METHOD FOR PROCESSING A PRESENCE SIGNAL IN A HANDS-FREE VEHICLE ACCESS SYSTEM HAVING CAPACITIVE SENSORS

• US 20150002263A1
• Filed: 06/19/2014
• Published: 01/01/2015
• 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: AYEVA, Bachir, BELLEZA, Thierry, VERDON, Isabelle
• Granted Patent: US 9,406,179 B2
• Time in Patent Office: Days
• US Class Current: 340/5.61
• 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. Method for processing a presence signal in a hands-free vehicle access system having capacitive sensors fitted in a door handle of said vehicle, comprising:

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

polling”

, transmitted via an antenna connected to a 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 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,

characterized in that, in addition, 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 lower than the regular nominal frequency.

2. Processing method according to claim 1, characterized in that an initial step of nominal starting, called Start (20), is followed by a switching of the central unit to a low-energy consumption mode (22).

3. Processing method according to claim 1, characterized in that 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. Processing method according to claim 1, characterized in that 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. Processing method according to claim 1, characterized in that, if no capacitive sensor sends information during a presence detection step (34) of the presence test (34, 36) once a predetermined period of time has elapsed, the method returns to the step Start (20).

6. Processing method according to claim 1, characterized in that the return to the step Start (20) prompts a return to a polling of an interrogation signal at nominal frequency (24).

7. Processing method according to claim 1, characterized in that the vehicle constitutes a sole global signal processing zone for the antennas and capacitive sensors of the hands-free access system.

8. Processing method according to claim 7, characterized in that the global zone is broken down into a number of signal processing zones for the antennas and sensors of the hands-free access system.

9. Processing method according to claim 7, characterized in that if the electronic key is no longer detected in the processing zones once a predetermined period of time has elapsed, the method returns to the step Start (20).

10. Processing method according to claim 7, characterized in that 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 nominal polling.

11. Processing method according to claim 8, characterized in that if the electronic key is no longer detected in the processing zones once a predetermined period of time has elapsed, the method returns to the step Start (20).

12. Processing method according to claim 8, characterized in that 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 nominal polling.

13. Processing method according to claim 9, characterized in that 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 nominal polling.

14. Processing method according to claim 2, characterized in that 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. Processing method according to claim 2, characterized in that 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. Processing method according to claim 2, characterized in that, if no capacitive sensor sends information during a presence detection step (34) of the presence test (34, 36) once a predetermined period of time has elapsed, the method returns to the step Start (20).