System for controlling implement position

• US 7,725,234 B2
• Filed: 07/31/2006
• Issued: 05/25/2010
• Est. Priority Date: 07/31/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Shull, Andrew G.
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): Figueroa; Jaime
• Application Number:
  US11/495,484
• Publication Number:
  US 20080027610A1
• Time in Patent Office: 1,394 Days
• Field of Search: 701 50- 66, 701/82, 172 2- 5, 172 9- 10, 374/14
• US Class Current: 701/50
• CPC Class Codes: A01B 63/1117 using a hitch position sensor

Abstract

A system for controlling implement position including a method for controlling movement of an implement is disclosed. The method includes determining a first parameter configured to affect control of the implement with respect to a first timing. The method also includes determining a second parameter configured to affect control of the implement with respect to a second timing. The second timing is shorter than the first timing. The method also includes selectively establishing a third parameter as a function of the first and second parameters when the second parameter is greater than a predetermined value. The method further includes controlling a position of the implement as a function of the third parameter.

Claims

1. A method for controlling a working depth position of an implement of a machine, comprising:

determining slip of a traction device;

determining a change in draft force of the implement over a period of time; and

selectively controlling the working depth position of the implement as a function of slip and the change in draft force.

2. The method of claim 1, further including:

selectively controlling a working depth position of the implement as a function of slip and not as a function of the chance in draft force when the change in draft force is less than a predetermined value.

3. The method of claim 1, wherein the implement is operably connected to a machine having at least one traction device, the method further including:

sensing a first speed indicative of a driven component of the at least one traction device;

sensing a second speed indicative of the machine with respect to a surface, the machine configured to move relative to the surface; and

determining slip as a function of the first and second speeds.

4. The method of claim 1, wherein the implement is operably connected to a machine via at least one hydraulic actuator, the method further including:

sensing a pressure of a fluid operably associated with the at least one hydraulic actuator at two different times; and

determining the change in draft force as a function of the change in pressure sensed at the two different times.

5. The method of claim 1, wherein

the amount of slip is indicative of a percentage difference between a driven speed and an actual speed.

6. A system for controlling an implement'"'"'s working depth, comprising:

at least one hydraulic actuator operatively configured to move the implement with respect to a frame of a machine;

a traction device operatively connected to the frame and configured to propel the machine relative to a surface of a material;

a first sensor configured to sense a pressure of fluid associated with the at least one hydraulic actuator;

a second sensor configured to sense a speed of a driven component of the traction device;

a third sensor configured to sense a speed of the machine with respect to the surface; and

a controller configured to;

receive a plurality of signals indicative of the sensed pressure, the speed of the driven component, and the speed of the machine,

determine slip of the traction device as a function of the speed of the driven component and the speed of the machine,

determine a change in draft force of the implement as a function of a change in the sensed pressure measured over a time period, and

determine an output command configured to affect the working depth position of the implement as a function of the slip and the change in draft force.

7. The system of claim 6, wherein the controller is further configured to

determine if the change in pressure is greater than a predetermined value.

8. The system of claim 7, wherein determining the output command includes selectively adding an output command associated with the change in draft force to an output command associated with slip only when the change in pressure is greater than the predetermined value.

9. The system of claim 6, wherein determining the output command includes selectively adding an output command associated with the chance in draft force to an output command associated with slip.

10. A machine comprising:

at least one traction device having a driven component;

an implement configured to selectively engage a material;

a first sensor configured to sense a speed of the driven component with respect to the machine and responsively generate a first signal;

a second sensor configured to sense a speed of the machine with respect to a surface of material and responsively generate a second signal;

a third sensor configured to sense a pressure of fluid used to affect movement of the implement and responsively generate a third signal;

a controller configured to;

receive the first, second, and third signals,

determine slip as a function of the first and second signals,

determine a change in draft force acting on the implement over a period of time based on the third signal,

affect a working depth position of the implement as a function of only slip when the change in draft force is below a predetermined value, and

affect a working depth position of the implement as a function of slip and the change in draft force when the change in draft force is above the predetermined value.

11. The machine of claim 10, wherein the controller is configured to affect the working depth of the implement by selectively raising and lowering the implement within a work surface.

12. The machine of claim 10, wherein:

the controller is further configured to determine the change in draft force as a function of a change of the third signal during the period of time.