FR3129559A1 - Method and device for controlling a wireless charging system for a wireless communication device on board a vehicle - Google Patents

Abstract

The present invention relates to a method and a device for controlling a wireless charging system (101) on board a vehicle (10). The vehicle (10) also has a hands-free access and start system, known as the ADML system. Controlling the wireless charging system includes determining by the vehicle (10) a current speed of the vehicle (10). The charging power of the wireless charging system is controlled as a function of speed, the charging power being reduced from a first power level to a second power level when the current speed of the vehicle is below a determined threshold speed . Figure for abstract: Figure 1

Description

Method and device for controlling a wireless charging system for a wireless communication device on board a vehicle

The present invention relates to methods and devices for controlling a wireless charging system for a wireless communication device on board a vehicle, in particular a motor vehicle. The present invention also relates to a method and a device for controlling the charging power of a wireless charging system for a wireless communication device on board a vehicle.

Technology background

Some contemporary vehicles embed a technology known as the Hands-Free Access and Start system (ADML, or PEPS in English for “Passive Entry Passive Start” or PKES for “Passive Keyless Entry and Start”). It is thus possible to gain access to the vehicle (unlocking and locking of the doors) and/or to start a vehicle without having to insert the key in the ignition. The ADML system is associated with a hands-free key which exchanges information in the form of radiofrequency signals with the vehicle to lock or unlock the vehicle but also to start it without having to insert a key in the ignition.

However, some hands-free entry and start systems have security vulnerabilities used by thieves. The vulnerability of these systems is illustrated by a method of fraudulent vehicle access known as a relay attack, which allows a thief to open or close a vehicle using a device relaying the identification information contained in the hands-free key, even if the latter is far enough from the vehicle not to authorize opening and starting. The vulnerability of ADML systems to relay attacks is for example described in the document entitled “Relay Attacks on Passive Keyless Entry and Start Systems in Modern Cars” by Aurélien Francillon, Boris Danev and Srdjan Capkun, published in 2011 in “Computer Science, Engineering », DOI: 10.3929/ETHZ-A-006708714.

To reduce the risks associated with these faults, it is known to equip the hands-free key with a motion detector. When the hands-free key is outside the vehicle, the low-frequency reception of the hands-free key is disabled when no movement of the key is detected, reducing the risk of a relay attack. When the hands-free key is detected inside the vehicle, the low frequency reception of the hands-free key remains activated, whether the key is in motion or not.

Some of these vehicles also have a wireless charging system on board to charge a mobile communication device such as a mobile phone by induction.

One of the problems associated with combining these two systems in the same vehicle, namely the ADML system and the wireless charging system (or inductive charging system) is that they use very similar, or even identical, frequency bands. which generates problems of electromagnetic compatibility (EMC) between these two systems.

For example, when the wireless charging system is active, the ADML system may be disrupted and have difficulty detecting or recognizing the hands-free key.

Conversely, when the vehicle sends an authentication request to the hands-free key, in particular when the vehicle is stationary (for example at a stop sign or at a red light), the transmission of the signal comprising the request may disturb the wireless charging system. The interference generated by the transmission of the signal is likely to interrupt the inductive charging of the mobile communication device, such an interruption being detected by the mobile communication device which consequently generates an alert (for example a beep and/or the display of a message on the screen of the mobile communication device).

EMC problems thus cause malfunctions of the ADML system and/or the wireless charging system when the latter operate concomitantly.

Summary of the present invention

An object of the present invention is to solve at least one of the problems of the technological background described above.

Another object of the present invention is to improve the electromagnetic compatibility between the ADML system and the wireless charging system of a vehicle.

According to a first aspect, the present invention relates to a method for controlling a wireless charging system for a wireless communication device, the wireless charging system being embedded in a vehicle, the vehicle further comprising an access system and hands-free starting, called ADML system, the method being implemented by the vehicle when an engine of the vehicle is running, the method comprising the following steps:

- determination of a current speed of the vehicle;

- control of a charging power of the wireless charging system as a function of the speed, the charging power being reduced from a first power level to a second power level when the current speed is lower than a determined threshold speed .

According to a variant, the charging power is reduced from the first power level to the second power level when the current speed is lower than the determined threshold speed for a duration greater than a determined threshold duration.

According to another variant, the determined threshold duration is equal to 10 seconds.

According to yet another variant, the second power level is less than or equal to 2 W.

According to an additional variant, the first power level is greater than or equal to 15 W.

According to an additional variant, the threshold speed is equal to 5 km/h.

According to another variant, the method further comprises a step of further comprising a step of displaying information representative of the load power.

According to a second aspect, the present invention relates to a device for controlling a wireless charging system for a wireless communication device, the device comprising a memory associated with a processor configured for the implementation of the steps of the method according to the first aspect of the present invention.

According to a third aspect, the present invention relates to a vehicle, for example of the automobile type, comprising a device as described above according to the second aspect of the present invention.

According to a fourth aspect, the present invention relates to a computer program which comprises instructions adapted for the execution of the steps of the method according to the first aspect of the present invention, this in particular when the computer program is executed by at least one processor.

Such a computer program can use any programming language, and be in the form of source code, object code, or intermediate code between source code and object code, such as in a partially compiled form, or in any other desirable form.

According to a fifth aspect, the present invention relates to a computer-readable recording medium on which is recorded a computer program comprising instructions for the execution of the steps of the method according to the first aspect of the present invention.

On the one hand, the recording medium can be any entity or device capable of storing the program. For example, the medium may comprise a storage means, such as a ROM memory, a CD-ROM or a ROM memory of the microelectronic circuit type, or even a magnetic recording means or a hard disk.

On the other hand, this recording medium can also be a transmissible medium such as an electrical or optical signal, such a signal being able to be conveyed via an electrical or optical cable, by conventional or hertzian radio or by self-directed laser beam or by other ways. The computer program according to the present invention can in particular be downloaded from an Internet-type network.

Alternatively, the recording medium may be an integrated circuit in which the computer program is incorporated, the integrated circuit being adapted to execute or to be used in the execution of the method in question.

Brief description of figures

Other characteristics and advantages of the present invention will emerge from the description of the particular and non-limiting examples of embodiments of the present invention below, with reference to the appended figures 1 to 3, in which:

schematically illustrates a vehicle on board a wireless charging system for a mobile communication device, according to a particular and non-limiting embodiment of the present invention;

schematically illustrates a device configured to control the wireless charging system of the , according to a particular and non-limiting embodiment of the present invention;

illustrates a flowchart of the different steps of a method for controlling the wireless charging system of the , according to a particular and non-limiting embodiment of the present invention.

Description of the examples of realization

A method and a device for controlling a wireless charging system on board a vehicle will now be described in the following with reference to FIGS. 1 to 3. The same elements are identified with the same reference signs throughout. along the following description.

According to a particular and non-limiting example of embodiment of the present invention, a vehicle embeds a wireless charging system configured to recharge the battery of a wireless communication device (for example a smart telephone (from the English "smartphone") ) or a connected object such as a connected watch) as well as a hands-free access and start system, known as the ADML system. The control of the wireless charging system includes the determination by the vehicle, when the engine of the latter is running or operating, of a current speed of the vehicle. The charging power of the wireless charging system is controlled as a function of speed, the charging power being reduced from a first power level (e.g. equal to 15 Watts or more) to a second power level (e.g. equal to 1.5 or 2 Watts) when the current speed of the vehicle is lower than a determined threshold speed, for example lower than 5 km/h.

Reducing the charging power allows the operating frequency of the wireless charging system to be lowered (for example to lower the frequency from 125 kHz to 110 kHz), which makes it possible to leave the frequency band used by the ADML system during exchanges between the vehicle and the hands-free key, such a frequency band being for example between 120 and 135 kHz.

The risk of interference between the two systems is thus drastically reduced, which avoids service interruptions of the ADML system and/or the charging system of the communication device. The electromagnetic compatibility (EMC) between these two systems is thus improved.

schematically illustrates a vehicle 10 carrying a wireless charging system for a mobile communication device, according to a particular and non-limiting embodiment of the present invention.

There more particularly illustrates a part of the passenger compartment of the vehicle 10, in particular of the front part of the passenger compartment of the vehicle 10 comprising in particular the steering wheel, the dashboard and the front seats.

The vehicle 10 corresponds for example to a vehicle with a combustion engine, with electric motor(s) or else a hybrid vehicle with a combustion engine and one or more electric motors. The vehicle 10 thus corresponds for example to a land vehicle, for example an automobile, a truck, a coach.

The vehicle 10 advantageously embeds a wireless charging system 101 (also called an induction charging system). Such a system 101 corresponds to a station configured to receive the mobile communication device to be charged. To this end, the system 101 comprises a flat surface (sometimes called an interface surface) designed to receive a mobile communication device of the smart telephone type placed flat on this flat surface. The system also includes a transmitter (also called a transmitter) connected to a source of electrical energy, for example the vehicle battery 10. The transmitter is positioned under the flat surface receiving the mobile communication device. The transmitter advantageously comprises a coil generating an electromagnetic field which transports the energy to the receiver (for example integrated in a mobile communication device of the smart phone type) positioned on the flat surface at a distance from the transmitter which is for example less than 40 mm for the transfer of energy from the transmitter to the receiver to be effective. The transmitter coil is arranged in a series resonant circuit, of the LC circuit or RLC circuit type, operating at a determined resonant frequency.

Such a transmitter is known to those skilled in the art, as is the wireless energy transfer technology between a transmitter and a receiver. Wireless energy transfer technology is based on so-called inductive coupling technology or on so-called magnetic resonance technology.

The energy transfer implemented between the wireless charging system 101 and the mobile communication device positioned above this system is for example in accordance with the Qi® standard published by the WPC (from the English “Wireless Power Consortium” or in French “Wireless Power Consortium”), for example in the document entitled “The Qi Wireless Power Transfer System / Power Class 0 Specification”, version 1.2.4 of February 2018.

According to one variant, the energy transfer complies with the "Rezence" standard developed and published by the A4WP (from the English "Alliance for Wireless Power" or in French "alliance for wireless power"), which in 2015 became Airfuel Alliance®.

The system 101 is advantageously configured to operate according to different power profiles, for example a first power profile with a power greater than or equal to 15 W (Watts) and a second power profile with a power less than or equal to 5 W. The first power profile is known as "Extended Power Profile" in the Qi® standard and the second power profile is known as "Baseline Power Profile" (or “Base power profile” in French) in the same Qi® standard.

The operating (or resonant) frequency of the System 101 transmitter depends on the power profile implemented. For example, the operating frequency is fixed and equal to 127.7 kHz for the first power profile (greater than or equal to 15 W) that the operating frequency is included in the frequency band between 110 kHz and 205 KHz for the second power profile (less than or equal to 5 W).

The vehicle 10 also advantageously embeds an ADML system. The in-vehicle ADML system 10 is configured to communicate data with a hands-free key via one or more wireless links. For this purpose, the ADML system comprises for example one or more computers associated with one or more antennas, for example one or more antennas for transmitting data to the hands-free key and for receiving data transmitted by this hands-free key. The antenna or antennas of the ADML system embedded in the vehicle 10 are for example controlled by a telematics control unit, called TCU (from the English “Telematic Control Unit”), itself connected to the computer or computers of the ADML embedded system of the vehicle 10. The antenna(s), the unit TCU, the computer(s) of the ADML system and the computer(s) controlling the wireless charging system 101 form, for example, a multiplexed architecture for carrying out various services useful for the good operation of the vehicle and to assist the driver and/or the passengers of the vehicle in controlling the vehicle 10, for example by authorizing the unlocking and/or the starting of the vehicle from identifiers stored in the hands-free key and/or by controlling the load of a mobile communication device positioned on the flat surface of the system 101 provided for this purpose. The computer or computers and the TCU communicate and exchange data with each other via one or more computer buses, for example a communication bus of the CAN data bus type (from the English “Controller Area Network”). or in French "Network of controllers"), CAN FD (from English "Controller Area Network Flexible Data-Rate" or in French "Network of controllers with flexible data rate"), FlexRay (according to the ISO 17458 standard) or Ethernet (according to ISO/IEC 802-3 standard).

The ADML system of the vehicle 10 is configured to implement a process for determining the location of the hands-free key inside the vehicle 10. Such a process is known to those skilled in the art and based on the use of an LF low-frequency channel. Such a process is for example described in the document entitled “Relay Attacks on Passive Keyless Entry and Start Systems in Modern Cars” and identified in the technological background. The low-frequency channel uses for example the frequency band between 120 kHz and 135 kHz, that is to say a frequency band comprising the operating frequency (for example equal to 127.7 kHz or 125 kHz) used in the first power profile (greater than or equal to 15 W) by the wireless charging system 101.

A process for controlling the wireless charging system 101 of the vehicle 10 is advantageously implemented by a device on board the vehicle 10, for example a computer (via one or more processors of this computer) of the on-board system of the vehicle.

In a first operation, the engine of the vehicle 10 is started or started, for example by pressing a button provided for this purpose in the passenger compartment of the vehicle 10.

Pressing the start button for example puts the system 101 on, which starts for example with the second power profile, for example for a determined period (for example equal to 5 or 10 seconds) before automatically switching to the first power profile. The duration during which the system 101 starts with the second power profile is for example calibrated or configured to allow the ADML system to exchange data with the key, for example for the location of the key and/or the identification of information contained in the key to authorize the start.

According to a variant, the starting of the system 101 occurs only once the engine has started, that is to say once the ADML system has successfully authenticated the information contained in the key. According to this variant, the system 101 starts directly with the first power profile.

In a second operation, the computer determines a current speed of the vehicle 10. This current speed is for example determined from data received from another computer of the on-board system of the vehicle 10, for example the computer controlling one or more speed sensors (such as an odometer for example) on board the vehicle 10. According to a variant, the computer receives the data representative of the speed of the vehicle 10 directly from the speed sensor(s).

In a third operation, the speed determined in the first operation is compared with a determined threshold speed. This determined threshold speed is for example equal to 2, 3, 5 or 7 km/h. According to a variant, a set of consecutive speeds (forming a speed profile over a time interval equal to for example a few seconds) is compared with this threshold speed.

In a fourth operation, the charging power of the wireless charging system 101 is controlled according to the result of the comparison of the second operation, that is to say according to the speed determined in the first operation.

Thus, the charging power is reduced from a first power level (for example 15 W) to a second power level (less than 5 W, for example equal to 1.5, 2, 3 or 4 W) when the determined speed at the first operation goes below the determined threshold speed, that is to say when the vehicle 10 slows down for example to stop at a stop sign, at a red light, to let a pedestrian pass, etc.

The default operating power of the wireless charging system is for example equal to the first power, corresponding to the operation of the system 101 according to the first power profile. The operating frequency of the transmitter of system 101 is then for example equal to 125 kHz or 127.7 kHz.

When the speed of the vehicle falls below the speed threshold value (for example 5 km/h), the system switches to operation in accordance with the second power profile. The system then operates at a second power (for example 2 W), for example configured and stored in the memory of the computer controlling the wireless charging system 101. The operating frequency of the transmitter is then advantageously lower than the lower limit of the frequency band used by the ADML system of the vehicle 10 during the process of determining the location of the hands-free key inside the vehicle 10, that is to say less than 120 kHz. The operating frequency associated with the second power (for example 2 W) is for example at 110 kHz, or less (for example 90 or 100 kHz).

According to a variant embodiment, the system switches to operation conforming to the second power profile only when the speed of the vehicle falls below the threshold value and remains below this threshold value for a duration at least equal to a determined threshold duration. The determined threshold duration is for example equal to 5, 7, 10, or 15 seconds. For example, the threshold duration is equal to 10 seconds. According to this variant, the system switches to operation in accordance with the second power profile when the speed of the vehicle and after the expiry of a duration equal to the threshold duration if the speed of the vehicle remains lower than the threshold speed for a duration equal to the threshold duration.

Such an operating frequency is for example controlled by the computer controlling the wireless charging system. The lowering of the power from the first power level to the second power level is for example controlled by the computer by controlling one or more of the following parameters of the transmitter (of the LC resonant circuit of the transmitter):

- the circuit supply voltage; and or

- the operating frequency of the circuit.

According to a particular embodiment, the lowering of the first power level to the second power level is obtained by lowering the operating frequency of the transmitter from a first frequency (for example equal to 125 or 127.7 kHz) to a second frequency (for example equal to 100 or 110 kHz).

In a fifth optional operation, information representative of the activation of the charge of the wireless communication device is displayed. For example, an LED (from English "Light-Emitting Diode" or in French "diode electroluminescente") is lit to indicate the wireless charging system of the wireless communication device is activated. According to a variant, a first LED is lit according to a first color when the charging system operates according to the first power profile and a second LED is lit according to a second color (different from the first color) when the charging system operates according to the first power profile. According to yet another variant, a single LED is used to indicate the operating mode of the charging system, the LED being configured to light up according to several colors, for example a first color for the first charging power and a second color for the second load power. According to another variant, the display of the information on the activation of the charging system is carried out on a display screen on board the vehicle 10, for example via the display of one or more pictograms (for example a pictogram by operating mode).

In a sixth optional operation, the ADML system of the vehicle 10 (for example the computer in charge of the ADML system) transmits one or more signals to the hands-free key associated with the ADML system of the vehicle 10. Such a signal is emitted in the part of the process for determining the location of the hands-free key inside the vehicle 10, such a signal comprising data representing an authentication request intended for the hands-free key. Such a signal is advantageously transmitted in a frequency band between 120 and 135 kHz, for example at 125 kHz, when the vehicle 10 stops (for example when the speed of the vehicle 10 passes below a threshold, for example below a threshold less than or equal to the threshold for which the system switches from the first charging power to the second charging power.

Thus, the present process has the advantage that the signal or signals emitted by the ADML system as part of the process of determining the location of the hands-free key inside the vehicle 10 are transmitted when the charging power of the system 101 is reduced to the second power level, that is to say when the operating frequency of the system 101 is different (in particular lower) than the lower limit of the frequency band used by the ADML system to transmit the signal.

According to this process, the interference generated by the wireless charging system 101 with respect to the ADML system is reduced, or even eliminated, the operating frequency of the system 101 being different from the frequency of transmission of the signal by the ADML system. .

The charging system is for example activated when a user of the vehicle powers up the vehicle's on-board system. When the user starts the engine of the vehicle 10, the process described above is implemented until the user switches off the engine, the extinction of the engine stopping or inhibiting the charging system of the vehicle 10 .

schematically illustrates a device 2 configured to control a wireless charging system for a wireless communication device on board a vehicle, for example the wireless charging system 101 of the vehicle 10, according to a particular and non-limiting embodiment of the present invention. The device 2 corresponds for example to a device on board the vehicle 10, for example a computer.

The device 2 is for example configured for the implementation of the operations described with regard to the and/or the steps of the process described with regard to the . Examples of such a device 2 include, but are not limited to, on-board electronic equipment such as a vehicle's on-board computer, an electronic computer such as an ECU ("Electronic Control Unit") or a control unit. telematics control, called TCU (from the English "Telematic Control Unit"). The elements of device 2, individually or in combination, can be integrated in a single integrated circuit, in several integrated circuits, and/or in discrete components. The device 2 can be made in the form of electronic circuits or software (or computer) modules or else a combination of electronic circuits and software modules.

The device 2 comprises one (or more) processor(s) 20 configured to execute instructions for carrying out the steps of the method and/or for executing the instructions of the software or software embedded in the device 2. The processor 20 can include integrated memory, an input/output interface, and various circuits known to those skilled in the art. The device 2 further comprises at least one memory 21 corresponding for example to a volatile and/or non-volatile memory and/or comprises a memory storage device which can comprise volatile and/or non-volatile memory, such as EEPROM, ROM, PROM, RAM, DRAM, SRAM, flash, magnetic or optical disk.

The computer code of the onboard software or software comprising the instructions to be loaded and executed by the processor is for example stored on the memory 21.

According to various particular embodiments, the device 2 is coupled in communication with other similar devices or systems and/or with communication devices, for example a TCU (from the English “Telematic Control Unit” or in French “Unité Telematics Control System”), for example via a communication bus or through dedicated input/output ports.

According to a particular and non-limiting embodiment, the device 2 comprises a block 22 of interface elements for communicating with external devices, for example a remote server or the “cloud”, a TCU unit. Block 22 interface elements include one or more of the following interfaces:

- RF radio frequency interface, for example of the Bluetooth® or Wi-Fi® type, LTE (from English "Long-Term Evolution" or in French "Evolution à long terme"), LTE-Advanced (or in French LTE-advanced );

- USB interface (from the English "Universal Serial Bus" or "Universal Serial Bus" in French);

- HDMI interface (from the English “High Definition Multimedia Interface”, or “Interface Multimedia Haute Definition” in French);

- LIN interface (from English “Local Interconnect Network”, or in French “Réseau interconnecté local”).

According to another particular embodiment, the device 2 comprises a communication interface 23 which makes it possible to establish communication with other devices (such as other computers of the on-board system or other servers) via a communication channel 230. The communication interface 23 corresponds for example to a transmitter configured to transmit and receive information and/or data via the communication channel 230. The communication interface 23 corresponds for example to a CAN-type wired network ( from the English "Controller Area Network" or in French "Réseau de Contrôleurs"), CAN FD (from the English "Controller Area Network Flexible Data-Rate" or in French "Réseau de Contrôleurs à Flow de Data Flexible"), FlexRay (standardized by ISO 17458) or Ethernet (standardized by ISO/IEC 802-3).

According to an additional particular embodiment, the device 2 can provide output signals to one or more external devices, such as a display screen, one or more loudspeakers and/or other peripherals (projection system ) via respectively suitable output interfaces. According to a variant, one or the other of the external devices is integrated into the device 2.

illustrates a flowchart of the different steps of a method for controlling a wireless charging system for a wireless communication device on board a vehicle, for example the wireless charging system 101 of the vehicle 10, according to a particular example embodiment and non-limiting of the present invention. The method is for example implemented by a device on board the vehicle 10 or by the device 2 of the , when the vehicle engine is started.

In a first step 31, the current speed of the vehicle is determined or information representative of the current speed is received.

In a second step 32, the charging power of the wireless charging system is controlled according to the speed determined in the first step 31, the charging power being reduced from a first power level to a second power level when the current speed is lower than a determined threshold speed.

According to a variant embodiment, the variants and examples of the operations described in relation to the apply to the process steps of the .

Of course, the invention is not limited to the embodiments described above but extends to a method for controlling the charging power of a mobile communication device on board a vehicle by a wireless charging system integrated into the vehicle which would include secondary steps without departing from the scope of the present invention. The same would apply to a device configured for the implementation of such a method.

The invention also relates to a vehicle, for example an automobile or more generally an autonomous land motor vehicle, comprising the device 2 of the . According to a variant, the vehicle also comprises a wireless charging system controlled by the device 2 and an ADML system.

The invention also relates to a system comprising the device 2 of the (or a set of devices 2) embedded in a vehicle, a wireless charging system (the device 2 being for example integrated into the wireless charging system) and an ADML system.

Claims (10)

A method of controlling a wireless charging system (101) for a wireless communication device, said wireless charging system (101) being embedded in a vehicle (10), said vehicle (10) further comprising a charging system hands-free access and starting, said ADML system, said method being implemented by said vehicle when an engine of said vehicle is running, said method comprising the following steps:
- determination (31) of a current speed of said vehicle (10);
- controlling (32) a charging power of said wireless charging system (101) as a function of said speed, said charging power being reduced from a first power level to a second power level when said current speed is lower than a determined threshold speed. A method according to claim 1, wherein the load power is reduced from said first power level to said second power level when said current speed is below said determined threshold speed for a time longer than a determined threshold time. Method according to Claim 2, for which the said determined threshold duration is equal to 10 seconds. A method according to any of claims 1 to 3, wherein said second power level is less than or equal to 2 W. A method according to any of claims 1 to 4, wherein said first power level is greater than or equal to 15 W. Method according to any one of Claims 1 to 5, for which the said determined threshold speed is equal to 5 km/h. Method according to any one of claims 1 to 6, further comprising a step of displaying information representative of said charging power. Computer program comprising instructions for implementing the method according to any one of the preceding claims, when these instructions are executed by a processor. Device (2) for controlling a wireless charging system (101) for a wireless communication device, said device (2) comprising a memory (21) associated with at least one processor (20) configured for the implementation process steps according to any one of claims 1 to 7. Vehicle (10) comprising the device (2) according to claim 9.