Patent ID: 12235103

In accordance with common practice, the various features illustrated in the drawings may not be drawn to scale. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may be simplified for clarity. Thus, the drawings may not depict all of the components of a given apparatus (e.g., device) or method. Finally, like reference numerals may be used to denote like features throughout the specification and figures.

DETAILED DESCRIPTION

Circuitry for identifying a misaligned wheeled irrigation tower within a plurality of wheeled irrigation towers is described. The circuitry may include a test resistance configured for installation in a center pivot irrigation system. The circuitry may also include a plurality of resistances. Each of the plurality of resistances may be configured for installation in a wheeled irrigation tower of the center pivot irrigation system and to be coupled in series with the test resistance. Each of the plurality of resistances may be configured to be coupled to a corresponding switch of a respective wheeled irrigation tower and a neutral line. The circuitry may further include detection circuitry coupled to the test resistance. The detection circuitry may be configured, when installed in the center pivot irrigation system, to identify a misaligned wheeled irrigation tower of a plurality of wheeled irrigation towers based on a voltage corresponding to the test resistance. The detection circuitry may be configured to identify the misaligned wheeled irrigation tower based on an increase in the voltage corresponding to the test resistance relative to a first voltage corresponding to the test resistance when the plurality of wheeled irrigation towers are aligned.

Each resistance of the plurality of resistances may be configured to be coupled in parallel with each other resistance of the plurality of resistances. Each resistance of the plurality of resistances may be configured to be separated from the test resistance when the corresponding switch is opened as a result of a misalignment between the misaligned wheeled irrigation tower and a neighboring wheeled irrigation tower.

The detection circuitry may include an analog-to-digital converter configured to convert the voltage to a digital voltage signal. The detection circuitry may also include indicator circuitry that may be configured to identify the misaligned wheeled irrigation tower based on the digital voltage signal, and that may be configured to indicate the misaligned wheeled irrigation tower. The indicator circuitry may be a processor configured to compare the digital voltage signal to at least one threshold voltage. The indicator circuitry may be configured to identify the misaligned wheeled irrigation tower based on a look-up table.

The detection circuitry may be configured to compare the digital voltage signal to one or more calibration voltages. The detection circuitry may include an analog detection circuit configured to identify which of the plurality of wheeled irrigation towers is the misaligned wheeled irrigation tower.

The circuitry may include communication circuitry coupled to the detection circuitry. The communication circuitry may be configured to send an identification indication of the misaligned wheeled irrigation tower in response to the detection circuitry identifying the misaligned wheeled irrigation tower.

The circuitry may include communication circuitry configured to receive a plurality of wheeled irrigation tower deactivation indications. The detection circuitry may be configured to measure at least one calibration voltage. The detection circuitry may be configured to determine a plurality of threshold voltages based on the at least one calibration voltage.

A retrofit kit to enable identification of a misaligned wheeled irrigation tower within a plurality of wheeled irrigation towers is also described. The retrofit kit may include a test resistance configured to be coupled to a safety circuit of a center pivot irrigation system. The retrofit kit may also include a plurality of resistances. Each resistance of the plurality of resistances may be configured to be coupled to the safety circuit between a switch and a neutral line of a wheeled irrigation tower. The retrofit kit may further include detection circuitry configured to be coupled to the test resistance. The detection circuitry may be configured to identify a misaligned wheeled irrigation tower of a plurality of wheeled irrigation towers based on a voltage corresponding to the test resistance. The voltage may be based on which of the plurality of resistances is connected to the test resistance via the safety circuit. The detection circuitry may be configured to identify the misaligned wheeled irrigation tower based on an increase in the voltage corresponding to the test resistance relative to a first voltage corresponding to the test resistance when the plurality of wheeled irrigation towers are aligned.

Each resistance of the plurality of resistances may be configured to be coupled in parallel with each other resistance of the plurality of resistances. The detection circuitry may include an analog-to-digital converter configured to convert the voltage to a digital voltage signal. The detection circuitry may include indicator circuitry configured to identify the misaligned wheeled irrigation tower based on the digital voltage signal, and may be configured to indicate the misaligned wheeled irrigation tower.

The retrofit kit may include communication circuitry coupled to the detection circuitry. The communication circuitry may be configured to send an identification indication of the misaligned wheeled irrigation tower in response to the detection circuitry identifying the misaligned wheeled irrigation tower.

The retrofit kit may include instructions for installing the test resistance, the plurality of resistances, and the detection circuitry in the center pivot irrigation system. The retrofit kit may include a printed web address to instructions for installing the test resistance, the plurality of resistances, and the detection circuitry in the center pivot irrigation system.

A method for installing a retrofit kit in a center pivot irrigation system to enable identification of a misaligned wheeled irrigation tower is also described. The method may include attaching a test resistance and detection circuitry to a safety circuit of a center pivot irrigation system. The detection circuitry may be configured to identify a misaligned wheeled irrigation tower of a plurality of wheeled irrigation towers based on a voltage corresponding to the test resistance. The method may also include attaching each of a plurality of resistances between a switch and a neutral line of the safety circuit at a respective wheeled irrigation tower of the plurality of wheeled irrigation towers.

The method may include a calibration procedure. The calibration procedure may include deactivating each wheeled irrigation tower of the plurality of wheeled irrigation towers and sending a deactivation indication to the detection circuitry for each wheeled irrigation tower deactivation.

Various embodiments are now described with reference to the figures, in which like reference numbers may indicate functionally similar elements. The systems and methods as generally described and illustrated in the figures herein could be arranged and designed in a wide variety of different embodiments. Thus, the following more detailed description of several embodiments, as represented in the Figures, is not intended to limit scope, as claimed, but is merely representative of the systems and methods.

As used herein, the term “plurality” may indicate two or more. For example, a plurality of components may refer to two or more components. As used here, the term “couple” and variations thereof may denote a direct or indirect connection. For example, if a first component is coupled to a second component, then the first component may be directly connected to the second component (with one or more wires, for example) or may be indirectly connected to the second component through one or more other components. Further, it is to be appreciated that certain ordinal terms (e.g., “first” or “second”) can be provided for identification and ease of reference and may not necessarily imply physical characteristics or ordering. Therefore, as used herein, an ordinal term (e.g., “first,” “second,” “third”) used to modify an element, such as a structure, a component, an operation, etc., does not necessarily indicate priority or order of the element with respect to another element, but rather distinguishes the element from another element having a same name (but for use of the ordinal term). In addition, as used herein, indefinite articles (“a” and “an”) can indicate “one or more” rather than “one.” As used herein, a structure or operation that “comprises” or “includes” an element can include one or more other elements not explicitly recited. Thus, the terms “including,” “comprising,” “having,” and variations thereof signify “including but not limited to” unless expressly specified otherwise. Further, an operation performed “based on” a condition or event can also be performed based on one or more other conditions or events not explicitly recited. As used in this application, the terms “an embodiment,” “one embodiment,” “another embodiment,” or analogous language do not refer to a single variation of the disclosed subject matter; instead, this language refers to variations of the disclosed subject matter that can be applied and used with a number of different implementations of the disclosed subject matter. An enumerated listing of items does not imply that any or all of the items are mutually exclusive and/or mutually inclusive, unless expressly specified otherwise.

FIG.1is a diagram illustrating one example of a center pivot irrigation system100. The center pivot irrigation system100may include a pivot center102and a plurality of wheeled irrigation towers106. In the example shown inFIG.1, the center pivot irrigation system100includes five wheeled irrigation towers106. It should be noted that a different number of wheeled irrigation towers106may be utilized in various embodiments. Irrigation pipe may be mounted between the pivot center102and a wheeled irrigation tower106, and between wheeled irrigation towers106. The irrigation pipe may be supported by trusses. A structure between wheeled irrigation towers (including the irrigation pipe and the trusses, for example) may be referred to as a span. The wheels on each wheeled irrigation tower106allow the center pivot irrigation system100to rotate around the pivot center102. The wheels may be driven by, for example, electrical motors and/or hydraulics. Sprinkler nozzles may be coupled to the irrigation pipe in order to deliver pressurized fluid (e.g., water, fertilizer, and/or pesticide). A combination of the wheeled irrigation towers106, intervening sprinkler pipes, and/or optional trusses may be referred to as a pivot104. In addition, it should be noted that intervening sprinkler pipes and optional trusses may be referred to as spans.

In various embodiments, the pivot104may rotate around the pivot center102. For example, each wheeled irrigation tower106may move when that wheeled irrigation tower106comes out of line with one or more other wheeled irrigation towers106. For instance, a wheeled irrigation tower106may trigger movement when the wheeled irrigation tower106comes out of line from another wheeled irrigation tower106. Wheeled irrigation towers106that are farther away from the pivot center102move more often or faster on average than wheeled irrigation towers106that are closer to the pivot center102.

In some cases, a wheeled irrigation tower106may become misaligned. As used herein, the terms “misalign,” “misaligned,” and other variations may refer to a wheeled irrigation tower that is out of line beyond a particular or specified amount or degree. For example, a wheeled irrigation tower may advance too far (e.g., beyond a particular or specified amount) ahead of one or more other wheeled irrigation towers. In another example, a wheeled irrigation tower may fall too far (e.g., beyond a particular or specified amount or degree) behind one or more other wheeled irrigation towers. As a consequence, the wheeled irrigation towers106may become misaligned. As illustrated inFIG.1, the misaligned wheeled irrigation tower108is one of the wheeled irrigation towers106where a bend or change in direction beyond a particular or specified degree or amount has occurred. For example, the misaligned wheeled irrigation tower108may comprise a point or region at which the pivot104changes direction beyond a specified or particular amount or degree. In order to prevent additional problems (e.g., the pivot center102falling over, damage to the center pivot irrigation system100, irrigation failure, etc.), the center pivot irrigation system100may include a safety circuit.

The safety circuit may include a switch (e.g., limit switch, micro switch) at each wheeled irrigation tower106. The safety circuit runs through the switches, which may be closed (e.g., conducting) under normal operation. A voltage (for driving the motorized wheels) may be sourced from the pivot center102. A safety line may run along the entire length of the pivot104and may return on a safety circuit. If the pivot104becomes misaligned beyond a particular or specified amount, a switch (e.g., limit switch, micro switch) opens at one of the wheeled irrigation towers106. For example, the switch at the misaligned wheeled irrigation tower108may open. The safety circuit may be read at the pivot center102. In various embodiments, the safety circuit may have a specified voltage applied. If the safety circuit does not have a specified voltage (e.g.,120alternating current volts (VAC)), the pivot104may stop moving. In other various embodiments, the safety circuit may serve as a neutral line. If a switch on the safety circuit opens, the safety circuit (e.g., neutral line) may be disconnected and the pivot104may stop moving. This stoppage may prevent the pivot104from falling over. As described above, wheeled irrigation towers106may be triggered to move or adjust when they become out of line (by less than the particular or specified amount). When a wheeled irrigation tower106becomes misaligned (beyond the particular or specified amount), the safety circuit may be broken, causing the pivot104to stop. The term “misaligned” and variations thereof may refer to cases when a wheeled irrigation tower106becomes out of line beyond a particular or specified amount or degree and/or when a bend or angle of the pivot104at the wheeled irrigation tower106is beyond a particular or specified amount or degree. For example, a wheeled irrigation tower106may be considered misaligned when the wheeled irrigation tower106is far enough out of line to break the safety circuit (e.g., open a limit switch or micro switch in the safety circuit). Additionally or alternatively, a wheeled irrigation tower106may be considered misaligned in a case where a corresponding switch in the safety circuit has caused the pivot104to stop moving indefinitely.

It may be difficult to determine which of the wheeled irrigation towers106is misaligned. For example, some crops (e.g., corn) may grow to be tall, which may obstruct a view of the wheeled irrigation towers106, making it difficult to ascertain the misaligned wheeled irrigation tower108. The image ofFIG.6provides one example of how crops may obstruct a view of the wheeled irrigation towers106. In addition, the pivot104may be relatively long (e.g., one quarter of a mile long), which may make it difficult to ascertain the misaligned wheeled irrigation tower108. Furthermore, it may be time-consuming and/or expensive to get an elevated observation of the pivot104to ascertain the misaligned wheeled irrigation tower108. Due to the length of the pivot104and/or the point of view of an observer, it may be difficult to identify specifically which wheeled irrigation tower106is misaligned. Additionally or alternatively, resources may be wasted in an effort to determine and/or access the misaligned wheeled irrigation tower108to address the misalignment. Operational downtime may affect crop watering. In order to address these problems, the systems and methods disclosed herein may provide approaches to detect (e.g., identify, indicate, and/or communicate) information related to a misaligned wheeled irrigation tower108.

In various embodiments, detection circuitry may be installed in and/or implemented in the center pivot irrigation system100. As used herein, the term “installed in” and variations thereof may mean to be installed to, installed in, installed on, and/or installed within (e.g., inside of). For example, the detection circuitry may be installed in the pivot center102, the pivot104and/or a wheeled irrigation tower106. The detection circuitry may identify, indicate, and/or communicate information regarding a misaligned wheeled irrigation tower108. In order to indicate which wheeled irrigation tower106is the misaligned wheeled irrigation tower108, a voltage (e.g., direct current (DC) voltage (VDC), or alternating current (AC) voltage (VAC)) may be applied to the safety circuit with a test resistance. In various embodiments, the test resistance may be coupled in series with a voltage source. In various embodiments, a filter may be utilized to remove or convert AC voltage in order to isolate DC voltage. For example, a low DC voltage (e.g., 3.3 VDC or other voltage) may be applied to the safety circuit with a high ohm resistor in series with the voltage source. At each wheeled irrigation tower106, a resistance (e.g., a resistor) may be coupled between the safety circuit and the neutral line. This arrangement may create a voltage divider circuit.

When a wheeled irrigation tower106is misaligned, the corresponding switch (e.g., limit switch, micro switch) may open, thereby removing any resistance(s) after the switch. In various embodiments, opening the switch may remove the resistance (e.g., resistor) from that wheeled irrigation tower106and/or resistance(s) for any wheeled irrigation tower(s)106beyond the misaligned wheeled irrigation tower108from the voltage divider circuit. Removing the resistance(s) may increase a measurable voltage. For example, this may increase a voltage that can be read by an Analog to Digital Converter (ADC) on the pivot104and/or pivot center102. The voltage may differ depending on which wheeled irrigation tower106is misaligned. Accordingly, the detection circuitry may be implemented in order to identify a misaligned wheeled irrigation tower108based on the voltage. For example, the detection circuitry may measure the voltage. Different voltage levels may correspond to different misaligned wheeled irrigation towers108. In various embodiments, the detection circuitry may convert the measured voltage to a digital voltage signal using an ADC. The detection circuitry may utilize the digital voltage signal to determine the misaligned wheeled irrigation tower108. For example, the detection circuitry may include digital logic that utilizes a function and/or look-up table to map the digital voltage signal to an indicator of the misaligned wheeled irrigation tower108. In various embodiments, the detection circuitry may utilize analog signal processing to generate an indicator of the misaligned wheeled irrigation tower108(without converting the voltage to a digital signal, for example). Accordingly, the detection circuitry may include digital and/or analog detection circuitry for identifying and/or communicating information regarding the misaligned wheeled irrigation tower108.

In various embodiments, the detection circuitry may communicate data indicating which of the wheeled irrigation towers106is the misaligned wheeled irrigation tower108to a remote device. For example, the detection circuitry may send a signal to another device indicating the misaligned wheeled irrigation tower108. The signal may be communicated using a wired and/or wireless link. For example, the signal may be communicated using a mesh network, Wi-Fi network, cellular network, Ethernet network, and/or one or more other wired and/or wireless networks. In various embodiments, the data may be communicated to a server, computer, smartphone, tablet device, vehicle, and/or other device. One or more devices may notify one or more users which of the wheeled irrigation towers106is misaligned. For example, one or more devices may present a message (e.g., misaligned wheeled irrigation tower number, map of the misaligned wheeled irrigation tower108, diagram on the misaligned wheeled irrigation tower108, etc.) on a display. In various embodiments, a console on the center pivot or pivot may provide information identifying the misaligned wheeled irrigation tower108. The console may comprise, for example, a display screen and/or a set of lights to identify the misalignment. In certain embodiments, there may be one light, such as an LED light, that corresponds to each wheeled irrigation tower106with the lights arranged (e.g., arranged in a linear fashion) to correspond to the arrangement of the pivot104.

As described herein, the detection circuitry may identify and/or communicate a misaligned wheeled irrigation tower108. Examples of detection circuitry may include electronic circuits, integrated circuits, circuits with discrete components (e.g., resistors, capacitors, transistors, metal-oxide-semiconductor field-effect transistors (MOSFETs)), application-specific integrated circuits (ASICs), computers, and/or devices that include one or more processors, memory cells, latches, logic gates, etc. For instance, the detection circuitry may include discrete components and/or a processor (e.g., microprocessor) that may be used to detect (e.g., identify, indicate, and/or communicate) information regarding a misaligned wheeled irrigation tower108. In various embodiments, the processor may include and/or access software in memory and/or firmware. For example, the detection circuitry may include memory. The memory may be included on-board the processor or may be separate from the processor. The memory may store instructions and/or data (e.g., voltage samples and/or current samples, etc.). Additionally or alternatively, the memory or a separate memory may store firmware. In various embodiments, the detection circuitry may be housed within a box mounted on a structure at or near the pivot center102.

FIG.2is a flow diagram illustrating one embodiment of a method200for detecting a misaligned wheeled irrigation tower. In various embodiments, the method200may be performed by the center pivot irrigation system100and/or the detection circuitry described in connection withFIG.1. In various embodiments, the method200may be performed by another center pivot irrigation system and/or detection circuitry. For example, the method200may be performed in a center pivot irrigation system with a different number of wheeled irrigation towers. A voltage (e.g., DC or AC voltage) may be applied202to safety circuitry of wheeled irrigation towers. For example, the voltage may be applied202by a center pivot irrigation system and/or detection circuitry. In various embodiments, the voltage may be applied202to a return line of the safety circuitry. In various embodiments, a DC or an AC voltage source may be utilized. In various embodiments, the voltage may be applied202in response to detecting that the safety circuit is open. For example, when a switch on a return line of the safety circuit is open, the center pivot irrigation system and/or the detection circuitry may apply202the voltage to the safety circuitry for measurement. In various embodiments, when a switch on the return line of the safety circuit is open, the center pivot irrigation system may control a relay (at the pivot center, for example) to stop driving a voltage on a forward circuit line or a reverse circuit line, which may halt pivot movement.

A voltage corresponding to a test resistance (e.g., one or more resistors) may be measured204. For example, the center pivot irrigation system and/or detection circuitry may measure204the test resistance. The voltage corresponding to the test resistance may be measured across the test resistance (e.g., from a terminal of the test resistance to neutral or between terminals of the test resistance). In various embodiments, measuring204the test resistance may include converting an analog voltage corresponding to the test resistance to a digital voltage and/or sampling the digital voltage. In various embodiments, the test resistance may be coupled in series with the voltage source. In various embodiments, the voltage source may be a voltage supply for the detection circuitry.

A misaligned wheeled irrigation tower of the wheeled irrigation towers may be determined206based on the voltage. This may be accomplished as described in relation toFIG.1. For example, the detection circuitry and/or the center pivot irrigation system may determine a wheeled irrigation tower corresponding to the voltage based on the voltage level (e.g., amplitude). For instance, as more resistances corresponding to the wheeled irrigation towers are excluded from the voltage divider circuit due to an open switch, the voltage level increases. The voltage level may depend on the resistances (e.g., resistors) implemented at each wheeled irrigation tower and/or the supplied voltage. In various embodiments, determining206the misaligned wheeled irrigation tower may be based on a mapping between predetermined voltage levels (e.g., voltage ranges) and the wheeled irrigation towers. For example, the detection circuitry may look up the misaligned wheeled irrigation tower in a look-up table based on the voltage and/or may compare the voltage to one or more thresholds and/or calibration voltages. It should be noted that the detection circuitry may be implemented for different numbers of wheeled irrigation towers (e.g., two or more).

The misaligned wheeled irrigation tower may be indicated208. For example, the detection circuitry and/or the center pivot irrigation system may indicate208the misaligned wheeled irrigation tower (e.g., may provide information regarding the misaligned wheeled irrigation tower). This may be accomplished as described in connection withFIG.1. For example, detection circuitry may present an indicator on a display and/or may transmit data indicating the misaligned wheeled irrigation tower. In some cases, the indicator may be used to fix the misalignment. In various embodiments, the misalignment may be fixed manually (e.g., a technician may go to the identified misaligned tower to fix the misalignment). Accordingly, the indicator may enable efficient detection and repair of the misalignment, as a technician may be able to go directly to the misaligned tower instead of searching for and/or determining which of the towers is misaligned.

FIG.3is a circuit diagram illustrating an example of circuitry for identifying a misaligned wheeled irrigation tower within a plurality of wheeled irrigation towers. The circuitry may include a test resistance312. The test resistance312may be configured for installation in a center pivot irrigation system. For example, the test resistance312may include one or more terminals (or may be included in circuitry that includes one or more terminals) for installation in a center pivot irrigation system. The test resistance312may be implemented with one or more resistors, one or more impedances, one or more transistors, and/or one or more diodes, for example. In various embodiments, the test resistance312may be coupled to a voltage source310. For example, the circuitry may include or may be coupled to a voltage source310. Examples of the voltage source310include a voltage supply, or a coupling or connection to a voltage supply. In various embodiments, the voltage source310may be coupled in series with the test resistance312(e.g., RT). In some examples, the voltage source310may be an AC or a DC voltage source. In various embodiments, the voltage source310may be a DC voltage source that is coupled in series with an AC voltage source.

The circuitry may include a plurality of resistances314a-e(e.g., resistors). Although five resistances314a-eare illustrated inFIG.3, a different number of resistances may be utilized in various embodiments. Each of the plurality of resistances314a-emay be configured for installation in a wheeled irrigation tower318a-eof the center pivot irrigation system. In various embodiments, each of the plurality of resistances314a-emay be configured to be coupled in series with the test resistance312(when a corresponding switch316a-eis closed, for example). In various embodiments, each resistance of the plurality of resistances314a-emay be configured to be coupled in parallel with each other resistance of the plurality of resistances314a-e. Each of the plurality of resistances314a-emay be configured to be coupled to a corresponding switch316a-eof a respective wheeled irrigation tower318a-eand to a neutral line322. For example, each of the resistances314a-emay be coupled to a terminal or to a wire from a terminal of a corresponding switch316a-e. In various embodiments, each resistance of the plurality of resistances314a-eis configured to be separated from the test resistance312when the corresponding switch316a-eis opened as a result of a misalignment between the misaligned wheeled irrigation tower and a neighboring wheeled irrigation tower. In various embodiments, each of the switches316a-emay be part of or may be coupled to a safety circuit line324(e.g., a safety circuit return line). In various embodiments, each of the resistances314a-emay be coupled to safety circuit line324and/or may be coupled between the safety circuit line324and neutral line322.

As illustrated inFIG.3, each wheeled irrigation tower318a-emay have a corresponding switch316a-e(e.g., limit switch, micro switch), with a resistance314a-ecoupled between the switch316a-eand a neutral line322. In various embodiments, the circuitry illustrated inFIG.3may comprise a voltage divider circuit.

An example of a voltage divider circuit may be expressed in accordance with Equation (1)

Vo⁢u⁢t=R2R1+R2·Vin(1)

In Equation (1), Vinmay be an input voltage (e.g., a low input voltage sourced from a control box such as 3.3 VDC or another voltage), R1may be an example of a test resistance (RT), and R2may be a parallel resistance value of the resistances314a-ealong the pivot (e.g., an equivalent resistance of the plurality of resistances314a-eat the wheeled irrigation towers318a-e). For instance, two resistors in parallel may be combined in accordance with Equation (2).

Rt⁢o⁢t⁢a⁢l=Ra⁢RbRa+Rb(2)

For example, Rtotalmay be an example of R2from Equation (1), where Raand Rbare examples of two parallel resistances314a-bat two wheeled irrigation towers318a-b. Equation (2) may be simplified to Equation (3) if the same value of resistance314a-eis used along the entire length of the pivot (e.g., at each wheeled irrigation tower).

Rt⁢o⁢t⁢a⁢l=RN(3)

In Equation (3), R is the resistance value at each wheeled irrigation tower318a-eand N is the number of resistances314a-e. It should be noted that different resistance values may be used at different wheeled irrigation towers318a-ein various embodiments, especially if the pivot is long (e.g., 10 or more wheeled irrigation towers).

In some approaches, the circuit illustrated inFIG.3may be expressed in accordance with Equation (4).

V=I⁡(RT+1/∑n=1N1Rn)(4)

In Equation (1), V is the voltage (e.g., voltage level or amplitude) of the voltage source310, I is current, RT is the test resistance312, Rnis the n-th resistance (corresponding to the n-th wheeled irrigation tower318a-e), and N is a number of wheeled irrigation towers with closed switches (if any) up to the first open switch from the voltage source310. As can be observed, the voltage over the test resistance312(e.g., VRT) may change (e.g., increase) as an open switch excludes more wheeled irrigation towers (e.g., as N decreases). Accordingly, a predetermined voltage level may correspond to each potentially misaligned wheeled irrigation tower318a-e. It should be noted that various values for the voltage of the voltage source310, the test resistance312, and/or resistances314a-emay be utilized. In various embodiments, the test resistance312and each resistance314a-emay be 20 kiloohms (kΩ) and the voltage of the voltage source310may be a low voltage.

In various embodiments, the circuitry may include detection circuitry320. The detection circuitry320may be coupled to the test resistance312. The detection circuitry320may be configured (when installed in the center pivot irrigation system, for example) to identify a misaligned wheeled irrigation tower of a plurality of wheeled irrigation towers based on a voltage corresponding to the test resistance312. For example, the detection circuitry320may be configured to identify the misaligned wheeled irrigation tower based on an increase in the voltage corresponding to the test resistance312relative to a voltage corresponding to the test resistance312when the plurality of wheeled irrigation towers is aligned.

FIG.4is a circuit diagram illustrating another example of circuitry for identifying a misaligned wheeled irrigation tower within a plurality of wheeled irrigation towers. The components inFIG.4may be similar to the components described in connection withFIG.3. For example, one or more of the components illustrated inFIG.4(a voltage source410, a test resistance412, a safety circuit line424, wheeled irrigation towers418a-e, switches416a-e, resistances414a-e, and/or a neutral line422) may be configured as described with corresponding components in connection withFIG.3.

In various embodiments, the detection circuitry420may include an analog-to-digital converter428(ADC) and/or indicator circuitry426. The ADC428may be coupled to the test resistance412. For example, the ADC428may be coupled to two terminals of the test resistance412or may be coupled to one terminal of the test resistance412and neutral line422. The ADC428may be configured to convert the voltage corresponding to the test resistance412to a digital voltage signal. For example, the ADC428may convert an analog voltage over the test resistance412to a digital voltage signal. The digital voltage signal may be provided to the indicator circuitry426.

The indicator circuitry426may be coupled to the ADC428. Examples of the indicator circuitry426include a processor, ASIC, digital logic circuitry, integrated circuitry, etc. The indicator circuitry426may be configured to identify the misaligned wheeled irrigation tower based on the digital voltage signal. For example, the indicator circuitry426may determine, based on the digital voltage signal (e.g., the voltage level or amplitude of the digital voltage signal), which of the wheeled irrigation towers is a misaligned wheeled irrigation tower. For example, the indicator circuitry426may identify the misaligned wheeled irrigation tower based on the digital voltage signal and/or may communicate an indicator to another device as described in connection withFIG.1.

The indicator circuitry426may utilize one or more techniques to identify the misaligned wheeled irrigation tower. In various embodiments, the indicator circuitry426may be configured to compare the digital voltage signal to at least one threshold voltage. For example, the indicator circuitry426may determine the misaligned wheeled irrigation tower based on whether the digital voltage signal satisfies a threshold voltage. In various embodiments, the indicator circuitry426may compare the digital voltage signal to a plurality of threshold voltages, where each threshold voltage of the plurality of threshold voltages respectively corresponds to each wheeled irrigation tower of the plurality of wheeled irrigation towers. In various embodiments, the indicator circuitry426may be configured to determine a subset of the plurality of threshold voltages that is satisfied and to indicate the misaligned wheeled irrigation tower corresponding to the subset of the plurality of threshold voltages that is satisfied. For example, the indicator circuitry426may compare the digital voltage signal to a set of threshold voltages (e.g., increasing threshold voltages) over a range. The subset (or all) of the set of threshold voltages that is or are satisfied may correspond to a particular misaligned wheeled irrigation tower. In various embodiments, the indicator circuitry426may identify the misaligned wheeled irrigation tower based on a look-up table. For example, the indicator circuitry426may look up the misaligned wheeled irrigation tower corresponding to a value of the digital voltage signal in the look-up table. In various embodiments, the values of the threshold(s) and/or of the look-up table may be determined during a calibration procedure. In various embodiments, the indicator circuitry426may be configured to compare the voltage (e.g., digital voltage signal) to one or more voltages (e.g., calibration voltages) corresponding to one or more wheeled irrigation towers to identify the misaligned wheeled irrigation tower. For example, the indicator circuitry426may determine which of the calibration voltages is nearest to the voltage (e.g., digital voltage signal). For instance, the indicator circuitry426may determine a difference (e.g., distance, subtraction) between the digital voltage signal and each of a set of calibration voltages. The smallest difference between the digital voltage signal and one of the calibration voltages may indicate the misaligned wheeled irrigation tower.

The indicator circuitry426may be configured to indicate the misaligned wheeled irrigation tower (e.g., to indicate which of the wheeled irrigation towers is a misaligned irrigation tower). For example, the detection circuitry420may include and/or may be coupled to communication circuitry (e.g., a communication interface). The indicator circuitry426may provide an identification indication of the wheeled irrigation tower to the communication circuitry. The communication circuitry may be configured to send the identification indication of the misaligned wheeled irrigation tower in response to the detection circuitry420identifying the misaligned wheeled irrigation tower. For example, the indicator circuitry426may use the communication circuitry to send the identification indication to another device (e.g., to a display, to a smartphone, tablet, computer, laptop, and/or server). Examples of the identification indication may include a number, text, characters, and/or an image, etc. In various embodiments, the communication circuitry may implement one or more communication protocols (e.g., Wi-Fi, long-range Wi-Fi, Zigbee, Long-Term Evolution (LTE), 3G, CDMA, Bluetooth, Ethernet, and/or Universal Serial Bus (USB)).

In various embodiments, the communication circuitry may be configured to receive information during a calibration procedure. For example, the communication circuitry may be configured to receive a plurality of wheeled irrigation tower deactivation indications. The communication circuitry may provide the wheeled irrigation tower deactivation indications to the detection circuitry420. The detection circuitry may be configured to measure at least one calibration voltage in response to at least one of the plurality of wheeled irrigation tower deactivation indications. For example, when a wheeled irrigation tower deactivation indication is received, the detection circuitry420may measure and/or store a calibration voltage corresponding to the test resistance412. In various embodiments, the detection circuitry420may measure a calibration voltage when all of the switches416a-eare closed (e.g., when all of the wheeled irrigation towers are aligned). As described herein, the calibration voltages may be utilized to identify the misaligned wheeled irrigation tower in various embodiments. For example, a voltage (e.g., the digital voltage signal) may be compared to the calibration voltages. The calibration voltage that is nearest to the digital voltage signal may correspond to the misaligned wheeled irrigation tower. For example, assuming calibration voltages of 100 millivolts (mV), 200 mV, and 300 mV, a digital voltage signal of 150 mV would correspond to (e.g., be nearest to) the 200 mV calibration voltage and a digital voltage signal of 149 mV would correspond to (e.g., be nearest to) the 100 mV calibration voltage. In additional examples, a digital voltage signal of 249 mV would correspond to the 200 mV calibration voltage and a digital voltage signal of 250 mV would correspond to the 300 mV calibration voltage. For instance, neighboring calibration voltages may be used to determine boundaries as halfway between the neighboring calibration voltages. Accordingly, the calibration value that is nearest to the digital voltage signal (within a boundary) may indicate the misaligned wheeled irrigation tower.

In various embodiments, the detection circuitry420may be configured to determine a plurality of threshold voltages and/or values of a look-up table based on the at least one calibration voltage. For example, the detection circuitry420may determine a set of threshold voltages and/or look-up table values as voltage values between the calibration voltages. For instance, if calibration voltages are 100 millivolts (mV), 200 mV, and 300 mV, the detection circuitry420may set thresholds at 150 mV and 250 mV.

In various embodiments, the detection circuitry420may include an analog detection circuit configured to identify which of the plurality of wheeled irrigation towers is the misaligned wheeled irrigation tower. For example, the detection circuitry420may include one or more operational amplifiers or buffers. For example, a set of operational amplifiers may be tuned with threshold voltages corresponding to the wheeled irrigation towers (e.g., threshold voltages with approximately at 100 to 150 millivolt (mV) difference for each wheeled irrigation tower). For instance, the set of operational amplifiers may drive circuitry that indicates the misaligned wheeled irrigation tower. In an example, the operational amplifiers may drive an array of light emitting diodes (LEDs) to activate, deactivate, and/or change colors to indicate which of the wheeled irrigation towers is the misaligned wheeled irrigation tower.

FIG.5illustrates various components that may be utilized in an electronic device502. The electronic device502described in connection withFIG.5may be configured in accordance with one or more of the circuitries described herein and/or may communicate with one or more of the circuitries described herein. For example, the electronic device502may be configured to perform one or more of the methods200described herein. The electronic device502may include a memory501, a communication interface509, an input device511, a processor503, an output device513, a display515, and/or a display controller517. The memory501may store instructions505aand data507a. The processor503may operate on instructions505band data507b. It should be noted that the display515and/or display controller517may not be included in various embodiments. For example, some embodiments of the electronic device502may not have a display. Additionally or alternatively, some embodiments of the electronic device502may include a button interface (e.g., an input device511). Some embodiments of the electronic device502may be controlled on a remote display device (e.g., a touch panel) with communication through a remote device. In various embodiments, the processor503may be configured to identify a misaligned wheeled irrigation tower based on a voltage as described herein.

FIG.6is an image632of a center pivot irrigation system. In various embodiments, one or more components (e.g., test resistance, resistances, switches, ADCs, detection circuitry, and/or indicator circuitry) may be partially or completely housed in one or more enclosures on one or more structures of the center pivot irrigation system as shown inFIG.6. For example, an enclosure may be mounted on a pivot center of a center pivot irrigation system in the image632. A portion of the pivot is also shown in the image632.

FIG.7is a diagram illustrating an example of a retrofit kit734. A retrofit kit734includes a collection of components configured to be installed in a center pivot irrigation system to enable identification of a misaligned wheeled irrigation tower within a plurality of wheeled irrigation towers.

For example, the retrofit kit734may include a test resistance712configured to be coupled to a safety circuit of a center pivot irrigation system. For example, the test resistance712may include one or more couplers (e.g., threads, clips, wires) to enable installation in the center pivot irrigation system.

The retrofit kit734may include a plurality of resistances714. Each resistance of the plurality of resistances714may be configured to be coupled to the safety circuit between a switch and a neutral line of a wheeled irrigation tower. For example, each of the resistances714may include one or more couplers (e.g., threads, clips, wires) to enable installation in a respective wheeled irrigation tower of the center pivot irrigation system.

The retrofit kit734may include detection circuitry720configured to be coupled to the test resistance712. For example, the detection circuitry720may include one or more couplers (e.g., threads, clips, wires) to enable installation in the center pivot irrigation system. In various embodiments, the test resistance712may be a part of or may be included within the detection circuitry720. The detection circuitry720may be configured to identify a misaligned wheeled irrigation tower of a plurality of wheeled irrigation towers based on a voltage corresponding to the test resistance712. The voltage may be based on which of the plurality of resistances is connected to the test resistance712via the safety circuit.

In various embodiments, the detection circuitry720may be configured to identify the misaligned wheeled irrigation tower based on an increase in the voltage corresponding to the test resistance712relative to a voltage corresponding to the test resistance712when the plurality of wheeled irrigation towers are aligned. In various embodiments, each resistance of the plurality of resistances714is configured to be coupled in parallel with each other resistance of the plurality of resistances714. For example, each of the resistances714may be configured to be coupled between a safety return line and a neutral line of a respective wheeled irrigation tower.

In various embodiments, the detection circuitry720may include an ADC configured to convert the voltage to a digital voltage signal. The detection circuitry720may also include indicator circuitry configured to identify the misaligned wheeled irrigation tower based on the digital voltage signal, and configured to indicate the misaligned wheeled irrigation tower.

In various embodiments, the retrofit kit734may include communication circuitry configured to be coupled to the detection circuitry720and/or included in the detection circuitry720. The communication circuitry may be configured to send an identification indication of the misaligned wheeled irrigation tower in response to the detection circuitry720identifying the misaligned wheeled irrigation tower.

In various embodiments, the retrofit kit734may include instructions736for installing the test resistance712, the plurality of resistances714, and the detection circuitry720in the center pivot irrigation system. Additionally or alternatively, the instructions736may include a printed web address to instructions for installing the test resistance712, the plurality of resistances714, and the detection circuitry720in the center pivot irrigation system.

FIG.8is a flow diagram illustrating an example of a method800for installing a retrofit kit in a center pivot irrigation system to enable identification of a misaligned wheeled irrigation tower. The method800may be performed by a user or technician.

A test resistance712may be attached802and detection circuitry720may be attached802to a safety circuit of a center pivot irrigation system. For example, the test resistance712and the detection circuitry720may be attached to a safety circuit at a pivot center or along the pivot. The detection circuitry720may be configured to identify a misaligned wheeled irrigation tower of a plurality of wheeled irrigation towers based on a voltage corresponding to the test resistance712.

Each of a plurality of resistances714may be attached804between a switch and a neutral line of the safety circuit at a respective wheeled irrigation tower of the plurality of wheeled irrigation towers. For example, each resistance may be coupled to a terminal of a respective switch and/or the safety return line at a wheeled irrigation tower.

In various embodiments, installing the retrofit kit734in the center pivot irrigation system may include a calibration procedure. The calibration procedure may include deactivating806each wheeled irrigation tower of the plurality of wheeled irrigation towers. For example, a switch may be (manually or remotely) actuated to deactivate806a wheeled irrigation tower. Deactivating806the wheeled irrigation tower may disconnect the safety circuit (e.g., safety return line). The calibration procedure may include sending808a deactivation indication to the detection circuitry720for each wheeled irrigation tower deactivation. For example, a user or technician may use a device (e.g., smartphone, tablet, computer) to send808the deactivation indication when each wheeled irrigation tower is deactivated. The detection circuitry720may receive the deactivation indication (via communication circuitry, for example) and may measure and store a calibration voltage corresponding to the test resistance712for each of the wheeled irrigation tower deactivations. The calibration voltages may be utilized to determine a set of thresholds or a look-up table as described herein. It should be noted that one or more of the steps, functions, or operations described herein may be omitted in various embodiments.

FIG.9is a block diagram illustrating an example of wheeled irrigation tower circuitry940. In particular,FIG.9illustrates an example of circuitry that may be included in one or more wheeled irrigation towers (of a center pivot irrigation system, for instance). One or more of the elements or components described in connection withFIG.9may be implemented at one or more (e.g., each) wheeled irrigation tower.

In various embodiments, the tower circuitry940may include a forward circuit line956, a reverse circuit line958, a safety out line942, a safety return line924, and a neutral line922. When active, the forward circuit line956may provide voltage for driving the wheeled irrigation towers forward. When active, the reverse circuit line958may provide voltage for driving the wheeled irrigation towers in reverse. The forward circuit line956may be coupled to a terminal (e.g., normally closed terminal) of a drive switch948. The reverse circuit line958may be coupled to a terminal (e.g., normally open terminal) of the drive switch948.

The drive switch948may be a limit switch or micro switch for driving the wheeled irrigation tower. The drive switch948(e.g., a common terminal950of the drive switch948) may be coupled to a relay946at the tower. The relay946may control whether a motor954at the wheeled irrigation tower is supplied with 3-phase power952to drive the wheels of the wheeled irrigation tower. The drive switch948may be actuated by an alignment bar. The alignment bar may be attached to the pivot center and/or may be attached to the wheeled irrigation tower(s).

When a forward circuit is active, the forward circuit line956may be supplied with a voltage (e.g., 120 VAC) and the reverse circuit may be left open. As the pivot moves in forward, the alignment bar will move to activate the drive switch948. This may allow current to flow from the forward circuit to the relay946coil, which may provide 3-phase power952to the motor954. The wheeled irrigation tower will move forward. The alignment bar will consequently move to eventually press the drive switch948again, stopping the current flow from the forward circuit line956to the relay946coil. An opposite procedure may occur when the wheeled irrigation tower travels in reverse.

In the example ofFIG.9, the safety out line942loops back at the last wheeled irrigation tower to become the safety return line924. The safety switch916at each wheeled irrigation tower may be on the safety return line. As described herein, the safety switch916may be a limit switch or micro switch. The safety switch916may be actuated by the alignment bar. It should be noted that the safety switch916is distinct from the drive switch948. For example, the safety switch916is part of the safety circuit and is connected to a different line than the drive switch948. In various embodiments, the allowed range of motion of the safety switch916is greater than that of the drive switch948. This allows the wheeled irrigation tower to realign as it moves around a field. If the tower fails to move for some reason, the alignment bar may continue to move, causing the safety switch916to open. The safety switch916(e.g., safety return line924) may control a relay at the pivot center (e.g., a 120 VAC coil relay with a 3-phase 480 VAC load or the motor954). For example, when the safety switch916opens, the safety return line924may be disconnected, which may cause the relay at the pivot center to change state, thereby stopping the 3-phase power952from driving the motor954.

As illustrated in the example ofFIG.9, a resistance914may be installed between the safety return line924and the neutral line922. If a safety error occurs, a voltage may be applied to the safety return line924(from the pivot center and/or detection circuit, for example) and a voltage on the safety return line924(e.g., corresponding to a test resistance) may be measured. The voltage may vary based on how many resistances are still in the safety circuit before the open safety switch916. Accordingly, the varying voltage may be utilized to identify the misaligned wheeled irrigation tower as described herein.

FIG.10is a diagram illustrating an example of a drive switch1048and a safety switch1016that may be implemented in various embodiments of the systems and methods described herein. As illustrated in this example, the drive switch1048includes an actuator (e.g., arm) and the safety switch1016includes an actuator (e.g., arm). The drive switch1048and the safety switch1016are actuated by an alignment bar1060. The alignment bar1060may be attached (e.g., anchored) to a pivot center and/or to one or more wheeled irrigation towers.

The drive switch1048may be connected to a forward circuit line1056, a reverse circuit line1058, and may have a common1050terminal. The safety switch1016may be connected to a safety return line1024afrom a previous wheeled irrigation tower (or pivot center) and to a safety return line1024bto a next wheeled irrigation tower (if any). In various embodiments, opening the safety switch1016may stop current from flowing on the safety return line back to the pivot center, which may cause a relay at the pivot center to stop providing power on the forward circuit line1056and/or the reverse circuit line1058. In various embodiments, stopping the current flow on the safety circuit may deactivate a pump, fertigator, and/or chemigator to stop working.

The principles and mechanisms taught in this application may be applied not just to center pivot sprinkling mechanisms, but also to laterals, which comprise a type of sprinkler system that moves in a lateral direction rather than a radial direction.

The term “discrete circuit” refers to an electronic circuit built out of discrete components. Examples of discrete components include resistors, capacitors, inductors, transformers, transistors, etc.

The term “processor” should be interpreted broadly to encompass a general purpose processor, a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a controller, a microcontroller, a state machine, and so forth. Under some circumstances, a “processor” may refer to an application-specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc. The term “processor” may refer to a combination of processing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The term “memory” should be interpreted broadly to encompass any electronic component capable of storing electronic information. The term memory may refer to various types of processor-readable media such as random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable PROM (EEPROM), flash memory, magnetic or optical data storage, registers, etc. Memory is said to be in electronic communication with a processor if the processor can read information from and/or write information to the memory. Memory that is integral to a processor is in electronic communication with the processor.

The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement(s). For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may comprise a single computer-readable statement or many computer-readable statements.

The term “computer-readable medium” refers to any available medium that can be accessed by a computer or processor. A computer-readable medium may be non-transitory and tangible. By way of example, and not limitation, a computer-readable medium may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

Software or instructions may also be transmitted over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of transmission medium.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. The method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is required for proper operation of the method that is being described, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

It is to be understood that the claims are not limited to the precise configuration and components illustrated above. Various modifications, changes, and variations may be made in the arrangement, operation, and details of the systems, methods, and apparatus described herein without departing from the scope of the claims.