Secure system for the control of the unlocking of at least one openable panel of a motor vehicle

• US 7,227,448 B2
• Filed: 06/20/2001
• Issued: 06/05/2007
• Est. Priority Date: 11/04/1999
• Status: Expired due to Fees

• Current Assignee: Valeo Electronique
• Original Assignee: Valeo Electronique
• Inventors: Smith, Colin, Menard, Eric
• Primary Examiner(s): Horabik; Michael
• Application Number:
  US09/883,963
• Publication Number:
  US 20020163420A1
• Time in Patent Office: 2,176 Days
• Field of Search: 340/5.72, 340/825.69, 340/72, 364/724, 375/1
• US Class Current: 340/5.72
• CPC Class Codes: G07C 2009/00476 dynamically
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

A system for controlling locking/unlocking of at least one openable panel of a vehicle is provided. The system is especially designed to prevent unauthorized persons from intercepting and copying signals transmitted between the vehicle and a transmission/reception device held by the user.

Claims

1. A system for controlling locking/unlocking means of at least one openable panel of a vehicle, comprising:

vehicle transmission/reception means (3, 4, 5) carried by the vehicle, comprising

vehicle memory means (7) comprising a vehicle circular shift register in which is stored a pseudo-random code;

vehicle transmission means (3, 6, 7) for transmitting an interrogation signal which carries the pseudo-random code; and

vehicle de-spreading means (6, 7, 8) for de-spreading a response signal received unless a pseudo-random code carried by the response signal is not synchronized in substantial correlation with a corresponding pseudo-random code stored in the vehicle memory means (7) by a time shift less than required for an intermediate transmission means to intercept and retransmit a response signal, and for verifying whether the received signal carries a signature of a user transmission means; and

user transmission/reception means (9, 10, 11) intended to be carried by a user for transmitting the response signal for controlling unlocking actuation of the operable panel, comprising

user memory means comprising a user circular shift register (13) in which is stored the pseudo-random code;

user de-spreading means (12, 13, 14) for de-spreading the transmission signal received unless the pseudo-random code carried by the interrogation signal is not synchronized in substantial correlation with a corresponding pseudo-random code stored in the user memory means (13) by a time shift less than required for an intermediate transmission means to intercept and retransmit the interrogation signal; and

the user transmission means (9, 12, 13, 14) for transmitting the response signal which carries the pseudo-random code and the signature which is specific to the user transmission/reception means.

2. A system according to claim 1, wherein:

the interrogation signal transmitted by the vehicle transmission/reception means comprises a key code; and

the response signal transmitted by the user transmission/reception means comprises a secret code determined by the user transmission/reception means as a function of the key code.

3. A system according to claim 2, wherein the vehicle transmission/reception means further comprise a mixing means for mixing the key code with the pseudo-random code carried by the interrogation signal.

4. A system according to claim 2, wherein the user transmission/reception means further comprise mixing means for mixing the secret code with the pseudo-random code carried by the response signal.

5. A system according to claim 2, wherein at least one of the key code and the secret code comprise the pseudo-random code of the interrogation signal or the response signal.

6. A system according to claim 1, wherein the signature consists of the pseudo-random code of the response signal.

7. A system according to claim 1, wherein the system comprises means for synchronizing the vehicle memory means and the user memory means prior to transmission of the interrogation signal.

8. A system according to claim 7, wherein:

the pseudo-random code comprises a post-synchronization pseudo-random code;

the user transmission/reception means transmits a pre-synchronization pseudo-random code upon activation of the user transmission/reception means; and

the vehicle transmission/reception means comprise means for self-synchronizing with the pre-synchronization pseudo-random code transmitted by the user transmission/reception means.

9. A system according to claim 8, wherein the pre-synchronization pseudo-random code is shorter than the post-synchronization pseudo-random code.

10. A system according to claim 9, wherein the post-synchronization pseudo-random code comprises 127-bit codes.

11. A system according to claim 1, wherein the interrogation signals and response signals comprise RF signals modulated by a two-phase NRZ modulation.

12. A system according to claim 1, wherein the vehicle is an automobile.

13. A system according to claim 1, wherein the time shift comprises less than one half of a bit period with respect to the code of the user circular shift register.

14. The system according to claim 1, wherein when said response signal is received after a delay exceeding said time shift, said system prevents unlocking actuation of said operable panel.

15. The system according to claim 13, wherein when said response signal is received after a delay exceeding said half bit period, said system prevents unlocking actuation of said operable panel.