Method and apparatus for controlling straight line travel of a tracked machine

• US 6,445,990 B1
• Filed: 03/19/2001
• Issued: 09/03/2002
• Est. Priority Date: 03/19/2001
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Manring, Noah
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US09/811,921
• Publication Number:
  US 20020133279A1
• Time in Patent Office: 533 Days
• Field of Search: 701/50, 701/41, 180/168, 180/6.2, 180/6.7, 114/144.R
• US Class Current: 701/50
• CPC Class Codes: B62D 55/125 Final drives
• CPC Class Codes: E02F 9/225 Control of steering, e.g. for hydraulic motors driving the vehicle tracks steering in general B62D
• 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: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump

Abstract

A method and apparatus for controlling straight line travel of a tracked machine having a left track and a right track. The method and apparatus includes initiating a straight line travel mode of the tracked machine, determining an initial heading angle of a heading sensor located on the tracked machine, sensing a deviation in heading angle from the initial heading angle as the tracked machine travels, determining a heading angle error in response to the deviation in heading angle, and adjusting the speed of at least one of the left and right tracks to compensate for the heading angle error.

Claims

1. A method for automatically controlling straight line travel of a tracked machine having a left track and a right track, including the steps of:

initiating a straight line travel mode of the tracked machine;

determining an initial heading angle of a heading sensor located on the tracked machine;

sensing a deviation in heading angle from the initial heading angle as the tracked machine travels;

determining a heading angle error in response to the deviation in heading angle; and

adjusting the speed of at least one of the left and right tracks to compensate for the heading angle error.

2. A method, as set forth in claim 1, wherein determining an initial heading angle of a heading sensor includes the step of determining an initial heading angle of a compass, and wherein sensing a deviation in heading angle includes the step of sensing a deviation in the heading angle of the compass.

3. A method, as set forth in claim 1, wherein initiating a straight line travel mode of the tracked machine includes the step of setting a steering control mechanism to a neutral position.

4. A method, as set forth in claim 3, further including the step of ending the straight line travel mode of the tracked machine in response to the steering control mechanism being moved out of the neutral position.

5. An apparatus for automatically controlling straight line travel of a tracked machine having a left track and a right track, comprising:

means for initiating a straight line travel mode of the tracked machine;

means for determining an initial heading angle of a heading sensor located on the tracked machine;

means for sensing a deviation in heading angle from the initial heading angle as the tracked machine travels;

means for determining a heading angle error in response to the deviation in heading angle; and

means for adjusting the speed of at least one of the left and right tracks to compensate for the heading angle error.

6. An apparatus, as set forth in claim 5, wherein the heading sensor includes a compass.

7. An apparatus, as set forth in claim 5, wherein the means for initiating a straight line travel mode of the tracked machine includes a steering control mechanism being set to a neutral position.

8. An apparatus, as set forth in claim 7, further including means for ending the straight line travel mode of the tracked machine.

9. An apparatus, as set forth in claim 8, wherein the means for ending the straight line travel mode of the tracked machine includes the steering control mechanism being moved out of the neutral position.

10. An apparatus for automatically controlling straight line travel of a tracked machine having a left track and a right track, comprising:

a steering control mechanism located on the tracked machine for initiating a straight line travel mode in response to being set to a neutral position;

a heading sensor located on the tracked machine for determining an initial heading angle of the tracked machine in response to initiation of the straight line travel mode, and for determining a deviation in heading angle from the initial heading angle as the tracked machine travels; and

a controller located on the tracked machine for determining a heading angle error in response to the deviation in heading angle, and for adjusting the speed of at least one of the left and right tracks to compensate for the heading angle error.

11. An apparatus, as set forth in claim 10, wherein the heading sensor includes a compass.

12. An apparatus, as set forth in claim 10, wherein the steering control mechanism is further adapted to end the straight line travel mode of the tracked machine in response to the steering control mechanism being moved out of the neutral position.

13. A method for automatically controlling straight line travel of a tracked machine having a left track and a right track, including the steps of:

initiating a straight line travel mode of the tracked machine in response to setting a steering control mechanism to a neutral position;

determining an initial heading angle of a compass located on the tracked machine;

sensing a deviation in heading angle from the initial heading angle as the tracked machine travels;

determining a heading angle error in response to the deviation in heading angle;

adjusting the speed of at least one of the left and right tracks to compensate for the heading angle error; and

ending the straight line travel mode of the tracked machine in response to the steering control mechanism being moved out of the neutral position.

14. An apparatus for automatically controlling straight line travel of a tracked machine having a left track and a right track, comprising:

a steering control mechanism located on the tracked machine for initiating a straight line travel mode in response to being set to a neutral position, and for ending the straight line travel mode of the tracked machine in response to the steering control mechanism being moved out of the neutral position;

a compass located on the tracked machine for determining an initial heading angle of the tracked machine in response to initiation of the straight line travel mode, and for determining a deviation in heading angle from the initial heading angle as the tracked machine travels; and

a controller located on the tracked machine for determining a heading angle error in response to the deviation in heading angle, and for adjusting the speed of at least one of the left and right tracks to compensate for the heading angle error.