Excavating implement heading control

• US 9,976,279 B2
• Filed: 08/10/2016
• Issued: 05/22/2018
• Est. Priority Date: 02/02/2016
• Status: Active Grant

• Current Assignee: Caterpillar Trimble Control Technologies LLC
• Original Assignee: Caterpillar Trimble Control Technologies LLC
• Inventors: Padilla, Christopher A.
• Primary Examiner(s): Hilgendorf, Dale W
• Application Number:
  US15/233,236
• Publication Number:
  US 20170218594A1
• Time in Patent Office: 650 Days
• CPC Class Codes: E02F 3/30 with a dipper-arm pivoted on a cantilever beam , i.e. boom
• CPC Class Codes: E02F 3/3677 allowing movement, e.g. rotation or translation, of the tool around or along another axis as the movement implied by the boom or arms, e.g. for tilting buckets
• CPC Class Codes: E02F 3/3681 Rotators
• CPC Class Codes: E02F 3/43 Control of dipper or bucket position; Control of sequence of drive operations
• CPC Class Codes: E02F 3/431 for bucket-arms, front-end loaders, dumpers or the like
• CPC Class Codes: E02F 3/435 for dipper-arms, backhoes or the like
• CPC Class Codes: E02F 3/436 for keeping the dipper in the horizontal position, e.g. self-levelling
• CPC Class Codes: E02F 3/437 providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
• CPC Class Codes: E02F 3/439 Automatic repositioning of the implement, e.g. automatic dumping, auto-return E02F3/438 takes precedence
• 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 9/2037 Coordinating the movements of the implement and of the frame
• CPC Class Codes: E02F 9/2041 Automatic repositioning of implements, i.e. memorising determined positions of the implement for dipper-arms or bucket-arms E02F3/434, E02F3/437, E02F3/438, E02F3/439 take precedence
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: E02F 9/265 with follow-up actions (e.g. control signals sent to actuate the work tool)

Abstract

An excavator comprises a chassis, an implement, and an assembly comprising a boom, a stick, and a coupling. The assembly is configured to define a heading {circumflex over (N)} and to swing with, or relative to, the chassis about a swing axis S. The stick is configured to curl relative to the boom about a curl axis C. The implement is coupled to a stick terminal point G via the coupling and is configured to rotate about a rotary axis R such that a leading edge of the implement defines a heading Î. An excavator control architecture comprises sensors and machine readable instructions to generate signals representative of {circumflex over (N)}, an assembly swing rate ω_S about S, and a stick curl rate ω_C about C, generate a signal representing a terminal point heading Ĝ based on {circumflex over (N)}, ω_S, and ω_C, and rotate the implement about R such that Î approximates Ĝ.

Claims

1. An excavator comprising a machine chassis, an excavating linkage assembly, a rotary excavating implement, and control architecture, wherein:

the excavating linkage assembly comprises an excavator boom, an excavator stick, and an implement coupling;

the excavating linkage assembly is configured to define a linkage assembly heading ({circumflex over (N)}) and to swing with, or relative to, the machine chassis about a swing axis (S) of the excavator;

the excavator stick is configured to curl relative to the excavator boom about a curl axis (C) of the excavator;

the rotary excavating implement is mechanically coupled to a terminal point (G) of the excavator stick via the implement coupling and is configured to rotate about a rotary axis (R) such that a leading edge of the rotary excavating implement defines an implement heading (Î

); and

the control architecture comprises one or more dynamic sensors, one or more linkage assembly actuators, and one or more controllers programmed to execute machine readable instructions to

generate signals that are representative of the linkage assembly heading ({circumflex over (N)}), a swing rate (ω

_S) of the excavating linkage assembly about the swing axis (S), and a curl rate (ω

_C) of the excavator stick about the curl axis (C),

generate a signal representing a directional heading (Ĝ

) of the terminal point (G) of the excavator stick based on the linkage assembly heading ({circumflex over (N)}), the swing rate (ω

_S) of the excavating linkage assembly, and the curl rate (ω

_C) of the excavator stick, and

rotate the rotary excavating implement about the rotary axis (R) such that the implement heading (Î

) approximates the directional heading (Ĝ

).

2. The excavator as claimed in claim 1 wherein:

the implement heading (Î

) defines an implement heading angle (θ

_I) measured between a heading vector of the rotary excavating implement and a reference plane (P) that is perpendicular to the curl axis (C);

the directional heading ({tilde over (G)}) defines a grade heading angle (θ

_G) measured between the directional heading ({tilde over (G)}) of the terminal point (G) of the excavator stick and the reference plane (P); and

the control architecture executes machine readable instructions to rotate the rotary excavating implement about the rotary axis (R) such that θ

_I=θ

_G.

3. The excavator as claimed in claim 2 wherein the implement heading angle (θ

_I) is approximately 0°

when the swing rate (ω

_S) is approximately zero and the curl rate (ω

_C) is greater than zero.

4. The excavator as claimed in claim 2 wherein the implement heading angle (θ

_I) is approximately 90°

when the swing rate (ω

_S) is A greater than zero and the curl rate (ω

_C) is approximately zero.

5. The excavator as claimed in claim 2 wherein the implement heading angle (θ

_I) is substantially less than 45°

when the curl rate (ω

_C) is substantially greater than the swing rate (ω

_S).

6. The excavator as claimed in claim 2 wherein the implement heading angle (θ

_I) is substantially greater than 45°

when the swing rate (ω

_S) is substantially greater than the curl rate (ω

_C).

7. The excavator as claimed in claim 2 wherein the implement heading angle (θ

_I) is approximately 45°

when the swing rate (ω

_S) is approximately equivalent to the curl rate (ω

_C).

8. The excavator as claimed in claim 1 wherein the one or more controllers are programmed to execute machine readable instructions to:

regenerate the directional heading (Ĝ

) when there is a variation in the swing rate (ω

_S), the curl rate (ω

_C), or both; and

adjust the rotation of the rotary excavating implement such that the implement heading (Î

) approximates the regenerated directional heading ({tilde over (G)}).

9. The excavator as claimed in claim 1 wherein the control architecture comprises a heading sensor, a swing rate sensor, and a curl rate sensor configured to generate the linkage assembly heading ({circumflex over (N)}), the swing rate (ω

_S), and the curl rate (ω

_C), respectively.

10. The excavator as claimed in claim 1 wherein the control architecture comprises a non-transitory computer-readable storage medium comprising the machine readable instructions.

11. The excavator as claimed in claim 1 wherein the one or more linkage assembly actuators facilitate movement of the excavating linkage assembly.

12. The excavator as claimed in claim 11 wherein the one or more linkage assembly actuators comprise a hydraulic cylinder actuator, a pneumatic cylinder actuator, an electrical actuator, a mechanical actuator, or combinations thereof.

13. The excavator as claimed in claim 1 wherein the one or more dynamic sensors comprise a global navigation satellite system (GNSS) receiver, a Universal Total Station (UTS) and machine target, an inertial measurement unit (IMU), an inclinometer, an accelerometer, a gyroscope, an angular rate sensor, a rotary position sensor, a position sensing cylinder, or combinations thereof.

14. The excavator as claimed in claim 1 wherein:

the one or more dynamic sensors comprise a heading sensor configured to generate the linkage assembly heading ({circumflex over (N)}), the directional heading (Ĝ

) of the terminal point (G), or both; and

the heading sensor comprises a global navigation satellite system (GNSS) receiver, a Universal Total Station (UTS) and machine target, an inertial measurement unit (IMU), an inclinometer, an accelerometer, a gyroscope, a magnetic compass, or combinations thereof.

15. The excavator as claimed in claim 1 wherein:

the one or more dynamic sensors comprise a swing rate sensor mounted to a swinging portion of the machine chassis, the excavating linkage assembly, or both, to generate the swing rate (ω

_S); and

the swing rate sensor comprises a global navigation satellite system (GNSS) receiver, a Universal Total Station (UTS) and machine target, an inertial measurement unit (IMU), an inclinometer, an accelerometer, a gyroscope, an angular rate sensor, a gravity based angle sensor, an incremental encoder, or combinations thereof.

16. The excavator as claimed in claim 1 wherein:

the one or more dynamic sensors comprise a curl rate sensor mounted to a curling portion of the excavating linkage assembly to generate the curl rate (ω

_C); and

the curl rate sensor comprises an inertial measurement unit (IMU), an inclinometer, an accelerometer, a gyroscope, an angular rate sensor, a gravity based angle sensor, an incremental encoder, or combinations thereof.

17. The excavator as claimed in claim 1 wherein the one or more dynamic sensors comprise a rotation angle sensor configured to generate a signal representing a rotation angle of the rotary excavating implement.

18. The excavator as claimed in claim 17 wherein the one or more dynamic sensors are configured to calculate the angles and positions of at least two pieces of equipment of:

the excavator boom, the excavator stick, the implement coupling, and a tip of the rotary excavating implement, wherein angles and positions of the at least two pieces of equipment are calculated with respect to one another, or each piece of equipment with respect to a benched reference point for each piece of equipment, or both.

19. The excavator as claimed in claim 1 wherein:

the implement coupling comprises a tilt-rotator attachment that is structurally configured to enable rotation and tilt of the rotary excavating implement;

the one or more dynamic sensors comprise a tilt angle sensor configured to generate a signal representing a tilt angle of the rotary excavating implement; and

the control architecture comprises a grade control system responsive to signals generated by the one or more dynamic sensors and is configured to execute machine readable instructions to control the tilt angle of the rotary excavating implement via the tilt-rotator attachment to follow a design of a slope for a final graded surface stored in the grade control system.

20. The excavator as claimed in claim 1 wherein:

the rotary axis (R) is defined by the implement coupling joining the excavator stick and the rotary excavating implement.

21. The excavator as claimed in claim 1 wherein:

the excavating linkage assembly comprises a stick coupling joining the excavator boom and the excavator stick; and

the rotary axis (R) is defined by the stick coupling joining the excavator boom and the excavator stick.

22. A method of automating tilt and rotation of a rotary excavating implement of an excavator, the method comprising:

providing an excavator comprising a machine chassis, an excavating linkage assembly, a rotary excavating implement, and control architecture comprising one or more dynamic sensors, one or more linkage assembly actuators, and one or more controllers, wherein;

the excavating linkage assembly comprises an excavator boom, an excavator stick, and an implement coupling;

the excavating linkage assembly is configured to define a linkage assembly heading ({circumflex over (N)}) and to swing with, or relative to, the machine chassis about a swing axis (S) of the excavator;

the excavator stick is configured to curl relative to the excavator boom about a curl axis (C) of the excavator;

the rotary excavating implement is mechanically coupled to a terminal point (G) of the excavator stick via the implement coupling and is configured to rotate about a rotary axis (R) such that a leading edge of the rotary excavating implement defines an implement heading (Î

); and

generating, by the one or more dynamic sensors, the one or more controllers, or both, signals that are representative of the linkage assembly heading ({circumflex over (N)}), a swing rate (ω

_S) of the excavating linkage assembly about the swing axis (S), and a curl rate (ω

_C) of the excavator stick about the curl axis (C),

generating, by the one or more dynamic sensors, the one or more controllers, or both, a signal representing a directional heading (Ĝ

) of the terminal point (G) of the excavator stick based on the linkage assembly heading ({circumflex over (N)}), the swing rate (ω

_S) of the excavating linkage assembly, and the curl rate (ω

_C) of the excavator stick, and

rotating, by the one or more controllers and the one or more linkage assembly actuators, the rotary excavating implement about the rotary axis (R) such that the implement heading (Î

) approximates the directional heading (Ĝ

).