U.S. patent application number 15/077008 was filed with the patent office on 2017-09-28 for control system for a machine.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Thuong Dao Anh Le, Jeffrey Kent Berry, Matthew Stephen Marquette, Brad Robert Van De Veer.
Application Number | 20170275848 15/077008 |
Document ID | / |
Family ID | 59897792 |
Filed Date | 2017-09-28 |
United States Patent
Application |
20170275848 |
Kind Code |
A1 |
Marquette; Matthew Stephen ;
et al. |
September 28, 2017 |
CONTROL SYSTEM FOR A MACHINE
Abstract
A control system for a machine having a linkage, a work
implement mounted on the linkage, and at least one actuator is
provided. The actuator is connected to the linkage and controlled
using the control system to move the linkage and the work
implement. The control system includes sensors that are configured
to sense a current load and position of the work implement. Upon
sensing the current load and position of the work implement, a
controller provided in the control system can reject or accept a
given kick-out command issued from one or more user controls of the
control system based on various criteria associated with the sensed
load and position of the work implement.
Inventors: |
Marquette; Matthew Stephen;
(Peoria, IL) ; Berry; Jeffrey Kent; (Yorkville,
IL) ; Van De Veer; Brad Robert; (Washington, IL)
; Anh Le; Thuong Dao; (Edwards, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
59897792 |
Appl. No.: |
15/077008 |
Filed: |
March 22, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 3/34 20130101; E02F
3/434 20130101; E02F 9/2041 20130101; E02F 3/431 20130101; E02F
9/2004 20130101; E02F 9/265 20130101 |
International
Class: |
E02F 3/43 20060101
E02F003/43; E02F 9/26 20060101 E02F009/26; E02F 9/20 20060101
E02F009/20 |
Claims
1. A control system for a machine having a linkage, a work
implement mounted on the linkage, and an actuator, the actuator
being connected to the linkage and controlled using the control
system to move the linkage and the work implement, the control
system comprising: a plurality of sensors configured to generate
load data indicative of a sensed load of the work implement and
position data indicative of a sensed position of the work
implement; user controls for sending user commands and a kick-out
command, the user controls including at least one primary control,
the primary control being configured to send at least the user
commands; and a controller communicably coupled to the plurality of
sensors and to the user controls and configured to: receive the
user commands and the kick-out command from the user controls,
receive the load data and the position data from the plurality of
sensors, responsive to receiving the user commands from the primary
control, move the work implement to a position defined by the user
commands from the primary control, responsive to the kick-out
command from the user controls, move the work implement to a
predefined kick-out position, determine a work implement load state
based on the load data, and accept or reject the kick-out command
based on at least the work implement load state.
2. The control system of claim 1, wherein the kick-out command
comprises a lower kick-out command to lower the work implement to a
predefined lowered position, and the controller is further
configured to reject the lower kick-out command if the work
implement load state indicates that the work implement is
substantially loaded.
3. The control system of claim 2, wherein the work implement is
pivotable between an upwardly open position and a downwardly open
position, and the controller is further configured to reject the
lower kick-out command if the work implement is in the downwardly
open position.
4. The control system of claim 1, wherein the controller is further
configured to accept or reject the kick-out command based on at
least the work implement load state and the position data.
5. The control system of claim 1, wherein the work implement is
pivotable to define an angular position of the work implement in a
range of movement between an upwardly open position and a
downwardly open position, and the controller is further configured
to accept or reject the kick-out command based on at least the work
implement load state and the position data indicating the sensed
angular position of the work implement.
6. A method of controlling a machine having a controller, a work
implement mounted on a linkage, an actuator connected to the
linkage and operable using the controller to move the work
implement, a plurality of sensors, and user controls for sending
user commands and a kick-out command to the controller, the user
controls including at least one primary control for sending at
least the user commands, the controller being communicably coupled
to the sensors and to the user controls, the method comprising:
sending, to the controller from the plurality of sensors, load data
indicative of a sensed load of the work implement and position data
indicative of a sensed position of the work implement; sending,
from the primary control to the controller, the user commands;
responsive to the user commands from the primary control,
operating, using the controller, the actuator to move the work
implement to a position defined by the user commands from the
primary control; sending, from the user controls to the controller,
the kick-out command; determining, using the controller, a work
implement load state based on the load data; accepting or
rejecting, using the controller, the kick-out command from the user
controls, based on at least the work implement load state; and
responsive to accepting, using the controller, the kick-out command
from the user controls, operating, using the controller, the
actuator to move the work implement to a predefined kick-out
position.
7. The method of claim 6, wherein the kick-out command comprises a
lower kick-out command to lower the work implement to a predefined
lowered position, and further comprising rejecting, using the
controller, the lower kick-out command if the work implement load
state indicates that the work implement is substantially
loaded.
8. The method of claim 6, wherein the work implement is pivotable
between an upwardly open position and a downwardly open position,
and further comprising rejecting, using the controller, the lower
kick-out command if the work implement is in the downwardly open
position.
Description
TECHNICAL FIELD
[0001] The present disclosure generally relates to a control system
for a machine. More specifically, the present disclosure relates to
a control system for selectively overriding accidental input
commands that could cause the machine to inadvertently execute one
or more operations.
BACKGROUND
[0002] It is known in the art to provide means whereby the operator
of a machine such as a wheel loader may command a bucket of the
wheel loader to move automatically and rapidly to a predefined
position. Such a motion or command is referred to by the term
"kick-out" because conventionally it has been implemented by moving
a primary control, typically an operating lever or joystick, to an
extreme position in which it is retained by a detent. The term
"kick-out" reflects the action of the detent which automatically
releases the joystick so that it kicks out of the extreme position
and returns rapidly by resilient bias to the neutral position when
the bucket reaches the predefined position (the "kick-out
position"). A kick-out command allows the operator to move the
bucket to a position in which it is ready for the next operation
without having to provide a continuous input signal via the primary
control, so making it easier to perform a series of repeated
movements, for example, when scooping loose material from a pile
and dumping it into a truck.
[0003] More recently, it has been known to provide separate
kick-out controls such as momentary contact switches whereby the
machine operator can issue a kick-out command without having to
move the joystick or other operating levers to a kick-out position.
U.S. Pat. No. 6,371,214 discloses a control system using which the
kick-out command from the kick-out controls are selectively
implemented depending on the position of the operating levers and
on the previous movements of the machine. That indicates whether or
not the operator has returned the operating levers to a position in
which the bucket can be lowered, for example, after dumping the
load into a truck. The term "kick-out" is still used for such
controls and commands which cause the bucket to move to a
predefined position, even where the detent action which gave rise
to the term is no longer a feature of their operation.
[0004] However, as wheel loaders and like machines are typically
operated in a rapidly changing and unpredictable environment, a
user control may be operated accidentally or unintentionally.
SUMMARY OF THE DISCLOSURE
[0005] In one aspect of the present disclosure, a control system is
provided for a machine having a linkage, and a work implement
mounted on the linkage. The machine also includes at least one
actuator connected to the linkage and controlled by the control
system to move the linkage and the work implement. The control
system includes a plurality of sensors that are configured to
generate load data indicative of a sensed load of the work
implement and position data indicative of a sensed position of the
work implement. The control system further includes user controls
for sending user commands and at least one kick-out command
therefrom. The user controls include at least one primary control
that is configured to send at least the user commands.
[0006] The control system also includes a controller that is
communicably coupled to the sensors and the user controls. The
controller is configured to receive the user commands and the
kick-out command from the user controls; receive the load data and
the position data from the plurality of sensors; move the work
implement to a position defined by the user command from the
primary control in response to receiving a user command from the
primary control; move the work implement to a predefined kick-out
position in response to the kick-out command from the user
controls. Moreover, the controller is also configured to determine
a work implement load state based on the load data, and accept or
reject the kick-out command based on at least the work implement
load state.
[0007] In another aspect of the present disclosure, a machine
includes a linkage, a bucket mounted on the linkage, at least one
actuator connected to the linkage; and the control system of the
present disclosure for controlling the actuator to move the linkage
and the bucket.
[0008] In yet another aspect of the present disclosure, a method is
provided for controlling a machine having a controller, a work
implement mounted on a linkage, at least one actuator connected to
the linkage and operable by the controller to move the work
implement, a plurality of sensors, and user controls for sending
user commands and at least one kick-out command to the controller,
the user controls including at least one primary control for
sending at least the user commands, the controller being
communicably coupled to the sensors and to the user controls. The
method includes sending, to the controller from the plurality of
sensors, load data indicative of a sensed load of the work
implement and position data indicative of a sensed position of the
work implement.
[0009] The method further includes sending, from the primary
control to the controller, a user command; and responsive to the
user command from the primary control, operating, by the
controller, the actuator to move the work implement to a position
defined by the user command from the primary control. The method
also includes sending, from the user controls to the controller, a
kick-out command.
[0010] The method also includes determining, by the controller
based on the load data, a work implement load state; and accepting
or rejecting, by the controller based on at least the work
implement load state, the kick-out command from the user controls.
The method further includes operating, by the controller, the
actuator to move the work implement to a predefined kick-out
position in response to accepting, by the controller, the kick-out
command from the user controls.
[0011] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The features and advantages of the present disclosure will
become more apparent from the detailed description set forth below
when taken in conjunction with the drawings, in which like
reference numbers indicate identical or functionally similar
elements. Additionally, the left-most digit of a reference number
identifies the drawing in which the reference number first
appears.
[0013] FIG. 1 is a side view of an exemplary machine having a work
implement in accordance with embodiments of the present
disclosure;
[0014] FIG. 2 is the exemplary machine of FIG. 1, showing a raised
and upwardly tilted position of the work implement, in accordance
with an embodiment of the present disclosure;
[0015] FIG. 3 is the exemplary machine of FIG. 1, showing a raised
and downwardly tilted position of the work implement, in accordance
with an embodiment of the present disclosure;
[0016] FIG. 4 is the exemplary machine of FIG. 1, showing a lowered
and forwardly-open position (a ready-to-dig position) of the work
implement, in accordance with an embodiment of the present
disclosure;
[0017] FIG. 5 is a top perspective view of user controls that can
be used to control an operation of the work implement in accordance
with embodiments of the present disclosure;
[0018] FIG. 6 is a side perspective view of user controls from FIG.
5 in accordance with embodiments of the present disclosure;
[0019] FIG. 7 is a schematic of a control system that can be
employed in conjunction with the user controls of the machine of
FIG. 1 for overriding accidental actuations of the user controls
and preventing unintended operations of the work implement in
accordance with embodiments of the present disclosure; and
[0020] FIG. 8 is a flowchart depicting a method of controlling the
machine of FIG. 1 in accordance with an embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0021] The detailed description of exemplary embodiments of the
disclosure herein makes reference to the accompanying drawings and
figures, which show the exemplary embodiments by way of
illustration only. While these exemplary embodiments are described
in sufficient detail to enable those skilled in the art to practice
the disclosure, it should be understood that other embodiments may
be realized and that logical and mechanical changes may be made
without departing from the spirit and scope of the disclosure. It
will be apparent to a person skilled in the pertinent art that this
disclosure can also be employed in a variety of other applications.
Thus, the detailed description herein is presented for purposes of
illustration only and not of limitation.
[0022] With reference to FIG. 1, an exemplary machine 100 is
depicted. As shown in FIG. 1, the machine 100 comprises a Wheel
Loader (WL), which is located on a job site 102. The machine 100
may be used in a variety of applications including mining,
quarrying, road construction, construction site preparation, etc.
For example, the WL shown in FIG. 1 may be employed for hauling
earth materials such as ore, soil, debris, or other naturally
occurring deposits from the job site 102; and for dumping such
earth materials at a designated location e.g., within a container
of a truck, or at another designated location on the job site
102.
[0023] Although the exemplary machine 100 is embodied as a WL in
the illustrated embodiment of FIG. 1, other types of machines
including, but not limited to, shovels, diggers, hydraulic
excavators, and the like can be optionally used in lieu of the WL
to implement the embodiments of the present disclosure. Therefore,
it may be noted that the embodiments of the present disclosure can
be similarly applied to other types of machines without deviating
from the spirit of the present disclosure. Moreover, for purposes
of the present disclosure, the machine 100 may be regarded as a
manually-operated machine having automated functions operably
executable via user controls 300 and a controller 406 provided
therein (also shown in FIGS. 5-6).
[0024] Referring to FIG. 1, the machine 100 may include a frame 106
configured for supporting a cab 126, a drive system 108, a linkage
110, a work implement 112, and multiple ground engaging members
e.g., wheels 114. The cab 126 may include a door 128 that is
configured to allow access to an operator for entering and exiting
the cab 126. As such, the cab 126 could be sized and shaped to
house an operator of the machine 100.
[0025] The work implement 112 may be any implement for carrying and
releasing a load. In embodiments, the work implement 112 may be
configured to carry and dump a load of loose material, in which
case it may include a moveable blade, jaws, or other features as
required to scoop, dump and otherwise manipulate the loose
material. In yet further embodiments, the work implement 112 may be
configured to handle a specialized load, for example, as a fork or
grapple arrangement for handling logs or other large objects.
[0026] In the illustrated embodiment, the work implement 112 is
configured as a bucket, which has fixed walls 113 and one open side
115 through which a load of loose material can be introduced into
the bucket. The work implement 112 is pivotable to define an
angular position of the work implement 112 in a range of movement
between an upwardly open position and a downwardly open position
e.g., when the bucket is dumping out the scooped material; wherein
the position of the open side 115 is taken to define the position
of the work implement 112 as upwardly, downwardly, or forwardly
open. An example of the forwardly open position of the work
implement 112 may include, when the open side 115 of the work
implement 112 is tilted away from the linkage 110 so as to be in a
ready-to-get position relative to a pile of material
[0027] The drive system 108 may include an engine (not shown), an
electric motor e.g., a traction motor (not shown), or both
depending on specific requirements of an application. The drive
system 108 is configured to produce and transmit output power to
the wheels 114 and the linkage 110 so as to perform certain desired
functions using the work implement 112 of the machine 100. The
desired functions can be, for example, digging, dumping, hauling,
etc. Referring to FIG. 1, only one side of the machine 100 is
illustrated and hence, only two wheels 114 are visible. However, it
should be noted that a similar pair of wheels (not shown) are
present on the other side of the machine 100 as well.
[0028] In an embodiment as shown in FIG. 1, the linkage 110 may
include a lift arm 116 that is pivotally coupled to the frame 106
of the machine 100. The linkage 110 also includes an actuator i.e.,
a hydraulic cylinder 122 pivotally coupled to the frame 106 and the
lift arm 116. Movement of the lift arm 116 can be actuated using
the hydraulic cylinder 122 for lowering or raising the work
implement 112 relative to the frame 106. The linkage 110 also
includes a lever link 118, a work implement link 120, and another
actuator, such as a hydraulic cylinder 124, as shown in FIG. 1. One
end of the hydraulic cylinder 124 may be pivotally coupled to the
frame 106 while another end of the hydraulic cylinder 124 may be
pivotally coupled to the lever link 118. Likewise, the lever link
118 may be pivotally coupled to the work implement link 120 remote
from where the hydraulic cylinder 124 is coupled to the lever link
118. Moreover, the work implement link 120 may be rigidly connected
to the work implement 112 remote from where the lever link 118 is
pivotally coupled to the hydraulic cylinder 124.
[0029] As the linkage 110 is operatively driven by the drive system
108, the linkage 110, upon receipt of appropriate commands from the
user controls 300, can initiate a movement of the work implement
112 relative to the frame 106 of the machine 100 during operation.
Accordingly, the work implement 112 can perform functions such as,
but not limited to, digging, dumping, hauling, or handling material
relative to a work surface 104 of the job site 102. Specifically,
with appropriate commands from the user controls 300 to the
hydraulic cylinder 122, the lift arm 116 can be moved relative to
the frame 106 for lowering or raising a position of the work
implement 112 relative to the work surface 104 of the job site 102.
Likewise, with appropriate commands from the user controls 300 to
the hydraulic cylinder 124, the lever link 118 and the work
implement link 120 can be moved relative to the lift arm 116 for
tilting the work implement 112 upwardly or downwardly relative to
the lift arm 116. Therefore, the user controls 300 may be operated
for maneuvering the linkage 110 and subsequently positioning the
work implement 112 in a range of discrete positions within a range
of movement of the work implement 112 for performing functions
consistent with the present disclosure. In embodiments of the
present disclosure, it is contemplated that the user controls 300
may be advantageously configured to receive user inputs from an
operator for issuing at least one of two types of commands--user
commands and kick-out commands. The user commands may include any
continuous user inputs using the user controls 300 so that the
operator may manually implement a control in the movement of the
work implement 112 to any discrete position within the range of
movement of the work implement 112. It is hereby contemplated that
a direction and speed of movement of the work implement 112 may
also be determined from the type of user input issued through the
user controls 300.
[0030] The kick-out command may include any user input from the
user controls 300 with which the operator may command the work
implement 112 to move to a pre-defined position (a "kick-out
position") within the range of movement of the work implement 112.
The user controls 300 may be configured with such kick-out commands
so as to move the work implement 112 to corresponding pre-defined
kick-out positions. Therefore, for the purposes of the present
disclosure, it may be noted that the user commands and the kick-out
commands are mutually exclusive of each other.
[0031] Referring to FIGS. 5-6, the user controls 300 includes at
least one primary control 302. The primary control 302 may include
one or more levers, a joystick, or any other control or controls
that can receive user input.
[0032] Movement of the primary control 302 may determine both the
direction and the speed of movement of the work implement 112. For
example, a speed of movement of the work implement 112 may be
proportional to the degree of displacement of the primary control
302 from its neutral position CC'. Moreover, as shown in FIGS. 5-6,
the primary control 302 may have one axis of movement to control
one function of the machine 100 or more than one axis of movement
to control more than one functions of the machine 100. In the
illustrated example, the primary control 302 has two axes of
movement AA' and BB' respectively, each of which may be provided to
control different ones of the hydraulic cylinders 122, 124 and
accomplish different movements of the work implement 112. In
various embodiments of the present disclosure, it may also be noted
that the primary control 302 is also resiliently biased to the
neutral position CC', wherein such neutral position CC'
beneficially corresponds with an intersection of axes AA' and BB'
as shown in FIGS. 5-6.
[0033] In an embodiment of this disclosure, the primary control 302
can be moved to discrete positions along each of the axes AA' and
BB' for issuing various user commands. For example, the primary
control 302 may be moved forwardly along axis AA' i.e., forward of
axis CC' for causing the hydraulic cylinder 122 to lower the work
implement 112 relative to the frame 106. Similarly, the primary
control 302 may be moved rearwardly along axis AA' i.e., rearward
of axis CC' causing the hydraulic cylinder 122 to raise the work
implement 112 relative to the frame 106. Further, the primary
control 302 can be tilted leftward along axis BB' i.e., leftward of
axis CC' for commanding the hydraulic cylinder 124 to cause an
upward tilting or racking of the work implement 112 relative to the
lift arm 116. Similarly, the primary control 302 can be tilted
rightward along axis BB' i.e., rightward of axis CC' for commanding
the hydraulic cylinder 124 to cause a downward tilting of the work
implement 112 relative to the lift arm 116.
[0034] Additionally, the primary control 302 can be moved to
pre-defined positions about axis CC' for issuing various kick-out
commands. Some examples of kick-out commands may include, but is
not limited to, a raise kick-out command in response to which the
work implement 112 may be raised to a pre-defined raise kick-out
position relative to the frame 106 as shown in FIG. 2, a lower
kick-out command in response to which the work implement 112 may be
lowered to a pre-defined lower kick-out position relative to the
frame 106 as shown in FIG. 4, a dump kick-out command in response
to which the work implement 112 is tilted downwardly to a
pre-defined dump kick-out position relative to the lift arm 116 as
shown in FIG. 3, a rack-back kick-out command in response to which
the work implement 112 is tilted upwardly to a pre-defined
rack-back position relative to the lift arm 116 as shown in FIG. 2,
and a ready-to-dig kick-out command in response to which the work
implement 112 is tilted to a pre-defined forwardly-open position
relative to the lift arm 116 as shown in FIG. 4.
[0035] It may be noted that the ready-to-dig kick-out command could
cause a tilting-up or a tilting down of the work implement 112
depending on a current angular position of the work implement 112
relative to the lift arm 116. In an example, if the work implement
112 is currently disposed in an upwardly facing position, issuance
of a ready-to-dig kick-out command can cause a downward tilting of
the work implement 112 to the ready-to-dig kick-out position e.g.,
the pre-defined ready-to-dig kick-out position shown in FIG. 4. On
the contrary, if the work implement 112 is currently disposed in a
downwardly facing position, issuance of a ready-to-dig kick-out
command can cause an upward tilting (racking) of the work implement
112 to the ready-to-dig kick-out position e.g., the pre-defined
ready-to-dig kick-out position shown in FIG. 4.
[0036] Although each of the above-mentioned kick-out commands are
explained in conjunction with FIGS. 2-4, it should be noted that
the raise and lower kick-out commands are executed independently of
the rack-back, dump, and/or ready-to-dig kick-out commands as the
raise and lower kick-out commands are executed by movement of the
hydraulic cylinder 122 while the rack-back, dump, and/or
ready-to-dig kick-out commands are executed by movement of the
hydraulic cylinder 124. To that end, it must be noted that the
foregoing examples relating to the various kick-out commands in
conjunction with FIGS. 2-4 should be regarded as being independent
of each other. As such, FIG. 2 shows a raise kick-out and a
rack-back kick-out implemented on the work implement 112 of the
machine 100, FIG. 3 shows a raise kick-out and a dump kick-out
implemented on the work implement 112 of the machine 100, and FIG.
4 shows a lower kick-out and a ready-to-dig kick-out implemented on
the work implement 112 of the machine 100.
[0037] The pre-defined positions of the primary control 302 may
include, e.g., extreme positions along axes AA' and BB'. For
example, the primary control 302 may be moved to an extreme
position located forward of axis CC' i.e., forwardly along axis AA'
for moving the work implement 112 to the pre-defined lower kick-out
position shown in FIG. 4. Similarly, in another example, the
primary control 302 may be moved to an extreme position located
rearward of axis CC' i.e., rearwardly along axis AA' for moving the
work implement 112 to the pre-defined raise kick-out position shown
in FIG. 2. In yet another example, the primary control 302 may be
moved to an extreme position located leftward of axis CC' i.e.,
along axis BB' for tilting the work implement 112 upwardly to the
pre-defined rack-back position shown in FIG. 2. Similarly, the
primary control 302 may be moved to an extreme position located
rightward of axis CC' i.e., along axis BB' for tilting the work
implement 112 downwardly to the pre-defined dump kick-out position
shown in FIG. 2. In various embodiments, it is also contemplated
that the kick-out commands from the primary control 302 may be
recognized and/or differentiated from user commands based inter
alia upon factors such as speed of movement of the primary control
302 to a particular user commanded or user-defined kick-out
position, a dwell time of the primary control 302 at the particular
user commanded or user-defined kick-out position.
[0038] It should be noted that in various embodiments herein, the
positions of the linkage 110 and the work implement 112
corresponding to each type of kick-out command can be pre-defined
and stored at a memory device (not shown) associated with the
controller 406. Some examples of memory devices may include, but is
not limited to, read only memory (ROM), random access memory (RAM),
floppy disks, compact disks, portable hard disks, and the like.
Such devices may be contemplated for use with the controller 406 to
execute functions that are consistent with the present
disclosure.
[0039] Referring to FIGS. 5-6, the user controls 300 may further
include a secondary control 304 mounted on the primary control 302.
In an example, the secondary control 304 may be, e.g., a
thumb-rocker switch as shown in FIGS. 5-6. In embodiments of this
disclosure, the secondary control 304 may be configured to swivel,
rightwardly or leftwardly, about axis CC'. Moreover, the secondary
control 304 may be configured to be resiliently biased to a neutral
position disposed in line with axis AA'. It has been contemplated
that an operator of the machine 100 can optionally use the
secondary control 304, in lieu of the primary control 302, for
issuing user commands to actuate the hydraulic cylinder 124 for
causing an upward tilting of the work implement 112 or a downward
tilting of the work implement 112 relative to the lift arm 116. For
example, the secondary control 304 could be configured such that a
leftward swiveling of the secondary control 304 about axis CC' may
cause an upward tilting/racking of the work implement 112 relative
to the lift arm 116 while a rightward swiveling of the secondary
control 304 about axis CC' may cause a downward tilting of the work
implement 112 relative to the lift arm 116.
[0040] In embodiments of the present disclosure, it is also
contemplated that the user controls 300 may further include at
least one switch other than the secondary control 304. As shown in
FIGS. 5-6, the user controls 300 further includes a pair of
switches 306, 308. In the illustrated embodiment, each of the
switches 306, 308 may be embodied as push button switches. However,
in other embodiments, it can be contemplated by persons skilled in
the art to include other types of switches such as, but not limited
to, toggle switches, rocker switches, or rotary knobs in lieu of
the push button switches. Preferably, the switches 306, 308, may be
momentary switches that only require a brief activation by the
operator to generate an operator signal for carrying out an
automated work function.
[0041] In embodiments of the present disclosure, it is further
contemplated that each of the switches 306, 308 is beneficially
configured with at least one of the kick-out commands so as to
implement at least one of the various pre-defined kick-out
positions associated with the work implement 112. It will also be
appreciated that in an embodiment, at least one of the switches
306, 308 can also be beneficially configured with more than one
kick-out command so as to cause both the hydraulic cylinders 122,
124 of the machine 100 to execute movements of the work implement
112 corresponding to more than one type of pre-defined kick-out
position, for example, the pre-defined raise kick-out position and
the pre-defined dump kick-out position of the work implement 112 as
shown in FIG. 3.
[0042] It will be further appreciated that when more than one
kick-out command is associated with any of the switches 306, 308,
movements corresponding to such kick-out commands may be carried
out by the hydraulic cylinders 122, 124 simultaneously, tandemly,
or with a phase shift between the individual movements, each of
which can be contemplated for implementation by way of
embodiments.
[0043] In an embodiment of this disclosure, it is contemplated that
the switch 306 on the primary control 302 is incorporated with a
ready-to-dig kick-out command. The switch 306 would therefore be
operable to command a movement of the hydraulic cylinder 124 for
causing a tilting of the work implement 112, upwardly or
downwardly, to the pre-defined ready-to-dig position (forwardly
facing position of the open side 115 as shown in FIG. 3. The
aforesaid tilt movements being based on a current angular position
of the work implement 112 relative to the lift arm 116.
[0044] Likewise, it is contemplated that the switch 308 on the
primary control 302 be incorporated with the lower kick-out
command. The switch 308 would therefore be operable to command a
movement of the hydraulic cylinder 122 for lowering the work
implement 112 to a pre-defined lower kick-out position e.g., to the
pre-defined lower kick-out position shown in FIG. 4. In the
foregoing embodiments, it is disclosed that the ready-to-dig
kick-out command and the lower kick-out command are incorporated
for implementation with switches 306 and 308. It should be noted
that the ready-to-dig kick-out command and the lower kick-out
command have been disclosed in conjunction with the switches 306,
308 respectively as it is envisioned that the ready-to-dig kick-out
command and the lower kick-out command may be frequently required
for use during an earth-moving operation of the machine 100.
However, in other embodiments, it should be noted that any type of
kick-out command can be incorporated for use with the switches 306,
308. Also, one skilled in the art will acknowledge that in other
embodiments, additional switches may be provided in the user
controls 300 for incorporation and implementation of other
kick-outs besides the ready-to-dig kick-out command and the lower
kick-out command implemented with the switches 306 and 308,
respectively.
[0045] As shown in FIG. 7, a schematic of a control system 400 that
can be employed in conjunction with the machine 100 is illustrated.
It will be appreciated that the user controls 300 i.e., the primary
control 302, the secondary control 304, the switch 306, and the
switch 308 also form part of the control system 400.
[0046] The control system 400 also includes the controller 406
communicably coupled to each of the user controls 300 i.e., the
primary control 302, the secondary control 304, the switch 306, and
the switch 308. The controller 406 is configured to receive user
commands from the primary control 302, and/or the secondary control
304.
[0047] Responsive to receiving a user command from the primary
control 302 and/or the secondary control 304, the controller 406
moves the work implement 112 to a position defined by the user
command from the primary control 302, the secondary control 304.
Such user commands may be implemented by the controller 406 at the
linkage 110 as a function of the movement of the primary control
302 relative to its neutral position i.e., axis CC', or the
swiveling movement of the secondary control 304 relative to its
neutral position disposed in line with axis AA' depending on which
one of the user controls 300 i.e., the primary control 302 or the
secondary control 304 is being operated.
[0048] The controller 406 is also configured to receive one or more
kick-out commands from the user controls 300. Specifically, in an
embodiment, the controller 406 may be configured to receive one or
more kick-out commands from the primary control 302 and/or at least
one the switches 306, 308. For example, the controller 406 may
receive a lower kick-out command from the switch 308.
[0049] The control system 400 further includes a load sensor 402,
and a position sensor 404 communicably coupled to the controller
406. The load sensor 402 is configured to generate load data
indicative of a sensed load of the work implement 112. Some
examples of the load sensors 402 may include, but is not limited
to, strain gauges, load cells, or any other load measuring devices
known to one skilled in the art. Therefore, it should be noted that
a type of the load sensor 402 used is merely exemplary in nature
and hence, non-limiting of this disclosure.
[0050] The position sensor 404 is configured to generate position
data indicative of a sensed position of the work implement 112.
Some examples of position sensors 404 may include, but is not
limited to, hall-effect sensors, displacement sensors, proximity
sensors, capacitive transducers or any other position measuring
devices known to one skilled in the art. Therefore, it should be
noted that a type of the position sensor 404 used is merely
exemplary in nature and hence, non-limiting of this disclosure.
Moreover, it should be noted that although one load sensor 402 and
one position sensor 404 is depicted in the illustrated embodiment
of FIG. 4, any number of the load sensor 402, and the position
sensor 404 could be used to suit specific requirements of an
application.
[0051] The controller 406 is further configured to receive the load
data and position data of the work implement 112 from the load
sensors 402, and the position sensor 404 respectively. Upon receipt
of the load data of the work implement 112, the controller 406
determines a load state of the work implement 112 based on the
received load data, and accepts or rejects the kick-out command
based on at least the load state of the work implement 112.
[0052] In an exemplary embodiment, control data pertaining to a
maximum value of load that can be carried by the work implement 112
may be provided before-hand to the controller 406. The controller
406 may compare the load state of the work implement 112 with such
control data to ascertain if the work implement 112 is
substantially loaded. In another exemplary embodiment, such control
data may include control data corresponding to the various points
in the range of movement of the work implement 112. In this
embodiment, the controller 406 can also accept or reject the
kick-out command based on both the load state of the work implement
112 and the position data obtained from the position sensor
404.
[0053] In an embodiment of this disclosure, the controller 406 is
configured to reject the lower kick-out command if the load state
of the work implement 112 indicates that the work implement 112 is
substantially loaded. Regardless of whether the lower kick-out
command has been issued from the primary control 302 or the switch
308, the controller 406 rejects any lower kick-out commands if the
controller 406 determines that the work implement 112 is
substantially loaded. In an exemplary embodiment, the controller
406 could compare the load state of the work implement 112 with the
control data to ascertain if the sensed load of the work implement
112 has exceeded one or more pre-determined threshold values
obtained from the control data. If so, the controller 406 could
reject the lower kick-out command from either one of: the primary
control 302 or the switch 308. This way, the controller 406 can
prevent the work implement 112 from rapidly descending when
substantially loaded, and inducing excessive and undesired
oscillation in the machine 100.
[0054] The controller 406 could include various software and/or
hardware components that are configured to perform functions
consistent with the present disclosure. As such, the controller 406
of the present disclosure may be a stand-alone controller or may be
configured to co-operate with an existing electronic control module
(ECU) (not shown) of the machine 100. Further, the controller 406
may embody a single microprocessor or multiple microprocessors that
include components for controlling movement of the work implement
112 based on the load state of the work implement 112 alone or in
conjunction with the sensed position data of the work implement 112
received from the load sensor 402 and the position sensor 404.
Numerous commercially available microprocessors can be configured
to perform the functions of the controller 406. It should be
appreciated that the controller 406 could readily be embodied in a
general machine microprocessor capable of controlling numerous
machine functions. The controller 406 may include a memory, a
secondary storage device, a processor, and any other components for
running an application. Various other circuits may be associated
with the controller 406 such as power supply circuitry, signal
conditioning circuitry, solenoid driver circuitry, and other types
of circuitry. Various routines, algorithms, and/or programs can be
programmed within the controller 406 for execution thereof to
actuate a movement of the linkage 110 in relation to the frame 106
of the machine 100 based on the sensed load data alone or in
conjunction with the sensed position data of the work implement 112
received from the load sensor 402 and the position sensor 404.
[0055] It may be noted that in various embodiments, the controller
406 could be further configured to interpret the movement of the
primary control 302 to an extreme position, either as a kick-out
command or not, based inter alia on factors such as, but not
limited to, a speed of movement of the primary control 302 to the
extreme position, a return speed of the primary control 302 back to
neutral position i.e., axis CC', and/or a dwell time of the primary
control 302 at the extreme position. One skilled in the art will
acknowledge that various other factors associated with movement of
the primary control 302 may be, additionally or optionally,
incorporated by the controller 406 for determining if the primary
control 302 has been moved to issue a kick-out command or not.
[0056] In another embodiment herein, the controller 406 may also be
configured to reject the lower kick-out command if the work
implement 112 is currently positioned in the downwardly open
position. Regardless of whether the lower kick-out command has been
issued from the primary control 302 or the switch 308, the position
sensor 404 may indicate to the controller 406 that the work
implement 112 is currently in a downwardly open position thereby
facilitating the controller 406 to reject any lower kick-out
commands while the work implement 112 remains in the downwardly
open position. This way, the controller 406 can prevent the work
implement 112 from slamming against the ground or a loading truck
(not shown) given the downwardly open position of the work
implement 112.
[0057] It is also contemplated by way of embodiments herein that
the controller 406 is also configured to reject any lower kick-out
commands from the switch 308 if the primary control 302 is not
currently positioned in a neutral position i.e., when the primary
control 302 is not positioned along axis CC' to which the primary
control 302 is normally biased (refer to FIGS. 5-6). This way, the
controller 406 eliminates a possibility of lowering the lift arm
116 and the work implement 112 to the pre-defined lower kick-out
position relative to the frame 106 of the machine 100 if the
primary control 302 currently remains positioned away from axis CC'
pursuant to issuing other user commands such as raising,
tilting-down, and racking-back the work implement 112. However, if
the current position of the primary control 302 corresponds to a
lowering command of the work implement 112, the controller 406
could allow the lower kick-out command based at least on the load
state of the work implement 112, and the sensed position data of
the work implement 112.
[0058] The controller 406 may also be configured to reject any
kick-out commands associated with the switches 306, 308 if the
kick-out command associated with such switches 306, 308 is contrary
to a current operation being carried out by the work implement 112
under previously issued user commands from the primary control 302
or the secondary control 304. For example, if the primary control
302 is moved rearward of axis CC' to command a raising of the work
implement 112 relative to the frame 106 and during such time if the
switch 308 has been depressed for lowering the work implement 112
relative to the frame 106, then the controller 406 can reject the
contradicting kick-out request arising from actuation of the switch
308. With such implementation, the controller 406 can be configured
to beneficially interpret the actuation of the switches 306, 308 as
an inadvertent actuation (one that could cause an unintended manner
of operation for the machine 100) and hence, ignores the kick-out
request from any of the switches 306, 308.
[0059] In a further embodiment, the controller 406 may be
additionally configured to reject the lower kick-out command from
the primary control 302 or the switch 308 if the secondary control
304 is not in a neutral position i.e., in line with axis CC'. If
the secondary control 304 has been swiveled, rightwardly or
leftwardly, about axis CC', then the controller 406 ignores any
lower kick-out request issued from the primary control 302 or the
switch 308. In a particular embodiment, by swiveling the secondary
control 304 rightward of axis CC', the work implement 112 may be
commanded to tilt downwardly relative to the lift arm 116. At this
point, the controller 406 can reject any lower kick-out commands
from the primary control 302 or the switch 308 and beneficially
prevent the work implement 112 from descending rapidly and causing
the front face of the work implement 112 to slam against a
container of the truck or into the ground.
[0060] Also, in another particular embodiment, by swiveling the
secondary control 304 leftward of axis CC', the work implement 112
may be commanded to tilt upwardly relative to the lift arm 116.
Assuming that a user command has been issued from the primary
control 302 for tilting the work implement 112 upwardly, and a
lower-kick out command has been issued from the switch 308 to the
controller 406; the controller 406 determines the load state of the
work implement 112 from the sensed load data for ascertaining if
the work implement 112 is substantially loaded. If so, the
controller 406 can prevent the lower kick-out command from being
implemented at the work implement 112.
[0061] In an exemplary embodiment, the controller 406 could compare
the load state of the work implement 112 with the control data. In
one embodiment, the control data could provide a single threshold
load value (i.e., a stored value at a memory (not shown) of the
controller 406 which are used for comparison with the sensed load
to determine the load state of the work implement 112) that may be
independent of position data of the work implement 112 received
from the position sensor 404. Such a threshold value may be
implemented within the controller 406 for comparing and determining
if the load state of the work implement 112 exceeds the single
threshold value and subsequently determining if the work implement
112 is substantially loaded or not.
[0062] It is hereby further contemplated that in other embodiments,
the control data could provide multiple threshold load values that
correspond to each position or a group of positions within the
geometry of movement of the work implement 112. The multiple
threshold load values may include multiple stored values at the
memory of the controller 406 which are used for comparison with the
sensed load data associated with corresponding positions or group
of positions in the geometry of movement of the work implement 112
to determine the load states of the work implement 112 at such
corresponding positions or group of positions in the geometry of
movement of the work implement 112.
[0063] When the work implement 112 is operated to a given position
and a kick-out command is issued, the controller 406 may determine
if the load state of the work implement 112 exceeds the maximum
limit of load for the work implement 112 at the pre-defined
kick-out position. If so, the controller 406 rejects any lower
kick-out commands issued from the switch 308 and can therefore,
prevent the work implement 112 from descending rapidly and inducing
excessive and undesired oscillations in the machine 100. However,
if the controller 406 determines that the load state of the work
implement 112 does not exceed a maximum limit of load from the
control data for the work implement 112 at the pre-defined kick-out
position, then the controller 406 can accept the lower kick-out
command issued from the switch 308, and appropriately command
movement of the lift arm 116 to the pre-defined lowered
position.
[0064] In various embodiments of the present disclosure, it is
further contemplated that the controller 406 can be further
configured to reject kick-out commands from the switches 306, 308
if the kick-out commands at the switches 306, 308 have not been
initiated and maintained in such initiation state for a minimum
amount of time period. Such minimum amount of time period for which
the kick-out commands at the switches 306, 308 should be maintained
in the initiation state includes maintaining the initiation state
without an interrupt for allowing the controller 406 to accept a
kick-out request from any one or both of the switches 306, 308,
more specifically, a lower kick-out request from the switch 308.
The minimum amount of time period may lie in the order of a few
milliseconds to a few seconds e.g., 100 milliseconds. Such
implementation of incorporating a minimum amount of time period at
the controller 406 for which the actuation of the switches 306, 308
must be maintained in the initiation state continuously without
interruption could serve as a pre-requisite in the controller 406
for helping the controller 406 to ascertain if the kick-out/s
commanded from actuation of the switches 306 and/or 308 are
intentional or unintentional.
[0065] In various embodiments of this disclosure, it may be noted
that the acceptance or rejection of kick-out commands is being
explained in conjunction with the lower kick-out command in
response to which the work implement 112 is lowered to a
pre-defined lowered position set by the operator of the machine
100. However, a scope of the present disclosure should not be
construed as being limited to the lower kick-out command alone.
Rather a scope of the present disclosure can extend to
implementation of the present controller 406 with capabilities for
accepting or rejecting various other types of kick-out commands
e.g., commonly known kick-outs including, but not limited to, raise
kick-out, dump-kick-out, rack-back kick-out and the like while
taking into account the criteria associated with the sensed load
and position of the work implement 112.
INDUSTRIAL APPLICABILITY
[0066] The present disclosure may be applied to any machine that
has a work implement to selectively disallow inadvertent or
inappropriate kick-out commands. Some examples of such a machine
may include shovels, diggers, hydraulic excavators, but is not
limited thereto. Moreover, the present disclosure may be
implemented for controlling a movement of other types of work
implements typically associated with such machines.
[0067] Conventionally, a control in the movement of the work
implement may have been accomplished on the basis of the position
of the operating levers and on the previously executed movements of
the machine. However, with use of various embodiments, the load
condition of the work implement may be advantageously taken as an
indicator, not merely of whether a kick-out command results from an
accidental or deliberate activation of the user controls, but
rather, of the appropriateness of the kick-out command in the
particular use condition of the machine at the moment the kick-out
command is received. Further advantageously, the step of accepting
or rejecting the kick-out command may be accomplished based on
sensor input indicating the present condition of the machine
without reference to, for example, any stored history of previously
executed operator commands or machine movements.
[0068] The principle of allowing or disallowing a kick-out based on
the load condition of the work implement may thus be applied to
mitigate the effects of inadvertent operation of the user controls,
irrespective of whether the inadvertency is, for example, an
accidental switch activation or a deliberate switch activation
resulting from the inattention or inexperience of the machine
operator, and irrespective of whether such inattention is reflected
by the presence or absence of preceding operator commands that fall
into an expected pattern or, on the contrary, reflects a momentary
lapse in concentration. The principle thus applies equally in
situations where operator commands follow an expected pattern, and
in situations where operator commands diverge from an expected
pattern to properly reflect the rapidly changing extraneous
conditions of a work environment such as vehicle or pedestrian
movements in the vicinity of the machine.
[0069] The principle of allowing or disallowing a kick-out based on
the load condition of the work implement recognizes that whereas an
inadvertent kick-out command may be countermanded by the operator,
for example, by appropriately moving the joystick, a loaded work
implement can result in unexpectedly rapid movement, which means
that the contrary command must be given very quickly. However, the
momentum of the loaded work implement may potentially cause some
instability in the machine and also damage the hydraulic circuits
of the machine if its motion is suddenly interrupted. This may
occur, for example, during a lower kick-out, and may result in
damage to the work implement if its momentum is sufficient to carry
it beyond the pre-defined lowered position causing it to hit the
ground.
[0070] In another example, if the kick-out command is a
return-to-dig kick-out and the work implement is in the upwardly
open position, the rapid movement of a loaded work implement to the
forwardly open or return-to-dig position would be an unusual
movement and hence unlikely to reflect the intention of the
operator, and even if intentional, may nevertheless potentially
stress the actuator and linkage when the movement of the work
implement is arrested in the forwardly open position.
[0071] To mitigate these risks, as discussed above, the controller
may be configured to reject the kick-out command where the work
implement load state in combination with the work implement
position and the direction of the kick-out may give rise to the
potential for damage or instability of the machine if the kick-out
were executed.
[0072] FIG. 8 is a flowchart illustrating a method 800 for
controlling a machine e.g., the machine 100. The machine 100
includes the work implement 112 mounted on the linkage 110. The
linkage 110 also includes hydraulic cylinder 122 connected to the
lift arm 116 and the hydraulic cylinder 124 connected to the work
implement link 120 via the lever link 118 and operable by the
controller 406 to move the work implement 112 in a range of
movement associated with the work implement 112. Moreover, the load
sensor 402 and the position sensor 404 and the user controls 300
are communicably coupled to the controller 406. The load sensor 402
and the position sensors 404 are being configured to send a sensed
load and position data of the work implement 112 to the controller
406 while the user controls 300 are operable for issuing user
commands and kick-out commands to the controller 406.
[0073] Referring to FIG. 8, at block 802, the method 800 includes
sending a user command from the primary control 302 e.g., the
joystick, or from the secondary control 304 e.g., the thumb-rocker
switch to the controller 406. The user command could include a
command for raising, lowering, racking-back, or tilting-down the
work implement 112 to a position defined by the user command. At
block 804, the method 800 further includes moving the work
implement 112 to a position defined by the user command from the
primary control 302 or the secondary control 304. Depending on a
manner of movement of the primary control 302 i.e., rightward,
leftward, forward, or rearward of axis CC', or a manner of
swivelling movement, leftward or rightward of axis CC', of the
secondary control 304 by the operator; the controller 406 can
actuate a movement of the linkage 110 and command a movement of the
work implement 112 to a position defined by the user command from
the primary control 302 or the secondary control 304.
[0074] At block 806, the method 800 further includes receiving a
kick-out command from the user controls 300 i.e., the primary
control 302, the switch 306, and/or the switch 308. It has been
contemplated that the kick-out commands from the primary control
302 may be recognized and/or differentiated from the user commands
based inter alia upon factors such as speed of movement of the
primary control 302 to a particular user commanded or user-defined
kick-out position, a dwell time of the primary control 302 at the
particular user commanded or user-defined kick-out position.
[0075] Therefore, as disclosed earlier herein, the primary control
302 could be moved to pre-defined kick-out positions e.g., extreme
positions along each of the axes AA' and BB' to provide the
corresponding kick-out pre-defined to the controller 406. Moreover,
the kick-out command being incorporated with the switch 306 could
preferably include the ready-to-dig kick-out. Similarly, the
kick-out command being associated with the switch 308 could
preferably include a lower kick-out for lowering the lift arm 116
and causing a subsequent movement of the work implement 112 to the
pre-defined lowered position. The switches 306, 308 can therefore,
be operated to issue a ready-to-dig kick-out or a lower kick-out
command to the controller 406.
[0076] At block 808, the method 800 further includes receiving load
data and position data of the work implement 112 by the controller
406. The load sensor 402, and the position sensor 404 are
configured to generate and transmit load data and position data
associated with the work implement 112 to the controller 406. At
block 810, the method 800 includes determining, by the controller
406, a load state of the work implement 112 on the basis of at
least the sensed load data.
[0077] At block 812, the method 800 further includes accepting or
rejecting the kick-out command received by the controller 406 on
the basis of at least load state of the work implement 112. For
example, if the controller 406 determines that the current load
state of the work implement 112 is greater than the maximum limit
prescribed by the control data known to the controller 406, the
controller 406 can reject any of the kick-out requests, more
specifically a lower-kick-out request that may be issued from the
primary control 302 or the switch 308, and thereafter the method
800 terminates. However, if the controller 406 determines that the
load state of the work implement 112 is less than the maximum limit
prescribed by the control data, the controller 406 accepts the
kick-out commands and the method 800 proceeds to block 814 where
the controller 406 moves the work implement 112 to the pre-defined
kick-out position e.g., a ready-to-dig position corresponding to an
actuation of the switch 306 or a lower kick-out position
corresponding to an actuation of the switch 308.
[0078] It will be understood that embodiments may be implemented in
wheel loaders and other machines which allow the operator to
initiate a kick-out function, whether via a primary control or
alternatively or additionally via a separate kick-out control,
preferably a switch such as a button. In the latter case, by
allowing or disallowing a kick-out based on at least the load
condition of the work implement, the disadvantageous consequences
of accidental operation of the additional kick-out control may be
substantially mitigated. Therefore, it will be appreciated that
with implementation of many embodiments, a maximum production of
the machine 100 can be maintained through rapid movements of the
linkage 110 while the control system 400 of the present disclosure
helps to prevent inadvertent or accidental operations of the
machine 100.
[0079] Although embodiments of the present disclosure are explained
in conjunction with a WL having a work implement, other types of
machines such as, but not limited to, shovels, diggers, hydraulic
excavators, and the like can be optionally used to implement the
embodiments herein. Moreover, embodiments of the present disclosure
can also be implemented with other types of work implements
typically associated with various types of earth moving machines
known in the art. For example, if the machine 100 were embodied in
the form of a hydraulic excavator having an excavating work
implement, then a ready-to-dig function could be implemented by a
rearwardly facing position of the excavating work implement in lieu
of the forwardly open position of the work implement 112 disclosed
in conjunction with the WL herein. Various other modifications may
be contemplated by persons skilled in the art and such
modifications are considered to fall within the scope of the
appended claims.
[0080] While aspects of the present disclosure have been
particularly shown and described with reference to the embodiments
above, it will be understood by those skilled in the art that
various additional embodiments may be contemplated by the
modification of the disclosed machines, systems and methods without
departing from the spirit and scope of what is disclosed. Such
embodiments should be understood to fall within the scope of the
present disclosure as determined based upon the claims and any
equivalents thereof.
* * * * *