Method and system for progressive engagement of all-wheel drive

• US 6,591,179 B1
• Filed: 01/04/2002
• Issued: 07/08/2003
• Est. Priority Date: 01/04/2002
• Status: Expired due to Term

• Current Assignee: BWI Company Limited SA (Shougang Corporation)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Krueger, Eric E., Check, Michael J., Loudon, Steven P.
• Primary Examiner(s): Camby, Richard M.
• Application Number:
  US10/040,329
• Publication Number:
  US 20030130782A1
• Time in Patent Office: 550 Days
• Field of Search: 701/91, 701/69, 701/70, 701/71, 701/72, 701/74, 701/75, 701/82, 701/83, 701/84, 701/90, 180/234, 180/245, 180/246, 180/248, 180/249
• US Class Current: 701/91
• CPC Class Codes: B60K 17/3462 with means for changing distribution of torque between front and rear wheels
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60T 2270/12 for all-wheel drive vehicles
• CPC Class Codes: B60T 2270/202 for all-wheel drive vehicles
• CPC Class Codes: B60T 2270/302 for all-wheel drive vehicles
• CPC Class Codes: B60T 8/1769 specially adapted for vehicles having more than one driven axle, e.g. four-wheel drive vehicles
• CPC Class Codes: B60T 8/322 Systems specially adapted for vehicles driven by more than one axle, e.g. Four Wheel-Drive vehicles
• CPC Class Codes: B60W 2050/0022 Gains, weighting coefficients or weighting functions
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: Y10T 82/16754 Means to feed work axially

Abstract

The invention provides a method of progressive engagement of all-wheel drive for a mobile vehicle. A set of vehicle parameters is sensed, and an all-wheel drive lock value is determined based on the sensed set of vehicle parameters. Vehicle subsystem control activation is determined, and the all-wheel drive lock value is adjusted based on the vehicle subsystem control activation determination. An all-wheel drive controller is engaged based on the adjusted all-wheel drive lock value.

Claims

1. A method of progressive engagement of all-wheel drive for a mobile vehicle, comprising:

sensing a set of vehicle parameters;

determining an all-wheel drive lock value based on the sensed set of vehicle parameters;

determining vehicle subsystem control activation;

adjusting the all-wheel drive lock value based on the vehicle subsystem control activation determination;

engaging an all-wheel drive controller based on the adjusted all-wheel drive lock value; and

controlling at least one differential based on the adjusted all-wheel drive lock value.

2. The method of claim 1 wherein the sensed set of vehicle parameters comprises lateral acceleration, steering wheel angle, yaw rate, and wheel speed.

3. The method of claim 1 wherein the all-wheel drive lock value is based on a ratio of a sensed lateral acceleration and a surface capability value.

4. The method of claim 3 wherein the surface capability value is computed from the sensed set of vehicle parameters.

5. The method of claim 1 wherein the vehicle subsystem control activation determination comprises determining whether a vehicle anti-lock brake subsystem is active, and adjusting the all-wheel drive lock value to an unlocked condition if the vehicle anti-lock brake subsystem is active.

6. The method of claim 1 wherein the vehicle subsystem control activation determination comprises determining whether a vehicle traction control subsystem is active, and adjusting the all-wheel drive lock value based on a traction control subsystem gain value if the vehicle traction control subsystem is active.

7. The method of claim 6 wherein the traction control subsystem gain value is a function of the surface capability value.

8. The method of claim 1 wherein the vehicle subsystem control activation determination comprises determining whether a vehicle stability enhancement subsystem is active, and adjusting the all-wheel drive lock value based on a stability enhancement subsystem gain value if the vehicle stability enhancement subsystem is active.

9. The method of claim 8 wherein the stability enhancement subsystem gain value is a function of the surface capability value.

10. The method of claim 1 wherein no adjustment to the all-wheel drive lock value is made if it is determined that the anti-lock brake subsystem is not active, the traction control subsystem is not active, and the vehicle stability enhancement subsystem is not active.

11. A computer usable medium including a program for progressive engagement of all-wheel drive, comprising:

computer program code to determine an all-wheel drive lock value based on the sensed set of vehicle parameters;

computer program code to determine vehicle subsystem control activation;

computer program code to adjust the all-wheel drive lock value based on the vehicle subsystem control activation determination; and

computer program code to engage an all-wheel drive controller based on the adjusted all-wheel drive lock value;

computer program code to control at least one differential based on the adjusted all-wheel drive lock value.

12. The computer usable medium of claim 11 wherein the sensed set of vehicle parameters comprises lateral acceleration, steering wheel angle, yaw rate, and wheel speed.

13. The computer usable medium of claim 11 wherein the all-wheel drive lock value is based on a ratio of a sensed lateral acceleration and a surface capability value.

14. The computer usable medium of claim 13 wherein the surface capability value is computed from the sensed set of vehicle parameters.

15. The computer usable medium of claim 11 wherein the vehicle subsystem control activation determination comprises determining whether a vehicle anti-lock brake subsystem is active, and adjusting the all-wheel drive lock value to an unlocked condition if the vehicle anti-lock brake subsystem is active.

16. The computer usable medium of claim 11 wherein the vehicle subsystem control activation determination comprises determining whether a vehicle traction control subsystem is active, and adjusting the all-wheel drive lock value based on a traction control subsystem gain value if the vehicle traction control subsystem is active.

17. The computer usable medium of claim 16 wherein the traction control subsystem gain value is a function of the surface capability value.

18. The computer usable medium of claim 11 wherein the vehicle subsystem control activation determination comprises determining whether a vehicle stability enhancement subsystem is active, and adjusting the all-wheel drive lock value based on a stability enhancement subsystem gain value if the vehicle stability enhancement subsystem is active.

19. The computer usable medium of claim 18 wherein the stability enhancement subsystem gain value is a function of the surface capability value.

20. The computer usable medium of claim 11 wherein no adjustment to the all-wheel drive lock value is made if it is determined that the anti-lock brake subsystem is not active, the traction control subsystem is not active, and the vehicle stability enhancement subsystem is not active.

21. A system for progressive engagement of all-wheel drive, comprising:

means for sensing a set of vehicle parameters;

means for determining an all-wheel drive lock value based on the sensed set of vehicle parameters;

means for determining vehicle subsystem control activation;

means for adjusting the all-wheel drive lock value based on the vehicle subsystem control activation determination;

means for engaging an all-wheel drive controller based on the adjusted all-wheel drive lock value, and

means for controlling at least one differential based on the adjusted all-wheel drive lock value.