U.S. patent application number 14/577845 was filed with the patent office on 2015-04-16 for variable-speed irrigation system.
The applicant listed for this patent is Valmont Industries, Inc.. Invention is credited to Craig S. Malsam.
Application Number | 20150102136 14/577845 |
Document ID | / |
Family ID | 47506969 |
Filed Date | 2015-04-16 |
United States Patent
Application |
20150102136 |
Kind Code |
A1 |
Malsam; Craig S. |
April 16, 2015 |
VARIABLE-SPEED IRRIGATION SYSTEM
Abstract
An irrigation system is disclosed that is configured to maintain
a near straight alignment. In an implementation, an irrigation
system includes multiple interconnected spans which are supported
by multiple tower structures. Each tower structure includes a
variable-speed drive unit for selectively driving a tower structure
at a selected speed. The irrigation system also includes multiple
sensors that are each associated with a corresponding span to
determine an alignment of the corresponding span with respect to
adjacent spans. Each of the sensors is in communication with a
corresponding variable-drive control unit. Each of the
variable-drive control units are configured to control the selected
speed of a corresponding variable-speed drive unit to maintain the
interconnected spans in a substantially linear orientation with
respect to adjacent ones of the plurality of interconnected spans
along a generally longitudinally oriented axis (e.g., maintain
alignment of the spans with respect to each other).
Inventors: |
Malsam; Craig S.; (Omaha,
NE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Valmont Industries, Inc. |
Omaha |
NE |
US |
|
|
Family ID: |
47506969 |
Appl. No.: |
14/577845 |
Filed: |
December 19, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13549439 |
Jul 14, 2012 |
8948979 |
|
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14577845 |
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|
61507693 |
Jul 14, 2011 |
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Current U.S.
Class: |
239/731 ;
239/733 |
Current CPC
Class: |
B05B 15/658 20180201;
A01G 25/092 20130101; A01G 25/16 20130101 |
Class at
Publication: |
239/731 ;
239/733 |
International
Class: |
A01G 25/16 20060101
A01G025/16; A01G 25/09 20060101 A01G025/09 |
Claims
1. An irrigation system comprising: a plurality of interconnected
spans; a plurality of tower structures for supporting the
interconnected spans, each one of the plurality of tower structures
including a variable-speed drive unit for selectively driving a
tower structure at a selected speed; a plurality of sensors, each
one of the plurality of sensors associated with a corresponding one
of the plurality of interconnected spans and configured to
determine an alignment of a corresponding one of the plurality of
interconnected spans; and a plurality of variable-drive control
units, each variable-drive control unit of the plurality of drive
control units in communication with a corresponding variable-speed
drive unit and a corresponding sensor, each variable-drive control
unit configured to control the selected speed of the corresponding
variable-speed drive unit to maintain the plurality of
interconnected spans in a substantially linear orientation with
respect to adjacent ones of the plurality of interconnected spans
along a generally longitudinally oriented axis, wherein the
selected speed of the corresponding variable-drive control unit is
based upon the alignment.
2. The irrigation system as recited in claim 1, wherein at least
one sensor is configured to determine an angle between a first
corresponding interconnected span of the plurality of
interconnected spans and a second corresponding interconnected span
of the plurality of interconnected spans; wherein the corresponding
variable-drive control unit is configured to determine a selected
speed to maintain the plurality of interconnected spans in a
substantially linear orientation with respect to adjacent ones of
the plurality of interconnected spans along a generally
longitudinally oriented axis, the selected speed based upon the
angle.
3. The irrigation system as recited in claim 1, wherein each sensor
of the plurality of sensors is in direct communication with a
corresponding variable-drive control unit of the plurality of
variable-drive control units.
4. The irrigation system as recited in claim 1, wherein the
variable-speed drive units comprise switched reluctance motors.
5. The irrigation system as recited in claim 1, wherein the
plurality of sensors comprise at least one of a potentiometer, a
captive alignment sensor, a laser based alignment sensor, or a
non-contact proximity sensor.
6. The irrigation system as recited in claim 1, wherein at least
one sensor of the plurality of sensors is configured to
continuously furnish a signal to the corresponding variable-drive
control unit, wherein the variable-drive control unit is configured
to continuously furnish a signal to a variable-drive unit of the
corresponding interconnected span to continuously modify a speed of
the corresponding tower structure to re-align the corresponding
tower structure with the adjacent tower structure.
7. An irrigation system comprising: a center pivot structure; a
main section assembly coupled to the center pivot structure, the
main section assembly including a plurality of interconnected
spans; a plurality of tower structures for supporting the
interconnected spans, each one of the plurality of tower structures
including a variable-speed drive unit for selectively driving a
tower structure at a selected speed; a plurality of sensors, each
one of the plurality of sensors associated with a corresponding one
of the plurality of interconnected spans and configured to
determine an alignment of a corresponding one of the plurality of
interconnected spans; a plurality of variable-drive control units,
each variable-drive control unit of the plurality of drive control
units in communication with a corresponding variable-speed drive
unit and a corresponding sensor, each variable-drive control unit
configured to control the selected speed of the corresponding
variable-speed drive unit to maintain the plurality of
interconnected spans in a substantially linear orientation with
respect to adjacent ones of the plurality of interconnected spans
along a generally longitudinally oriented axis, wherein the
selected speed of the corresponding variable-drive control unit is
based upon the alignment.
8. The irrigation system as recited in claim 7, wherein at least
one sensor is configured to determine an angle between a first
corresponding interconnected span of the plurality of
interconnected spans and a second corresponding interconnected span
of the plurality of interconnected spans; wherein the corresponding
variable-drive control unit is configured to determine a selected
speed to maintain the plurality of interconnected spans in a
substantially linear orientation with respect to adjacent ones of
the plurality of interconnected spans along a generally
longitudinally oriented axis, the selected speed based upon the
angle.
9. The irrigation system as recited in claim 7, wherein each sensor
of the plurality of sensors is in direct communication with a
corresponding variable-drive control unit of the plurality of
variable-drive control units.
10. The irrigation system as recited in claim 7, wherein the
variable-speed drive units comprise switched reluctance motors.
11. The irrigation system as recited in claim 7, wherein the
plurality of sensors comprise at least one of a potentiometer, a
captive alignment sensor, a laser based alignment sensor, or a
non-contact proximity sensor.
12. The irrigation system as recited in claim 7, wherein at least
one sensor of the plurality of sensors is configured to
continuously furnish a signal to the corresponding variable-drive
control unit, wherein the variable-drive control unit is configured
to continuously furnish a signal to a variable-drive unit of the
corresponding interconnected span to continuously modify a speed of
the corresponding tower structure to re-align the corresponding
tower structure with the adjacent tower structure.
13. An irrigation system comprising: a center pivot structure; a
main section assembly coupled to the center pivot structure, the
main section assembly including a plurality of interconnected
spans; a plurality of tower structures for supporting the
interconnected spans, each one of the plurality of tower structures
including a switched reluctance motor for selectively driving a
tower structure at a selected speed; a plurality of sensors, each
one of the plurality of sensors associated with a corresponding one
of the plurality of interconnected spans and configured to
determine an alignment of a corresponding one of the plurality of
interconnected spans; a plurality of variable-drive control units,
each variable-drive control unit of the plurality of drive control
units in communication with a corresponding variable-speed drive
unit and a corresponding sensor, each variable-drive control unit
configured to control the selected speed of the corresponding
switched reluctance motor to maintain the plurality of
interconnected spans in a substantially linear orientation with
respect to adjacent ones of the plurality of interconnected spans
along a generally longitudinally oriented axis, wherein the
selected speed of the corresponding variable-drive control unit is
based upon the alignment.
14. The irrigation system as recited in claim 13, wherein at least
one sensor is configured to determine an angle between a first
corresponding interconnected span of the plurality of
interconnected spans and a second corresponding interconnected span
of the plurality of interconnected spans; wherein the corresponding
variable-drive control unit is configured to determine a selected
speed to maintain the plurality of interconnected spans in a
substantially linear orientation with respect to adjacent ones of
the plurality of interconnected spans along a generally
longitudinally oriented axis, the selected speed based upon the
angle.
15. The irrigation system as recited in claim 13, wherein each
sensor of the plurality of sensors is in direct communication with
a corresponding variable-drive control unit of the plurality of
variable-drive control units.
16. The irrigation system as recited in claim 13, wherein the
plurality of sensors comprise at least one of a potentiometer, a
captive alignment sensor, a laser based alignment sensor, or a
non-contact proximity sensor.
17. The irrigation system as recited in claim 15, wherein at least
one sensor of the plurality of sensors is configured to
continuously furnish a signal to the corresponding variable-drive
control unit, wherein the variable-drive control unit is configured
to continuously furnish a signal to a variable-drive unit of the
corresponding interconnected span to continuously modify a speed of
the corresponding tower structure to re-align the corresponding
tower structure with the adjacent tower structure.
Description
BACKGROUND
[0001] Modern day agriculture has become increasingly efficient in
the past century and this trend must continue in order to produce a
sufficient food supply for the increasing world population. A
notable advancement in agricultural production was the introduction
of mechanized irrigation systems, such as the center pivot and the
linear move irrigation systems. These irrigation systems make it
possible to irrigate entire fields, and reduce a crop yield's
vulnerability to extreme weather conditions. The ability to monitor
and to control the amount of water and/or nutrients (applicants)
applied to an agricultural field has increased the amount of
farmable acres in the world and increases the likelihood of a
profitable crop yield. These irrigation systems typically include a
control device configured to furnish a user interface allowing the
operator to monitor and control one or more functions or operations
of the irrigation system.
SUMMARY
[0002] An irrigation system is disclosed that is configured to
maintain a near straight (e.g., an at least zero degree
(0.degree.)) alignment. In an implementation, an irrigation system
includes multiple interconnected spans which are supported by
multiple tower structures. Each tower structure includes a
variable-speed drive unit for selectively driving a tower structure
at a selected speed. In a specific implementation, the
variable-speed drive units may be switched reluctance motors. The
irrigation system also includes multiple sensors that are each
associated with a corresponding span to determine an alignment of
the corresponding span with respect to adjacent spans. Each of the
sensors is in communication with a corresponding variable-drive
control unit. Each of the variable-drive control units are
configured to control the selected speed of a corresponding
variable-speed drive unit to maintain the interconnected spans in a
substantially linear orientation with respect to adjacent ones of
the plurality of interconnected spans along a generally
longitudinally oriented axis (e.g., maintain alignment of the spans
with respect to each other). In a specific implementation, the
variable-drive control units may be in direct communication with
the corresponding sensor.
[0003] This Summary is provided solely to introduce subject matter
that is fully described in the Detailed Description and Drawings.
Accordingly, the Summary should not be considered to describe
essential features nor be used to determine scope of the
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a
reference number identifies the figure in which the reference
number first appears. The use of the same reference numbers in
different instances in the description and the figures may indicate
similar or identical items.
[0005] FIG. 1A is an isometric diagrammatic perspective view of an
irrigation system in accordance with an example implementation of
the present disclosure.
[0006] FIG. 1B is a block diagram illustrating a control device of
the irrigation system shown in FIG. 1A in accordance with an
example implementation of the present disclosure.
[0007] FIG. 1C is a block diagram illustrating a sensor in
electronic communication with a variable-drive control unit,
wherein the variable control device is configured to control the
selected speed of a variable-drive unit based upon an alignment of
corresponding adjacent spans as determined by the sensor.
[0008] FIG. 1D is a block diagram illustrating an example
implementation of a variable-drive control unit that is configured
to control a variable-drive unit, wherein the variable-drive
control unit includes a processor, a memory, and a communication
module configured to communicate with a sensor and the
variable-drive unit.
DETAILED DESCRIPTION
Overview
[0009] Most irrigation systems, such as center pivot irrigation
systems, include drive units (motors) located on the drive towers
to propel the irrigation system. Many of these rely on fixed rate
motors due to their relative simplicity and robustness. However,
such systems can only adjust the relative alignment of various span
portions by alternatively starting and stopping the drives. This
results in drive towers coming to a complete stop and then
requiring a large impulse of power to start the tower again. The
starting and stopping places undue stress on various components of
the irrigation system, which can accelerate wear and increase
maintenance costs. The irregular motion can also cause uneven
application of irrigation water and/or chemicals to the field. This
results in waste of both water and chemicals. The irregular motion
can also cause errors in alignment or in determining the position
of the end of the machine. This can result in errors in operations
based on position.
[0010] Accordingly, an irrigation system is disclosed that is
configured to maintain a near straight (e.g., an at least zero
degree (0.degree.)) alignment. In an implementation, an irrigation
system includes multiple interconnected spans which are supported
by multiple tower structures. Each tower structure includes a
variable-speed drive unit for selectively driving a tower structure
at a selected speed. The irrigation system also includes multiple
sensors that are each associated with a corresponding span to
determine an alignment of the corresponding span with respect to
adjacent spans. Each of the sensors is in communication with a
corresponding variable-drive control unit. Each of the
variable-drive control units are configured to control the selected
speed of a corresponding variable-speed drive unit to maintain the
interconnected spans in a substantially linear orientation with
respect to adjacent ones of the plurality of interconnected spans
along a generally longitudinally oriented axis (e.g., maintain
alignment of the spans with respect to each other).
[0011] Example Implementations
[0012] FIG. 1A illustrates a self-propelled (e.g., mechanized)
irrigation system (assembly) 100 in accordance with example
implementations of the present disclosure. Examples of
self-propelled irrigation systems include a center pivot irrigation
system, a linear move irrigation system, or the like. FIG. 1A
illustrates an embodiment of the present disclosure where the
irrigation system 100 is a center pivot irrigation system. However,
it is contemplated that the present disclosure may be implemented
in other self-propelled irrigation systems (e.g., linear move
irrigation systems). As shown, the system 100 includes a center
pivot structure 102, a main section assembly 104 (irrigation
section assembly) coupled (e.g., connected) to the center pivot
structure 102. The center pivot structure 102 has access to a well,
a water repository (e.g., water tank), or other fluid source, to
furnish water to the irrigation system 100. For instance, the well
may be located under the center pivot structure 102. In another
instance, the well may be in close proximity to the cultivation
area (e.g., field). The fluid source may be coupled to a repository
or other source of agricultural products to inject fertilizers,
pesticides, and/or other chemicals into the fluids to create an
applicant for application during irrigation. Thus, the applicant
may be water, fertilizer, herbicide, pesticide, combinations
thereof, or the like. The irrigation system 100 may be coupled to a
fluid displacement device (e.g., a pump assembly) configured to
furnish applicant throughout the irrigation system 100. For
example, the fluid displacement device may assist in displacing
fluid from the fluid source (e.g., well, water repository, etc.) to
the conduit portions of the irrigation system which are described
herein. The center pivot structure 102 can be fixed or can be
towable such that an operator can move the irrigation system 100
from one field to another. In an implementation, the center pivot
structure 102 may comprise a frame assembly (e.g., galvanized steel
frame assembly, and so forth).
[0013] The main section assembly 104 includes a number of
interconnected spans 106, 108, 109 (e.g., irrigation spans)
supported by one or more tower structures 110, 111 (intermediate
tower structures) and an end tower structure 112. The tower
structures 110, 111, 112 may be any tower configuration known in
the art to adequately support the conduits (e.g., water pipe
sections) described herein. It is understood that the section
assembly 104 may include any number of spans and tower
structures.
[0014] The tower structures 110, 111 and the end tower structure
112 each include wheels 114, 116, to assist in traversing the
irrigation system 100 (e.g., allowing the main section assembly 104
to pivot) about a cultivation area (e.g., field). In an
implementation, the wheels 114, 116 may be driven by a suitable
variable-drive unit 118 (e.g., drive motor), or the like, to assist
in traversing the system 100 about the specified area. For example,
each tower structure 110 may include a drive unit 118 to propel the
respective tower structure 110, 111, 112 (and the irrigation system
100) through the cultivation area. In one or more implementations,
the drive units 118 comprise variable-speed motors that are
configured to selectively drive a tower structure at a selected
speed. For example, the drive units 118 may comprise electric
switched reluctance motors configured to drive the irrigation
system 100 in a forward direction or a reverse direction.
Typically, the alignment between each span 106, 108, 109 (e.g.,
machine alignment) of the irrigation system 100 is maintained by a
suitable mechanical linkage at each drive unit span joint. The
drive unit span joint is configured as a potentiometer, or other
sensor, that serves to accelerate or decelerate the respective
drive unit 118 (switched reluctance motors, which are described in
greater detail below) to at least substantially keep the respective
span 106, 108, 109 in alignment with the other irrigation span.
Alignment may be defined as each span 106, 108, 109 being aligned
with one or more adjacent spans along a generally linear
longitudinal axis (e.g., defined with respect to a generally
horizontal surface, such as the ground).
[0015] As shown in FIG. 1A, each span 106, 108 includes conduits
120, 121, 122 (e.g., pipes) that are configured to carry (e.g.,
transport, provide, and so forth) liquid (e.g., applicant) along
the length of the system 100 to one or more applicant dispersal
assemblies that are configured to irrigate the cultivation area.
Each conduit 120, 121, 122 may be coupled to one another to allow
fluid communication between each conduit. In an implementation, the
conduits 120, 121, 122 may be supported by truss-type framework
structures 124, 125, 126. Thus, the main fluid displacement device
may be configured to displace applicant through the conduits 120,
121, 122. As shown in FIG. 1A, the irrigation system 100 also
includes a cantilevered boom structure 128 that extends outwardly
from the end tower structure 112. In one or more implementations,
the cantilevered boom 128 includes an end gun 129 (e.g., end gun
129 is mounted to the cantilevered boom 128). The end gun 129 may
be a suitable pressure sprayer configured to be activated at the
corners of a field, or other designated areas, to increase the
amount of land that can be irrigated.
[0016] As shown in FIGS. 1A and 1B, the irrigation system 100
includes a control device 130 (e.g., control panel) that is in
electronic communication with one or more components of the system
100. For example, the control device 130 may be in electronic
communication with one or more tower boxes mounted at one or more
tower structures 110, 111, 112, and a position sensor 132 utilized
to determine an approximate position of the irrigation system
(e.g., determining the approximate position of the end tower
structure 112 within the cultivation area with respect to the
center pivot structure 102). In an implementation, the position
sensor 132 may be a GPS sensor (e.g., GPS receiver), or the like,
mounted to the end tower structure 112 configured to transmit
signals representing the position of the end tower structure to the
control device 130. As described herein, the control device 130 is
configured to determine the radial position of the main section
assembly 104 with respect to the center pivot structure 102. In
another implementation, the position sensor 132 may be an angle
sensor 133 configured to facilitate determination of the rotational
position of the main section assembly 104. The angle sensor 133 may
be mounted to the center pivot structure 102 to assist in
determining the rotational position of the main section assembly
104.
[0017] In an implementation, the control device 130 is mounted to
the central pivot structure 102, a control cart, or a tower
structure 110, 111, 112. The control device 130 is generally
located on the structural element of the irrigation system 100
where the applicant/water is introduced into the irrigation system;
however, other configurations known in the art are within the scope
of the present disclosure.
[0018] The control device 130 is configured to monitor operating
conditions and configured to control various functions of the
irrigation system 100. In certain implementations, the control
device 130 actively monitors the irrigation system's 100 function
and performance including, but not limited to: a position of one or
more conduit sections 120, 121, 122 or tower structures 110, 111,
112 (e.g., the position of the main section assembly 104), whether
the irrigation system 100 is powered on or off, a voltage parameter
associated with the irrigation system 100, a motor speed parameter
associated with the irrigation system 100, an approximate ground
speed parameter associated with the irrigation system 100, a
direction parameter associated with the irrigation system 100, a
diagnostic parameter associated with the irrigation system 100,
whether the applicant is being supplied to the irrigation system
100 (e.g., whether the fluid displacement device is operational),
whether the Stop in Slot (SIS) is powered on or off, an applicant
pressure associated with the irrigation system 100, a time
parameter, a date parameter, a field position parameter of the
irrigation system components, end-gun status, and whether the
programs (e.g., software programs, etc.) are running properly. The
control device 130 also controls the irrigation system's 100
functions and settings including, but not limited to: start and
stop, selectively powering the main fluid displacement device, an
applicant application depth parameter, the direction of travel
associated with the irrigation system 100, selectively powering the
SIS, automatically reversing or stopping the irrigation system 100,
automatically restarting the irrigation system 100, providing an
operator auxiliary control to the system 100, writing and editing
irrigation programs (e.g., irrigation software programs), and
controlling sector and sequential programs (e.g., software
programs). In another implementation, the control device 130 may
cause an alert to be issued to the operator if there are any errors
in the operation of the irrigation system 100 or if any of the
functions or conditions monitored by the control device 130 have
been compromised (e.g., ceased operation or are outside an
acceptable range).
[0019] The control device 130 may be housed in a weather-proof box
and, as shown in FIG. 1B, includes at least a memory 134 to store
one or more software programs (e.g., software modules), a processor
136 communicatively coupled to the memory 134, a user interface 138
(e.g., graphical user interface, etc.), and a communications module
140 (e.g., transmitter, receiver, transceiver, etc.). The memory
134 is an example of tangible computer-readable media that provides
storage functionality to store various data associated with the
operation of the control device 130, such as software
programs/modules and code segments mentioned herein, or other data
to instruct the processor 136 to perform the steps described
herein.
[0020] As described above, the irrigation system may include a
plurality of drive units 118 mounted to each tower structure 110,
111, 112. As shown in FIG. 1C, each drive unit 118 may comprise a
switched reluctance motor (SRM) 142. The switched reluctance motor
142 is an electric motor configured to operate utilizing reluctance
torque. The use of switched reluctance motors 142 allows for
continuous speed adjustment (as compared to motors not utilizing
switched reluctance configurations), which allows for dynamic
("on-the-fly") alignment adjustments of the spans 106, 108, 109.
Additionally, the switched reluctance motors 142 allow for the
constant movement of the center pivot irrigation systems (as
compared to center pivot irrigation systems not having switched
reluctance motors), which may allow for greater uniform application
of water and/or chemicals while lessening waste.
[0021] As shown in FIG. 1C, the variable-drive units 118 may each
include a variable-drive control unit 143. As shown in FIG. 1D, the
variable-drive control unit 143 includes a processor 202 is
configured to provide processing functionality to the
variable-drive control unit 143. Thus, the processor 202 may
execute one or more software programs and/or instructions described
herein. The variable-drive control unit 143 also includes a memory
204, which is an example of tangible computer-readable media that
provides storage functionality to store various data associated
with the operation of the variable-drive control unit 143, such as
software programs/modules and code segments mentioned herein, or
other data to instruct the processor 202 to perform the steps
described herein. In an implementation, the variable-drive control
unit 143 is directly connected with the respective sensor 144
(e.g., via a wired connection). In this implementation, the
variable control unit 143 is also directly connected to the
respective switched reluctance motor 142 (e.g., via a wired
connection). In another implementation, the variable-drive control
unit 143 may include a communication module 206, which is
configured to communicate with other components (e.g., switched
reluctance motors 142, sensors 144) over a communication network
(e.g., a wireless network, a wired network, etc.). For example, the
communication module 206 may be directed coupled (e.g., via one or
more wires, or the like) to a corresponding variable-drive unit
118, as well as a corresponding sensor 144. The communication
module 206 may be representative of a variety of communication
components and functionality, including, but not limited to: one or
more antennas, a transmitter and/or receiver, a transceiver, or the
like. While FIG. 1D illustrates that the variable-drive control
unit 143 is integrated (e.g., housed within) with the
variable-drive unit 118, it is understood that the variable-drive
control unit 143 may be a standalone unit.
[0022] As shown in FIG. 1C, each of the sensors 144 is in
communication with the respective variable-drive control unit 143.
In a specific implementation, the sensors are in direct electronic
communication with the corresponding variable-drive control unit
143. Previously, irrigation systems may have employed
rod-and-switch actuators. These actuators may be replaced with the
sensors 144 configured to monitor (e.g., determine) the
span-to-span alignment of the irrigation system 100. For example,
the sensors 144 are configured to determine an angle between the
corresponding spans. In one or more implementations, the sensors
144 may be potentiometers, captive alignment sensors, laser based
alignment sensors, non-contact proximity sensors, or other devices
capable of quantifiably measuring the span alignment (e.g.,
determining an angle value between the corresponding spans) rather
than merely determining if the respective span 106, 108, 109 is out
of alignment beyond a preset maximum value. As described above, the
sensors 144 (potentiometers, the captive alignment sensors, the
laser based alignment sensors, and/or the non-contact proximity
sensors) are in electronic communication with the variable-drive
control unit 143. In response, the variable-drive control unit 143
is configured to furnish (e.g., provide, generate, transmit) one or
more drive unit signals to control the switched reluctance motor
142. For example, the processor 202 of the variable-drive control
unit 143 is configured to translate the angle information furnished
by the sensor 144 into speed information that is utilized to
control the switched reluctance motor 142 (e.g., control the speed
of the corresponding span 106, 108, 109). Thus, the variable-drive
control unit 143 may furnish one or more drive unit signals that
are configured to cause a specified drive unit 118 to modify the
speed (e.g., increase the speed, decrease the speed) of the unit
118 (e.g., switched reluctance motor 142), which causes the
corresponding span 106, 108, 109 to vary in speed. In an
implementation, the control device 130 may be configured to
communicate with each variable-drive control unit during operation
of the irrigation system 100. For example, the variable-drive
control unit 143 may be configured to furnish diagnostic and/or
performance information regarding the variable-drive unit 118 to
the control device 130.
[0023] In an implementation, a sensor 144 is configured to
continually monitor (determine) the alignment values (e.g., angles)
of the corresponding spans 106, 108, 109. In turn, the
variable-drive control unit 143 is configured to furnish a drive
unit signal configured to cause the corresponding drive unit 118 to
continuously modify the speed of the drive unit 118 (e.g., modify
the speed of the switched reluctance motor 142) to re-align the
corresponding mis-aligned span 106, 108, 109. Thus, the
variable-drive control unit 143 is configured to continuously
provide signals, based upon the sensor 144 signal, to cause at
least substantially near-perfect (e.g., near-horizontal alignment)
between the corresponding spans by way of the switched-reluctance
motors 142. For example, the speed of the drive unit 118 may be
varied (via one or more drive unit signals) based upon a deviation
from a zero degree (0.degree. span to span alignment). In one or
more implementations, the irrigation system 100 (e.g., sensors 144,
variable-drive control unit 143, etc.) may utilize one or more
motor control techniques to adjust the speed of the drive units 118
and/or measure the alignment of a particular span. For example, the
irrigation system 100 may utilize a
proportional-integral-derivative control algorithm, or the like, to
fine tune the speed of a particular drive unit 118. The
variable-drive control unit 143 is configured to continuously
furnish one or more drive unit signals to the drive units 118 when
the sensor 144 determines that a particular span is
mis-aligned.
[0024] Thus, in operation, drive unit (control) signals configured
to adjust the set speed of a particular drive unit 118 are
furnished to the particular drive unit 118, which causes a drive
unit speed adjustment. As described above, the drive unit signals
may be based on potentiometer signals, captive alignment sensor
signals, laser based alignment sensor signals, non-contact
proximity sensor signals, and/or other parameters useful in
determining a new set speed for a particular drive unit. As
described above, the variable-drive control unit 143 includes a
processor 202 that is configured to receive and to utilize data
(information) from the tower structures 110, 111, 112 in
determining the set speed for a particular drive unit 118. In an
implementation, the processor 202 may comprise a microcontroller
that includes dedicated logic (e.g., circuitry) for controlling the
variable-drive units 118 and/or the switched reluctance motors 142.
For example, the variable-drive control unit 143 may be in
communication with each of the tower structures 110, 111, 112 by
way of sensors 144, or the like. As described above, this may allow
for finer speed control and dynamic alignment correction of the
irrigation system 100.
CONCLUSION
[0025] Although the subject matter has been described in language
specific to structural features and/or process operations, it is to
be understood that the subject matter defined in the appended
claims is not necessarily limited to the specific features or acts
described above. Rather, the specific features and acts described
above are disclosed as example forms of implementing the
claims.
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