Method for secure access to a motor vehicle
A method for securely accessing a motor vehicle whose opening elements are locked and unlocked through wireless communication between a portable access device and an access control module on board the vehicle. The method includes authenticating the device with the access control module, unlocking the vehicle when the device has been authenticated, periodically transmitting, by way of the access control module, an interrogation signal into at least part of the passenger compartment of the vehicle intended for the device following unlocking of the vehicle, upon each reception by the device of said interrogation signal, triggering a first timeout the duration of which is greater than the transmission period of the interrogation signal, and deactivating the device when the first timeout has expired and the immobile state of the device is detected.
1. A method for securely accessing a motor vehicle whose opening elements are locked and unlocked through wireless communication between a portable access device and an access control module on board said motor vehicle, said portable access device comprising a motion sensor, the method comprising:
authenticating the portable access device with the access control module,
unlocking the motor vehicle when the portable access device has been authenticated,
periodically transmitting, by way of the access control module, an interrogation signal into at least part of the passenger compartment of the motor vehicle intended for the portable access device following unlocking of the motor vehicle,
upon each reception by the portable access device of said interrogation signal, triggering a first timeout a duration of which is greater than a transmission period of the interrogation signal,
deactivating the portable access device when the first timeout has expired and an immobile state of said portable access device is detected by the motion sensor, wherein the immobile state of the portable access device is detected when the motion sensor does not detect any motion for a duration of a second timeout.
2. The method as claimed in claim 1 , wherein the second timeout is triggered upon each motion of the portable access device detected by the motion sensor, the duration of the second timeout then being greater than the duration of the first timeout.
3. The method as claimed in claim 1 , wherein the second timeout is triggered only when the first timeout has expired.
4. The method as claimed in claim 1 , wherein the duration of the period of the interrogation signal is between 1 and 5 minutes.
5. The method as claimed in claim 1 , wherein the duration of the first timeout is between 3 and 15 minutes.
6. A portable device for accessing a motor vehicle whose opening elements are locked and unlocked through wireless communication between said portable device and an access control module on board said motor vehicle, said portable device comprising a motion sensor and being able to authenticate itself with the access control module, the portable device being configured so as to:
receive an interrogation signal transmitted periodically by the access control module into at least part of the passenger compartment of the motor vehicle intended for the portable device following unlocking of the motor vehicle,
upon each reception by the portable device of said interrogation signal, trigger a first timeout a duration of which is greater than a transmission period of the interrogation signal,
deactivate the portable device when the first timeout has expired and an immobile state of said portable device is detected on the basis of the motion sensor, the portable device being configured so as to detect the immobile state when the motion sensor does not detect any motion for a duration of a second timeout.
7. The portable device as claimed in claim 6 , wherein the duration of the first timeout is greater than or equal to three times the period of the interrogation signal.
8. A system for the secure unlocking and locking of a motor vehicle, said system comprising:
at least one portable device as claimed in claim 6 , and
a motor vehicle whose opening elements are able to be locked and unlocked through wireless communication between said portable device and an access control module on board said motor vehicle, said access control module being configured to authenticate the portable device, to unlock the vehicle when the portable device has been authenticated, and to periodically transmit an interrogation signal into at least part of the passenger compartment of the motor vehicle intended for the portable device following unlocking of the motor vehicle.
9. A system for the secure unlocking and locking of a motor vehicle, said system comprising:
at least one portable device as claimed in claim 7 , and
a motor vehicle whose opening elements are able to be locked and unlocked through wireless communication between said portable device and an access control module on board said motor vehicle, said access control module being configured:
to authenticate the portable device,
unlock the motor vehicle when the portable device has been authenticated, and
to periodically transmit an interrogation signal into at least part of the passenger compartment of the motor vehicle intended for the portable device following unlocking of the motor vehicle.