Method for using a UWB system of a vehicle

Abstract

The invention relates to a method for using a UWB system of a vehicle comprising one or more UWB sensors and one or more registered identifiers. The method periodically comprises one or more locations. The one or more locations include, for each respective identifier, at least one respective location of the respective identifier with the one or more UWB sensors. The one or more locations are temporally separated from one another. The method periodically comprises a plurality of radar measurements. The plurality of radar measurements includes, for at least one respective UWB sensor, multiple respective radar measurements. The number of respective radar measurements is, for each identifier, greater than the number of at least one respective location(s) of the identifier with the one or more UWB sensors. The method enhances the use of a UWB system for a vehicle.

Description

Use of vehicle UWB system

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

[0002] Today, there are vehicles equipped with a UWB system that includes one or more UWB sensors installed in the vehicle. The UWB system records one or more identifiers, and the UWB system is then able to locate the one or more identifiers with the one or more UWB sensors. However, the use of the UWB system is generally limited to this location functionality.

[0003] Therefore, there is a need for an improved vehicle UWB system. Summary

[0004] For this purpose, a method is proposed for using a vehicle UWB system comprising one or more UWB sensors and having recorded one or more identifiers. This method is referred to in the following as "method of use", or simply "method". The method periodically comprises one or more locations. The one or more locations include, for each respective identifier, at least one respective location of the respective identifier with the one or more UWB sensors. The one or more locations are temporally separated. The method periodically comprises a plurality of radar measurements. The plurality of radar measurements includes, for at least one respective UWB sensor, several respective radar measurements. The number of respective radar measurements is, for each identifier, greater than the number of at least one respective location of the identifier with the one or more UWB sensors.

[0005] Each respective location of a respective identifier with the one or more UWB sensors may comprise UWB exchanges each consisting of sending frames between the respective identifier and the one or more UWB sensors. The plurality of radar measurements may comprise, for each respective radar measurement of a respective UWB sensor, a transmission of a frame by the respective UWB sensor, temporally separated from the sending frames between the respective UWB sensor and the respective identifier during the UWB exchanges.

[0006] Each respective localization of a respective identifier with the one or more UWB sensors may be performed within a time interval consisting of a series of time slots. The one or more identifiers may include a priority identifier. The frames of each radar measurement may be transmitted within one of the time slots of the priority identifier.

[0007] The sending of frames of the UWB exchanges between the priority identifier and the one or more UWB sensors can be carried out within slots of the series belonging to a first group. The series can comprise a second group of one or more slots outside the first group. At least one frame of the radar measurement can be transmitted within one of the one or more slots of the second group.

[0008] Each frame of one of the UWB exchanges may be sent at the beginning of a respective time slot. Each frame of the radar measurement of the UWB sensor may be transmitted at the end of a respective time slot. For each UWB sensor, the respective time slots on which the UWB sensor transmits a frame of a radar measurement may be different from the respective time slots on which a frame of a UWB exchange between one of the one or more identifiers and the UWB sensor is sent.

[0009] The radar measurement frames can be transmitted orthogonally to the frames sent from the UWB exchanges.

[0010] Each respective localization of a respective identifier with the one or more UWB sensors may include sending frames from the identifier to each UWB sensor on slots at the beginning and end of the series and, for each UWB sensor, sending a frame from the UWB sensor to the respective identifier on a respective slot in the middle of the series.

[0011] A planning method implemented by a vehicle UWB system comprising one or more UWB sensors and having recorded one or more identifiers, for use of the system according to the method of use is also provided. This method is referred to in the following as a "planning method". The planning method comprises programming the one or more locations and the plurality of radar measurements.

[0012] The planning method may comprise a detection of at least one planning on the same time slot of a transmission of a frame of the radar measurement and a sending of a frame of one of the UWB exchanges. The planning method may also comprise, for each of the at least one planning on the same time slot detected, a time shift of the planning of the transmission of the frame of the radar measurement relative to the sending of the frame of one of the UWB exchanges.

[0013] 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 use method and / or to perform the planning method.

[0014] 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.

[0015] A computer program is also provided. The computer program comprises program code instructions for executing the method of use and / or the planning method, when said program is executed by a processor. Brief description of the figures

[0016] Non-limiting examples will be described with reference to the following figures:

[0017] Lamontre shows an example of programming multiple locations.

[0018] Lamontre shows an example of a localization carried out within a time interval consisting of a series of time slots.

[0019] Lamontre shows a first example of programming a plurality of radar measurements.

[0020] Lamontre shows a second example of programming a plurality of radar measurements.

[0021] Lamontre shows a third example of programming a plurality of radar measurements.

[0022] Shows an example of vehicle use based on locations and radar measurements programmed using the planning process.

[0023] Shows an example of locating an identifier with one or more UWB sensors.

[0024] Lamontre shows an example of determining the number of time slots in each series for an identifier.

[0025] Lamontre shows examples of the frame.

[0026] Lamontre shows an example of a vehicle UWB system. Detailed description

[0027] A method is proposed for operating a vehicle UWB system comprising one or more UWB sensors and having recorded one or more identifiers. This method is referred to in the following as a "method of use", or simply "method". The method comprises a plurality of actions performed periodically. The actions comprise one or more locations. The one or more locations include, for each respective identifier, at least one respective location of the respective identifier with the one or more UWB sensors. The one or more locations are temporally separated. The actions also comprise a plurality of radar measurements. The plurality of radar measurements includes, for at least one respective UWB sensor, a plurality of respective radar measurements.The number (per period) of respective radar measurements is, for each identifier, greater (strictly) than the number (per period) of at least one respective location of the identifier with the one or more UWB sensors.

[0028] UWB may refer to a communications protocol, for example that specified by IEEE 802.15.4.

[0029] A planning method is also provided, which may be executed prior to the method of use. The planning method may comprise a programming of the one or more locations and the plurality of radar measurements. The planning method may be executed once before the execution of the method of use, and the method of use may comprise, periodically, and over several periods, the one or more locations and the plurality of radar measurements according to the programming defined by the planning method. Alternatively, the planning method may be executed several times during the execution of the method of use, for example each time a predetermined number of periods has elapsed, or after a specific event (for example a detection of a new identifier).Each new execution of the planning method may re-schedule the one or more locations and the plurality of radar measurements, and, after each execution of the planning method, the method of use may include the one or more locations and the plurality of radar measurements according to the schedule defined by the new execution of the planning method.

[0030] The method provides improved utilization of vehicle UWB system.

[0031] Indeed, the method allows the carrying out, periodically, of one or more UWB locations and, in parallel, of the plurality of radar measurements. This means that the one or more UWB locations and the plurality of radar measurements are carried out over the same time interval (or "period"), and that this interval is repeated over time. "In parallel" therefore means that over this time interval, which is repeated, the method of use allows both one or more UWB locations and a plurality of radar measurements.

[0032] Furthermore, the method allows one or more of the same sensors to be used both for localization and for radar measurements. Indeed, the at least one UWB sensor is involved in each of the localizations and also in several respective radar measurements. In other words, each respective UWB sensor performing radar measurements is also involved in the one or more localizations, thus ensuring a dual function. This makes it possible to optimize the number of UWB sensors in the system, and avoids using one or more additional UWB sensors to perform the radar measurements that may be desired. In other words, the method makes it possible to exploit already existing UWB sensors, for additional radar functionality to their initial UWB localization functionality.

[0033] Furthermore, the method allows for fine and precise radar measurements. Indeed, over each period, the number of radar measurements for the at least one respective UWB sensor is strictly greater than the number of at least one location of each identifier. This higher number of radar measurements per period, i.e. this higher sampling frequency, offers relatively high radar measurement accuracy. Indeed, a relatively high sampling frequency allows for relatively fine radar detection, making it possible, for example, to precisely detect fine movements and / or displacements.

[0034] The method may include one or more uses of the one or more locations and / or the plurality of radar measurements. For example, one use may be detection of an abnormal event in the vehicle, for example, that a child has been left in the vehicle. For this, the method may include detection of chest movements inside the vehicle (during the child's breathing), for example, after closing the vehicle, and triggering an alarm. In other examples, the use may be gesture detection. For example, UWB sensors may be located on the rear bumper of the vehicle, and the method may include detection by the UWB sensors located on the rear bumper of the vehicle of a foot movement to open the trunk of the vehicle (for example, a foot movement resembling a kick) and opening the trunk after detecting the foot movement.

[0035] For each identifier, and for each period, the number of radar measurements per UWB sensor is strictly equal to or greater than the number of location(s) of each identifier. The number of radar measurements may be, for example, at least twice the number of at least one location. Each radar measurement may comprise an emission of a frame by the UWB sensor, and the frequency of the frame emissions may be greater than a minimum frequency, for example greater than 1 Hz, 10 Hz or 100 Hz.

[0036] A localization of an identifier may comprise a determination of a relative position of the respective identifier with respect to the UWB system. For example, the localization may comprise, for each UWB sensor, a respective distance measurement between the identifier and the UWB sensor. The distance measurement may comprise one or more UWB exchanges each consisting of sending frames between the identifier and the UWB sensor (for example, from the identifier to the UWB sensor and / or from the UWB sensor to the identifier). The localization may then comprise a determination of the relative position of the identifier with respect to the UWB system from the respective distance measurements.

[0037] A radar measurement by a UWB sensor may include a phase of transmission of a frame by the UWB sensor. The transmission of the radar measurement frame may have a duration of between 100 and 520 microseconds. A radar measurement may also include a listening phase. The listening phase may begin simultaneously with the transmission phase (or just after). During this phase, the radar measurement may include detection of a return signal corresponding to the radar measurement frame that was transmitted and is now reflected by one or more objects located around the UWB sensor. Indeed, an emitted frame may be reflected on the one or more objects, and therefore return towards the UWB sensor, which can then detect it as a return signal (also called echo-radar).The radar measurement may then include detection of the presence of one or more objects and / or determination of the position and / or speed of one or more objects from the transmitted frame and the return signal.

[0038] The one or more localizations are temporally separated. This means that at any given time, only one localization is performed. For example, the one or more localizations may be performed successively, one after the other. In other words, each localization may be performed within a respective time interval, and the respective time intervals of each of the localizations may be temporally distinct. Two successive time intervals may follow one another directly (i.e., the end of one localization may correspond to the beginning of the next localization), or they may be separated by a given duration.

[0039] Periodically means that, over a given time interval, the method comprises both the one or more locations and the plurality of radar measurements, and that the method repeats at regular intervals of this given time interval the one or more locations and the plurality of radar measurements. The period represents the duration of this given time interval during which the locations and the plurality of radar measurements are carried out.

[0040] The UWB system may have recorded one or more identifiers other than the one or more identifiers involved in the method. The method may detect that the one or more other identifiers are not within range of the vehicle, and therefore decide not to locate them.

[0041] For each identifier of the one or more identifiers, the number of at least one respective location of the identifier per period may depend on the identifier. For example, the method may include, before the start of the at least one respective location, an exchange with the identifier to determine the number of at least one respective location per period. The exchange may include sending, from the identifier to the UWB system, frequency information of the identifier and calculating, by the UWB system, the number of at least one respective location per period based on the frequency information. The frequency information may be a frequency or a duration that is specific to the identifier.

[0042] The term "identifier" refers to a mobile object identifiable by the vehicle, and for example, the location of which authorizes or not one or more (specific) actions of the vehicle. For example, the identifier can be used to open the vehicle and / or start the vehicle's engine. For example, the method can include opening the vehicle when the identifier is located near the vehicle, or starting the engine when the identifier is in the vehicle. The method can involve as identifier(s) one or more keys and / or one or more smart devices, such as a mobile phone.

[0043] The transmission of each frame of a radar measurement can be temporally separated from the sending of frames during UWB exchanges. The transmissions of frames during radar measurements can therefore be interleaved with the sending of frames during UWB exchanges.

[0044] For example, the scheduling method may include scheduling the one or more locations and the plurality of radar measurements such that the transmissions of the frames during each radar measurement are interleaved with the transmissions of the frames during the UWB exchanges of each location. "Interleaved" means that the transmissions of the frames may be scheduled in time slots distinct from those on which the transmissions of the frames are scheduled (without any overlap).

[0045] The programming may be done over a duration, for example a duration equal to a period, or several times the period. The programming may include a determination, for each of the one or more locations and each of the radar measurements of the plurality, of a respective time interval over this duration over which the location or the radar measurement is carried out. For example, the programming may include a determination of a respective time interval for each location and then a determination, for each radar measurement, of a respective time interval as a function of the respective time intervals of the one or more locations, or conversely the programming may include a determination of a respective time interval for each radar measurement and then, for each location, a determination of a respective time interval as a function of the respective time intervals of the radar measurements.

[0046] 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 time of programming. The length of the duration may be fixed or vary, for example depending on the vehicle's environment.

[0047] Each UWB exchange may consist of sending frames between the identifier and the one or more UWB sensors. The programming of the one or more locations may comprise, for each location, a determination of a time position for each of the sending frames of each of the UWB exchanges of the location. A sending of a frame of a UWB exchange may have a duration of between 60 and 137 microseconds.

[0048] Determining a time position for sending a frame may include determining a start time for sending and an end time for sending 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 frame length and a sending rate. The positioning of the start and end may be a function of the frame length and / or the sending rate.

[0049] The programming of the plurality of radar measurements may comprise, for each radar measurement, a determination of a time position for the radar measurement. The determination of the time position for a radar measurement may be equivalent to that for sending a location frame. The determination of a time position for the radar measurement may for example comprise a determination of a time of start of transmission and end of transmission of the frame, the time between the start and the end being equal to a transmission duration which may be a function of a length of the frame and a transmission rate. The time position of each radar measurement may be distinct from the time positions of the other radar measurements and from the time positions on which sending a location frame is programmed.

[0050] During each radar measurement, the transmission of the frame by a UWB sensor can therefore be temporally separated from the other sendings / transmissions of frames of other radar measurements and from the UWB exchanges of each location. This makes it possible to avoid collisions between radar measurements and locations. Avoiding collisions reduces the risk that a radar measurement and / or a location is false or unexecutable. The temporal separation of the transmissions / transmissions of frames therefore improves the accuracy of the UWB system, in its use and execution.

[0051] For each location, the respective time interval over which the location is performed may consist of a series of time slots. The time slots in the series may have a 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 2 milliseconds. The duration of the slot may be a function of the identifier involved in the location.

[0052] The number of time slots in the series may be a function of the number of UWB sensors in the UWB system. The number of time slots may also be a function of a constant of the UWB system and / or the one or more identifiers. The constant may represent a number of slots at the beginning and end of the series. For example, the number of time slots in the series may be greater than or equal to the sum of the number of UWB sensors in the system and the constant. The UWB system may include a predetermined series of numbers each adapted for the UWB system, and the number of time slots may correspond to one of the numbers in the predetermined series, for example, the number in the predetermined series that is closest to and greater than or equal to the sum.

[0053] The one or more identifiers may include a priority identifier, i.e., one that is predetermined or designated as such in the UWB system. When the one or more identifiers include multiple identifiers, the identifiers may include a priority identifier and one or more secondary identifiers. The priority identifier may have priority operation in the locations, relative to the one or more secondary identifiers. For example, scheduling of locations involving the priority identifier may take precedence over scheduling of locations involving the one or more secondary identifiers. The scheduling may include overriding the scheduling of a location involving one of the one or more secondary identifiers when scheduling of the location is scheduled concurrently with scheduling of a location involving the priority identifier.

[0054] The scheduling may include, for each identifier, scheduling one or more locations among the locations involving the identifier over a respective session corresponding to a time 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. Each session may be divided into blocks. Each block may be divided into several time intervals, and a location involving the identifier may occur within one of these time intervals. Each of the time intervals may be divided into a series of time slots. For each identifier, the scheduling may therefore be based on series of slots respective to the identifier. The respective series of slots of the priority identifier may differ from the respective series of slots of the one or more secondary identifiers.The method of use and / or the scheduling method 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 identifier.

[0055] The scheduling may include scheduling each radar measurement within one of the time slots of one of the respective series of the priority identifier. Scheduling the radar measurement within one of the time slots may include determining the start time of transmission of the frame within the slot and such that the end of the transmission is scheduled before the end of the slot. In other words, the start time of transmission is determined such that the transmission ends before the end of the slot. The frames of each radar measurement may therefore be transmitted within one of the time slots of the priority identifier.

[0056] For each identifier, the sending of frames of the UWB exchanges between the identifier and the one or more UWB sensors can be carried out within time slots of a series of the identifier's session. For the priority identifier, for example, the sending of frames of the UWB exchanges between the identifier and the one or more UWB sensors can be carried out within time slots of a series of the priority identifier's session. For example, each sending can be carried out on a respective time slot. The time slots of the series on which one of the frame sendings is carried out can form a first group. The series can also comprise a second group of one or more time slots outside the first group.For example, the number of frame sendings of the UWB exchanges of each location may be strictly less than the number of time slots of the series, and in this case, the number of the one or more slots belonging to the second group may be equal to the difference between the number of time slots of each series and the number of frame sendings of the UWB exchanges of the location. The use of the time slots is therefore optimized.

[0057] The number of frame sendings of UWB exchanges from each location can be strictly less than the number of time slots in the series when the upper rounding is greater than or equal to zero in the following formula:

[0058] with N the number of UWB sensors in the UWB system, K the duration of a time slot, C the number of time slots per block, X the rounding up and T a predetermined time (e.g. 96 milliseconds).

[0059] The programming of the plurality of radar measurements may comprise, for at least one radar measurement, a programming of the radar measurement within one of the one or more time slots belonging to the second group. The frames of the radar measurements may therefore each be transmitted within one of the one or more time slots belonging to the second group (each on a respective slot of the second group). The programming of a radar measurement may comprise a selection of one of the one or more time slots of the second group and a determination of the start time of transmission of the frame within the selected slot. The selection of a slot may be a function of the other radar measurements of the plurality. For example, the programming may program each radar measurement on a respective slot of the second group.

[0060] Each frame of one of the UWB exchanges may be sent at the beginning of a respective time slot. For example, the scheduling of each location may include, for each sending of a frame of the location, a determination of a sending start time substantially at the same time as the beginning of the respective time slot on which the sending is carried out.

[0061] Each frame of the radar measurement of the UWB sensor may be transmitted at the end of a respective time slot. For example, the scheduling of each radar measurement may include determining a start time for transmitting the frame such that the end of the transmission substantially corresponds to the end of the respective time slot over which the transmission is performed.

[0062] For each UWB sensor, the respective time slots on which the UWB sensor transmits a frame of a radar measurement may be different from the respective time slots on which a frame of a UWB exchange between one of the one or more identifiers and the UWB sensor is sent. The transmission on a different time slot allows the UWB sensor to have time to change configuration between the UWB exchange and the radar measurement. The time between the UWB exchange and the radar measurement may be greater than a predetermined time (for example greater than 1 millisecond). After sending the frame of the UWB exchange, the UWB sensor can change configuration to then carry out the transmission of the frame of the radar measurement and the listening of the return signal. The method therefore makes it possible to reduce the risk, for each UWB sensor, that the time between sending a frame of a UWB exchange and transmitting a frame of a radar measurement (and vice versa) is less than the time to carry out this configuration change.This therefore contributes to improving the use of the UWB system, and in particular UWB sensors.

[0063] Furthermore, sending the UWB exchange frame at the beginning of a respective slot and transmitting the radar measurement frame at the end of a respective slot allows for a spacing of a duration at least equivalent to (or greater than) a time slot, thereby reducing the risk that the duration is less than the time for the UWB sensor configuration change.

[0064] The radar measurement frames may be transmitted orthogonally to the frames sent from the UWB exchanges. Alternatively or additionally, the frames transmitted by each UWB sensor may be orthogonal to the frames transmitted by each of the other UWB sensors. Orthogonality may be achieved by any orthogonality-based frame transmission / sending method to avoid interference in the frame transmissions / sendings. For example, the frames may include a first portion (e.g., synchronization) comprising frame orthogonality parameters. The parameters may be used for decoding the frame. Orthogonality also reduces noise between the radar measurement frames and the UWB exchanges.

[0065] The scheduling method may comprise a detection of at least one scheduling on the same time slot of a transmission of a frame of the radar measurement and of a sending of a frame of one of the UWB exchanges. For this, the method may comprise an analysis of the scheduling of the one or more distance measurements and of the plurality of radar measurements. For example, the detection may comprise a determination that the start time of the transmission is planned between the start and the end of the sending and / or a determination that the end of the transmission is planned between the start and the end of the sending. For each of the at least one scheduling on the same time slot detected, the scheduling method may comprise a time shift of the scheduling of the transmission of the frame of the radar measurement relative to the sending of the frame of one of the UWB exchanges.The time shift may include a calculation of a shift duration so that the transmission is scheduled before or after sending. For example, the transmission may be scheduled to start at a time t1, and the shift may include a calculation of a time shift Δt and a rescheduling for the start of the transmission at a time t2= t1+ Δt. The time shift makes it possible to avoid the collision between the transmitted frame of the radar measurement and the sent frame of the UWB exchange, which improves the utilization of the UWB system.

[0066] 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.

[0067] 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.

[0068] 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 use method and / or to execute the scheduling method. The UWB system may be configured to, after programming, send one or more commands to each UWB sensor according to the programming in a programming execution phase. The one or more commands may comprise a request to send a frame of a UWB exchange and / or to transmit a frame of a radar measurement.

[0069] A computer program is also provided. The computer program comprises program code instructions for executing the method of use and / or the method of planning, when said program is executed by a processor. The computer program may be stored on a memory. The UWB system may comprise the processor and / or the memory.

[0070] Examples will now be given with reference to Figures 1 to 10.

[0071] Lamontre an example of the programming of several localizations. Lamontre, for each identifier 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 identifier, the method of use comprises a localization 121, 122, 123 of the identifier with the one or more UWB sensors. The localization 121 involves the identifier 101, the localization 122 the identifier 102 and the localization 123 the identifier 103. Each localization comprises an active RF part (acronym for Radio Frequency). The active RF part corresponds to the portion of the time interval on which the localization comprises UWB exchanges.In the figure, the active part FT 131 corresponds to the location involving the identifier 101, the active part FT 132 corresponds to the location involving the identifier 102 and the active part FT 133 corresponds to the location involving the identifier 103. The figure also shows other active parts FT 134 corresponds to the location involving other identifiers not shown.

[0072] The figure 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 an identifier. 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).

[0073] The localization performed within the interval 205 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 identifier involved in the localization can be a priority identifier or a secondary identifier. The localization performed within the interval 205 comprises UWB exchanges between the identifier and the one or more UWB sensors. Each UWB exchange consists of sending frames between the identifier and the one or more UWB sensors. The sending frames of the UWB exchanges between the identifier and the one or more UWB sensors are performed within slots of the series belonging to a first group. The first group consists of 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. The frames 202, 221 and 222 are sent from the identifier to each of the one or more identifiers. On the time slots 214, each of the one or more identifiers carries out a respective sending of a frame to the identifier. Then, the sending of frame 225 is carried out on slot 215 and the sending of frame 226 on slot 216. The frames 225 and 226 are sent from the identifier to each of the one or more identifiers. Frames 220, 221, 222, 225 are sent at the beginning of time slots 210, 211, 212, 215. The series also includes a second group of one or more slots 213, 217 outside the first group. At least one frame of the radar measurement may be transmitted within one of the one or more slots of the second group 217.

[0074] Shows a first example of programming a plurality of radar measurements. Shows a session 230 of an identifier, and in particular a block 229 of this session. The block 229 comprises 18 time slots. In this first example, the method comprises a plurality of radar measurements. The plurality of radar measurements includes, for two UWB sensors 231, 232 (“CPD1” and “CPD2”), several respective radar measurements. The number of respective radar measurements is, for each identifier, greater than the number of at least one respective location 234 of the identifier with the one or more UWB sensors. The figure shows the session 230 of the priority identifier, and in particular the series 233 of time slots of the time slot over which the location 234 involving the priority identifier is carried out. Radar measurements 231', 232' are carried out within the time slots of series 233 of the priority identifier.Each radar measurement comprises the transmission of a frame within one of the one or more slots belonging to the second group 217. The UWB sensor 231 transmits the frames 231' and the UWB sensor 232 the frames 232'. The frames 231' and 232' are transmitted within one of the slots 217 belonging to the second group. The duration between two radar measurements 235 is substantially equal to the duration of the location time interval 234, i.e. 16 milliseconds in this example. The frames 231', 232' of the radar measurements of each of the UWB sensors 231, 232 are transmitted at the end of one of the slots 217. The duration between the sending of frame 236 and the transmission of frame 231' is greater than 1 millisecond.

[0075] La shows a second example of programming a plurality of radar measurements. La also shows a session 230 of an identifier, and in particular a block 229 of this session comprising 18 time slots. In this second example, for each of the UWB sensors, the respective time slots on which the UWB sensor transmits a frame of a radar measurement are different from the respective slots on which a frame of a UWB exchange is sent between one of the one or more identifiers and the UWB sensor. The figure shows in this example, over the location time slot 234, the UWB exchanges between the identifier of the session 230 and two UWB sensors 231, 232. The figure shows in detail the sending / transmission of frame 241 for the UWB sensor 231 and the sending / transmission of frame 242 for the UWB sensor 232 during the location 234.

[0076] The localization 234 comprises two sendings of frames 236 from the session identifier 230 to each of the two UWB sensors 231, 232 on slots (“0” and “1”) at the beginning of the series of slots of the interval. The frames are sent from the identifier to each of the UWB sensors, and the figure shows the frames 236 received by each of the UWB sensors 241, 242. For each UWB sensor, the localization 234 then comprises a sending of a frame from the UWB sensor to the identifier on a respective slot in the middle of the series. The localization comprises a first sending of a frame 237 from the UWB sensor 241 to the identifier on slot “2” and a second sending of a frame 238 from the UWB sensor 242 to the identifier on slot “3”. The localization then comprises two sendings of frames 239 from the session identifier 230 to each of the two UWB sensors 241, 242 on slots at the end of the series (“Nresp+2” and “Nresp+3”).The UWB sensor 231 transmits a frame 243 on slot “3”.

[0077] Each of the frames 236, 237, 238 and 239 is sent at the beginning of the respective slot (“0”, “1”, “2”, “3”, “Nresp+2”, “Nresp+3”) on which it is sent and each of the frames 243, 244 is transmitted at the end of the respective slot (“3”, “4”) on which it is transmitted. The UWB sensor 241 transmits a frame 243 of a radar measurement on the slot “3”. The UWB sensor 241 therefore transmits the frame 243 on a slot which differs from the slots “0”, “1”, “2”, “Nresp+2”, “Nresp+3” on which a frame of a UWB exchange involving the UWB sensor 231 is sent. Similarly, for the UWB sensor 242, it transmits a frame 244 of a radar measurement on the slot “4” and this slot “4” differs from the slots “0”, “1”, “3”, “Nresp+2”, “Nresp+3” on which a frame of a UWB exchange involving the UWB sensor 232 is sent.For the UWB sensor 231, the duration between sending the frame 237 to the identifier and transmitting the frame 243 of the radar measurement is greater than 1 millisecond. This duration allows the UWB sensor 231 to change configuration between the UWB exchange and the radar measurement. Similarly, for the UWB sensor 232, the duration between sending the frame 238 to the identifier and transmitting the frame 244 of the radar measurement is greater than 1 millisecond, which allows the UWB sensor 232 to change configuration between the UWB exchange and the radar measurement.

[0078] Lamontre a third example of programming a plurality of radar measurements. The figure shows the programming of a respective location for each identifier over a session. In particular, the figure shows the sessions of three identifiers 301, 302, 303. For each identifier 301, 302, 303, the figure shows a block 301', 302', 303' of the identifier's session each comprising 18 time intervals. Location 311 involves identifier 301, which is the priority identifier in this example, and is performed on the first time slot of block 301' of identifier 301's session. Location 312 involves identifier 312 and is performed on the third time slot of block 302' of identifier 302's session. Location 313 involves identifier 303 and is performed on the penultimate time slot of block 303' of identifier 303's session. The figure also shows the RF active portion 340 of each location.The figure also shows the plurality of radar measurements programmed for the UWB sensors 320 (“CPD1”) and 321 (“CPD2”).

[0079] The planning method comprises a detection of at least one planning on the same time slot of a respective transmission of a frame of the radar measurement and of a sending of a frame of one of the UWB exchanges. For each of the at least one planning on the same time slot detected, the planning method comprises a time shift of the planning of the transmission of the frame of the radar measurement with respect to the sending of the frame of one of the UWB exchanges. For example, the planning method comprises a detection of a planning of the radar measurement 321 by the UWB sensor 320 at the same time as the location 344 and on a time slot already used by a UWB exchange involving the UWB sensor 320.The planning method may then comprise a shift 321' of the radar measurement 321 to another time slot that is not used by the UWB sensor 320 (for example to a time slot of the second group or a slot used by a UWB exchange involving another sensor). Alternatively, the planning method may comprise a shift 321' of the radar measurement 321 outside the location 344, for example here by advancing the radar measurement 321 so that it is carried out before the location 344.The scheduling method comprises analogous steps for preventing the scheduling of the radar measurement 331 at the same time as 341 (by moving the measurement 331 back), of the radar measurement 332 at the same time as 342 (by moving the measurement 332 forward or backward), of the measurement 333 at the same time as 343 (by moving the measurement 333 forward to a time slot of the second group or a slot used by a UWB exchange not involving the sensor 330), the radar measurement 334 at the same time as 345 (by moving the measurement 334 forward to a time slot of the second group or a slot used by a UWB exchange not involving the sensor 330), the radar measurement 335 at the same time as 346 (by moving the measurement 335 forward to a time slot of the second group or a slot used by a UWB exchange not involving the sensor 330) and the radar measurement 321 at the same time as 347 (by advancing measurement 335 to a time slot of the second group or a slot used by a UWB exchange not involving sensor 320).

[0080] Shows an example of vehicle use based on locations and radar measurements programmed using the planning process.

[0081] During the driving / running of the vehicle engine, the use includes a location S10 in the cabin of the identifier. After a stable position S20 of the identifier in the cabin, the use includes a re-evaluation S11 of the location in the cabin of the identifier. Then, the use includes a change S21 of the position of the identifier in the cabin and then a new location S10 of the identifier in the cabin. After the engine is switched off, the use again includes a stable position S20 of the identifier in the cabin, a re-evaluation S11 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 location S10 of the identifier in the cabin. At the time of door closing, the use includes a DTC / LPD buffering S15.The use also includes an external location S15 of all identifiers after the identifier is located S22 outside. The use also includes an active CPD / LPD moment S17 after closing, at the same time as the location S23 of all identifiers outside the vehicle. At the time of closing, the use may include one or more radar measurements to check for the absence of occupants who may have remained in the vehicle after closing.

[0082] Shows an example of localization of an identifier with one or more UWB sensors. The localization comprises two sendings 410 of a frame on two first time slots from the identifier 400 to each of the UWB sensors 401, 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 two last time slots from the identifier 400 to each of the UWB sensors 401, 402, 403.

[0083] Shows an example of determining the number of time slots in each series for an identifier. The determination may be based on the application of a standard, for example, using table 500. The determination includes determining a time slot duration 501 for the identifier. For example, the identifier may communicate its duration to the UWB system. Table 500 includes a series of numbers 502 each adapted for the UWB system. The determination includes determining a number of time slots per time interval from the series 502. 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 500 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, on this table 500, 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.

[0084] The show three examples of frames 601, 602, 603. Each of the examples comprises a first portion “SYNC” and “SFD” and a marker 604. After the marker 604, each example comprises a second portion comprising, for the first example, a portion “PHR” and “PSDU”, for the third example, a portion “STS”, and for the second example, a portion “STS” followed by a portion “PHR” and “PSDU”. The first example 601 may be a frame sent during a UWB exchange between the identifier and a UWB sensor. The third example 603 may be a frame transmitted from a radar measurement.

[0085] The figure shows an example of a UWB system 710 of a vehicle 700. The UWB system includes multiple UWB sensors 720 positioned at the front of the vehicle, at the rear of the vehicle, or in the cabin of the vehicle. The figure also shows an identifier 730. A location includes UWB exchanges 740 between the identifier 730 and each of the UWB sensors 720.

Claims

Method of using a vehicle UWB system comprising one or more UWB sensors and having recorded one or more identifiers, the method periodically comprising: one or more locations, the one or more locations including, for each respective identifier, at least one respective location of the respective identifier with the one or more UWB sensors, the one or more locations being temporally separated; and a plurality of radar measurements, the plurality of radar measurements including, for at least one respective UWB sensor, several respective radar measurements, the number of respective radar measurements being, for each identifier, greater than the number of at least one respective location of the identifier with the one or more UWB sensors. A method according to claim 1, wherein each respective localization of a respective identifier with the one or more UWB sensors comprises UWB exchanges, each consisting of frame transmissions between the respective identifier and the one or more UWB sensors, the plurality of radar measurements comprising, for each respective radar measurement of a respective UWB sensor, the transmission of a frame by the respective UWB sensor, temporally separated from the frame transmissions between the respective UWB sensor and the respective identifier during the UWB exchanges. A method according to claim 2, wherein: each respective localization of a respective identifier with the one or more UWB sensors is carried out within a time interval consisting of a series of time slots, and the one or more identifiers include a priority identifier, the frames of each radar measurement being emitted within one of the time slots of the priority identifier. A method according to claim 3, wherein the UWB exchange frame transmissions between the priority identifier and one or more UWB sensors are carried out within slots of the series belonging to a first group, the series comprising a second group of one or more slots outside the first group, at least one frame of the radar measurement being transmitted within one or more slots of the second group. A method according to claim 3 or 4, wherein: each frame of one of the UWB exchanges is sent at the beginning of a respective time slot, each frame of the radar measurement of the UWB sensor being emitted at the end of a respective time slot, and for each UWB sensor, the respective time slots on which the UWB sensor emits a frame of a radar measurement are different from the respective time slots on which a frame of a UWB exchange is sent between one or more identifiers and the UWB sensor. A method according to any one of claims 2 to 5, wherein the frames of the radar measurements are transmitted orthogonally to the frames sent from the UWB exchanges. A method according to any one of claims 2 to 6, wherein each respective location of a respective identifier with the one or more UWB sensors comprises: sending frames from the identifier to each UWB sensor on slots at the beginning and end of the series; and for each UWB sensor, sending a frame from the UWB sensor to the respective identifier on a respective slot in the middle of the series. Planning method implemented by a vehicle UWB system comprising one or more UWB sensors and having recorded one or more identifiers, for use of the system according to any one of claims 1 to 7, the method comprising programming one or more locations and the plurality of radar measurements. Planning method according to claim 8, the method comprising: detecting at least one planning on the same time slot of an emission of a frame of the radar measurement and a sending of a frame of one of the UWB exchanges; and for each of the at least one planning on the same time slot detected, a time offset of the planning of the emission of the frame of the radar measurement with respect to the sending of the frame of one of the UWB exchanges. Vehicle UWB system comprising one or more UWB sensors and configured to be used according to the method of any one of claims 1 to 7 and / or to perform the method of claim 8 or 9. UWB sensor for vehicle UWB system and configured for use of the system according to the method of any one of claims 1 to 7 and / or to perform the method of claim 8 or 9. Computer program comprising program code instructions for executing the method according to any one of claims 1 to 7 and / or according to claim 8 or 9, when said program is executed by a processor.

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