Method for determining the transmission output torque for an earth moving machine

• US 6,560,549 B2
• Filed: 12/22/1997
• Issued: 05/06/2003
• Est. Priority Date: 12/22/1997
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Reiners, Eric A., Kough, Bradford A., Fonkalsrud, Andrew O.
• Primary Examiner(s): WACHSMAN, HAL D
• Application Number:
  US08/996,286
• Publication Number:
  US 20020147552A1
• Time in Patent Office: 1,961 Days
• Field of Search: 702/41-44, 702/33, 702/96, 702/101, 702/102, 702/105, 702/115, 702/126, 702/141, 702/142, 702/145-148, 702/175, 702/182-185, 702/FOR-123, 702/FOR.135, 702/FOR.136, 702/FOR-150, 702/FOR.170, 702/FOR.175, 702/173, 702/174, 477/120, 477/107, 477/109, 477/115, 477/118, 477/111, 477/30, 477/904, 477/36, 477/68, 477/69, 477/900, 477/110, 477/15, 477/34, 477/35, 477/37, 477/46, 477/49, 477/124, 743/35, 743/36.R, 743/37, 475/280, 475/281, 475/47, 475/43, 475/46, 475/94, 475/125, 475/126, 475/904, 701/51, 701/50, 701/29, 701/67, 701/68, 701/84, 701/87, 701/90, 701/54, 701/53, 701/93, 731/181, 731/182, 738/623.1, 733/21, 738/623.24, 738/623.25, 738/621.93, 73/10.9, 73/11.1, 73/11.2, 731/16, 731/173, 731/19.R, 738/620.8, 738/622.4, 738/622--86, 738/621.94, 738/621.95, 192/3.23, 192/3.26, 192/3.58, 192/3.3, 192/3.33, 172/4, 172/5, 172/7, 172/8, 180/53.4, 180/249, 177/25-1-, 177/136-141, 177/147
• US Class Current: 702/41
• CPC Class Codes: B60K 23/0808 for varying torque distribution between driven axles, e.g. by transfer clutch
• CPC Class Codes: B60W 2510/105 Output torque
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: F16H 2059/148 Transmission output torque, e.g. measured or estimated torque at output drive shaft
• CPC Class Codes: F16H 59/16 Dynamometric measurement of torque

Abstract

The present invention is adapted to provide a method for determining the torque of a driveshaft. In the preferred embodiment a drivetrain includes a front and a rear drivetrain. The drivetrain is also connected to an engine, torque converter, front and rear axle and a transmission. In one embodiment, the ability to determine the transmission output torque for an earth moving machine includes determining an output torque of the converter and a gear reduction of the engine, and then responsively determining the front and rear driveshaft torque in response to the converter output torque and the engine gear reduction. The driveshaft torque calculations may be performed while the earth moving machine is operating. The resulting front and rear driveshaft torque calculations may be used to determine an axle damage index, or axle life calculations.

Claims

1. A method for determining a torque of a driveshaft located on an machine, the driveshaft being connected to a drivetrain having an engine, a torque converter, a front and rear axle, and a transmission, comprising the steps of:

determining a gear reduction of said transmission;

determining an output torque of said torque converter;

dynamically determining an axle weight ratio; and

determining said driveshaft torque in response to said torque converter output torque, said axle weight ratio, and said transmission gear reduction.

2. The method, as set forth in claim 1, wherein the step of determining said driveshaft torque includes the steps of:

determining a direction of travel of the machine; and

,

responsively determining said driveshaft torque in response to said direction of travel, said torque converter output torque, and said transmission gear reduction.

3. The method, as set forth in claim 1, wherein the step of determining a converter output torque further includes the steps of:

determining a primary torque of said converter;

determining a torque ratio of said converter;

determining an input speed of said converter;

determining an output speed of said converter; and

,

determining said converter output torque in response to said primary torque, said torque ratio, said converter input speed, and said converter output speed.

4. The method as set forth in claim 3 wherein the step of determining said converter output torque includes the steps of:

determining a speed ratio of said converter;

determining said primary torque in response to said converter speed ratio; and

determining said torque ratio in response to said converter speed ratio.

5. The method as set forth in claim 4, wherein the step of determining said driveshaft torque includes the steps of:

determining a front driveshaft torque; and

,

determining a rear driveshaft torque.

6. The method, as set forth in claim 5, including the steps of:

determining said front and said rear driveshaft torque in response to said driveshaft torque, and said axle weight ratio.

7. The method, as set forth in claim 6, wherein the machine has a front axle and a rear axle, and further wherein the step of dynamically determining said axle weight ratio includes the steps of:

determining a weight of said front axle;

determining a weight of said rear axle; and

determining said axle weight ratio in response to said front and rear axle weight.

8. The method, as set forth in claim 7, wherein the step of dynamically determining said axle weight ratio further includes the steps of:

dynamically determining at least one force acting on said front axle;

dynamically determining at least one force acting on said rear axle; and

dynamically determining said axle weight ratio in response to said front and said rear axle weight, and said front and said rear at least one axle force.

9. The method, as set forth in claim 8, wherein the step of dynamically determining said at least one front axle force includes the step of determining a sum of forces acting on said front axle.

10. The method, as set forth in claim 9, wherein the step of dynamically determining said at least one rear axle force includes the step of determining a sum of forces acting on said rear axle.

11. The method, as set forth in claim 10, wherein the machine includes a bucket, and a lift cylinder attached to the bucket, and a tilt cylinder attached to the bucket, wherein the step of determining a sum of forces acting on said front axle further includes the steps of:

determining at least one of a lift cylinder displacement and a lift cylinder pressure of said lift cylinder; and

determining said sum of forces acting on said front axle in response to said one of said lift cylinder displacement and said lift cylinder pressure of said lift cylinder.

12. The method, as set forth in claim 11, wherein the step of determining a sum of forces acting on said front axle further includes the steps of:

determining at least one of a tilt cylinder displacement, and a tilt cylinder pressure of said tilt cylinder; and

determining said sum of forces acting on said front axle in response to said at least one of said tilt cylinder displacement and said tilt cylinder pressure.