Machine control system and method

• US 8,058,829 B2
• Filed: 11/25/2008
• Issued: 11/15/2011
• Est. Priority Date: 11/25/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Anderson, Randall T.
• Primary Examiner(s): Masih; Karen
• Application Number:
  US12/292,748
• Publication Number:
  US 20100127654A1
• Time in Patent Office: 1,085 Days
• Field of Search: 318/432, 318/433, 318/434, 701/54, 701/84, 180/648, 180/197
• US Class Current: 318/432
• CPC Class Codes: E02F 9/202 Mechanical transmission, e.g. clutches, gears clutches per se F16D, gears per se F16H
• CPC Class Codes: E02F 9/2253 Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
• CPC Class Codes: F16H 61/472 for achieving a target output torque
• CPC Class Codes: F16H 61/478 for preventing overload, e.g. high pressure limitation

Abstract

An electronic control module for a machine may include instructions for performing a method. The method may include obtaining a total torque load limit for one or more hydrostatic transmission loops in the machine. The method may also include allocating the total torque load limit between the one or more hydrostatic transmission loops in the form of one or more lower level torque load limits.

Claims

1. An electronic control module for a machine including instructions for performing a method, the method comprising:

determining a torque load limit for a torque consuming element;

determining a pressure limit for the torque consuming element based at least in part on the torque load limit;

determining a displacement for the torque consuming element based at least in part on the pressure limit; and

operating the torque consuming element at the determined displacement.

2. The electronic control module of claim 1, wherein operating the torque consuming element at the determined displacement serves to maintain an amount of torque consumed by the torque consuming element at or below the torque load limit.

3. The electronic control module of claim 1, wherein operating the torque consuming element at the determined displacement serves to maintain a pressure level in the torque consuming element at or below the pressure limit.

4. The electronic control module of claim 3, wherein maintaining the pressure level at or below the pressure limit includes switching operation of the torque consuming element from a first state to a second state based at least in part on a difference between the pressure level in the torque consuming element and the pressure limit.

5. The electronic control module of claim 4, wherein operating the torque consuming element in the second state reduces the pressure level faster than operating the torque consuming element in the first state.

6. The electronic control module of claim 1, wherein determining the displacement for the torque consuming element includes obtaining a displacement for a component of the torque consuming element.

7. The electronic control module of claim 6, wherein determining the displacement for the torque consuming element includes determining if the obtained displacement falls outside of a first predetermined range, and if so, limiting the obtained displacement to a second predetermined range.

8. The electronic control module of claim 7, wherein the first predetermined range at least partially overlaps with the second predetermined range.

9. The electronic control module of claim 1, wherein determining the displacement for the torque consuming element includes determining whether conditions for a first state exist, wherein adjusting operation of a first component of the torque consuming element affects performance of the torque consuming element.

10. The electronic control module of claim 9, wherein determining the displacement for the torque consuming element includes determining whether conditions for a second state exist, wherein adjusting operation of a second component of the torque consuming element affects performance of the torque consuming element.

11. The electronic control module of claim 10, wherein determining the displacement for the torque consuming element includes selecting a displacement for the torque consuming element associated with the first state if conditions for the first state exist, and with the second state if conditions for the second state exist.

12. The electronic control module of claim 1, wherein operating the torque consuming element at the determined displacement serves to maintain a speed of a prime mover that provides torque to the torque consuming element within a predetermined range of operation.

13. A machine, comprising:

a prime mover configured to generate torque;

a torque consuming device configured to consume torque generated by the prime mover; and

a control system operable to;

obtain a torque load limit for a torque consuming element of the torque consuming device based at least in part on the torque generated by the prime mover,

obtain a pressure limit for the torque consuming element based at least in part on the torque load limit,

obtain a displacement for the torque consuming element based at least in part on the pressure limit, and

operate the torque consuming element at the obtained displacement.

14. The machine of claim 13, wherein the torque consuming device includes a traction assembly.

15. The machine of claim 14, wherein the traction assembly includes a left side traction assembly and a right side traction assembly.

16. The machine of claim 14, wherein the torque consuming element includes a transmission assembly configured to drive the traction assembly.

17. The machine of claim 16, wherein the transmission assembly includes a pump and a motor.

18. The machine of claim 17, wherein the control system is operable to obtain a pump displacement and a motor displacement, and operate the pump and the motor at the pump displacement and the motor displacement, respectively.