Passive remote keyless entry system

• US 6,236,333 B1
• Filed: 06/17/1998
• Issued: 05/22/2001
• Est. Priority Date: 06/17/1998
• Status: Expired due to Term

• Current Assignee: Lear Corporation EEDS and Interiors Incorporated (Lear Corporation)
• Original Assignee: Lear Automotive Dearborn, Incorporated (Lear Corporation)
• Inventors: King, Joseph David
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): BANGACHON, WILLIAM L
• Application Number:
  US09/098,612
• Time in Patent Office: 1,070 Days
• Field of Search: 340/825.31, 340/572.6, 340/551, 340/10.1, 340/10.3, 340/10.33, 340/10.34, 340/10.4
• US Class Current: 340/5.61
• CPC Class Codes: B60R 25/2036 by using the door logic and door and engine unlock means
• CPC Class Codes: B60R 25/24 using electronic identifiers containing a code not memorised by the user
• CPC Class Codes: G07C 2009/00373 whereby the wake-up circuit is situated in the lock
• CPC Class Codes: G07C 2009/00396 starting with prompting the keyless data carrier
• CPC Class Codes: G07C 2009/00523 opening of different locks separately
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 2009/00984 fob
• CPC Class Codes: G07C 2209/08 With time considerations, e.g. temporary activation, valid time window or time limitations
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

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

Claims

1. A passive keyless entry system that monitors a presence and a direction of movement of a portable keyless entry device relative to a sensor located on a vehicle for unlocking and locking a vehicle door based on the direction of movement of the portable keyless entry device relative to the sensor, the system comprising:

a sensor located on the vehicle that detects a presence of the keyless entry device within a predetermined range to the sensor and generates a signal indicative of distance between the keyless entry device and the sensor based on the sensor measuring an intensity of the presence of the keyless entry device over time; and

a controller arranged to determine the direction of movement relative to the sensor based on the sensor signal, wherein the controller is further arranged to control operation of a vehicle door actuator as follows;

unlocking the door when the direction of movement is determined to be approaching the sensor and locking the door when the direction of movement is determined to be moving away from the sensor.

2. The system of claim 1, wherein said sensor determines if said movement is within a first threshold distance from said sensor, said system further including a transmitter sending an interrogation signal based upon said sensor detecting said movement within said first threshold distance.

3. The system of claim 2, further including a receiver receiving a code after said interrogation signal is transmitted.

4. The system of claim 2, wherein said system includes a sleep mode, said system exiting said sleep mode based upon said sensor detecting said movement generally within a second threshold less than said first threshold.

5. The system of claim 1, wherein the portable keyless entry device comprises a portable fob, said sensor detecting said movement of said fob.

6. The system of claim 5, wherein said fob includes a magnet, said sensor detecting a magnetic field from said magnet.

7. The system of claim 6, wherein said sensor determines a magnitude of said magnetic field, a controller monitoring a profile of said magnitude of said magnetic field over time, said controller activating and deactivating said actuator based upon said profile.

8. The system of claim 1, wherein operation of a vehicle door actuator includes maintaining a locked or unlocked status of the door when the direction of movement is determined to be passing by the sensor.

9. A passive keyless entry system that monitors a presence and a direction of movement of a portable keyless entry device relative to a sensor located on a vehicle for unlocking and locking a vehicle door based on the direction of movement of the portable keyless entry device relative to the sensor, the system comprising:

a plurality of actuators for unlocking and locking the vehicle door;

a plurality of sensors, each associated with one of the plurality of actuators, wherein each sensor is arranged to detect a presence of the keyless entry device within a predetermined range to the sensor and generate a signal indicative of distance between the keyless entry device and the sensor based on the sensor measuring an intensity of the presence of the keyless entry device over time; and

a controller responsive to a generated sensor signal for deactivating an actuator based upon detection of motion of the keyless entry device toward the associated sensor.

10. The system of claim 9, wherein all of said actuators are activated upon detection of motion away from said sensors.

11. The system of claim 9, further including a controller receiving motion information from said sensors and selectively activating and deactivating each of said actuators, said controller deactivating only said actuator associated with said associated sensor that detected said motion toward said associated sensor while the others of said actuators are not deactivated.

12. The system of claim 9, further including a fob having a magnet, said sensors detecting a magnetic field from said magnet, said sensors detecting motion of said fob based upon said magnetic field, said actuators activated and deactivated based upon said motion of said fob.

13. The system of claim 12, further including a controller monitoring a profile of said magnetic field over time, said controller activating and deactivating said actuator based upon said profile.

14. The system of claim 13, further including a transmitter sending an interrogation signal based upon said sensors detecting said fob within a first predetermined threshold distance.

15. The system of claim 14, wherein said system includes a sleep mode, said system exiting said sleep mode based upon said sensors detecting motion generally within a second threshold less than said first threshold.

16. A method for passive keyless entry that controls operation of a vehicle locking system based on presence and direction of movement of a portable keyless entry device relative to a sensor located on a vehicle, the method comprising:

generating a signal indicative of a presence of the keyless entry device within a predetermined range to the sensor and distance between the keyless entry device and the sensor based on the sensor measuring an intensity of the presence of the keyless entry device over time;

determining the direction of movement relative to the sensor based on the generated distance signal;

automatically actuating the locking system to unlock a door when the direction of movement is determined to be approaching the sensor; and

automatically actuating the locking system to lock a door when the direction of movement is determined to be moving away from the sensor.

17. The method of claim 16 further including the step of:

sending an interrogation signal when the distance of the portable keyless entry device is below a first threshold.

18. The method of claim 16 further including the step of determining the direction of motion of said portable keyless entry device relative to each of a plurality of doors, said method further including the step of unlocking a first door based upon motion of said fob toward said first door while said plurality of doors other than said first door remain locked.

19. The method of claim 16 further including the steps of:

monitoring a profile of a magnetic field produced by the portable keyless entry device over time; and

controlling access to said area based upon said profile.

20. The method of claim 16, further comprises maintaining a locked or unlocked status of the door when the direction of movement is determined to be passing by the sensor.