Patent US5446980A successfully refreshed from Google Patents.
US5446980A
Expired / Lapsed
US
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Automatic excavation control system and method
Assignee: Caterpillar Inc
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Filing: 1994-03-23
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Granted: 1995-09-05
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Expires: 2014-03-23
Abstract
Abstract A control system automatically controls a work implement of an excavating machine through a machine work cycle. The work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder. A position sensor produces respective position signals in response to the respective position of the boom, stick and bucket. A microprocessor receives the position signals, compares at least one of the boom, stick and bucket position signals to a predetermined one of a plurality of position setpoints. A pressure sensor produces respective pressure signals in response to the associated hydraulic pressures associated with the boom, stick, and bucket hydraulic cylinders. The microprocessor receives the pressure signals, and compares at least one of the boom, stick and bucket pressures to a predetermined one of a plurality of pressure setpoints. An operator interface produces a material condition setting, the material condition setting being representative of a predetermined condition of the excavating soil. The logic device produces a command signal in response to the pressure and position comparisons, the command signal having a magnitude responsive to the material condition setting. An electrohydraulic system receives the command signal and controllably actuates predetermined ones of the hydraulic cylinders to perform the work cycle.
Inventors
- 👤 David J. Rocke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:52
CPC Classifications
E; E02; E02F; E02F3/00; E02F3/04; E02F3/28; E02F3/36; E02F3/42; E02F3/43; E02F3/435; E02F3/439
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
217 words
A control system for automatically controlling a work implement of an excavating machine through a machine work cycle, the work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder, the hydraulic cylinders containing pressurized hydraulic fluid, the control system comprising: position sensing means for producing respective position signals in response to the respective position of the boom, stick and bucket; means for receiving the position signals, comparing at least one of the boom, stick and bucket position signals to a predetermined one of a plurality of position setpoints; pressure sensing means for producing respective pressure signals in response to the associated hydraulic pressures associated with the boom, stick, and bucket hydraulic cylinders; means for receiving the pressure signals, comparing at least one of the boom, stick and bucket pressures to a predetermined one of a plurality of pressure setpoints; means for producing a material condition setting, the material condition setting being representative of a predetermined condition of the excavating soil; means for producing a command signal in response to the pressure and position comparisons, the command signal having a magnitude responsive to the material condition setting; and actuating means for receiving the command signal and controllably actuating predetermined ones of the hydraulic cylinders to perform the work cycle.
Claim 2
Dependent Claim
217 words
A control system for automatically controlling a work implement of an excavating machine through a machine work cycle, the work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder, the hydraulic cylinders containing pressurized hydraulic fluid, the control system comprising: position sensing means for producing respective position signals in response to the respective position of the boom, stick and bucket; means for receiving the position signals, comparing at least one of the boom, stick and bucket position signals to a predetermined one of a plurality of position setpoints; pressure sensing means for producing respective pressure signals in response to the associated hydraulic pressures associated with the boom, stick, and bucket hydraulic cylinders; means for receiving the pressure signals, comparing at least one of the boom, stick and bucket pressures to a predetermined one of a plurality of pressure setpoints; means for producing a material condition setting, the material condition setting being representative of a predetermined condition of the excavating soil; means for producing a command signal in response to the pressure and position comparisons, the command signal having a magnitude responsive to the material condition setting; and actuating means for receiving the command signal and controllably actuating predetermined ones of the hydraulic cylinders to perform the work cycle.
Claim 3
Dependent Claim
48 words
A control system, as set forth in claim 1, including a memory means for storing a plurality of command signal magnitudes associated with each hydraulic cylinder, the command signal magnitudes being represented by at least one control curve that is responsive to at least one material condition setting.
Claim 4
Dependent Claim
128 words
A control system, as set forth in claim 2, including: a swing assembly adapted to rotate the work implement; boom-down means for producing boom command signals to lower the boom; pre-dig means for producing boom, stick, and bucket command signals to position the bucket to a predetermined cutting angle; dig-stroke means for producing boom, stick, and bucket command signals to move the bucket along the ground; capture-load means for producing boom, stick, and bucket command signals capture material in the bucket; dump-load means for producing boom, stick, bucket, and swing command signals to dump the material from the bucket to a desired dump location; and return-to-dig means for producing boom, stick, and swing command signals to move the work implement from the dump location to a dig location.
Claim 5
Dependent Claim
73 words
A control system, as set forth in claim 3, wherein the memory means includes means for storing a plurality of control curves representing a plurality of command signal magnitudes associated with the boom cylinder, each control curve corresponding to a predetermined material condition setting, the pre-dig means selecting a predetermined control curve in response to the material condition setting and producing a command signal having a magnitude dictated by the bucket cylinder pressure.
Claim 6
Dependent Claim
61 words
A control system, as set forth in claim 4, wherein the memory means includes means for storing a single control curve representing a plurality of command signal magnitudes associated with the stick cylinder, the control curve representing the full range of the material condition settings, the pre-dig means producing a command signal having a magnitude dictated by the stick cylinder pressure.
Claim 7
Dependent Claim
73 words
A control system, as set forth in claim 5, wherein the memory means includes means for storing a plurality of control curves representing a plurality of command signal magnitudes associated with the boom cylinder, each control curve corresponding to a predetermined material condition setting, the dig-stroke means selecting a predetermined control curve in response to the material condition setting and producing a command signal having a magnitude dictated by the stick cylinder pressure.
Claim 8
Dependent Claim
73 words
A control system, as set forth in claim 6, wherein the memory means includes means for storing a plurality of control curves representing a plurality of command signal magnitudes associated with the bucket cylinder, each control curve corresponding to a predetermined material condition setting, the dig-stroke means selecting a predetermined control curve in response to the material condition setting and producing a command signal having a magnitude dictated by the bucket cylinder pressure.
Claim 9
Dependent Claim
61 words
A control system, as set forth in claim 1, including means for receiving the pressure signals and responsively computing a correlative force signal for each of the boom, stick and bucket hydraulic cylinders and comparing each of the correlative force signals with a plurality of predetermined force setpoints, wherein the command signal is produced in response to the force signal comparison.
Claim 10
Dependent Claim
24 words
A control system, as set forth in claim 1, wherein predetermined ones of the position set points are responsive to the material condition setting.
Claim 11
Dependent Claim
35 words
A control system, as set forth in claim 1, including means for determining the penetration of the bucket into the ground, and modifying predetermined ones of the position setpoints in response to the bucket penetration.
Claim 12
Dependent Claim
19 words
A control system, as set forth in claim 1, wherein the material condition setting means includes an operator interface.
Claim 13
Dependent Claim
28 words
A control system, as set forth in claim 11, wherein the operator interface provides for the operator to select predetermined settings representative of material hardness and material moisture.
Claim 14
Independent Claim
194 words
A method for automatically controlling a work implement of an excavating machine through a machine work cycle, the work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder, the hydraulic cylinders containing pressurized hydraulic fluid, including the steps of: producing respective position signals in response to the respective position of the boom, stick and bucket; receiving the position signals, comparing at least one of the boom, stick and bucket position signals to a predetermined one of a plurality of position setpoints; producing respective force signals in response to the force in the boom, stick, and bucket hydraulic cylinders; receiving the force signals, comparing at least one of the boom, stick and bucket forces to a predetermined one of a plurality of force setpoints; producing a material condition setting, the material condition setting being representative of a predetermined condition of the excavating soil; producing a command signal in response to the force and position comparisons, the command signal having a magnitude responsive to the material condition setting; and receiving the command signal and controllably actuating predetermined ones of the hydraulic cylinders to perform the work cycle.
Claim 15
Independent Claim
194 words
A method for automatically controlling a work implement of an excavating machine through a machine work cycle, the work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder, the hydraulic cylinders containing pressurized hydraulic fluid, including the steps of: producing respective position signals in response to the respective position of the boom, stick and bucket; receiving the position signals, comparing at least one of the boom, stick and bucket position signals to a predetermined one of a plurality of position setpoints; producing respective force signals in response to the force in the boom, stick, and bucket hydraulic cylinders; receiving the force signals, comparing at least one of the boom, stick and bucket forces to a predetermined one of a plurality of force setpoints; producing a material condition setting, the material condition setting being representative of a predetermined condition of the excavating soil; producing a command signal in response to the force and position comparisons, the command signal having a magnitude responsive to the material condition setting; and receiving the command signal and controllably actuating predetermined ones of the hydraulic cylinders to perform the work cycle.
Claim 16
Dependent Claim
46 words
A method, as set forth in claim 13, including the step of storing a plurality of command signal magnitudes associated with each hydraulic cylinder, the command signal magnitudes being represented by at least one control curve that is responsive to at least one material condition setting.
Claim 17
Dependent Claim
32 words
A method, as set forth in claim 14, wherein the step of producing the force signal includes the step of sensing the respective pressure in the boom, stick, and bucket hydraulic cylinders.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-09-04 | 1999-03-06 | 1999-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-09-04 | 2003-03-06 | 2003-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-09-04 | 2007-03-06 | 2007-09-05 | $7700.00 | Window Closed / Lapsed |