Method and system to prevent vehicle driveaway during battery charging

• US 8,393,423 B2
• Filed: 06/18/2009
• Issued: 03/12/2013
• 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: Gwozdek, Thomas M., Lathrop, James A., Mils, Jerry, Lovitt, Karin
• Primary Examiner(s): Restifo, Jeffrey J
• Application Number:
  US12/487,069
• Publication Number:
  US 20100320018A1
• Time in Patent Office: 1,363 Days
• Field of Search: 180/65.27, 180/65.1, 180/65.21, 320/107
• 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 an onboard battery is being charged, comprising:

engaging a pawl with a parking gear wheel coupled to a driveline of the vehicle when an external power supply cord is plugged into a battery charging receptacle of the vehicle.

2. The method of claim 1 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

wherein the method further comprises preventing disengagement of the pawl by preventing the gear shift selector from moving out of the park position.

3. 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 wherein the method further comprises preventing a gear shift selector from being released based on a signal from the plug detector switch.

4. The method of claim 3 wherein the plug detector switch comprises a pin switch, which is depressed when a plug end of the external power supply cord is coupled with the receptacle.

5. The method of claim 1, further comprising preventing a gear shift selector from being released when current is being supplied to the battery from the receptacle.

6. The method of claim 1, further comprising preventing a gear shift selector from being released when a voltage source is coupled to the receptacle.

7. 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 while the external power supply cord is plugged into the receptacle.

8. A vehicle having a traction motor coupled to a battery, comprising:

a receptacle coupled to the battery and adapted to couple with a plug of an external power supply cord to charge the battery;

a parking gear wheel; and

a pawl adapted to engage with the parking gear wheel to prevent rotation of the parking gear wheel when a plug is coupled with the receptacle or an access door proximate the receptacle is open.

9. A vehicle system, comprising:

a traction motor coupled to a battery;

a parking gear wheel;

a pawl that selectively engages the parking gear wheel during charging of the battery by an external power supply;

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

a solenoid proximate the gear shift selector and adapted to lock the gear shift selector in place during charging of the battery by the external power supply.

10. 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.

11. The method of claim 10 wherein 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.