Positioning system for an excavating work machine

• US 7,079,931 B2
• Filed: 12/10/2003
• Issued: 07/18/2006
• Est. Priority Date: 12/10/2003
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Koehrsen, Craig Lawrence, Sahm, William Charles
• Primary Examiner(s): Beaulieu, Yonel
• Application Number:
  US10/731,250
• Publication Number:
  US 20050131610A1
• Time in Patent Office: 951 Days
• Field of Search: 701/50, 374/14, 414/699
• US Class Current: 701/50
• CPC Class Codes: E02F 3/431 for bucket-arms, front-end loaders, dumpers or the like

Abstract

A system and method for determining a position of a work tool of a work machine is provided. A desired surface configuration for a geographic location is identified. A mode of operation for the work machine is selected from one of a first mode and a second mode depending on surface configurations. The position of a work tool mounted on the work machine is sensed and the rotational angle of a swing assembly mounting the work tool is sensed. The location of the work tool is determined relative to the surface configuration based on the sensed position of the work tool when the work machine is operating in the first mode. The location of the work tool is determined relative to the desired surface configuration based on the sensed position of the work tool and the sensed rotational angle of the swing assembly when operating in the second mode.

Claims

1. A method of determining a position of a ground engaging tool of a work machine, comprising:

identifying a desired surface configuration for a geographic location;

selecting a mode of operation for the work machine from one of a first operating mode when the desired surface configuration has a first type of surface configuration and a second operating mode when the desired surface configuration has a second type of surface configuration;

sensing the position of the ground engaging tool mounted on the work machine;

sensing a rotational angle of a swing assembly mounting the ground engaging tool;

determining the location of the ground engaging tool relative to the desired surface configuration based on the sensed position of the ground engaging tool, independently of the rotational angle of the swing assembly, when the work machine is operating in the first operating mode; and

determining the location of the ground engaging tool relative to the desired surface configuration based on the sensed position of the ground engaging tool and the sensed rotational angle of the swing assembly when the work machine is operating in the second operating mode.

2. The method of claim 1, further including displaying a representation of the location of the ground engaging tool relative to the desired surface configuration.

3. The method of claim 1, wherein the desired surface configuration is expressed as a desired slope angle.

4. The method of claim 3, wherein the second operating mode is a plane mode and the second type of surface configuration has a substantially planar surface having the desired slope angle.

5. The method of claim 4, further including establishing a reference angle for the swing assembly, wherein the reference angle is indicative of a line extending substantially perpendicular to a border of the desired surface plane.

6. The method of claim 3, wherein the first mode of operation is a curved mode and the first type of surface configuration has an arcuate shape having the desired slope angle.

7. The method of claim 1, further including automatically moving the ground engaging tool to remove material from the geographic location to obtain the desired surface configuration.

8. A positioning system for a work machine having a ground engaging tool and a rotatable swing assembly mounting the ground engaging tool, comprising:

an input device configured to allow an operator to select an operating mode from one of a first operating mode and a second operating mode and to allow the operator to enter a desired surface configuration for a geographic location;

a position sensing system operatively connected to the swing assembly and the ground engaging tool, the position sensing system is configured to provide an indication of a position of the ground engaging tool and an indication of a rotational angle of the swing assembly; and

a control operable to determine the location of the ground engaging tool relative to the desired surface configuration based on the sensed position of the ground engaging tool, independently of the rotational angle of the swing assembly, when the first operating mode is selected, the control further operable to determine the location of the ground engaging tool relative to the desired surface configuration based on the sensed position of the ground engaging tool and the sensed rotational angle of the swing assembly when the second operating mode is selected.

9. The system of claim 8, further including a display device configured to provide a display having a representation of the location of the ground engaging tool relative to the desired surface configuration.

10. The system of claim 8, wherein the ground engaging tool is mounted on a work implement linkage and the position sensing system includes a series of displacement sensors operatively connected to the work implement linkage.

11. The system of claim 8, wherein the second operating mode is a plane mode and the input device is configured to allow an operator to enter a desired slope angle for a desired surface plane to be excavated from the geographic location and to allow the operator to set a reference angle for the swing assembly when the second operating mode is selected.

12. The system of claim 11, wherein the reference angle of the swing assembly is indicative of a line extending substantially perpendicular to a border of the desired surface plane.

13. A method of determining a position of a ground engaging tool of a work machine, comprising:

identifying a desired surface configuration for a particular geographic location, wherein the desired surface configuration is a desired plane surface having a predetermined slope angle;

adjusting the position of a swing assembly to rotate a work implement linkage relative to the desired location of the desired plane surface;

setting a reference angle for the swing assembly;

moving a ground engaging tool mounted on the work implement linkage to excavate material from the geographic location;

sensing the position of the ground engaging tool mounted on the work implement linkage;

sensing a rotational angle of the swing assembly relative to the reference angle; and

determining the location of the ground engaging tool relative to the desired plane surface based on the sensed position of the ground engaging tool and the sensed rotational angle of the swing assembly.

14. The method of claim 13, wherein the reference angle for the swing assembly is set when the work implement linkage extends along a line that is substantially perpendicular to a border of the desired plane surface.

15. The method of claim 13, further including:

changing an operating mode of the work machine to a curved mode where the location of the ground engaging tool relative to the desired surface is determined based on the sensed position of the ground engaging tool, independently of the rotational angle of the swing assembly.

16. The method of claim 13, further including displaying a representation of the position of the ground engaging tool relative to the desired surface configuration.

17. The method of claim 13, further including automatically moving the work implement linkage and the ground engaging tool to remove material to obtain the desired surface configuration.

18. A positioning system for a work machine having a ground engaging tool mounted on a work implement linkage and a swing assembly rotatably mounting the work implement linkage, comprising:

a control mechanism configured to control the movement of the work implement linkage and the swing assembly to thereby control the movement of the ground engaging tool;

a position sensing system operatively connected to the work implement linkage and to the swing assembly, the position sensing system configured to provide an indication of a position of the ground engaging tool and an indication of a rotational angle of the swing assembly;

an input device configured to allow an operator to enter a desired slope angle for a desired surface plane to be excavated from a geographic location, the input device further configured to allow an operator to establish a reference angle for the swing assembly; and

a control operable to determine the location of the ground engaging tool relative to the desired surface plane based on the sensed position of the ground engaging tool and the sensed rotational angle of the swing assembly.

19. The system of claim 18, further including a display device configured to provide a display having a representation of the location of the ground engaging tool relative to the desired surface plane.

20. The system of claim 18, wherein the position sensing system includes a series of sensors operatively connected to the work implement linkage.

21. The system of claim 18, wherein the input device is further configured to allow the operator to change an operating mode of the work machine to a curved mode where the control determines the location of the ground engaging tool relative to the desired surface based on the sensed position of the ground engaging tool, independently of the rotational angle of the swing assembly.

22. The system of claim 18, wherein the reference angle is indicative of a line extending substantially perpendicularly to a border of the desired surface plane.