Control of regenerative braking during a yaw stability control event

• US 20030230933A1
• Filed: 06/17/2002
• Published: 12/18/2003
• Est. Priority Date: 06/17/2002
• Status: Abandoned Application

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Schneider, Michael John, Brown, Todd Allen
• Application Number:
  US10/064,159
• Publication Number:
  US 20030230933A1
• Time in Patent Office: Days
• US Class Current: 303/146
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2240/22 Yaw angle
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 7/22 Dynamic electric resistor braking, combined with dynamic electric regenerative braking
• CPC Class Codes: B60L 7/26 Controlling the braking effect
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60T 13/586 the retarders being of the electric type
• CPC Class Codes: B60T 2270/613 ESP features related thereto
• CPC Class Codes: B60T 8/1755 Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve road vehicle drive control systems for control of driving stability otherwise than by controlling a particular sub-unit B60W30/02
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2510/207 Oversteer or understeer
• CPC Class Codes: B60W 2720/403 between front and rear axle
• CPC Class Codes: B60W 30/02 Control of vehicle driving stability
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

The present invention is a method and system to control regenerative braking during the operation of a yaw stability control system. The method and system can use feedback control algorithms to monitor and dynamically modify regenerative and non-regenerative braking. The controller can use a simple proportional-integral-derivative feedback controller. A vehicle yaw stability control system can determine if a vehicle is experiencing an oversteer or understeer condition. The controller compares actual brake balance to a desired brake balance. The controller determines if the front axle wheels are overbraked relative to the rear axle wheels or if the rear axle wheels are overbraked relative to the front axle wheels as compared to the desired brake balance. The controller can adjust regenerative braking and non-regenerative braking levels according to the determinations.

Claims

1. A system to control braking for a vehicle during a yaw stability control event, comprising:

a yaw stability control system to determine if the vehicle is experiencing an understeer or oversteer condition;

non-regenerative brakes connected to wheels of at least one axle;

regenerative braking is applied to the wheels of at least one axle; and

a controller comprising an ability to receive input from the yaw stability control system, compare actual brake balance to a desired brake balance, determine if front axle wheels or rear axle wheels are overbraked as compared to the desired brake balance, and adjust regenerative braking and non-regenerative braking levels.

2. The system of claim 1, wherein the controller is a simple proportional-integral-derivative feedback controller.

3. The system of claim 1, wherein the controller adjusts regenerative braking and non-regenerative braking levels over a period of time that provides a quick return to balanced braking and allows a switch between regenerative and non-regenerative braking to be smooth.

4. The system of claim 1, wherein the controller adjusts regenerative braking and non-regenerative braking levels over a period of time between 50 msec and 1 sec.

5. The system of claim 1, wherein:

the non-regenerative brakes are connected to front axle wheels; and

regenerative braking is applied to rear axle wheels.

6. The system of claim 5, wherein:

the controller reduces regenerative braking when the yaw stability control system determines the vehicle is experiencing said oversteer condition and the rear axle wheels are overbraked relative to the front axle wheels.

7. The system of claim 5, wherein:

the controller maintains regenerative braking when the yaw stability control system determines the vehicle is experiencing said understeer condition.

8. The system of claim 5, wherein:

the controller maintains regenerative braking when the yaw stability control system determines the vehicle is experiencing said oversteer condition and the rear axle wheels are not overbraked relative to the front axle wheels.

9. The system of claim 5, wherein:

the non-regenerative brakes are also connected to the rear axle wheels; and

the controller switches from regenerative braking to non-regenerative braking at the rear axle wheels when the yaw stability control system determines the vehicle is experiencing said understeer condition.

10. The system of claim 5 wherein:

the non-regenerative brakes are also connected to the rear axle wheels; and

the controller switches from regenerative braking to non-regenerative braking at the rear axle wheels when the yaw stability control system determines the vehicle is experiencing said oversteer condition and the rear axle wheels are not overbraked relative to the front axle wheels.

11. The system of claim 1, wherein:

the non-regenerative brakes are connected to rear axle wheels; and

regenerative braking is applied to front axle wheels.

12. The system of claim 11, wherein:

the controller reduces regenerative braking when the yaw stability control system determines the vehicle is experiencing said understeer condition and the front axle wheels are overbraked relative to the rear axle wheels.

13. The system of claim 11, wherein:

the controller maintains regenerative braking when the yaw stability control system determines the vehicle is experiencing said oversteer condition.

14. The system of claim 11, wherein:

the controller maintains regenerative braking when the yaw stability control system determines the vehicle is experiencing said understeer condition and the front axle wheels are not overbraked relative to the rear axle wheels.

15. The system of claim 11, wherein:

the non-regenerative brakes are also connected to the front axle wheels; and

the controller switches from regenerative braking to non-regenerative braking at the front axle wheels when the yaw stability control system determines the vehicle is experiencing said oversteer condition.

16. The system of claim 11, wherein:

the non-regenerative brakes are also connected to the front axle wheels; and

the controller switches from regenerative braking to non-regenerative braking at the front axle wheels when the yaw stability control system determines the vehicle is experiencing said understeer condition and the front axle wheels are not overbraked relative to the rear axle wheels.

17. A method to control regenerative braking for a vehicle having a yaw stability control system, an ability to provide regenerative braking torque to wheels of at least one axle, non-regenerative brakes connected to the wheels of at least one axle, the method comprising the steps of:

determining in the yaw stability control system if the vehicle is experiencing an understeer or oversteer condition; and

controlling the vehicle by receiving input from the yaw stability control system, comparing actual brake balance to a desired brake balance, determining if front axle wheels or rear axle wheels are overbraked as compared to the desired brake balance, and adjusting regenerative braking and non-regenerative braking levels.

18. The method of claim 17, wherein the step of controlling the vehicle comprises using a simple proportional-integral-derivative feedback controller.

19. The method of claim 17, wherein the step of adjusting regenerative braking and non-regenerative braking levels is accomplished over a period of time that provides a quick return to balanced braking and allows a switch between regenerative braking and non-regenerative braking to be smooth.

20. The method of claim 17, wherein the step of adjusting regenerative braking and non-regenerative braking levels is accomplished over a period of time between 50 msec and 1 sec.

21. The method of claim 17, wherein:

regenerative braking is applied to the rear axle wheels; and

the non-regenerative brakes are connected to the front axle wheels.

22. The method of claim 21, wherein the step of adjusting regenerative braking and non-regenerative braking levels comprises the step of:

reducing regenerative braking when the yaw stability control system determines the vehicle is experiencing said oversteer condition and the rear axle wheels are overbraked relative to the front axle wheels.

23. The method of claim 21, wherein the step of adjusting regenerative braking and non-regenerative braking levels comprises the step of:

maintaining regenerative braking when the yaw stability control system determines the vehicle is experiencing said understeer condition.

24. The method of claim 21, wherein the step of adjusting regenerative braking and non-regenerative braking levels comprises the step of:

maintaining regenerative braking when the yaw stability control system determines the vehicle is experiencing said oversteer condition and the rear axle wheels are not overbraked relative to the front axle wheels.

25. The method of claim 21, wherein:

the non-regenerative brakes are also connected to the rear axle wheels; and

the step of adjusting regenerative braking and non-regenerative braking levels comprises switching from regenerative braking to non-regenerative braking at the rear axle wheels when the yaw stability control system determines the vehicle is experiencing said understeer condition.

26. The method of claim 21, wherein:

the non-regenerative brakes are also connected to the rear axle wheels; and

the step of adjusting regenerative braking and non-regenerative braking levels comprises switching from regenerative braking to non-regenerative braking at the rear axle wheels when the yaw stability control system determines the vehicle is experiencing said oversteer condition and the rear axle wheels are not overbraked relative to the front axle wheels.

27. The method of claim 17, wherein:

regenerative braking is applied to the front axle wheels; and

the non-regenerative brakes are connected to the rear axle wheels.

28. The method of claim 27, wherein the step of adjusting regenerative braking and non-regenerative braking levels comprises the step of:

reducing regenerative braking when the yaw stability control system determines the vehicle is experiencing said understeer condition and the front axle wheels are overbraked relative to the rear axle wheels.

29. The method of claim 27, wherein the step of adjusting regenerative braking and non-regenerative braking levels comprises the step of:

maintaining regenerative braking when the yaw stability control system determines the vehicle is experiencing said oversteer condition.

30. The method of claim 27, wherein the step of adjusting regenerative braking and non-regenerative braking levels comprises the step of:

maintaining regenerative braking when the yaw stability control system determines the vehicle is experiencing said understeer condition and the front axle wheels are not overbraked relative to the rear axle wheels.

31. The method of claim 27, wherein:

the non-regenerative brakes are also connected to the front axle wheels; and

the step of adjusting regenerative braking and non-regenerative braking levels comprises switching from regenerative braking to non-regenerative braking at the front axle wheels when the yaw stability control system determines the vehicle is experiencing said oversteer condition.

32. The method of claim 27, wherein:

the non-regenerative brakes are also connected to the front axle wheels; and

the step of adjusting regenerative braking and non-regenerative braking levels comprises switching from regenerative braking to non-regenerative braking at the front axle wheels when the yaw stability control system determines the vehicle is experiencing said understeer condition and the front axle wheels are not overbraked relative to the rear axle wheels.

33. An article of manufacture to control regenerative braking for a vehicle comprising:

a yaw stability control system;

an ability to provide regenerative braking torque to wheels of at least one axle;

non-regenerative brakes connected to the wheels of at least one axle;

a controller; and

a control system embodied within the controller for directing the controller to control regenerative braking and non-regenerative braking during operation of the yaw stability control system.

34. An automotive vehicle, comprising:

a yaw stability control system;

an ability to provide regenerative braking torque to wheels of at least one axle;

non-regenerative brakes connected to the wheels of at least one axle;

a controller; and

a control system embodied within the controller for directing the controller to control regenerative braking and non-regenerative braking during operation of the yaw stability control system.