WO2005109699A1 - Free-hands access and control system for a motor vehicle functions - Google Patents

Abstract

The invention relates to a free-hands system for controlling motor vehicle functions comprising at least one badge (4) and a monitoring system (6) mounted in the vehicle which exchange data for controlling actuators (40) in order to actuate the vehicle functions. The inventive system also comprises means (18, 48, 36) using a transmission channel by a current crossing a body for exchanging data between the badge (4) and the monitoring system in order to be sure that the initiator of the function control of the vehicle is an authorised badge-carrying user.

Description

 Description HANDS-FREE ACCESS AND FUNCTION CONTROL SYSTEM OF A MOTOR VEHICLE

The invention relates to a "hands-free" access system to and for controlling the functions of a motor vehicle.

A “hands-free” access system to a vehicle allows its user to access the vehicle without, for example, having to insert and operate a mechanical key in a lock. Such a system also makes it possible to control functions of a motor vehicle such as the starting function and others still. A “hands-free” access system includes at least one badge and a control system on board the motor vehicle. In this way, the badge holder and the on-board control system exchange data in order to activate the vehicle functions, such as unlocking the doors of said vehicle.

In the state of the art, “hands-free” systems are known in which the on-board control system performs the identification of the badge which is present in its area of influence using radio frequency channels. . If the badge is identified by its number, stored in a writable memory, the on-board control system then activates means for authorizing the control of the functions of the motor vehicle by the holder of the badge.

However, this state of the art encounters two problems which can be penalizing.

According to a first problem, there is no simple solution to ensure that the badge is actually worn by a human wearer. This is particularly the case when the radiofrequency badge of the state of the art is forgotten inside the vehicle. This is also the case when the badge is worn by a first person, but a second person such as a child manipulates without authorization a control interface that only the first person wearing the badge should be able to use. For the description of solutions to this kind of problem, reference is made in particular to document FR-A-2,838,223.

According to a second problem, contactless communications such as those on radio frequency channels are subject to transmission hazards, as is the case when parasites or interference are generated on the chosen channel. There are technical solutions that reduce the risk of the radio frequency channel being cut. Reference is made in particular to document FR - A - 2.839.801.

In another state of the art represented by the document US-A-4,591,854, it has been proposed to use a technique of data transmission by traversing current. the body or TTS (Transmission Through Skin in English). A body object, such as a watch worn on the wrist, has a memory in which an identifier code is entered in advance. The latter can be transmitted from the watch to a receiver, for example in connection with a computer. The body of the user serves as a conductor for the passage of current between these two entities.

The transmission of the code entered in the watch is established only if the badge holder's finger comes into contact with a conductive plate of the receiver associated with the computer.

Unfortunately, such a technique for transmitting signals passing through the body is not adaptable to a “hands-free” access system for the reason that, naturally, it would require the establishment of physical contact between the user and any on-board control system that would use it when, conversely, the “hands-free” access system tends to avoid this contact.

[010] However, the inventor realized that such a transmission by current passing through the body would make it possible to guarantee that the badge is well worn by a person and that this guarantee would make it possible to secure and make access more reliable. to the vehicle and / or the control of other vehicle functions in the context of the use of a “hands-free” access system for a motor vehicle.

[011] Indeed, the present invention provides a simple solution which can be used in very many circumstances to solve the aforementioned problems. It relates to a “hands-free” access and / or command control system for a motor vehicle of the type comprising at least one badge and a control system on board the motor vehicle connected to at least one control peripheral. access and / or vehicle function. According to the invention, such a system comprises means implementing a current transmission channel passing through the body intended for the exchange of data, in the form of current, between the badge and the control system to ensure that the the initiator of the control of the functions of the motor vehicle is a user wearing the badge.

According to another aspect of the invention, the means implementing a current transmission channel passing through the body comprise a TTS communication means on the vehicle comprising a conductive plate, arranged in a housing associated with at least one opening of the motor vehicle and / or a button for starting the motor vehicle, an electrode of which is connected to a reception channel and then to a means for detecting an identification signal emitted by a conductive plate on the badge in order to detect the presence of the bearer of the badge when an order or function of the vehicle is activated.

According to another aspect of the invention, the system also includes means for implementing a low frequency transmission channel intended for the activation of the badge in a zone (Zone_l) near the motor vehicle or in a zone (Zone_2) of the passenger compartment of the motor vehicle which cooperates with the TTS transmission channel in order to detect the presence of the holder of the badge when an command or a function of the vehicle are activated.

According to another aspect of the invention, the system also comprises means for implementing a high frequency transmission channel intended for the identification of the badge, in order to detect the presence of the holder of the badge when an order or a vehicle function are activated.

According to another aspect of the invention, the system also includes means for detecting an approach of an object with a PSU (proximity sensor unit) device, associated with at least one opening of the motor vehicle and / or to a button for starting the motor vehicle to activate the control system which cooperate with the means of communication by current passing through the body in order to detect the presence of the holder of the badge when a command or a function of the vehicle is activated.

According to another aspect of the invention, the means for detecting an approach to an object comprise at least one capacitive sensor (put also and / or one of the infrared red sensors which are Valeo products), for detecting an approach of an object with said peripheral PSU in order to detect an intention to control functions of the motor vehicle such as an unlocking of the openings of said vehicle which cooperates with the means of communication by current passing through the body in order to detect the presence of the holder of the badge when a vehicle control or function is activated.

According to another aspect of the invention, the means for detecting an approach to an object comprise at least one capacitive and / or infrared sensor associated with the start button of the motor vehicle to detect an approach to an object with said peripheral PSU for detecting an intention to control the starting of the motor vehicle which cooperates with the means of communication by current passing through the body in order to detect the presence of the holder of the badge when a command or a function of the vehicle is activated.

According to another aspect of the invention, the system comprises means for detecting contact of an object with a PSU device to detect an intention to control functions of the motor vehicle such as an automatic locking of the opening elements of the vehicle automobile, which cooperate with the means of communication by current passing through the body in order to detect the presence of the badge holder when a command or a function of the vehicle are activated.

According to another aspect of the invention, the means implementing a current transmission channel passing through the body are means implementing a bidirectional transmission channel between the badge and the control system on-board to ensure that the initiator of the control of the motor vehicle functions is an authorized user wearing the badge.

According to another aspect of the invention, the on-board control system cooperates with at least one conductive electrode plate for radiofrequency field emission intended for activation of the badge by detection on the communication channel by current passing through the body receiving the badge, the said electrode plate (plate is unnecessarily restrictive it seems to me) conductive being arranged in relation to the vehicle as on an opening leaf of the vehicle, in particular on a peripheral associated with a opening leaf of a vehicle and / or a vehicle function control member such as the powertrain start member.

[021] According to another aspect of the invention, the badge comprises a conductive plate for transmitting reception of modulated identification signals of the badge and of the control system connected to the means implementing current passing through the body.

[022] According to another aspect of the invention, the badge comprises means for waking up the badge coupled with a remote reception channel for a radio frequency wave for waking up the badge produced under the command of the on-board control system.

According to another aspect of the invention, the badge comprises and / or the on-board control system cooperates with a means of comparing wave characteristics to distinguish a TTS type contact of communication by current passing through the body with an electrode plate conductive and a TTS communication communication by current passing through the body remotely.

Thus, the system according to the invention makes it possible to detect the moment when there is contact with the conductive detection plate of the on-board control system, by apprehending a phase inversion of the received signal.

[025] Therefore, according to the invention, when the system detects a phase inversion and an amplitude jump of the received signal, this indicates that the user arrives / comes into contact with the conductive plate, while if the system detects a phase inversion and a drop in amplitude of the received signal, this indicates that the user is freeing / moving away from the contact of the conductive plate.

The invention will be better understood, and other aims, characteristics, details and advantages thereof will appear more clearly in the explanatory description which follows, made with reference to the appended drawings in which: - Figure 1 illustrates an example cutting out the location areas of a badge for a hands-free system for controlling motor vehicle functions; - Figure 2 illustrates, schematically, an embodiment of the device according to the invention; - Figure 3 schematically illustrates the means implementing a channel transmission by current passing through the body; - Figure 4 illustrates in the form of a flowchart the operation of a hands-free system in accordance with the requirements of the invention; - Figure 5 schematically illustrates an alternative embodiment of a hands-free system in accordance with the requirements of the invention; - Figure 6 schematically illustrates a second alternative embodiment of a hands-free system in accordance with the requirements of the invention.

We will first describe a number of drawbacks and problems encountered in the operation of a “hands-free” access system according to the preamble to the main claim.

In another known embodiment, the “hands-free” access system may include means for detecting the approach of an object, particularly the hand of a user, with one of the handles arranged on each opening of the motor vehicle or with the start button located in the vehicle driving position. In particular, such means include a first capacitive sensor which makes it possible to develop an electrical signal of which at least one parameter (amplitude or phase) changes according to the distance which separates the capacitive sensor from an object on approach. The electrical signal from the capacitive sensor is intended firstly to activate the hands-free system and secondly to detect an intention to control a function. For example, the approach of the user's hand towards the handle of a door is interpreted by the identification system as a user's approach and as the expression of an intention to open. of the relevant opening of the motor vehicle.

In this case, there are many situations in which the electrical signal of the capacitive sensor representative of an approach can be triggered in a wrong way by a jet of water in an automatic washing station, the passage of a pedestrian , a tree leaf, ..., because the hands-free system cannot distinguish false alarms.

In another known embodiment, the hands-free system further comprises means for detecting contact of an object, particularly the hand of a user, with one of the handles disposed on each opening of the vehicle automobile or the motor vehicle start button. In particular, such means include a switch or a second capacitive sensor, the capacity of which varies in contact with an object with a handle of an opening leaf or at the start button. The second capacitive sensor is essentially intended for the detection of an intention of automatic locking. For example, when the user touches a door handle, the value of the capacity of the second capacitive sensor changes and becomes characteristic of a contact. The identification system interprets this change in value capacity such as an intention to lock automatically when, for example, the driver has left an area of control inside the vehicle.

[031] As in the previous case, it is impossible to guarantee in this state of the art that the action which produces the activation of the electric detection signal is caused by the usual user who can give a real locking order.

In another known embodiment, the part on board the vehicle of the hands-free system comprises means for transmitting an interrogation signal transmitted either at low frequency, typically 125 KHz, or at high frequency, typically 433 MHz. The response signal by the badge is transmitted at high frequency at 433 MHz.

In the state of the art, before the execution of one of the abovementioned vehicle access or vehicle function control functions such as starting the powertrain, the identification system is activated when the first capacitive sensor detects the approach of an object.

[034] The identification system then transmits radio frequency signals in order to wake up or activate the badge. Indeed, the different means constituting the badge are not permanently activated to limit energy consumption.

The badge then responds to the identification system with a radio frequency signal intended to confirm its presence in an area close to the motor vehicle or in the passenger compartment, its identifier code and its activation (or alarm clock). The identification system then compares the data received with its own data in memory, in order to authorize or not the control of the functions of the motor vehicle.

[036] Next, the identification system interprets the radio frequency data received as the location of the badge and the detection of the approach of an object with a door handle or the start button to detect an intention to control functions. In the state of the art, to control a function of the motor vehicle, the hands-free system, at first, detects an intention to control on the part of the user, wearing the badge, such as unlocking the doors or the trunk, voluntary locking or starting of the motor vehicle.

[037] For example, the location of the badge near the motor vehicle and the detection of the approach of an object with the handle of the trunk are interpreted by the identification system as an intention to unlock the trunk.

[038] Finally, the identification system then controls, if the badge identifier code is confirmed, the necessary actuators implementing the function desired by the user such as unlocking the doors.

[039] A disadvantage of this state of the art is that the radio frequency signals exchanged between the identification system and the badge can be disturbed by radio frequency noise making the hands-free system inoperative.

Another disadvantage of this state of the art is an involuntary unlocking opening of the motor vehicle by an unauthorized person. In particular, the holder of the badge can be in an area close to the motor vehicle, in which case the badge will therefore be identifiable. An unauthorized person, that is to say without the badge, can thus unlock the doors by operating a handle on one of the doors of the motor vehicle.

[041] Another drawback of this state of the art is that the hands-free system can be easily hacked. In fact, knowing the form of the radiofrequency signals exchanged between the badge and the identification system, it would be possible to produce the radiofrequency signals necessary for unlocking the doors of the motor vehicle and for starting the motor vehicle. An ill-intentioned individual could thus enter the motor vehicle and therefore steal it.

[042] Another drawback of this state of the art is an involuntary unlocking in the presence of external disturbances. Indeed, the first capacitive sensor to detect an approach is sensitive to external disturbances notably produced by water when it rains or during an automatic washing, etc. In such a situation, if the holder of the badge is near the motor vehicle, the hands-free system having identified the presence of the badge near the rear boot, can authorize the unlocking of the boot. When the latter is motorized, it opens automatically. This situation is of course very delicate.

Another drawback of this state of the art is an involuntary locking of the doors of the motor vehicle. This situation can occur when the badge is in an ambiguity zone, that is to say overlapping zones between the location zone in the passenger compartment and the location zone outside the vehicle. The hands-free system may not be able to distinguish one of these areas and may therefore lock the vehicle even though the badge is still present in the passenger compartment.

Another drawback of this state of the art is an involuntary starting of the motor vehicle. For example, the driver is not in the passenger compartment and the badge is in the passenger compartment. A passenger, like a child, can start the motor vehicle. Thus, as long as the badge is present in the passenger compartment, any unauthorized person can start the motor vehicle.

The inventor realized that these drawbacks of the state of the art result either from the function command by an unauthorized person or from an external disturbance.

[046] The inventor realized that it would be very advantageous to integrate a device with current hands-free systems which would make it possible to ensure that the initiator of the command of the functions is indeed an authorized person, c 'is to say a user wearing the badge on him. Only the means used in hands-free systems current, as the radio frequency means and the various capacitive sensors, do not allow the realization of such a system.

[047] In another state of the art, devices have already been described using signal transmission by currents passing through the body TTS (English acronym for Transmission Through Skin). Generally, such devices are used to authorize access to a room, such as a hotel room, or to a safe by an authorized person carrying an electronic circuit generating the current passing through the body. However, the devices implementing such a transmission are permanently activated and consume a lot of energy.

[048] The inventor therefore had the idea not only of integrating a current transmission passing through the body into current hands-free systems for a motor vehicle but also of activating the means implementing this TTS transmission only when the system hands-free must ensure that the badge is worn by an authorized person in order to limit energy consumption. The “hands-free” access system of the invention therefore comprises activation means making it possible to wake up the electronic circuits of the badge.

[049] FIG. 1 represents an exemplary embodiment of a “hands-free” access system implementing the invention. The “hands-free” access system therefore mainly comprises an on-board control system and at least one badge. The badge is worn by a driver who is present near the on-board control system on board vehicle V. If the access system is built on the basis of a radio frequency system, as already mentioned above top, In the embodiment, the on-board control system is connected to at least three types of antennas: • A first type of low-frequency LF transmitting antenna posted on a plate associated with each opening of the vehicle; • A second type of low-frequency BF antenna posted near the vehicle's starting device, at the driver's seat; • A third type of HF high-frequency antenna, for example posted on the roof or associated with the vehicle's roof antenna.

The “hands-free” access system of this exemplary embodiment of the invention essentially comprises: - an on-board control system 6 on board the vehicle V; - at least one badge 4 intended to be worn by an authorized user.

[051] The badge 4 of the invention most often consists of a small plate, of the type of a credit card or a box that is not much thicker. The badge 4 comprises in a first embodiment of the “hands-free” access system of the invention, only the TTS communication means are placed in the badge using currents crossing the body of the badge holder, as will be described later.

[052] In other embodiments of the “hands-free” access system of the invention, the badge 4 also includes RF radiofrequency communication means which are intended to communicate with the on-board control system 6 and which cooperate with the TTS communication means of the badge 4 as will be described later.

[053] The on-board control system 6 is connected by known means to specific peripherals which are of three types: - approach detection devices and / or remote control, for example based on a high frequency HF antenna; - PSU peripherals linked to the functions of access to the passenger compartment of the vehicle and most often associated with an opening of the vehicle such as a door PI to P4 and a rear trunk C; - DEM peripherals linked to vehicle-specific functions such as the powertrain start function.

[054] For reasons of simplicity, there is shown a single PSU type unit attached to the door PI and connected by an electrical connection 6-1 to the control system 6 on board the vehicle V. However, preferably, each opening P2, P3, P4 and C has its own PSU device which is connected by an analog link. 6-2, 6-3, 6-4 and 6-C to the control system 6.

[055] Peripherals of the PSU type include means by which the holder of the badge can intervene on manual control interfaces such as a capacitive or infrared sensor or a switch to trigger a locking or unlocking of the opening elements. More generally, they include sensors capable of detecting an approach or an intention to activate a vehicle function.

[056] In a first embodiment which will be detailed below, the “hands-free” access system of the invention may comprise only peripherals of the PSU type associated with the opening elements of the vehicle V. Each peripheral or PSU unit associated with an opening PI, P2, P3, P4 or C of the vehicle V then also includes TTS means not shown in FIG. 1 which make it possible to establish a dialogue between the badge 4 and the on-board control system 6 on the single track TTS.

[057] In a second embodiment, in which badge 4 and on-board control system 6 comprise and / or cooperate with radio frequency means, the “hands-free” access system makes it possible to distinguish three types of zones near the motor vehicle V: - A type of zone Zone_l for which the badge holder will be located at a distance from the vehicle, that is to say that it will be determined as being in a phase of approaching or moving away from the motor vehicle V by means of the HF approach detection device; - A type of zone Zone_2 for which the badge holder will be located in the passenger compartment of the motor vehicle, particularly an area close to the driving position, particularly by a DEM type device; - A type of zone Zone_Z3 particularly near the doors PI to P4 and the trunk C by means of a peripheral of the PSU type.

It is noted that each of the three types of zones have overlap or ambiguity zones, particularly the zone shown in the drawing where the zones Zone_l and Zone_2 overlap or overlap. In fact, the zone Zone_2 not being strictly delimited by the passenger compartment of the motor vehicle, phenomena of overflow from said zone may appear.

The zones Zone_l and Zone_2 are reserved for the exchange of radio frequency data between a badge 4 and a control system 6 on board the motor vehicle V. The exchange of radio frequency data allows the functions: - activation of the badge 4; - identification of badge 4; - location of the badge 4.

Referring now to Figure 2 in which is shown an embodiment of the second embodiment of the invention in which cooperate radio frequency means and TTS means implementing currents passing through the body of the carrier of the badge 4 are detailed. To achieve a system according to the first form of the invention, those skilled in the art can eliminate most of the means used in radio frequency communications.

[061] To implement a radio frequency channel, the control system 6 comprises means 22, 24, 26 for transmitting low-frequency signals, particularly a low-frequency transmission antenna 22 which transmits in the zone Zone_l, a low-frequency transmission antenna 24 which transmits in the zone Zone_2 and a processing unit 26 of the low-frequency signals to be transmitted.

[062] The control system 6 further comprises means 28, 30 for receiving high-frequency signals, particularly a high-frequency reception antenna 30 and a processing unit 28 for the high-frequency signals received.

The badge 4 includes means 8, 12 for receiving low-frequency signals emitted by the control system 6, particularly a low-frequency antenna 8 and a processing unit 12 for low-frequency signals emitted by the system of control 6.

The badge 4 includes means 10, 14 for transmitting high-frequency signals to the control system 6, particularly a high-frequency antenna 10 and a processing unit 14 for the high-frequency signals to be transmitted.

[065] Once the control system 6 is activated by means indicated below in the description, the low-frequency antennas 22 and 24 periodically transmit low-frequency signals respectively in the zones Zone_l and Zone_2.

[066] The low-frequency signals are emitted by a BF antenna associated with the vehicle and supplied by a suitable modulator of the control system 6. They carry data comprising an identifier code of the control system 6, where appropriate, an identifier code of the badge 4 and the useful part of the transmission, here an activation (or wake-up) datum of the badge 4.

The badge 4 includes, as is known, a source of electrical energy (not shown) and an electronic processor 16. The processor 16 of the badge 4 manages the communications of both TTS means and RF means when they are implemented. In order to limit its energy consumption, the processor places the badge 4 in a so-called "standby" mode where it is only able to receive the low-frequency signals emitted by the control system 6. The "standby" mode is activated when the badge 4 is no longer located in the zones Zone_l and Zone_2 or when the user no longer manually controls the badge 4, particularly when the latter includes a user interface for remote control of vehicle functions.

[068] After receiving the low-frequency signals, the processor or processing unit 16 of the badge 4 compares the identifier code of the control system 6 with a reference value contained in a memory of the badge 4. If the control system 6 is recognized by the processing unit 16, the badge 4 transmits a high-frequency acknowledgment signal to the control system 6 intended to warn it of its activation. The high-frequency acknowledgment signal in particular carries data comprising a badge identifier code 4, where appropriate the identifier code of the control system 6 and the message itself, namely the acknowledgment (or confirmation) of the activation. badge 4.

[069] The badge 4 is thus activated and the on-board control system 6 has identified it. In order to keep the badge 4 in an activated state, the badge 4 is periodically located by the RF means associated with the on-board control system 6 in order to ensure that it is always located in one of the zones Zone_l to Zone_3 for which activation of the badge 4 is of interest, particularly for controlling the functions of the motor vehicle.

[070] Thus, the control system 6 periodically transmits low-frequency maintenance signals to the badge 4 intended to interrogate the badge 4 to ensure its presence in one of the zones.

[071] The non-reception of a high-frequency presence confirmation signal, beyond a predetermined time interval, is interpreted by the control system 6 as an exit from the badge for zones Zone_l and Zone_2. The badge 4 is thus deactivated. [072] The location of the badge 4 therefore makes it possible to maintain the badge 4 in an activated state and to improve the detection of intention to control functions. [073] Figure 2 schematically illustrates an embodiment of an access system 2 comprising a badge 4, a control system 6 and a PSU device 50. [074] In particular, the PSU device 50 is associated with a handle door or trunk or the start button of the motor vehicle located in the driving position. [075] Thus, according to the embodiment described in FIG. 1, the access system 2 comprises a peripheral PSU 50 for each door PI, P2, P3, P4, for the boot C and for the start button DEM ( see figure 1). The PSU device 50 comprises a means of detection, like a conductive plate 48, of a modulated identification signal emitted by the badge 4 via the transmission channel by current passing through the body. The PSU device 50 includes means such as a first capacitive proximity sensor 44 for detecting an approach of an object, particularly the hand of a user, with said device PSU 50. The value of the capacity of the capacitive sensor 44 proximity is variable and varies depending on the distance between the object and the. PSU 50 device. [078] The PSU 50 device comprises means such as a second capacitive contact sensor 46 for detecting contact of an object, particularly the hand of a user, with said PSU 50 device. The value of the capacity of the capacitive contact sensor 46 is variable and takes on distinct values, one in the event of contact and another in the event of non-contact. The badge 4 includes: - means (8,12) for receiving low-frequency signals transmitted by the control system 6 of the type a low-frequency reception antenna 8 and a low-frequency signal processing unit 12; - Means (10,14) for transmitting high frequency signals to the control system 6 of the type a high frequency transmitting antenna 10 and a high frequency signal processing unit 14; a means 20, such as a conductive plate, intended for the implementation of proximity and contact detection with the peripheral PSU 50. The conductive plate generates a modification of the value of the capacity of the capacitive sensors when the distance which separates from the device PSU 50 decreases; a TTS-Badge processing unit 18 of modulated identification signals to be transmitted to the control system 6 via a current transmission channel passing through the body, said unit comprising a conductive plate (not shown) and modulating means (not shown); a processor or control and command unit 16 intended to control and command the badge 4.

The control system 6 comprises: - means (28,30) for receiving high-frequency signals transmitted by the badge 4 of the type a high-frequency reception antenna 28 and a high-frequency signal processing unit 30; - Means (22, 24, 26) for transmitting low-frequency signals to the badge 4 of the type a low-frequency transmission antenna 24 in the passenger compartment, a low-frequency transmission antenna 22 in an outside area near the motor vehicle and a low frequency signal processing unit 26; a detection unit 34 intended for the implementation of proximity and contact detection with the peripheral PSU 50. According to the values of the measured capacities of the capacitive sensors 44 and 46, the detection unit 34 is able to know how to determine if an object is near or in contact with the PSU 50 device; a TTS-access processing unit 36 of the modulated signals emitted by the badge 4 via the current transmission channel passing through the body, said unit comprising demodulation means (not shown); a control and command unit 32 intended to control and command the control system 6; - A microcontroller 38 for controlling actuators 40 of the type of means for unlocking the various doors of the vehicle, means for locking the doors of the vehicle and means for starting the vehicle.

[081] In one embodiment, the low-frequency antennas 22 and 24 are replaced by low-frequency antennas, each being associated with a PSU device 50. Thus, the low-frequency antennas associated with the openings PI, P2, P3 , P4, C enable the badge 4 to be activated near the motor vehicle, particularly towards an opening, and the low-frequency antenna associated with the start button makes it possible to activate the badge 4 in the passenger compartment of the motor vehicle.

[082] We will now briefly explain, with reference to Figure 3, the constitution of the communication channel with currents passing through the body. A badge 4 according to the invention includes the already known resources making it possible to establish the two radiofrequency communication channels. The badge 4 of the invention then comprises at least one electrode preferably in the form of a conductive plate 58 intended to come into contact with a part of the body of the person wearing the badge 4, for example when the badge is held in the hand or even when it is placed in a pocket of a garment worn by the badge holder. The conductive plate 58 is inside the badge 4 connected to the output of a modulation circuit 54,56 which permanently produces a modulation signal established on the basis of a local carrier, for example sinusoidal with a frequency included between 5 and 100 kHz and on the basis of identification codes read from a memory register MEM integrated into the badge 4. Of course, the present invention does not require that the badge 4 be made up of a single object. 11 may include several separate objects, for example if the badge part 4 implementing the communication resource by currents passing through the body is integrated into another object in contact with the body. [083] When the badge holder places his hand or finger on an electrode or conductive plate 48 associated with the peripheral PSU 50, a current passing through the body is established between the conductive plate 58 of the badge 4 and the associated conductive plate 48 to the peripheral PSU 50. This current passing through the body carries the modulation signal generated by the badge 4 which is then received on a TTS-access processing unit 36, integrated into the control system 6 on board the vehicle. Such a TTS-access processing unit 36 includes a detection circuit 62 whose input is connected to the conductive plate 48 associated with the PSU device 50 and whose output is connected to a demodulation circuit 64 which extracts the code word d 'identification which is then provided to a first input of a comparator 66 of code words, another input of which is connected to a memory 11 scrolling through a table of authorized codes, particularly the different identifier codes of authorized badges. If the comparison is positive, the TTS-access processing unit 36 to the monitoring and control unit 32 provides a signal identifying the badge 4 detected and identifying the zone, namely zone Zone_l or zone Zone_2, in which the badge holder 4 has been detected as physically touching a part of the vehicle. [084] Figure 4 illustrates in the form of a flowchart the operation of a hands-free system 2 in accordance with the requirements of the invention. [085] In a first step, the hands-free system is activated 2. The activation of the hands-free system 2 comprises: - a step of awakening the control system 6 by detecting an approach (or proximity) of a object, particularly the hand of a user, with one of the boxes 50. Proximity detection with the PSU device 50 is performed when the value of the capacity of the first capacitive proximity sensor 44 becomes characteristic of proximity to said object PSU device 50. The detection unit 34 compares the value of the capacity measured with a reference threshold. When this value becomes greater than the threshold, the unit the unit detection 34 interprets it as proximity detection and emits a signal representative of proximity detection to the monitoring and control unit 32 which activates the means (28,30) implementing the radiofrequency transmission. Of course, the threshold is defined according to the sensitivity which it is desired to grant to the capacitive sensor. a step of waking up the badge 4 by transmitting low-frequency signals to the badge 4 via the low-frequency antenna 22 or the low-frequency antenna 24, said signals being of the type comprising data of the type including the identifier code of the badge 4, the identifier code of the control system 6 and the subject of the signal, namely the awakening (or activation) of badge 4; a step of acknowledgment (confirmation) of the activation of the badge 4 which transmits to the control system 6 via the high-frequency antenna 10 a high-frequency signal comprising in particular data of the type the identifier code of the badge 4 intended to be recognized by the control system 6.

[086] Of course, if the control system 6 does not recognize the identity of the badge 4, the control system 6 prohibits any control of the functions of the motor vehicle.

[087] As we have seen previously, L the control system 6 also maintains the badge 4 in an activated state by transmitting to the badge 4 maintenance low frequency signals to which the badge 4 responds by transmitting high signals - frequency of confirmation of its presence in the Zone_l zone or the Zone_2 zone.

[088] Thus, the function of this first step is not only the activation of the hands-free system 2, but also the identification of the badge 4 and the maintenance of the badge 4 in an activated state by monitoring the location of the badge 4.

[089] In a second step, the hands-free system 2 detects an intention to control a function of the motor vehicle such as unlocking the doors, unlocking the trunk, voluntarily locking the doors of the vehicle and starting the vehicle.

[090] In particular, the detection unit 34 intended for the implementation of proximity detection and of contact with a PSU device 50 includes means for detecting which of the capacitive proximity sensors 44 is responsible for detecting an approach to an object, particularly the hand of a user, with one of the housings 50.

[091] Thus, when the detection unit 34 detects that a capacitive proximity sensor 44, disposed in one of the boxes 50 of the doors PI, P2, P3 or P4, is responsible for the detection, it transmits to the 'control and command unit 32 a signal representative of an intention to unlock the doors of the motor vehicle.

[092] When the detection unit 34 detects that the capacitive sensor 44, disposed in the peripheral PSU 50 of the trunk C, is responsible for the detection, it emits towards the control and command unit 32 a signal representative of an intention to unlock the trunk of the motor vehicle.

When the detection unit 34 detects that a capacitive proximity sensor 44, placed in the PSU device 50 of the start button, is responsible for the detection, it transmits to the control and command unit 32 a signal representing an intention to start the motor vehicle.

[094] To detect an intention of automatic locking, the hands-free system 2 comprises means (not shown) for detecting the opening and closing of an opening of the motor vehicle of the door and means type (not shown) to detect the passage of the badge holder 4 from zone Zone_2 to zone Zone_l with a view to detecting the exit of the badge holder 4 from the passenger compartment. Thus, the simultaneous detection of the opening and closing of an opening and of the passage of the badge holder from one zone to another is intended to be interpreted as an intention of automatic locking. In addition, to confirm the intention of automatic locking, the control system 6 detects contact of an object, particularly the user's hand, with the PSU device 50 of one of the doors PI, P2, P3, P4 via the second capacitive contact sensor 46. The detection unit 34 compares the value of the capacitance of the capacitive contact sensor 46 with a reference value characteristic of a contact.

[095] If the contact of an object with the PSU device 50 is not detected, the control system 6 abandons the automatic locking. The location of the badge 4 also makes it possible to invalidate or confirm the intention of a function command.

[096] In a third step, the control system 6 activates the means 18, 48, 36 implementing the current transmission channel passing through the body in order to ensure that the initiator of the vehicle function control is the holder of badge 4, that is to say an authorized person.

Advantageously, when an approach of an object with the peripheral PSU 50 is detected and an error has appeared during the exchange of the radiofrequency signals, such as the low-frequency signals emitted by the control system 6 and / or the high-frequency signals emitted by the badge 4 during the first step, the control system 6 automatically activates the means 18, 48, 36 implementing the transmission by current passing through the body. Radio frequency noise is generally responsible for an error in the exchange of radio frequency data for the location and / or identification of the badge 4.

[098] Transmission by current through the body is established only if the conductive plate of the badge 4 and the conductive plate of the control system 6 are simultaneously in contact with a body part of the user, wearing the badge. The object of this exchange is the identification of the badge 4 by the control system 6. The modulated identification signal emitted by the badge 4 thus comprises data of the type including the identifier code of the badge 4, the identifier code of the control system 6 and the object of the signals, namely identification.

[100] The control system 6 compares the identifier code of the badge 4 with a reference value contained in a memory to ensure that the identifier code received indeed corresponds to a known code and therefore to ensure that the initiator of the function command is indeed the holder of the badge 4, that is to say an authorized person.

[101] An interruption in the transmission and the control system 6 prohibits the control of vehicle functions until the user tries again.

[102] Of course, if the badge identifier code 4 is not recognized by the control system 6, the control system 6 prohibits the control of the vehicle functions.

[103] In a fourth step, the control system 6 controls the relevant function of the motor vehicle. In particular, the control and command unit 32 transmits to the microcontroller 38 a signal representative of the detected function command. The microcontroller 38 then controls the actuators 40 which are suitable either for locking or unlocking the doors, or for unlocking the boot or when starting the vehicle.

[104] Advantageously, the radiofrequency signals exchanged between the badge 4 and the control system 6 are encrypted in order to strengthen the protection against piracy.

[105] We will now describe two alternative embodiments of a hands-free system which use a current transmission channel passing through the body to ensure that the initiator of the control of the functions of the motor vehicle is an authorized person.

[106] In a first alternative embodiment, the invention proposes a hands-free system 70, illustrated in FIG. 5, identical to that described above with the difference that it does not include the means intended for the implementation of '' a high-frequency transmission channel between a badge 72 and a control system 74.

[107] Consequently, the exchange of radiofrequency signals between the badge 72 and the control system 74 no longer has the function of identifying the badge 72 and maintaining (or maintaining) the badge 72 in an activated state. In particular, the radiofrequency signals emitted by the control system 74 only have the function of waking up (or activating) the badge 72 when the badge holder enters one of the zones Zone_l or Zone_2.

[108] Thus, only the TTS means of transmission by current passing through the body allow the identification of the badge 72, in addition to their main function.

[109] The hands-free system also includes a housing 102-104-106 identical to the PSU 50 device described in Figure 2. [110] The housing 102-104-106 thus comprises: - a first capacitive proximity sensor 102; - a second capacitive contact sensor 104; - a conductive detection plate 106. [11 1] The badge 72 comprises: - means (76,78) for receiving low-frequency signals transmitted by the control system 74 of the type a low-frequency reception antenna 78 and a low-frequency signal processing unit 76; a means 82, such as a conductive plate, intended for implementing proximity and contact detection with the housing 102-104-106. The conductive plate generates a modification of the value of the capacity of the capacitive sensors when the distance which separates it from the housing 102-104-106 decreases; a TTS-badge 80 processing unit for modulated signals to be transmitted to the control system 74 via a current transmission channel passing through the body, said unit comprising a conductive plate (not shown) and modulation means (not shown) ; a control and command unit 84 intended to control and command the badge 72.

[112] The control system 74 comprises: - means (86,88,90) for transmitting low-frequency signals to the badge 72 of the type a low-frequency transmitting antenna 86 in the passenger compartment, an antenna d low frequency transmission 88 in an outdoor area near the motor vehicle and a low frequency signal processing unit 90; - A detection unit 92 intended for the implementation of proximity and contact detection with the housing 102-104-106. According to the values of the measured capacities of the capacitive sensors 102 and 104, the detection unit 92 is able to know if an object is near or in contact with the housing 102-104-106; a TTS-access processing unit 94 of the modulated identification signals emitted by the badge 72 via the current transmission channel passing through the body, said unit comprising demodulation means (not shown);

a control and command unit 96 of the control system 74; a microcontroller 98 for controlling actuators 100 of the type of means for unlocking the various doors of the vehicle, means for locking the doors of the vehicle and means for starting the vehicle.

[113] This embodiment has an economic advantage since means have been eliminated.

[114] In a second variant embodiment, the inventor proposes a hands-free system 110, illustrated in FIG. 6, identical to the previous ones except that it no longer comprises means implementing radio frequency transmission, it ie low-frequency transmission and high-frequency transmission.

[115] The hands-free system 110 always includes a badge 112, a control system 114 and a PSU device 116.

[116] An essential feature of such a hands-free system 1 10 is that the transmission by current passing through the body is here bidirectional in order on the one hand to wake up (or activate) the badge 112 and on the other hand to put in identifies the badge 112 and the control system 114.

[117] The peripheral PSU 1 16 is identical to the peripheral PSU 50 described in FIG. 2 and has the same characteristics.

[118] The peripheral PSU 1 16 thus comprises: - a first capacitive proximity sensor 118; - a second capacitive contact sensor 120; - a conductive detection plate 122. [119] The badge 112 comprises: - a means 124, such as a conductive plate, intended for implementing proximity and contact detection with the peripheral PSU 1 16. The conductive plate generates a change in the value of the capacity of the capacitive sensors when the distance which separates it from the housing 116 decreases; a TTS-badge processing unit 126 of the signals exchanged via the current transmission channel passing through the body, said unit comprising a conductive receiving reception plate 128, means 130 for demodulation modulation; a unit 132 for monitoring and controlling the badge 112. [120] The control system 114 comprises: a detection unit 134 intended for implementing proximity detection and contact of an object with the housing 116; a TTS-access processing unit 136 for the signals exchanged between the badge 112 and the control system 114 via the current transmission channel passing through the body, said unit comprising means 138 for demodulation and modulation, and means 140 for comparison wave characteristics of modulated signals; a control and command unit 142 of the control system 114; - A microcontroller 144 for controlling actuators 146 of the type of means for unlocking the various doors of the vehicle, means for locking the doors of the vehicle and means for starting the vehicle.

[121] To limit the energy consumption of the hands-free system 110, the hands-free system 110 is by default in a mode called "standby". In particular, the means 122, 136, intended for the implementation of the current transmission channel passing through the body, are deactivated.

[122] Thus, when approaching a body part of a user to a PSU device 1 16, the PSU system 118, 124, 134 detects, thanks to the capacitive proximity sensor 118, the approach of said body part .

[123] The PSU system 118, 124, 134 emits a signal representative of proximity detection towards the monitoring and control unit 142 which activates the means 122, 136 implementing the transmission channel by current passing through the body .

[124] In addition, the PSU system 118, 124, 134, by virtue of proximity detection as already described, detects an intention to control the function of the motor vehicle associated with the housing 116 for which the PSU system 118, 124, 134 detected an approach.

[125] To wake up the badge 112, it has been found that, even without the person wearing the badge 1 12 being in contact with the housing 116, the conductive plate 122 of the control system 114 itself radiates a radiofrequency field based on a modulated identification signal. The conductive plate 122 then plays the role of a radiofrequency reception transmit antenna. The invention is based on the use of this radio frequency field to activate the badge 112. Thus, when the control system 1 14 is activated, the conductive plate 122 emits a radio frequency field based on a modulated identification signal comprising type data including the badge identifier code 112 and the control system identifier code 114.

[126] The conductive plate 128 of the badge 1 12 receives the radio frequency field which activates the badge 112, provided that the identifier code of the control system 114 is recognized.

[127] Only, the conductive plate 128 of the badge 112 also radiates and the conductive detection plate 122 necessarily receives this radiofrequency wave.

[128] The TTS-access processing unit 136 can thus demodulate the modulated remote identification signal and therefore the badge identifier code 112, which of course is not desirable in accordance with the requirements of the invention if the '' we want to ensure that the initiator of the function command is indeed the bearer of the badge.

[129] Thus, the hands-free system 110 includes a means for distinguishing a situation of identification of the badge holder according to whether its holder touches or not the conductive detection plate for the control system.

[130] The TTS-access processing unit 136 comprises a comparator of wave characteristics of signals, particularly a phase comparator.

[131] The TTS-access processing unit 136 further comprises a high-frequency antenna for receiving high-frequency signals emitted by the badge due to the radiofrequency radiation from the conductive plate 128.

[132] Thus, in the absence of contact of a body part of the holder of the badge with the box, the reception part can demodulate an identification code "remotely". Such a system is thus able to implement a “contact” detection mode and a “remote” detection mode.

[133] Thus, the invention is based here on the distinction between these two detection modes. However, the two aforementioned detection modes are distinguished by a difference in wave characteristics.

[134] Indeed, the radiation modulation signal is 180 ° out of phase with respect to the contact modulation signal. Thus at an instant t, the instantaneous amplitudes of the modulation signals are in phase opposition.

[135] The phases of the recovered signals are therefore compared using the wave characteristics comparator 140 as a phase comparator. Following this comparison, the TTS-access processing unit 136 assesses whether the badge holder detection mode is a “in contact” detection mode or a “remote” detection mode of the conductive plate 122 depending on whether the two signals are in phase (case of non-contact) or in phase opposition (case of contact). Of course, other phase laws or other wave characteristics than the phase are used according to the invention.

[136] The control system 1 14 thus takes into account the identifier code of the badge 112 only if the reception part detects real contact between a body part of the holder of the badge and the conductive plate 122 of the reception part.

[137] As long as the transmission by current passing through the body is not established, that is to say when the body part of the user is not simultaneously in contact with the badge 112 and the housing 116, the system of control 114 prohibits any function command.

[138] Once the user, wearing the badge, places his hand on the box, the processing unit 136 emits towards the badge 112 a modulated identification signal comprising an identifier code of the badge 112, an identifier code of the control system 114 and the object of the signal such as the identification of the badge.

[139] The processing unit 126 of the badge demodulates, by means of demodulation 130, the modulated identification signal received and then transmits the various identifier codes to the control and command unit 132 of the badge. [140] The control and command unit 132 compares the identifier codes of the badge and of the control system respectively with a first and second reference values.

[141] If the identifier codes are correct, that is to say recognized, the processing unit 126 emits a modulated signal (via the modulation unit) intended to confirm the identification of the control system 1 14, the activation of the badge 112 and the location of the badge 1 12. The modulated module signal transmitted comprises in particular the identifiers of the badge 112 and of the control system 114.

[142] The TTS-access processing unit 136 detects, thanks to the conductive detection plate 122, the modulated signal and in the same way as previously compares, after demodulation, the identifier codes with reference values. If the identifier codes prove to be correct, the control system 114 authorizes the control of functions of the motor vehicle.

[143] In particular, the control and command unit 142 transmits to the microcontroller 144 a signal representative of the detected function command. The microcontroller 144 then controls the actuators 146 adapted either for locking or unlocking the doors, or for unlocking the trunk or for starting the vehicle.

Claims

claims “Hands-free” access and / or function control system of a motor vehicle of the type comprising at least one badge (4) and a control system (6) on board the motor vehicle connected to at least one access control device and / or a vehicle function (PSU, BF, RF, DEM), characterized in that it comprises means (TTS) implementing a transmission channel through current the body intended for the exchange of data, in the form of current, between the badge (4) and the control system (6) to ensure that the initiator of the control of the functions of the motor vehicle is a user wearing the badge (4). [002] System according to claim 1, characterized in that the means (18, 48, 36) implementing a transmission channel by current passing through the body comprise a means (48) of TTS communication on the vehicle comprising an electrode plate (electrode would be better the plate form is not essential and does it not risk introducing a restriction to the concept? true for the rest of the document) conductive (48), arranged in a housing (50) associated with at least one opening of the motor vehicle and / or to a button for starting the motor vehicle, an electrode of which is connected to a reception channel (62) and then to means (64, 66) for detecting an identification signal emitted by a conductive plate (58) on the badge (4) in order to detect the presence of the badge holder (4) when a command or a function of the vehicle are activated. [003] System according to claim 2, characterized in that it also comprises means (8, 12, 22, 24, 26) for implementing a low-frequency transmission channel intended for the activation of the badge (4 ) in a zone (Zone_l) near the motor vehicle or in a zone (Zone_2) of the passenger compartment of the motor vehicle which cooperates with the TTS transmission channel in order to detect the presence of the badge holder (4) when an order or a vehicle function is activated. [004] System according to any one of claims 2 or 3, characterized in that it also comprises means (10, 14, 28, 30) for implementing a high-frequency transmission channel intended for identification of the badge (4), in order to detect the presence of the holder of the badge (4) when a command or a function of the vehicle is activated. [005] System according to any one of claims 2 to 4, characterized in that it also comprises means (20, 34, 44) for detecting an approach of an object with a PSU device (50), associated with at least one opening of the vehicle motor vehicle and / or a motor vehicle start button to activate the control system (6) which cooperate with the means (TTS) in order to detect the presence of the badge holder (4) when an order or a function of the vehicle are activated. [006] System according to claim 5, characterized in that the means (20, 34, 44) for detecting an approach to an object comprise at least one capacitive sensor (or an infrared sensor or more generally any sensor as a captive sensor or an infrared sensor capable of detecting the approach or the intention to activate the function) (44), for detecting an approach of an object with said PSU device (50) in order to detect an intention to control the motor vehicle functions such as unlocking the openings (PI - P4, C) of said vehicle which cooperates with the means (TTS) in order to detect the presence of the holder of the badge (4) when a command or a function of the vehicle are activated. [007] System according to claim 5, characterized in that the means (20, 34, 44) for detecting an approach to an object comprise at least one capacitive approach sensor (idem 6 for other forms of sensors) (44) associated with the motor vehicle start button for detecting an approach of an object with said PSU device (50) for detecting a motor vehicle start control intention which cooperates with the means (TTS) in order to detect the presence the bearer of the badge (4) when an order or a function of the vehicle is activated. [008] System according to any one of claims 2 to 4, characterized in that it comprises means (20, 34, 46) for detecting contact of an object with a PSU device (50) to detect an intention to control functions of the motor vehicle such as an automatic locking of the doors of the motor vehicle, which cooperate with the means (TTS) in order to detect the presence of the holder of the badge (4) when a control or a function of the vehicle are activated . [009] System according to any one of the preceding claims, characterized in that the means (TTS) implementing a current transmission channel passing through the body are means (122, 126, 136) implementing a transmission channel bidirectional transmission between the badge (4; 112) and the on-board control system (6; 114) to ensure that the initiator of the control of the motor vehicle functions is an authorized user wearing the badge (4). [010] System according to claim 9, characterized in that the on-board control system (6; 114) cooperates with at least one conductive plate (electrode?) (122) for emitting radiofrequency fields intended for activating the badge (112) by detection on the reception TTS channel (128) of the badge (4; 112), said conductive plate (122) being arranged in relation to the vehicle as on an opening of the vehicle, in particular on a peripheral (PSU). [011] System according to any one of claims 9 or 10, characterized in that the badge (4; 112) comprises a conductive plate (128) for transmitting and receiving modulated identification signals of the badge (1 12 ) and the control system (114) connected to the means (TTS) implementing current passing through the body. [012] System according to one of claims 10 or 1 1, characterized in that the badge (4; 112) comprises means for awakening the badge coupled with a remote reception channel of a radio wave wake up badge produced under the control of the on-board control system (6; 122). [013] System according to claim 12, characterized in that the badge (4; 122) comprises and / or the on-board control system (6; 114) cooperates with a means for comparing wave characteristics to distinguish a TTS type contact with a conductive plate (122) and a remote TTS transmission.