Method for detecting user equipment within a predetermined location zone around a motor vehicle
The method uses Bluetooth® Low Energy Channel Sounding to measure signal powers and phase shifts between vehicle modules to accurately locate user equipment, addressing compatibility and precision issues of existing technologies and enabling efficient vehicle function activation.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
- Filing Date
- 2024-04-11
- Publication Date
- 2026-06-12
AI Technical Summary
Existing methods for locating user equipment around a vehicle, such as using LF, Bluetooth®, and UWB technologies, are either not compatible with modern smartphones, imprecise, or costly and energy-intensive, and fail to address the issue of 'body dumping' where location accuracy varies based on the smartphone's position relative to the user.
A method using Bluetooth® Low Energy Channel Sounding for communication between vehicle modules and user equipment, measuring signal powers and phase shifts between modules to confirm the user's presence within a predefined zone, without requiring UWB technology.
Accurately locates user equipment within a predetermined area regardless of its position on the user, providing simple, reliable, and efficient activation of vehicle functions, while avoiding the complexity and cost of UWB.
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Abstract
Description
Title of the invention: Method for detecting user equipment in a predetermined location zone around a motor vehicle technical field
[0001] The present invention relates to the automotive field and more particularly concerns a method for detecting user equipment in a predetermined location zone around a motor vehicle. Previous technique
[0002] In a motor vehicle, it is known to locate the vehicle's user within a predetermined area around the vehicle, for example, within two meters, in order to activate functions such as unlocking the doors or adjusting the driver's seat. Several solutions based on different technologies exist for this purpose.
[0003] Thus, in a first solution, it is known to use low-frequency (LF) location and radio-frequency communication between the vehicle and a user's badge or key. However, this solution is not usable with current mobile smartphones, which are increasingly used to interact with the vehicle.
[0004] Another solution based on Bluetooth® technology, in particular low energy (Low Energy, or BLE) and its localization component, called "Channel Sounding" (BLE CS) does not prove to be precise enough because the bandwidth is limited to 80 MHz.
[0005] To at least partially overcome these drawbacks, a known solution based on Ultra Wide Band (UWB) technology allows for precise localization using a 500 MHz wide frequency band. However, this solution proves to be complex, expensive, and energy-intensive.
[0006] Furthermore, known solutions do not solve the problem known as "body dumping," which implies that the location can differ greatly depending on whether the smartphone is carried in front of the user or in a back pocket or bag while the user is in the same place, the reflected waves, on the basis of which the distance between the vehicle and the smartphone is calculated, having very different powers.
[0007] A simple, reliable and effective solution that would at least partially remedy these drawbacks would therefore be advantageous. Description of the invention
[0008] To this end, the invention first relates to a method for detecting user equipment within a predetermined location zone around a motor vehicle, said vehicle comprising a plurality of communication modules configured to communicate wirelessly with said user equipment, the peripheral limit of said predetermined location zone being characterized by a predefined distance corresponding to a predefined signal power, called the "reference power," for a signal sent by the user equipment and received by one of the communication modules, said method comprising the steps of:
[0009] - detection and authentication of user equipment,
[0010] - exchange of signals between a first communication module and the equipment user and measurement of the power of said signals, called "first power", and exchange of signals between a second communication module and the user equipment and measurement of the power of said signals, called "second power",
[0011] - if the first power is less than the reference power and if the second power is less than the reference power, then signal exchange between said first communication module and said second communication module, measurement of the power of said signals, called "inter-module power", and measurement of the phase shift between said signals, called "inter-module phase",
[0012] - if the measured inter-module power is less than an inter-module power predetermined and if the measured inter-module phase shift is less than a predetermined inter-module phase shift, then confirmation that the user equipment is in the predetermined localization zone around the vehicle.
[0013] The invention makes it possible to locate user equipment within the localization zone in a simple, reliable, and efficient manner. The method according to the invention does not require energy-intensive and expensive equipment using, for example, UWB technology. Finally, with the method according to the invention and the use of a reference inter-module power and a reference inter-module phase shift, the user equipment is located within the localization zone regardless of its position on the user (in the hand in a free field or in a pocket or bag).
[0014] Preferably, the method further includes a step of activating one or more vehicle functions such as, for example, unlocking the doors or adjusting the driver's seat of the vehicle or a welcome light for the vehicle, etc.
[0015] Preferably, the signals are exchanged between the first communication module, the second communication module and the user equipment on a propagation channel with a width of less than 200 MHz, preferably less than 100 MHz, preferably still in the order of 80 MHz.
[0016] Preferably, the signals are exchanged between the first communication module, the second communication module and the user equipment on a Bluetooth® Low Energy Channel Sounding type communication link.
[0017] In one embodiment, the user equipment is a smartphone configured to communicate over a Bluetooth® Low Energy Channel Sounding type wireless communication link.
[0018] In one embodiment, the user equipment is a key or a badge.
[0019] 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 process as described above.
[0020] The invention also relates to an electronic control unit for a motor vehicle for detecting user equipment within a predetermined location zone around said vehicle, the vehicle comprising a plurality of communication modules configured to communicate wirelessly with said user equipment, the peripheral boundary of said predetermined location zone being characterized by a predefined distance corresponding to a predefined signal power, called the "reference power," for a signal sent by the user equipment and received by one of the communication modules, said electronic control unit being configured to:
[0021] - detect and authenticate user equipment,
[0022] - control the exchange of signals between a first communication module of the vehicle and user equipment and measure the power of said signals, called "first power",
[0023] - control the exchange of signals between a second communication module of the vehicle and user equipment and measure the power of said signals, called "second power",
[0024] - if the first power is less than the reference power and if the second power is less than the reference power, control the exchange of signals between said first communication module and said second communication module, measure the power of said signals, called "inter-module power", and measure the phase shift between said signals, called "inter-module phase",
[0025] - if the measured inter-module power is less than an inter-module power predetermined and if the measured inter-module phase shift is less than a predetermined inter-module phase shift, confirm that the user equipment is in the predetermined location zone around the vehicle.
[0026] The invention also relates to a motor vehicle for the detection of a user equipment in a predetermined localization zone around said vehicle, said vehicle comprising a plurality of communication modules configured to communicate over a wireless communication link with said user equipment, the peripheral limit of said predetermined localization zone being characterized by a predefined distance corresponding to a predefined signal power, called the "reference power," for a signal sent by the user equipment and received by one of the communication modules, said vehicle comprising an electronic control unit as described above.
[0027] The invention also relates to an automotive system comprising a vehicle as described above and user equipment configured to communicate with the vehicle's communication modules over a wireless communication link.
[0028] Preferably, the first communication module, the second communication module and the user equipment are each configured to exchange signals on a propagation channel with a width of less than 200 MHz, preferably less than 100 MHz, and even more preferably in the order of 80 MHz.
[0029] Preferably, the first communication module, the second communication module and the user equipment are each configured to exchange signals on a Bluetooth® Low Energy Channel Sounding type communication link.
[0030] In one embodiment, the user equipment is a smartphone configured to communicate over a Bluetooth® Low Energy Channel Sounding wireless communication link. Brief description of the drawings
[0031] Other features and advantages of the invention will become apparent from the following description. This description is purely illustrative and should be read in conjunction with the accompanying drawings, in which:
[0032] [Fig.1] Fig.1 schematically illustrates one embodiment of the system according to the invention.
[0033] [Fig.2] Fig.2 schematically illustrates one embodiment of the process according to the invention.
[0034] [Fig. 3] Fig. 3 is an example of power as a function of frequency with and without user equipment nearby in the location area.
[0035] [Fig.4] Fig.4 is an example of phase shift as a function of frequency with and without user equipment nearby in the location area. Description of the implementation methods
[0036] Fig. 1 schematically illustrates an example of an automotive system 1 according to the invention.
[0037] The system 1 comprises a motor vehicle 10 and a user equipment 20 worn by a user 2.
[0038] Vehicle 1
[0039] In the example of [Fig.1], the vehicle 10 comprises four communication modules 110 and an electronic control unit 120. The front-left communication module is designated 110-1, the rear-left communication module is designated 110-2, the rear-right communication module is designated 110-3 and the front-right communication module is designated 110-4.
[0040] Each communication module 110 is configured to communicate over a wireless L1 communication link with user equipment 20.
[0041] A predetermined location zone ZL is defined around the vehicle 10. This location zone ZL corresponds to the area in which the user equipment 20 must be located to activate a predetermined function of the vehicle 10 such as, for example, unlocking the doors or activating welcome functions (light, seat settings, etc.).
[0042] The peripheral limit of the predetermined localization zone ZL is characterized by a predefined distance DP corresponding to a predefined signal power, called reference power P_ref ([Fig.2]), for a signal sent by the user equipment 20 and received by one of the communication modules 110.
[0043] Electronic control unit 120
[0044] The electronic control unit 120 is configured to detect and authenticate user equipment 20.
[0045] The electronic control unit 120 is configured to control the exchange of signals between a first communication module 110-1 of the vehicle 10 and the user equipment 20 and to measure the power of said signals, called "first power" PI (Figures 2 to 4).
[0046] The electronic control unit 120 is configured to control the exchange of signals between a second communication module 110-2 of the vehicle 10 and the user equipment 20 and to measure the power of said signals, called "second power" P2 (Figures 2 to 4).
[0047] The electronic control unit 120 is configured to, when the first power PI is less than the reference power P_ref and when the second power P2 is less than the reference power P_ref, control the exchange of signals between said first communication module 110-1 and said second communication module 110-2, to measure the power of said signals, called "inter-module power" PIM (figures 2 to 4), and to measure the phase shift between said signals, called "inter-module phase" DIM (figures 2 to 4).
[0048] The electronic control unit 120 is configured so that, when the power inter measured PIM module power is less than a predetermined inter-module power, referred to as "reference inter-module power PIM_ref" (Figures 2 to 4), and when the measured DIM inter-module phase shift is less than a predetermined inter-module phase shift, referred to as "reference inter-module phase shift DIM_ref" (Figures 2 to 4), confirm that user equipment 20 is in the predetermined ZL location zone around vehicle 10.
[0049] The electronic control unit includes a processor capable of implementing a set of instructions to perform these functions.
[0050] User equipment 20
[0051] The user equipment 20 is configured to communicate with the communication modules 110 of the vehicle 10 over a Bluetooth® Low Energy Channel Sounding type wireless communication link.
[0052] Example of implementation
[0053] As a prerequisite, it is agreed that the reference power has been previously determined. This power corresponds to the signal power when a user test device 20 is placed at the limit of the localization zone ZL, for example exactly two meters from the vehicle 10.
[0054] In a step E0, in the absence of user equipment 20 around or in the vehicle 10, the electronic control unit 120 controls the exchange of signals between the first communication module 110-1 and the second communication module 110-2 and measures (or determines) both the power of said signals and the phase shift between said signals. The power measured in the absence of user equipment 20 is called the "reference inter-module power" and is denoted PIM_ref, and the phase shift measured in the absence of user equipment 20 is called the "reference inter-module phase shift" and is denoted DIM_ref.
[0055] First, in a step E1, the electronic control unit 120 detects and authenticates the user equipment 20. Detection is achieved by periodically emitting beacon signals via the communication modules 110, over a BLE communication link, with a range of up to several tens of meters, and receiving a response from the user equipment 20, without actually locating it. Once detected, a message exchange takes place between the electronic control unit 120, again over a BLE communication link, and at least one of the communication modules 110, to authenticate the user equipment 20. Detection and authentication are preferably performed by the communication modules 110 toward which the user equipment 20 is approaching.Detection and authentication can be performed remotely when user equipment 20 is still outside the predetermined location zone (ZL).
[0056] In this example, with reference to [Fig. 1], user 20 moves towards the door- conductor located between the front-left communication module, called "first module 110-1" and the rear-left communication module, called "second module 110-2".
[0057] In a step E2, the electronic control unit 120 controls the exchange of signals between the first communication module 110-1 and the user equipment 20 and measures the power of said signals, called "first power" PI and the exchange of signals between the second communication module 110-2 and the user equipment 20 and measures the power of said signals, called "second power" P2.
[0058] When the first power PI is less than the reference power P_ref and when the second power P2 is less than the reference power P_ref, reflecting the probable presence of the user equipment 20 in each of the coverage areas Zl, Z2 ([Fig.l]) of the first communication module 110-1 and the second communication module 110-2, i.e. in the location area ZL, the electronic control unit 120 commands the exchange of signals between the first communication module 110-1 and the second communication module 110-2 and measures (or determines) both the power of said signals, called "inter-module power" PIM, and the phase shift between said signals, called "inter-module phase shift" DIM in a step E3.
[0059] When the measured PIM inter-module power is less than the predetermined PIM_ref reference inter-module power and when the measured DIM inter-module phase shift is less than the predetermined DIM_ref reference inter-module phase shift, then the electronic control unit 120 confirms that the user equipment 20 is in the predetermined ZL location zone around the vehicle 10 in a step E4 and then activates one or more FCT functions of the vehicle 10 such as, for example, unlocking the doors, in a step E5.
[0060] Examples of measures
[0061] Figure 3 shows an example of the measured power P (in dBm) as a function of the frequency f (in MHz) over the 80 MHz propagation channel width. The average inter-module power PIM_ref, previously measured over the propagation channel width in the absence of user equipment 20 around the vehicle 10, is approximately -30 dBm. In the presence of user equipment 20, the inter-module power PIM measured over the propagation channel width is approximately -40 dBm. This decrease of -10 dBm indicates the presence of user equipment 20.
[0062] Figure 4 shows an example of the phase shift D measured (in degrees) as a function of the frequency f (in MHz) over the 80 MHz propagation channel width. It appears that the inter-module phase shift DIM measured in the presence of user equipment 20 decreases both before and after the phase reversal that occurs around 38 MHZ, being lower on average than the inter-module phase shift of reference DIM_ref, measured beforehand on the width of the propagation channel in the absence of user equipment 20 around the vehicle 10.
[0063] The invention therefore makes it possible to detect (power) and confirm (phase shift) the presence of a user equipment 20 in the localization zone ZL in a simple, fast, efficient and reliable manner in order to activate one or more functions of the vehicle 10, in particular such as unlocking or welcoming functions.
Claims
Demands
1. A method for detecting user equipment (20) within a predetermined location zone (LZ) around a motor vehicle (10), said vehicle (10) comprising a plurality of communication modules (110) configured to communicate over a wireless communication link (L1) with said user equipment (20), the peripheral boundary of said predetermined location zone (LZ) being characterized by a predefined distance (PD) corresponding to a predefined signal power, called the "reference power" (P_ref), for a signal sent by the user equipment (20) and received by one of the communication modules (110), said method comprising the steps of: - (E1) detection and authentication of the user equipment (20), - (E2) exchange of signals between a first communication module (110-1) and the user equipment (20) and measurement of the power of said signals, called "first power" (P1), and exchange of signals between a second communication module (110-2) and the user equipment (20) and measurement of the power of said signals, called "second power" (P2), - (E3) if the first power (PI) is less than the reference power (P_ref) and if the second power (P2) is less than the reference power (P_ref), exchange of signals between said first communication module (110-1) and said second communication module (110-2), measurement of the power of said signals, said "inter-module power" (IMP), and measurement of the phase shift between said signals, called "inter-module phase" (IMD), - (E4) if the measured inter-module power (PIM) is less than a predetermined inter-module power (PIM_ref) and if the measured inter-module phase shift (DIM) is less than a predetermined inter-module phase shift (DIM_ref), then confirmation that the user equipment (20) is in the predetermined localization zone (ZL) around the vehicle (10).
2. A method according to claim 1, wherein the signals are exchanged between the first communication module (110-1), the second communication module (110-2) and the user equipment (20) on a propagation channel with a width of less than 200 MHz, preferably less than 100 MHz, preferably still in the order of 80 MHz.
3. Method according to the preceding claim, wherein the signals are exchanged between the first communication module (110-1), the second communication module (110-2) and the user equipment (20) over a Bluetooth® Low Energy Channel Sounding type communication link (L1).
4. A method according to any one of the preceding claims, wherein the user equipment (20) is a smartphone configured to communicate over a Bluetooth® Low Energy Channel Sounding wireless communication link (L1).
5. Product computer program 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.
6. Electronic control unit (120) of an automobile (10) for detecting user equipment (20) within a predetermined location zone (LZ) around said vehicle (10), the vehicle (10) comprising a plurality of communication modules (110) configured to communicate over a wireless communication link (L1) with said user equipment (20), the peripheral boundary of said predetermined location zone (LZ) being characterized by a predefined distance (DP) corresponding to a predefined signal power, called "reference power" (P_ref), for a signal sent by the user equipment (20) and received by one of the communication modules (110), said electronic control unit (120) being configured to: - detect and authenticate the user equipment (20),- to control the exchange of signals between a first communication module (110-1) of the vehicle (10) and the user equipment (20) and measure the power of said signals, called "first power" (PD), - to control the exchange of signals between a second communication module (110-2) of the vehicle (10) and the user equipment (20) and measure the power of said signals, called "second power" (P2), - if the first power (PI) is less than the reference power (P_ref) and if the second power (P2) is less than the reference power (P_ref), to control the exchange of signals between said first, communication module (110-1) and said second communication module (110-2), measure the power of said signals, called "inter-module power" (IMP), and measure the phase shift between said signals, called "inter-module phase" (IMD), - if the measured inter-module power (IMP) is less than a predetermined inter-module power (IMP_ref) and if the measured inter-module phase shift (IMD) is less than a predetermined inter-module phase shift (IMD_ref), confirm that the user equipment (20) is in the predetermined localization zone (LZ) around the vehicle (10).
7. Motor vehicle (10) for detecting user equipment (20) in a predetermined location zone (LZ) around said vehicle (10), said vehicle (10) comprising a plurality of communication modules (110) configured to communicate over a wireless communication link (L1) with said user equipment (20), the peripheral boundary of said predetermined location zone (LZ) being characterized by a predefined distance (DP) corresponding to a predefined signal power, called "reference power" (P_ref), for a signal sent by the user equipment (20) and received by one of the communication modules (110), said vehicle (10) comprising an electronic control unit (120) according to the preceding claim.
8. Automotive system (1) comprising a vehicle (10) according to the preceding claim and a user equipment (20) configured to communicate with the communication modules (110) of the vehicle (10) over a wireless communication link (11).
9. System (1) according to the preceding claim, wherein the first communication module (110-1), the second communication module (110-2) and the user equipment (20) are each configured to exchange signals on a propagation channel with a width of less than 200 MHz, preferably less than 100 MHz, preferably still in the order of 80 MHz.
10. System (1) according to any one of claims 8 or 9, wherein the first communication module (110-1), the second communication module (110-2) and the user equipment (20) are each configured to exchange signals over a Bluetooth® Low Energy Channel Sounding communication link (L1).