GB2291238A

GB2291238A - Anti-theft system

Info

Publication number: GB2291238A
Application number: GB9514195A
Authority: GB
Inventors: Siegfried Reinhardt
Original assignee: Siemens AG; Siemens Corp
Current assignee: Siemens AG; Siemens Corp
Priority date: 1994-07-13
Filing date: 1995-07-12
Publication date: 1996-01-17
Anticipated expiration: 2015-07-12
Also published as: FR2722461A1; DE4424735A1; DE4424735C2; GB2291238B; GB9514195D0

Description

2291238 ANTI-THEFT SYSTEM The invention relates to an anti-theft system

for an object, in particular for a motor vehicle.

In known anti-theft systems a code signal is transmitted to a receiver in the motor vehicle with the aid of a key. In the receiver the code signal is compared with a desired code and if they correspond a release signal for a security unit is generated. With such systems doors can be opened or departure blocks can be released.

However, with carnapping (hijacking of the motor vehicle) such systems fail, since the motor vehicle has already been released or opened by the authorized user prior to the instant of the carnapping.

is A known speech recognition device (EP 0 100 773 B or DE 32 38 853 A1) serves to activate actuators in a motor vehicle in dependence upon spoken commands. If the command,open doors" is expressed, then the doors open. Unauthorized users can repeat at any time this command which is always known and can therefore climb into the motor vehicle.

The invention seeks to provide an improved, but easily operated antitheft system.

According to the present invention, there is provided an anti-theft system for a motor vehicle, having a receiving unit, incorporating a speech recognition unit, for installation in the motor vehicle, wherein the receiving unit and speech recognition unit are designed to receive spoken passwords, analyze them, and compare them with predetermined desired values and, upon correspondence, to emit a control signal to a security unit.

The user has to say a password which must correspond with a predetermined desired passwcrd. Then a security unit, such as an immobiliser, is actuated. The solution has the advantage that by way of speech input each vehicle owner has his own "code,,, namely the characteristic tone of his speech in addition to the meaning of his spoken password. In this way the code diversity and thus the security against unauthorized 5 use is considerably increased.

Advantageous developments of the invention are set out in the subclaims. Thus, the anti-theft system can activate an immobiliser, open doors or emit an alarm. This can also take place in a time-delayed manner, so that the thief does not notice the protection system at first.

For a better understanding of the present invention, and to show how it may be brought into effect, reference will now be made, by way of example, to the accompanying drawings, in which:

Figure 1 shows an anti-theft system of a motor vehicle in accordance with the invention which an authorized user operates by way of speech input.

Figure 2 shows a block diagram of the anti-theft system.

An anti-theft system for a motor vehicle has a stationary receiving unit 2 arranged on or in the motor vehicle 1, as shown in Figure 1. The receiving unit 2 has a speech recognition module 9 which receives a spoken password with the aid of a microphone 3.

The password is an acoustic, auditive speech signal of a user 4 of the motor vehicle 1. The password is determined by the owner or the authorized user 4 of the motor vehicle. During an initialization phase the password is recorded in an analog or a digital manner and is permanently stored in the receiving unit 2.

Acoustic sounds, individual words or whole sentences can serve as the password. Thus, for example, the sentence 'My beautiful car" can be used as the password.

The password is evaluated in the speech recognition module 9 of the receiving unit 2, shown in Figure 1, and is compared with the desired password recorded in the initialization phase. If the passwords correspond, a control signal is emitted to a security unit 5, whereby the security unit 5 is activated or deactivated.

Such security units 5 can be door locks, alarm devices or an immobiliser. When the door locks are activated the doors are unlocked and the motor vehicle 1 can be opened. The activated alarm device emits an alarm. The activated immobiliser controls the motor control, the ignition coil, the fuel pump or similar devices in such a way that the motor vehicle 1 can no longer be driven.

The passwords may be analyzed in a user-dependent manner, i.e. according to their phonetic characteristics, such as tone, pitch, speech rhythm etc. or in a user-independent manner, i.e. according to the word sense or the meaning of the spoken words.

If the passwords are evaluated in a user-dependent manner it is sufficient - conditional upon small deviations in the speech, for example as a consequence of the user 4 having a cold - if the passwords correspond with the recorded desired passwords only within a tolerance width. However, speech patterns characteristic to the user 4 can also be stored in the receiving unit 2, with which patterns the spoken password is compared. Through analysis or synthesis of the spoken password and a comparison with the stored patterns, the speech recognition unit determines whether there is extensive correspondence. A control signal, i.e. an authorization to open and start the motor vehicle 1, can be generated if the spoken password corresponds to the stored password.

Speech recognition modules with speech analysis and speech synthesis are adequately known. With them, both the sense of the spoken words and their phonetic characteristics are registered. Their mode of functioning does not need to be explained in more 5 detail here.

As soon as the password is spoken the anti-theft system is activated if it was previously deactivated and it is deactivated if it was previously activated. Advantageously separate passwords are used to activate and deactivate the anti-theft system.

With a delay device 6, such as a timer, which is arranged either in the receiving unit 2 (as shown) or in the security unit 5 to be controlled, the generation of the control signal or the activation of the protection system can be delayed for a predetermined duration.

The anti-theft system will be explained in more detail with reference to a concrete example. An authorized user 4 of a motor vehicle 1 has got into his vehicle in the normal way, has deactivated the immobiliser and has started the engine. During the drive or during a short stop he is attacked by a thief and compelled to leave his motor vehicle 1. If he now says his password, for example "My beautiful car", the protection system, in particular the immobiliser, is activated. Advantageously the immobiliser is activated only later, after a predetermined time delay, so that the user 4 can get to a safe place and the thief does not notice the activated protection system at first.

After the predetermined time delay the motor vehicle 1 stops and can no longer be moved.

Even if the thief repeats the password the immobiliser is not deactivated because his phonetic characteristics do not correspond with those of the authorized user 4. Furthermore, the thief cannot Lnitialize the motor vehicle 1, because he does not -S- have the necessary authorization, such as vehicle letter or an authorized key.

For safety reasons the engine must not shut off immediately the immobiliser is operated before the motor vehicle 1 comes to a standstill. Therefore, first of all the vehicle speed must be reduced to zero by the motor control or by braking. After that, the engine is shut off and the immobiliser is activated so that the motor vehicle 1 can no longer be started.

Through the activation of the protection system an alarm device 7 (Figure 2) can also be activated, by way of which optical or acoustic signals are generated by way of headlights, indicator lights or the horn. In this way third parties become aware the stolen motor vehicle 1 has been stolen.

The alarm device 7 can likewise be a mobile telephone which deposits a call, not noticed by the thief, at a receiving station 11, for example a police station. If at the same time the position of the motor vehicle 1 or vehicle-specific data, such as registration number or police means of identification, are communicated, the stolen motor vehicle 1 can be found more quickly.

In place of a mobile telephone a HF-transmitter can also be used as alarm device 7 in the motor vehicle 1, which transmits an alarm call by way of a satellite to a receiving station 11 of a security department as soon as the protection system is activated.

In addition to the receiving unit 2 for acoustic speech signals a portable transmitter 8 in the form of a key or a chip card or a switch 10 hidden on the motor vehicle 1 together with the receiving unit 2 for wirelessly transmitted signals can also be used. Through the actuation of the transmitter 8 or through approach to the receiving unit 2 a code signal is sent to the receiving unit 2. The code signal can be transmitted inductively, capacitively, at high frequency, at low frequency or optically. In the receiving unit 2 it is compared with a stored desired signal. Upon correspondence a control signal is generated which activates or deactivates a security unit.

The anti-theft system in accordance with the invention can be used not only with motor vehicles, but also with other objects such as buildings or safes. In this respect it is essential that the speech is used as coded means of access to the object or as protection against theft.

Claims

1. Anti-theft system for a motor vehicle, having a receiving unit, incorporating a speech recognition unit, for installation in the motor vehicle, wherein the receiving unit and speech recognition unit are designed to receive spoken passwords, analyze them, and compare them with predetermined desired values and, upon correspondence, to emit a control signal to a security unit.

2. Anti-theft system according to claim 1, wherein the security unit is an immobiliser.

3. Anti-theft system according to claim 1 or 2, wherein the receiving unit has a delay device which only emits the control signal after a predetermined duration.

4. Anti-theft system according to claim 1 or 2, wherein the security unit has a delay device which activates or deactivates the security unit after a predetermined duration after receiving the control signal.

s. Anti-theft system according to one of claims 1-4, wherein the security unit is a door lock of the motor vehicle.

6. Anti-theft system according to one of claims 1-5, wherein the security unit is an alarm device.

7. Anti-theft system according to claim 6, wherein the alarm device emits optical or acoustic signals.

8. Anti-theft system according to claim 6 or 7, wherein the alarm device transmits a signal wirelessly to a receiving station.

9. Anti-theft system according to claim 8, wherein the alarm device is a mobile telephone which transmits a signal to a receiving station. 35

10. Anti-theft system according to claim 8, wherein the alarm device is a HF-transmitter which transmits a HF-signal to a satellite.

11. Anti-theft system according to any preceding claim, also having a portable transmitter which, upon actuation or upon approach to the receiving unit, transmits a code signal to the receiving unit, whereby, upon correspondence with a stored code signal, the control signal is transmitted to the security unit.

12. Anti-theft system according to any preceding claim, also having a switch arranged hidden on the motor vehicle and by means of which, upon actuation, a code signal is transmitted to the receiving unit, whereby, upon correspondence with a stored code signal, the control signal is transmitted to the security unit.

13. Anti-theft system according to any preceding claim, wherein the receiving unit analyzes the speech signals with the aid of a speech recognition unit according to pitch, tone or meaning of the spoken words and compares them with predetermined, stored data.

14. Anti-theft system according to claim 13, wherein the receiving unit judges that the speech signals match the stored data if the speech signals deviate from the stored data by less than a predetermined amount.

15. Anti-theft system substantially as herein described with reference to the accompanying drawings.

16. Motor vehicle having an anti-theft system as claimed in any preceding claim.

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