Information
-
Patent Grant
-
6725142
-
Patent Number
6,725,142
-
Date Filed
Tuesday, July 9, 200222 years ago
-
Date Issued
Tuesday, April 20, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Finnegan, Henderson, Farabow, Garrett & Dunner
-
CPC
-
US Classifications
Field of Search
US
- 414 699
- 414 694
- 414 6955
- 414 695
- 414 700
- 414 698
- 701 1
- 701 50
- 701 36
- 172 2
- 172 3
- 172 4
- 172 45
-
International Classifications
-
Abstract
A control system for orienting a swing axis of a work machine is disclosed. The work machine includes a swing frame and a frame structure, and the control system includes an operator interface configured to receive operator inputs, wherein the operator inputs represent a desired orientation of the swing axis of the swing frame. The control system also includes a sensor assembly configured to determine an actual orientation of the swing axis of the swing frame and a controller configured to compare the desired orientation to the actual orientation of the swing axis to determine a swing angle. The controller is adapted to output the swing angle. The swing axis may be adjusted by adjusting the work machine frame or by adjusting a frame assembly independent of the work machine frame.
Description
TECHNICAL FIELD
This invention relates generally to an automatic control system for a work machine. More particularly, the invention relates to an automatic system for orienting a swing axis of the work machine.
BACKGROUND
Excavating type machines, such as a backhoe loader, are versatile machines equipped with a work implement, such as a bucket mechanism, for grading slopes, digging trenches, and performing other excavations. These excavations are often in close proximity to buildings, sidewalks, or buried utilities.
On any ground or terrain, an operator must take care to properly orient the excavating type machine prior to beginning work or the machine will not dig with a clean horizontal surface. For instance, if the excavating type machine were leaning to one side on a flat surface, the bucket would dig in deeper at one corner of the bucket than the other. The ability to dig a vertical face or a ditch with a vertical wall is especially hindered by an out-of-level machine. An out-of-level machine can result in an out-of-level bucket that either digs a ditch with an angled face or creates a somewhat vertical face having jagged edges.
When an excavating type machine, such as a backhoe loader, is used to grade a slope, the backhoe is stationed in position at the top edge of the grade. The boom and bucket extend from the backhoe over the edge of the slope. An operator manipulates the bucket down onto the sloped ground to remove or distribute dirt along the slope. The boom and bucket are pivoted about a swing axis and extended to grade all accessible regions of the slope. During grading, the edge of the bucket maintains a proper roll position of being parallel to the plane of the graded slope only when the boom is pointing either directly down the slope or along the steepest gradient of the slope. If the boom pivots about the swing axis to any direction that is not directly down the slope or along the steepest gradient, the bucket edge will not be parallel to the slope face. As such, when grading or moving dirt, one edge of the bucket will dig in before the other edge, causing ridges in the dirt, instead of the desired flat surface.
Some excavating type machines are equipped with stabilizing arms configured to remove the weight of the machine from the machine tires and to stabilize the machine during the digging operation. These stabilizing arms are also used to level the machine. However, the leveling operation is typically only an approximation and is dependant on the judgment of the machine operator. If the operator's judgment is not good, the excavation may be angled considerably, which may result in damage to adjacent structures or to previously buried cables or pipelines.
One attempt to address the deficiencies described above is disclosed in U.S. Pat. No. 5,288,196 to Sutton, II, issued Feb. 23, 1999. The '196 patent discloses a computer controlled backhoe having a frame with an imaginary roll axis and a pitch axis. Two outriggers are used to level the frame relative to the roll axis with appropriate hydraulic actuators to move the outriggers. The system includes a dual axis gyro, which continuously senses the positions of the roll and pitch axes of the frame. The information is supplied to a computer, which compensates for changes in the frame position. The '196 patent, however, does not provide an automated control system capable of continuously adjusting the swing axis of a work machine digging assembly to a desired orientation.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
SUMMARY OF THE INVENTION
One aspect of the present invention is a control system for orienting a swing axis of a work machine. The work machine includes a swing frame and a frame structure, and the control system includes an operator interface configured to receive operator inputs, wherein the operator inputs represent a desired orientation of the swing axis of the swing frame. The control system also includes a sensor assembly configured to determine an actual orientation of the swing axis of the swing frame and a controller configured to compare the desired orientation to the actual orientation of the swing axis to determine a swing angle. The controller is adapted to output the swing angle.
In another aspect of the invention, a method of orienting a swing axis of a work machine having a swing frame and a frame structure is disclosed. The method includes the steps of entering operator inputs into an operator interface, wherein the operator inputs represent a desired orientation of the swing axis of the swing frame, sensing the actual orientation of the swing axis, comparing the desired orientation to the actual orientation of the swing axis to determine a swing angle, and adjusting the swing axis based on the swing angle to obtain the desired orientation of the swing axis.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and together with the written description, serve to explain the principles of the invention.
FIG. 1
is a diagrammatic side view of an exemplary embodiment of a work machine according to the invention.
FIG. 2
is a rear view of the work machine of
FIG. 1
FIG. 3
is diagrammatic side view of a digging assembly for a work machine showing a swing axis.
FIG. 4
is a flow diagram implementing an exemplary embodiment of the control system of the present invention.
FIG. 5
is a front view of an operator interface of an exemplary embodiment of the present invention.
FIG. 6
is a diagrammatic side view of a second exemplary embodiment of a work machine according to the invention.
FIG. 7
is an enlarged side view of a portion of the second exemplary embodiment of the control system of the present invention shown in dotted lines in FIG.
6
.
FIG. 8
is a front view of the assembly of FIG.
7
.
FIG. 9
is a top view of the assembly of FIG.
7
.
DETAILED DESCRIPTION
Embodiments of the present invention are now described with reference to the figures, where like reference numbers indicate identical or functionally similar elements. Also in the figures, the left most digit of each reference number corresponds to the figure in which the reference number is first used. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention.
With reference to
FIG. 1
, a work machine
100
for performing a variety of work functions includes a frame structure
102
, an operator's compartment
106
supported on frame structure
102
, and a digging assembly
108
, which is supported by frame structure
102
and is typically connected to the rear portion of work machine
100
.
Work machine
100
further includes front wheels
104
and rear wheels
105
for supporting the work machine
100
. Work machine
100
could be of a type commonly referred to as a backhoe loader and may further include a front work implement assembly
130
, such as a loader bucket assembly, which may be connected to frame structure
102
at the front portion of work machine
100
. While the exemplary embodiment is shown as a backhoe loader, other types of work machines may utilize the present invention.
Digging assembly
108
includes a swing frame
110
, a boom member
112
, a stick member
114
, and a work implement
116
. Digging assembly
108
can be used, for example, to dig a hole or ditch, level the ground, or grade an area at a desired angle. Swing frame
110
may be connected to and supported by frame structure
102
. Boom member
112
extends between swing frame
110
and stick member
114
. Stick member
114
extends from boom member
112
to work implement
116
. Work implement
116
is connected to an end of stick member
114
.
Work implement
116
may be, for example, a bucket or shovel for picking up and moving dirt and soil, but may be any other implement, as would be apparent to one skilled in the relevant art. Actuators
118
extend between swing frame
110
and boom member
112
, between boom member
112
and stick member
114
, and between stick member
114
and work implement
116
to operate and manipulate boom member
112
, stick member
114
, and work implement
116
. Actuators
118
are typically hydraulic powered cylinders, but may be other types of actuators as would be apparent to one skilled in the art.
Work machine
100
may include a stabilizing system
120
best seen in FIG.
2
. Stabilizing system
120
of work machine
100
includes first and second stabilizing arms
221
,
222
and respective first and second stabilizing actuators
224
,
226
. Stabilizing actuators may be hydraulic powered cylinders, but may be other types of actuators as would be apparent to one skilled in the art.
Stabilizing arms
221
,
222
extend from frame structure
102
and are adapted to stabilize work machine
100
during a digging operation. Generally, because the tires on work machines are air-filled and compressible, application of large loads, as are applied by digging, lifting, and rotating digging assembly
108
, can rock, bounce or otherwise move work machine
100
during a digging operation. Stabilizing arms
221
,
222
can be used to remove the weight of work machine
100
, as well as the weight of digging assembly
108
and any material carried by the digging assembly from rear wheels
105
, thereby reducing the chance of bouncing or incremental displacement of the work machine. Furthermore, when the work implement carries heavy loads, extension of boom member
112
and stick member
114
provides an increasing cantilever load, which can cause work machine
100
to become unstable. Accordingly, stabilizing arms
221
,
222
may extend beyond the width of rear wheels
105
to provide a wider base for stabilizing work machine
100
.
Front work implement assembly
130
may be used to raise front wheels
104
from the ground, thereby eliminating bouncing of the front end of work machine
100
. When front work implement assembly
130
is lowered in order to remove any load from front wheels
104
and stabilizing actuators
224
,
226
are lowered to remove any load from the rear tires, work machine
100
is stabilized by a tripod-like three point balance system.
Stabilizing actuators
224
,
226
operate by extending or retracting to control the placement of stabilizing arms
221
,
222
. By lengthening stabilizing actuators
224
,
226
, stabilizing arms
221
,
222
are lowered to the ground, and frame structure
102
and rear wheels
105
can be lifted from the ground. By shortening stabilizing actuators
224
,
226
, stabilizing arms
221
,
222
lower frame structure
102
and rear wheels
105
to the ground, and then stabilizing arms
221
,
222
are lifted from the ground.
Stabilizing actuators
224
,
226
may be separately actuated in order to allow individual setting of the stabilizing arms. As such, activating stabilizing actuators
224
,
226
may also serve to tilt the work machine
100
and digging assembly
108
relative to the ground, thereby enabling an operator to orient the work machine at a desired tilt or angle.
Swing frame
110
of digging assembly
108
may rotate toward either side of work machine
100
about a swing axis
228
. Accordingly, because swing frame
110
supports boom member
112
, stick member
114
and work implement
116
, all of digging assembly
108
rotates about swing axis
228
.
A swing axis can be better seen with relation to the separate digging assembly illustrated in FIG.
3
.
FIG. 3
shows an embodiment of a digging assembly
300
including a swing frame
302
, a boom member
304
, a stick member
306
, and a work implement
308
. As shown, swing frame
302
pivots about swing axis
310
.
FIGS. 4 and 5
relate to an exemplary method and system for implementing the control system of the present invention.
FIG. 4
is a flow chart showing an exemplary method of controlling the orientation of a swing axis of a work machine.
FIG. 5
is an exemplary operator interface
500
for the control system. The control system may include a computer control module such as a computer processor with interphase and pre-programmed ROM configured to calculate and output displacement commands to change the orientation of a swing axis of a work machine. The control module may be, for example, any standard central processor in a computer, as would be apparent to one skilled in the relevant art.
The method and control system may be performed and used on a variety of work machines, and for illustrative purposes, will now be described as if being performed and used on work machine
100
. As such, the control system could be used to control the orientation of swing axis
228
of work machine
100
. Operator interface
500
(
FIG. 5
) may be placed within the operator's compartment
106
(in
FIG. 1
) and can be used and referenced by the operator during use of work machine
100
. Operator interface
500
may include a title bar
502
. Title bar
502
could have the title shown, “AutoLevel Operator Interface,” or could have any other title that designates operator interface
500
as the leveling interface. Alternatively, operator interface
500
need not have a title or title bar at all.
In a step
400
of
FIG. 4
, an operator activates the system. An on/off toggle switch, shown at
504
in
FIG. 5
, may be used to turn the system on. If toggle switch
504
is toggled off, or the operator overrides the control system when the system is toggled on, work machine
100
may be leveled or oriented manually as the operator may desire.
In a step
402
, the operator inputs the units that the operator wishes to operate with. The units may be inputted through a roll angle unit selector
506
and a pitch angle unit selector
508
. Roll angle unit selector
506
and pitch angle unit selector
508
allow an operator to select the angle units used to orient swing axis
228
. The units selected by roll angle unit selector
506
and pitch angle unit selector
508
are the units that are displayed to an operator in value displays, as is described further below.
Roll angle unit selector
506
and pitch angle unit selector
508
allow an operator to select units from an option list that may include, for example, degrees, radians and percent grade. Other units may be available as would be apparent to one skilled in the art. An operator may select different unit options using any method, including, for example, a drop down menu showing all the selectable units, a dial, or a menu configured to scroll through the unit choices, displaying one option at a time. It is contemplated that the units may be preset, or the system may be set to default to a particular unit option if the operator makes no selection.
In a step
404
, the operator inputs a desired orientation of the swing axis. The operator may input the desired orientation of the swing axis as desired pitch and roll angles. A roll angle is the deviation of swing axis
228
from a vertical position in a side-to-side direction. Accordingly, roll angle is affected by the settings of the stabilizing arms
221
,
222
. For example, if first stabilizing arm
221
is actuated more than second stabilizing arm
222
, thereby tilting work machine
100
, the angle of tilt of swing axis
228
is the roll angle. A pitch angle is the deviation of swing axis
228
from a vertical position in a front-to-back direction. Accordingly, pitch angle is affected by the settings of the stabilizing arms
221
,
222
in relation to the front of the work machine. As such, if both stabilizing arms
221
,
222
are used to lift the rear of work machine
100
, and the front end is not lifted, the angle of tilt of swing axis
228
in the front-to-back or back-to-front direction is the pitch angle. Likewise, if front work implement assembly
130
is used to lift or lower the front end of the work machine
100
, the pitch angle is affected.
A desired roll angle display
510
and a desired pitch angle display
512
show the desired angle values that are inputted by an operator. The desired roll and pitch angles may be any roll and pitch angles at which the operator desires swing axis
228
to be oriented. The desired roll and pitch angles may be the angles required to orient swing axis
228
in a direction perpendicular to an angled surface, such as a slope to be graded, or may be any other desired angled direction. The desired roll angle and the desired pitch angle may be inputted into the control system using, for example, a numerical keypad, keyboard, mouse, dial, touch screen or any other input device, as would be apparent to one skilled in the relevant art. The control system may be configured to allow the operator to input either the desired angle of the swing axis or the angle of a work surface or desired slope. In the case where an angle of a surface is inputted, the control system may adjust the orientation of the swing axis relative to the inputted surface angle.
The operator may enter a warning threshold at a step
406
. The warning threshold is the amount of allowed deviation of the desired orientation of the swing axis from a measured orientation of the swing axis. The measured orientation of the swing axis is the actual orientation of the swing axis, and is described further below. Operator interface
500
shows a roll angle warning threshold value display
514
and a pitch angle warning threshold value display
516
. The roll and pitch angle warning threshold values set a range of tolerance of swing axis
228
in the roll and pitch directions, respectively.
If either the roll angle warning threshold value or the pitch angle warning threshold value is exceeded, an alarm may be activated to warn the operator of the deviation. The alarm could be either a visual alarm, such as a blinking light, or an audible alarm, such as a beeping alarm, or both, as would be apparent to one skilled in the art. The operator may either correct the orientation of swing axis
228
so that the deviation is within the set range, turn off the alarm and ignore the deviation, or reset the roll angle warning threshold value or the pitch angle warning threshold value at a higher value.
At a step
408
, the operator selects a level mode from a level mode selector display
518
. Level mode selector display
518
allows an operator to select from at least two different level modes. Level mode selector display
518
could be, for example, a drop down menu or a scrolling menu. Alternatively, level mode selector display
518
could continuously display all selectable level modes, thereby enabling an operator to easily determine which level mode is selected and which level modes are not selected. The embodiment shown displays level mode selector display
518
as a drop down menu. When the level mode selector display
518
is selected, drop down menu
520
appears showing selectable level mode indicators. In this embodiment, level mode indicators include a continuous mode indicator
522
and an on command mode indicator
524
. This embodiment of operator interface
500
shows continuous mode indicator
522
as being selected.
When continuous mode is selected, the control module of the control system continuously reads and compares the desired roll and pitch angles to the measured roll and pitch angles, which are further described below. The control module continuously calculates a swing angle, based on the deviation of the measured pitch and roll angles from the desired pitch and roll angles, continuously updating the swing angle data. The swing angle is continuously outputted from the control module to activate actuators that operate to orient the swing axis of the swing frame.
When on command mode is selected, the control module of the control system reads and compares the desired roll and pitch angles of the swing axis to the measured roll and pitch angles of the swing axis, and calculates the swing angle. The control module outputs the swing angle to activate actuators to orient the swing axis to the desired orientation. When the measured orientation is substantially equal to the desired orientation, the control module stops sending swing angle data to the actuators. Accordingly, once the measured orientation of the swing axis is aligned with the desired orientation of the swing axis, the control module no longer operates to orient the swing axis. As such, the control module does not continuously update the orientation of the swing axis, but updates it only upon the operator's command.
Assuming the operator selected on command mode at step
408
, a measuring device reads the actual, measured orientation of the swing axis at a step
410
. This measured orientation could be read as a measured pitch angle and a measured roll angle. The measured roll angle is displayed in a measured roll angle display
526
, and a measured pitch angle is displayed in a measured pitch angle display
528
on operator interface
500
. The measured roll angle and the measured pitch angle represent the actual orientation of the swing axis of the work machine. The measured roll angle and the measured pitch angle may be measured by a mechanism, such as, for example, a dual-axis inclinometer or a gyroscope. However, any other appropriate measurement mechanism could be used, as would be apparent to one skilled in the relevant art. The angles may be converted to a digital form and outputted to operator interface
500
for display in measured roll angle display
526
and measured pitch angle display
528
.
In the embodiment of
FIGS. 1 and 2
, wherein the swing frame
110
is connected to the frame structure
102
, the measurement mechanism could be secured onto work machine
100
itself. In such an embodiment, the measured roll angle and measured pitch angle of work machine
100
will correspond to the roll angle and the pitch angle of swing axis
228
. In an embodiment where the swing axis is rotatable independent of the orientation of the frame structure of the work machine, such as is described further below with reference to
FIGS. 6-9
, the measurement mechanism should be secured onto structure having a roll angle and a pitch angle that will correspond to the roll angle and the pitch angle of the swing axis, such as, for example, the swing frame of the digging assembly.
The measured pitch angle and the measured roll angle may also be shown in an analog form by analog roll angle indicator
530
and analog pitch angle indicator
532
. In one embodiment, the measured roll angle display
526
, measured pitch angle display
528
, analog roll angle indicator
530
, and analog pitch angle indicator
532
are all updated in real time. In another embodiment, the displays and indicators are updated only at intervals.
At a step
412
, the control module determines whether the measured orientation of the swing axis deviates from the desired orientation by an amount exceeding the warning threshold amount. If the measured orientation of the swing axis does not deviate from the desired orientation by an amount exceeding the warning threshold amount, then the control module takes no corrective action, ending the control at a step
414
.
In one exemplary embodiment, the control system may continue to monitor the deviation of the measured orientation of the swing axis from the desired orientation, and may activate the alarm when the deviation amount exceeds the warning threshold amount. Even then, the control module will not take corrective action when in on command mode.
If at step
412
, the measured orientation of the swing axis does deviate from the desired orientation by an amount exceeding the warning threshold amount, then the control module generates a signal as a swing angle and sends the signal to actuators to adjust the actual pitch and roll angle of the swing axis, as at step
416
. Accordingly, the measured orientation will be changed by the control module.
In one exemplary embodiment, the measured orientation is changed when the control module of the control system outputs the swing angle as a command or commands to actuators disposed on stabilizing arms. The actuators are activated by the commands to move the stabilizing arms to alter the actual orientation of the work machine so that it aligns with the desired orientation of the swing axis by an amount less than the warning threshold. The command or commands may also be provided to the actuators controlling the front work implement assembly.
The actuators may also include hydraulic cylinder controllers that are configured to receive the swing angle signal from the control module and output control signals based on the swing angle signal. Furthermore, the actuators may include cylinder displacement transducers, disposed on the stabilizing arms and/or the front work implement assembly, configured to send measurement signals to the control module. The cylinder displacement transducers may measure the actuator movement that displaces the stabilizing arms and/or the front work implement assembly.
The transducers may alternatively be angle transducers disposed on pivot points on the stabilizing arms and the front work implement assembly. The angle transducers may be configured to send measurement signals to the control module. The transducers may be linear, rotary or any other transducer type. Appropriate transducers may be obtained from, for example, MTS System Corp., of Eden Prairie, Minn.
After or during the time that the actual, and thus the measured, pitch and roll angle of the swing axis are adjusted at step
416
, the measuring device takes new measurements of the adjusted pitch and roll values, at step
410
. The control system continues to loop through steps
410
,
412
and
416
until the measured orientation does not deviate from the desired orientation by an amount exceeding the warning threshold amount. The control system may then end at step
414
.
If the operator selects continuous mode at step
408
, the control system reads an actual, measured orientation of the swing axis, at a step
418
. This measured orientation could be read as a measured pitch angle and a measured roll angle as described above.
At a step
420
, the control module determines whether the measured orientation of the swing axis deviates from the desired orientation by an amount exceeding the warning threshold amount. If the measured orientation of the swing axis does not deviate from the desired orientation by an amount exceeding the warning threshold amount, then the control module takes no corrective action at that time. If at step
420
, the measured orientation of the swing axis does deviate from the desired orientation by an amount exceeding the warning threshold amount, then the control module generates a signal as a swing angle and sends the signal to actuators to adjust the actual pitch and roll angles of the swing axis, as shown at a step
422
. Accordingly, the measured orientation will be changed by the control system by sending signals as described above with reference to the on command mode.
When in continuous mode, the control module reads and calculates the swing angle in real time, continuously updating the swing angle data. The swing angle is the angle of correction required to align the measured angles to the desired angles. Depending on the system used, the swing angle may not be an actual angle, but may merely represent correction data that would align the measured swing axis orientation to the desired swing axis orientation. The swing angle is outputted from the control module to activate actuators that operate to orient swing axis
228
of the swing frame
110
.
Whether or not the measured orientation deviates from the desired orientation by an amount exceeding the established threshold at step
420
, and after or during the time that the actual, and thus the measured, pitch and roll angles of the swing axis are adjusted at step
422
, the automatic control system can be disrupted by a number of deactivating events. If any one of the deactivating events occur, the control system is disabled, and the work machine returns to full manual control. Accordingly, the automatic control may continue until the conditions for disruption override the automatic control at any time, ending the automatic control. At a step
424
, the control system confirms that no overriding events have occurred regardless of step
420
. As would be obvious to one skilled in the art, the system need not positively confirm that any of the overriding events have occurred, but will proceed with automatic control until one of the overriding events do occur. Examples of overriding events include switching the control system to off, changing the selected level mode, manually operating the controls of the controlled actuators, placing the machine in gear, and powering off the machine. If any overriding event has occurred, the control system ends control at a step
426
.
If any deactivating events have not occurred, then the system returns from step
424
to step
418
, and the control module determines the measured orientation of the swing axis. The control system will continue to loop when in continuous mode until an overriding event occurs.
In one exemplary embodiment, the control module of the control system does not activate the actuators to adjust the swing angle until after the warning threshold value is exceeded. Therefore, corrective action is taken at less frequent intervals than when the control system corrects for any deviation of the measured orientation from the desired orientation. In another exemplary embodiment, a preprogrammed activation threshold is included in the control system, thereby allowing activation only when the orientation of swing axis
228
deviates from the desired orientation by a minimum amount, such as, for example 0.25 degrees.
In one exemplary embodiment, operator interface
500
includes a deviation value display (not shown). The deviation value display shows the difference of the measured orientation from the desired orientation. More specifically, the deviation value display shows the difference between the measured roll angle from the desired roll angle and the measured pitch angle from the desired pitch angle.
A second exemplary structural embodiment for orienting a swing axis is described with reference to
FIGS. 6-9
. The second exemplary embodiment includes a frame assembly that allows the swing axis to be oriented independent of the orientation of the frame of the work machine. In the second exemplary embodiment, the swing axis is adjusted using actuators in a pitch and roll frame assembly. The method and system described with reference to
FIGS. 4 and 5
may be similarly applied to automatically orient the swing axis of the second exemplary embodiment.
With reference to
FIG. 6
, a work machine
600
includes a frame structure
602
, an operator's compartment
604
, and a digging assembly
606
disposed at the rear of the work machine
600
. Work machine
600
includes front wheels
608
and rear wheels
610
and may further include a front work implement assembly
612
.
Digging assembly
606
includes a swing frame
614
, a boom member
616
, a stick member
618
, and a work implement
620
, and may operate using actuators configured as is known in the art. Work machine
600
may also include a stabilizing system
621
including stabilizing arms, similar to that described with reference to FIG.
1
.
A multi-degree-of freedom frame assembly
624
may be disposed at the rear of work machine
600
between frame structure
602
and digging assembly
606
. Frame assembly
624
is shown circled in dashed lines in FIG.
6
. Frame assembly
624
allows a swing axis
622
to have rotational ability in the pitch direction and the roll direction independent of the work machine frame. As stated above, this orientation may be accomplished through the exemplary control system described in connection with
FIGS. 4 and 5
.
Frame assembly
624
is described in greater detail with reference to
FIGS. 7-9
. As shown in
FIG. 7
, frame assembly
624
includes swing frame
614
pivotally connected to a roll frame
706
. Swing frame
614
may be part of a digging assembly, as described with reference to
FIGS. 1-3
. Swing frame
614
pivots about swing axis
622
. Roll frame
706
is rotatably connected to a pitch frame
708
. Pitch frame
708
is supported by or connected to frame structure
602
of a work machine.
Swing frame
614
includes a top swing arm
712
and a bottom swing arm
714
extending from a main body
716
. Top and bottom swing arms
712
,
714
each include through holes, which are aligned and formed to fit top and bottom swing pins
718
,
719
about which swing frame
614
may rotate.
Roll frame
706
may be, generally, a C-shaped frame structure having a top portion
720
, a bottom portion
722
, a closed side
724
, and an open side
726
. Open side
726
is configured to receive top and bottom swing arms
712
,
714
of swing frame
614
. Roll frame
706
includes openings for receiving and securing swing pins
718
,
719
. Accordingly, swing frame
614
may rotate about swing axis
622
when connected to roll frame
706
. Roll frame
706
may include a connection bar support
728
for securing top swing arm
712
into roll frame
706
. Connection bar support
728
may be a right-angled support that extends from top portion
720
of roll frame
706
toward open side
726
of roll frame
706
. Top swing arm
712
of swing frame
614
fits between top portion
720
of roll frame
706
and connection bar support
728
. Top swing pin
718
extends from top portion
720
of roll frame
706
, through top swing arm
712
, and into connection bar support
728
of roll frame
706
, securely attaching swing frame
614
to roll frame
706
.
Bottom portion
722
of roll frame
706
includes an opening for receiving bottom swing pin
719
, thereby aligning the opening in bottom portion
722
of roll frame
706
with the through hole in the bottom swing arm
714
, securely attaching bottom swing arm
714
of swing frame
614
to roll frame
706
.
Actuators
730
, best seen in
FIGS. 7 and 9
, extend from closed side
724
of roll frame
706
to swing frame
614
. Actuators
730
control the rotation of swing frame
614
about swing axis
622
. In this exemplary embodiment, two actuators are used to control the rotation of swing frame
614
about swing axis
622
. However, more or less than two actuators could be used, as would be apparent to one skilled in the relevant art.
Roll frame
706
is rotatably connected to pitch frame
208
through a connecting structure, such as, for example, roll pins
732
. Roll pins
732
form a roll axis
734
, about which roll frame
706
may rotate. The connecting structure could be any structure that connects the roll frame to the pitch frame and that allows roll frame
706
to rotate about roll axis
734
.
Pitch frame
708
is a three-sided structure open at the top, as oriented in FIG.
7
. The bottom portion
722
of roll frame
706
fits within the open top of pitch frame
708
, as seen in FIG.
7
. Pitch frame
708
includes a bottom section
736
, a first wall
738
disposed on the side adjacent to swing frame
614
, and a second wall
740
adjacent to closed side
724
of roll frame
706
. First wall
738
and second wall
740
cooperate with roll pins
732
to support roll frame
706
.
Pitch frame
708
is connected to frame structure
602
by a connecting structure, such as, for example, pitch pins
742
. Pitch pins
742
form a pitch axis
846
about which pitch frame
708
may rotate. The connecting structure could be any structure that connects the pitch frame
708
to the frame structure
602
and that allows pitch frame
708
to rotate about pitch axis
846
.
Bottom section
736
of pitch frame
708
includes an extension
848
that extends beyond the width of roll frame
706
(best seen in FIG.
9
). Extension
848
is used to support a roll actuator
750
. Roll actuator
750
extends from closed side
724
of roll frame
706
to extension
848
of pitch frame
708
, in a direction perpendicular to, but not crossing, roll axis
734
. Roll actuator
750
controls the rotation of roll frame
706
about roll axis
734
. Accordingly, to orient swing axis
622
in a roll direction, roll actuator
750
is activated to rotate roll frame
706
about roll axis
734
, thereby rotating swing axis
622
, which is fixed to roll frame
706
, in the roll direction.
Likewise, a pitch actuator
752
controls the rotation of pitch frame
708
about pitch axis
846
. Pitch actuator
752
extends from second wall
740
of pitch frame
708
to frame structure
602
in a direction perpendicular to, but not crossing, pitch axis
846
. Accordingly, to rotate swing axis
622
in a pitch direction, pitch actuator
752
is activated to rotate pitch frame
708
about pitch axis
846
, thereby rotating roll frame
706
, swing frame
614
, and swing axis
622
in the pitch direction.
Various alternative embodiments to the exemplary structure of frame assembly
624
are contemplated. For example, in one exemplary embodiment, the swing frame may be directly connected to the pitch frame and the roll frame may be directly connected to the machine frame structure. In another exemplary embodiment, the pitch actuator and/or the roll actuator may be connected to the digging assembly.
The control system described with reference to
FIGS. 4 and 5
may be used with the pitch and roll frames described above. In this embodiment, the control module of the control system compares an inputted desired orientation of the swing axis to a measured orientation of the swing axis and calculates a swing angle, as described with reference to
FIGS. 4 and 5
. The measuring device is disposed on structure of the work machine that will correspond to the swing axis, such as the swing frame. The swing angle may be outputted from the control module to activate the pitch and roll actuators of the frame assembly
624
to orient the swing axis
622
to the desired orientation.
Industrial Applicability
When digging or grading with a work machine having a work implement, it is often useful to control the orientation of the swing axis of the work implement and its associated digging assembly. For instance, by orienting the swing axis in a direction perpendicular to a desired grading surface, the digging edge of the work implement is parallel to the plane of the digging surface through the swinging range of the digging assembly. Therefore, a planar working surface may be obtained when grading, and saw-tooth ridges of material are avoided. Furthermore, orienting the swing axis in a direction perpendicular to a desired surface when digging a trench results in a trench having smooth walls, rather than jagged walls.
The present invention is an automatic control system that allows an operator to input a desired orientation of the swing axis of a work machine. The system then automatically orients the swing axis to the desired orientation. The control system may be implemented to adjust the orientation of the work machine frame if the swing axis of the digging assembly is dependent upon the machine frame orientation. Such a work machine is shown in the
FIG. 1
embodiment. Alternatively, the control system may be implemented to adjust the orientation of a swing axis independent of the machine frame. An exemplary embodiment of this implementation is shown in FIG.
6
.
The control system enables an operator to easily align the swing axis perpendicular to a slope or at any other desirable orientation. The ease with which an operator may set and orient the swing axis position increases operator efficiency because the operator is not required to manually adjust the settings by trial and error.
Additionally, over the course of a digging project, the movements of the digging assembly may slightly displace the work machine, such that the initial angle setting of the swing axis may not be maintained. The control system enables an operator to maintain the desired swing axis angle without constantly manually adjusting the angle. As such, the system is particularly advantageous for inexperienced operators or fatigued operators, who may not be constantly aware of the orientation of the swing axis. As an additional precaution, the present invention notifies an operator if the angle of the swing axis begins to change from its initially set orientation.
The present invention is adaptable to a variety of work machines where maintaining a swing axis at a specific orientation (e.g. perpendicular to a work surface) may be desirable. For instance, the present invention may be useful on excavators, front shovels, material handlers, or any work machine having a swing axis about which a work implement rotates.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Claims
- 1. A control system for orienting a swing axis of a work machine having a swing frame and a frame structure, the system comprising:an operator interface configured to receive operator inputs, wherein the operator inputs represent a desired orientation of the swing axis of the swing frame; a sensor assembly configured to determine an actual orientation of the swing axis of the swing frame; and a controller configured to compare the desired orientation to the actual orientation of the swing axis to determine a swing angle, the controller being adapted to output the swing angle.
- 2. The control system of claim 1, wherein the desired orientation of the swing axis is based on a desired pitch angle and a desired roll angle.
- 3. The control system of claim 1, further including a pair of stabilizing arms that are actuated according to the swing angle, wherein the stabilizing arms alter the orientation of the work machine to orient the swing axis in the desired orientation.
- 4. The control system of claim 3, further including:cylinder displacement transducers disposed on the pair of stabilizing arms, wherein the cylinder displacement transducers are configured to send a measurement signal to the controller indicative of the position of the pair of stabilizing arms; and a hydraulic cylinder controller configured to receive the swing angle from the controller and adjust the position of the pair of stabilizing arms.
- 5. The control system of claim 3, further including:angle transducers disposed at pivot points on the pair of stabilizing arms, wherein the angle transducers are configured to send a measurement signal to the controller indicative of the position of the pair of stabilizing arms; and a hydraulic cylinder controller configured to receive the swing angle from the controller and adjust the position of the pair of stabilizing arms.
- 6. The control system of claim 1, wherein the operator interface includes a display configured to show the actual orientation as a measured roll angle and a measured pitch angle, and configured to show the desired orientation as a desired roll angle and a desired pitch angle.
- 7. The control system of claim 1, further including an alarm for warning an operator when the actual orientation deviates from the desired orientation by a set amount.
- 8. The control system of claim 1, further including:a roll frame; a pitch frame connected to the roll frame, wherein the roll frame and the pitch frame are disposed between the frame structure and the swing frame, such that the swing axis of the swing frame rotates independent of the work machine frame structure in a pitch direction and in a roll direction; a first actuator disposed between the pitch frame and the roll frame; and a second actuator disposed between the machine frame structure and the pitch frame, wherein the first and second actuators are configured to move the roll and pitch frames, respectively, based on the swing angle.
- 9. A method of orienting a swing axis of a work machine having a swing frame and a frame structure, the method comprising:entering operator inputs into an operator interface, wherein the operator inputs represent a desired orientation of the swing axis of the swing frame; sensing the actual orientation of the swing axis; comparing the desired orientation to the actual orientation of the swing axis to determine a swing angle; and adjusting the swing axis based on the swing angle to obtain the desired orientation of the swing axis.
- 10. The method of claim 9, wherein adjusting the swing axis includes adjusting the orientation of the frame structure of the work machine.
- 11. The method of claim 10, wherein adjusting the swing axis includes activating a pair of stabilizing arms based on the swing angle, the pair of stabilizing arms being connected to the frame structure such that the frame structure is displaced by the stabilizing arms to orient the swing axis to the desired orientation.
- 12. The method of claim 9, wherein the operator inputs include a desired roll angle and a desired pitch angle.
- 13. The method of claim 9, wherein the operator inputs include a desired roll angle and a desired pitch angle, and the actual orientation includes a sensed roll angle and a sensed pitch angle,wherein the sensed roll angle and the sensed pitch angle are updated in real time to reflect changes in the sensed roll angle or the sensed pitch angle.
- 14. The method of claim 9, wherein adjusting the swing axis includes adjusting the orientation of the swing frame independent of the frame structure of the work machine.
- 15. The method of claim 14, further including:activating a first actuator based on the swing angle to move the swing axis of the swing frame in a roll direction, wherein the swing axis of the swing frame moves independent of the frame structure in the roll direction; and activating a second actuator based on the swing angle to move the swing axis of the swing frame in a pitch direction, wherein the swing axis of the swing frame moves independent of the frame structure in the pitch direction.
- 16. The method of claim 15, wherein the desired orientation of the swing axis is a direction substantially perpendicular to a work surface.
- 17. The method of claim 15, wherein the first actuator extends from a roll frame to a pitch frame, and the second actuator extends from the pitch frame to the frame structure.
- 18. A control system for orienting a swing axis of a work machine having a swing frame and a frame structure, the system comprising:an operator interface configured to receive operator inputs, wherein the operator inputs represent a desired orientation of the swing axis; a device configured to determine a measured orientation of the swing axis; a control module configured to compare the desired orientation to the measured orientation of the swing axis to determine a swing angle, the control module being adapted to output the swing angle; and actuators that are actuated according to the swing angle, wherein the actuators are configured to adjust the work machine frame to thereby orient the swing axis to the desired orientation.
- 19. The control system of claim 18, wherein the operator inputs include a desired pitch angle and a desired roll angle, and the desired pitch angle and the desired roll angle are angles that orient the swing axis in direction substantially perpendicular to a work surface.
- 20. The control system of claim 18, further including:a pair of stabilizer arms configured to be operated by the actuators; cylinder displacement transducers disposed on the pair of stabilizer arms, wherein the cylinder displacement transducers are configured to send measurement signals to the control module indicative of the position of the stabilizer arms; and an actuator controller configured to receive the swing angle from the control module and adjust the position of the stabilizer arms.
- 21. The control system of claim 18, further including:a pair of stabilizer arms configured to be operated by the actuators; angle transducers disposed at pivot points on a pair of stabilizers, wherein the angle transducers are configured to send measurement signals to the control module indicative of the position of the stabilizer arms; and an actuator controller configured to receive the swing angle from the control module and adjust the position of the stabilizer arms.
- 22. The control system of claim 18, wherein the operator interface includes a display configured to show the measured orientation as a measured roll angle and a measured pitch angle, and configured to show the desired orientation as a desired roll angle and a desired pitch angle.
- 23. The control system of claim 18, further including an alarm configured to warn an operator when the measured orientation deviates from the desired orientation by a set amount.
- 24. A method of orienting a swing axis of a work machine having a swing frame and a frame structure, the method comprising:receiving operator inputs in an operator interface, wherein the operator inputs represent a desired orientation of the swing axis; determining a measured orientation of the swing axis; comparing the desired orientation to the measured orientation of the swing axis to determine a swing angle; outputting the swing angle; and activating actuators according to the swing angle, wherein the actuators adjust the work machine frame to thereby orient the swing axis to the desired orientation.
- 25. The method of claim 24, wherein receiving operator inputs includes receiving a desired pitch angle and a desired roll angle, and the desired pitch angle and the desired roll angle are angles that orient the swing axis in direction substantially perpendicular to a work surface.
- 26. The method of claim 24, further including:receiving measurement signals from cylinder displacement transducers disposed on the actuators; and sending the swing angle to an actuator controller to adjust the actuators.
- 27. The method of claim 24, further including:displaying the measured orientation of the swing axis as a measured roll angle and a measured pitch angle; and displaying the desired orientation of the swing axis as a desired roll angle and a desired pitch angle.
- 28. The method of claim 24, further including updating the measured orientation in real time.
- 29. A control system for orienting a swing axis of a work machine having a machine frame structure, a swing frame, and a frame assembly connecting the machine frame structure to the swing frame, the system comprising:an operator interface configured to receive operator inputs, wherein the operator inputs represent a desired orientation of the swing axis; a device configured to determine a measured orientation of the swing axis; a control module configured to compare the desired orientation to the measured orientation of the swing axis to determine a swing angle, the control module being adapted to output the swing angle; and actuators that are actuated according to the swing angle, wherein the actuators are configured to adjust the frame assembly independent of the machine frame structure to thereby orient the swing axis to the desired orientation.
- 30. The control system of claim 29, wherein the frame assembly includes:a roll frame connected to the swing frame; and a pitch frame connected to the roll frame and the machine frame structure such that the swing axis of the swing frame rotates in a pitch direction and in a roll direction.
- 31. The control system of claim 30, further including:first and second actuators configured to move the roll and pitch frames respectively, based on the swing angle.
- 32. The control system of claim 31, wherein the first actuator is disposed between the pitch frame and the roll frame, and the second actuator is disposed between the machine frame structure and the pitch frame.
- 33. A method of orienting a swing axis of a work machine having a machine frame structure, a swing frame, and a frame assembly connecting the machine frame structure to the swing frame, the method comprising:receiving operator inputs in an operator interface, wherein the operator inputs represent a desired orientation of the swing axis; determining a measured orientation of the swing axis; comparing the desired orientation to the measured orientation of the swing axis to determine a swing angle; outputting the swing angle; and activating actuators according to the swing angle, wherein the actuators adjust the frame assembly independent of the machine frame structure to thereby orient the swing axis to the desired orientation.
- 34. The method of claim 33, wherein activating actuators includes:activating a first actuator to move the swing axis of the swing frame in a roll direction; and activating a second actuator to move the swing axis of the swing frame in a pitch direction.
- 35. The method of claim 34, wherein the first actuator extends from a roll frame to a pitch frame, and the second actuator extends from the pitch frame to the machine frame structure.
US Referenced Citations (23)