Excavating implement heading control

Patent metadata

Field	Value
Publication number	US-9976279-B2
Application number	US-201615233236-A
Country	US
Kind code	B2
Filing date	Aug 10, 2016
Priority date	Feb 2, 2016
Publication date	May 22, 2018
Grant date	May 22, 2018

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.

First claim

What is claimed is:

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 rotar

Assignees

• Caterpillar Trimble Control Tech Llc

Inventors

• Padilla Christopher A

Classifications

• E02F3/43

  Control of dipper or bucket position; Control of sequence of drive operations · CPC title

• E02F3/431

  for bucket-arms, front-end loaders, dumpers or the like · CPC title

• E02F9/264

  Sensors and their calibration for indicating the position of the work tool · CPC title

• E02F9/2041

  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 title

• E02F3/437

  providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant · CPC title