Method for locating user equipment relative to a motor vehicle
The method iteratively determines user location using ultra-wideband communication and inertial measurement units to address high cost and energy consumption issues, ensuring precise vehicle location with fewer modules.
Patent Information
- Application Number
- FR2023009573
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-09-12
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2043-09-12
AI Technical Summary
Existing vehicle location systems using UWB communication modules face challenges such as high cost, energy consumption, wiring constraints, and prolonged communication times, especially when fewer than three modules can communicate with a smartphone due to obstacles or distance, leading to imprecise location determination.
A method utilizing ultra-wideband communication modules and inertial measurement units to iteratively determine inter-object and inter-step distances, refining probable location areas based on acceleration and orientation data, allowing precise location with fewer modules.
Enables rapid and reliable user equipment location around a vehicle with fewer modules, reducing costs and energy consumption while maintaining accuracy.
Smart Images
Figure 00000015_0000 
Figure 00000015_0001 
Figure 00000016_0000
Abstract
Description
Title of the invention: Method for locating user equipment relative to a motor vehicle Technical field
[0001] The present invention relates to the automotive field and more particularly concerns a method for locating user equipment relative to a motor vehicle. Prior art
[0002] Nowadays, vehicles are known to include an access system that enables the activation of welcome and unlocking functions for the openings of a vehicle. For example, a function may consist of activating a welcome light for the vehicle when the user approaches within ten meters of the vehicle or unlocking the openings when the user is within two meters of the vehicle.
[0003] To this end, the vehicle comprises, in a known manner, communication modules, typically six to eight in number, and an electronic control unit for controlling these modules. Each module comprises an antenna for sending and receiving signals to a device carried by the user such as a key, a dedicated box or a smartphone.
[0004] A widely used technology for communicating between a key or dedicated box and the vehicle is based on radio frequency (RF) and low frequency (LF) signals. With this RF / LF technology, the user's location around the vehicle can be achieved by triangulation using the power of the signals. However, the use of a dedicated device (key or box) is tending to disappear in favor of smartphones.
[0005] Indeed, the advent of smartphones and Bluetooth® and Ultra Wide Band (Ultra Wide Band or UWB) standards are leading equipment manufacturers and constructors to carry out these communications between the vehicle and the user no longer via a key or a dedicated device but directly via the user's smartphone. In particular, smartphones typically do not have an RF / LF interface and communications via Bluetooth® or UWB are faster and the signals are more easily exploitable. In addition, the use of signal power to determine the location of a device worn by the user can be imprecise, due to the attenuation of the signals, in particular by the user's body.
[0006] To solve at least part of this problem, the UWB protocol makes it possible to determine the distance between each communication module and the smartphone by using time-of-flight signals and triangulation.
[0007] However, whatever the method used (power or flight time of the signals), locating the user around the vehicle requires that the smartphone be in communication with at least three communication modules simultaneously in order to be able to locate it precisely by triangulation.
[0008] Solutions exist to try to remedy this drawback at least in part. For example, when only two communication modules are in communication with the smartphone (the others cannot communicate with the smartphone due to an obstacle or their distance), a known solution consists of trying to determine a possible position and an impossible position of the smartphone. However, such a determination is not always possible and it is then not possible to determine with certainty the location of the smartphone. When only one communication module is in communication with the smartphone (the others cannot communicate with the smartphone due to an obstacle or their distance), a known solution consists of using a satellite geolocation module, for example of the GPS type, to be able to approximately determine the location of the smartphone on a circle centered on said communication module.However, this solution cannot be implemented when the smartphone is in an area that does not receive geolocation signals from satellites, for example in a building or in the mountains where there is no coverage.
[0009] An obvious solution to try to remedy at least in part these drawbacks would be to increase the number of UWB communication modules, for example from six or eight to ten or twelve or more. However, this solution has many drawbacks. First of all, each UWB communication module is particularly expensive, for example in the order of a hundred euros, and adding several modules would have a particularly high cost for the vehicle manufacturer, which is generally prohibitive in the automotive industry. Then, each UWB communication module consumes a significant amount of electrical energy, which again presents an increasingly significant drawback as the number of UWB communication modules increases.In addition, each UWB communication module requires wiring to connect it to the vehicle's communication network and the electronic control unit, but there is less and less space in vehicles for this wiring, and the wiring can also pose problems during certifications and even safety problems in the vehicle, especially when they are mounted in the bumpers. Finally, since UWB communication modules communicate sequentially with the smartphone, the more their number increases, the more the time required to communicate with all the modules also increases. However, this time is limited by the standard. CCC at 96 ms and the use of, for example, twelve UWB communication modules would lead to a duration of around one and a half seconds, which is prohibitive.
[0010] A simple, reliable and effective solution making it possible to at least partially overcome these drawbacks would therefore be advantageous, in particular a solution which would make it possible to limit the number of UWB communication modules. Statement of the invention
[0011] To this end, the invention firstly relates to a method for locating user equipment relative to a motor vehicle, said vehicle comprising an electronic control unit and a plurality of ultra-wideband communication modules, said user equipment, worn by a user, comprising an inertial measurement unit configured to provide acceleration and orientation data of said user equipment and an ultra-wideband communication module, configured to communicate with each of the ultra-wideband communication modules of the vehicle, said method comprising the steps carried out iteratively when the user is in motion of:
[0012] - exchange of ultra-wideband signals between at least one communication module vehicle ultra-wideband communication module and user equipment ultra-wideband communication module,
[0013] - determination of the so-called “inter-object” distance between said at least one module of ultra-wideband communication of the vehicle and user equipment based on the time of flight of the exchanged signals,
[0014] - measurement of acceleration and orientation values of user equipment,
[0015] - calculation of the so-called “inter-step” distance taken by the user between two steps consecutive from the measured acceleration and orientation values,
[0016] - cross-checking of the determined inter-object distance and the inter-object distance not calculated in order to determine at least one probable location area of the user equipment,
[0017] the iterations ending when a single probable location area of the user equipment whose surface area is less than a predefined surface area has been determined, said single probable location area then corresponding to the location of the user equipment around the vehicle.
[0018] The method according to the invention makes it possible to locate the user of the vehicle precisely and quickly when he approaches said vehicle. Indeed, it only takes a few steps from the user when approaching the vehicle to determine, in as many iterations of the method, a series of probable location zones of the user equipment (and therefore of the user) which are refined until a single area of sufficiently small surface area is obtained to determine the exact location of the equipment user.
[0019] According to one aspect of the invention, the cross-checking comprises determining the probable positions of the user equipment at the inter-object distance and at the inter-step distance.
[0020] In one embodiment, the number of iterations is at least four, for example five or six.
[0021] The invention also relates to a computer program product characterized in that it comprises a set of program code instructions which, when executed by one or more processors, configure the processor(s) to implement a method as presented previously.
[0022] The invention also relates to user equipment configured to implement the method as presented previously, said user equipment being further configured to send the location, determined following the iterations, to the vehicle.
[0023] The invention also relates to an electronic control unit for a motor vehicle, said electronic control unit being configured to:
[0024] - determine the so-called “inter-object” distance between at least one communication module ultra-wideband communication of the vehicle and user equipment carried by a user from the time of flight of ultra-wideband signals exchanged between said at least one ultra-wideband communication module of the vehicle and an ultra-wideband communication module of said user equipment,
[0025] - receive acceleration and orientation values sent by the equipment user,
[0026] - calculate the so-called “inter-step” distance taken by the user between two steps consecutive from the measured acceleration and orientation values,
[0027] - cross-reference the determined inter-object distance and the calculated inter-step distance in order to determine at least one probable location area of the user equipment,
[0028] - determine the location of the user equipment around the vehicle when a single probable location area of the user equipment with an area less than a predefined area has been determined.
[0029] According to one aspect of the invention, the electronic control unit is configured, upon cross-referencing, to determine the probable positions of the user equipment at the inter-object distance and at the inter-step distance.
[0030] In one embodiment, the electronic control unit is configured to perform at least four iterations of the method according to any one of claims 1 to 3, preferably five or six iterations.
[0031] The invention also relates to a motor vehicle comprising a plurality of ultra-wideband communication modules and an electronic control unit. as presented above.
[0032] The invention also relates to a communication system comprising a vehicle and user equipment, said vehicle comprising an electronic control unit and a plurality of ultra-wideband communication modules, said user equipment comprising an inertial measurement unit configured to provide acceleration and orientation data of said user equipment and an ultra-wideband communication module, configured to communicate with each of the ultra-wideband communication modules of the vehicle, the vehicle and the user equipment being configured to implement the method as described above, the steps being distributed in any way between said vehicle and said user equipment, with the exception of the step of measuring the acceleration and orientation values of the user equipment which is in all cases carried out by the user equipment.
[0033] The invention also relates to a communication system comprising a vehicle as presented previously and user equipment comprising an inertial measurement unit configured to provide acceleration and orientation data of said user equipment and an ultra-wideband communication module, configured to communicate with each of the ultra-wideband communication modules of the vehicle. Brief description of the drawings
[0034] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This is purely illustrative and must be read in conjunction with the appended drawings in which:
[0035] [Fig-1] [Fig.l] schematically illustrates one embodiment of the system according to the invention.
[0036] [Fig.2] [Fig.2] schematically illustrates the user equipment of the system of [Fig.l],
[0037] [Fig.3] [Fig.3] schematically illustrates a first embodiment of the method according to the invention.
[0038] [Fig.4] [Fig.4] schematically illustrates a second embodiment of the method according to the invention.
[0039] [Fig.5] [Fig.5] illustrates an example of implementation of the method according to the invention during a first iteration.
[0040] [Fig.6] [Fig.6] illustrates an example of implementation of the method according to the invention during a second iteration.
[0041] [Fig.7] [Fig.7] illustrates an example of implementation of the method according to the invention during a third iteration.
[0042] [Fig.8] [Fig.8] illustrates an example of implementation of the method according to the invention during a fourth iteration.
[0043] [Fig.9] [Fig.9] illustrates an example of implementation of the method according to the invention during a fifth iteration.
[0044] [Fig. 10] [Fig. 10] illustrates an example of implementation of the method according to the invention during a sixth iteration.
[0045] [Fig. 11] [Fig. 11] illustrates an example of implementation of the method according to the invention during a seventh iteration.
[0046] [Fig. 12] [Fig. 12] illustrates an example of implementation of the method according to the invention during an eighth iteration.
[0047] [Fig. 13] [Fig. 13] illustrates an example of implementation of the method according to the invention during a ninth iteration.
[0048] [Fig. 14] [Fig. 14] illustrates an example of implementation of the method according to the invention during a tenth iteration. Description of the embodiments
[0049] [Fig.l] illustrates an example of system 1 according to the invention.
[0050] The system 1 comprises a vehicle 10 and user equipment 20 carried by a user 21.
[0051] The vehicle 10 comprises an electronic control unit 110 and a plurality of ultra-wideband communication modules 120.
[0052] With reference to [Fig.2], the user equipment 20 comprises an inertial measurement unit 210, configured to provide acceleration and orientation data of said user equipment 20, and an ultra-wideband communication module 220, configured to communicate with each of the ultra-wideband communication modules 120 of the vehicle 10.
[0053] First embodiment
[0054] In this first embodiment, the electronic control unit 110 is configured to determine the so-called “inter-object” distance between at least one of the ultra-wideband communication modules 120 of the vehicle 10 and the user equipment 20 from the time of flight of ultra-wideband signals exchanged between said at least one ultra-wideband communication module 120 of the vehicle 10 and the ultra-wideband communication module 220 of the user equipment 20.
[0055] In this first embodiment, the user equipment 20 is configured to send the measured acceleration and orientation values to the electronic control unit 110 and the electronic control unit 110 is configured to receive said acceleration and orientation values sent by the user equipment 10.
[0056] In this first embodiment, the electronic control unit 110 is configured to calculate the so-called “inter-step” distance taken by the user 21 between two consecutive steps from the acceleration and orientation values received.
[0057] In this first embodiment, the electronic control unit 110 is configured to cross-reference the determined inter-object distance and the calculated inter-step distance in order to determine at least one probable location zone of the user equipment 20. To this end, the electronic control unit 110 is configured, during the cross-reference, to determine the probable positions of the user equipment 10 at the inter-object distance and at the inter-step distance.
[0058] The electronic control unit is configured to carry out several iterations of the preceding determinations and calculations, as many times as the number of steps of the user 21, in order to be able to determine the location of said user 21, preferably at least four iterations, more preferably five or six iterations.
[0059] In this first embodiment, the electronic control unit 110 is configured to determine the location of the user equipment 20 around the vehicle 10 when a single probable location zone of the user equipment 10 whose surface area is less than a predefined surface area is determined.
[0060] The electronic control unit 110 comprises a processor capable of implementing a set of instructions making it possible to carry out these functions.
[0061] Second embodiment
[0062] In a second embodiment, the user equipment 20 is configured to exchange ultra-wideband signals with at least one of the ultra-wideband communication modules 120 of the vehicle 10 via the ultra-wideband communication module 220.
[0063] In this second embodiment, the user equipment 20 is configured to receive the so-called “inter-object” distance between said at least one ultra-wideband communication module 120 of the vehicle 10 and the user equipment 20 calculated by the electronic control unit 110 from the time of flight of the exchanged signals.
[0064] In this second embodiment, the user equipment 20 is configured to measure acceleration and orientation values of the user equipment when the user 21 moves with the user equipment 20.
[0065] In this second embodiment, the user equipment 20 is configured to calculate the so-called “inter-step” distance taken by the user 21 between two consecutive steps from the measured acceleration and orientation values.
[0066] In this second embodiment, the user equipment 20 is configured to cross-reference the determined inter-object distance and the calculated inter-step distance in order to determine at least one probable location zone of the user equipment. 20.
[0067] In this second embodiment, the user equipment 20 is configured to carry out the iterations of the preceding determinations and calculations, as many times as the number of steps of the user 21, in order to be able to determine the location of said user 21, preferably at least four iterations, more preferably five or six iterations.
[0068] The iterations end when a single probable location area of the user equipment whose surface area is less than a predefined surface area has been determined by the user equipment 20, said single probable location area then corresponding to the location of the user equipment 20 around the vehicle 10.
[0069] In this second embodiment, the user equipment 20 is configured to send the location, determined following the iterations, to the vehicle 10.
[0070] Examples of implementation
[0071] First example of implementation
[0072] This first example implements the first embodiment and is described with reference to [Fig.3].
[0073] In this example, the user approaches a corner of the vehicle 10 such that it is visible, i.e. such that it can only communicate, with one of the ultra-wideband communication modules 120 of the vehicle 10. The method begins with a first iteration when the user equipment 20 is detected by the ultra-wideband communication module 120 of the vehicle 10 in visibility.
[0074] The ultra-wideband communication module 220 of the user equipment 20 therefore firstly exchanges ultra-wideband signals with said single ultra-wideband communication module 120 of the vehicle 10 which it has in view in a step EL
[0075] The electronic control unit 110 then determines in a step E2, for example periodically, the inter-object distance DIO between the ultra-wideband communication module 120 of the vehicle 10 in visibility and the user equipment 20 from the time of flight of the exchanged signals and then sends the determined inter-object distance to the user equipment 20 via the ultra-wideband communication module 120 of the vehicle 10 in visibility in a step E3.
[0076] The inertial measurement unit 210 of the user equipment 20 measures in a step E4 the acceleration and orientation values of the user equipment 20 when the user 21 moves, then sends in a step E5 the measured values to the electronic control unit 110 via the ultra-wideband communication module 120 of the vehicle 10 in visibility.
[0077] The electronic control unit 110 then calculates in a step E6 the inter distance DIP step carried out by the user 21 between two consecutive steps from the received acceleration and orientation values, then cross-references in a step E7 the determined inter-object distance DIO and the calculated inter-step distance DIP in order to determine at least one probable location zone ZLP of the user equipment 20.
[0078] Steps E1 to E7 are repeated until the electronic control unit 110 determines a single probable location zone ZLP whose surface area is less than a predefined surface area and which corresponds to the location of the user equipment 20 around the vehicle 10.
[0079] Second example of implementation
[0080] This second example implements the second embodiment and is described with reference to [Fig.4].
[0081] In this example, as in the previous example, the user approaches a corner of the vehicle 10 so that it is visible, i.e. so that it can only communicate, with one of the ultra-wideband communication modules 120 of the vehicle 10. The method begins with a first iteration when the user equipment 20 is detected by the ultra-wideband communication module 120 of the vehicle 10 in visibility.
[0082] The ultra-wideband communication module 220 of the user equipment 20 therefore firstly exchanges ultra-wideband signals with said single ultra-wideband communication module 120 of the vehicle 10 which it has in view in a step FL
[0083] The electronic control unit 110 then determines in a step F2, for example periodically, the inter-object distance DIO between the ultra-wideband communication module 120 of the vehicle 10 in visibility and the user equipment 20 from the time of flight of the exchanged signals and then sends the determined inter-object distance DIO to the user equipment 20 via the ultra-wideband communication module 120 of the vehicle 10 in visibility in a step F3. Alternatively, the user equipment 20 can determine in step F2, for example periodically, the inter-object distance and there is no sending step F3.
[0084] Then, the inertial measurement unit 210 of the user equipment 20 measures in a step F4 the acceleration and orientation values of the user equipment 20 when the user 21 moves.
[0085] The user equipment 20 then calculates in a step F5 the inter-step distance DIP carried out by the user 21 between two consecutive steps from the received acceleration and orientation values, then cross-references in a step F6 the determined inter-object distance DIO and the calculated inter-step distance DIP in order to determine at least one probable location zone ZLP of the user equipment 20.
[0086] Steps F1 to F6 are repeated until the user equipment 20 determines a single probable location zone ZLP whose surface area is less than a predefined surface area and which corresponds to the location of said user equipment 20 around the vehicle 10.
[0087] It should be noted that the steps of the method according to the invention, with the exception of the measurements of acceleration and orientation values of the user equipment 20, can be implemented indifferently by the electronic control unit 10 or the user equipment 20. Thus, the other embodiments whose steps are implemented partly by the electronic control unit 110 and partly by the user equipment 20 and which differ from the two examples given above are also covered by the present invention.
[0088] Simulation example
[0089] Figures 5 to 14 are a representation in the form of a two-dimensional geographical map seen from above of an example of determining the position of the user equipment 20 during the first ten iterations of the method according to the invention. The dimensions of the map are in meters.
[0090] The ultra-wideband communication module 120 of the vehicle 10 is represented by a white star. The user equipment 20 is represented by a disc. The trajectory of the user equipment is represented by the lines followed by the disc. The probable location zones ZLP are represented in light gray. The background of the map (areas other than the probable location zones ZLP) are represented in black.
[0091] During the first iteration ([Fig.5]), it is established that the user equipment 20 is located at a given distance from the ultra-wideband communication module 120. Its probable location zone ZLP is therefore in the form of a circle whose thickness represents the measurement tolerance (uncertainty on the measured distance).
[0092] At the second iteration ([Fig.6]), user 21 having taken a step and knowing therefore its step length and the orientation of the user equipment 20 (direction of movement), the method makes it possible to reduce the probable location zone ZLP to a distinct area which corresponds to an arc of the circle.
[0093] The third iteration ([Fig.7]) makes it possible, after an additional step by the user 21, to reduce the probable location zone ZLP to two distinct areas which correspond to two portions of the arc of the circle whose total surface area is less than the surface area of the probable location zone ZLP determined in the previous iteration.
[0094] The fourth iteration ([Fig.8]) allows, after an additional step by the user 21, to further reduce the probable location zone ZLP, still to two distinct areas in this example, which correspond to two portions of the arc of the circle whose total surface area is less than the surface area of the probable location zone ZLP determined in the previous iteration.
[0095] The fifth iteration ([Fig.9]) makes it possible, after an additional step by the user 21 and a change of direction on his part, to reduce the probable location zone ZLP to a single probable location zone ZLP whose surface area is here substantially equal to that of one of the areas obtained in the previous iteration and less than the predefined surface area which corresponds to the location of said user equipment 20 around the vehicle 10.
[0096] The sixth, seventh, eighth, ninth and tenth iterations (figures 10 to 14) make it possible, after an additional step by the user 21 at each iteration, to further refine the surface of the probable location zone ZLP to improve the accuracy of the location of the user equipment 20 along its trajectory.
[0097] The invention therefore makes it possible to determine in a rapid, reliable and efficient manner the position of the user equipment 20 relative to the vehicle 10, i.e. its location around the vehicle 10, by using both the trajectory followed by the user equipment 20 and the distance separating the vehicle 10 from the user equipment 20.
Claims
Claims
1. A method for locating user equipment (20) relative to a motor vehicle (10), said vehicle (10) comprising an electronic control unit (110) and a plurality of ultra-wideband communication modules (120), said user equipment (20), carried by a user (21), comprising an inertial measurement unit (210) configured to provide acceleration and orientation data of said user equipment (20) and an ultra-wideband communication module (220), configured to communicate with each of the ultra-wideband communication modules (120) of the vehicle (10), said method comprising the steps performed iteratively when the user (21) is in motion of: - exchanging (El, Fl) ultra-wideband signals between at least one ultra-wideband communication module (120) of the vehicle (10) and the ultra-wideband communication module (220) of the user equipment (20),- determining (E2, F2) the so-called "inter-object" distance (DIO) between said at least one ultra-wideband communication module (120) of the vehicle (10) and the user equipment (20) from the time of flight of the exchanged signals, - measuring (E4, F4) the acceleration and orientation values of the user equipment (20), - calculating (E6, F5) the so-called "inter-step" distance (DIP) carried out by the user (21) between two consecutive steps from the measured acceleration and orientation values, - cross-referencing (E7, F6) the determined inter-object distance (DIO) and the calculated inter-step distance (DIP) in order to determine at least one probable location zone (ZLP) of the user equipment (20), the iterations ending when a single probable location zone (ZLP) of the user equipment (20) whose surface is less than a predefined area has been determined,said single probable location zone (PLZ) then corresponding to the location of the user equipment (20) around the vehicle (20).,
2. The method of claim 1, wherein the cross-checking comprises determining the probable positions of the user equipment (20) at the inter-object distance (IOD) and the inter-step distance (IPD).
3. A method according to any preceding claim, in in which the number of iterations is at least four, for example five or six.
4. A computer program product characterized in that it comprises a set of program code instructions which, when executed by one or more processors, configure the processor(s) to implement a method according to any one of the preceding claims.
5. User equipment (20) configured to implement the method according to any one of claims 1 to 3, said user equipment (20) being further configured to send the location, determined following the iterations, to the vehicle (10).
6. Electronic control unit (110) for a motor vehicle (10), said electronic control unit (110) being configured to: - determine the so-called "inter-object" distance (DIO) between at least one ultra-wideband communication module (120) of the vehicle (10) and a user equipment (20) carried by a user (21) from the time of flight of ultra-wideband signals exchanged between said at least one ultra-wideband communication module (120) of the vehicle (10) and an ultra-wideband communication module (220) of said user equipment (20), - receive acceleration and orientation values sent by the user equipment (20), - calculate the so-called "inter-step" distance (DIP) taken by the user (21) between two consecutive steps from the measured acceleration and orientation values,- cross-referencing the determined inter-object distance (IOD) and the calculated inter-step distance (IPD) in order to determine at least one probable location zone (PLZ) of the user equipment (20), - determining the location of the user equipment (20) around the vehicle (10) when a single probable location zone (PLZ) whose surface area is less than a predefined surface area has been determined.,
7. Electronic control unit (110) according to the preceding claim, said electronic control unit (110) being configured, upon cross-referencing, to determine the probable positions of the user equipment (20) at the inter-object distance (DIO) and at the inter-step distance (DIP).
8. Electronic control unit (110) according to the preceding claim, said electronic control unit (110) being configured to perform at least four iterations of the method according to any one of claims 1 to 3, preferably five or six iterations.
9. A motor vehicle (10) comprising a plurality of ultra-wideband communication modules (120) and an electronic control unit (110) according to any one of claims 6 to 8.
10. Communication system (1) comprising a vehicle (10) according to the preceding claim and user equipment (20) comprising an inertial measurement unit (210) configured to provide acceleration and orientation data of said user equipment (20) and an ultra-wideband communication module (220), configured to communicate with each of the ultra-wideband communication modules (120) of the vehicle (10).