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

摘要

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.

主权项

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