Method And System To Prevent Vehicle Driveaway During Battery Charging

• US 20100320018A1
• Filed: 06/18/2009
• Published: 12/23/2010
• Est. Priority Date: 06/18/2009
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lathrop, James A., Mils, Jerry, Gwozdek, Thomas M., Lovett, Karin
• Granted Patent: US 8,393,423 B2
• Time in Patent Office: Days
• US Class Current: 180/65.27
• CPC Class Codes: B60T 17/18 Safety devices; Monitoring
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/182 including control of parking brakes
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2540/06 Ignition switch
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 30/18054 at stand still, e.g. engine in idling state hill holding B60W30/18118
• CPC Class Codes: F16H 61/22 Locking of the control input devices constructional features of locking or disabling mechanisms F16H63/34
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A system and method are disclosed for preventing driveaway or roll away of a plug-in electric vehicle when it is being charged or is coupled to an external power supply cord. When it is detected based on at least one of the following conditions: a current is flowing to the battery charger, a voltage source is coupled to the battery charger, an access door allowing access to the receptacle on board the vehicle is open and/or a plug detect switch indicates that a plug is coupled with the receptacle, a mechanical restraint on the driveline is prevented from being released. The mechanical restraint may be a parking brake. Alternatively, the mechanical restraint may include preventing the gear shift selector from being moved out of the park position.

Claims

1. A method to prevent vehicle movement when a battery onboard the vehicle is being charged, the vehicle having a mechanical vehicle-motion restraint and a battery charger coupled to a receptacle and the battery, the method comprising:

detecting a vehicle condition indicating that an external power supply cord is plugged into the receptacle; and

preventing the mechanical restraint from being released when such condition is detected.

2. The method of claim 1 wherein the mechanical restraint is applied to a driveline of the vehicle.

3. The method of claim 1, further comprising:

applying the mechanical restraint to the driveline of the vehicle when such condition is detected and the mechanical restraint is unapplied.

4. The method of claim 1 wherein:

the mechanical restraint comprises a pawl engaged with a parking gear wheel;

the parking gear wheel is coupled to a driveline of the vehicle; and

the preventing step comprises preventing disengagement of the pawl from the parking gear wheel.

5. The method of claim 4 wherein:

the pawl is coupled to a gear shift selector;

the gear shift selector has a park position in which the pawl is engaged with the parking gear wheel; and

the preventing disengagement of the pawl comprises preventing the gear shift selector from moving out of the park position.

6. The method of claim 1 wherein the mechanical restraint comprises a parking brake restraining at least one wheel of the vehicle from rotating and the preventing step comprises preventing release of the parking brake.

7. The method of claim 6 wherein the parking brake comprises one of:

an electric parking brake, an operator-actuated mechanical parking brake, and an anti-lock brake system.

8. The method of claim 1 wherein:

the mechanical restraint comprises an operator-actuated mechanical parking brake restraining at least one wheel of the vehicle from rotating;

the vehicle further comprises a parking brake solenoid coupled to the parking brake;

the solenoid has a lock position that prevents release of the parking brake; and

the preventing step comprises maintaining the parking brake solenoid in the lock position thereby preventing release of the parking brake.

9. The method of claim 1 wherein:

the vehicle has an access door on the exterior of the vehicle proximate the receptacle;

the access door allows access to the receptacle when open;

the access door is coupled to an access door switch indicating whether the access door is open; and

the vehicle condition is based on a signal from the access door switch.

10. The method of claim 1 wherein the receptacle comprises a plug detector switch providing an indication of whether a plug is coupled to the receptacle;

and the vehicle condition is based on a signal from the plug detector switch.

11. The method of claim 10 wherein the plug detector switch comprises a pin switch, which is depressed when a plug end of an external power supply cord is coupled with the receptacle.

12. The method of claim 1 wherein the vehicle condition is indicated by determining whether current is being supplied to the battery charger.

13. The method of claim 1 wherein the vehicle condition is indicated by determining whether a voltage source is coupled to the battery charger.

14. The method of claim 1, wherein the vehicle further comprises:

an electric motor;

a transmission coupled to the electric motor; and

an internal combustion engine coupled to the transmission;

the method further comprising;

disabling the electric motor and the internal combustion engine when such vehicle condition is detected.

15. A plug-in vehicle system, comprising:

an electric motor,

a battery electrically coupled to the electric motor;

a battery charger electrically coupled to the battery;

a receptacle coupled to the battery charger, the receptacle being adapted to couple with a plug of an external power supply cord to charge the battery from an external electric power supply;

a driveline mechanically coupled to the electric motor;

wheels coupled to the driveline;

a mechanical restraint coupled to the driveline, the mechanical restraint preventing rotation of at least one wheel when applied; and

an electronic control unit electronically coupled to the vehicle, the electronic control unit preventing release of the mechanical restraint when a vehicle signal indicates one of;

a plug is coupled with the receptacle or an access door proximate the receptacle is open thereby allowing access to the receptacle.

16. The system of claim 15, further comprising:

an access door switch mechanically coupled to the access door and electronically coupled to the electronic control unit, wherein a signal from the access door switch provides the vehicle signal.

17. The system of claim 15 wherein the vehicle signal is based on an indication that one of a voltage and a current is being applied to the battery charger.

18. The system of claim 15, further comprising:

a plug detect switch coupled to the receptacle wherein the plug detect switch is depressed by the plug when it couples with the receptacle and the vehicle signal comprises a signal from the plug detect switch.

19. The system of claim 15, further comprising:

brakes adapted to restrain at least one wheel from rotating wherein the mechanical restraint comprises the brakes.

20. The system of claim 15, further comprising:

a parking gear wheel coupled to the driveline;

a pawl adapted to engage with the parking gear wheel to prevent rotation of the parking gear wheel wherein the mechanical restraint comprises the pawl.

21. The system of claim 20, further comprising:

an operator-actuated gear shift selector coupled to the pawl;

a solenoid proximate the gear shift selector, the solenoid adapted to lock the gear shift selector in place wherein the preventing release comprises maintaining the solenoid in the lock position.

22. A method to prevent a battery-powered vehicle from moving when the battery is being charged by an external power source, the vehicle having a battery, a battery charger coupled to the battery and to a receptacle, a pawl adapted to be engaged with a parking gear wheel coupled to a driveline of the vehicle, and a gear shift selector coupled to the pawl, the gear shift selector having a park position in which the pawl is engaged with the parking gear wheel, the method comprising:

detecting a vehicle condition indicating that an external power supply cord is plugged into the receptacle;

detecting whether a brake pedal coupled to the vehicle is being actuated;

detecting whether an ignition key switch coupled to the vehicle is actuated;

preventing the gear shift selector from moving out of the park position when any one of;

the vehicle condition is detected, the brake pedal is unactuated, and the ignition key switch is unactuated.

23. The method of claim 22 wherein the detecting a vehicle condition comprises one of:

detecting a voltage supply source coupled with the receptacle;

detecting a current flow to the battery charger from an external source;

determining that a plug is coupled to the receptacle by a plug detector; and

determining that an access door proximate the receptacle is open.