U.S. patent application number 11/214993 was filed with the patent office on 2007-03-01 for system for controlling an earthworking implement.
This patent application is currently assigned to Caterpillar Inc.. Invention is credited to Scott E. Bailey, Kenneth L. Stratton.
Application Number | 20070044980 11/214993 |
Document ID | / |
Family ID | 37421170 |
Filed Date | 2007-03-01 |
United States Patent
Application |
20070044980 |
Kind Code |
A1 |
Stratton; Kenneth L. ; et
al. |
March 1, 2007 |
System for controlling an earthworking implement
Abstract
A method for controlling an earthworking implement of an
earthworking machine is disclosed. The method includes determining
a first depth of cut of the earthworking implement at least
partially based on a power capability of the earthworking
implement. The method also includes determining a second depth of
cut of the earthworking implement at least partially based on a
desired grade of a work site. The method further includes moving
the earthworking implement in response to at least one of the first
depth of cut and the second depth of cut.
Inventors: |
Stratton; Kenneth L.;
(Dunlap, IL) ; Bailey; Scott E.; (Dunlap,
IL) |
Correspondence
Address: |
CATERPILLAR/FINNEGAN, HENDERSON, L.L.P.
901 New York Avenue, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Caterpillar Inc.
|
Family ID: |
37421170 |
Appl. No.: |
11/214993 |
Filed: |
August 31, 2005 |
Current U.S.
Class: |
172/4.5 |
Current CPC
Class: |
E02F 3/844 20130101;
E02F 9/2029 20130101; E02F 3/7618 20130101 |
Class at
Publication: |
172/004.5 |
International
Class: |
E02F 3/76 20060101
E02F003/76 |
Claims
1. A method for controlling an earthworking implement of an
earthworking machine comprising: determining a first depth of cut
of the earthworking implement at least partially based on a power
capability of the earthworking implement; determining a second
depth of cut of the earthworking implement at least partially based
on a desired grade of a work site; and moving the earthworking
implement in response to at least one of the first depth of cut and
the second depth of cut.
2. The method of claim 1, further including moving the earthworking
implement to the determined first depth of cut when the magnitude
of the determined first depth of cut is less than the magnitude of
the determined second depth of cut.
3. The method of claim 1, further including moving the earthworking
implement to the determined second depth of cut when the magnitude
of the determined second depth of cut is less than the magnitude of
the determined first depth of cut.
4. The method of claim 1, wherein moving the earthworking implement
includes selectively moving the earthworking implement to the one
of the determined first depth of cut and the determined second
depth of cut having a smaller magnitude and subsequently
selectively moving the earthworking implement to the other of the
determined first depth of cut and the determined second depth of
cut.
5. The method of claim 1, further including producing a first depth
of cut signal at least partially based on the determined first
depth of cut; producing a second depth of cut signal at least
partially based on the determined second depth of cut; and
monitoring the first depth of cut signal and the second depth of
cut signal.
6. The method of claim 5, further including: producing a command
signal at least partially based on one of the first depth of cut
signal and the second depth of cut signal; and moving the
earthworking implement in response to the command signal.
7. The method of claim 5, wherein: producing the first depth of cut
signal includes determining a desired productive depth of cut,
determining an actual depth of cut of the earthworking implement,
and determining a difference between the desired productive depth
of cut and the actual depth of cut of the earthworking
implement.
8. The method of claim 7, further including: prohibiting the first
depth of cut signal from affecting movement of the earthworking
implement when the magnitude of the second depth of cut is less
than the magnitude of the first depth of cut.
9. The method of claim 8, wherein prohibiting the first depth of
cut signal includes selectively overriding the calculated
difference.
10. The method of claim 5, wherein: producing the second depth of
cut signal includes comparing an actual geographic model of a work
site with a desired geographic model of the work site and
determining a location of an earthworking machine and the
earthworking implement with respect to the actual and desired
geographic models of the work site.
11. The method of claim 10, further including: prohibiting the
second depth of cut signal from affecting movement of the
earthworking implement when the magnitude of the first depth of cut
is less than the magnitude of the second depth of cut.
12. The method of claim 11, wherein prohibiting the second depth of
cut signal includes selectively suspending the output of the second
depth of cut signal.
13. A method of moving an earthworking implement of an earthworking
machine comprising: moving the earthworking implement toward a
first depth of cut wherein the first depth of cut is at least
partially based on a desired grade; and automatically moving the
earthworking implement toward a second depth of cut wherein the
second depth of cut is different than the first depth of cut and
the second depth of cut is at least partially based on a power
capability of the earthworking implement.
14. The method of claim 13, wherein the second depth of cut is
shallower than the first depth of cut, the method further including
automatically moving the earthworking implement toward a third
depth of cut wherein the third depth of cut is at least partially
based on a desired grade.
15. The method of claim 13, wherein the second depth of cut is
shallower than the first depth of cut, the method further including
automatically moving the earthworking implement toward a third
depth of cut wherein the third depth of cut is shallower than the
second depth of cut.
16. The method of claim 13, wherein the second depth of cut is
deeper than the first depth of cut, the method further including
automatically moving the earthworking implement toward a third
depth of cut wherein the third depth of cut is shallower than the
second depth of cut.
17. The method of claim 16, wherein the third depth of cut is at
least partially based on the power capability of the earthworking
implement.
18. The method of claim 13, further including: controlling the
earthworking implement with a control system; and dynamically
outputting a command signal from the control system to
automatically move the earthworking implement to one of the first
and second depths of cut.
19. The method of claim 13, further including: moving the
earthworking implement to the first depth of cut wherein the first
depth of cut is the desired grade; and removing a first layer of
material from a work site to achieve the desired grade.
20. An earthworking machine comprising: a frame; a traction device;
a earthworking implement; a controller operably connected to the
earthworking implement and configured to compare a first depth of
cut signal indicative of a productive depth of cut and a second
depth of cut signal indicative of a contour depth of cut and
further configured to selectively move the earthworking implement
to a working depth of cut in response to at least one of the first
depth of cut signal and the second depth of cut signal.
21. The earthworking machine of claim 20, wherein the controller is
configured to selectively move the earthworking implement in
response to the first depth of cut when the magnitude of the first
depth of cut is less than the magnitude of the second depth of
cut.
22. The earthworking machine of claim 20, wherein the controller is
configured to selectively move the earthworking implement in
response to the second depth of cut when the magnitude of the
second depth of cut is less than the magnitude of the first depth
of cut.
23. The earthworking machine of claim 20, wherein determining a
productive depth of cut includes sensing one or more of the
following: the speed of the earthworking machine, the slope of a
work site in which the earthworking machine is located, the slip of
the of the traction device, and the tilt of the earthworking
implement.
24. The earthworking machine of claim 20, wherein determining a
contour depth of cut includes: comparing a desired geographic model
of a work site with an actual geographic model of a work site;
sensing the position of the earthworking machine relative to the
desired and actual geographic models of the work site; and sensing
the position of the earthworking implement relative to the
earthworking machine.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to a method and
apparatus for controlling an earthworking implement, and more
particularly, to a method and apparatus for controlling an
earthworking implement with respect to a working depth of cut.
BACKGROUND
[0002] Earthworking machines such as, for example, dozers, loaders,
excavators, motor graders, and other types of earth moving
machines, are often used to remove material from a work site to
achieve a desired work site grade. Specifically, it may be desired
to remove a layer of a first material to expose a second material
located beneath the first layer. For example, it may be desired to
remove a layer of dirt and/or rock to expose a valuable layer of
coal or other ore. Additionally, it may be desired to remove a
layer of material to achieve a desired grade to prepare a work site
for further construction. For example, it may be desired to remove
a layer of dirt and/or rock to establish a desired grade for a
parking lot or road.
[0003] Methods have been employed to control earthworking machines
and, in particular, earthworking implements during the material
removal process. For example, U.S. Pat. No. 5,819,190 ("the '190
patent") issued to Nakagami et al. discloses a control system which
monitors variables of an earthworking implement and of an
earthworking machine and responsively controls the earthworking
implement relative to material to be removed. Specifically, the
system of the '190 patent determines the operational cutting edge
position of an earthworking implement with respect to the ground
and controls the earthworking implement to be raised or lowered to
be kept coincident with a preset target cutting edge position.
[0004] Although the system of the '190 patent may automatically
control the depth of cut of an earthworking implement, the
earthworking implement may be undesirably controlled because the
system of the '190 patent may not account for depth of cut
differences between a desired contour of the work site and the
capability of the earthworking machine to remove material from the
work site. Specifically, the earthworking implement of the '190
patent may be controlled to remove material desired to remain in
the work site, thus wasting valuable material and/or requiring
material to be replaced to achieve a desired grade. Additionally,
the earthworking implement of the '190 patent may be controlled to
remove less material than desired from the work site, thus wasting
earthworking implement productivity.
[0005] The disclosed method and apparatus for controlling an
earthworking implement is directed to overcoming one or more of the
problems set forth above.
SUMMARY OF THE INVENTION
[0006] In one aspect, the present disclosure is directed to a
method for controlling an earthworking implement of an earthworking
machine. The method includes determining a first depth of cut of
the earthworking implement at least partially based on a power
capability of the earthworking implement. The method also includes
determining a second depth of cut of the earthworking implement at
least partially based on a desired grade of a work site. The method
further includes moving the earthworking implement in response to
at least one of the first depth of cut and the second depth of
cut.
[0007] In another aspect, the present disclosure is directed to a
method of moving an earthworking implement of an earthworking
machine which includes moving the earthworking implement toward a
first depth of cut. The first depth of cut being at least partially
based on a desired grade. The method also includes automatically
moving the earthworking implement toward a second depth of cut. The
second depth of cut being different than the first depth of cut and
the second depth of cut being at least partially based on a power
capability of the earthworking implement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a pictorial illustration of a exemplary disclosed
earthworking machine;
[0009] FIG. 2 is a schematic illustration of a control system of
the disclosed earthworking machine of FIG. 1; and
[0010] FIG. 3 is an exemplary block diagram of a method of the
disclosed control system of FIG. 2.
DETAILED DESCRIPTION
[0011] FIG. 1 illustrates an exemplary earthworking machine 12.
Earthworking machine 12 may be a mobile machine that performs some
type of operation associated with an industry such as mining,
construction, farming, or other industry known in the art. For
example, earthworking machine 12 may be a dozer, a loader, a
backhoe, an excavator, a motor grader, or any other earthworking
machine known in the art. Earthworking machine 12 may be configured
to traverse a work site 10 to remove material 100 from and/or add
material 100 to locations within work site 10. Earthworking machine
12 may include a frame 14, an earthworking implement 16, and a
control system 18.
[0012] Frame 14 may include any structural unit that supports
movement of earthworking machine 12. Frame 14 may be, for example,
a stationary base frame connecting a power source (not shown) to a
traction device 24, a movable frame member of a linkage system, or
any other type of frame known in the art. It is contemplated that
traction device 24 may include tracks, wheels, and/or other
traction devices known in the art.
[0013] Earthworking implement 16 may include a device used in the
performance of material handling. For example, earthworking
implement 16 may include a blade, a scraper, a bucket, a shovel,
and/or other types of earthworking implements known in the art.
Earthworking implement 16 may be coupled to frame 14 via a
hydraulic cylinder 20 and a linkage system 22 and may be
selectively movable relative to frame 14 by hydraulic cylinder 20.
Additionally, earthworking implement 16 may be moved relative to a
surface 102 of material 100 to remove material 100 from work site
10. Earthworking implement 16 may be configured to pivot, rotate,
slide, swing, or otherwise move relative to frame 14 in any manner
known in the art. It is contemplated that earthworking implement 16
may include multiple earthworking implements.
[0014] Referring to FIG. 2, control system 18 may be configured to
control the operation of earthworking machine 12 and, in
particular, configured to control earthworking implement 16.
Control system 18 may include a command controller 400, a
productive controller 402, and a contour controller 404, and may be
configured to interact with hydraulic cylinder 20 to control the
extension and/or retraction thereof to affect movement of
earthworking implement 16. Control system 18 may also be configured
to interact with auxiliary devices 50 such as, for example, a power
source, a steering apparatus, drive train apparatus, and/or other
devices used to operate earthworking machine 12 and/or components
thereof to selectively and/or dynamically affect movement thereof
over work site 10. It is contemplated that control system 18 may
additionally include other components, such as, for example,
operator interfaces, visual displays, warning indicators, sensors,
and/or other components known in the art to display, affect, and/or
control the operation of earthworking machine 12 and/or components
thereof. It is also contemplated that control system 18 may include
command controller 400, productive controller 402, and contour
controller 404 embodied as a single controller, two controllers,
and/or any number of controllers, as desired.
[0015] Productive controller 402 may be configured to determine a
productive depth of cut of earthworking implement 16 relative to
surface 102 to maximize the productive removal of material 100 from
work site 10. The productive depth of cut may be based in part on
the power capability of earthworking implement 16, which may be
based in part on the ability of earthworking implement 16 to
productively remove material 100 from work site 10. Productive
controller may be further configured to output a command signal
D.sub.P, indicative of the determined productive depth of cut, to
command controller 400 to affect the movement of earthworking
implement 16 in response to the determined productive depth of cut.
For example, if productive controller 402 determines that
earthworking implement 16 is operating at a depth of cut shallower
than an optimal productivity, e.g., earthworking implement 16 may
be unproductively removing too small an amount of material 100,
productive controller 402 may be configured to output command
signal D.sub.P to command controller 400 which would lower
earthworking implement 16 deeper into material 100. Similarly, if
productive controller 402 determines that earthworking implement 16
is operating at a depth of cut deeper than an optimal predetermined
productivity, e.g., earthworking implement 16 may be unproductively
removing too great an amount of material 100, productive controller
402 may be configured to output command signal D.sub.P to command
controller 400 which would raise earthworking implement 16 higher
within material 100. As such, productive controller 402 may output,
to command controller 400, command signal D.sub.P adapted to
control the depth of cut of earthworking implement 16 within
material 100 to achieve a productive removal thereof. It is
contemplated that productive controller 402 may dynamically output
command signal D.sub.P to command controller 400 in response to
varying work site conditions and/or other conditions that may
affect command signal D.sub.P, such as, for example, operational
capabilities of earthworking machine 12 and/or material properties
of material 100.
[0016] For example, productive controller 402 may determine the
productive depth of cut and output command signal D.sub.P through a
predetermined algorithm as a function of signals received from a
ground speed sensor (not shown), a slope detector (not shown), a
slip detector (not shown), and/or a tilt sensor (not shown). The
power of earthworking implement 16 may be determined and/or based
in part on the sensed ground speed of earthworking machine 12, the
detected slope of work site 10, the detected slip of traction
device 24, the sensed tilt of earthworking implement 16, and/or the
relationships thereof with the amount of material 100 being removed
by earthworking implement 16. Productive controller 402 may be
configured to determine the productive depth of cut based in part
on the power of earthworking implement 16 determined by the
predetermined algorithm analyzing the sensed data and/or comparing
such data with look-up tables, databases, and/or other known
mathematical manipulations. Additionally, productive controller 402
may be configured to determine the actual depth of cut of
earthworking implement 16 in part based on the position of
earthworking implement 16 relative to earthworking machine 12
and/or surface 102 and compare the determined productive depth of
cut and the actual depth of cut to output command signal D.sub.P to
affect movement of earthworking implement 16 toward the productive
depth of cut. It is contemplated that productive controller 402,
through the predetermined algorithm, may also determine command
signal D.sub.P based in part on error feedback terms and
mathematical constants as is known in the art. Productive
controller 402 may embody any known or conventional apparatus and
method configured to maximize the productive removal of material
from a work site. It is further contemplated that productive
controller 402 may include any controller, method, and/or algorithm
configured to determine a depth of cut based on the power
capability of an earthworking implement by analyzing, sensing,
and/or monitoring known operational parameters of the earthworking
implement, an earthworking machine, and/or work site
properties.
[0017] Contour controller 404 may be configured to determine a
contour depth of cut of earthworking implement 16 relative to
surface 102 to remove material 100 from worksite 10 to achieve a
desired grade. Contour controller 404 may be further configured to
output a command signal D.sub.C, indicative of the determined
contour depth of cut, to command controller 400 to affect the
position of earthworking implement 16 in response to the determined
contour position. For example, if contour controller 404 determines
that earthworking implement 16 is operating at a depth of cut above
a predetermined desired grade, i.e., earthworking implement 16 is
not removing material that is desired to be removed, contour
controller 404 may be configured to output command signal D.sub.C
which would command controller 400 to lower earthworking implement
16 deeper into material 100. Similarly, if contour controller 404
determines that earthworking implement 16 is operating at a depth
of cut below a predetermined desired level, i.e., earthworking
implement 16 is removing material 100 that is desired to remain,
contour controller 404 may be configured to output command signal
D.sub.C which would command controller 400 to raise earthworking
implement 16 higher within material 100. As such, contour
controller 404 may output, to command controller 400, command
signal D.sub.C adapted to control the depth of cut of earthworking
implement 16 within material 100 to achieve a desired grade. It is
contemplated that contour controller 404 may additionally include
command outputs to control and/or operate warning signals, alarms,
visual displays, and/or other informational components that may be
activated to indicate an operating status of contour controller 404
and, in particular, earthworking implement 16 and earthworking
machine 12. It is contemplated that contour controller 404 may
dynamically output command signal D.sub.C to command controller 400
in response to varying work site conditions and/or other conditions
that may affect command signal D.sub.C, such as, for example,
varying depth of desired contour and/or varying contour of surface
102.
[0018] For example, contour controller 404 may determine the
contour depth of cut through a predetermined algorithm based in
part on work site geographies and may include a desired work site
geography model and an actual work site geography model. Contour
controller may be configured to receive an initial work site
geography determined, for example, by manual site survey, automated
site survey systems utilizing stereo photography and data
processors, and/or geological core sampling methods. The initial
work site geography model may be stored within a data storage
device (not shown) and configured to be accessible by a global
positioning system ("GPS") via the algorithm. As earthworking
machine 12 traverses work site 10, the GPS may be further
configured to monitor position coordinates of earthworking machine
12 relative to work site 10 and communicate data to the algorithm,
which in turn may determine the actual work site geography as
changes are made thereto by earthworking implement 16. Contour
controller 404 may also be configured to determine the position of
earthworking implement 16 relative to earthworking machine 12.
Contour controller 404 may be further configured to output command
signal D.sub.C based on the difference between the actual and
desired work site geography models to control earthworking
implement 16 and/or earthworking machine 12 to remove material 100
and bring the actual work site into conformity with the desired
work site geography model. It is further contemplated that contour
controller 404 may include any controller, method, and/or algorithm
configured to determine a depth of cut of an earthworking implement
based in part on a desired grade of a work site by analyzing,
sensing, and/or monitoring known operational parameters and/or
locations of the earthworking implement, an earthworking machine,
and/or work site properties.
[0019] Command controller 400 may be configured to monitor and
regulate command signals D.sub.P and D.sub.C outputted from
productive controller 402 and contour controller 404, respectively,
to thereby control movement of earthworking implement 16. Command
controller 400 may receive command signals D.sub.P and D.sub.C and
may determine which of command signals D.sub.P or D.sub.C would
control earthworking implement to operate at a higher depth of cut
within material 100. Command controller 400 may further be
configured to output a command signal D.sub.I indicative of one of
command signals D.sub.P and D.sub.C determined to control
earthworking implement 16 to a higher depth of cut. Command
controller 400 may further be configured to output command signal
D.sub.I to affect movement of hydraulic cylinder 20, via a
hydraulic circuit (not shown), to control earthworking implement 16
to a working depth of cut. Additionally, command controller 400 may
be configured to override the other one of command signals D.sub.P
and D.sub.C not determined to control earthworking implement 16 to
a higher depth of cut. It is contemplated that command controller
may allow the one of command signals determined to control
earthworking implement 16 to a higher depth of cut to directly
control hydraulic cylinder 20 to the working depth of cut. It is
also contemplated that command controller 400 may alternatively
control other components of earthworking machine 12 to affect the
movement of earthworking implement 16 to the working depth of cut,
such as, for example, hydraulic valve actuators, direct electronic
actuators, mechanically geared actuators, and/or other components
known in the art. It is also contemplated that command controller
400, productive controller 402, and contour controller 404 may be
integrated into a common controller. It is further contemplated
that command controller 400 may additionally affect and/or control
operation and movement of earthworking machine 12 over work site
10.
[0020] FIG. 3 illustrates an exemplary method 500 of command
controller 400 to control movement of earthworking implement 16.
Method 500 may include a comparing command signal D.sub.P and
command signal D.sub.C, step 502, outputting a command signal
D.sub.I indicative of command signal D.sub.C, step 504, and
outputting a command signal D.sub.I indicative of command signal
D.sub.P. Specifically, method 500 may compare command signals
D.sub.P and D.sub.C in step 502 and determine if command signal Dc
corresponds to a higher depth of cut than command signal D.sub.P.
If command signal D.sub.C corresponds to a higher depth of cut,
method 500 may progress to step 504 wherein command controller may
output command signal D.sub.I indicative of command signal D.sub.C.
If command signal D.sub.C does not correspond to a higher depth of
cut, method 500 may progress to step 506 wherein command controller
may output command signal D.sub.I indicative of command signal
D.sub.P.
[0021] Step 502 may compare command signals D.sub.P and D.sub.C and
determine if command signal D.sub.C would affect movement of
earthworking implement 16 to a higher depth of cut than command
signal D.sub.P. The comparison of command signals D.sub.P and
D.sub.C and the determination of whether command signal D.sub.C
would control earthworking implement 16 to a higher depth of cut
than would command signal D.sub.P may be determined by an algorithm
and may be based in part on look-up tables, calculations, and/or
other mathematically suitable methods known in the art to compare
signals.
[0022] Step 504 may include command controller 400 outputting
command signal D.sub.I configured to affect control of earthworking
implement 16 to a depth of cut indicative of command signal
D.sub.C. Specifically, command signal D.sub.I may be in part based
on command signal D.sub.C and may control the movement of
earthworking implement 16 via hydraulic cylinder 20. Additionally,
command controller 400 may prohibit command signal D.sub.P from
affecting movement of earthworking implement 16. Specifically,
command controller 400 may selectively suspend productive
controller 402 from outputting command signal D.sub.P.
[0023] For example, command controller 400 may selectively suspend
command signal D.sub.P from affecting movement of earthworking
implement 16. Command controller 400 may selectively suspend
command signal D.sub.P by an integrated circuit logic, an algorithm
and/or other control means known in the art. It is contemplated
that command controller 400 may also selectively suspend
calculation of any error feedback terms. Specifically, command
controller 400 may override the calculation of the error feedback
term by fixing the term to zero by an integrated circuit logic, an
algorithm and/or other control means known in the art. Selectively
overriding the calculation of any error feedback terms may
eliminate productive controller 402 from outputting command signal
D.sub.P which would affect a large actuation of earthworking
implement 16 when command controller 400 outputs command signal
D.sub.I indicative of command signal D.sub.P subsequent to
outputting command signal D.sub.I indicative of command signal
D.sub.C.
[0024] Step 506 may include command controller 400 outputting
command signal D.sub.I to affect control of earthworking implement
16 to a depth of cut indicative of command signal D.sub.P when
command signal D.sub.C is not higher than command signal D.sub.P.
Specifically, command signal D.sub.I may be based in part on
command signal D.sub.P and may control the movement of earthworking
implement 16 via hydraulic cylinder 20. Additionally, command
controller 400 may prohibit command signal D.sub.C from affecting
movement of earthworking implement 16. Specifically, command
controller 400 may selectively suspend contour controller 404 from
outputting command signal Dc and other command signals which would
control earthworking machine 12 and/or earthworking implement 16,
and also control additional instructional and/or warning signals
indicative of the operating status of contour controller 404 and
earthworking machine 12.
[0025] For example, command controller 400 may selectively suspend
command signal D.sub.C. Command controller 400 may selectively
suspend command signal D.sub.C by an integrated circuit logic, an
algorithm and/or other control means known in the art. It is
contemplated that command controller 400 may also selectively
suspend additional instructional and/or warning signals indicative
of the operating status of contour controller 404 and earthworking
machine 12 by an integrated circuit logic, an algorithm and/or
other control means known in the art.
[0026] Method 500 may additionally be configured to return to
control 502 after steps 504, 506. Specifically, subsequent to
command controller outputting command signal D.sub.I indicative of
command signal D.sub.C or D.sub.P, command controller may monitor
and again compare command signals D.sub.C and D.sub.P. After a
subsequent determination in step 502 regarding command signals
D.sub.C and D.sub.P, method 500 may progress to step 504 or step
506 and method 500 may be repeated as necessary or desired by an
operator to remove material 100 from work site 10. As such, method
500 may continuously monitor and compare command signals D.sub.C
and D.sub.P and command controller 400 may dynamically output
command signal D.sub.I indicative of the one of command signals
D.sub.C and D.sub.P that would control earthworking implement to a
higher depth of cut. It is contemplated that method 500 may further
include additional steps such as, for example, an initialization
step (not shown), an end step (not shown), a suspend/pause step
(not shown), or other control features known in the art.
INDUSTRIAL APPLICABILITY
[0027] The disclosed method and apparatus of controlling an
earthworking implement may be applicable to any earthworking
machine that removes material from a work site. The disclosed
method and apparatus may provide productive material removal while
bringing actual work site geography into desired work site
geography. The operation of the method and apparatus of controlling
earthworking implement 16 is explained below.
[0028] Earthworking machine 12 may be used to remove material 100
from work site 10 to achieve a desired grade. Specifically,
earthworking machine 12 may traverse work site 10 to remove
material 100 to expose a layer of desired material and/or provide a
desired contour. As earthworking machine 12 traverses work site 10,
earthworking implement 16 may be raised and/or lowered relative to
surface 102 of material 100 to affect the removal of material 100
from work site 10. As earthworking implement 16 affects removal of
material 100, control system 18 may monitor and control the
position of earthworking machine 12 relative to work site 10 and
the position of earthworking implement 16 relative to earthworking
machine 12 to productively remove material 100 while achieving a
desired grade.
[0029] As earthworking machine traverses work site 10, productive
controller 402 may output control signal D.sub.P to command
controller 400 that would control earthworking implement 16 to be
moved relative to surface 102. Specifically, productive controller
402 may determine that earthworking implement, and earthworking
machine 12, may be capable of removing more material 100 than that
currently being removed and/or may be currently be removing too
much material 100. Substantially simultaneously, contour controller
404 may output command signal D.sub.C to command controller 400
that would control earthworking implement 16 to be moved relative
to surface 102. Specifically, contour controller 404 may determine
that surface 102 of material 100 is not the desired grade and thus
that material 100 needs to be removed and/or that surface 102 is
the desired grade and that no material 100 needs to be removed.
[0030] Command controller 400 may compare (referring to FIG. 3)
command signals D.sub.P and D.sub.C to determine which of command
signals D.sub.P and D.sub.C is configured to control earthworking
implement 16 to a higher depth of cut below surface 102. Command
controller 400 may then output command signal D.sub.I, indicative
of the one of productive controller 402 and contour controller 404
that would control earthworking implement 16 to a higher depth of
cut to thereby control earthworking implement 16. For example, if
command controller 400 determines that command signal D.sub.C would
control earthworking implement 16 to a higher depth of cut (i.e.,
productive controller 402 would control earthworking implement
below the desired grade), command controller 400 may output command
signal D.sub.I indicative of command signal D.sub.C to control
earthworking implement 16. Similarly, if command controller 400
determines that command signal D.sub.P would control earthworking
implement 16 to a higher depth of cut (i.e., contour controller 404
would control earthworking implement 16 to a depth at which
earthworking implement 16 may no longer productively remove
material 100), command controller 400 may output command signal
D.sub.I indicative of command signal D.sub.P to control
earthworking implement 16. It is contemplated that command
controller 400 may, alternatively, allow the one of command signals
D.sub.P and D.sub.C that would control earthworking implement 16 to
a higher depth of cut to directly control earthworking implement
16.
[0031] The following operation of control system 18, and in
particular, command controller 400 is illustrated with reference to
earthworking machine 12 during several passes across work site 10
from a unmodified work site toward a desired grade. It is noted
that the explanation below is for clarification purposes only, and
the method and apparatus may be applicable for any earthworking
machine at any status of material removal from work site 10.
[0032] For example, as earthworking machine 12 makes a first pass
across work site 10, earthworking implement 16 may be positioned
above surface 102 and may not remove material 100. It is likely,
however, that surface 102 may not be at the desired grade and both
productive controller 402 and contour controller 404 may determine
and output respective command signals D.sub.P and D.sub.C that
would lower earthworking implement 16 below surface 102.
Specifically, productive controller 402 may output a command signal
D.sub.P to command controller 400 that would lower earthworking
implement 16 to a productive depth of cut to productively remove
material 100. Similarly, contour controller 404 may substantially
simultaneously output command signal D.sub.C to command controller
400 that would lower earthworking implement 16 toward a contour
depth of cut to achieve a desired grade. It is noted that command
signals D.sub.P and D.sub.C may each affect a lowering of
earthworking implement 16 toward the desired grade of work site 10.
Command controller 400 may monitor and determine which of command
signals D.sub.P and D.sub.C would control earthworking implement 16
to a higher depth of cut (see FIG. 3, step 502). Because surface
102 may not be at the desired grade, command controller 400 may
move earthworking implement 16 lower into material 100 below
surface 102 in response to one of command signals D.sub.P or
D.sub.C. It is contemplated that earthworking implement 16 may
gradually be lowered into material 100 below surface 102 to begin
removing material 100 due to movement of earthworking machine 12
relative to work site 10 and time necessary to move earthworking
implement 16 from an preexisting depth of cut to subsequent depth
of cut.
[0033] Assuming that a relatively small amount of material 100 is
desired to be removed from work site 10, command signal D.sub.C may
control earthworking implement 16 to a higher depth of cut than
would command signal D.sub.P. Specifically, command controller 400
may determine that command signal D.sub.C would control
earthworking implement 16 to a higher depth of cut than would
command signal D.sub.P (see FIG. 3, step 502) and may output
command signal D.sub.I to control earthworking implement 16 to a
depth of cut indicative of command signal D.sub.C (see FIG. 3, step
504). For example, earthworking machine 12 may be capable of moving
a large amount of material 100 but only a relatively small amount
of material needs to be removed to achieve the desired grade. As
such, productive controller 402 may output command signal D.sub.P
that would, if allowed to control earthworking implement 16, lower
earthworking implement 16 below the desired grade, which may be
undesirable.
[0034] As earthworking machine 12 continues the first pass across
work site 10 with earthworking implement 16 controlled below
surface 102 of material 100, the amount of material 100 removed by
earthworking implement 16 may increase. Specifically, newly removed
material 100 may combine with previously removed material 100 and
may build up in front of earthworking implement 16. As the amount
of removed material 100 increases, earthworking implement 16 may no
longer be able to productively remove material 100 at the contour
depth of cut and productive controller 402 may output command
signal D.sub.P that would control earthworking implement 16 at a
higher depth of cut than would command signal D.sub.C.
[0035] Command controller 400 may continually monitor command
signals D.sub.C and D.sub.P, and may determine that command D.sub.P
would control earthworking implement 16 to a higher depth of cut
than would command signal D.sub.C (see FIG. 3, step 502) and may
output command signal D.sub.I to control earthworking implement 16
to a depth of cut indicative of command signal D.sub.P (see FIG. 3,
step 506). For example, earthworking implement 16 may no longer be
capable of productively removing material 100 at the desired grade
as controlled by contour controller 404 because of the increasing
amount of material 100 removed by earthworking implement 16. As a
result, earthworking implement 16 may be raised to a higher depth
of cut, i.e., earthworking implement 16 may no longer be controlled
to the contour depth of cut and instead may be controlled to the
productive depth of cut.
[0036] As earthworking machine 12 continues the first pass, contour
controller 404 may monitor the desired work site geography and the
actual work site geography and dynamically output command signal
D.sub.C to affect earthworking implement 16 toward a contour depth
of cut. Similarly, productive controller 402 may monitor the
operating conditions of earthworking machine 12 and/or earthworking
implement 16 and dynamically output command signal D.sub.P to
affect earthworking implement 16 toward a productive depth of cut.
Accordingly, command controller 400 may monitor dynamically
outputted command signals D.sub.C and D.sub.P and may thus
dynamically output command signal D.sub.I to dynamically control
the depth of earthworking implement 16. For example, the desired
geography and/or actual geography of work site 10 may vary and
command signals D.sub.C and D.sub.P may correspondingly vary
depending upon the location of earthworking machine 12 relative to
work site 10 and/or the amount of material desired to be removed.
For example, the actual and/or desired grade may include variable
slopes and as a result may include a dynamically changing
difference between the actual grade and the desired grade resulting
in contour controller 404 and productive controller 402 dynamically
determining command signals D.sub.C and D.sub.P that would control
earthworking implement 16 to respective dynamic depths of cut.
[0037] As earthworking machine 12 makes a second pass across work
site 10, earthworking implement 16 may be positioned above surface
102. However, surface 102 may now be at the desired grade because
during the first pass, contour controller 404 affected control of
earthworking implement 16 to the desired grade. Accordingly,
contour controller 404 may output command signal D.sub.C that would
not lower earthworking implement below surface 102 because the
desired grade has been achieved. However, because earthworking
implement 16 may not be removing material 100, productive
controller 402 may output command signal D.sub.P that would lower
earthworking implement below surface 102 because earthworking
implement 16 is capable of productively removing more material 100.
Controller 400 may monitor command signals D.sub.C and D.sub.P and
output command signal D.sub.I indicative of command signal D.sub.C
to control earthworking implement 16.
[0038] As earthworking machine 12 continues the second pass,
surface 102 may at some point no longer be at the desired grade.
This may occur because earthworking implement 16 may have been
raised during the first pass in response to command signal D.sub.P.
Accordingly, contour controller 404 and productive controller 402
may determine and output respective command signals D.sub.C and
D.sub.P that would lower earthworking implement 16 below surface
102. Again assuming a relatively small amount of material 100 is
desired to be removed, controller 400 may output command signal
D.sub.I indicative of command signal D.sub.C to control
earthworking implement 16 toward the contour depth of cut. As
earthworking machine 12 continues the second pass, and similar to
the first pass, the amount of material 100 removed by earthworking
implement 16 may increase and earthworking implement 16 may no
longer be able to productively remove material 100 at the contour
depth. Productive controller 402 may output command signal D.sub.P
that would control earthworking implement 16 at a higher depth of
cut than would command signal D.sub.C and accordingly, controller
400 may output command signal D.sub.I indicative of command signal
D.sub.P to control earthworking implement 16.
[0039] As earthworking machine 12 makes subsequent passes across
work site 10, the operation explained above may be continued as
necessary to achieve the desired grade. Each subsequent pass may
bring the actual work site geography closer toward the desired work
site geography. It is contemplated that work machine 12 may begin
subsequent passes at the point where surface 102 of material 100 is
no longer at the desired grade. Specifically, earthworking machine
may not need to start subsequent passes at the same origin as
previous passes because the desired grade may have been achieved
therein.
[0040] Because command controller 400 monitors command signals
D.sub.P and D.sub.C and controls earthworking implement 16 in
response to the one of command signals D.sub.P and D.sub.C that
would control earthworking implement to a higher depth of cut,
removal of material from work site 10 may be performed productively
and to a desired grade. This monitoring may eliminate the
unintended removal of material desired to remain in work site 10
and may increase the productive removal of material that is desired
to be removed. The overall productivity of transforming a work site
from actual geography to desired geography may be increased.
[0041] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed method
and apparatus for controlling an earthworking implement. Other
embodiments will be apparent to those skilled in the art from
consideration of the specification and practice of the disclosed
method and apparatus for controlling an earthworking implement. It
is intended that the specification and examples be considered as
exemplary only, with a true scope being indicated by the following
claims and their equivalents.
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