METHOD FOR ACTIVATING A VEHICLE FUNCTION AND ASSOCIATED ACTIVATION DEVICE

Abstract

The invention relates to a method for activating a vehicle function, by an activation device (D), from a "hands-free" access device (SD) and equipped with an accelerometer (ACC), the activation of the function being triggered by a detection of the presence of the device (SD) in a predetermined zone (Z1) and as a function of an authentication result of the device (SD), the device comprising at least one transceiver capable of communicating with said device in ultra wide band (ULB), and in ultra high frequency (BLE), the method comprising the following steps: a) Detection by ultra high frequency, of a presence of the access device in the predetermined zone, b) Authentication of said device by ultra high frequency, c) Acceleration measurements of the access device, and i) If said measurements are representative of a movement of the access device greater than a threshold from a last fixed position,then stopping the ultra high frequency communication and triggering the ultra wide band communication, and activating the vehicle function, ii) Otherwise, if said measurements are representative of a static state of the access equipment, from a last fixed position then maintaining the ultra high frequency communication. Figure for the abstract: Fig. 1,

Description

Title of the invention: METHOD FOR ACTIVATING A VEHICLE FUNCTION AND ASSOCIATED ACTIVATION DEVICE Technical field

[0001] The invention relates to a method for activating a function of a motor vehicle and an associated activation device. The invention applies particularly but in no way limitingly to the function of hands-free access to a motor vehicle using a smart mobile phone, the function being for example the function of locking and unlocking the openings of a motor vehicle. Prior art

[0002] In a motor vehicle, it is known to use vehicle function activation devices capable of detecting the presence of a hand or a foot of a user of the vehicle and thus allowing the locking or unlocking of all or part of the openings of the vehicle, for example the doors or the trunk. For example, the detection of the presence of a user's hand on or in front of a door handle coupled with the recognition of an identifier of a "hands-free" access device worn by this user, allows the locking and unlocking of these openings.

[0003] A so-called "hands-free" access system for a motor vehicle allows an authorized user to lock and / or unlock the openings of his vehicle without having to physically press buttons on a key. To do this, the vehicle identifies portable equipment such as a badge or a remote control carried or even a key, by the user and if the badge or the remote control or the key is located in a predetermined area around the vehicle or in the vehicle and is identified as belonging to the vehicle, then the vehicle automatically locks / unlocks its openings according to the user's intention, without the user having to physically handle a key.

[0004] To do this, when the user approaches the vehicle, communication is established on a wireless communication link between the “hands-free” access equipment, for example an electronic badge or a smart mobile phone, and the vehicle function activation device in order to authenticate said access equipment using its identifier.

[0005] To this end, the activation device comprises at least one radiofrequency antenna allowing reception of the identifier sent by the “hands-free” access equipment. The activation device is connected to an electronic control unit (ECU) of the vehicle to which it transmits the identifier.

[0006] Depending on the location of the portable equipment identified by the vehicle, in said location zones certain actions specific to said location zones are automatically carried out, unlocking / locking or prior switching on of the passenger compartment lighting (also called “welcome lighting” in English).

[0007] Nowadays, however, it is increasingly common to use a mobile phone to perform authentication functions, which makes it possible to avoid using a dedicated electronic badge and thus limit the number of devices. Most mobile phones do not have RF or LF communication means. It therefore becomes necessary to adapt the "hands-free" access and / or starting system to a vehicle so that it can also operate with a mobile phone equipped with other communication standards, such as, for example, "Ultra Wide Band" in English or Ultra Large Band, ULB in French, or by "Bluetooth Low Energy" ® in English or Bluetooth à basse consommation, or by WIFI communication ("Wireless FIdelity" in English or wireless fidelity) and no longer only via radio waves and low frequencies (RF, LF).Ultra wideband (UWB) is a radio modulation technique based on the transmission of very short pulses, often less than a nanosecond. Thus, the bandwidth can reach very high values.

[0008] Communication via Bluetooth is communication at a frequency of around 2.4 GHz.

[0009] The method of activating a vehicle function using a mobile phone then consists of: a. Detect by Bluetooth communication the remote presence of the access equipment, i.e. around 100 m around the vehicle, and establish an initial communication link by Bluetooth between the access equipment and the activation device, b. Recognize the identifier received via Bluetooth by the vehicle. c. Then, detect by ULB, the nearby presence of the access equipment, i.e. within a radius of a few meters, for example approximately 10 m to 15 m around the vehicle, and precisely locate by ULB the position of said equipment in order to activate security vehicle functions such as unlocking, locking, etc.

[0010] However, this method has a major drawback when the vehicle is parked within a radius of 10 m to 15 m around the access equipment and the user does not want to activate a vehicle function. For example, when the vehicle is parked in a garage and the access equipment is placed in a receptacle located in the house adjoining the garage. In this case, all the steps of the above process will be carried out, and the vehicle will be unlocked, then locked, then unlocked, and so on in a cyclical manner without the user wanting to activate these functions.

[0011] The scenario is even more critical when the vehicle is parked in front of the house where the portable equipment is permanently located within the UWB communication range. The vehicle is then unlocked at a recurring frequency and can therefore be easily stolen.

[0012] Another significant drawback of this prior art method lies in the fact that the vehicle battery and the battery of the access equipment will drain very quickly, because they are over-used by these recurring requests and these cyclic locking and unlocking actions. This reduces their lifespan.

[0013] The invention therefore proposes a method for activating a vehicle function and an associated activation device overcoming the drawbacks of the prior art and thus eliminating the risk of theft of the vehicle and extending the life of the vehicle batteries and the portable equipment. Statement of the invention

[0014] The invention relates to a method for activating a vehicle function, by an activation device, from a “hands-free” access device capable of being worn by a user, the access device being provided with an accelerometer, the activation of the function being triggered by a detection of the presence of the device in a predetermined zone around the vehicle, and as a function of an authentication result of the device, the activation device comprising at least one transmitter receiver capable of communicating with said device in ultra wide band, and in ultra high frequency, the method being remarkable in that it comprises the following steps: a. Detection by ultra-high frequency communication of the presence of access equipment in a predetermined area around the vehicle, b. Authentication of said equipment by ultra high frequency communication, c. Acceleration measures of access equipment, and d. If the said measurements are representative of a movement of the access equipment greater than a threshold from a last fixed position, then stopping of the ultra high frequency communication and triggering of the ultra wide band communication, and activation of the vehicle function, e. Otherwise, if said measurements are representative of a static state of the access equipment, from a last fixed position then maintaining communication in ultra high frequency.

[0015] In an improvement of the activation method according to the invention, if said measurements are representative of a movement of the access equipment between a minimum movement and the threshold, then the communication in ultra high frequency is stopped and the communication in ultra wide band is triggered at a reduced transmission frequency and the vehicle function is activated.

[0016] Preferably, said acceleration measurements are transmitted by the access equipment to the activation device.

[0017] The invention also relates to a device for activating a function of a motor vehicle intended to be embedded in the vehicle, the activation of the function being triggered by a detection of the presence of portable “hands-free” access equipment, capable of being worn by a user, in a predetermined area around the vehicle and as a function of an authentication result of said equipment by the vehicle, the activation device comprising at least one Ultra Wide Band and ultra high frequency transmission and reception transmitter capable of communicating with said equipment in ultra wide band and ultra high frequency, the device being remarkable in that it further comprises: a. means of detecting by ultra high frequency the presence of the access equipment in a predetermined zone, b. ultra-high frequency authentication means for said equipment, c. Means for receiving acceleration values ​​at ultra high frequency from said equipment, d. Means for stopping or maintaining ultra high frequency communication and for triggering ultra wide band communication as a function of said acceleration values ​​from a last fixed position.

[0018] In the improvement mode, the device further comprises means for triggering ultra-wideband communication with a reduced frequency as a function of said acceleration values ​​from a last fixed position.

[0019] The invention also applies to any computer program product comprising program code instructions for executing the steps of the method according to any one of the characteristics listed above when said program is executed on a computer.

[0020] The invention also relates to any “hands-free” access equipment to a motor vehicle, capable of being worn by a user, characterized in that it comprises an accelerometer, means for measuring acceleration values ​​and means for transmitting acceleration values ​​at ultra high frequency.

[0021] And finally, the invention applies to any motor vehicle comprising an activation device according to any one of the characteristics listed above. Brief description of the drawings

[0022] Other characteristics and advantages of the invention will become apparent from reading the description which follows. This description is purely illustrative and should be read in conjunction with the appended drawings in which:

[0023] [Fig.l]: [Fig.l] schematically represents the vehicle equipped with the activation device according to the invention, with portable equipment in a static position, located in a predetermined proximity around the vehicle,

[0024] [Fig.2]: [Fig.2] schematically represents the vehicle equipped with the activation device according to the invention, with portable equipment in motion, the motion being greater than a threshold, located in a predetermined proximity around the vehicle,

[0025] [Fig.3]: [Fig.3] schematically represents the vehicle equipped with the activation device according to the invention, with portable equipment in motion, the motion being between a minimum motion and a threshold, located in a predetermined proximity around the vehicle.

[0026] [Fig.4]: [Fig.4] schematically represents the activation device according to the invention,

[0027] [Fig.5]: [Fig.5] is a flowchart representing the different stages of the activation method according to the invention. Description of the embodiments

[0028] In [Fig.l] a motor vehicle V is shown equipped with the activation device D according to the invention. The activation device D comprises at least two transmitter receivers EM1, EM2, EM3, EM4 in Ultra Wide Band ULB and in ultra High Frequency, of the Bluetooth, BLE type, capable of communicating in ultra wide band and in BLE with portable access equipment SD carried by a user U.

[0029] The activation device D further comprises a central control unit 10 electronically connected to all the Bluetooth LE and ULB transmitter receivers EM1, EM2, EM3, EM4.

[0030] This central control unit 10 makes it possible to manage the transmission and reception of data in ULB, Bluetooth LE via the transmitter receivers. This is known from the prior art and will not be detailed further here.

[0031] Ultra Wide Band ULB communication is understood to mean radiofrequency communication which is based on the transmission of very short pulses, often less than a nanosecond. Thus, the bandwidth can reach very high values ​​between 250 and 500 MHz.

[0032] Bluetooth LE communication means communication in ultra high frequency around 2.4 GHz.

[0033] As already explained, the activation method of the prior art consists of: a. Detect by Bluetooth LE communication the remote presence of the SD access equipment, i.e. around 100 m around the vehicle, V and establish a first communication link by Bluetooth Low Energy between the SD access equipment and the activation device D, using at least one transmitter receiver, b. Receive in BLE an identifier of said SD equipment by the vehicle, and recognize the latter as being an identifier of a portable equipment previously associated with the vehicle V, c. Then detect by ULB communication, using at least one transmitter receiver of the activation device D, the nearby presence of the access equipment, i.e. in a zone close to the vehicle, for example between 0 and 15 m around the vehicle, and precisely locate the position of said SD equipment, d. Activate a vehicle function Fl depending on the distance separating said SD equipment from the vehicle V, for example automatically unlocking the door when the user is near the door, or turning on the air conditioning, heating, radio or remotely controlling the vehicle V for automatic parking mode, when the user U is a few meters from his vehicle.

[0034] As explained previously, if the SD access equipment is within the Ultra Wide Band ULB communication range, the vehicle function is activated even if the user did not want it, which poses a real problem in terms of security and battery life.

[0035] The invention proposes an activation device D overcoming the drawbacks of the prior art.

[0036] According to the invention, the “hands-free” access equipment SD comprises an integrated accelerometer ACC and is capable of measuring acceleration values ​​according to time t and of transmitting said values ​​to the activation device D.

[0037] The SD access equipment also comprises a processor 200 and a memory 201 (see [Fig.4]) in which instructions are recorded making it possible to configure the processor to execute certain particular processing operations, in particular to implement the steps of the activation method, according to the embodiment as described below.

[0038] According to the invention, the activation device D further comprises (see [Fig.4]): a. means of detecting Ml by ultra high frequency the presence of the access equipment SD in a predetermined zone Zl, b. ultra high frequency M2 authentication means of said SD equipment, c. Means of receiving M3 in ultra high frequency the acceleration values ​​from said SD equipment, d. Means for stopping or maintaining the ultra high frequency communication M4 and for triggering M5 the ultra wide band communication as a function of said acceleration values.

[0039] In an improvement of the invention, the activation device further comprises means M6 for reducing an ultra wide band ULB communication frequency as a function of said acceleration values.

[0040] Preferably, but in no way limiting, the detection means M1, the authentication means M2, the reception means M3 and the means M4 for stopping or maintaining the ultra high frequency communication and the means M5 for triggering the ultra wide band communication are included in the central control unit 10 (see [Fig.4]) and are presented partially or entirely in the form of software.

[0041] The central control unit 10 also comprises a processor 100 and a memory 101 (see [Fig.4]) in which instructions are recorded for configuring the processor to execute certain particular processes, in particular to implement the steps of the activation method, according to the embodiment as described below.

[0042] The detection means M1 consist of means for transmitting, receiving and processing data received from the access equipment SD by ultra high frequency, included in the transmitters and receivers EM1, EM2, EM3, EM4 and in the central control unit 10. Said means make it possible to detect the presence of said equipment in a predetermined zone Z1 around the vehicle with a radius of 10 m to 15 m. This is known from the prior art.

[0043] The authentication means are presented in the form of software making it possible to recognize the identifier ID of the access equipment SD, and to authenticate it in order to detect whether said equipment is indeed authorized to activate the functions of the vehicle V. This is known from the prior art.

[0044] The means M3 for receiving the acceleration values ​​ACC(t) from the access equipment consist of the transmitters EM1, EM2, EM3, EM4 and the central control unit 10.

[0045] The means for stopping or maintaining the communication in ultra high frequency BLE M4 and for triggering M5 the communication in ultra wide band ULB as a function of said acceleration values ​​are in the form of software.

[0046] More particularly, upon receipt of the acceleration values ​​according to the time ACC(t), the activation device D determines a displacement d1, d2 (see figures 2 and 3) or a distance traveled d of the activation device D according to the time, more particularly since the last static position of said equipment which was memorized.

[0047] The determination of a displacement dl, d2 from a previous position PI of the access equipment SD using the acceleration values ​​ACC(t) is known to those skilled in the art. Those skilled in the art know how to calculate a distance dl, d2 on the basis of acceleration values ​​ACC(t) over time and a starting position, so this will not be detailed here.

[0048] The means for stopping or maintaining M4 the ultra high frequency communication M4 and for triggering M5 the ultra wide band communication ULB as a function of said acceleration values ​​ACC(t) therefore comprise: a. Means for calculating a distance traveled dl, d2 by the access equipment SD as a function of said acceleration data, b. Means for comparing said distance dl, d2 with a threshold value ds, for example ds is equal to 50 cm. c. Means for stopping communication in ultra high frequency BLE and triggering communication in ultra wide band ULB if the distance dl, d2 is greater than the threshold value ds, d. Means of maintaining communication in ultra high frequency BLE, if the distance dl, d2 is less than the threshold value ds.

[0049] In an improvement of the invention, the activation device D further comprises: a. Means of comparison M7 of said distance dl, d2 with a minimum displacement value dmin, b. Means for stopping the BLE ultra high frequency communication and for starting the BLE ultra wide band communication with a reduced transmission frequency F M8, if the distance dl, d2 is greater than the minimum displacement dmin but less than the threshold value ds.

[0050] This will be explained below.

[0051] The activation method according to the invention which is illustrated in [Fig.5] will now be described.

[0052] In a preliminary step E0, an ultra high frequency BLE communication is established between the activation device D and the access equipment SD. This communication is made possible because the SD access equipment is located in a predetermined zone ZI around the vehicle which is included in the BLE communication range of the vehicle V.

[0053] In a first step E1, the access equipment SD is authenticated, for this it exchanges by ultra high frequency communication its own identifier ID with the activation device D which verifies that said equipment has been paired beforehand with the vehicle and is authorized to activate vehicle functions.

[0054] In a second step E2, the access equipment measures according to time t and stores acceleration values ​​ACC(t) using its integrated ACC accelerometer.

[0055] Preferably, the acceleration measurements ACC(t) are carried out continuously, stored and transmitted to the activation device D.

[0056] The distance traveled d1, d2 is determined by the activation device D from a previous static position of the equipment SD which has been previously stored for a predetermined duration At. For example, the access equipment SD has remained in a static position for At=5s, and therefore its acceleration values ​​have not changed during this predetermined duration, the next estimation of the distance traveled d will be carried out from this static position, and from the acceleration measurements of the access equipment SD which have been received by the activation device D from said static position.

[0057] The calculation of distance traveled dl, d2 is carried out continuously or at a fixed frequency.

[0058] During a third step 3a, the distance traveled dl, d2 thus estimated using the acceleration values ​​received from the last stored static position is compared to a threshold value ds. For example ds=50 cm.

[0059] If the distance traveled dl, d2 from the last static position is greater than the threshold value of 50 cm, then the ultra high frequency BLE communication is stopped and the ultra wide band ULB communication is started (step E4c). This is illustrated in [Fig.2], the distance traveled dl from the static position PI is greater than ds=50 cm.

[0060] Indeed, it is then considered that the user has moved significantly in relation to his vehicle and consequently that he wishes to activate a vehicle function.

[0061] ULB communication then makes it possible to locate the access equipment SD more precisely around the vehicle V in the predetermined zone Zl, and to activate a vehicle function according to its position (step E5c).

[0062] If the distance traveled dl, d2 since the last static position is less than the threshold value ds of 50 cm, then the communication in ultra high frequency BLE is maintained (step E4a). Indeed, in this case, the movement of the user is not considered significant, and sufficient to detect an intention to activate vehicle function. BLE communication is therefore maintained and the process returns to step E0 of ultra high frequency communication.

[0063] In an improvement of the invention, if the distance traveled d1, d2 from the last static position is less than the threshold value ds of 50 cm, but greater than a minimum displacement for example dmin of 10 cm (step E3b), then the communication in ultra high frequency BLE is stopped and the communication in ultra wide band ULB is started but with a reduced transmission frequency Fmin (step E4b). Otherwise the communication in ultra high frequency BLE is maintained.

[0064] For example, the transmission frequency in ultra wide band ULB is around 10Hz and the reduced transmission frequency in ULB Fmin can be around 2Hz.

[0065] In this case, it is indeed considered that the user has moved or has started to move, so it is advisable to activate the ULB ultra wide band communication. However, as the movement is of low amplitude, it is preferable to reduce the transmission frequency in order to reduce the energy consumption of the batteries. This is illustrated in [Fig.3], the distance traveled d2 from the static position P3 is between 20 cm and 50 cm.

[0066] The invention is particularly ingenious because it makes it possible to significantly reduce the risk of theft of the vehicle as well as to increase the lifespan of the battery of the access equipment and, to a lesser extent, that of the vehicle.

[0067] ULB communication is in fact only activated when a significant movement of the user is detected.

[0068] The invention is particularly easy to implement and inexpensive, since the device primarily comprises software means.

Claims

1. Claims Method for activating a vehicle function, by an activation device (D), from a "hands-free" access device (SD) capable of being worn by a user (U), the access equipment being provided with an accelerometer (ACC), the activation of the function being triggered by a detection of the presence of the equipment (SD) in a predetermined zone (Zl) around the vehicle (V), and according to an authentication result of the equipment (SD), the activation device comprising at least one transceiver (EM1, EM2, EM3, EM4) capable of communicating with said equipment in ultra wide band (ULB), and in ultra high frequency (BLE), the method being characterized in that it comprises the following steps: a. Detection by ultra high frequency communication (BL E), of the presence of access equipment (SD) in a predetermined zone (Zl) around the vehicle (step EO), b. Authentication of said equipment (step El) by ultra high frequency communication, c. Acceleration measurements of the access equipment (step E2), and i. upon receipt of the acceleration values ​​according to time ACC(t), the activation device (D) determines a displacement or a distance traveled according to time, from a last fixed position of said equipment which has been memorized, ii. If said measurements (ACC(t)) are representative of a movement of the access equipment (SD) between a minimum movement (dmin) and the threshold (ds) (step E3b), then stopping of the ultra high frequency communication and triggering of the ultra wide band (ULB) communication at a reduced transmission frequency (Fmin) and activation of the vehicle function (step 5c) depending on the position of the access equipment (SD), iii. Otherwise, if said measurements (ACC(t)) are representative of a static state of the access equipment (SD), from a last fixed position then maintained n of ultra high frequency communication (step 4a).

2. Activation method according to any one of the preceding claims, characterized in that said acceleration measurements are transmitted by the access equipment (SD) to the activation device (D).

3. Activation device (D) for a function of a motor vehicle (V) intended to be on board the vehicle, the activation of the function being triggered by a detection of the presence of a portable “hands-free” access device (SD), capable of being worn by a user (U), in a predetermined zone (Zl) around the vehicle (V), and as a function of an authentication result of said equipment by the vehicle (V), the activation device comprising at least one transmitter receiver (EM1, EM2, EM3, EM4) for transmitting and receiving in Ultra Wide Band (ULB) and in ultra high frequency (BLE) capable of communicating with said equipment in ultra wide band and in ultra high frequency, the device being characterized in that it further comprises: a. means of detection (Ml) by ultra high frequency of a presence of the access equipment (SD) in a predetermined zone (Zl), b. ultra high frequency authentication means (M2) of said equipment, c. Means for receiving (M3) in ultra high frequency acceleration values ​​(ACC(t)) from said equipment, d. Means for stopping (M4) or maintaining ultra high frequency communication and for triggering (M5) ultra wide band communication as a function of said acceleration values ​​from a last fixed position. e. means for triggering ultra-wideband communication (M8) with a reduced frequency (Fmin) as a function of said acceleration values ​​from a last fixed position if said measurements (ACC(t)) are representative of a movement of the access equipment (SD) between a minimum displacement (dmin) and the threshold (ds).

4. Motor vehicle (V), characterized in that it comprises an activation device (D) according to the preceding claim.

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