METHOD FOR ACTIVATING A VEHICLE FUNCTION AND ASSOCIATED ACTIVATION DEVICE
The method uses ultra-wideband transceivers to adapt refresh frequencies based on proximity for efficient and rapid vehicle door unlocking, addressing energy consumption and cost issues in existing systems.
Patent Information
- Application Number
- FR2023009961
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-09-20
- Publication Date
- 2025-08-15
- Estimated Expiration
- 2043-09-20
AI Technical Summary
Existing vehicle door unlocking systems consume excessive energy and have slow reaction times due to continuous camera monitoring, and alternative systems using motion sensors are costly.
A method utilizing ultra-wideband transceivers to emit waves at varying refresh frequencies, adapt frequency based on distance, and activate cameras only when a user is within a threshold proximity, combined with visual recognition for efficient and rapid door unlocking.
Reduces energy consumption and reaction time while maintaining precise user detection, achieving rapid and cost-effective door unlocking.
Smart Images
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Abstract
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 vehicle function and an associated activation device. The invention applies particularly to the “hands-free” locking and unlocking of the vehicle by visual recognition of the user. Prior art
[0002] Nowadays it is known to unlock electronic equipment by visual recognition of its user, it is thus possible to unlock a mobile phone.
[0003] Similarly, a user can access his vehicle and unlock the doors by recognizing his face. This allows him to access his vehicle without having to carry a badge, or a key or even a smart mobile phone. For this purpose, the vehicle access method comprises the following steps: a. a preliminary learning phase which allows the collection of biometric information on the people to be identified (also called the enrollment phase), b. a phase of detecting the presence of a face in the image, c. a phase of segmentation and processing of the facial image, d. a phase of recognition and authentication of the face, e. finally, a phase of unlocking the vehicle doors if the face has been authenticated.
[0004] Various solutions are known from the prior art for carrying out these different steps. Thus, it is known to equip the vehicle with cameras in order to detect the presence of a face, and with processing means in order to authenticate the latter. However, this involves permanent monitoring by the cameras, which is relatively energy-intensive. A camera consumes 1 to 2 watts, which is not negligible when the vehicle is stationary. In addition, the reaction time of a camera is relatively high, of the order of 1 to 2 seconds, which can cause a so-called "wall" effect for the user, because the doors then take a certain amount of time to unlock.
[0005] One solution may be to equip the vehicle with a motion sensor, and thus only activate the camera when the user's presence has been detected, thus considerably reducing the camera's power consumption. However, the cost of the complete system is high.
[0006] It therefore proves necessary to remedy the drawbacks of the prior art by offering an inexpensive vehicle function activation process that allows rapid unlocking of doors and consumes little energy.
[0007] The invention proposes a method for activating a vehicle function and an associated activation device satisfying the objectives mentioned above. Statement of the invention
[0008] The invention relates to a method for activating a vehicle function, by an activation device, based on visual recognition of a user, the activation device comprising at least one camera facing the outside of the vehicle, equipped with visual recognition means, at least one ultra-wideband transmitter-receiver, capable of detecting a presence inside the vehicle, the method being remarkable in that the transmitter-receiver is previously modified so that it is capable of transmitting to the outside of the vehicle at different refresh frequencies and in that it comprises the following steps:
[0009] a) emission of ultra-wideband waves at a first refresh frequency towards the exterior of the vehicle,
[0010] b) reception of reflected waves,
[0011] c) detection of presence in a predetermined area around the vehicle,
[0012] d) adaptation of the refresh frequency as a function of a distance (d) between said presence and the vehicle, the frequency being higher when the presence is close to the vehicle,
[0013] e) activation of the camera only when the presence has been detected at a distance less than a threshold value,
[0014] f) identification of presence by visual recognition,
[0015] g) if the presence is identified as being the user then activation of the vehicle function.
[0016] Preferably, the refresh frequency value varies from 1 Hz to more than 100 Hz.
[0017] Advantageously, the distance is determined by calculating a time of flight of the waves and / or by calculating a shift between a frequency of the emitted waves and a frequency of the received reflected waves.
[0018] The invention also relates to a device for activating a vehicle function, the activation being triggered by visual recognition of a user, the activation device comprising at least one camera facing the outside of the vehicle, equipped with visual recognition means, at least one ultra-wideband transmitter-receiver, capable of detecting a presence inside the vehicle, the device being remarkable in that said transmitter-receiver is modified in order to transmit towards the outside of the vehicle and in that it further comprises:
[0019] a) Means for modifying a refresh frequency of the emitted waves,
[0020] b) Means for detecting presence in a predetermined area around the vehicle, and for adapting the detection means as a function of a position of the presence,
[0021] c) Means for adapting the refresh frequency as a function of a distance between said presence and the vehicle, the frequency being higher when the presence is close to the vehicle,
[0022] d) Means for activating the camera only when the presence has been detected at a distance less than a threshold value,
[0023] e) Means for activating the vehicle function as a function of the result of identification of said presence by visual recognition.
[0024] Advantageously, the value of the refresh frequency varies between 1 Hz and more than 100 Hz.
[0025] Judiciously, the means for detecting and adapting said means comprise means for calculating a time of flight of the waves and / or for calculating an offset between a frequency of the emitted waves and a frequency of the received waves.
[0026] The invention also relates 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.
[0027] 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
[0028] 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:
[0029] [Fig.l]: [Fig.l] is a schematic representation of a motor vehicle equipped with the activation device according to the invention,
[0030] [Fig.2]: [Fig.2] is a schematic representation of the predetermined detection zones inside and outside the vehicle,
[0031] [Fig.3]: 1a [Fig.3] is a schematic representation of the three phases of detection, location and authentication of a user according to the activation method according to the invention,
[0032] [Fig.4]: [Fig.4] is a schematic representation of the activation device according to the invention,
[0033] [Fig.5]: [Fig.5] is a flowchart illustrating the steps of the activation process according to the invention. Description of the embodiments
[0034] In [Fig.l] a motor vehicle V is shown, equipped with the device for activating a vehicle function D according to the invention.
[0035] The vehicle function can be either the locking or the unlocking of the openings of the vehicle V, for example the unlocking of the driver's door P, i.e. access to the vehicle V.
[0036] The activation of the function is triggered by the visual recognition of a user authorized to use the vehicle V. A prior authentication of the user's face has been carried out by the vehicle V in order to record and store the data of his face to authorize a subsequent access request.
[0037] Visual recognition for accessing equipment is known to those skilled in the art and will not be detailed further here.
[0038] According to the invention, the activation device D comprises at least one camera C1, C2 facing the outside of the vehicle, equipped with visual recognition means, and an ultra-wideband ULB transmitter and receiver EM1, capable of detecting a presence inside the vehicle. In the example illustrated in [Fig.l], two cameras C1, C2 are located on each side of the driver's door P.
[0039] The camera C1 is thus able to view any object located near the vehicle on the side where the camera is fixed, preferably near the opening, here the door which is to be locked or unlocked.
[0040] The EM1 ultra wide band ULB transmitter receiver is preferably located inside the vehicle V and makes it possible to detect any presence in the passenger compartment, for example the presence of a child.
[0041] In the example illustrated in [Fig.l], two transmitters / receivers EM1, EM2 are located in the passenger compartment of the vehicle V. Two transmitters instead of one allow more precise localization of a presence in the passenger compartment.
[0042] According to the invention and unlike the prior art, the transmitters EM1, EM2 have been modified in order to emit ULB waves which extend outside the passenger compartment in a predetermined zone Z3, Z11, Z21 around the vehicle V, for example within a radius of 5 meters around the vehicle V.
[0043] For this purpose, the transmitters and receivers EM1, EM2 have been modified in the following manner, each transmitter comprises two antennas, one antenna oriented towards the inside of the vehicle V, and one antenna oriented towards the outside of the vehicle V, which therefore have different radiations due to their orientation.
[0044] A switch is connected to both antennas and allows one to be selected or either of the two antennas. This device is known from the prior art.
[0045] Alternatively, each transmitter receiver contains two antennas oriented in the same way, but offset in phase, and in phase opposition, the radiation pattern thus produced is oriented both towards the inside and towards the outside of the vehicle V. This device is also known from the prior art and will not be developed further here.
[0046] The activation device D further comprises a central control unit 10 electronically connected to the transmitters EM1, EM2 and to the cameras C1, C2.
[0047] This central control unit 10 makes it possible to manage the transmission and reception of waves in ULB via the transmitters and receivers EM1, EM2, but also to trigger the activation or stopping of the cameras C1, C2 and to process the information from said cameras. The central control unit 10 therefore also comprises image processing and visual recognition means. This is known from the prior art and will not be detailed further here.
[0048] Ultra Wide Band (ULB) communication is understood to mean radio frequency 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 and beyond.
[0049] According to the invention, the activation device D further comprises: a. Means of modifying Ml a refresh frequency F of the emitted waves, b. Means M2 for detecting presence in a predetermined area around the vehicle and for adapting said means according to a position of said presence, c. Means M3 for adapting the refresh frequency F as a function of a distance d, between said presence and the vehicle, the frequency being higher when the presence is close to the vehicle, d. Means of activating M4 the camera only when the presence has been detected at a distance d less than a threshold value, e. Means of activating M5 the vehicle function based on the result of identification of said presence by visual recognition.
[0050] The modification means M1, the detection means M2, the frequency adaptation means M3, the location means M4 and the camera activation means M4 and the vehicle function activation means M5, are preferably in the form of software included in an integrated circuit of the central control unit 10 (see [Fig.4]).
[0051] The refresh rate F is understood to mean the number of frames emitted per second. Each frame contains several waves of predefined duration, for example 5 ms. The refresh rate thus makes it possible to adapt the speed with which the EM1, EM2 transmitter / receiver in ULB receives data in its coverage area.
[0052] Thus according to the invention, the modification means M1 are capable of modifying the refresh frequency F of the waves emitted in ULB from F0=1 Hz to more than F2=100 Hz. The higher the refresh frequency F, the more energy the transceiver consumes, here the electricity coming from the battery of the vehicle V, and the more precise the location of the presence. Conversely, the lower the refresh frequency F, the less energy the transceiver EM1, EM2 consumes, but the location of a presence is also less precise.
[0053] The invention intelligently proposes to use the variation in refresh frequency F to accurately detect a presence in an area close to the vehicle V, Z1 1, Z21, and thus to activate only the cameras C1, C2 to trigger visual recognition while saving battery power when the presence is in the area close to the vehicle V.
[0054] The means M2 for detecting a presence in a predetermined zone and for adapting said means according to the position of the presence relative to the vehicle or to the predetermined zones, comprise: a. means for calculating a frequency shift between the frequency of the emitted waves and the frequency of the reflected waves which are received, as well as, b. means for calculating a flight time of the round trip of the waves between the transmitter / receiver EM1 EM2 and the presence, as well as, c. means for determining an angle of arrival of the reflected waves received by the transmitter receiver EM1, EM2
[0055] These different means are known to those skilled in the art.
[0056] In order to reduce energy consumption, when the refresh frequency is slow, for example F0=1 Hz, but sufficient to detect a presence in the predetermined zone Z3, the furthest from the vehicle V, the detection means M2 consist only of means for calculating the frequency shift. These means are of the Doppler radar type. To detect the presence in a predetermined zone close to the vehicle Z11, Z21, then the flight time of the waves and the angle of arrival of the reflected waves are determined to obtain a more precise location of the presence around the vehicle V and thus calculate a distance d separating the presence from the vehicle V.
[0057] Alternatively, in the case of two transmitters / receivers EM1, EM2, triangulation, or cross-referencing between the data from the two transmitters allows for even more precise localization.
[0058] The activation means M4 of the camera make it possible to start the camera(s) Cl, C2 in the case where the presence has been detected by the transmitters EM1 EM2 in the close zone Zll, Z21 (see [Fig.2]) around the vehicle, i.e. only when said presence is located at a distance d from the vehicle, less than a predefined threshold value
[0059] Finally, the means for activating the vehicle function M5 lock or unlock the openings of the vehicle V depending on the result of the visual recognition of the user U on the images captured by the cameras C1, C2.
[0060] The central control unit 10 also comprises a processor 100 and a memory 101 (see [Fig.4]) in which instructions are recorded making it possible to configure the processor to execute certain particular processes, in particular to implement the steps of the activation method, according to the embodiment as described below.
[0061] The activation method, illustrated in [Fig.5] will now be described. This method illustrates the case where the activation function and the unlocking of the openings of the vehicle V.
[0062] During a first step E1, an emission of Ultra Wide Band waves with a first low refresh frequency F0, of the order of 1 Hz, is triggered by the transmitters EM1, EM2 in the predetermined zone Z3, that is to say in a radius of approximately 5 meters around the vehicle V. This mode of emission with a very low refresh frequency F0 has the advantage of consuming very little electrical energy, of the order of 10 mW.
[0063] If a human presence or an object is located in the predetermined zone (step El) Z3, i.e. the zone furthest from the vehicle V, the emitted waves are then reflected by this presence and received in return by the vehicle V. This is illustrated on the left of [Fig.3].
[0064] The processing and analysis of the reflected waves, for example the calculation of the frequency shift, as for a DOPPLER radar, makes it possible to detect the presence in the predetermined zone Z3 (for example 5 meters around the vehicle V),
[0065] If there is a presence in the predetermined zone (step E1), then the refresh frequency is increased to a second value F1, higher than the first, for example of the order of 10 Hz. The emission of waves at this refresh frequency F1 (step E2) is certainly more energy-consuming, approximately 150 mW, but makes it possible to determine with more precision the location of the presence and to confirm its belonging to the predetermined zone Z3.
[0066] This is illustrated by the middle figure of [Fig.3].
[0067] If said presence is confirmed in the predetermined zone remote from the vehicle Z3 (step E3), the refresh frequency then increases to a third value F2 of approximately 100 Hz. At this speed, the electrical consumption is higher still, of the order of 300 mW, but the emission of waves at this frequency (step E4) makes it possible to determine whether said presence has approached the vehicle and is now in a zone close to ZI 1, Z21 of the vehicle V, for example within a radius of 2 meters around the vehicle V and to locate it precisely. This is illustrated on the left of [Fig.3].
[0068] In this case, the invention proposes to use the calculation of the flight time, combined with the calculation of the frequency phase shift between the emitted waves and the received waves and optionally the determination of the angle of arrival of the reflected waves in order to estimate more precisely the distance d between said presence and the vehicle V.
[0069] If the presence is in the nearby zone Z1 1, Z21 (step E5), the use of the transmitter receiver EM1, EM2 as a Doppler radar makes it possible to detect a presence in the coverage zone of said transmitter, i.e. 5 meters around the vehicle and therefore to detect the intrusion of a presence in this zone Z3.
[0070] The use of the flight time and the angle of arrival make it possible to locate the presence more precisely and to know if it is in the close zone Z1 1, Z21 of the vehicle in order to activate the camera C1, C2. Thus, depending on the position of the presence, not only the refresh rate is adapted but also the means used to detect said presence.
[0071] If the presence is at a distance d less than a predefined threshold value, for example less than 2 meters from the vehicle, then the cameras C1, C2 are then activated (step E6), to capture an image of said presence.
[0072] The image processing software then makes it possible to recognize or not (step E7) the face of an authorized user U) entering the vehicle V. If the user U is authenticated (step E7), then the function, here the unlocking of the openings is activated (step E8a), otherwise no function is activated (step E8b), if the result of the visual recognition does not recognize an authorized user.
[0073] In the case of locking, the steps (not illustrated) are as follows. In the first step, UWB waves are emitted at a first frequency F3 = 100 Hz towards the outside of the vehicle, the reflected waves are then received by the activation device D. The user having been detected beforehand as being inside the vehicle by the activation device D, used to detect a presence in the passenger compartment, the first refresh frequency F0 used is immediately the highest. The analysis and processing of the frequency of the waves received and / or the round-trip flight time of the waves makes it possible to determine the distance d separating the user U from the vehicle V.
[0074] When the user leaves his vehicle, the distance is then less than the threshold value because the user U is located in a zone close to ZI 1, Z21 of the vehicle V.
[0075] In this case, the camera(s) C1, C2 are activated to capture images of the presence, then to carry out a visual recognition of said presence.
[0076] If the user is identified as authorized to access his vehicle V, then the locking of the openings is triggered.
[0077] The invention is particularly ingenious, as it saves energy and requires few modifications and is therefore inexpensive.
Claims
1.
2.
3.
4. Claims Method for activating a vehicle function, by an activation device (D), based on visual recognition of a user (U), the activation device (D) comprising at least one camera (Cl, C2) facing the outside of the vehicle, equipped with visual recognition means, at least one ultra-wideband (ULB) transceiver (EM1, EM2), capable of detecting a presence inside the vehicle, the method being characterized in that the transceiver (EM1, EM2) is previously modified so that it is capable of transmitting to the outside of the vehicle at different refresh frequencies (F) and in that it comprises the following steps: a. emission of ultra-wideband waves at a first refresh frequency (FO) towards the exterior of the vehicle, b. reception of reflected waves, c. presence detection in a predetermined zone (Z3, ZI 1, Z21) around the vehicle, d. adaptation of the refresh frequency (Fl, F2) as a function of a distance (d) between said presence and the vehicle, the frequency being higher when the presence is close to the vehicle, e. activation of the camera (Cl, C2) only when the presence has been detected at a distance lower (d) than a threshold value, f. identification of presence by visual recognition, g. if the presence is identified as being the user (U) then activation of the vehicle function. Activation method according to the preceding claim, characterized in that the value of the refresh frequency (FO, Fl, F2) varies from 1 Hz to more than 100 Hz. Activation method according to any one of the preceding claims, characterized in that the distance (d) is determined by calculating a time of flight of the waves and / or by calculating an offset between a frequency of the emitted waves and a frequency of the received reflected waves. Device (D) for activating a vehicle function, the activation being triggered by visual recognition of a user (U) the activation device comprising at least one camera (Cl, C2) facing the outside of the vehicle, equipped with visual recognition means, at least one ultra wide band (ULB) transceiver (EM1, EM2), capable of detecting a presence inside the vehicle, the device (D) being characterized in that said transceiver (EM1, EM2) is modified in order to transmit towards the outside of the vehicle and in that it further comprises: a. Means for modifying (Ml) a refresh frequency (FO, Fl, F2) of the transmitted waves, b. Means for detecting presence (M2) in a predetermined zone (Z3, ZI 1, Z21) around the vehicle, and for adapting the means according to a position of the presence, c.Means for adapting the refresh frequency (M3) as a function of a distance (d) between said presence and the vehicle, the frequency being higher when the presence is close to the vehicle, d. Means for activating (M5) the camera (Cl, C2) only when the presence has been detected at a distance (d) less than a threshold value, e. Means for activating (M6) the vehicle function as a function of the result of identification of said presence by visual recognition.
5. Activation device (D) according to the preceding claim, characterized in that the value of the refresh frequency (FO, Fl, F2) varies between 1 Hz and more than 100 Hz.
6. Activation device (D) according to any one of claims 4 or 5, characterized in that the detection means (M2) and adaptation of said means comprise means for calculating a flight time of the waves and / or for calculating an offset between a frequency of the emitted waves and a frequency of the received waves.
7. A computer program product comprising program code instructions for executing the steps of the method according to any one of claims 1 to 3 when said program is executed on a computer.
8. Motor vehicle (V), characterized in that it comprises a device activation (D) according to any one of claims 4 to 6.