UWB location planning with offset

Abstract

Title: UWB Location Scheduling with Offset A scheduling method is proposed, implemented by a vehicle system comprising one or more UWB sensors. The system has stored a plurality of wearable identifiers. The system and each wearable identifier are configured to communicate using the UWB and BLE communication protocols. The method includes receiving, for each wearable identifier, a respective schedule comprising the repetition, at a respective frequency, of UWB locations with the vehicle's UWB system. The method includes calculating a time offset from the respective schedule of at least one wearable identifier to optimize the concatenation of the UWB locations of the wearable identifiers. The method includes sending, to at least one wearable identifier, a command to apply the calculated time offset using the BLE communication protocol.The process offers improved utilization of the vehicle UWB system [Fig. 3].

Description

Title of the invention: UWB location planning with offset technical field

[0001] This disclosure relates to a method for planning and a method for using a vehicle system, a vehicle system configured to perform or be used according to such methods, and a computer program for performing such methods. Technical background

[0002] Vehicles equipped with a system comprising one or more UWB (Ultra Wide Band) sensors installed in the vehicle now exist. Such a vehicle system typically records a set of wearable identifiers (such as key fobs or third-party devices like mobile phones or smartwatches) and is then able to determine the position of each of these wearable identifiers from UWB localizations performed between each of the wearable identifiers and the system's UWB sensors. Each of these UWB localizations generally includes UWB exchanges between the wearable identifier involved and each of the vehicle's UWB sensors.These UWB exchanges can, for example, determine the respective distances between the wearable device and each UWB sensor (e.g., using a time-of-flight measurement), and the system can then deduce the wearable device's location. The vehicle system is thus capable of locating several wearable devices simultaneously in real time (such as the driver's key fob and a passenger's mobile phone) and, based on the location of these devices, executing various vehicle functions, such as unlocking the doors and / or starting the vehicle when a user approaches.

[0003] To perform these UWB localizations, each wearable device can be configured to send its respective programming to the vehicle system, for example, when the vehicle enters a certain perimeter around it. The vehicle system and the wearable device can then be configured to perform the UWB localizations according to the respective programming established. [Fig. 1] shows an example of such programming received for a set of two wearable devices registered by the vehicle system: a first programming of 100 for a first wearable device and a second programming of 200 for a second wearable device. The programming received from each wearable device includes, Over a predetermined period divided into periods (111, 112, and 113 for the initial programming of 100), a UWB location is assigned to each period of the predetermined duration (UWB location 121 for period 111, UWB location 122 for period 122, and so on). Each of these periods is generally also divided into a predetermined number of slots (12 slots per period in this example for the first wearable identifier, and 8 slots per period for the second), and the programming includes, for each location, the slot within the period on which the location is scheduled. For example, in this example, the UWB locations are always scheduled for the first slot of the period for both wearable identifiers. Each slot is itself divided into a series of time intervals 131, 132, and so on.(called in English "slot"), within which, during the UWB localization performed on this slot, the UWB exchanges between the portable identifier involved and the UWB sensors of the system are carried out.

[0004] After receiving the various programs, the vehicle and the involved handheld devices are configured to execute the programmed UWB locations. However, the UWB locations involving the different handheld devices are generally spaced apart. For example, as illustrated in [Fig. 2], which reproduces the programming examples from [Fig. 1], the program involving the first handheld device may already be running when the second handheld device sends its program to the vehicle, and its program may therefore be executed with a delay relative to that of the first handheld device (the different planned locations are shown on the same timeline 300 in [Fig. 2]). During execution, the UWB locations involving the two handheld devices are thus spaced apart, which is not optimal.Firstly, such a disordered execution leaves little space available to run other UWB locations. Therefore, adding UWB locations with a new portable identifier is difficult without risking collisions between running UWB locations. Secondly, this execution requires the vehicle system components involved to power on and off very frequently (after each location), increasing power consumption and wear.

[0005] That is why there is a need for an improved vehicle system. Summary

[0006] A planning method is proposed, implemented by a vehicle system comprising one or more UWB sensors (hereinafter referred to as the "planning method," or simply the "method"). The system has stored a plurality of wearable identifiers. The system and each wearable identifier are configured to communicate using the UWB and BLE communication protocols. The method includes receiving, for each wearable identifier, a program The method involves repeating UWB locations at a respective frequency using the vehicle's UWB system. It includes calculating a time offset for the respective programming of at least one wearable device identifier (WDI) to optimize the concatenation of the WDI's UWB locations. The method also includes sending a command to at least one WDI to apply the calculated time offset using the BLE communication protocol.

[0007] The plurality of portable identifiers may include a first portable identifier and a second portable identifier. The time offset can be calculated to temporally conjoin the UWB locations involving the first portable identifier and the UWB locations involving the second portable identifier.

[0008] The plurality of portable identifiers may further include at least one third portable identifier. The method may include calculating a time offset and sending an application command for each of the respective programming of the second and third portable identifiers. The time offset may be calculated to temporally concatenate the UWB locations involving the first, second, and third portable identifiers.

[0009] The time lag can be applied from a future period separated from a current period at the time of execution of the process. The spacing between the current period and the future period can be equal to a predetermined number of periods.

[0010] The respective frequencies with which the UWB locations are repeated can each represent a respective period equal to a multiple of a predetermined duration, for example equal to a multiple of 96 milliseconds.

[0011] The calculation and sending steps can be repeated at least every 25 seconds.

[0012] The calculation and sending steps can be repeated each time a new respective programming for a new portable identifier.

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

[0014] A vehicle system comprising one or more UWB sensors is also proposed. The UWB system is configured to execute the planning process and / or to be used according to the operating process.

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

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

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

[0018] [Fig.1] and [Fig.2] illustrate an example of an existing UWB location planning solution with handheld devices.

[0019] Figure [Fig. 3] illustrates an example of a flowchart of the planning process.

[0020] Figure 4 illustrates an example of a vehicle system.

[0021] Figures [Fig. 5] and [Fig. 6] illustrate examples of implementation of the planning process. Detailed description

[0022] With reference to the flowchart in [Fig. 3], a planning method is proposed, implemented by a vehicle system comprising one or more UWB sensors. The system has stored a plurality of wearable identifiers. The system and each wearable identifier are configured to communicate using the UWB and BLE communication protocols. The method includes receiving, for each wearable identifier, a respective program comprising a repetition, at a respective frequency, of UWB locations with the vehicle's UWB system. The method includes calculating, for each wearable identifier, a time offset for the respective program to optimize the concatenation of the UWB locations of the wearable identifiers. The method includes sending, for each wearable identifier, a command to apply the calculated time offset using the BLE communication protocol.

[0023] The method offers improved use of the vehicle's UWB system.

[0024] Indeed, applying the calculated offset by at least one handheld identifier allows the UWB locations of the handheld identifiers to be grouped, which improves the system's operation. First, optimizing the concatenation of UWB locations leaves more free space between groups of UWB locations executed consecutively, thus allowing for the execution of additional UWB locations. This reduces the risk of collision when a new handheld identifier is added. Second, this execution allows the vehicle system components involved to switch off and on a reduced number of times (after each group of locations executed consecutively), thereby reducing energy consumption and wear. The method thus improves the system's operation on several levels.

[0025] A method for using a vehicle system comprising one or more UWB sensors is also proposed. The system has stored a plurality of portable identifiers. The method of use includes executing the planned UWB locations according to the planning method. The method of use can be executed by the vehicle system and / or the plurality of portable identifiers.

[0026] After or during the execution of the localization operations, the method of use may include determining the position of each of the wearable identifiers from the localization operations that have been performed. For example, for each wearable identifier, the execution of a localization operation involving the wearable identifier may include providing a relative position of the wearable identifier with respect to the vehicle system (hereinafter also referred to as the "UWB system"). For example, the localization may include, for each UWB sensor (or anchor), a respective distance measurement between the wearable identifier and the UWB sensor, and a determination of the relative position of the wearable identifier with respect to the UWB system from the respective distance measurements between the wearable identifier and each of the UWB sensors. The determined position may vary over time.For example, each location can provide the position of a wearable identifier relative to the UWB system at a given time, and the set of locations involving this wearable identifier that are executed can provide an evolution of the position of this wearable identifier over time. The usage process can thus determine an evolution of the position of all wearable identifiers.

[0027] After the location operations are performed, the operating method may include one or more uses of the relative positions of the determined portable identifiers. For example, the operating method may include activating one or more vehicle functions based on the relative positions of the portable identifiers. For example, the function may include locking the vehicle when it is determined that the portable identifiers are outside the vehicle, for example, after a predetermined time has elapsed between the time it is determined that each of the portable identifiers is outside. In some examples, the function may include selectively unlocking one or more vehicle openings (for example, a driver's door, a passenger's door, or a vehicle trunk) based on the relative positions of the determined portable identifiers.For example, the functionality might include unlocking the driver's door and the vehicle's trunk when one of the wearable devices approaches the driver's door (e.g., the key fob) and another wearable device (e.g., a third-party device) approaches the trunk (i.e., when two users carrying these devices approach these openings, for example, simultaneously or one after the other). In other examples, the... The functionality may include unlocking the driver's door and / or passenger doors (for example, when one or more users approach these doors), and, for each user, making one or more adjustments (for example, adjusting the headrest height or seat position) based on a user access zone (for example, based on the door the user approached). In other examples, the functionality may include activating one or more vehicle functions, such as turning on the music or adjusting the mirrors to suit the person wearing the portable identifier positioned near the driver's seat. The method of use may include any combination of these functionality examples.

[0028] The planning method is now discussed. The steps of the planning method can be executed by the vehicle system.Each step of this process is now discussed in more detail.

[0029] The UWB system has registered a plurality of portable identifiers (or portable devices). The term "portable identifier" refers to a mobile object identifiable by the vehicle, and whose location, for example, authorizes or prevents one or more (specific) actions of the vehicle. For example, the identifier can be used to unlock the vehicle and / or start the vehicle's engine. For example, the process can include unlocking the vehicle when the identifier is located near the vehicle, or starting the engine when the identifier is inside the vehicle. The portable identifiers registered by the system can include at least one remote key fob for the vehicle. The portable identifiers registered by the system can also include one or more third-party devices, i.e., devices manufactured by a company other than the one manufacturing the vehicle's UWB system.For example, one or more third-party devices may include smart devices, such as smartwatches or mobile phones.

[0030] The vehicle and each wearable identifier can be configured to communicate using the UWB (Ultra Wide Band) communication protocol. UWB can refer to a communication protocol, for example, that specified by IEEE 802.15.4. The vehicle and one or more wearable identifiers (for example, all of them) can also be configured to communicate using one or more other communication protocols, such as the BLE (Bluetooth Low Energy) communication protocol or the NFC (Near Field Communication) communication protocol.

[0031] The method comprises, for each portable identifier, a reception S10 of a respective UWB location program with the vehicle's UWB system by one or more UWB sensors. The received program may be a digital data item including information such as the repetition, at a respective frequency, of UWB locations with the vehicle's UWB system. The respective program received for each portable identifier may include, for each UWB location in the program, digital data defining a temporal positioning of the UWB location, for example, on a time axis (or line). For example, the respective program received for each portable identifier may include, for each UWB location in the program, the repetition frequency of the locations, and / or the start and end times of the first (or each) location entered on said time axis.The time axis can represent a future duration that has not yet elapsed at the time the schedule is received. For example, the schedule might include, for a set of successive periods (of substantially equal duration), a UWB location for each period. In particular, each period might include an identical number of successive slots (of substantially equal duration), and the UWB location might be scheduled within one of these slots. The numeric data might then include, for each UWB location, the slot number on which the UWB location is scheduled. Alternatively or additionally, the numeric data might include a start time for the slot on which the location is scheduled and an end time for that slot.Alternatively or additionally, the numerical data defining each location may include numerical data defining each of the UWB emissions from the UWB location. For example, the numerical data may designate a start time and an end time for each UWB exchange from the UWB location.

[0032] In examples, the respective frequencies at which the UWB locations are repeated each represent a respective period equal to a multiple of a predetermined duration, for example, equal to a multiple of 96 milliseconds (e.g., 96, 192, or 288 ms). Thus, each wearable identifier can perform locations spaced at intervals equal to a multiple of this predetermined duration.

[0033] Each registered handheld identifier can be configured to send its respective programming, which is received by the UWB system. Each registered handheld identifier can be within a given perimeter around the vehicle, allowing its respective programming to be sent to the UWB system. The respective programming can be sent by the handheld identifiers and received by the system. UWB uses a companion communication protocol (such as the BLE communication protocol). The UWB system may also have registered one or more other wearable identifiers (or devices), which may, for example, currently be out of range. The consideration of these other wearable identifiers is discussed later.

[0034] After or during the S10 reception, the method may include recording all received programming, for example, in system memory. The programming received from each handheld identifier may include the respective repetition frequency, the number of slots per period, and / or the duration of each slot or period. For each period, the programming may also include an indication of the slot on which the UWB location is programmed for that period (this slot may be fixed). This information may be specific to the handheld identifier. The handheld identifier may be configured to enforce certain parameters of its programming.

[0035] Each UWB location may include one or more UWB exchanges between the wearable identifier and the system's UWB sensors. Each UWB exchange may consist of frame transmissions between the identifier and one or more UWB sensors. The programming of one or more locations may include, for each location, the determination of a time position for each frame transmission of each of the location's UWB exchanges. A frame transmission of a UWB exchange may have a duration of between 60 and 137 microseconds.

[0036] After the S10 reception, the method includes the S20 calculation of the time offset of the respective programming of at least one portable identifier in order to optimize the concatenation of the UWB locations of the portable identifiers. The expression "optimize the concatenation" means optimizing the grouping, that is, the successive execution (with few or no interruptions), of the UWB locations involving the different portable identifiers (to temporally concatenate these UWB locations). In other words, the expression "optimize the concatenation" means optimally organizing the UWB locations (also called UWB radio exchange trains) for each of the portable identifiers in a temporally optimal manner. The optimization performed focuses on maximizing the "grouping" or "concatenation" of the UWB locations.In other examples, this criterion might not be the only criterion used, and the process could apply other optimization criteria (for example, within the framework of multi-RAN management constraints).

[0037] For example, the calculation may include determining a temporal distance between one of the UWB locations involving at least one offset portable identifier, and a UWB location involving another portable identifier, and then estimating the temporal offset to be applied to reduce this distance temporally determined (for example, to reduce it to zero, i.e., to temporally concatenate the UWB location involving at least one offset portable identifier and the one involving the other portable identifier). The expression "temporally concatenate" means to match the start time of the first UWB location with the end time of the next UWB location, for example, exactly (i.e., without interruption between the two locations), or with a slight predetermined gap (for example, a short duration relative to the period or time slot). The start and end times can be those of the time slots on which the UWB locations are planned (these may differ from the end times of the last UWB exchanges performed during the locations).The time offset is applied to the entire respective program; that is, each UWB location of the program involving at least one portable identifier is offset (the offset is applied to all subsequent UWB locations). The S20 calculation of the time offset can also take into account any other additional optimization criteria.

[0038] In a first implementation example, the plurality of portable identifiers comprises a first portable identifier and a second portable identifier. The time offset can be calculated to temporally conjoin the UWB locations involving the first portable identifier and the UWB locations involving the second portable identifier. For example, the calculation may include determining the time spacing between the locations involving the first portable identifier and the locations involving the second portable identifier, and then calculating the offset to reduce this time spacing (for example, to conjoin, i.e., to place end to end, the locations of the two identifiers).Since the localizations are performed periodically, the process may include calculating the offset to be applied for one of the periods, and then applying this calculated offset to all subsequent periods (this also working).

[0039] In a second implementation example, the plurality of portable identifiers may further include at least one third portable identifier (in addition to the first and second portable identifiers). In this case, the method may include calculating a time offset and sending an application command for each of the respective schedules of the second and third portable identifiers (these being offset to align their locations with those of the first portable identifier). In this case as well, the time offset calculated for each of the first and second portable identifiers may be calculated to temporally align their UWB locations with those of the first portable identifier. The time offset applied to the first portable identifier may be different from that applied to the second.

[0040] After calculation S20, the method includes sending S30, to at least one handheld identifier, the command to apply the calculated time offset. The application command is sent using the BLE communication protocol; that is, it can be sent as a message encoded in this BLE protocol. The at least one handheld identifier can be configured to execute the received command, that is, to apply the calculated offset to its respective programming, and thus to the UWB localizations that will be implemented subsequently. This step can be carried out in any way. For example, the transmission can include encoding the calculated time offset in a BLE message, and then sending this message to the at least one handheld identifier.

[0041] In some examples, it is possible that no significant offset is deduced. For example, the process may run cyclically with a repetition of the process steps (in particular step S20 of the time offset calculation), and, for at least one repetition, the process may not apply the calculated time offset. For example, the calculated time offset may not be greater than 1 / 3 ms. This may be the case when an initial recalibration has been performed to synchronize the radio trains and the clock drift is not significant between the different transmitters constituting the adjacent trains. In this case, step S30 may be skipped for one cycle.For example, at each repetition, the process may include, after the S20 time offset calculation step, a comparison of the calculated time offset with a predetermined threshold (e.g., 1 / 3 ms), and, an execution of the S30 step only when the comparison indicates that the calculated time offset is greater than the predetermined threshold.

[0042] In examples, the calculation steps S20 and transmission steps S30 can be repeated each time a new programming is received S10 for a new wearable identifier. For example, this new wearable identifier may initially be out of range of the vehicle, and the user wearing it may approach the vehicle. This new identifier may also be registered by the UWB system (in addition to the others). As the user approaches the vehicle, once the new identifier enters the BLE perimeter around the vehicle, the new identifier can be configured to begin locating the vehicle. To do this, the new identifier can be configured to send its respective programming to the UWB system. The method may then include receiving this respective programming for this new identifier (as for the other identifiers in step S10).In this case, the process may include a repetition of steps S20 and S30 with the respective new programming received for the new identifier. For example, the repetition of the S20 calculation may include determining the spacing between the UWB locations involving the new identifier and those involving the others, and determining a time offset to reduce this spacing. spacing. The process can then include sending S30 the time offset calculated for this new portable identifier to this new portable identifier.

[0043] In examples, the time offset can be applied from a future period separated by a current period at the time of process execution. The spacing between the current and future periods can be equal to a predetermined number of periods. This timing improves system operation, since it allows system latency to be taken into account. For example, the system can request the execution of the offset for UWB locations scheduled after the execution of a predetermined number of UWB locations (for example, after the next two or three locations). To this end, the command sent can also include the desired spacing from the present time (for example, expressed in periods or time). In this case, at least one portable identifier can be configured to wait for the execution of this predetermined number of locations before executing the offset.Alternatively, the system can send the command only after the predetermined number of locations have been executed, and the portable identifier can in this case be configured to execute the shift directly upon receipt of the command (and therefore for all subsequent locations).

[0044] In examples, the calculation and sending steps can be repeated at least every 25 seconds. This improves scheduling and reduces the risk of collisions. Indeed, each clock drift introduces a potential collision risk. As recommended by the IEEE 802.15.4z standard, the UWB PHY clock is set to + / - 20 ppm (2.4 ms / minute). The maximum elapsed time of 25 seconds (error less than or equal to 1 ms) between two repetitions is therefore a reasonable time interval for implementing a time offset to compensate for this error.

[0045] Examples will now be described with reference to Figures 3 to 6.

[0046] As part of the new generation of passive opening / starting systems For vehicles (called PEPS) using BLE and UWB technologies to connect to the vehicle and then use the established UWB communication as a means of locating an access device (such as a smartphone, smartwatch or key fob), multiple concurrent sessions on the same UWB telemetry network can lead to a decrease in quality of service.

[0047] The planning process aims to optimize the use of the UWB communication time space and, consequently, to improve the quality of telemetry by avoiding collisions between competing attempts to locate access to the system.

[0048] BLE communication is an authenticated / secure channel. BLE communication is always active before UWB communication is activated and remains active during the UWB telemetry session. In particular, at a reasonable distance from the vehicle, BLE communication is used to trigger UWB communication via a dedicated (out-of-band) message.

[0049] Figures 4 and 5 illustrate a first example of implementation of the planning method. In this example, the vehicle system 600 includes six UWB sensors 610. The handheld identifiers 101 and 201 (or access devices) are registered by the vehicle system 600. The system 600 and each of the handheld identifiers 101 and 201 are configured to communicate using the UWB and BLE communication protocols. The method includes receiving, for each handheld identifier, a respective program comprising a repetition, at a respective frequency, of UWB locations with the vehicle's UWB system. As illustrated in [Fig.5], the system receives programming 100 for wearable ID 101 and programming 200 for wearable ID 201. The respective programming 100 and 200 can be exchanged with the vehicle system once the wearable IDs have initiated a UWB location session.Each portable identifier defines its own location frequency. The programming structure and duration depend on the device's capabilities (slot duration), the telemetry cycle structure, and the number of responders in the telemetry cycle. In this example, the respective programming received from the two portable identifiers is shown in [Fig. 1].

[0050] As explained with reference to [Fig.2] above, in the absence of use of the planning process, since the initiation time of the programs depends only on the portable identifier, the two starting points of the respective programs of the portable identifiers are misaligned, which results in a non-optimal use of time.

[0051] As illustrated in [Fig. 5], the scheduling method optimizes the occupancy time of UWB locations by grouping UWB locations as much as possible. Specifically, the method involves calculating a time offset 710 for the respective programming of at least one portable identifier to optimize the concatenation of the UWB locations of the portable identifiers. In particular, in this example, the respective programming of portable identifier 201 is offset so that the start time of each UWB location in this programming (locations 221, 222) corresponds to the end time of a UWB location involving portable identifier 101. The method then includes sending a command to portable identifier 201 to apply the calculated time offset 710 using the BLE communication protocol.Location 221 is therefore executed immediately after location 121, and location 222 immediately after location 123, which prevents the system from having to shut down and restart after each execution of these locations. Furthermore, this staggering allows for more free space between them. locations, which makes it easier to incorporate new UWB locations (for example, in the event that a new portable identifier connects to the system).

[0052] In this example, the calculated time offset 710 is calculated so that location 221 is executed immediately after location 121, and location 222 immediately after location 123. However, in other examples, this choice could be different. For example, the time offset 710 could be calculated so that locations 221 and 222 are executed before locations 121 and 222 (with a larger offset). Depending on the different constraints of the portable identifiers (e.g., periodicity and period duration), the vehicle system can therefore use different strategies to optimize the concatenation of the respective schedules according to the requirements.

[0053] To implement the offset, an out-of-band message is transmitted by the vehicle system to the selected portable identifier 201 via BLE communication, informing it that a time offset must be applied during the next nth period. n is equal to the current period number plus K periods (for example, K equals the result of dividing 500 ms by the duration of each period, rounded up to the nearest whole number; this 500 ms delay can be negotiated as a configuration element after the BLE connection, for example, for very slow IoT applications, such as the Internet of Things). This allows for the system latency to be taken into account (i.e., the end-to-end transmission and processing time of the BLE message). The time offset can be positive or negative. Its unit can be on the order of a fraction of a millisecond (1 / 3 of a millisecond, for example).An absolute period counter (i.e., for example, a block index as specified in the CCC R3 standard) can be transmitted by the portable identifier in each period.

[0054] Each time a new portable identifier sends a new program (new UWB session), the calculated offset can be less than the duration of a period minus the duration of a UWB location. For example, in the example in the figure, the offset can be as much as + / -176 ms (i.e., 192 ms - 16 ms).

[0055] Whenever clock drift leads to a potential collision, as recommended by the IEEE 802.15.4z standard, the UWB PHY clock can be set to + / -20 ppm (i.e., 2.4 ms / minute). Repeating the calculation and transmission steps every 25 seconds thus allows a reasonable time interval for the time offset to compensate for this clock drift error (for such a repetition frequency, the maximum resulting error is 1 ms).

[0056] In examples, the method may use other considerations for calculating the time offset, such as reconfiguring several programs to to optimize the use of mean time and / or to avoid a recurring error detected due to RF (Radio Frequency) interference or noisy radio environments.

[0057] The scheduling method thus makes it possible to leverage the existing BLE connection to communicate UWB location information with relatively low additional traffic. The method also avoids collisions in the event of simultaneous access and thus increases the quality of service over the range, particularly compared to other methods based on an intertransmission time following a predetermined random probability law, such as those specified in the CCC R3 standard. Indeed, in such methods, the use of this intertransmission time generates temporal diversity and inevitably collisions, leading to suboptimal medium utilization (a lower than optimal number of connected terminals). The method optimizes medium utilization compared to these methods. The method also maximizes the number of simultaneous UWB sessions possible on the same UWB vehicle.The process also allows UWB locations to be grouped together, which reduces the number of sleep / wake transitions (reducing energy consumption).

[0058] Figure 6 illustrates a second example of implementation of the planning process. In this example, three portable identifiers (instead of two in the first example of Figure 5) each send a respective program to the vehicle system (the programs 100, 200 and 500 received from the three identifiers are illustrated in Figure 6).

[0059] The method repeats the calculation and sending of an offset for each of the two identifiers 200 and 500 (their programming is offset relative to that of the first 100). Figure 6 illustrates three scenarios for offsetting these programming that can be implemented by the vehicle system. In the first scenario, the programming 200 of the second portable identifier is offset by an offset of 710, which is the same as in the example in Figure 5. For example, the second portable identifier may have been detected before the third, and may have already been offset before the third sends its programming (in other words, the situation in Figure 6 may follow that of Figure 5). The scheduling method can offset the programming 500 of the third portable identifier by an offset of 720.This offset allows UWB locations with this third portable identifier to be placed immediately after those of the first identifier that are not already followed by a UWB location with the second portable identifier. Indeed, since the frequency of UWB locations with the second and third portable identifiers is half that of the first portable identifier, this alternation is possible. UWB locations that involve the second portable identifier and those that involve the third portable identifier.

[0060] In the second scenario 520, the UWB locations involving the third portable identifier are placed after those involving the second portable identifier. The vehicle system therefore periodically performs three locations in succession, then only one (with the first portable identifier, which has a higher frequency). In the third scenario 530, the same thing happens, but the UWB locations involving the third portable identifier are placed before those involving the first portable identifier (see [Fig. 6]).

[0061] In these three different example scenarios, the method offers improved use of the vehicle's UWB system. Indeed, applying a respective offset to each of the second and third portable identifiers allows the UWB locations of the three portable identifiers to be grouped, thus improving the system's operation. First, optimizing the concatenation of the UWB locations leaves more free space between the groups of UWB locations executed consecutively, which in turn leaves more room to execute additional UWB locations (between groups of two locations for the first scenario, and between the group of three locations and the isolated location for the second and third scenarios). This therefore reduces the risk of collision when a new portable identifier is added.Secondly, this execution allows the vehicle system components involved to switch off and on a reduced number of times (after each group of locations executed consecutively), thus reducing energy consumption and wear (the system can remain powered on to execute the grouped locations together). The process therefore improves system operation.

Claims

Demands

1. A planning method implemented by a vehicle system comprising one or more UWB sensors, the system having recorded a plurality of wearable identifiers, the system and each wearable identifier being configured to communicate using the UWB and BLE communication protocols, the method comprising: • receiving (S10), for each wearable identifier, a respective program comprising a repetition, at a respective frequency, of UWB locations with the vehicle's UWB system; • calculating (S20) a time offset of the respective program of at least one wearable identifier to optimize the concatenation of the UWB locations of the wearable identifiers; and • sending (S30), to at least one wearable identifier, an order to apply the calculated time offset using the BLE communication protocol.

2. A method according to claim 1, wherein the plurality of portable identifiers comprises a first portable identifier and a second portable identifier, the time offset being calculated to temporally conjoin the UWB locations involving the first portable identifier and the UWB locations involving the second portable identifier.

3. A method according to claim 2, wherein the plurality of portable identifiers further comprises at least one third portable identifier, the method comprising calculating a time offset and sending an application command for each of the respective programming of the second and third portable identifiers, the time offset being calculated to temporally conjoin the UWB locations involving the first, second, and third portable identifiers.

4. A method according to any one of claims 1 to 3, wherein the time offset is to be applied from a future period separated from a current period at the time of execution of the method, the spacing between the current period and the future period being equal to a predetermined number of periods.

5. A method according to any one of claims 1 to 4, wherein the respective frequencies with which the UWB locations are repeated each represent a respective period equal to a multiple of a predetermined duration, for example equal to a multiple of 96 milliseconds.

6. A method according to any one of claims 1 to 5, wherein the calculation and sending steps are repeated at least every 25 seconds.

7. A method according to any one of claims 1 to 6, wherein the calculation and sending steps are repeated at each receipt of a new respective programming for a new portable identifier.

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

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

10. Computer program comprising program code instructions for carrying out the method according to any one of claims 1 to 7 and / or according to claim 8, when said program is executed by a processor.

Images