Method and system of determining an acceptable torque level to be applied to at least one clutch pack of an automobile

• US 6,360,156 B1
• Filed: 11/01/2000
• Issued: 03/19/2002
• Est. Priority Date: 11/01/2000
• Status: Expired due to Term

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Wilmanowicz, Marek L., Morganroth, David
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): MANCHO, RONNIE M
• Application Number:
  US09/703,996
• Time in Patent Office: 503 Days
• Field of Search: 701/69, 701/56, 701/61, 701/67, 701/82, 701/84, 701/51-54, 701/71-75, 701/87-95, 738/621.91, 731/16, 738/622.8, 734/88, 180/197, 180/233, 180/248, 180/247, 180/249, 303/121, 303/143, 303/190, 475/86, 475/150, 475/89, 477/125, 477/105, 477/110, 477/62, 477/43, 477/63, 477/78, 477/121, 477/108, 477/176
• US Class Current: 701/69
• CPC Class Codes: B60K 17/20 in which the differential movement is limited
• CPC Class Codes: B60K 17/3462 with means for changing distribution of torque between front and rear wheels
• CPC Class Codes: B60K 17/3505 with self-actuated means, e.g. by difference of speed
• CPC Class Codes: B60K 23/04 for differential gearing
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/28 Wheel speed

Abstract

A method is provided for determining an acceptable torque level to be applied to at least one clutch pack (of an automobile) which includes the requirement of internal slip to transmit torque. The automobile includes a plurality of wheels. A velocity is sensed at each of the plurality of wheels of the automobile. A speed information value is calculated. The speed information value is a function of the sensed velocities at each of the plurality of wheels. The speed information value is then compared with a calibration table. Finally, the acceptable torque level is determined primarily from the calibration table based on the speed information value.

Claims

1. A method of determining an acceptable torque level to be applied to at least one clutch pack of an automobile, the automobile including a plurality of wheels, comprising:

sensing a velocity at each of the plurality of wheels of the automobile;

calculating a speed information value as a function of the sensed velocities at each of the plurality of wheels;

comparing the speed information value with a calibration table; and

determining the acceptable torque level from the calibration table based on the speed information value.

2. The method of claim 1, further comprising determining a current torque level applied to each of the at least one clutch packs.

3. The method of claim 2, further comprising comparing the acceptable torque level to the current torque level.

4. The method of claim 3, further comprising reducing the current torque level.

5. The method of claim 1, wherein the plurality of wheels comprises a first wheel, a second wheel, a third wheel and a fourth wheel;

and wherein the speed information value is calculated by taking the difference between an input value and each of the sensed velocities at the third wheel and at the fourth wheel.

6. The method of claim 5, wherein the input value is the average of the sensed velocities at the first wheel and the second wheel.

7. The method of claim 1, wherein the automobile includes an all-wheel drive transmission system.

8. The method of claim 7, wherein the all-wheel drive transmission system comprises a torque-on-demand all-wheel drive transmission system.

9. The method of claim 8, wherein each of the at least one clutch packs requires a slip value to transmit torque.

10. The method of claim 1, wherein the acceptable torque level is determined periodically.

15. The program of claim 1, wherein the plurality of wheels comprises a first wheel, a second wheel, a third wheel and a fourth wheel;

and wherein computer readable program code calculates the speed information value by taking the difference between an input value and each of the sensed velocities at the third wheel and at the fourth wheel.

11. A computer usable medium storing a program for determining an acceptable torque level to be applied to at least one clutch pack of an automobile, the automobile including a plurality of wheels, comprising:

computer readable program code that senses a velocity each of the plurality of wheels of the automobile;

computer readable program code that calculates a speed information value as a function of the sensed velocities at each of the plurality of wheels;

computer readable program code that compares the speed information value with a calibration table; and

computer readable program code that determines the acceptable torque level from the calibration table based on the speed information value.

12. The program of claim 11, further comprising:

computer readable program code that determines a current torque level applied to each of the at least one clutch packs.

13. The program of claim 12, further comprising:

computer readable program code that compares the acceptable torque level to the current torque level.

14. The program of claim 13, further comprising:

computer readable program code that reduces the current torque level.

16. A system for determining an acceptable torque level to be applied to at least one clutch pack of an automobile, the automobile including a plurality of wheels, comprising:

sensing means for sensing a velocity at each of the plurality of wheels of the automobile;

calculating means for calculating a speed information value as a function of the sensed velocities at each of the plurality of wheels;

comparing means for comparing the speed information value with a calibration table; and

determining means for determining the acceptable torque level from the calibration table based on the speed information value.

17. The system of claim 16, further comprising:

means for determining a current torque level applied to each of the at least one clutch packs.

18. The system of claim 17, further comprising:

means for comparing the acceptable torque level to the current torque level.

19. The system of claim 18, further comprising:

means for reducing the current torque level.

20. The system of claim 19, wherein the plurality of wheels comprises a first wheel, a second wheel, a third wheel and a fourth wheel;

and wherein the speed information value is calculated by taking the difference between an input value and each of the sensed velocities at the third wheel and at the fourth wheel.