Method for processing a presence signal in a hands-free vehicle access system having capacitive sensors

• US 9,406,179 B2
• Filed: 06/19/2014
• Issued: 08/02/2016
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive France (Continental AG), Continental Automotive GmbH (Continental AG)
• Inventors: Belleza, Thierry, Verdon, Isabelle, Ayeva, Bachir
• Primary Examiner(s): Miller, Brian
• Application Number:
  US14/308,883
• Publication Number:
  US 20150002263A1
• Time in Patent Office: 775 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 2209/61 Signal comprising different frequencies, e.g. frequency hopping
• CPC Class Codes: G07C 2209/65 using means for sensing the user's hand
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks
• CPC Class Codes: G07C 9/28 the pass enabling tracking or indicating presence

Abstract

Method for processing a presence signal in a hands-free vehicle access system having capacitive sensors. After starting steps constituted by nominal operation, switching to low-energy consumption mode, and switching to polling of an interrogation signal at nominal frequency, this method includes: presence testing with nominal polling; requesting the identity of the electronic key, transmitted via a central unit; detecting the presence of a hand on a handle transmitted via a capacitive sensor to the central unit; and authorizing the unlocking of the vehicle. The method includes a step of reducing the frequency of signals transmitted by the antenna of the central unit so as to switch into a “slow polling” test, such that the capacitive sensors have sufficient time intervals to test the central unit for the presence of a hand during the information step. The capacitive sensors then have greater availability to signal the presence of a hand.

Claims

1. A method for processing a presence signal in a hands-free vehicle access system having a capacitive sensor and an antenna fitted in a door handle of said vehicle and connected to a central unit, comprising:

a step of testing for the presence of an electronic key (26) via an emission of an interrogation signal at a regular nominal frequency, this emission being referred to as nominal “

polling”

, transmitted via the antenna connected to the central unit installed in the vehicle,

a step of testing for an identity request (30) destined for the electronic key and transmitted via said antenna of the central unit, and, if the test for an identity request is successful;

two steps of testing for the presence of a hand (34, 36);

a presence detection test (34) by the capacitive sensor, and

a validation test (36) by the central unit to validate whether the capacitive sensor is in the same door handle as said antenna, and

a final step of authorizing the unlocking (38) of the vehicle,

wherein, if the test for an identity request is not successful, the method returns to the step of testing for the presence of the electronic key, and

wherein, before the two steps of testing for the presence of a hand (34, 36), said method comprises a step of decreasing the frequency of said interrogation signal transmitted via the antenna of the central unit so as to pass into slow-frequency “

polling”

mode (32), in which the frequency is ten-times lower than the regular nominal frequency.

2. The processing method according to claim 1, wherein an initial start step (20) is followed by a switching of the central unit to a low-energy consumption mode (22).

3. The processing method according to claim 1, wherein the central unit is switched to a high-energy consumption mode (28) after effective identification of an electronic key during the step of testing for an identity request (30).

4. The processing method according to claim 1, wherein the central unit is switched to a high-energy consumption mode (28) when the response to the step of testing for the presence of a key (26) is positive.

5. The processing method according to claim 1, wherein if there is no validation of detection of a hand by the capacitive sensor during the presence detection step (34) for a predetermined period, the method returns to the step of testing for the presence of the electronic key (26).

6. The processing method according to claim 1, wherein the return to the step of testing for the presence of the electronic key (26) prompts a return to a polling of an interrogation signal at the nominal frequency (24).

7. The processing method according to claim 1, wherein the vehicle constitutes a signal processing zone for the antenna and for the capacitive sensor of the hands-free vehicle access system.

8. The processing method according to claim 7, wherein the global zone is broken down into a number of signal processing zones for the antenna and for the capacitive sensor of the hands-free vehicle access system.

9. The processing method according to claim 7, wherein if the electronic key is no longer detected in the signal processing zone once a predetermined period of time has elapsed, the method returns to the step of testing for the presence of the electronic key (26).

10. The processing method according to claim 7, wherein the signal processing zones are formed of two side door zones and one vehicle luggage compartment zone;

if the electronic key is detected from the luggage compartment zone, the central unit returns to the step of testing for the presence of the electronic key (26).

11. The processing method according to claim 8, wherein if the electronic key is no longer detected in the signal processing zone once a predetermined period of time has elapsed, the method returns to the step of testing for the presence of the electronic key (26).

12. The processing method according to claim 8, wherein the signal processing zones are formed of two side door zones and one vehicle luggage compartment zone;

if the electronic key is detected from the luggage compartment zone, the central unit returns to the step of testing for the presence of the electronic key (26).

13. The processing method according to claim 9, wherein the signal processing zones are formed of two side door zones and one vehicle luggage compartment zone;

if the electronic key is detected from the luggage compartment zone, the central unit returns to the step of testing for the presence of the electronic key (26).

14. The processing method according to claim 2, wherein the central unit is switched to a high-energy consumption mode (28) after effective identification of an electronic key during the step of testing for an identity request (30).

15. The processing method according to claim 2, wherein the central unit is switched to a high-energy consumption mode (28) when the response to the step of testing for the presence of a key (26) is positive.

16. The processing method according to claim 2, wherein, if there is no validation of detection of a hand by the capacitive sensor during the presence detection step (34) for a predetermined period, the method returns to the step of testing for the presence of the electronic key (26).