Method for locking and unlocking a motor vehicle door and associated locking and unlocking device

Abstract

The invention proposes a method for locking or unlocking a door (P) of a vehicle (V), by means of a locking / unlocking device (D) mounted on the vehicle, comprising at least two high-frequency communication transceivers (Tx1, Tx2) capable of communicating with a user's portable device (SD), of which a first transceiver (Tx1) is located in the door, and a second transceiver (Tx2) is located inside the vehicle, the method being characterized in that it comprises the following steps: a) Detection of the presence of the user's portable device in a predetermined zone (Z1) around the vehicle, b) If a portable device has been detected, emission of waves between the two transceivers, c) Measurement of a time of flight (TOF1, TOF2) of said waves, d) Comparison between said measured time of flight with a predetermined time of flight (TOF).e) Unlocking or locking the door depending on the comparison result. Figure for the summary: Fig. 3,

Description

Title of the invention: Method for locking and unlocking a motor vehicle door and associated locking and unlocking device Technical field

[0001] The invention relates to a method for locking and unlocking a door of a motor vehicle. The invention applies more particularly to so-called "hands-free" access to the vehicle. Prior art

[0002] Nowadays, vehicle door handles are equipped with so-called "hands-free" locking / unlocking devices for a door. The detection of a user's hand approaching the handle coupled with the recognition of a "hands-free" electronic remote access control badge, carried by the same user, allows the vehicle's openings to be locked and unlocked remotely. Thus, when the user, carrying the corresponding electronic badge and identified by the vehicle, wishes to unlock the vehicle, he or she touches the vehicle's door handle and the vehicle's openings are then automatically unlocked. By approaching or pressing a specific location on the vehicle's door handle, called the "unlocking zone", the door (or alternatively all the openings) is (are) unlocked (unlocked) without any further action by the user.Conversely, when the user, still wearing the necessary badge and identified by the vehicle, wishes to lock his vehicle, he closes the door of his vehicle and momentarily presses another specific point on the handle, called the "locking zone". This gesture automatically locks the vehicle's openings.

[0003] These locking / unlocking devices generally comprise two capacitive sensors, in the form of two electrodes electrically connected to a printed circuit, integrated in the door handle each in a specific locking or unlocking zone. Generally, one electrode is dedicated to each zone, that is to say one electrode is dedicated to detecting the approach and / or contact of the user's hand in the locking zone and one electrode is dedicated to detecting the approach and / or contact of the user's hand in the unlocking zone.

[0004] The unlocking / locking device further comprises a radio frequency antenna, for example in Ultra Wide Band (or “UWB” in English, Ultra Wide Band), in Wifi®, in Bluetooth® or any other type of radio frequency communication, including high and ultra high frequency. The detection device is connected to the cal The vehicle's electronic control unit (ECU) and sends it a presence detection signal. The vehicle's electronic control unit has previously identified the user as being authorized to access the vehicle, or alternatively, following receipt of this presence detection signal, it carries out this identification. To do this, it sends an identification request via the radio frequency antenna to the badge (or remote control) carried by the user. This badge sends its identification code in response, via radio frequency waves, to the vehicle's electronic control unit. If the electronic control unit recognizes the identification code as the one authorizing access to the vehicle, it triggers the locking / unlocking of the door (or all openings).If, on the other hand, the electronic calculator has not received an identification code or if the identification code received is incorrect, locking or unlocking does not take place.

[0005] Such vehicles are therefore equipped with door handles comprising such a device itself comprising a radiofrequency antenna, and two electrodes connected to a microcontroller, integrated in a printed circuit and supplied with voltage.

[0006] However, this prior art unlocking / locking device has major drawbacks.

[0007] In this case, the detection of a user's approach by the capacitive sensors is not robust and generates false detections.

[0008] In particular, under certain environmental conditions, when raindrops or snowflakes come into contact with the door handle, they increase the value of the capacitance measured by the capacitive sensors, thus triggering false detections.

[0009] In addition, the cost of the device is not negligible.

[0010] The invention proposes a locking / unlocking method and device which overcomes the drawbacks of the prior art. Statement of the invention

[0011] The invention proposes a method for locking or unlocking a door of a vehicle, by a locking / unlocking device on board the vehicle, comprising at least two high-frequency communication transceivers, capable of communicating with a user's portable equipment, of which a first transceiver is located in the door, and a second transceiver is located inside the vehicle, the method being remarkable in that it comprises the following steps: a. Detection of presence of the user's portable equipment in a predetermined area around the vehicle, b. If portable equipment has been detected, emission of waves between the two transceivers, c. Measurement of a time of flight of said waves, d. Comparison between said measured flight time with a predetermined flight time, e. Unlocking or locking the door depending on the result of the comparison.

[0012] In a preferred embodiment of the method according to the invention, the door is first equipped with two surfaces identifiable by the user, an unlocking surface and a locking surface, and in that: a. When the user approaches the unlocking surface, the flight time is greater than a first threshold, and b. When the user approaches the locking surface, the flight time is greater than a second threshold.

[0013] Advantageously, if the flight time is greater than the first threshold, then unlocking is activated, and if the flight time is greater than the second threshold, then locking is activated.

[0014] Judiciously, the predetermined flight time was measured beforehand in the absence of the portable equipment in the predetermined area around the vehicle.

[0015] The invention also applies to a device for locking or unlocking a motor vehicle door, intended to be installed in said vehicle, comprising at least two high-frequency communication transceivers capable of communicating with a user's portable equipment, of which a first transceiver is located in the door and a second transceiver is located inside the vehicle, the device being characterized in that it is further capable of: a. Detect a presence of the user's portable equipment in a predetermined area around the vehicle, b. Control the emission of waves between the two transmitters-receivers, depending on the detection, c. Measure a time of flight of said waves, d. Compare the said measured flight time with a predetermined flight time, e. Unlock or lock the door according to the result of the comparison.

[0016] According to the preferred embodiment of the invention, the device comprises on the door two surfaces identifiable by the user, an unlocking surface and a locking surface.

[0017] The device further comprises: a. Means of comparing flight time to a first threshold, and b. Means for comparing the flight time to a second threshold, and in that it is capable of unlocking the door based on a result of comparison with the first threshold and of locking the door based on a result of comparison with the second threshold.

[0018] The invention 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.

[0019] Finally, the invention applies to any motor vehicle comprising a locking or unlocking device according to any one of the characteristics listed above. Brief description of the drawings

[0020] 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:

[0021] [Fig.l]: [Fig.l] schematically represents a motor vehicle equipped with the locking / unlocking device according to the invention,

[0022] [Fig.2]: [Fig.2] schematically represents a vehicle door handle comprising an unlocking surface and a locking surface identifiable by the user according to the invention,

[0023] [Fig.3]: [Fig.3] schematically represents the case of a user's hand approaching the unlocking surface and the locking surface and its impact on the flight time between the two transmitters compared to the case without a hand,

[0024] [Fig.4]: [Fig.4] is a flowchart illustrating the locking / unlocking method according to the invention,

[0025] [Fig.5]: [Fig.5] is a diagram representing the evolution of the flight time between the two transmitter-receivers according to the time t, in a first case, with the approach of the user's hand towards the unlocking surface and in a second case with the approach of the user's hand towards the locking surface. Description of the embodiments

[0026] In [Fig.l] is shown a motor vehicle V equipped with the locking device D according to the invention.

[0027] The device D is equipped with at least two transceivers Txl, Tx2, a first transceiver Txl of which is located in the driver's door, for example the left front door 100 of the motor vehicle, and a second transceiver Tx2 of which is located inside the vehicle V, for example in the passenger compartment.

[0028] It is necessary for the implementation of the invention that the two transmitter-re- receivers are not each located near an opening of the vehicle V.

[0029] The transceivers Txl, Tx2 are capable of communicating in radio frequency, for example in high or ultra high frequency, such as in ultra wide band ULB (or "Ultra Wide Band", in English), in Wifi, or in Bluetooth with a portable user equipment SD, such as a smart mobile phone SD. Thanks to this bidirectional communication between the transceivers Txl, Tx2, and the portable access equipment SD, the device D is capable of knowing the position of said equipment SD relative to the vehicle V and also capable of checking its identifier in order to ensure that it corresponds to an identifier previously paired with the vehicle V. If the portable equipment SD is located in a predetermined zone ZI around the vehicle V and its identifier has been authenticated, then the openings of the vehicle V can be locked or unlocked according to the "hands-free" access procedure known to those skilled in the art.

[0030] The invention will be described here using ultra-wideband communication. Ultra-wideband communication is a radio modulation technique that is based on the transmission of very short pulses, often less than a nanosecond, and over a wide frequency spectrum. Thus, the bandwidth can reach very large values. It is generally considered that UWB must have a bandwidth to center frequency ratio of at least 20%, or a bandwidth of 250 MHz or more.

[0031] The device D can thus detect the presence of the portable equipment SD in a predetermined zone ZI around the vehicle, authorizing the “hands-free” locking of the vehicle V.

[0032] According to the invention, the device D is also capable, if the portable equipment SD has been detected in the predetermined zone ZI, of: a. Control the emission of high frequency waves between the two transmitter-receivers Txl, Tx2, b. Measure a flight time TOF1, TOF2 of the said waves between the two transmitter receivers Txl, Tx2, c. Compare said measured flight time TOF1, TOF2 with a predetermined flight time TOF, d. Unlocking or locking the door according to the result of the comparison.

[0033] For this purpose, as illustrated in [Fig.4], the device D comprises: a. means MO for detecting the presence of the portable equipment SD in the predetermined zone Zl, b. Means Ml for controlling the emission of high-frequency waves between the two transmitters Txl, Tx2, c. M2 means of measuring the time of flight TOF1, TOF2 between the two Txl, Tx2 transmitters and receivers, d. M3 means of comparison between the flight time thus measured with a predetermined TOF flight time, e. Means M4 for unlocking or locking the door 100 depending on the result of the comparison.

[0034] The device D 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 processes, in particular to implement the steps of the locking or unlocking method according to the embodiment as described below.

[0035] The said means listed above, the detection means MO, the high-frequency wave emission control means M1, the time-of-flight measurement means M2, the comparison means M3, the unlocking / locking means M4, the processor 200 and the memory 201 are in the form of software, and are, for example, but in no way limiting in itself, included in a central control unit 10 (see [Fig. 4]) electronically connected to the two transmitters / receivers Txl, Tx2 as well as to electrical unlocking or locking means of the door 100.

[0036] In an improvement of the invention, the device D also comprises: a. Means M5 for comparing the flight time to a first threshold A1, the device D being capable of controlling the unlocking as a function of the result of said comparison and b. Means M6 for comparing the flight time to a second threshold A2, the device D being capable of controlling the locking according to the result of said comparison.

[0037] For this purpose, the door handle P 100 comprises two surfaces easily identifiable by the user U, for example oriented towards the outside of the vehicle V, an unlocking surface SI and an unlocking surface S2 distinct from the unlocking surface SI (cf. [Fig.2]).

[0038] The approach of the hand M of the user U towards the first surface SI respectively towards the second surface S2 increases the difference between the measured flight time TOF1, TOF2 between the two transmitters Txl, Tx2, and the predetermined flight time TOF (cf. [Fig.3]) and said difference is then greater than the first threshold A1 and respectively the second threshold A2.

[0039] The predetermined flight time TOF between the two transceivers Txl, Tx2 was measured beforehand without any hand M near the handle P, nor near the first surface SI, nor near the second surface S2.

[0040] Thus, the approach of the hand M towards the unlocking surface SI, respectively towards the locking surface S2 modifies the flight time between the two transmitter receivers Txl, Tx2 and thus allows the unlocking or unlocking to be triggered (see [Fig.3]).

[0041] Of course, there can only be one surface allowing either unlocking or locking to be activated. The approach of the user's hand M towards this single surface increases the flight time TOF1, TOF2 between the two transmitter receivers Txl, Tx2 and command: a. Either the locking, if the vehicle was previously unlocked, b. Either unlocking, if the vehicle was previously locked, as described below.

[0042] The locking or unlocking method according to the invention, illustrated in [Fig.5] will now be described.

[0043] In a preliminary step E0, it is detected that the portable user equipment SD is located in the predetermined zone ZI around the vehicle, said zone allowing “hands-free” access to the vehicle V. This detection step is known from the prior art and will not be detailed further here.

[0044] In a first step E1, once the presence of the portable equipment SD has been detected in the predetermined zone Z1, the device D controls the emission of high-frequency waves, for example in Ultra Wide Band between the two transceivers Txl, Tx2. In this case, either the first transceiver Txl emits waves towards the second transceiver Tx2, or vice versa.

[0045] Once the waves have been received by either the second transceiver Tx2 or the first Txl, the time of flight TOF1, TOF2 of the waves between the two transceivers Txl, Tx2 is determined (step E2).

[0046] Then, during the following steps E3a, E3b the flight time TOF1, TOF2 thus determined is compared to a predetermined flight time TOF.

[0047] Said predetermined flight time TOF was previously measured between the two transmitter-receivers Txl, Tx2 without any presence of the hand M in the predetermined zone ZL

[0048] If the result of the comparison between the measured flight time TOF1 and the predetermined flight time TOF is greater than a first threshold A1 (step E3a), this means that the user's hand is approaching the unlocking surface S1 and the unlocking DV of the door 100 is triggered (step E4a).

[0049] If the result of the comparison between the measured flight time TOF2 and the predetermined flight time TOF is greater than a second threshold A2 (step E3b), this means that the hand M of the user approaches the locking surface and the locking V of the door 100 is triggered (step E4b).

[0050] Of course, there may be only one surface S, allowing both locking and to unlock the door 100. This embodiment is illustrated in dotted lines in [Fig.5]. In this case, the measured flight time TOF1 is compared with the predetermined flight time TOF and if the comparison is above the first threshold A1 (step E3a) (which may be of a different value than the first threshold used with the unlocking surface), then either unlocking or locking is activated.

[0051] Unlocking is activated (step E4c), if it has been detected that the vehicle V was previously locked (step E3c) and conversely locking is activated (step E4d), if it has been detected that the vehicle was previously unlocked (step E3c).

[0052] The applicant noted that the approach of a hand M near the first transmitter receiver Txl located in the door modified in a significant and measurable manner the propagation of the high-frequency ULB waves between the first and second transmitter receiver Txl, Tx2. In this case, the human body has a wave propagation index different from that of air and absorbs and diffracts the waves, thus lengthening their flight time.

[0053] This is illustrated in Figures 3 and 6. In [Fig.3], the flight time TOF between the two transmitters and receivers Txl, Txl is represented without any hand M located near the handle P, nor in the predetermined zone ZI.

[0054] Also shown in [Fig. 3] are the flight times TOF1, TOF2 between the two transmitter-receivers Txl, Tx2, in the presence or approach of the hand M of the user U near the unlocking surface SI and the locking surface S2 respectively. It is clear that a portion of the UWB waves is absorbed or diffracted during its passage in and over the human body. This phenomenon impacts the flight time of the waves between the two transmitter-receivers Txl, Tx2 by lengthening it significantly.

[0055] In [Fig.6], the flight time TOF between the two transmitters and receivers Txl, Tx2 is illustrated at time t. Up to time t0, the flight time TOF is equal to the predetermined flight time TOF, so there is no hand M near the door 100.

[0056] At time t1, the flight time TOF increases considerably by a value greater than a first threshold A1, to reach the value TOF1, this meaning that the user's hand M is approaching the unlocking surface S1 and consequently that the user U wishes to unlock his vehicle V.

[0057] In [Fig. 6] is also illustrated the case, where the hand M of the user U approaches the locking surface S2 at the instant t0. In this case, the flight time TOF increases considerably by a value greater than a second threshold A2, to reach the value TOF2, this meaning that the hand M of the user approaches the locking surface S2 and consequently that he wishes to lock his vehicle V.

[0058] The invention is therefore judicious, because it allows the use of high-frequency transmitters and receivers on board the vehicle and intended to identify and locate a portable access equipment around the vehicle, to detect the presence of a hand near the door handle and therefore unlock or lock the vehicle V.

[0059] The invention is particularly ingenious, because it does away with capacitive sensors and thus their cost and technical drawbacks, and uses components already on board the vehicle to make them perform a function other than that for which they were intended.

[0060] There is therefore a synergy of means in order to obtain a second technical effect compared to the prior art.

Claims

Claims

1. Method for locking or unlocking a door (P) of a vehicle (V), by a locking / unlocking device (D) on board the vehicle, comprising at least two high-frequency communication transceivers (Txl, Tx2), capable of communicating with a portable user equipment (SD), of which a first transceiver (Txl) is located in the door (P), and a second transceiver (Tx2) is located inside the vehicle (V), the method being characterized in that it comprises the following steps: a. Detection of presence of the user's portable equipment (SD) in a predetermined area (Zl) around the vehicle (V), b. If portable equipment (SD) has been detected, emission of waves between the two transceivers (Txl, Tx2), c. Measurement of a time of flight (TOF1, TOF2) of said waves, d. Comparison between the said time of flight (TOF1, TOF2) measured with a predetermined time of flight (TOF), measured beforehand without any hand (M) near the handle (P), e. Unlocking or locking the door if a result of the comparison is greater than a first threshold (Al), an approach of the user's hand (M) modifying the propagation of the waves between the first (Txl) and the second receiver (Tx2) and increasing the time of flight (TOF1, TOF2).

2. Method of unlocking or locking, according to the preceding claim, characterized in that the door (P) is first equipped with two surfaces identifiable by the user, an unlocking surface (SI) and a locking surface (S2), and in that: a. When the user (U) approaches the unlocking surface (SI), the time of flight (TOF1) is greater than a previously measured time of flight without hands (M) and the unlocking is activated b. When the user (U) approaches the locking surface (S2), the flight time is greater (TOF2) than a previously measured flight time without hands (M) and the ver- rusting is activated.

3. Unlocking or locking method according to the preceding claim, characterized in that if the time of flight (TOF1) is greater than the first threshold (A1) then unlocking is activated, and if the time of flight (TOF2) is greater than the second threshold (A2) then locking is activated.

4. Unlocking or locking method, according to any one of the preceding claims, characterized in that the predetermined time of flight (TOF) has been measured beforehand in the absence of the portable equipment (SD) in the predetermined zone (Zl) around the vehicle (V).

5. Device (D) for locking or unlocking a door (P) of a motor vehicle (V), intended to be embedded in said vehicle, comprising at least two high-frequency communication transceivers (Txl, Tx2) capable of communicating with a portable user equipment (SD), of which a first transceiver (Txl) is located in the door (P), and a second transceiver (Tx2) is located inside the vehicle (V), the device being characterized in that it is further capable of: a. Detecting a presence of the portable user equipment (SD) in a predetermined area (Zl) around the vehicle, b. Controlling the emission of waves between the two transceivers (Txl, Tx2), depending on the detection, c. Measuring a time of flight (TOF1, TOF2) of said waves, d. Compare said measured time of flight (TOF1, TOF2) with a predetermined time of flight (TOF), e.Unlock or lock the door (P) depending on the result of the comparison.

6. Locking or unlocking device (D) according to the preceding claim, characterized in that it also comprises on the door (P) two surfaces identifiable by the user, an unlocking surface (SI) and a locking surface (S2).

7. Locking or unlocking device according to the preceding claim, characterized in that it comprises: a. Means for comparing the time of flight (TOF1) to a first threshold (A1), and b. Means for comparing the time of flight (TOF2) to a second threshold (A2), and in that it is capable of unlocking the door according to a result of comparison with the first threshold (A1) and of locking the door according to a result of comparison with the second threshold (A2).

8. A computer program product, comprising program code instructions for executing the steps of the method according to any one of claims 1 to 4 when said program is executed on a computer.

9. Motor vehicle (V), characterized in that it comprises a locking or unlocking device (D) according to any one of claims 5 to 7.

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