Method for activating a vehicle function from a portable access device and associated activation module

1. An activation module, intended to be fitted to a motor vehicle for the purpose of activating a function of the vehicle from a portable access device carried by a user, the activation module comprising:

a single coil;

a first controller for a device for detecting pressure from a hand of the user;

a second controller for a near-field communication device having a communication frequency that is capable of communicating with the portable access device;

a selector, connected to the single coil, having two positions:

a first position in which the selector connects said single coil to the first controller and disconnects the single coil from the second controller in order to constitute the pressure detection device;

a second position in which the selector connects said single coil to the second controller and disconnects the single coil from the first controller in order to constitute the near-field communication device;

a target having a void, said target being located facing the single coil and capable of moving with respect to the single coil;

an impedance adjuster that is connected to the target;

a third controller for the selector.

2. The activation module as claimed in claim 1 , wherein the adjuster is suitable for:

adjusting an impedance to below a minimum threshold when the selector is in the first position; and

adjusting the impedance to above a maximum threshold when the selector is in the second position.

3. The activation module as claimed in claim 2 , wherein the first controller comprises means for oscillating the single coil at a resonant frequency, means for measuring an actual frequency of oscillation of said single coil and means for comparing said actual frequency with a first predetermined threshold.

4. The activation module as claimed in claim 1 , wherein the first controller comprises means for oscillating the single coil at a resonant frequency, means for measuring an actual frequency of oscillation of said single coil and means for comparing said actual frequency with a first predetermined threshold.

5. The activation module as claimed in claim 1 , wherein the second controller comprises impedance-adjusting means, means for measuring the voltage across the terminals of the single coil, means for comparing said voltage with a second threshold value and means for transmitting/receiving data by near-field communication.

6. The activation module as claimed in claim 1 , wherein the target takes the shape of an open ring, and the single coil is rectangular in shape.

7. The activation module as claimed in claim 1 , wherein the target is made of an amagnetic and conductive material, and the dimensions of the void are at least substantially equal to the dimensions of the single coil.

8. A method for activating a function of a vehicle from a portable access device carried by user, said vehicle comprising at least one activation module as claimed in claim 1 , comprising:

placing the selector in the first position in order to detect the pressure from the hand of the user; and

placing the selector in the second position in order to authenticate the portable access device by near-field communication,

valid identification of the portable access device and detection of the pressure from the hand triggering the activation of the function of the vehicle.

9. The activation method as claimed in claim 8 , wherein, when the selector is in the second position, the near-field communication is preceded by a phase of detecting an approach of the portable access device.

10. The activation method as claimed in claim 9 , wherein, when the selector is in the first position, the detection of pressure from the hand is determined by an increase in the resonant frequency of the single coil.

11. The activation method as claimed in claim 8 , wherein, when the selector is in the first position, the detection of pressure from the hand is determined by an increase in the resonant frequency of the single coil.

12. A deployable door handle comprising two parts, a first, movable part capable of being deployed and a second, fixed part comprised within the door, and comprising an activation module as claimed in claim 1 .

13. A door handle, comprising an activation module as claimed in claim 1 .