Payload Estimation system

• US 8,909,437 B2
• Filed: 10/17/2012
• Issued: 12/09/2014
• Est. Priority Date: 10/17/2012
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Zhu, Yongliang, Faivre, Joseph, Fehr, Drew A.
• Primary Examiner(s): Cheung, Mary
• Assistant Examiner(s): Trivedi, Atul
• Application Number:
  US13/654,028
• Publication Number:
  US 20140107897A1
• Time in Patent Office: 783 Days
• Field of Search: 701/50, 701 53- 54, 701/84, 701/87, 701/90, 701/124, 172 75- 76
• US Class Current: 701/50
• CPC Class Codes: E02F 3/435 for dipper-arms, backhoes or the like
• CPC Class Codes: E02F 9/00 Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00 laying-out or take-up devices for trailing electric cables B66C
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: G01G 23/01 Testing or calibrating of weighing apparatus
• CPC Class Codes: G05B 2219/45012 Excavator

Abstract

A payload control system includes a sensor system and a force sensor system. A controller determines a calibration machine state, a calibration linkage force, and machine calibration parameters based at least in part upon the calibration machine state and the calibration linkage force. The controller also determines a loaded implement machine state, a loaded implement linkage force, and a mass of the payload based at least in part upon the machine calibration parameters, the loaded implement machine state, and the loaded implement linkage force.

Claims

1. A system for determining a mass of a payload moved by a work implement, comprising:

a linkage member being movable along a path, the linkage member being operatively connected to move the work implement;

a sensor system configured to provide a plurality of machine state signals indicative of a state of a machine;

a force sensor system configured to provide a linkage force signal indicative of a force on the linkage member; and

a controller configured to;

receive a first set of unloaded machine state signals as the work implement is moved in an unloaded condition;

determine a calibration machine state based upon the first set of unloaded machine state signals and without moving the work implement in a loaded state;

determine a calibration linkage force on the linkage member based at least in part upon a calibration linkage force signal generated as the work implement is moved in the unloaded condition and without input based upon moving the work implement in a loaded state;

determine machine calibration parameters based at least in part upon the calibration machine state and the calibration linkage force and without input based upon moving the work implement in a loaded state;

receive a second set of loaded machine state signals as the work implement is moved in a loaded condition;

determine a loaded implement machine state based upon the second set of loaded machine state signals;

determine a loaded implement linkage force on the linkage member based at least in part upon a loaded implement linkage force signal generated as the work implement is moved in the loaded condition; and

determine a mass of the payload based at least in part upon the machine calibration parameters, the loaded implement machine state, and the loaded implement linkage force.

2. The system of claim 1, wherein the controller is further configured to receive the unloaded implement machine state signals while the work implement is moved along a three-dimensional path.

3. The system of claim 1, wherein the controller is further configured to determine a calibration torque at a pivot joint of the linkage member based at least in part upon the calibration linkage force and without input based upon moving the work implement in a loaded state, and determine the machine calibration parameters based at least in part upon the calibration torque.

4. The system of claim 3, wherein the controller is further configured to determine a loaded implement torque at the pivot joint of the linkage member based at least in part upon the loaded implement linkage force, and determine the mass of the payload based at least in part upon the loaded implement torque.

5. The system of claim 1, wherein the system further includes an actuator operatively connected to the linkage member.

6. The system of claim 1, wherein the system further includes a swing member and an implement system comprising the linkage member, the implement system including a boom member, a stick member, and the work implement.

7. The system of claim 6, wherein the machine state signals include an angular position of at least one of the swing member, the boom member, the stick member, and the work implement.

8. The system of claim 6, wherein the machine state signals include an angular velocity of at least one of the swing member, the boom member, the stick member, and the work implement.

9. The system of claim 6, wherein the machine state signals include an angular acceleration of at least one of the swing member, the boom member, the stick member, and the work implement.

10. The system of claim 6, wherein the machine state signals include at least one of a pitch and a roll of the machine.

11. The system of claim 6, wherein the machine calibration parameters are based at least in part upon an inertia of one of the boom member, the stick member, and the work implement.

12. The system of claim 6, wherein the machine calibration parameters are based at least in part upon a mass of one of the boom member, the stick member, and the work implement.

13. The system of claim 6, wherein the machine calibration parameters are based at least in part upon a distance of a center of gravity of one of the boom member, the stick member, and the work implement from its pivot joint and an angle of the center of gravity relative to the pivot joint.

14. A controller implemented method of determining a mass of a payload moved by a work implement, comprising:

receiving a first set of unloaded machine state signals as a work implement is moved in an unloaded condition;

determining a calibration machine state based upon the first set of unloaded machine state signals and without moving the work implement in a loaded state;

determining a calibration linkage force on a linkage member based at least in part upon a calibration linkage force signal generated as the work implement is moved in the unloaded condition and without input based upon moving the work implement in a loaded state;

determining machine calibration parameters based at least in part upon the calibration machine state and the calibration linkage force and without input based upon moving the work implement in a loaded state;

receiving a second set of loaded machine state signals as the work implement is moved in a loaded condition;

determining a loaded implement machine state based upon the second set of loaded machine state signals;

determining a loaded implement linkage force on the linkage member based at least in part upon a loaded implement linkage force signal generated as the work implement is moved in the loaded condition; and

determining a mass of the payload based at least in part upon the machine calibration parameters, the loaded implement machine state, and the loaded implement linkage force.

15. The method of claim 14, further including moving the work implement along a three-dimensional path while receiving the first set of unloaded machine state signals.

16. The method of claim 14, further including determining a calibration torque at a pivot joint of the linkage member based at least in part upon the calibration linkage force and without input based upon moving the work implement in a loaded state, and determining the machine calibration parameters based at least in part upon the calibration torque.

17. The method of claim 16, further including determining a loaded implement torque at the pivot joint of the linkage member based at least in part upon the loaded implement linkage force, and determining the mass of the payload based at least in part upon the loaded implement torque.

18. The method of claim 14, further including providing a swing member and an implement system including a boom member, a stick member, and the work implement, and further including positioning the implement system in different manners while the work implement is moved in an unloaded condition along a three-dimensional path.

19. The method of claim 18, further including repeating movements of the work implement in an unloaded condition a predetermined number of times.

20. A machine comprising:

a work implement;

a linkage member being movable along a path, the linkage member being operatively connected to move the work implement;

a sensor system configured to provide a plurality of machine state signals indicative of a state of the machine;

a force sensor system configured to provide a linkage force signal indicative of a force on the linkage member; and

a controller configured to;

receive a first set of unloaded machine state signals as the work implement is moved in an unloaded condition;

determine a calibration machine state based upon the first set of machine state signals and without moving the work implement in a loaded state;

determine a calibration linkage force on the linkage member based at least in part upon a calibration linkage force signal generated as the work implement is moved in the unloaded condition and without input based upon moving the work implement in a loaded state;

determine machine calibration parameters based at least in part upon the calibration machine state and the calibration linkage force and without input based upon moving the work implement in a loaded state;

receive a second set of machine state signals as the work implement is moved in a loaded condition;

determine a loaded implement machine state based upon the second set of machine state signals;

determine a loaded implement linkage force on the linkage member based at least in part upon a loaded implement linkage force signal generated as the work implement is moved in the loaded condition; and

determine a mass of the payload based at least in part upon the machine calibration parameters, the loaded implement machine state, and the loaded implement linkage force.

21. A controller implemented method of determining machine calibration parameters of a machine, the machine having a swing member and an implement system including a boom member, a stick member, and a work implement, comprising:

rotating the swing member relative to a frame member while moving the boom member vertically with the work implement in an unloaded condition;

receiving a set of unloaded machine state signals as the swing member is rotated and the boom member is moved vertically with the work implement in the unloaded condition;

determining a calibration machine state based upon the set of unloaded machine state signals;

determining a calibration linkage force on a linkage member based upon a calibration linkage force signal generated as the work implement is moved in the unloaded condition; and

determining machine calibration parameters based upon the calibration machine state and the calibration linkage force.

22. The method of claim 21, further including moving the stick member relative to the boom member while rotating the swing member and moving the boom member.