U.S. patent application number 15/188591 was filed with the patent office on 2016-10-13 for system and method for machine control.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Eric W. Cler, Nathan R. Fogg, Scott A. McGregor, Darren M. Schambach, Andrew N. Schifferer, Aaron R. Shatters.
Application Number | 20160298314 15/188591 |
Document ID | / |
Family ID | 57111281 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160298314 |
Kind Code |
A1 |
Fogg; Nathan R. ; et
al. |
October 13, 2016 |
SYSTEM AND METHOD FOR MACHINE CONTROL
Abstract
A system for controlling operations of a machine is provided. A
first sensor module generates a signal indicative of an operator
command and a second sensor module is configured to generate a
signal indicative of a current loading ratio associated with a load
arm assembly of the machine. A control module is communicably
coupled to the first sensor module and the second sensor module to
receive a signal indicative of a current operating mode of the
machine, and further to receive the signal indicative of the
operator command and the signal indicative of the current loading
ratio associated with the load arm assembly of the machine.
Further, the control module compares the current loading ratio with
a pre-determined load rating of the machine, and selectively limits
an action associated with the operator command based on the
comparison and the current operating mode of the machine.
Inventors: |
Fogg; Nathan R.;
(Naperville, IL) ; Schambach; Darren M.; (Batavia,
IL) ; Schifferer; Andrew N.; (Batavia, IL) ;
Cler; Eric W.; (Oswego, IL) ; Shatters; Aaron R.;
(Montgomery, IL) ; McGregor; Scott A.; (Aurora,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Peoria |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Peoria
IL
|
Family ID: |
57111281 |
Appl. No.: |
15/188591 |
Filed: |
June 21, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01G 19/083 20130101;
B66F 17/00 20130101; B66F 17/003 20130101; E02F 3/422 20130101;
E02F 9/2029 20130101; E02F 3/34 20130101 |
International
Class: |
E02F 9/20 20060101
E02F009/20; E02F 9/22 20060101 E02F009/22 |
Claims
1. A system for controlling operations of a machine, the system
comprising: a first sensor module configured to generate a signal
indicative of an operator command; a second sensor module
configured to generate a signal indicative of a current loading
ratio associated with a load arm assembly of the machine; and a
control module communicably coupled to the first sensor module and
the second sensor module, the control module configured to: receive
a signal indicative of a current operating mode of the machine;
receive the signal indicative of the operator command and the
signal indicative of the current loading ratio associated with the
load arm assembly of the machine; compare the current loading ratio
with a pre-determined load rating of the machine; and selectively
limit an action associated with the operator command based on the
comparison and the current operating mode of the machine.
2. The system of claim 1, wherein the operator command includes at
least one of a lift command, and a tilt command.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to controlling an operation
of a machine.
BACKGROUND
[0002] Machines are employed for a variety of tasks in
construction, mining and/or other applications. These machines
include, but are not limited to, skid steer loaders, wheel loaders,
backhoe loaders, forklifts, and compact track loaders. For example,
the wheel loader includes a work tool that may be raised and
lowered based on inputs from an operator. The work tool is
connected to a stick and boom assembly for loading and unloading
materials, such as dirt, sand, or gravel and moving the material
from one place to another.
[0003] During operations, the machine may experience dynamic
events. The dynamic events may occur when the machine is operated
beyond its operating capability or conditions where the machine is
subjected to rapid change in material loads or sudden movement.
Conventional techniques for improving stability of the machine are
based on a static center-of-gravity (CG) analysis. However, such
techniques may not efficiently stabilize the machine, when the
loaded material is particularly heavy. As a consequence, there are
chances of strain or stress on various components, such as a frame
of the machine. As a result, the machine suffers from increased
down-time and maintenance costs.
[0004] U.S. Published Application Number 2010/0204891 describes a
control system for a vehicle having a loader arm, such as a skid
steer loader, telescopic handler, wheel loader, backhoe loader or
forklift. The vehicle may include an electronic control system
capable of electronically monitoring the skid steer loader's load,
the height of that load, and of responsively derating or reducing
the drive system's response to operator commands. The electronic
control system combines these sensor signals and, by dynamically
and continuously calculating if the drive system needs derating and
a magnitude by which this control may need to be exercised. The
electronic control system generates a signal to limit the
acceleration of the vehicle to less than the dynamically calculated
acceleration necessary to cause the dynamic center of gravity of
the combined vehicle and load to extend exterior of an edge of the
stability polygon for the vehicle.
SUMMARY OF THE DISCLOSURE
[0005] In one aspect of the present disclosure, a system for
controlling operations of a machine is provided. The system
includes a first sensor module, a second sensor module, and a
control module. The first sensor module is configured to generate a
signal indicative of an operator command. The second sensor module
is configured to generate a signal indicative of a current loading
ratio associated with a load arm assembly of the machine. The
control module is communicably coupled to the first sensor module
and the second sensor module. The control module is configured to
receive a signal indicative of a current operating mode of the
machine. The control module is configured to receive the signal
indicative of the operator command and the signal indicative of the
current loading ratio associated with the load arm assembly of the
machine. The control module is configured to compare the current
loading ratio with a pre-determined load rating of the machine. The
control module is configured to selectively limit an action
associated with the operator command based on the comparison and
the current operating mode of the machine.
[0006] Other features and aspects of this disclosure will be
apparent from the following description and the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of an exemplary machine, in
accordance with the concepts of the present disclosure; and
[0008] FIG. 2 is a block diagram of a system for controlling an
operation of the machine.
DETAILED DESCRIPTION
[0009] Referring to FIG. 1, an exemplary machine 10 is illustrated.
The machine 10 shown in FIG. 1 is a wheel loader. The machine 10 is
used for loading and unloading of various types of materials, such
as stones, marble in block form and also earthen material. The
machine 10 includes a load arm assembly 12 that further includes a
work tool 14 utilized for carrying the materials. The work tool 14
maybe a bucket, a fork, a material handling arm, or any other
handling equipments. The load arm assembly 12 is mounted to a frame
16 of the machine 10, and further includes booms 18 coupled to the
work tool 14. The booms 18 are used to lift the work tool 14 to
carry out various operations. The machine 10 further includes a
hydraulic cylinder 20 coupled to a bellcrank 22. The bellcrank 22
is further coupled to the booms 18 using a connecting member 24 and
a linkage 26. The bellcrank 22 is also coupled to a bellcrank bar
28, disposed between the booms 18, via a pivot joint (not shown).
The bellcrank bar 28 couples the work tool 14 to the bellcrank 22,
thus enabling an orientation of the work tool 14 to be varied by
retracting and expanding the hydraulic cylinder 20. Alternatively,
structure of the load arm assembly 12 of the machine 10 may vary
from one machine to another, and therefore, number of hydraulic
cylinders and other components may vary depending on type of the
machine 10.
[0010] The machine 10 further includes an operator cabin 30 and a
seat 32. An operator sits on the seat 32 in the operator cabin 30
for controlling various operations of the machine 10 such as
loading and unloading of various types of materials. Further, the
machine 10 includes an engine 34 and a number of wheels 36. The
engine 34 provides power to the machine 10 for carrying out various
operations. The operator controls and monitors operating parameters
of the machine 10 via input and/or output modules. The input and/or
output modules may include a display device, a camera, a steering
wheel, a speaker, a joystick or other input and/or output devices.
The machine 10 is used for various operations such as, but not
limited to, grading of land, or loading, or transportation of
materials, among others. The machine 10 may be any other wheeled
machine including, but not limited to, a track loader, a wheel
dozer, an excavator, or any other suitable machine, without
departing from the scope of the disclosure.
[0011] Referring to FIG. 2, a system 38 for controlling operations
of the machine 10 is illustrated. The system 38 includes a first
sensor module 40 and a second sensor module 42. The first sensor
module 40 is configured to generate a signal indicative of an
operator command. In an exemplary embodiment, the first sensor
module 40 may be a joystick position sensor that uses a rotary
potentiometer to produce an electrical signal in response to a
pivotal position of a control lever as operated by the operator.
When the operator moves the control lever, the electrical signal is
generated that is indicative of the operator command.
[0012] In one example, the operator command is associated with
operations performed on or using the load arm assembly 12 of the
machine 10. These operations are related to loading and unloading
of the material from the machine 10. Examples of the operator
command may include, but are not limited to, a lift command and a
tilt command. The lift command is used to raise or lower the work
tool 14. The tilt command is used for tilting the work tool 14 for
the racking/dumping operations. The first sensor module 40 may be
an eddy-current sensor, a hall-effect sensor or a proximity sensor,
among others. Also, the first sensor module 40 may include various
sensors, such as sensors located on a steering, a joystick, or any
other components of the machine 10. In another example, the
operator command is associated with other activities of the machine
10, such as speed, heading, etc.
[0013] The second sensor module 42 is configured to generate a
signal indicative of a current loading ratio associated with the
load arm assembly 12 of the machine 10. The loading ratio is
indicative of a current load present on the machine 10 with respect
to a total load that the machine 10 is capable of handling. The
loading ratio is calculated from operating values received from a
head end (not shown) and a rod end (not shown) of the hydraulic
cylinder 20. Alternatively, the loading ratio may also he
calculated using strain gauges, other instruments or any other
mechanism without departing from the disclosure. The second sensor
module 42 may include strain gauges, pressure sensors, or any other
sensor. Also, the second sensor module 42 may include various other
sensors, such as sensors located on the hydraulic cylinder 20, the
load arm assembly 12, or any other components within the machine
10.
[0014] Referring to FIG. 2, a control module 44 is communicably
coupled with the first sensor module 40 and the second sensor
module 42. The control module 44 is configured to receive a signal
indicative of a current operating mode of the machine 10. The
operating modes may be a "dig state" or any other operating mode
hereinafter referred as a "non-dig state". The term "dig state"
refers to a state in which the machine 10 is performing a digging
operation. Alternatively, the term "non-dig state" refers to a
state in which the machine 10 is performing operations other than
digging operation, such as material handling and transportation,
etc. The signal indicative of the current operating mode may be
received from a third sensor module (not shown). Alternatively, the
signal indicative of the current operating mode may he input by the
operator.
[0015] The control module 44 receives the signal indicative of the
operator command from the first sensor module 40. Further, the
control module 44 receives the signal indicative of the current
loading ratio associated with the load arm assembly 12 of the
machine 10. The control module 44 is communicably coupled with a
database 46 that stores a pre-determined load rating of the machine
10. The control module 44 compares the current loading ratio with
the pre-determined load rating.
[0016] The control module 44 may further limit an action associated
with the operator commands based on the comparison and the current
operating mode of the machine 10. Based on the comparison between
the current loading ratio with the pre-determined load rating, the
control module 44 limits the action associated with the operator
command, such as the lift command and the tilt command. As an
example, the control module 44 may variably limit an action
associated with the operator command, for example the action may
include movements of the load aim assembly 12 of the machine 10.
The control module 44 may control the operating parameters of the
machine 10 within the permissible range. For example, if the
current loading ratio is less than the pre-determined load rating,
then the command and parameters associated with the lift command
are unaltered. Else, if the current loading ratio is more than the
pre-determined load rating, then the control module 44 is
configured to limit the command and parameters associated with the
lift command.
[0017] As an example, a low pass filter (LPF) or any other logic
may he used for limiting the action of the operator command. The
control module 44 is configured to limit a magnitude and/or rate of
application of the action of the operator command. For example, the
control module 44 may be configured to change a pressure of the
hydraulic cylinder 20 from 100% to 60% to limit an action
associated with the lift command of the work tool 14. Further, the
control module 44 may also be configured to change the rate of
application by increasing a time for executing the command from
0.25 seconds to 4.0 seconds for limiting the action associated with
the lift command of the work tool 14. Alternatively, the control
module 44 may also he configured to change the magnitude as well as
rate of application in other possible combinations to limit the
action associated with the lift command.
[0018] In other embodiments, the signals from the first sensor
module 40 and the second sensor module 42 may be received or
interpreted by the control module 44 only when the control module
44 has determined that the machine 10 is operating in the non-dig
state. In another embodiment, the signals from the first sensor
module 40 and the second sensor module 42 may be continuously
received, but the comparison of the loading ratio with the
pre-determined load rating may take place after the control module
44 has determined that the machine 10 is operating in the non-dig
state.
[0019] The database 46 includes a memory for storing the
pre-determined load rating. The pre-determined load rating may be
calculated on the basis of historical data and defines a range of
operating the machine 10 within permissible limit. The
pre-determined load rating may contain readings of pre-estimated
load values during various operating conditions associated with the
machine 10. The database 46 includes look-up tables for storing the
pre-determined load rating of the machine 10. The database 46 may
be any conventional or non-conventional database known in the art.
In one embodiment, the database 46 may be extrinsic to the machine
10 and located at a remote location away from the machine 10.
Alternatively, the database 46 may be intrinsic to the machine
10.
[0020] The control module 44 is an electronic controller that is
remotely coupled with an engine control module (ECM) of the engine
34 for carrying out various operations. The control module 44 may
be a logic unit using any one or more of a processor, a
microprocessor, and a microcontroller. The control module 44 may be
based on an integrated circuitry, discrete components, or a
combination of the two. Further, other peripheral circuitry, such
as buffers, latches, switches, and the like may be implemented
within the control module 44 or separately connected to the control
module 44. It will be apparent to one skilled in the art that the
control module 44 mentioned above may be an individual component
which is in communication with other circuitries of the system 38.
The control module 44 may be networked over a serial communication
bus such as a controller area network (CAN) bus (not shown). Other
arrangements of microcontrollers and microprocessors may be used.
There may be several sensors connected to the control module 44
that provide the electronic controller with data for various
operating conditions.
INDUSTRIAL APPLICABILITY
[0021] The system 38 controls dynamic events in the machine 10 by
limiting operator action by magnitude control or rate of change
control. The dynamic events may occur when the machine 10 is
operated beyond its operating capability or conditions where the
machine 10 is subjected to rapid change in material loads or sudden
movement. The control module 44 may variably limit the action
associated with the operator command, for example, the action may
include movements of the load arm assembly 12 of the machine 10.
The control module 44 may control the operating parameters of the
machine 10 within the permissible range.
[0022] The system 38 is also applicable to the control other
implements used on other machines, such as wheel type loaders,
track type loaders, hydraulic excavators, backhoes, and similar
vehicles having hydraulically operated implements. The system 38
controls the operation of the machine 10 by restricting the
operator commands on the basis of loading ratio. The system 38
offers reliable operations, controls the machine 10 and also
extends service life of components of the machine 10.
[0023] 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.
* * * * *