U.S. patent application number 13/332017 was filed with the patent office on 2013-06-20 for implement control system for a machine.
This patent application is currently assigned to CATERPILLAR INC.. The applicant listed for this patent is Joshua Callaway. Invention is credited to Joshua Callaway.
Application Number | 20130158818 13/332017 |
Document ID | / |
Family ID | 48610981 |
Filed Date | 2013-06-20 |
United States Patent
Application |
20130158818 |
Kind Code |
A1 |
Callaway; Joshua |
June 20, 2013 |
Implement control system for a machine
Abstract
A system for automated movement of a ground engaging blade of a
machine includes a sensor on the blade to indicate a measured roll
rate of the ground engaging blade. A controller determines whether
the operator roll rate command is within an expected range of the
roll rate signal. Movement of the ground engaging blade is at least
in part based upon the operator roll rate command.
Inventors: |
Callaway; Joshua; (Cary,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Callaway; Joshua |
Cary |
NC |
US |
|
|
Assignee: |
CATERPILLAR INC.
Peoria
IL
|
Family ID: |
48610981 |
Appl. No.: |
13/332017 |
Filed: |
December 20, 2011 |
Current U.S.
Class: |
701/50 |
Current CPC
Class: |
E02F 3/845 20130101;
E02F 9/265 20130101; E02F 9/2041 20130101 |
Class at
Publication: |
701/50 |
International
Class: |
E02F 3/84 20060101
E02F003/84 |
Claims
1. A control system for automated movement of a ground engaging
blade of a machine, the ground engaging blade being configured for
rotational movement, comprising: a sensor located on the ground
engaging blade configured to provide a roll rate signal indicative
of a measured roll rate of the ground engaging blade; and a
controller configured to: receive the roll rate signal; receive an
operator roll rate command signal; determine whether the operator
roll rate command is within an expected range of the roll rate
signal; generate a command signal based at least in part on the
operator roll rate command signal; and transmit the command signal
to control movement of the ground engaging blade.
2. The control system of claim 1, wherein the roll rate signal
measures an angular velocity of the ground engaging blade about an
attachment point of the ground engaging blade to the machine.
3. The control system of claim 1, wherein the controller generates
a command signal generally equal to the operator roll rate command
signal if predetermined threshold conditions are not met.
4. The control system of claim 1, wherein the controller generates
the command signal to move the ground engaging blade in a direction
generally identical to a direction commanded by the operator roll
rate command signal.
5. The control system of claim 1, wherein the controller generates
the command signal to move the ground engaging blade in a direction
generally opposite to a direction commanded by the operator roll
rate command signal if the operator roll rate command is within the
expected range.
6. The control system of claim 1, wherein the command signal moves
the ground engaging blade when an operator has not commanded a
specific movement of the ground engaging blade.
7. The control system of claim 1, wherein the controller generates
a command signal generally equal to the operator roll rate command
signal if the operator roll rate command is outside the expected
range.
8. The control system of claim 7, wherein the controller is further
configured to attempt to maintain the roll rate signal generally
equal to a velocity of 0 if the operator roll rate command is
within the expected range.
9. The control system of claim 1, wherein the controller generates
a command signal based upon the operator roll rate command and the
roll rate signal and further attempts to maintain the roll rate
signal generally equal to a velocity of 0 if the operator roll rate
command is within the expected range.
10. The control system of claim 1, wherein the sensor is a
gyroscope.
11. A controller implemented method of adjusting a ground engaging
blade of a machine, the ground engaging blade having a sensor
configured to provide a roll rate signal indicative of a measured
roll rate of the ground engaging blade, comprising: receiving the
roll rate signal within a controller; receiving an operator roll
rate command signal within the controller; determining whether the
operator roll rate command is within an expected range of the roll
rate signal; generating a command signal within the controller
based at least in part on the roll rate signal and the operator
roll rate command signal; and transmitting the command signal from
the controller to control movement of the ground engaging
blade.
12. The controller implemented method of claim 11, further
including measuring an angular velocity of the ground engaging
blade about an attachment point of the ground engaging blade to the
machine.
13. The controller implemented method of claim 11, further
including generating a command signal generally equal to the
operator roll rate command signal if predetermined threshold
conditions are not met.
14. The controller implemented method of claim 11, further
including moving the ground engaging blade in a direction generally
identical to a direction commanded by the operator roll rate
command signal.
15. The controller implemented method of claim 11, further
including moving the ground engaging blade in a direction generally
opposite to a direction commanded by the operator roll rate command
signal if the operator roll rate command is within the expected
range.
16. The controller implemented method of claim 11, further
including moving the ground engaging blade when an operator has not
commanded a specific movement of the ground engaging blade.
17. The controller implemented method of claim 11, further
including the controller generating a command signal generally
equal to the operator roll rate command signal if the operator roll
rate command is outside the expected range.
18. The controller implemented method of claim 17, further
including attempting to maintain the roll rate signal generally
equal to a velocity of 0 if the operator roll rate command is
within the expected range.
19. The controller implemented method of claim 11, further
including attempting to maintain the roll rate signal generally
equal to a velocity of 0 if the operator roll rate command is
within the expected range.
20. A machine comprising: a ground engaging blade; a sensor located
on the ground engaging blade configured to provide a roll rate
signal indicative of a measured roll rate of the ground engaging
blade; and a controller configured to: receive the roll rate
signal; receive an operator roll rate command signal; determine
whether the operator roll rate command is within an expected range
of the roll rate signal; generate a command signal based at least
in part on the roll rate signal and the operator roll rate command
signal; and transmit the command signal to an electro-hydraulic
system to control movement of the ground engaging blade.
Description
TECHNICAL FIELD
[0001] This disclosure relates generally to controlling an
implement and, more particularly, to a system and method for
controlling the cross slope of a ground engaging blade.
BACKGROUND
[0002] Machines such as a tractors, bulldozers and the like are
often equipped with attached implements for performing various
tasks. For example, a tractor may be equipped with a ground
engaging blade for performing tasks such as scraping the ground and
moving material in a controlled fashion. An operator may move the
blade in various directions relative to the ground. This helps the
tractor complete the task of properly leveling or contouring the
ground on which the tractor is operating. This is a task often
performed during the construction of roads, buildings, or other
structures.
[0003] One difficulty when operating such a machine is maintaining
a consistent position of the blade as the tractor moves over uneven
terrain. Movement of the machine up and down and from side to side
results in similar movements of the blade despite a desire to
maintain the blade in a fixed orientation relative to a ground
reference. As a result of such movement, the work surface created
by the machine may be uneven and require additional work to create
a desired work surface.
[0004] An operator of a machine may correct for uneven terrain by
adjusting the motion of the blade as the machine moves to
compensate for the machine's movement, resulting in a smoother
surface. However, the quality of the resulting grade is dependent
on the skill of the operator in anticipating the need to adjust the
blade. The operator may, in addition or alternatively, slow the
speed of the machine while adjusting the blade position in response
to uneven terrain. Such operations tend to reduce efficiency and
increase cost.
[0005] U.S. Pat. No. 7,121,355 to Lumpkins et. al ("Lumpkins")
discloses a control system for controlling the position of a
machine blade for grading. The control system determines the
difference between a target position of the blade and its actual
position, and generates a control signal calculated to move the
blade to the target position.
[0006] The foregoing background discussion is intended solely to
aid the reader. It is not intended to limit the innovations
described herein, nor to limit or expand the prior art discussed.
Thus, the foregoing discussion should not be taken to indicate that
any particular element of a prior system is unsuitable for use with
the innovations described herein, nor is it intended to indicate
that any element is essential in implementing the innovations
described herein. The implementations and application of the
innovations described herein are defined by the appended
claims.
SUMMARY
[0007] In one aspect, a control system is provided for controlling
automated movement of a ground engaging blade of a machine. The
ground engaging blade is configured for rotational movement. The
sensor is located on the ground engaging blade and is configured to
provide a roll rate signal indicative of a measured roll rate of
the ground engaging blade. The controller is configured to receive
the roll rate signal, receive an operator roll rate command signal,
generate a command signal based at least in part on the roll rate
signal and the operator roll rate command signal, and transmit the
command signal to a system to control movement of the ground
engaging blade.
[0008] In another aspect, a controller implemented method of
adjusting a ground engaging blade of a machine is provided. The
ground engaging blade has a sensor configured to provide a roll
rate signal indicative of a measured roll rate of the ground
engaging blade. The method includes receiving the roll rate signal
within a controller, receiving an operator roll rate command signal
within the controller, generating a command signal within the
controller based at least in part on the roll rate signal and the
operator roll rate command signal, and transmitting the command
signal from the controller to a system to control movement of the
ground engaging blade.
[0009] In another aspect, a machine includes a ground engaging
blade, a sensor on the ground engaging blade configured to provide
a roll rate signal indicative of a measured roll rate of the ground
engaging blade, and a controller. The controller is configured to
receive the roll rate signal, receive an operator roll rate command
signal, generate a command signal based at least in part on the
roll rate signal and the operator roll rate command signal, and
transmit the command signal to a system to control movement of the
ground engaging blade.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a side view of a machine including a system in
accordance with the disclosure;
[0011] FIG. 2 shows a front view of a machine similar to that of
FIG. 1 with certain components removed and other components broken
away for clarity; and
[0012] FIG. 3 shows a flowchart illustrating a cross slope control
process in accordance with the disclosure.
DETAILED DESCRIPTION
[0013] FIG. 1 shows a diagrammatic illustration of a machine that
may be used in accordance with an embodiment of the disclosure. A
machine 10 includes a frame 12 and a prime mover such as an engine
13. A pair of drive wheels (one of which is illustrated as a drive
wheel 14) are disposed on each side of machine 10 and operate to
drive a pair of tracks (one of which is shown as a track 15) to
propel machine 10. Although machine 10 is shown in a "track-type"
configuration, other configurations, such as a wheeled
configuration, may be used. In addition, the systems and methods of
the disclosure may be used with any machine propulsion and drive
train mechanisms applicable in the art. Further, the systems and
methods disclosed herein may also be used on machines other than a
tractor having a ground engaging blade, such as a loader or a motor
grader.
[0014] Machine 10 includes an implement such as ground engaging
blade 16 pivotally connected to frame 12 by a pair of opposed arm
(one of which is illustrated as an arm 17) disposed on each side of
machine 10. A lift hydraulic cylinder 21 is coupled to frame 12 and
supports ground engaging blade 16 in the vertical direction, and
allows ground engaging blade 16 to move up or down vertically from
the point of view of FIG. 1. A pair of pitch hydraulic cylinders 22
on each side of machine 10 (FIG. 2) allow the pitch angle of blade
tip 18 to change relative to an axis or centerline of the machine
("CL" in FIG. 1). Actuating the pitch hydraulic cylinders 22 in
opposite directions may permit the ground engaging blade 16 to
rotate or tilt relative to the machine 10. In other words,
operating the pitch hydraulic cylinders 22 in this manner will
permit the rotation of the ground engaging blade 16 generally about
an attachment point of the ground engaging blade to the machine 10
so that opposite corners 19 of the bottom edge of the blade may be
disposed at different heights relative to the ground. The machine
of FIG. 2 depicts an alternate manner of affecting the rotation of
ground engaging blade 16 by utilizing a tilt hydraulic cylinder 23.
Each of the hydraulic cylinders may be electrically controlled and
receive signals from a controller 30. Controller 30 generates a
signal that may be translated into a direction and magnitude of
movement of the appropriate hydraulic cylinders as will be
understood by those skilled in the art.
[0015] Machine 10 includes cab 28 from which an operator may
provide input to control machine 10. Cab 28 includes one or more
controls with which the operator may issue commands. FIG. 1 shows a
joystick 27 from which an operator may control one or more machine
implements, such as ground engaging blade 16. Joystick 27 may be
configured to automatically return to a "neutral" position if the
operator is not moving joystick 27. The operator may move joystick
27 to either side to control the tilt or rotation of ground
engaging blade 16 relative to machine 10. Joystick 27 may operate
as part of a control system of machine 10 wherein the operator's
movement of joystick 27 (including the magnitude of the movement of
joystick 27) is translated into a signal and sent to a controller
30. Movement of joystick 27 generates a signal to controller 30
indicative of the magnitude and direction of the operator's
movement of the joystick. As described in more detail below, the
controller 30 may process the signal and potentially adjust the
signal prior to issuing or generating a command signal to the tilt
hydraulic cylinder 23 to adjust the cross slope or angular
orientation of ground engaging blade 16.
[0016] Machine 10 may be equipped with a plurality of sensors that
provide data indicative (directly or indirectly) of the performance
or operating conditions of various aspects of the machine. A sensor
34 such as a roll rate sensor (e.g., a gyroscope) may be provided
on the ground engaging blade 16 of machine 10. The sensor 34 may be
used to provide a roll rate signal indicative of a measured roll
rate of the ground engaging blade 16. The measured roll rate is the
angular velocity or rate of change of the ground engaging blade 16
as it rotates about the axis of the machine. In other words, as the
tilt hydraulic cylinder 23 causes ground engaging blade 16 to
rotate about an attachment point, the measured roll rate will be
indicative of the velocity or rate of change of the position of the
blade.
[0017] As described in more detail below, controller 30 may utilize
the measured roll rate from sensor 34 to determine that a change is
occurring in the cross slope of ground engaging blade 16.
Controller 30 may perform various functions such as filtering and
scaling the roll rate signal so as to provide a signal indicative
of the rate of change of the angular position or cross slope of the
ground engaging blade 16. The measured roll rate may then be used
to determine whether and how the cross slope angular position of
the ground engaging blade 16 should be adjusted.
[0018] A control system may be provided to control the operation of
the machine 10 including the cross slope control aspects of the
system. The control system may include an electronic control module
such as controller 30. The controller 30 may receive operator input
command signals and control the operation of the hydraulic systems
that operate the various hydraulic cylinders. The controller 30 may
be mounted at any convenient location on machine 10. The control
system may include one or more input devices such as joystick 27 to
control the machine 10 and one or more sensors, including sensor
34, to provide data and other input signals representative of
various operating parameters of the machine 10. A portion of the
control system may operate as cross slope control system to control
the cross slope of the ground engaging blade 16.
[0019] The controller 30 may be an electronic controller that
operates in a logical fashion to perform operations, execute
control algorithms, store and retrieve data and other desired
operations. The controller 30 may include or access memory,
secondary storage devices, processors, and any other components for
running an application. The memory and secondary storage devices
may be in the form of read-only memory (ROM) or random access
memory (RAM) or integrated circuitry that is accessible by the
controller. Various other circuits may be associated with the
controller such as power supply circuitry, signal conditioning
circuitry, driver circuitry, and other types of circuitry.
[0020] The controller 30 may be a single controller or may include
more than one controller disposed to control various functions
and/or features of the machine 10. The term "controller" is meant
to be used in its broadest sense to include one or more controllers
and/or microprocessors that may be associated with the machine 10
and that may cooperate in controlling various functions and
operations of the machine. The functionality of the controller 30
may be implemented in hardware and/or software without regard to
the functionality employed. The controller 30 may rely on one or
more data maps relating to the operating conditions of the machine
10 that may be stored in the memory of controller. Each of these
maps may include a collection of data in the form of tables,
graphs, and/or equations. The controller 30 may use the data maps
to maximize the efficiency of the machine 10.
[0021] Referring to FIG. 3, a flow chart of the operation of the
cross slope control system is depicted. The cross slope control
system may be started automatically upon the start up of machine 10
at stage 41. At decision stage 42, the controller 30 may determine
whether certain predetermined threshold conditions have been met to
activate the cross slope control system. One threshold condition
may be that the machine transmission (not shown) is in a certain
state (e.g., not in neutral). Another example of a threshold
condition may be that the machine ground speed is above or below a
threshold amount or that the engine speed is within a predetermined
range. Still another threshold condition may be that one or more
other control systems are not active in controlling the implement.
This type of condition may be desirable if the machine is equipped
with multiple different implement control systems that are mutually
exclusive and therefore cannot operate together. Another threshold
condition may be based upon the receipt of predetermined steering
commands. For example, the controller may turn off the cross slope
control system during certain turning operations. Other threshold
conditions may be set as desired. It should be noted that the
determination of whether the threshold conditions have been met may
be based upon monitoring the operating characteristics of aspects
of the machine 10 for a particular period. In addition, different
time periods may apply to different threshold conditions.
[0022] If the system threshold conditions are not met at decision
stage 42, the controller 30 will generate at stage 43 a command
signal approximately equal to a roll rate command issued by the
operator. In other words, the controller will not implement the
functionality of the cross slope control system and a command
signal approximately equal to the operator roll rate command will
be transmitted at stage 44 to the control system to control the
position of ground engaging blade 16. If the system threshold
conditions have been met at stage 42, the controller receives the
roll rate signal from the sensor 34 at stage 45. At stage 46, the
controller 30 receives an operator roll rate command reflective of
a desired movement of the ground engaging blade 16 based upon an
input from joystick 27.
[0023] At decision stage 47, the controller determines whether the
operator roll rate command is within an expected range. A command
within an expected range might be one that is within a
predetermined rate (e.g., 2 degrees per second) or within a
predetermined percentage (e.g., 150%) of a target (e.g., the
measured roll rate that is detected by the sensor 34). Other
expected ranges, calculations and targets or references may be set
as desired. In one example, as machine 10 moves along uneven
terrain, sensor 34 will provide a signal indicative of a change in
roll rate (e.g., a change in roll rate of +3 degrees per second).
An operator may attempt to manually compensate for the change in
roll rate by issuing a roll rate command in an opposite direction
(e.g., -2 degrees per second). In such example, the controller 30
may be configured to read the difference between the operator roll
rate command and the measured roll rate as if the operator roll
rate command is within the expected range.
[0024] If the operator command is not within the expected range,
the controller 30 may be configured to generate at stage 48 a
command generally equal to the operator roll rate command. The
command signal generated by the controller 30 is transmitted at
stage 44 to the electro-hydraulic system to control the movement of
the ground engaging blade 16. As an example, if the machine 10
undergoes a change in position such that sensor 34 provides a roll
rate signal indicating a measured roll rate of +1.5 degrees per
second and the operator issues an operator roll rate command of +5
degrees per second, the controller 30 may be configured to respond
to such actions as if the operator intended to change the cross
slope of the ground engaging blade 16 rather than merely attempting
to compensate for the change of machine position. In such example,
the controller 30 will generate a command signal at stage 48
approximately equal to the operator roll rate command, or +5
degrees.
[0025] If the operator roll rate command is within the expected
range at decision stage 47, the controller generates at stage 51 a
command signal based upon the roll rate signal received at stage 45
from sensor 34 and the operator roll rate command received at stage
46. The controller logic may be configured so that the cross slope
control system attempts to maintain the current operating
conditions (e.g., maintain the roll rate signal generally equal to
a velocity of 0) and respond as if changes made by the operator
were intended to compensate for the changes in the roll rate of the
ground engaging blade 16. In other words, the controller 30 may
generate a command signal to move the ground engaging blade 16 in a
direction so as to compensate for movement reported by sensor 34.
The controller 30 may utilize a roll rate command from the operator
as part of the input when generating the command signal. Using the
example above in which the sensor 34 indicated a measured roll rate
of +3 degrees per second and the operator issued an operator roll
rate command of -2 degrees per second, the controller 30 may
generate at stage 51 a command of approximately -1 degree per
second. Depending upon the measured roll rate and the operator roll
rate command, the command signal generated by the controller 30 may
move the ground engaging blade in a direction generally identical
to a direction commanded by the operator roll rate command signal
or in a direction generally opposite to the direction commanded by
the operator roll rate command signal.
[0026] At stage 52, the controller 30 determines whether the ground
engaging blade 16 is at or near its maximum travel position. In
other words, the controller determines whether the command signals
generated at stage 51 will cause the tilt hydraulic cylinder 23 to
reach its maximum travel position and cause the ground engaging
blade 16 to reach its maximum cross slope position. If the tilt
hydraulic cylinder 23 has or will reach its maximum travel position
based upon the signal generated at stage 51, the controller will
modify at stage 54 the command signal to generate a modified
command signal to limit the travel of the tilt hydraulic cylinder
23 and prevent movement of the ground engaging blade 16 past its
predetermined maximum displacement. As such, the ground engaging
blade 16 will be maintained within its operating parameters and not
exceed its maximum travel position. This modified command signal is
transmitted at stage 44 to control the tilt hydraulic cylinder
23.
[0027] If the ground engaging blade 16 is not at or near its
maximum travel position at decision stage 52, the controller does
not change the generated command signal at stage 53. The command
signal is transmitted at stage 44 to control movement of the ground
engaging blade 16.
[0028] It should be noted that even when the operator is not
issuing a roll rate command, the controller will be receiving at
stage 46 an operator roll rate command equal to 0. In most cases,
this operator roll rate command will be within the expected range
at decision stage 47 and the controller will generate at stage 51 a
command signal based upon the measured roll rate and the operator
roll rate command equal to 0. As such, the command signal may be
generated based primarily on the measured roll rate received at
stage 45.
INDUSTRIAL APPLICABILITY
[0029] The industrial applicability of the system described herein
will be readily appreciated from the foregoing discussion. The
foregoing discussion is applicable to machines 10 that utilize an
implement such as a ground engaging blade 16 for which it is
desirable to control its angular orientation or cross slope. In one
aspect, a control system for automated movement of a ground
engaging blade 16 of a machine 10 includes a sensor 34 and a
controller 30. The ground engaging blade 16 is configured for
rotational movement. The sensor 34 is on the ground engaging blade
16 and is configured to provide a roll rate signal indicative of a
measured roll rate of the ground engaging blade. The controller 30
is configured to receive the roll rate signal, receive an operator
roll rate command signal, generate a command signal based at least
in part on the roll rate signal and the operator roll rate command
signal, and transmit the command signal to control movement of the
ground engaging blade 16.
[0030] In another aspect, a controller implemented method of
adjusting a ground engaging blade 16 of a machine 10 is provided.
The ground engaging blade 16 has a sensor 34 configured to provide
a roll rate signal indicative of a measured roll rate of the ground
engaging blade. The method includes receiving the roll rate signal
within a controller 30, receiving an operator roll rate command
signal within the controller 30, generating a command signal within
the controller 30 based at least in part on the roll rate signal
and the operator roll rate command signal, and transmitting the
command signal from the controller 30 to control movement of the
ground engaging blade 16.
[0031] In another aspect, a machine 10 includes a ground engaging
blade 16, a sensor 34 on the ground engaging blade configured to
provide a roll rate signal indicative of a measured roll rate of
the ground engaging blade, and a controller 30. The controller 30
is configured to receive the roll rate signal, receive an operator
roll rate command signal, generate a command signal based at least
in part on the roll rate signal and the operator roll rate command
signal, and transmit the command signal to control movement of the
ground engaging blade 16.
[0032] It will be appreciated that the foregoing description
provides examples of the disclosed system and technique. However,
it is contemplated that other implementations of the disclosure may
differ in detail from the foregoing examples. For example, the
disclosed system may employ a roll rate sensor that is already
disposed on the blade for use in other control functions. That is,
other sensors may be employed to determine the roll rate of the
ground engaging blade that may then be used to determine a command
signal to control the ground engaging blade. All references to the
disclosure or examples thereof are intended to reference the
particular example being discussed at that point and are not
intended to imply any limitation as to the scope of the disclosure
more generally. All language of distinction and disparagement with
respect to certain features is intended to indicate a lack of
preference for those features, but not to exclude such from the
scope of the disclosure entirely unless otherwise indicated.
[0033] Recitation of ranges of values herein are merely intended to
serve as a shorthand method of referring individually to each
separate value falling within the range, unless otherwise indicated
herein, and each separate value is incorporated into the
specification as if it were individually recited herein. All
methods described herein can be performed in any suitable order
unless otherwise indicated herein or otherwise clearly contradicted
by context.
[0034] Accordingly, this disclosure includes all modifications and
equivalents of the subject matter recited in the claims appended
hereto as permitted by applicable law. Moreover, any combination of
the above-described elements in all possible variations thereof is
encompassed by the disclosure unless otherwise indicated herein or
otherwise clearly contradicted by context.
* * * * *