SYSTEM AND METHOD FOR CONTROLLING ACTIVATION OF A POWER SOURCE OF A HYBRID ELECTRIC VEHICLE

• US 20050273225A1
• Filed: 08/02/2005
• Published: 12/08/2005
• Est. Priority Date: 09/10/2003
• Status: Active Grant

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Bailey, Kathleen, Masterson, Brandon, Yamazaki, Mark, Brigham, David
• Granted Patent: US 7,412,310 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 903/905 Combustion engine

Abstract

A system and method of controlling activation of a power source of a hybrid electric vehicle. The method includes determining a vehicle speed, determining an operating state of a brake system, and controlling activation of the power source based on at least one of the vehicle speed and the operating state of the brake system.

Claims

1. A method of controlling activation of a power source of a hybrid electric vehicle having primary and secondary power sources and a brake system, the method comprising:

determining a vehicle speed;

determining an operating state of the brake system;

activating the primary power source when (1) the vehicle speed is less than a first threshold value and the brake system is in a released condition, or (2) the vehicle speed exceeds a second threshold value, or (3) a third threshold value has been exceeded; and

deactivating the primary power source when the vehicle speed value is less than the first threshold value and the brake system is not in the released condition.

2. The method of claim 1 wherein the third threshold value is exceeded when a target torque value exceeds a threshold torque value.

3. The method of claim 1 wherein the third threshold value is indicative of a torque limit of an electrical machine.

4. The method of claim 1 wherein the third threshold value is exceeded when a target power value exceeds a threshold power value.

5. The method of claim 1 wherein the third threshold value is indicative of a performance limitation of the secondary power source.

6. The method of claim 1 wherein the primary power source is deactivated when the vehicle speed is not less than the first threshold value and not greater than the second threshold value and the third threshold value is not exceeded.

7. The method of claim 1 wherein the first threshold value is less than the second threshold value.

8. The method of claim 1 wherein brake system is in a released condition when a brake sensor does not detect actuation of a brake pedal.

9. A system for controlling activation of a power source of a hybrid electric vehicle, the system comprising:

primary and secondary power sources;

a brake system for braking a vehicle wheel;

a brake signal;

an acceleration request signal; and

a vehicle speed signal;

a wheel drive signal indicative of at least one of a target torque value and a target power value;

wherein the primary power source is activated when (1) the vehicle speed signal is less than a first threshold value and the brake signal indicates that brake actuation is not requested, or (2) the vehicle speed signal exceeds a second threshold value, or (3) the acceleration request signal is indicative a vehicle acceleration request and the wheel drive signal exceeds a torque threshold value and/or a power threshold value; and

the primary power source is deactivated when the vehicle speed signal is less than the first threshold value and the brake signal indicates that brake actuation is requested.

10. The system of claim 9 wherein the primary power source is an engine.

11. The system of claim 9 wherein the secondary power source is a voltage source.

12. The system of claim 9 wherein the primary and secondary power sources are adapted to selectively drive the vehicle wheel to propel the hybrid electric vehicle.

13. The system of claim 9 wherein the brake signal is provided by a brake pedal sensor.

14. The system of claim 9 wherein the acceleration signal is provided by an accelerator pedal sensor.

15. The system of claim 9 wherein the torque threshold value is based on the acceleration request signal and a selected gear ratio of the power transfer unit.

16. The system of claim 9 wherein the power threshold value is based on the acceleration request signal and a selected gear ratio of the power transfer unit.

17. The system of claim 9 wherein the target power value is based on the target torque value and the vehicle speed value.

18. The system of claim 9 wherein the hybrid electric vehicle further comprises a first wheel set adapted to be driven by the primary and/or secondary power sources and a second wheel set adapted to be driven by the secondary power source.

19. The system of claim 9 wherein the hybrid electric vehicle further comprises a first wheel set adapted to be driven by a power transfer system powered by the primary and/or secondary power sources and a second wheel set having an electrical machine mechanically driven by the power transfer system.