a scheduling of the location of only the priority UWB device. For example, the UWB devices in the set may be prioritized by the UWB system. Each UWB device may include a priority ranking relative to the other UWB device(s) in the set. The determination of a priority UWB device may include a comparison of the rankings of the first UWB device and the second UWB device. The determination may include a determination of which UWB device among the first UWB device and the second UWB device having the highest ranking may be determined to have priority.Alternatively, one of the UWB devices in the set may be a priority UWB device, i.e., it may be designated as such in the UWB system. In this case, when the first UWB device or the second UWB device is the priority UWB device, the method determines it as such (the other being a secondary UWB device relative to the one that is prioritized).

[0053] Then, the method may include programming the location of only the priority UWB device. The method may include canceling the programming of the location of the other UWB device, i.e., the UWB device among the first UWB device and the second UWB device that is not determined to be a priority. The programming of the locations of the priority UWB device is unchanged, and that of the UWB device that is not determined to be a priority includes one location less. The method may then include executing the scheduled locations, including executing all the locations initially scheduled for the priority UWB device and the locations of the UWB device that is not determined to be a priority initially scheduled except for the one whose programming was canceled.

[0054] In examples, the locations may include a third location that is a location of a third UWB device scheduled over a third time slot. The third time slot may have a non-zero intersection with the first time slot and / or the second time slot. In this case, the method may include verifying the scheduling of the first location, the second location, and the third location (wherein the time distances are determined between each of the UWB emissions of the first location, the second location, and the third location). location and the third location). When the verification fails, the method may comprise determining a priority UWB device from among the first UWB device, the second UWB device and the third UWB device, and programming the location of the priority UWB device, i.e. canceling the other locations from among the first location, the second location and the third location which are not locations of the priority UWB device. The method may similarly verify the programming of a number N of overlapping locations, and only program the location of the UWB device determined as priority when this verification fails.

[0055] The UWB system may have registered one or more other UWB devices than the UWB devices in the set that are involved in the method. The method may detect that the one or more other UWB devices are not within range of the vehicle, and therefore decide not to involve them in using the method.

[0056] In examples, the method may include detecting a new UWB device. For example, the new UWB device may be one of one or more other UWB devices that are registered in the UWB system. The new UWB device may be, for example, a UWB device that was not in range of the vehicle at the start of the method, and has just entered the vehicle's range (and is therefore detected by the UWB system). The method may include repeating the receiving of the programming and the verification for the new UWB device.

[0057] A UWB sensor for a vehicle UWB system is also provided. The UWB sensor is configured for use of the system according to the use method and / or for carrying out the planning method.

[0058] The UWB sensor may be configured to perform both localization and radar measurements, and / or to be programmed for this purpose. The UWB sensor may be configured to receive one or more commands (for example received from the UWB system) to send a frame of a UWB exchange and / or to transmit a frame of a radar measurement. The UWB sensor may be configured to, after transmitting a frame of a radar measurement, change configuration before sending a frame of a UWB exchange or to, after sending a frame of a UWB exchange, transmit a frame of a radar measurement. The UWB sensor may be configured to make this change, for example, in less than a millisecond.

[0059] A vehicle UWB system is also provided. The UWB system includes one or more UWB sensors. The system is configured for use according to the method. The UWB system may be configured to, after execution of the method, send one or more commands to each UWB sensor according to the initial programming when the verification succeeds or the modified programming when the verification fails. The one or more commands may include requests to send frames of UWB transmissions of the locations according to the initial programming when the verification succeeds or according to the modified programming when the verification fails.

[0060] A UWB sensor is also provided for such a vehicle UWB system. The UWB sensor is configured for use of the system according to the method. The UWB sensor is configured to receive the one or more orders sent by the UWB system, and execute the sending of frames of the UWB emissions of the locations according to the orders sent, that is to say according to the initial programming when the verification succeeds or according to the modified programming when the verification fails.

[0061] A computer program is also provided. The computer program comprises program code instructions for executing the method, when said program is executed by a processor. The computer program may be stored in a memory. The UWB system may comprise the processor and / or the memory.

[0062] Examples will now be given with reference to Figures 1 to 10.

[0063] [Fig. 1] shows a flowchart of an example of the method. The method is a method of operating a vehicle UWB system comprising one or more UWB sensors and having registered a set of UWB devices. The set of UWB devices comprises a first UWB device and a second UWB device. The method comprises periodically, for each UWB device, receiving S 10 a scheduling of locations by the one or more UWB sensors, including a first location and a second location. The first location is a location of the first UWB device, and the first location is scheduled over a first time interval. The second location is a location of the second UWB device, and the second location is scheduled over a second time interval. For at least one period, the first time interval and the second time interval have a non-zero intersection.The method comprises, for each of the at least one period, a verification S20 of the reliability of execution of the programming of the first location and of the second location, and, when the verification fails, a modification S30 of the programming.

[0064] The verification S20 comprises a determination S21 of the time distances between the UWB emissions of the first location and the UWB emissions of the second location, and, a verification S22 that each of the determined time distances is at least greater than a predetermined time distance value. The modification S30 of the programming when the verification comprises a determination S31 of a priority UWB device among the first UWB device and the second UWB device, and, a programming S32 of the location of the priority UWB device.

[0065] The method comprises, after the verification S20, an execution of the locations according to the received programming when the verification succeeds S40 or according to the modified programming when the verification fails S30, and, a determination S50 of the position of each of the UWB devices from the executed locations.

[0066] [Fig. 2] shows an example of the programming of locations. Figure 2 shows, for each UWB device 101, 102, 103, a respective block 111, 112, 113. Each block can last for example 288 milliseconds. Each respective block 111, 112, 113 comprises eighteen time intervals 104. Each time interval can last for example 16 milliseconds. For each UWB device, the method of use comprises a location 121, 122, 123 of the UWB device with the one or more UWB sensors. The location 121 involves the UWB device 101, the location 122 the UWB device 102 and the location 123 the UWB device 103. Each location includes an RF (acronym for Radio Frequency) active part. The RF active part corresponds to the portion of the time interval over which the location includes UWB emissions. In the figure, the FT active part 131 corresponds to the location involving the UWB device 101, the FT active part 132 corresponds to the location involving the UWB device 102 and the FT active part 133 corresponds to the location involving the UWB device 103. The figure also shows other FT active parts 134 corresponds to the location involving other UWB devices not shown.

[0067] [Fig. 3] shows an example of a localization performed within a time interval consisting of a series of time slots. The figure shows a session 201 of a UWB device. The session may comprise, for example, three blocks 202, 203, 204, each comprising, for example, six time slots. The method of use comprises a respective localization for each of the three blocks. For each block, the localization is performed within one of the six time slots of the block (time slot 205 for block 202, time slot 206 for block 203, and time slot 207 for block 204).

[0068] The localization performed within the interval 205 (which is equivalent to 401 in Figure 8) is now discussed in more detail. The other localizations can be performed in the same way. The time interval 205 consists of a series of time slots 210, 211, 212, 213, 214, 215, 216, 217. The UWB device involved in the localization can be a priority UWB device or a secondary UWB device. The localization performed within the interval 205 comprises UWB transmissions between the UWB device and the one or more UWB sensors. Each UWB transmission comprises the sending of a frame between the UWB device and the one or more UWB sensors. The sending of frames of the UWB emissions between the UWB device and the one or more UWB sensors is carried out within slots of the series (time slots 210, 211, 212, 214, 215 and 216).The sending of frame 220 is carried out on slot 210, the sending of frame 221 on slot 211 and the sending of frame 222 on slot 212. Frames 220 and. 221 are sent from the UWB device to each of the one or more UWB sensors. On time slots 212, 213 and 214, each of the one or more UWB sensors sends a respective frame to the UWB device (e.g. tram 222 on slot 212). Then, sending of frame 225 is performed on slot 215 and sending of frame 226 on slot 216. Frames 225 and 226 are sent from the UWB device to each of the one or more UWB sensors. Frames 220, 221, 222, 225 and 226 are sent at the beginning of time slots 210, 211, 212, 215 and 216.

[0069] [Fig. 4] shows a first example of implementation of the method. The UWB system has recorded a set comprising a first UWB device 301, a second UWB device 302 and a third UWB device 303. The method comprises periodically, for each UWB sensor, a reception S 10 of a location schedule by the one or more UWB sensors. The received location schedule comprises, for each UWB device, a location for each of the blocks of the period, and, for each location, the time interval 312 of the block on which the location is planned. For example, for the first block 311 of the session of the first UWB device 301, the programming includes digital data indicating that the location is planned for the first time interval 313 of the block 311.

[0070] The locations of the received schedule for this period include a first location 314 and a second location 334 that overlap. The first location 314 is a location of the first UWB device 301 scheduled on a first time slot, and the second location 334 is a location of the third UWB device 303 scheduled on a second time slot. The first time slot and the second time slot have a non-zero intersection.

[0071] The method comprises verifying S20 the reliability of execution of the programming of the first location and the second location. The verification comprises determining the time distances between the UWB emissions of the first location and the UWB emissions of the second location, and verifying that each of the determined time distances is at least greater than a predetermined time distance value. In this first example, the verification fails. Each of the determined time distances is therefore not at least greater than the predetermined time distance value. For example, two UWB emissions overlap, or are not spaced apart by a time distance greater than or equal to the predetermined time distance value. The method then comprises modifying the programming.The modification of the programming comprises, in this example, a cancellation S334 of the second location 334 initially programmed for the third UWB device 303 (the first UWB device 301 having, for example, priority over the third UWB device 303).

[0072] The locations of the received schedule for this period include a third location 315, a fourth location 325, and a fifth location 335 that overlap. The third location 315 is a location of the first UWB device 301 scheduled on a third time slot, the fourth location 325 is a location of the second UWB device 302 scheduled on a fourth time slot, and the fifth location 335 is a location of the third UWB device 303 scheduled on a fifth time slot. The third time slot has a non-zero intersection with the fourth time slot and with the fifth time slot.

[0073] The method therefore comprises a verification S20' of the reliability of execution of the programming of the third location 315, the fourth location 325 and the fifth location 335. The verification comprises the determination of the time distances between the UWB emissions of the third location 315, the fourth location 325 and the fifth location 335, and, the verification that each of the determined time distances is at least greater than a predetermined time distance value. In this first example, the verification fails, and each of the determined time distances is therefore not at least greater than the predetermined time distance value. For example, the time distances between the UWB emissions of the third location- tion 315 and the fourth location 325, and, the time distances between the UWB emissions of the third location 315 and the fifth location 335, are not all greater than the predetermined time distance value.

[0074] The method then comprises a modification of the programming. The modification of the programming comprises, in this example, a cancellation S325 of the fourth location 325 initially programmed for the second UWB device 302 and a cancellation S335 of the fifth location 335 initially programmed for the third UWB device 303 (the first UWB device 3014 having, for example, priority over the second UWB device 302 and over the third UWB device 303).

[0075] [Fig. 5] and [Fig. 6] show a second example of the implementation of the method. In this example, verification S20 of the reliability of the execution of the programming of the first location and the second location succeeds. Figure 5 shows the UWB emissions 411, 412, 413, 414 and 415 from the first location 314 and the UWB emissions 431, 432, 433, 434 and 435 from the second location 334. Figure 6 shows the time distances 501, 502, 503, 504, 505, 506, 507, 508, 509 between the UWB emissions 411, 412, 413, 414 and 415 from the first location 314 and the UWB emissions 431, 432, 433, 434 and 435 from the second location 334.The determination comprises a projection S510, on the same time line, of the UWB emissions 411, 412, 413, 414 of the first location 314 and of the UWB emissions 431, 432, 433, 434 and 435 of the second location 334, and, following the time line, a determination of the temporal distances 501, 502, 503, 504, 505, 506, 507, 508, 509 between each of the successive projected emissions. The verification comprises a determination of the temporal distances between the UWB emissions of the first location and the UWB emissions of the second location (i.e. with the exception of those between two UWB emissions of the same location). For example, the verification includes a determination of the time distance 503 between the two successive UWB emissions 413 and 431, then of the time distance 505 between 432 and 414, then of the time distance 507 between 415 and 433.

[0076] Verification S20 then comprises verifying that each of the determined time distances 503, 505 and 507 is at least greater than the predetermined time distance value. For example, the method may successively verify that each of the determined time distances 503, 505 and 507 is at least greater than the predetermined time distance value. Alternatively, the method may verify in parallel that each of the determined time distances 503, 505 and 507 is at least greater than the predetermined time distance value.

[0077] In this example, the method determines the time distances successively by following the timeline, and then verifies that each of these time distances is at least greater than the predetermined time distance value. In other examples, the method may determine the set of time distances in another way, for example by determining the time distances separating all the UWB emissions from each other, and verifying that all of these time distances are indeed greater than the predetermined time distance value.

[0078] In this second example, the verification succeeds. Each of the determined time distances 503, 505 and 507 is therefore at least greater than the predetermined time distance value. The method then comprises an execution S20 of the first location 314 and the second location 334 according to the initially received programming.

[0079] In this second implementation example also, the time distances between the UWB transmissions of the third location 315 and the fourth location 325 are all greater than the predetermined time distance value. Only the time distances between the UWB transmissions of the third location 315 and the fifth location 335 are not all greater than the predetermined time distance value. Thus, the verification S20' of the execution reliability of the programming of the third location 315 and the fourth location 325 succeeds and the verification S20' of the execution reliability of the programming of the third location 315 and the fifth location 335 fails.

[0080] The method therefore comprises a modification of the programming, and this modification comprises, in this second example, a cancellation S335 of the fifth location 335 initially programmed for the third UWB device 303 only. The modification of the programming does not comprise a cancellation of the fourth location 325 since the third 315 and fourth 325 locations can be executed together without risk of interference between the UWB emissions.

[0081] [Fig. 7] shows an example of vehicle use from the programmed locations according to the method.

[0082] During the driving / running of the vehicle engine, F use comprises a localization S 10 in the cabin of a UWB device carried by the driver (the "identifier"). After a detection of a stable position S20 of the identifier in the cabin (for example after several localizations in the same position of the identifier), the use comprises a re-evaluation SU of the location in the cabin of the identifier. Then, the use comprises a change S21 of the position of the identifier in the cabin and then a new localization S 10 of the identifier in the cabin. After stopping the engine, the use again comprises a stable position S20 of the identifier in the cabin, a re-evaluation SU of the location in the cabin of the identifier, then a change S21 of the position of the identifier in the cabin followed by a new localization S 10 of the identifier in the cabin.The use also includes an external location S 15 of all identifiers after the identifier is located S22 outside. At the time of a closure, the use may include one or more radar measurements to check for the absence of occupants who may have remained in the vehicle after closure.

[0083] [Fig. 8] shows an example of localization of a UWB device with the one or more UWB sensors. The localization comprises two sendings 410 of a frame on two first time slots from the UWB device 400 to each of the UWB sensors 401 (which is equivalent to 205 in FIG. 3), 402, 403. The localization then comprises, successively and on a respective time slot, a sending of a frame by each of the UWB sensors (the frame 412 for the 401, the frame 413 for the 402 and the frame 414 for the 403). The localization then comprises two sendings 415 of a frame on last two time slots from the UWB device 400 to each of the UWB sensors 401, 402, 403.

[0084] [Fig. 9] shows an example of determining the number of time slots in each series for a UWB device. The determination may be based on the application of a standard, for example using table 900. The determination includes determining a time slot duration 901 for the UWB device. For example, the UWB device may communicate its duration to the UWB system. Table 900 includes a series of numbers 902 each adapted for the UWB system. The determination includes determining a number of time slots per time interval from the series 902. The number of time slots corresponds to the number in the predetermined series that is closest to and greater than or equal to the sum of the number of UWB sensors in the system and a constant (e.g., 4). Table 900 also includes the number of time slots per block as a function of the time slot duration and the number of time slots per series.For example, in this table 900, for a time slot duration of 1 millisecond and 12 time slots per series, the number of time intervals per block is 8. The determination may include determining a number of time intervals per block based on the time slot duration and the number of time slots per time interval.

[0085] [Fig. 10] shows an example of a vehicle UWB system 700. The UWB system 700 comprises a central unit 710 and several UWB sensors 720 positioned at the front of the vehicle, at the rear of the vehicle or in the cabin of the vehicle. The UWB system 700 also comprises connection means between each of the UWB sensors 720 and the central unit 710. The figure also shows a UWB device 730, which is registered on the UWB system 700. A location comprises UWB exchanges 740 between the UWB device 730 and each of the UWB sensors 720.

Claims

Claims

1. A method of operating a vehicle UWB system (700) comprising one or more UWB sensors (720) and having registered a set of UWB devices (301, 302, 303), the set of UWB devices (301, 302, 303) comprising a first UWB device (301) and a second UWB device (303), the method periodically comprising: • for each UWB device, a reception (S 10) of a programming of locations by the one or more UWB sensors, including a first location (314) and a second location (334), the first location (314) being a location of the first UWB device (301) programmed over a first time interval, and the second location (334) being a location of the second UWB device (303) programmed over a second time interval, the first time interval and the second time interval having a non-zero intersection for at least one period; and • for each of the at least one period, a verification (S20) of the reliability of execution of the programming of the first location (314) and of the second location (334), and, when the verification fails, a modification (S30) of the programming.

2. The method of claim 1, wherein each location comprises UWB emissions, the verification comprising: • a determination (S21) of the temporal distances (503, 505, 507) between the UWB emissions (411, 412, 413, 414, 415) of the first location (314) and the UWB emissions (431, 432, 433, 434, 435) of the second location (334), and • a verification (S22) that each of the determined time distances (503, 505, 507) is at least greater than a predetermined time distance value.

3. The method of claim 1 or 2, wherein modifying (S30) the programming when verifying comprises: • a determination (S31) of a priority UWB device (301) among the first UWB device (301) and the second UWB device (303); and • programming (S32) of the location of the priority UWB device (301).

4. A method according to any one of claims 1 to 3, wherein the predetermined time distance value is greater than 250 microseconds and / or less than 1 millisecond.

5. Method according to any one of claims 1 to 4, in which the programming of the locations is done for a duration of less than 10 seconds.

6. A method according to any one of claims 1 to 5, wherein the method comprises: • detection of a new UWB device; and • a repeat of the programming reception and verification for the new UWB device.

7. A method according to any one of claims 1 to 6, the method comprising, after verification: • an execution of the locations according to the received programming when the verification succeeds (S40) or according to the modified programming when the verification fails (S30), and • a determination (S50) of the position of each of the UWB devices from the locations performed.

8. A vehicle UWB system (700) comprising one or more UWB sensors (720) and configured for use according to the method of any one of claims 1 to 7.

9. A UWB sensor (720) for a vehicle UWB system (700) and configured for use of the system according to the method of any one of claims 1 to 7.

10. A computer program comprising program code instructions for executing the method of any one of claims 1 to 7, when said program is executed by a processor.

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