(12) United States Patent
`US 6,286,606 B1
`(10) Patent N0.:
`(45) Date of Patent:
`Krieg et al.
`Sep. 11, 2001
`
`USOO6286606B1
`
`(54)
`
`(75)
`
`METHOD AND APPARATUS FOR
`CONTROLLING A WORK IMPLEMENT
`
`Inventors: Randy K. Krieg, Wasilla, AK (US);
`John J. Cheek, Washington, IL (US)
`
`(73)
`
`Assignee: Caterpillar Inc., Peoria, IL (US)
`
`(*)
`
`Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`
`(21)
`
`(22)
`
`(60)
`
`(51)
`(52)
`
`(58)
`
`(56)
`
`Appl. No.: 09/370,868
`
`Filed:
`
`Aug. 9, 1999
`
`Related US. Application Data
`Provisional application No. 60/112,959, filed on Dec. 18,
`1998.
`
`Int. Cl.7 ........................................................ E02F 3/76
`US. Cl.
`........................... 172/4.5; 172/779; 172/821;
`172/812; 701/50
`Field of Search ................................. 172/4.5, 2, 779,
`172/818—821, 812; 701/50
`
`References Cited
`
`12/1992 Nakamura et al.
`5,170,342
`12/1993 Moriya et al.
`.
`5,274,557
`.
`7/1994 Nielsen et al.
`5,327,345
`10/1994 Hanamoto et al.
`5,356,259
`7/1995 Nielsen et al.
`.
`5,430,651
`3/1996 Stratton .
`5,499,684
`9/1996 Stratton .
`5,551,518
`.
`5/1997 Gudat et al.
`5,631,658
`.
`7/1997 Burdick et al.
`5,647,439
`....................... 172/781
`9/1997 Palmer et al.
`5,667,020
`4/1998 Henderson et al.
`.
`5,735,352
`4/1999 Szymczak .
`5,894,894
`5/1999 Rohrbaugh et al.
`5,905,986
`9/1999 Kawakami et al.
`5,947,225 *
`9/1999 Sahm .
`5,951,612
`.
`11/1999 Bailey et al.
`5,987,371
`FOREIGN PATENT DOCUMENTS
`
`.
`
`.
`
`.
`
`................. 180/271
`
`1390066
`57—071939
`58164835
`59102023
`
`4/1975 (GB).
`5/1982 (JP).
`9/1983 (JP).
`6/1984 (JP).
`
`* cited by examiner
`
`Primary Examiner—Christopher J. Novosad
`(74) Attorney, Agent, or Firm—Wood, Herron & Evans,
`LLP; John J. Cheek; Thomas L. Derry
`
`U.S. PATENT DOCUMENTS
`
`(57)
`
`ABSTRACT
`
`4,136,508
`4,185,700
`4,221,266
`4,286,386
`4,288,196
`4,646,620
`4,733,310 *
`4,733,355
`4,744,218
`4,912,643
`4,918,608
`4,934,463
`4,955,437
`5,065,326
`5,078,215
`
`.
`..................... 172/796
`
`1/1979 Coleman et al.
`1/1980 Atherton et al.
`9/1980 Fardal .
`9/1981 Long .
`9/1981 Sutton .
`3/1987 Buchl .
`.......................... 358/300
`3/1988 Kapp et al.
`3/1988 Davidson et al.
`.
`5/1988 Edwards et al.
`3/1990 Beirxe.
`.
`4/1990 Middleton et al.
`6/1990 Ishida et al.
`.......................... 172/4.5
`9/1990 Bohman .
`11/1991 Sahm .
`1/1992 Nau ....................................... 172/4.5
`
`.
`
`A method and apparatus for controlling a work implement
`movably connected to a work machine. An implement
`controller automatically controls simultaneous first and sec-
`ond control modes of operation assigned to the work imple-
`ment. A sensor applies a signal to the implement controller
`indicating position of the work implement. The implement
`controller reverses the simultaneous first and second control
`
`modes assigned to the work implement upon detecting a
`predetermined movement of the work movement. The
`simultaneous first and second control mode assignments
`may also be changed by actuation of a manually actuatable
`device.
`
`26 Claims, 4 Drawing Sheets
`
`30
`
`
`
`
`S38
`S38
`f263
`GRADE SENSOR MODE!
`AUTO/
`AUTO/
`SLOPE SENSOR MODE
`SLOPE SENSOR MODE
`MANUAL
`MANUAL
`GRADESENSORMODE/T!
`
`
`
`
`
`SELECT SWITCH
`SELECT SWITCH
`MODE SWITCH MODE SWITCH
`
`
`
`
` 49
`
`Lfill
`
`
`
`‘flig
`
`
`AUTOMATIC
`(36 28\
`IMPLEMENT
`
`AUTOMATIC
`CONTROLLER
`
`AUTOMATIC
`
`MODE SWAP
`CONTROL
`GRADE GRADE
`
`CONTROL
`
`
`30
`SWITCH
`
`
`
`VALVES
`SLOPE
`SLOPE
`
`
`VALVES
`
`
`
`gs4
`3 MANUAL
`36)
`MANUAL
`-
`CONTROL
`44 MACHINE =RAME
`
`45«\
`CONTROL
`L VALVE 4'
`SENSOR
`
`
`
`
`
`
`
`
`
`‘8
`1] ,7 VALVE
`
`
`\ 20
`234
` CROSS SLOPE
`
`E
`
`20
`
`42
`
`12/
`
`
`
`Page 10f10
`
`CATERPILLAR EXHIBIT 1006
`
`Page 1 of 10
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`CATERPILLAR EXHIBIT 1006
`
`

`

`US. Patent
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`US 6,286,606 B1
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`
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`Page 2 of 10
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`Page 2 of 10
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`

`

`US. Patent
`
`Sep. 11,2001
`
`Sheet 2 0f 4
`
`US 6,286,606 B1
`
`8F;E_Ea_
`
`GRADE SENSOR MODE/
`SLOPE SENSOR MODE
`SELECT SWITCH
`
`AUTO/
`AUTO/
`MANUAL
`MANUAL
`MODE SWITCH MODE SWITCH
`
`GRADE SENSOR MODE/
`SLOPE SENSOR MODE
`SELECT SWITCH
`
`36
`28
`IMPLEMENT
`
`
`
`CONROGLLER
`AUTOMATIC
`CONTROL
`RAD__|
`
`
`-
`*——
`
`VALVES
`
`30
`
`34
`
`MANUAL
`
`- CONTROL.
`
`VALVE
`
`AUTOMATIC
`AUTOMATIC MODE SWAP
`VAL-VES
`
`CONTROL
`
`SWITCH
`
`MANUAL
`CONTROL -
`VALVE
`
`34
`
`30
`
`
`m
`
`-.14
`I 39
`
`46
`
`CROSS SLOPE
`
`I
`
`45
`
`12/'
`
`39
`
`Page 3 0f 10
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`Page 3 of 10
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`

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`US. Patent
`
`Sep. 11,2001
`
`Sheet 3 0f 4
`
`US 6,286,606 B1
`
`FLE_EI:I_
`
`GRADE SENSOR MODE/
`SLOPE SENSOR MODE
`SELECT SWITCH
`
`AUTO/
`AUTO/
`MANUAL
`MANUAL
`MODE SWITCH MODE SWITCH
`
`GRADE SENSOR MODE/
`SLOPE SENSOR MODE
`SELECT SWITCH
`
`I
`
`
`
`14
`
`39
`
`-
`
`3°
`
`CROSS SLOPE
`
`
`
`IMPLEMENT
`28
`C-GONTRQLLER
`
`
`AUTOMATIC
`_-__
`AUTOMATIC
`AUTOMATIC MODE SWAP
`CONTROL
`Ll__R_A—DE
`
`SWITCH
`CONTROL
`
`S_=LOPEE-_SOPE
`VALVES
`
`
`
`VAL-VES
`
`MANUAL -
`-- CONTROL
`VALVE
`- CONTROL.
`MANUAL
`VALVE
`34
`
`36
`
`30
`
`34
`
`12/
`
`46
`
`Page 4 of 10
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`Page 4 of 10
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`

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`US. Patent
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`Sep. 11,2001
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`Sheet 4 0f 4
`
`US 6,286,606 B1
`
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`TE £191 E-j'l 7\~
`
`Page 5 0f 10
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`Page 5 of 10
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`

`US 6,286,606 B1
`
`1
`METHOD AND APPARATUS FOR
`CONTROLLING A WORK IMPLEMENT
`
`This application claims the benefit of prior provision
`patent application Serial No. 60/112,959 filed Dec. 18, 1998.
`TECHNICAL FIELD
`
`The present invention relates generally to manual and
`automatic positioning of a work implement and, more
`particularly,
`to a method and apparatus for controlling
`modes of operation of a work implement of a work machine.
`BACKGROUND ART
`
`Work machines, such as motor graders, dozers,
`compactors, pavers, profilers and scrapers, are used for
`geographic surface altering operations. The machines
`include a work implement, such as a surface altering blade,
`that is movably connected to a frame of the machine by one
`or more hydraulic motors or cylinders, or the work imple-
`ment may be fixed to the machine frame. The position of the
`blade relative to the work surface must be accurately con-
`trolled to achieve the desired surface altering cut.
`In motor graders, for example, the surface altering blade
`is movably connected to the grader frame by a pair of
`independently actuatable hydraulic lift cylinders that are
`mounted on either side of the machine frame. The hydraulic
`lift cylinders are independently extensible and retractable to
`move corresponding sides of the blade relative to the
`machine frame. Each side of the blade may be set by the
`operator to operate in either a “manual” or “automatic”
`mode of operation. In either mode, each side of blade is also
`assignable by the operator to operate in a “grade sensor”,
`“slope sensor” or “down force” mode of operation. Control
`for each side of the blade is independently assignable to one
`of the “grade sensor”, “slope sensor” and “down force”
`modes of operation such that both sides may be assigned to
`“grade sensor” or “down force” modes, or one side assigned
`to “grade sensor” or “down force” mode while the other side
`is assigned to the “slope sensor” mode.
`When “grade sensor” (or “down force”) and “slope sen-
`sor” modes are assigned simultaneously to the opposite sides
`of the blade, the leading end or toe of the blade is generally
`assigned to the “grade sensor” mode, and the trailing or heel
`of the blade is assigned to the “slope sensor” mode. In
`“automatic” mode, a grade sensor maintains the grade sensor
`controlled side of the blade at a preselected position relative
`to a grade reference point. The elevation of the slope
`controlled side of the blade is controlled by a programmed
`cross slope value selected by the operator and stored in an
`implement controller that controls the “grade sensor”,
`“down force” and “slope sensor” modes of operation.
`During a grading operation in one direction, the operator
`rotates the blade to a desired grading angle relative to the
`machine frame and may assign the “grade sensor” (or “down
`force”) and “slope sensor” control modes to the opposite
`sides of the blade. On a return grading pass in the opposite
`direction,
`the operator must rotate the blade to a mirror
`angle, and manually switch the “grade sensor” (or “down
`force”) and “slope sensor” modes assigned to the opposite
`sides of the blade. To achieve the switch of the control
`
`modes, the operator must manually actuate control switches
`that are located in the cab.
`
`During the motor grader reconfiguration process for the
`return grading pass, the operator may improperly reassign
`the control modes of operation to the blade which may result
`in the wrong cross slope cut. Moreover, the manual recon-
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`2
`figuration process required for grading in opposite directions
`reduces the operator’s accuracy and efficiency.
`The present invention is directed to overcoming one or
`more of the problems as set forth above.
`DISCLOSURE OF THE INVENTION
`
`The present invention overcomes the foregoing and other
`shortcomings and drawbacks of work implement positioning
`and methods heretofore known. While the invention will be
`described in connection with certain embodiments, it will be
`understood that the invention is not limited to these embodi-
`
`the invention includes all
`ments. On the contrary,
`alternatives, modifications and equivalents as may be
`included within the spirit and scope of the present invention.
`In one aspect of the invention, an apparatus for controlling
`a work implement of a work machine in simultaneous first
`and second control modes of operation is provided. An
`implement controller is operable to assign the first and
`second control modes of operation to the work implement.
`Positioning mechanisms may be connected to each side of
`the work implement for altering the position of each side of
`the work implement.
`One of the positioning mechanisms may be operable to
`move one side of the work implement to a first position, and
`the other positioning mechanism may be operable to move
`the other side of the work implement to a second position.
`Asensor is associated with the work implement and coupled
`to the implement controller for applying a signal to the
`implement controller indicating position of the work imple-
`ment. The implement controller is operable to change the
`control mode assignments to the work implement upon
`determining a predetermined movement of the work imple-
`ment as indicated by the sensor, such as a predetermined
`rotation of the work implement. Upon determining a prede-
`termined movement of the work implement, the implement
`controller may be operable to reverse the first and second
`control mode assignments to the work implement, and may
`also be operable to reverse the first and second positions of
`the work implement as well.
`In another aspect of the invention, a drive mechanism may
`be operatively connected to the work implement for moving
`the work implement between a first rotational position and
`a second rotational position under control of the implement
`controller. A manually actuatable device is electrically
`coupled to the implement controller. The implement con-
`troller is operable to reverse the control assignments to, and
`the rotational position of, the work implement upon actua-
`tion of the manually actuatable device.
`In yet another aspect of the invention, a method for
`controlling a work implement of a work machine in simul-
`taneous first and second control modes of operation is
`provided. First and second automatic control modes are
`assigned to the work implement. Movement of the work
`implement is sensed and, upon a predetermined movement
`of the work implement as detected during the sensing step,
`the first and second control modes assigned to the work
`implement are reversed.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`For better understanding of the present invention, refer-
`ence may be made to the accompanying drawings in which:
`FIG. 1 is a partial perspective view of a motor grader
`including an implement control system for controlling con-
`trol modes of a work implement;
`FIGS. 2A and 2B are diagrams, partly schematic and
`partly block, showing front views of the motor grader of
`
`Page 6 0f 10
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`Page 6 of 10
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`

`

`US 6,286,606 B1
`
`3
`FIG. 1 traveling in opposite grading directions, and an
`implement control system for controlling control modes of
`a work implement as applied to a grader blade of the motor
`grader shown in FIG. 1; and
`FIG. 3 is a top plan view of the motor grader shown in
`FIG. 1.
`
`BEST MODE FOR CARRYING OUT THE
`INVENTION
`
`With reference to the figures, and to FIG. 1 in particular,
`a work machine 10,
`illustrated as a geographic surface
`altering motor grader,
`is shown including an implement
`control system 12 (FIGS. 2A—2B) for controlling control
`modes of a work implement 14, illustrated as a conventional
`grader blade. The work implement 14 is part of a blade
`sub-assembly,
`indicated generally at 16, that is movably
`mounted to a frame 18 of the motor grader 10 through a pair
`of selectively actuatable hydraulic motors or lift cylinders 20
`that are connected between the machine frame 18 and the
`
`blade sub-assembly 16. The blade sub-assembly 16 includes
`a circle draw bar,
`indicated generally at 22, a circle 23
`(FIGS. 2A and 2B) rotatably mounted to the circle draw bar
`22, and grader blade 14 mounted to the circle 23. A selec-
`tively actuatable circle drive 24 (FIGS. 2A and 2B) is
`mounted to the circle draw bar 22 for rotating the circle 23
`and the blade 14 mounted thereto about an elevational axis
`
`25 (FIG. 3) located at the center of the circle 23 in a known
`manner. While the implement control system 12 will be
`described in detail below as applied to a motor grader, it will
`be appreciated by those skilled in the art that other geo-
`graphic surface altering machines, such as dozers,
`compactors, pavers, profilers, scrapers and the like,
`equipped with suitable surface altering implements, are
`equivalents and considered within the scope of the inven-
`tion.
`
`the implement
`With reference to FIGS. 2A and 2B,
`control system 12 is shown applied to motor grader 10 and,
`in particular, to the grader blade 14. During operation of the
`motor grader 10, the grade and cross-slope positions of blade
`14 may be controlled by manual and/or automatic extension
`and retraction of the hydraulic lift cylinders 20 connected to
`the blade sub-assembly 16. The pair of hydraulic lift cylin-
`ders 20 are extensibly movable to elevationally move cor-
`responding sides of the blade 14 relative to the frame 18.
`Each side of the blade 14 may be manually set by the
`operator to operate in either “manual” or “automatic” con-
`trol modes of operation through a pair of mode select
`switches 26 that are each dedicated to a corresponding side
`of blade 14. Control for each side of the blade 14 is
`
`independently assignable to one of the “manual” and “auto-
`matic” control modes of operation such that both sides may
`be assigned to “manual” mode, one side may be assigned to
`“manual” mode while the other side is assigned to “auto-
`matic” mode, or both sides may be assigned to “automatic”
`mode. The mode select switches 26 are electrically coupled
`to an implement controller 28 that is responsible for con-
`trolling the side of blade 14 that is assigned to the “auto-
`matic” mode of operation as described in greater detail
`below. Implement controller 28 includes a processor (not
`shown) of any suitable kind, such as a microprocessor
`having appropriate control software and memory (not
`shown) to store the selected “manual” and “automatic”
`control modes of operation for each side of blade 14.
`In the “manual” control mode, the operator controls the
`elevational position of one or both sides of the blade 14
`through a pair of implement positioning devices, such as a
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`that are
`levers 30,
`pair of manually actuatable control
`located within a cab 32 (FIG. 1) of the motor grader 10. Each
`of the manually actuatable control levers 30 is connected to
`a manually actuatable or manual control valve 34. The pair
`of manual control valves 34 are each connected between a
`
`hydraulic fluid supply (not shown), and a corresponding one
`of the hydraulic lift cylinders 20 mounted on a respective
`side of machine frame 18. Movement of each control lever
`30 in one direction allows hydraulic fluid to flow under
`pressure through the manual control valves 34 to actuate the
`hydraulic lift cylinders 20 to an extended or retracted
`position. Movement of each control lever 30 in the opposite
`direction causes a reverse directional movement of the
`
`hydraulic lift cylinders 20. In a neutral position of control
`levers 30, the manual control valves 34 assume a neutral or
`dead position that inhibits hydraulic fluid flow through the
`manual control valves 34.
`
`Further referring to FIGS. 2A and 2B, a pair of electrically
`actuatable or automatic control valves 36 are connected
`
`between the hydraulic fluid supply (not shown) and a
`corresponding one of the hydraulic lift cylinders 20 to
`control extension and retraction of the corresponding
`hydraulic lift cylinder 20 in the “automatic” control mode.
`The automatic control valves 36 are electrically coupled to
`the implement controller 28 for receiving command signals
`from the implement controller 28 to adjust the elevational
`position of a corresponding blade side through actuation of
`a respective hydraulic lift cylinder 20. The automatic control
`valves 36 are connected in parallel with the manual control
`valves 34, and are operable independently from the manual
`control valves 34 as described in detail below.
`
`In the “automatic” control mode, for example, each side
`of blade 14 may be assigned by the operator to a “grade
`sensor” mode or a “slope sensor” mode through a pair of
`sensor select switches 38 that are each dedicated to a
`
`corresponding side of blade 14. Other sensor modes are
`possible as well. For example, while not shown, each side of
`blade 14 is assignable to a “down force” mode of operation.
`Control for each side of blade 14 is independently assignable
`to one of the “grade sensor”, “down force” and “slope
`sensor” modes of operation such that both sides may be
`assigned to “grade sensor” mode, both sides may be
`assigned to “down force” mode, or one side may be assigned
`to “grade sensor” or “down force” mode while the other side
`is assigned to the “slope sensor” mode. The assigned sensor
`modes for each side of blade 14 are stored in memory (not
`shown) of the implement controller 28. For simplicity of
`discussion, only the “grade sensor” and “slope sensor”
`modes of operation will be described hereinafter in the
`automatic operation of motor grader 10. However, it will be
`appreciated that the “grade sensor”, “down force” and “slope
`sensor” modes of operation may also be assigned to corre-
`sponding sides of blade 14 in the “manual” control mode as
`well.
`
`In “grade sensor” mode, an ultrasonic sensor or a laser
`sensor, both indicated generally at 39, (FIGS. 2A and 2B),
`may be used to control
`the elevational position of the
`respective blade side relative to a grade reference point, such
`as a finished surface, curb, gutter, stringline or laser refer-
`ence beam. The ultrasonic sensors or laser sensors 39 are
`
`coupled to the implement controller 28, and provide signals
`to the implement controller 28 indicating the elevational
`position of the corresponding side of blade 14.
`In “grade sensor” mode, the grade sensor controlled side
`of blade 14 is maintained generally at a preselected eleva-
`tional position or grade by the implement controller 28 that
`continuously compares the actual elevational position as
`
`Page 7 0f 10
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`US 6,286,606 B1
`
`5
`
`determined by the grade sensor (not shown) with a desired
`grade setting selected by the operator. The implement con-
`troller 28 makes compensating elevational adjustments of
`the grade controlled side of the blade 14 through actuation
`of the corresponding hydraulic lift cylinder 20 as required.
`The operator selected “grade sensor” mode elevational value
`(or pair of values if both blade sides are assigned to the
`“grade sensor” mode) is assigned to the implement control-
`ler 28 through a corresponding one (or both) of a pair of
`momentary rocker switches (not shown) that are electrically
`coupled to the implement controller 28.
`A two-aXis blade slope sensor, indicated generally at 40
`(FIGS. 2A and 2B) is mounted on the blade sub-assembly 16
`to provide blade pitch and blade roll signals to the imple-
`ment controller 28 through electrical leads (not shown). In
`the “automatic” control mode, each side of the blade 14 may
`alternatively be assigned to a “slope sensor” mode in which
`the grade sensor controlled side of the blade 14 is maintained
`at the preselected elevational position as described above,
`while the implement controller 28 controls the cross slope of
`the “slope sensor” controlled blade side according to a
`kinematic control algorithm performed by the implement
`controller 28. As used herein, “cross slope” is the slope of a
`cut made by the blade 14 perpendicular to the direction of
`machine travel. The implement controller 28 receives the
`blade pitch and blade roll signals from the two-axis blade
`slope sensor 40, as well as signals from a blade rotation
`sensor 42 indicating blade rotation, and machine frame pitch
`and machine frame roll from a two-axis machine frame
`sensor 44 mounted to machine frame 18. Each of these
`
`values is taken into account by the kinematic control algo-
`rithm to accurately control the cross slope of the slope
`controlled side of the blade 14.
`
`In “slope sensor” mode, the slope sensor controlled side
`of the blade 14 is maintained generally at a preselected
`elevational position as defined by the elevational position of
`the grade controlled side of blade 14 and the operator
`selected cross slope value. The implement controller 28
`continuously compares the actual cross slope value com-
`puted from the various sensor signals with the desired cross
`slope, and makes compensating elevational adjustments
`through actuation of the corresponding hydraulic lift cylin-
`der 20 as required. The operator selected “slope sensor”
`mode elevational value, i.e, cross slope value, is assigned to
`the implement controller 28 through a touch pad set point
`capture button. The cross slope value can be modified by a
`corresponding one of the pair of momentary rocker switches
`(not shown) electrically coupled to the implement controller
`28.
`
`During a grading operation, as shown in FIGS. 1 and 3,
`the operator rotates the blade 14 to a desired grading angle
`relative to machine frame 18 through actuation of circle
`drive 24. Typically, most grading operations are performed
`with the blade 14 rotated clockwise or counterclockwise at
`
`an angle “ ” between about 10° and about 45° relative to an
`aXis 43 transverse to machine frame 18. As the motor grader
`10 grades in opposite passes (or directions) as shown in
`FIGS. 2A and 2B, both sides of blade 14 may be assigned to
`the “automatic” control mode of operation, with one or both
`sides of blade 14 assigned to “grade sensor” (or “down
`force”) mode, or one side assigned to “grade sensor” (or
`“down force”) mode and the other side assigned to “slope
`sensor” mode. When “grade sensor” and “slope sensor”
`modes are assigned simultaneously to the opposite sides of
`blade 14 as shown in FIGS. 2A and 2B, the leading end or
`toe 45 of blade 14 is typically assigned to the “grade sensor”
`mode, and the trailing end or heel 46 of blade 14 is assigned
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`to the “slope sensor” mode. When the operator changes
`directions to grade in the opposite direction, the blade 14 is
`rotated to a mirror angular position, as indicated generally at
`48.
`
`the rotational
`invention,
`In one aspect of the present
`position of blade 14 relative to machine frame 18 is provided
`by blade rotation sensor 42 (FIGS. 2A and 2B) to the
`implement controller 28 as a pulse width modulation
`(PWM) signal. The implement controller 28 converts the
`PWM signal from blade rotation sensor 42 to a rotational
`position value and determines if blade 14 has been rotated
`through a preselected angle “ ”, referred to hereafter as the
`“swap position”. Blade rotation sensor 42 may include
`potentiometers (not shown),
`limit switches (not shown),
`electromechanical actuators (not shown), encoders (not
`shown), or equivalent sensors associated with circle 23 and
`blade 14 for providing signals to implement controller 28
`that indicate the rotational position of blade 14 relative to a
`fixed reference point. Alternatively, the blade rotation signal
`applied to implement controller 28 may be generated by
`sensors (not shown) located in the environment of motor
`grader 10 that are operable to detect a rotated position of
`blade 14.
`
`As shown in FIG. 2A, in one grading pass of motor grader
`10, the right side or toe 45 of blade 14 (as viewed from
`within cab 32) is assigned to the “grade sensor” mode of
`operation, and is elevated in position relative to the left side
`or heel 46 of blade 14. The grade sensor 39 maintains the toe
`45 of blade 14 at a preselected elevational position relative
`to a grade reference point through control of the correspond-
`ing hydraulic lift cylinder 20 by implement controller 28.
`The heel 46 is assigned to the “slope sensor” mode of
`operation, and its elevation is controlled by the programmed
`cross slope value selected and stored in the implement
`controller 28 that controls the corresponding hydraulic lift
`cylinder 20.
`With reference to FIGS. 2A, 2B and 3, as the operator
`rotates the blade 14 through the “swap position” as deter-
`mined by implement controller 28, the implement controller
`28 automatically changes the “grade sensor” and “slope
`sensor” assignments to the toe 45 and heel 46 of blade 14,
`and the cross slope of the blade 14. Preferably, implement
`controller 28 automatically reverses or “swaps” the “grade
`sensor” and “slope sensor” assignments to the toe 45 and
`heel 46 of blade 14, and the cross slope of the blade 14 to
`configure motor grader 10 to grade in the opposite direction
`as shown in FIG. 2B. During the “automatic” swap, the sides
`of blade 14 may each be assigned to the “manual” mode of
`operation to prevent any unexpected movement of blade 14
`during the “swap”.
`Alternatively, an automatic mode swap switch 49 (FIGS.
`2A and 2B) may be provided in cab 32 to allow the operator
`to automatically rotate the blade 14 to the mirror angular
`position 48 (FIG. 3) by a single manual actuation of the
`switch 49. Depression of the automatic mode swap switch
`49 also automatically changes the “grade sensor” and “slope
`sensor” assignments to the toe 45 and heel 46 of blade 14,
`and the cross slope of blade 14 as described in detail above.
`In this aspect of the invention, the automatic mode swap
`switch 49 is electrically coupled to the implement controller
`28. The circle drive 24 is an electrohydraulic circle drive that
`operates under the control of implement controller 28. The
`set rotational position of blade 14 during a beginning
`grading pass is stored in memory of the implement control-
`ler 28, and is recalled by implement controller 28 to auto-
`matically move blade 14 to the mirror angular position 48
`upon depression of switch 49 to reconfigure the motor
`grader 10 for a return grading pass in the opposite direction.
`
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`US 6,286,606 B1
`
`7
`Industrial Applicability
`
`the
`With reference to the drawings and in operation,
`operator of the work machine 10 selects “manual” or “auto-
`matic” modes of operation for each side of the blade 14 by
`actuating the mode select switches 26 corresponding to each
`side of the blade 14. In either mode, the operator also selects
`“grade sensor”, “down force”, or “slope sensor” control for
`each side of the blade 14 by actuating sensor select switches
`38 corresponding to each side of the blade 14. Control of
`each side of blade 14 is independently assignable to one of
`the “manual” and automatic” modes of operation, and one of
`the “grade sensor”, “down force” and “slope sensor” modes
`as well.
`
`After a grading pass in one direction, the operator rotates
`blade 14 relative to frame 18 to configure the rotation of
`blade 14 for the return pass in the opposite direction. As the
`blade 14 rotates past the predetermined “swap position”, the
`implement controller 28 preferably automatically reverses
`or “swaps” the “grade sensor” (or “down force”) and “slope
`sensor” assignments to the toe 45 and heel 46 of blade 14,
`and the cross slope of the blade 14 to configure motor grader
`10 to grade in the opposite direction.
`Alternatively, the operator manually actuates the auto-
`matic mode swap switch 49 to automatically rotate blade 14
`to the mirror angular position 48, and preferably reverse the
`“grade sensor” (or “down force”) and “slope sensor” assign-
`ments to corresponding sides of the blade 14, and the cross
`slope of blade 14.
`The automatic “swap” performed by implement controller
`28 enhances operator accuracy and efficiency as the blade 14
`is automatically configured for grading in the opposite
`direction.
`
`Other aspects, objects and advantages of the present
`invention can be obtained from a study of the drawings, the
`disclosure and the appended claims.
`What is claimed is:
`
`1. An apparatus for controlling a work implement of a
`work machine in simultaneous first and second control
`
`modes of operation, comprising:
`an implement controller operable to assign the first and
`second control modes of operation to the work imple-
`ment wherein the implement controller is operable to
`reverse the first and second mode assignments to the
`work implement upon receipt of a signal; and
`a sensor associated with the work implement and coupled
`to the implement controller for applying said signal to
`the implement controller indicating position of the
`work implement, whereby the implement controller is
`operable to change the control mode assignments to the
`work implement upon determining a predetermined
`movement of the work implement as indicated by the
`sensor.
`
`2. An apparatus as recited in claim 1, wherein the imple-
`ment controller is operable to detect a predetermined rota-
`tion of the work implement.
`3. An apparatus as recited in claim 1, including a manually
`actuatable device coupled to the implement controller for
`selecting the first and second control mode assignments to
`the work implement.
`4. An apparatus as recited in claim 1, including a sensor
`associated with the work implement and coupled to the
`implement controller for applying signals to the implement
`controller indicating pitch and roll positions of the work
`implement.
`5. A geographic surface altering work machine, compris-
`mg:
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`a moveable machine frame;
`a work implement moveably connected to the machine
`frame; and
`an apparatus for controlling the work implement in simul-
`taneous first and second control modes of operation
`according to claim 1.
`6. An apparatus for controlling opposite sides of a work
`implement of a work machine in simultaneous first and
`second control modes of operation, comprising:
`an implement controller operable to assign the first and
`second control modes of operation to the opposites
`sides of the work implement, wherein one side of the
`work implement is assigned to the first control mode
`and the other side of the work implement is assigned to
`the second control mode; and
`a sensor associated with the work implement and coupled
`to the implement controller for applying a signal to the
`implement controller indicating position of the work
`implement, whereby the implement controller is oper-
`able to change the first and second control mode
`assignments to the opposite sides of the work imple-
`ment upon determining a predetermined movement of
`the work implement as indicated by the sensor.
`7. An apparatus as recited in claim 6, wherein the imple-
`ment controller is operable to detect a predetermined rota-
`tion of the work implement.
`8. An apparatus as recited in claim 6, wherein the imple-
`ment controller is operable to reverse the first and second
`control mode assignments to the opposite sides of the work
`implement upon receipt of the signal from the sensor.
`9. An apparatus as recited in claim 6, including a manually
`actuatable device coupled to the implement controller for
`selecting the first and second control mode assignments to
`the opposite sides of the work implement.
`10. An apparatus as recited in claim 6, including a sensor
`associated with each side of the work implement and
`coupled to the implement controller, wherein each sensor is
`operable to apply a signal
`to the implement controller
`indicating elevational position of the corresponding side of
`the work implement.
`11. An apparatus as recited in claim 6, including a sensor
`associated with the work implement and coupled to the
`implement controller for applying a signal to the implement
`controller indicating slope of the work implement.
`12. An apparatus for controlling oppo