Machine control system and method

• US 8,450,960 B2
• Filed: 09/23/2011
• Issued: 05/28/2013
• 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:
  US13/242,900
• Publication Number:
  US 20120029768A1
• Time in Patent Office: 613 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:

obtaining a total torque load limit for two or more torque consuming elements of the machine; and

allocating the total torque load limit between the two or more torque consuming elements in the form of two or more lower level torque load limits,

wherein the machine includes a transmission including a first of the two or more torque consuming elements, and

wherein the first torque consuming element includes a pump.

2. The electronic control module of claim 1, wherein the transmission includes a hydrostatic transmission, and the hydrostatic transmission includes the pump, and

wherein obtaining the total torque load limit for the two or more torque consuming elements includes obtaining a total torque load limit for the pump and a second of the two or more torque consuming elements, and allocating the total torque load limit between the two or more torque consuming elements includes allocating the total torque load limit for each of the pump and the second torque consuming element in the form of two lower level torque load limits.

3. The electronic control module of claim 1, wherein the transmission includes two hydrostatic transmissions, and

wherein obtaining the total torque load limit for the two or more torque consuming elements includes obtaining a total torque load limit for each of the two hydrostatic transmissions, and allocating the total torque load limit between the two or more torque consuming elements includes allocating the total torque load limit for each of the two hydrostatic transmissions.

4. The electronic control module of claim 3, wherein allocating the total torque load limit includes providing an overrunning torque in a first of the hydrostatic transmissions to a second of the hydrostatic transmissions.

5. The electronic control module of claim 1, wherein the method further includes:

determining a pressure limit for at least one of the torque consuming elements based at least in part on the torque load limit associated with the at least one torque consuming element;

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

operating the at least one torque consuming element at the displacement.

6. The electronic control module of claim 5, wherein operating the at least one torque consuming element at the determined displacement serves to maintain an amount of torque consumed by the at least one torque consuming element at or below the torque load limit associated with the at least one torque consuming element.

7. The electronic control module of claim 5, wherein operating the at least one torque consuming element at the displacement serves to maintain a pressure level in the at least one torque consuming element at or below the pressure limit.

8. The electronic control module of claim 7, wherein maintaining the pressure level at or below the pressure limit includes switching operation of the at least one 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 at least one torque consuming element and the pressure limit.

9. The electronic control module of claim 8, wherein operating the at least one torque consuming element in the second state reduces the pressure level faster than operating the at least one torque consuming element in the first state.

10. The electronic control module of claim 5, wherein determining the displacement for the at least one torque consuming element includes obtaining a displacement for a component of the at least one torque consuming element.

11. The electronic control module of claim 10, wherein determining the displacement for the at least one torque consuming element includes determining whether the obtained displacement for the component falls outside of a first predetermined range, and if so, limiting the obtained displacement to a second predetermined range.

12. The electronic control module of claim 11, wherein the first predetermined range at least partially overlaps with the second predetermined range.

13. The electronic control module of claim 5, wherein determining the displacement for the at least one torque consuming element includes determining whether conditions for a first state exist, wherein adjusting operation of a first component of the at least one torque consuming element affects performance of the at least one torque consuming element.

14. The electronic control module of claim 13, wherein determining the displacement for the at least one torque consuming element includes determining whether conditions for a second state exist, wherein adjusting operation of a second component of the at least one torque consuming element affects performance of the torque consuming element.

15. The electronic control module of claim 14, wherein determining the displacement for the at least one torque consuming element includes selecting a displacement for the at least one 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.

16. The electronic control module of claim 5, wherein operating the at least one torque consuming element at the determined displacement serves to maintain a speed of a prime mover that provides torque to the at least one torque consuming element within a predetermined range of operation.

17. 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 total torque load limit for two or more torque consuming elements of the machine; and

allocate the total torque load limit between the two or more torque consuming elements in the form of two or more lower level torque load limits,

wherein a first of the two or more torque consuming elements includes a transmission assembly, and

wherein the transmission assembly includes a pump and a motor.

18. The machine of claim 17, wherein the first torque consuming element further includes a traction assembly.

19. The machine of claim 18, wherein the traction assembly includes a left side traction assembly and a right side traction assembly.

20. The machine of claim 18, wherein the transmission assembly is configured to drive the traction assembly.

21. 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.

22. A method for controlling two or more torque consuming elements of a machine, the method comprising:

obtaining a total torque load limit for two or more torque consuming elements of the machine;

allocating the total torque load limit between the two or more torque consuming elements in the form of two or more lower level torque load limits; and

operating the two or more torque consuming elements based on the allocation,

wherein the machine includes a transmission including a first of the two or more torque consuming elements, and

wherein the first torque consuming element includes a pump.

23. The method of claim 22, wherein the transmission includes a hydrostatic transmission, and the hydrostatic transmission includes the pump, and

wherein obtaining the total torque load limit for the two or more torque consuming elements includes obtaining a total torque load limit for the pump and a second of the two or more torque consuming elements, and allocating the total torque load limit between the two or more torque consuming elements includes allocating the total torque load limit for each of the pump and the second torque consuming element in the form of two lower level torque load limits.

24. The method of claim 22, wherein the transmission includes two hydrostatic transmissions, and

wherein obtaining the total torque load limit for the two or more torque consuming elements includes obtaining a total torque load limit for each of the two hydrostatic transmissions, and allocating the total torque load limit between the two or more torque consuming elements includes allocating the total torque load limit for each of the two hydrostatic transmissions.

25. The method of claim 24, wherein allocating the total torque load limit includes providing an overrunning torque in a first of the hydrostatic transmissions to a second of the hydrostatic transmissions.