EP0926305B1 - Safety device, in particular for motor vehicle - Google Patents

Description

The present invention relates to a security system, in particular for a motor vehicle.

More particularly, it relates to a system comprising a fixed terminal and a portable object capable of delivering a signal. unlocking at the fixed terminal.

In the example of application envisaged here, the fixed terminal is constituted by the centralized locking / unlocking center of the vehicle, and the portable unit is constituted by a remote control unit for closing and opening the doors of the vehicle remotely. .

The portable object is intended to be carried by an authorized user, in particular the owner of the vehicle. Its function is to deliver, under certain conditions, a locking / unlocking signal to the fixed terminal. This signal is generally emitted by carrier wave (electromagnetic wave or infrared wave).

The expression "fixed terminal" used above to designate, for example, the central locking / unlocking unit on board the vehicle, is obviously a relative expression and must be understood by reference to the portable object.

The locking / unlocking signal delivered by the portable unit generally comprises a fixed or evolving code (that is to say whose value is a function of the number of transmissions previously carried out) which must be recognized as valid by the terminal. fixed to cause the vehicle doors to be locked or unlocked.

The level of security of such a system with regard to the risks of theft is however still imperfect insofar as the mere physical detention of the portable object allows most of the time to cause this unlocking. Thus, if the portable object is lost or stolen, a malicious third party can easily use it to cause the unlocking of the doors of the vehicle and steal objects therein or even steal the vehicle.

The object of the invention is to overcome this drawback of the safety systems of the prior art.

The idea which is the basis of the invention consists in associating the security system with its (or its) authorized user (s), so that only it (s) it (or these) could (s) cause the unlocking of the vehicle doors.

For this, the invention proposes to use means for measuring a biometric signature of the user (s) authorized user (s). Such a biometric signature is for example defined by a fingerprint, the iris of the eye, or an audiometric spectrum of the voice of the authorized user.

The use of such a means of measuring a biometric signature in an identification or authentication function of a natural person is known in the prior art. Thus, we have already imagined the use of a voice recognition module in the fixed terminal to control the locking or unlocking of the vehicle doors to the sound of the voice of the authorized user. In this case, the portable object becomes superfluous, and can advantageously be eliminated. This gives a “hands-free” access system which seems to be the focal point of research and development efforts in this area.

However, such a system may present a risk of accidental unlocking of the vehicle doors, for example if the authorized user inadvertently pronounces a word or a sequence of words capable of causing the doors to be unlocked while he is near the vehicle. If he does not realize it, he can leave his vehicle and leave it unattended while the doors are unlocked.

Document JP-A-01 114 193 discloses a secure voice-activated vehicle door opening system. Three signals are taken into account: a command code triggered by a switch, digitization of the voice, and a code specific to the transmitter, emitted by a code establishment circuit. All of these three signals are transmitted in modulated form to a receiver on the vehicle.

Furthermore, document WO-A-9 515 663 describes a remote control system for a household appliance, such as a garage door, based on a transmission using DTMF coding. DTMF codes come from a numeric keypad or voice input, in the latter case an appropriate conversion.

Finally, the document JP-A-08 270 281 describes an access control system based on a magnetic card, associated with a fingerprint reader. Operation is based on the detection of both a pre-established code and the recognition of the fingerprint.

Another object of the present invention is to propose means making it possible to prevent any untimely unlocking of the vehicle.

• un interrupteur de type furtif formant des moyens de détection d'une intervention active d'un utilisateur produisant un signal d'activation ;
• un moyen de mesure d'une signature biométrique de l'utilisateur produisant un premier signal de mesure ;
• des moyens de génération du signal de verrouillage/déverrouillage produisant le signal de verrouillage/déverrouillage lorsque au moins le signal d'activation et le signal de mesure sont produits dans une fenêtre temporelle déterminée d'une part, et lorsque la signature biométrique mesurée correspond à celle d'un utilisateur autorisé d'autre part.

To this end, the invention provides a security system, in particular for a motor vehicle, comprising a fixed terminal and a portable object capable of delivering to the fixed terminal a signal for locking / unlocking a functional unit such as a vehicle in which the portable object includes:

• a stealth type switch forming means for detecting an active intervention by a user producing an activation signal;
• means for measuring a biometric signature of the user producing a first measurement signal;
• means for generating the locking / unlocking signal producing the locking / unlocking signal when at least the activation signal and the measurement signal are produced in a determined time window on the one hand, and when the measured biometric signature corresponds to that of an authorized user on the other hand.

Thus a measurement of a valid biometric signature is a necessary condition to cause the transmission of the locking / unlocking signal by the portable object. In this way, a malicious third party who would have the portable object could not validly use it to cause the unlocking of the vehicle.

But this condition is not sufficient. In order for the locking / unlocking signal to be generated, active user intervention is still required. In this way it avoids inadvertent unlocking of the vehicle.

The characteristic according to which both of the activation and measurement signals must be validly generated within a determined time window for the locking / unlocking signal to be delivered makes it possible to be free from any problems of order and / or synchronization between the realization of these two events.

In addition, with the invention, the function of the remote control unit associated with the portable object is preserved, so that the current habits of the users are not profoundly modified.

• à la figure 1 : un schéma simplifié d'un système de sécurité pour véhicule automobile;
• à la figure 2 : un exemple d'objet portable selon l'invention;
• à la figure 3 : un exemple de schéma fonctionnel d'un objet portable selon l'invention.

Other characteristics and advantages of the present invention will become apparent on reading the description which follows. This is purely illustrative and should be read in conjunction with the accompanying drawings, in which:

• in Figure 1: a simplified diagram of a security system for a motor vehicle;
• in Figure 2: an example of portable object according to the invention;
• in FIG. 3: an example of a functional diagram of a portable object according to the invention.

In Figure 1, there is schematically shown a functional unit constituted in the embodiment of the invention by a motor vehicle 101. This is equipped with a fixed on-board terminal such as a central locking / unlocking central 102.

The system also includes a portable object 103 such as a remote control unit associated with a vehicle key. In the rest of the description, the portable box is confused with the remote control box or the vehicle key, and these three expressions are used without distinction, unless it is arranged otherwise. This portable box is intended to be worn by an authorized user 104 such as the owner of the vehicle. Other authorized users may also have to use the portable box 103 or another box of the same kind which is more personally assigned to them.

The portable box 103 is intended to deliver, under certain conditions, a locking / unlocking signal SD to the fixed terminal 102. This unlocking signal can be transmitted by carrier wave such as an electromagnetic wave or an infrared wave. In the first case, it may be a radiofrequency signal modulated in amplitude or in phase.

In Figure 2, there is shown a more precise view of the vehicle key according to the invention.

The key 103 conventionally comprises a metal part 12 forming a key insert, as well as a plastic housing 11 forming a head or part for gripping the key. The housing 11 provides a remote control function and for this purpose contains an electronic circuit for the emission of the aforementioned unlocking signal SD.

In a manner known per se, the remote control unit includes means for detecting active user intervention. These means may for example include one or more keys on a keyboard. More simply, these means comprise a switch SW, for example of the push button type, disposed under a first region 13 of the remote control unit 11. This is made of plastic. Due to a reduced thickness or adjacent ribs, the part 13 of the housing can bend under the pressure exerted by the thumb 15 of the user so as to actuate the switch SW contained in the housing 11 (and which, for this reason is shown in broken lines in Figure 2).

According to the invention, the remote control unit 11 further comprises means for measuring a biometric signature of an authorized user of the vehicle. One such means may include a microphone and a voice recognition device for identifying the user's voice. Preferably, however, this means comprises a fingerprint sensor CED disposed inside the housing 11 (and which for this reason is also shown in broken lines in FIG. 2) whose active surface is flush with the surface of the housing 11 of the key head.

Such sensors are now available in the form of monolithic integrated circuits at a price compatible with the nature of the market for security systems for motor vehicles and which are sufficiently precise and reliable and compact for this type of application. One can for example use the sensor offered by the company SGS THOMSON MICROELECTRONICS under the reference STFP2015-50. The active surface of this sensor is less than 2 cm ² . This active surface includes nearly one hundred thousand detection points arranged in a matrix. The sensor delivers digital data in series corresponding to a scan of its active surface. A scan of the entire active surface is performed eight times per second.

In a first possible embodiment, the fingerprint sensor is disposed in a region 14 of the housing 11 which is opposite to the aforementioned region 13 so that the user's index finger 16 is in contact with the part 14 then that his thumb 15 is in contact with the part 13, when the housing 11 is pinched between these two fingers.

However, in a variant, the sensor can also be disposed on the surface of the housing 11 at the aforementioned part 13, so that the thumb 15 of the user is applied against the active surface of the sensor and also exerts through that -this pressure to activate the push button SW on the remote control.

The mechanical installation of the switch SW and the CED sensor in the housing 11 is not limiting and can be carried out in any suitable manner within the reach of those skilled in the art. It will therefore not be described in detail in the present description.

In Figure 3, there is shown a block diagram of the portable object according to the invention. More precisely, it is a functional diagram of the means of the invention included in the portable object.

According to the invention, the portable object comprises means for detecting an active intervention by a user. These means produce an activation signal SA1.

These means include the switch SW, one terminal of which is connected to the positive terminal of a positive voltage source ST1, the negative supply terminal of which is connected to ground. The SW switch is of the stealth type like a push button. These means further comprise a time delay means MS1. The first terminal of the switch SW is connected as has been said above, and its other terminal is connected to the input of the timing means MS1, the output of which delivers the activation signal SA1. This time delay means is for example a monostable time constant circuit T. It has the effect of maintaining the activation signal SA1 in the active state, that is to say in the logic state 1, for a time window determined (corresponding to its time constant T), after closing of the switch SW. Thus, even if the pressure exerted by the user's thumb 15 on the switch SW is stealthy, the activation signal SA1 is maintained in the active state during said time window.

The portable unit also includes a means of measuring a biometric signature of the user which, as mentioned above, is preferably a CED fingerprint sensor. This sensor delivers a measurement signal SM2.

The portable unit further comprises means for generating the unlocking signal SD, the function of which is to produce the unlocking signal when the activation signal SA1 and the measurement signal SM2 are produced in the determined time window T of a part, and when the signature measured corresponds to that of an authorized user on the other hand.

These means are produced in the form of a management circuit comprising a first input E1 for receiving the activation signal SA1 and a second input E2 for receiving the measurement signal SM2 delivered by the sensor CED. The management circuit 20 further comprises a microcontroller M1 comprising a memory DB2. in which the biometric signatures of one or more authorized users are stored (i.e. here the fingerprint of the thumb or index finger, as the case may be, or of any other finger). These signatures can be stored in the form of a binary data matrix. The biometric signatures of each authorized user are stored in separate areas of DB2 memory referenced by a user number. For example, five separate zones can be provided for storing the biometric signatures of five different authorized users corresponding to members of the same family, to each of which is fictitiously associated a user number 1, 2, 3, 4 or 5 respectively.

Preferably, the signal SM2 delivered by the fingerprint sensor CED is a digital signal. The data provided on the second input E2 of unit 20, are therefore directly usable by the microcontroller M1. Otherwise, an analog / digital converter must be provided.

The microcontroller M1 is controlled by a management program. When the data contained in the measurement signal SM2 corresponds to the data stored in one of the five memory zones of the memory DB2 of the microcontroller M1, the latter delivers on an output OUT a signal transmitted to a transmission circuit ER2 to cause the SD unlock signal to be transmitted via, for example, an antenna or an infrared diode.

In order to better illustrate the logical combination of the activation signal SA1 and the measurement signal SM2 within the management unit 20, we have chosen to represent, in FIG. 3, a logic gate PL2 of type ET, the first of which input receives the activation signal SA1 and a second input of which receives the measurement signal SM2. The output of this gate PL2 is connected to an input I1 of the microcontroller M1. The presence of door PL2 is only intended to illustrate one of the conditions. according to the invention so that the unlocking signal is transmitted, namely that the activation signal SA1 and the measurement signal SM2 are generated during a time window T. With the configuration shown, the measurement signal SM2 delivered by the sensor CED can be transmitted on the input I1 of the microcontroller M1 only when the activation signal SA1 is active in logic state 1.

This representation does not, however, imply any tangible limitation as to the practical implementation of the invention insofar as the signals SA1 and SM2 can be transmitted on two separate inputs of the microcontroller M1 to be processed therein in a logical operation of the AND type. Note that the window time T, during which the signal SA1 is maintained in the active state, must at least be equal to the duration of the transmission of the data corresponding to the fingerprint of a user by the measurement signal SM2. A time window of 500 milliseconds is sufficient.

In other possible embodiments of the invention, the portable object also comprises at least one other means of measuring a biometric datum of the user producing another measurement signal. The means for generating the unlocking signal SD then produce the signal SD when the activation signal SA1 and all the measurement signals are produced in the above-mentioned time window T, and when the measured signature corresponds to that of an authorized user and including his fingerprint.

Such other biometric data of the user can be constituted by the arterial pressure measured at the level of his finger. The means for measuring this biometric data then comprises a pressure sensor CPR.

Likewise, another biometric datum of the user can also be constituted by the temperature of his finger. The means for measuring this biometric data then comprises a PTC temperature sensor.

Taking into account one or more of these other biometric data of the user makes it more difficult to attempt fraud consisting in manufacturing an artificial finger (for example made of latex) which is a faithful reproduction of the user's finger authorized.

In FIG. 3, a second logic gate PL3 of the ET type has been schematically represented which receives the measurement signal SM3 delivered by the pressure sensor CPR on a first input, and the activation signal SA1 on a second input. The output of gate PL3 is transmitted to a second input I2 of the microcontroller M1. Similarly, a third logic gate PL4 of the ET type has been schematically represented which receives the measurement signal SM4 generated by the temperature sensor CTP on a first input, and the activation signal SA1 on a second input. The output of the door PL4 is connected to a third input 13 of the microcontroller M1.

In a particular embodiment of the invention, the unlocking signal SD comprises an impersonal code. identifying that of authorized users whose biometric signature has been recognized as valid. This impersonal code can simply consist of the user number 1, 2, 3, 4 or 5 mentioned above. This allows the activation of comfort functions in the vehicle upon reception of the SD signal. Such functions consist, for example, in adjusting the height of the seats, the position of the mirrors, a set temperature for an on-board air conditioning installation, a radio station, etc., at predefined values. corresponding to the usual choices of the user concerned.

Advantageously, it will be noted that it is not the information relating to the biometric signature of the user which is transmitted, but an impersonal number, for example 1, 2, 3, 4 or 5 whose sole function is to identify one of the authorized users among the limited set of these. It is this notion expressed by the adjective "impersonal" used above. There is therefore no risk that the data relating to the biometric signature of an authorized user fall into the hands of a malicious third party who intercepted the unlocking signal SD.

Of course, the unlocking signal SD also includes a vehicle identification code with which the portable object is associated making it possible to associate a determined portable object with a single vehicle.

The structure of the fixed terminal for example constituted by the central locking / unlocking of the vehicle doors is not specific to the invention and can therefore be in accordance with those of the systems of the prior art. At the very least, it is within the reach of the skilled person, and, for this reason, is not described in detail in the present description.

In addition, conventionally, the locking / unlocking signal may also include an evolving code, that is to say a code whose value changes with each transmission. We know that such a code makes it possible to prevent fraud attempts consisting in capturing and recording (with suitable electronic means) the locking / unlocking signal when it is emitted in a normal manner by the authorized user, for the purpose to reproduce it later fraudulently.

Claims (9)

1. Security system, in particular for motor vehicle comprising a fixed station (102) and a portable object (103) that can deliver to the fixed station a locking/unlocking signal (SD) for a functional unit such as a vehicle,
   the portable object (103) comprising:

   - a switch (SW) of furtive type forming means for detecting an active intervention of a user producing an activation signal (SA1);

   - a means for measuring a biometric signature of the user producing a first measurement signal (SM2);

   - means (20) for generating the locking/unlocking signal (SD) producing the locking/unlocking signal (SD) when at least the activation signal (SA1) and the measurement signal (SM2) are produced in a determined time window (T) on the one hand, and when the measured biometric signature corresponds to that of an authorized user on the other hand.
2. System according to Claim 1, characterized in that the means for detecting an active intervention of the user comprise a switch (SW) of push-button type.
3. System according to Claim 1, characterized in that the means for detecting an active intervention of the user comprise a switch of push-button type (SW) and a timing means (MS1) for maintaining the activation signal (SA1) in the active state during the determined time window (T) after the closure of the switch (SW).
4. System according to one of the preceding claims, characterized in that the means for measuring a biometric signature of the user comprises a fingerprint sensor (CED).
5. System according to one of the preceding claims, characterized in that the means (20) for generating the locking/unlocking signal comprise:

   - a first input (E1) for receiving the activation signal (SA1);

   - a second input (E2) for receiving the measurement signal (SM2);

   - a microcontroller (M1) driven by a management program and comprising a memory in which the biometric signatures of one or more authorized users are stored;

   - a circuit (ER2) for sending the unlocking signal (SD).
6. System according to one of the preceding claims, characterized in that the portable object furthermore comprises at least one other means for measuring a biometric datum of the user producing another measurement signal (SM3, SM4) and in that the means for generating the locking/unlocking signal (SD) produce the locking/unlocking signal (SD) when the activation signal (SA1) and all the measurement signals are produced in the determined time window (T) on the one hand and, when the measured signature corresponds to that of an authorized user on the other hand.
7. System according to Claim 6, characterized in that one of the other means for measuring a biometric datum comprises a pressure sensor (CPR).
8. System according to Claim 6 or according to Claim 7, characterized in that one of the other means for measuring a biometric datum comprises a temperature sensor (CTP).
9. System according to one of the preceding claims, characterized in that the unlocking signal comprises an impersonal code identifying the authorized user whose signature has been measured so as to allow the activation of comfort functions in the functional unit.