Anti-lockout smart key system

• US 5,831,520 A
• Filed: 01/14/1998
• Issued: 11/03/1998
• Est. Priority Date: 01/14/1998
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Motor Company
• Inventors: Stephan, Craig Hammann
• Primary Examiner(s): Swarthout, Brent
• Assistant Examiner(s): Trieu, Van T.
• Application Number:
  US09/006,624
• Time in Patent Office: 293 Days
• Field of Search: 340/457, 340/457.1, 340/426, 340/539, 340/542, 340/541, 340/825.31, 340/568, 307/9.1, 307/10.1, 307/10.3, 307/10.4, 307/10.5
• US Class Current: 340/457
• CPC Class Codes: B60R 25/225 key in lock presence switch

Abstract

An apparatus and method for alerting a driver that the keys have been left inside the vehicle with the doors locked uses a smart key. The smart key (10) has a built-in transmitter and receiver (12), a battery (11) and a mechanical switch (14) for deactivating the transmitter/receiver to conserve key battery power. The apparatus and method cover the four different situations that can exist after the vehicle doors are closed and locked. First the driver is inside the vehicle. Second, the driver is outside the vehicle and has the key. Third, the driver has left the key behind in the ignition (16). Fourth, the driver has left the key behind somewhere in the vehicle other than the ignition. Situations three and four merit alerting the driver, and the system activates an alarm (24) to notify the driver and temporarily unlock the doors.

Claims

1. An anti-lockout system for a vehicle, said vehicle having doors and an ignition, said anti-lockout system comprising:

a smart key having a built-in transmitter/receiver, a battery and a mechanical switch, said switch opening when inserted into a lock to deactivate said transmitter/receiver;

means for generating door condition signals representing locked, unlocked, open and closed conditions of said doors;

means for generating ignition condition signals representing on, off, key inserted and key removed conditions of said ignition;

a vehicle transmitter/receiver for communicating with said transmitter/receiver in said key;

an alarm; and

a controller receiving the ignition condition signals and door condition signals, and receiving signals from the vehicle transmitter/receiver and key transmitter/receiver, said controller activating said alarm and temporarily unlocking said doors when key is left in the vehicle and the doors are closed and locked.

2. An anti-lockout system, as set forth in claim 1, wherein said vehicle transmitter/receiver is powered to receive for 1.3 seconds.

3. An anti-lockout system, as set forth in claim 1, wherein said key transmitter/receiver is powered to receive only a few milliseconds each second until deactivated by receiving a signal from the vehicle transmitter/receiver.

4. An anti-lockout system, as set forth in claim 1, wherein said key transmitter/receiver is powered to receive for five milliseconds each second until deactivated by receiving a signal from the vehicle transmitter/receiver.

5. An anti-lockout smart key system, as set forth in claim 1, wherein said key transmitter/receiver is repeatedly powered to receive for five milliseconds and standby for one second until deactivated by receiving a signal from the vehicle transmitter/receiver.

6. An anti-lockout system for a vehicle, comprising:

a smart key having a built-in transmitter/receiver and a mechanical switch, said switch opening when inserted into a lock to deactivate said transmitter/receiver;

a door locking system having a door with a door lock for receiving said smart key and having means for generating door condition signals representing locked, unlocked, open and closed conditions of said door;

an ignition locking system having an ignition lock for receiving said key and having means for generating ignition condition signals representing on, off, key inserted and key removed conditions of said ignition lock;

a vehicle transmitter/receiver for communicating with said transmitter/receiver in said key;

an alarm; and

a controller receiving signals from said ignition locking system, door locking system and vehicle transmitter/receiver, said controller activating said alarm and temporarily unlocking said door when key is left in the vehicle and the door is closed and locked.

7. An anti-lockout system, as set forth in claim 6, wherein said vehicle transmitter/receiver is powered to receive for 1.3 seconds.

8. An anti-lockout system, as set forth in claim 6, wherein said key transmitter/receiver is powered to receive only a few milliseconds each second until deactivated by receiving a signal from the vehicle transmitter/receiver.

9. An anti-lockout system, as set forth in claim 6, wherein said key transmitter/receiver is powered to receive for five milliseconds each second until deactivated by receiving a signal from the vehicle transmitter/receiver.

10. An anti-lockout smart key system, as set forth in claim 6, wherein said key transmitter/receiver is repeatedly powered to receive for five milliseconds and standby for one second until deactivated by receiving a signal from the vehicle transmitter/receiver.

11. A method for activating an alarm of a vehicle to alert a driver that a key has been left in the vehicle with doors locked, comprising the steps of:

determining whether a last door has been closed;

determining whether a last door has been locked;

transmitting a signal from a vehicle transmitter/receiver when the last door is closed and locked;

determining whether a smart key is inserted in an ignition lock, said smart key having a built-in transmitter/receiver, a battery and a mechanical switch, said switch closing when inserted into the ignition lock to deactivate said key transmitter/receiver;

activating an alarm when the key is in the ignition lock and all doors are locked;

transmitting a signal from the vehicle transmitter/receiver when all doors are locked and the key is not in the ignition lock;

receiving the signal from the vehicle transmitter/receiver through the key transmitter/receiver;

transmitting a signal from the key transmitter/receiver to the vehicle transmitter/receiver after receiving the signal from the vehicle transmitter/receiver;

receiving the signal transmitted from the key transmitter/receiver by the vehicle transmitter/receiver;

determining whether the signal received by the vehicle transmitter/receiver is greater than a predetermined threshold level;

activating the alarm when the signal received by the vehicle transmitter/receiver is above the threshold level.

12. A method, as set forth in claim 11, wherein the step of activating the alarm includes temporarily unlocking the door.

13. A method, as set forth in claim 11, wherein the step of receiving the signal from the vehicle transmitter/receiver through the key transmitter/receiver includes powering the key transmitter/receiver to receive for only a few milliseconds each second until deactivated by receiving the signal from the vehicle transmitter/receiver.

14. A method, as set forth in claim 11, wherein the step of receiving the signal from the vehicle transmitter/receiver through the key transmitter/receiver includes powering the key transmitter/receiver to receive for five milliseconds each second until deactivated by receiving the signal from the vehicle transmitter/receiver.

15. A method, as set forth in claim 11, wherein the step of receiving the signal from the vehicle transmitter/receiver through the key transmitter/receiver includes repeatedly powering the key transmitter/receiver to receive for five milliseconds and standby for one second until deactivated by receiving the signal from the vehicle transmitter/receiver.

16. A method, as set forth in claim 11, wherein the step of transmitting the signal from the vehicle transmitter/receiver includes generating sound waves and forming acoustical standing wwaves inside the vehicle.

17. A method, as set forth in claim 11, including the step of locating a vehicle antenna inside the vehicle where transmission between the vehicle transmitter/receiver and the key transmitter/receiver is attenuated by sheet metal of the vehicle when the key is outside the vehicle.

18. A method, as set forth in claim 11, including the step of locating a vehicle antenna outside the vehicle where transmission between the vehicle transmitter/receiver and the key transmitter/receiver is attenuated by sheet metal of the vehicle when the key is inside the vehicle.

19. A method, as set forth in claim 11, including the step of receiving an attenuated signal and concluding that the key is inside the vehicle.

20. A method, as set forth in claim 11, including the step of receiving a nonattenuated signal and concluding that the key is outside the vehicle.