| 摘要 |
A passive remote keyless entry system (20) includes a plurality of sensors (30 a-e) each associated with a door (34 a-e) of the vehicle (32). Each sensor (30 a-e) detects the presence and distance of a key fob (22) from the sensor. By monitoring the distance of the key fob (22) from the sensor (30 a-e), the sensor (30 a-e) determines if the key fob (22) is approaching or moving away from the associated door (34 a-e). If the sensor (30 a-e) determines that the key fob (22) is approaching, an interrogation signal is sent from the security system to the key fob (22). If the proper code is returned by the key fob, the associated door (34 a-e) is unlocked. If the sensor determines that the key fob (22) is moving away from the associated door (34 a-e), the doors (34 a-e) are locked. The sensors (30 a-e) can also determine whether the key fob (22) is simply passing by, in which case the driver probably does not wish to enter the vehicle.
|
