System and method for position correction using power line carrier communication

Abstract

A method for aligning a cross-over using real-time kinematic (RTK) data transmitted over a power line carrier system is provided. The method of the invention includes the steps of receiving a first set of GPS position data and a second set of RTK data and comparing the two; calculating RTK error correction data and creating an RTK error correction data signal containing the same; modulating the RTK error correction data signal for transmission over the power line carrier; transmitting the RTK error correction data signal over the power line bus onto the power line to the last drive tower; demodulating the RTK error correction data signal and using it to calculate the position of the last drive tower; calculating a straight centerline between the pivot and the last drive unit; calculating the relative distance between each intermediate drive tower and the calculated centerline; and controlling the speed or average run time of each intermediate drive tower to reduce the distance between the current position of each intermediate drive tower and the calculated centerline.

Description

[0001] This application is a divisional application of the Chinese Invention Patent Application with the application date of August 21, 2019, the application number of 2019800556367 (PCT / US2019 / 047549), and the invention name of “System and method for position correction using power line carrier communication”.

[0002] Related Applications

[0003] This application claims priority to U.S. Provisional Application No. 62 / 723,663, filed August 28, 2018.

[0004] BACKGROUND AND SUMMARY TECHNICAL FIELD

[0005] The present invention generally relates to a system and method for providing correction and position signals to various power elements within an irrigation machine to achieve various goals, including alignment control of an irrigation span, guidance of an irrigation machine (e.g., corner and line types), and providing position information to various remote monitoring and control devices. BACKGROUND

[0006] Modern center pivot and linear irrigation systems typically include interconnected spans (e.g., irrigation spans) supported by one or more tower structures to support conduits (e.g., sections of water pipe). In turn, the conduits are further attached to a sprinkler / nozzle system that sprays water (or other applicator) in a desired pattern. In these modern irrigation systems, a large number of power elements are used to control various aspects of the irrigation. These typically include various sensors, sprayers, drive control systems, electric motors, and transducers.

[0007] In the past, irrigation machines have utilized various methods for data communication between system processors. These methods include dedicated hardwired systems (e.g., RS485, TCP / IP, RS232, etc.) and wireless systems (e.g., cellular, Wi-Fi, VHF / UHF radios, spread spectrum radios, etc.). Both of these solutions are expensive and are prone to communication errors. Hardwired systems require the installation of fairly long cables, while wireless systems often require repeaters to enhance the radio signal over long distances. In addition, wireless systems are less reliable due to distance, weather changes, obstructions, induced RF noise, and long delays, especially in cellular communications. Both systems result in errors in position reporting and system delays due to communication failures. The end result of these errors is poor water application uniformity, application delays, and other problems that reduce the yield and profitability of the grower.

[0008] To overcome the limitations of the prior art, there is a need for a reliable and effective communication and control system to control and align the irrigation spans and drive towers in a mechanized irrigation system. Further, there is a need for a system to provide guidance to the steerable elements of the irrigation machine and provide the machine control system and remote operator with a perception of the machine's position (position information). SUMMARY

[0009] To address the shortcomings in the prior art, the present invention provides a system for providing improved communication and position awareness within an irrigation system having at least one span and a drive system for moving the span.

[0010] According to a first preferred embodiment, the present invention comprises a method for transmitting global positioning system (GPS) position data throughout an irrigation system having a plurality of connected spans and a plurality of drive towers for moving the connected spans about a central pivot having a pivot controller.

[0011] According to a second preferred embodiment, the present invention comprises a method for transmitting GPS real-time kinematic (RTK) correction signal data throughout an irrigation system having a plurality of connected spans and a plurality of drive towers for moving the connected spans about a central pivot having a pivot controller.

[0012] According to another preferred embodiment, the system of the present invention preferably further comprises a fixed RTK reference station that calculates GPS position errors using modulated signals transmitted over a power line carrier (PLC) system and transmits error correction data to one or more downstream GPS units that provide guidance to an irrigation machine such as the mobile GPS unit.

[0013] According to another preferred embodiment, the method of the present invention comprises the steps of: at a fixed (reference) station, receiving a first set of GPS position data and a second set of RTK data; comparing the first set of GPS position data with the second set of RTK data; calculating RTK error correction data; creating an RTK error correction data signal containing the RTK error correction data; modulating the RTK error correction data signal for transmission over a power line carrier; broadcasting the RTK error correction data signal over the power line through a power line bus (BUS) to the last drive tower; at a mobile (mobile) station, receiving the error correction data signal through the power line bus; demodulating the RTK error correction data signal; using the RTK error correction data to calculate the position of the mobile station.

[0014] According to another preferred embodiment, the last regular drive unit (LRDU) or corner drive tower can preferably include a GPS receiving unit, which preferably acts as a mobile (flowing) GPS unit that provides guidance signals to the corner drive tower or LRDU.

[0015] According to another preferred embodiment, the error correction data transmitted to the downstream mobile (flowing) GPS units at each drive unit can also be used to maintain the alignment of the irrigation machine components, such as the irrigation spans.

[0016] According to another preferred embodiment, the alignment can be maintained by calculating a straight centerline between the pivot and the last regular drive unit; calculating the relative distance between each intermediate drive tower and the calculated centerline; and controlling the speed or average run time of each intermediate drive tower to reduce the distance between the current position of each intermediate drive tower and the calculated centerline.

[0017] According to another preferred embodiment, the GPS units of the present invention can preferably further transmit GPS position data, including Wide Area Augmentation System corrected data, to a central control panel, which is typically located at the central pivot point or linear cart. According to another preferred embodiment, the position data of the present invention can preferably be used for various applications, such as opening or closing end gun sprayers depending on the movement of the central pivot through the field area requiring or not requiring water beyond the end of the structure; transmitting the position of the irrigation machine to the cloud for remote monitoring and control of the machine, such as reporting the position of the machine in the field; and various other needs, either in a local manner at the irrigation machine or in a remote manner (in the cloud or to a remote operator).

[0018] According to another preferred embodiment, the method of the present invention can include the steps of receiving a first set of GPS position data; modulating the GPS position data signal for transmission on a power line carrier; broadcasting the GPS position data signal over a power line bus onto the power line to a plurality of drive towers and a central control unit; demodulating the GPS position data signal at each drive tower and central control unit, and making the GPS position data available to the drive towers and central control unit.

[0019] According to another preferred embodiment, all of the GPS units on the PLC system can transmit the position data of the GPS units for use by other GPS units for various reasons, such as comparing the relative position between spans, calculating the relative angle between spans, calculating the relative height between drive units, and the rate of change of the angle and height, among others.

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various embodiments of the application and, together with the description, serve to explain the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 An exemplary irrigation system for use with the present application is shown.

[0022] Figure 2 A block diagram of an exemplary processing architecture of a control device in accordance with a first preferred embodiment of the present application is shown.

[0023] Figure 3 An irrigation system in accordance with another preferred embodiment of the present application is shown.

[0024] Figure 4 A block diagram in accordance with another preferred embodiment of the present application is shown.

[0025] Figure 5 A flowchart illustrating an exemplary method in accordance with a first preferred embodiment of the present application is shown.

[0026] Figure 6 A flowchart illustrating an exemplary method in accordance with a first preferred embodiment of the present application is provided. DETAILED DESCRIPTION

[0027] To facilitate an understanding of the principles of the present application, reference will now be made to the embodiments illustrated in the drawings, and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the application is intended by this specification, and that changes and further modifications can be anticipated with respect to such devices illustrated herein.

[0028] In accordance with preferred embodiments of the present application, it should be understood that the term "drive unit" can preferably include a number of subcomponents, including: an electric motor, a controller, a communication device (e.g., a PLC, etc.), and an alignment device. Furthermore, although the present application is discussed below with respect to four exemplary towers, the number of towers used can be expanded or reduced as desired (i.e., from 1 to 100 towers) without departing from the spirit of the present application. Moreover, the term "electric motor" as used herein can refer to any suitable electric motor for providing torque to the drive wheels. Thus, the term "electric motor" as used herein can preferably include electric motors such as switched reluctance motors, induction motors, etc.

[0029] The terms "program," "computer program," "software application," "module," "firmware," and the like as used herein are defined as a sequence of instructions designed for execution on a computer system. The term "solid state" should be understood to refer to a family of solid state electronic devices, which preferably include circuits or devices constructed from solid materials, and in which electrons or other charge carriers are entirely confined within solid materials. Exemplary solid components / materials can include crystals, polycrystalline and amorphous solids, electrical conductors and semiconductors. Common solid devices can include transistors, microprocessor chips, and RAM.

[0030] A program, computer program, module, or software application can include subprograms, functions, procedures, object implementations, executable applications, applets, servlets, source code, object code, shared libraries, dynamic load libraries, and / or other sequences of instructions designed for execution on a computer system. As defined herein, data storage devices include many different types of computer-readable media that allow a computer to read data from and write data to the medium, and hold the stored data in a manner that the computer can again read the data. Such data storage devices can include, for example, non-volatile memory, such as ROM, flash memory, battery-backed RAM, disk drive memory, CD-ROM, DVD, and other permanent storage media. However, even volatile storage devices such as RAM, buffers, cache memory, and network circuitry are contemplated as such data storage devices in accordance with different embodiments of the present application.

[0031] Aspects of the systems and methods described herein can be implemented as functionality programmed into any of a variety of circuitry, including programmable logic devices (PLDs), such as field programmable gate arrays (FPGAs), programmable array logic (PAL) devices, electronically programmable logic and memory devices, and standard cell-based devices, as well as application specific integrated circuits (ASICs). Some other possibilities for implementing aspects of the systems and methods include microcontrollers with memory, embedded microprocessors, firmware, software, and the like. Moreover, aspects of the systems and methods can be embodied in microprocessors having software-based circuit simulation, discrete logic (sequential and combinatorial), custom devices, fuzzy (neural network) logic, quantum devices, and hybrids of any of the above device types. Of course, the underlying device technologies can be provided in a variety of component types, e.g., metal oxide semiconductor field effect transistor (MOSFET) technologies like complementary metal oxide semiconductor (CMOS), bipolar technologies like emitter coupled logic (ECL), polymer technologies (e.g., silicon-conjugated polymer and metal-conjugated polymer-metal structures), bilateral junction transistors (TRIACs), analog and digital mixed technologies, etc.

[0032] As Figure 1As shown, the exemplary system 100 includes a cross member 101, which preferably includes a series of connected cross member sections that can be pressurized to facilitate the transfer of water from a water source through the irrigation system 100. A fluid source can be coupled to a reservoir or other source of agricultural product to inject fertilizers, pesticides, and / or other chemicals into the fluid in order to create an application for application during irrigation. Thus, the application can be water, fertilizer, herbicide, pesticide, combinations thereof, and the like. The exemplary system 100 can also include a main control panel 102 that can control transducers, sensors, and valves (not shown) to control and regulate water pressure to the sprinklers (not shown), which include end guns 136 and other sprinkler heads (not shown).

[0033] As further shown, the system can include drive towers 104, 106, 108, 110 with respective tower control boxes 120, 122, 124, 126. As further shown, these tower control boxes can be connected with respective alignment sensors 128, 130, 132, 134 and control respective drive unit motors 112, 114, 116, 118. As noted above, the system of the present application can include any motor suitable for providing torque to one or more drive wheels. According to one preferred embodiment, the system of the present application can preferably include a motor such as a switched reluctance motor, an induction motor, or the like.

[0034] Reference is now made to Figure 2An exemplary control device 138, which is representative of functionality to control one or more operational aspects of the irrigation system 100, will now be discussed. As shown, the exemplary control device 138 preferably includes a processor 140, a memory 142, a data storage module 150, and a network interface 144. The processor 140 provides processing functionality for the control device 138, and can include any number of processors, microcontrollers, or other processing systems. The processor 140 can execute one or more software programs that implement the techniques described herein. The memory 142, which is one example of a tangible computer readable medium, provides storage functionality to store various data associated with the operation of the control device 138, such as the software programs and code segments described above, or other data to instruct the processor 140 and other elements of the control device 138 to perform the steps described herein. The memory 142 can include, for example, removable and non-removable memory elements such as RAM, ROM, flash memory (e.g., SD card, mini-SD card, micro-SD card), magnetic, optical, USB memory devices, etc. The network interface 144 provides functionality to enable the control device 138 to communicate with one or more networks 149 through various components such as wireless access points, transceivers, etc., as well as any associated software (e.g., drivers, configuration software, etc.) employed by these components. As shown, the preferred systems of the present application can include a satellite transceiver 159 or the like for receiving direct satellite communications.

[0035] In embodiments, the exemplary control device 138 also preferably includes a power control system 145, a power line control (PLC) board 146, and a power line bus 147. According to one preferred implementation of the present application, the power line bus 147 preferably can include conductive transmission lines, circuitry, etc. for controlling and routing power, controlling power quality, and controlling devices attached to a power line carrier system, as discussed further below. According to another preferred implementation, the PLC board 146 preferably routes and converts power and data signals transmitted over the power line bus 147, as discussed further below.

[0036] In addition, the systems of the present application preferably can also include an irrigation location determination module 148, which can also include a global positioning system (GPS) receiver 157 or similar device for calculating the location of the irrigation system 100. According to another preferred implementation of the present application, the irrigation location determination module 148 preferably also includes a real-time kinematic (RTK) error calculation module 155, as discussed further below. According to preferred implementations, the processing of RTK signals as discussed herein can preferably be performed using single or dual frequency without limitation.

[0037] As further shown, the control device 138 can be coupled to a guidance device or similar system 152 (e.g., a turning assembly or turning mechanism) of the irrigation system 100 to control movement of the irrigation system 100 and assist in controlling movement and location awareness of the system. In addition, the control device 138 can also preferably include a plurality of inputs and outputs to receive data from sensors 154 and monitoring devices, as described below.

[0038] According to a preferred embodiment, the RTK error calculation module 155 preferably functions to perform RTK error calculations to enhance the accuracy of position data derived from the GPS system 157. Although the present application is discussed with respect to GPS, the present application is applicable to data received from other positioning systems such as LORAN, GLONASS, Galileo, BeiDou, and any combination of these and similar systems. Additionally, the RTK can utilize corrections with single frequency (commonly referred to as L1 band) or can utilize corrections with dual frequency (commonly referred to as L1 and L2 bands). Furthermore, similar correction techniques that enhance positioning accuracy (such as WAAS or differential GPS) can also be used. Preferably, any such system will be compatible with similar positioning systems described above and provide positioning accuracy better than 1 meter.

[0039] Reference is now made to Figure 3 An exemplary irrigation system 300 incorporating aspects of the present application will now be further discussed. As further shown, the exemplary irrigation system 300 can include transducers (not shown) provided to control and regulate water pressure to the sprinklers, including end guns 321 and other sprinkler heads 326.

[0040] In addition, the system can preferably include solid state tower boxes 312, 314, 316 (including PLC boards, solid state motor controllers, non-contact alignment devices, and other components as described above and further referenced below with respect to Figure 4 As further shown, the respective drive unit motors 307, 309, 311 preferably provide torque and braking to the respective drive wheel sets 302, 304, 306. As described above, the system of the present application can include any suitable motor for providing torque to the drive wheels. According to a preferred embodiment, the system of the present application can preferably include a motor such as a switched reluctance motor, an induction motor, or the like.

[0041] Further, the system 300 of the present application can preferably further comprise a control / hub panel 308 and elements such as GPS receivers 320a-d for receiving position data. Still further, the system of the present application can further comprise indirect crop sensors 318, 322, which can preferably include optional moisture sensors to determine moisture content in a given soil area. Additionally, the sensors 318, 322 can also include optics to allow detection of crop type, growth stage, health, presence of disease, growth rate, etc. Still further, the system can include ground sensors. Still further, the detection system can further receive data from connected weather stations or remote weather stations, etc. that measure weather characteristics such as humidity, wind speed, wind direction, pressure, precipitation, temperature, etc. Further, the preferred system of the present application can alternatively include additional elements mounted on the spanner 310 such as additional sensors, etc.

[0042] As Figure 3 Further shown, and as further discussed below, the preferred system of the present application can further comprise a Real Time Kinematic (RTK) reference station 328 for providing error correction data to GPS rover receivers that can be attached to a corner drive tower 325 or the like as further discussed below. Preferably, the RTK reference station 328 is positioned on a very precisely surveyed point. Still further, the RTK reference station 328 preferably receives GPS signals and calculates error correction data based on the difference in position between the surveyed location and the position data indicated by the measured GPS signals. According to another preferred embodiment, the last regular drive unit (LRDU), corner drive tower or cart can preferably comprise a GPS receiving unit 320d that preferably acts as a rover GPS unit.

[0043] Referring now to Figure 4 Once the RTK reference station 403 (alone and / or in combination with the hub controller 410 and the RTK error calculation module 155) creates error correction data, the error correction data is preferably transmitted by the hub controller 410 as an error correction data signal to the hub point PLC board 414. The hub point PLC board 414 then preferably modulates the error correction data signal and transmits the signal through the power line bus 416 and PLC system to one or more downstream GPS units / controllers 405, 407, 409. In this manner, each receiving GPS unit / controller of the present application receives enhanced RTK guidance. According to another preferred embodiment, the GPS units / controllers 405, 407, 409 of the present application can further send GPS position data to the hub controller 410 to provide additional position awareness.

[0044] According to another preferred embodiment, the RTK reference station 403 can preferably be located within a current collector / slip ring device 41 1 attached to the central pivot point. According to an alternative preferred embodiment, the location (longitude, latitude) of the RTK reference station can be set by any method known in the art. For example, the RTK reference station location can be manually set by user input of data collected from outside the system. Alternatively, the RTK reference station location can be set via a "survey mode" in which the position of the unit is determined by time-averaging GPS position data collected by the receiver using known algorithms.

[0045] Now further referring to Figure 4 The power / control system 400 of the present application can preferably include a control / pivot faceplate box 402 which preferably provides control signals and power to a series of intermediate solid state tower boxes 404, 406 and a last regular drive unit (LRDU) / trolley / flow tower box 408. As shown, each solid state tower box 404, 406, 408 also preferably includes a GPS sensor / input 405, 407, 409. It should be understood that the solid state tower boxes provided are by way of example and the present application is not intended to limit the use of solid state tower boxes. For example, electromechanical tower boxes can be used in place of solid state tower boxes without departing from the scope of the present application.

[0046] As further shown, the control / pivot faceplate box 402 of the present application can preferably include a master pivot controller 410 connected to a pivot point PLC board 414 which controls and directs power to the downstream intermediate solid state tower boxes 404, 406 and the corner drive tower / trolley / flow tower box 408. According to a preferred embodiment, the pivot controller 410 can be wired directly to the pivot point PLC board 414 or connected via a serial communication connection 412 (i.e. RS-232) or the like. According to a preferred embodiment, the pivot faceplate box 402 preferably provides power and control signals to the downstream solid state tower boxes 404, 406, 408 via a power line bus 416 through the pivot point PLC board 414.

[0047] According to one preferred embodiment, the power line bus 416 of the present application can provide and direct power at any of a variety of different voltages and amperages. For example, the power line bus 416 of the present application can provide power over a range of voltages (e.g., between 0 volts and 1000 volts) and a range of currents (e.g., between 0.1 amperes and 100 amperes) as needed without limitation. According to another preferred embodiment, power can be provided at a voltage of 120 volts to 480 volts, with the current being between 5 amperes and 50 amperes. For example, the power line bus 416 can provide 5 amperes, 120 volt AC power. According to another preferred embodiment, the power line bus 416 can preferably provide power at 30 amperes, 480 volt AC power. According to another preferred embodiment, the power line carrier of the present application can preferably operate as a one-way or two-way system.

[0048] As Figure 4 As further shown, RTK data is preferably first received by the RTK reference station 403, which can be located within the current collector 411 attached to the riser. Thereafter, the data is provided to the RTK error calculation module 155 to calculate and produce GPS error correction data. Thereafter, the RTK error calculation module 155 preferably transmits the RTK error correction data to the pivot point PLC board 414, where the signal is modulated and transmitted via the power line bus 416 (along with the power and control signals provided by the power line box 416) to the downstream solid tower boxes 404, 406, 408 and the pivot controller 410.

[0049] The error correction data signal is preferably first received by the first intermediate solid tower box 404, which preferably receives, processes and subsequently directs the received power to the central drive motor 418. In addition, the RTK error correction data is also preferably processed by the intermediate solid tower box 404 and used to correct / adjust the GPS position data received from the GPS module 405. Thereafter, the power and control signals can be further transmitted to one or more downstream tower boxes 406, which likewise process the received signals. Although not shown, any number of additional intermediate solid tower boxes can be added as needed depending on the size of the irrigation system. Regardless of the number of intermediate solid tower boxes, the RTK error correction data and the power from the power line bus 416 are preferably ultimately received at the corner drive tower box 408, which likewise preferably receives and processes the received RTK error correction data, as well as directs the received power to the central drive motor 422.

[0050] As Figure 4As further shown, the corner drive tower box 408 can preferably further include a GPS guidance control (GC) panel 413 for receiving and processing guidance control signals. Still further, the corner drive tower box 408 can preferably further include a PLC board 419 for receiving / transmitting and converting control and power signals between the tower box control panel 415 and other systems communicating over the power line bus 416, as further discussed below. In addition, each tower box 404, 406 can preferably further include similar PLC boards (not shown) to provide similar functionality.

[0051] In operation, the GC system 413 mounted at the end of the irrigation machine can preferably receive signals from GPS satellites via GPS sensor 409 or the like and calculate the position of the unit. As noted above, such calculations can include data from a Wide Area Augmentation System (WAAS) or the like. This data can then be transmitted to the PLC board 419 via any type of conventional wired connection, including being integrated onto the same circuit board as the GPS receiver. Thereafter, the PLC board 419 can then preferably transmit the GPS position data to the pivot point PLC board 414, which can demodulate the signal and send it to the main pivot controller 410, where the data can be used to indicate the position of the irrigation machine relative to the pivot point (i.e., distance, compass angle, etc.). The pivot controller 410 can then also report the position data to a cloud-based remote monitoring and control system via a communication system to allow a remote operator to know the positioning of the irrigation machine in the field. In addition, the pivot controller 410 can use the position data to activate or deactivate auxiliary sprayers based on the position of the irrigation machine. Still further, the pivot controller 410 can use the position data to adjust the speed of the machine and / or the pulse rate of the sprayers to comply with a variable rate irrigation prescription, as further discussed below. Still further, the pivot controller 410 can use the position data to make further calculations, such as calculating a slip rate or the like to detect a stuck machine.

[0052] Reference is now made to Figure 4 and Figure 5A preferred method 500 according to a preferred embodiment of the present application will now be discussed. According to a first preferred embodiment, GPS position data is preferably first received by a fixed (reference) station 403 at a first step 502. Alternatively, such data can be input from memory or received from an external network. According to one preferred embodiment, the GPS data is compared to a reference geographic position stored in the fixed (reference) station. Thereafter, at a next step 504, the stored geographic data and GPS data are then preferably processed by the RTK error calculation module 155 of the PLC board 414 to create RTK error correction data. At a next step 505, the pivot point PLC board 414 then preferably modulates the error correction data into a data signal that can be transmitted over the power line bus 416.

[0053] At a next step 507, this RTK error correction data is preferably transmitted to each of the downstream drive tower controllers 404, 406, and 408. Preferably, the data signal is transmitted over the power line bus 416 to one or more receiving PLC boards within the downstream tower box 404, 406, 408. According to one preferred embodiment, the LRDU PLC board 419 can receive the correction data and demodulate the received data signal. Thereafter, the PLC board 419 can preferably forward the correction data to the corner drive tower box controller 415 and / or the GC panel 413 for position refinement and other calculations. According to one preferred embodiment, the frequency of the corrected data transmission can be once per second. Alternatively, the corrected data can be transmitted at a faster or slower interval.

[0054] At a next step 508, the position of the corner drive tower 408 can be preferably calculated using the GPS data and the RTK error correction data. At a next step 510, the corner drive tower 408 can preferably calculate a distance adjustment (preferably using a bias error or path projection algorithm, etc.) and adjust the drive speed and / or direction to correct the drive tower position relative to the prescribed drive tower position. For example, the controller of each drive tower can control their drive wheels to reduce the distance between the current position of each drive tower and the desired guide path. This can be preferably accomplished by adjusting the duty cycle of a start-stop motor, by increasing or decreasing the RPM (revolutions per minute) of a variable speed motor (such as a switched reluctance motor or an induction motor driven by a variable frequency drive), or by similar methods.

[0055] According to an alternative preferred embodiment, each individual drive tower can increase or decrease its speed to reduce its own distance from the calculated centerline between the pivot point to the last drive tower, thereby maintaining a substantially straight alignment of the non-angled irrigation span. Preferably, any such calculations and / or adjustments of the drive towers of the present application can be performed continuously in real-time to maintain alignment during irrigation. Additionally, RTK correction signals can be transmitted preferably in real-time to allow each tower controller to correct for GPS errors in real-time.

[0056] According to an alternative preferred embodiment, the speed of the drive wheels can be controlled by adjusting or changing the programmed average speed of the drive wheels. Thus, the present application can continuously update the programmed average speed of each tower as needed, and can continuously cycle between position detection and updating of the programmed average speed of each tower to minimize misalignment of the towers.

[0057] According to a further preferred embodiment, the alignment algorithm of the present application can be operated while the machine is stationary or during operation of the irrigation system. Furthermore, the algorithm and system of the present application can be used to initially align the towers each time the machine is started (i.e., at the beginning of machine movement) rather than during machine movement. According to a further preferred embodiment, the algorithm of the present application can preferably include a margin error so as to only instruct towers that are located more than a set distance (i.e., two inches) from a given centerline to reduce the detected alignment error. According to a further preferred embodiment, the order of alignment can be determined in order from the outermost tower to the innermost tower. Furthermore, the order of priority for re-alignment of the towers can be determined from the outermost tower to the innermost tower.

[0058] Reference will now be made to Figure 4 and Figure 6 An alternative alignment method 600 for the present application will now be discussed. According to one exemplary alternative algorithm, in a preferred first step 602, the pivot controller 410 of the present application preferably receives a first set of GPS position data. According to one preferred embodiment, the GPS data can be received directly by a GPS satellite receiver. Alternatively, such data can be input from memory or received from an external network.

[0059] In a next step 604, the pivot controller 410 preferably compares the GPS position data to a reference geographic position stored in a fixed (reference) station. In a next step 606, the pivot controller 410 preferably calculates RTK error correction data. In a next step 608, the RTK error correction data is preferably transmitted to each downstream drive tower controller 404, 406, 408 via a power line carrier network.

[0060] In a next step 610, each tower control unit can preferably broadcast the corrected position data to adjacent drive tower controllers. According to one preferred embodiment, each tower control unit can transmit the corrected position data via a connected PLC board. According to an alternative preferred embodiment, the corrected position data can be transmitted directly between drive tower controllers, or can first be transmitted to a central pivot point controller 410, which can then store the position data and transmit the position data to each drive controller over a PLC bus 416. In a next step 612, each pair of adjacent towers can preferably use the corrected position data to calculate a straight, centerline between them. In a next step 614, the drive towers can calculate their relative distance to the calculated centerline. In a next step 616, the controller of each drive tower can then control the drive wheel sets to reduce the distance between the current position of the drive wheels and the calculated centerline. For example, the electric motors can preferably be controlled to increase their speed in order to reduce the distance between themselves and the centerline as the irrigation machine travels in a given direction, thus reducing the angular offset between the drive towers.

[0061] Preferably, multiple sets of towers can act simultaneously to align themselves and continuously update the centerline. For example, the system can preferably analyze and align multiple three-tower sets simultaneously. Furthermore, "three-tower alignment" can preferably be performed along the machine on each tower, starting with the tower closest to the end tower and then working inwards. Alignment can preferably be performed simultaneously between all towers. Additionally, the pivot controller 410 can preferably continuously send real-time kinematic (RTK) signals to all downstream towers to allow each tower controller to correct for GPS errors and calculate corrected position data.

[0062] According to another preferred embodiment, all towers can be continuously aligned until all "delta" lengths are within a certain threshold for alignment. During the alignment process, the end towers can preferably be moved in a manner that minimizes stress on the cross members. According to other aspects of the present application, it is understood that the use of three-tower sets as discussed above is provided only as a preferred example. Alternatively, any other number of towers can also be used as sets.

[0063] According to one alternative embodiment, the present application can use analog sensors on each tower. For example, LORAN devices can be located on each tower, and then the system can use a three-tower alignment algorithm, for example, in conjunction with triangulation data from the LORAN devices. Furthermore, LORAN can also be used as a backup to GPS sensors in the event that the GPS sensors fail or become unavailable.

[0064] According to another preferred embodiment, the GPS sensor of the present application can preferably be placed as low as possible from the ground. Furthermore, when the GPS sensor needs to be placed at a higher position on the tower, any tracking errors caused by the terrain can preferably be corrected or compensated for by utilizing the inclinometer and / or gyroscope sensor data of the GPS sensor at the tower. In this case, the GPS coordinates reported by the sensor can be adjusted based on the amount of tilt in the tower (due to terrain slope) as measured by the co-installed inclinometer and / or gyroscope sensors. Alternatively, if the GPS sensor is installed close to the tower's piping, no compensation for terrain-induced tilt is necessary.

[0065] While the above description of the present application contains many specifics, these should not be construed as limitations on the scope of the application, but rather as exemplifications of one preferred embodiment thereof. Many other variations are possible. For example, the processing elements of the present application can operate at many different frequencies, voltages, amperages and bus configurations, by the present application. Also, the communications provided by the present application can be designed to be duplex or simplex, as the case can be. Furthermore, the system of the present application can be used with any arrangement of drive towers, including both linear and central pivot systems. Also, the processes of transmitting data to and from the present application can be designed to be push or pull, as the case can be. Still further, each feature of the present application can be made remotely activated and accessible from a remote monitoring station. Thus, data can be uploaded to and downloaded from the present application, as the case can be.

[0066] Accordingly, the scope of the present application should be determined not by the illustrated embodiments, but by the appended claims and their legal equivalents.

Claims

1. A method for aligning jumpers using real-time dynamic (RTK) data transmitted via a power line carrier system, wherein, The system includes multiple connected jumpers and multiple drive towers for moving the connected jumpers around a central pivot with a pivot controller; wherein each drive tower includes a power line carrier node; furthermore, the drive towers include intermediate drive towers and final drive towers; and furthermore, the system includes a fixed reference station for storing reference position data. The method includes: Receive the first set of GPS location data; The first set of GPS location data is compared with the reference location data stored in the fixed reference station; Calculate RTK error correction data; Create RTK error correction data signals; The RTK error correction data signal is modulated for transmission on a power line carrier; wherein the power line carrier includes a plurality of conductive elements configured to connect and transmit signals to the power line bus, and to connect and transmit signals from the power line bus; The RTK error correction data signal is transmitted via the power line bus to the power line carrier node of each drive tower. At each of the drive towers, the RTK error correction data signal is demodulated and the demodulated RTK error correction data is used to calculate the corrected position data; The controller of each drive tower broadcasts the corrected position data to the controllers of the adjacent drive towers; The centerline between each pair of adjacent drive towers is calculated using calibrated position data. Calculate the relative distance from each drive tower in each pair of adjacent drive towers to the calculated centerline; The controller of each drive tower in each pair of adjacent drive towers controls the drive wheel assembly to reduce the distance between the current position of the drive tower and the calculated centerline.

2. The method according to claim 1, wherein, The first set of GPS location data is input from a memory; furthermore, the speed of each intermediate drive tower is controlled by reducing the average running time of each intermediate drive tower, thereby reducing the distance between the current position of each intermediate drive tower and the calculated centerline.

3. The method according to claim 1, wherein, The plurality of drive towers also includes an angle drive tower, and the method further includes: demodulating the RTK error correction data signal at the angle drive tower; The position of the angle drive tower is calculated using the RTK error correction data; The calculated position of the corner drive tower is compared with the target position of the corner drive tower; wherein the comparison step includes: calculating the distance between the calculated position of the corner drive tower and the target position of the corner drive tower; wherein the distance is calculated using a linear regression algorithm; and The speed of the corner drive tower is controlled to reduce the distance between the calculated position of the corner drive tower and the target position of the corner drive tower.

4. The method according to claim 3, wherein, The calculation is performed using a bias error algorithm.

5. The method according to claim 3, wherein, The calculation is performed using a path projection algorithm.

6. The method according to claim 3, wherein, The distance between the calculated position of the angle drive tower and the target position of the angle drive tower is reduced by adjusting the duty cycle of the start-stop motor.

7. The method according to claim 3, wherein, The distance between the calculated position of the angle drive tower and the target position of the angle drive tower is reduced by changing the RPM of the variable speed motor.

8. The method according to claim 1, wherein, The RTK error correction data signal is transmitted in near real-time to allow each tower controller to correct GPS errors in real time.

9. The method according to claim 3, wherein, The distance between the calculated position of the cornering drive tower and the target position of the cornering drive tower is reduced by changing the average speed of the programmed drive tower drive wheels.

10. The method according to claim 1, wherein, Multiple pairs of adjacent drive towers work simultaneously to align themselves and continuously update the centerline.

11. An irrigation system comprising a plurality of connected jumpers and a plurality of drive towers, the plurality of drive towers being configured to move the connected jumpers about a central pivot having a pivot controller, the irrigation system comprising: A tower control panel, wherein the tower control panel includes a first PLC board; An RTK reference station, wherein the RTK reference station is configured to receive RTK data; wherein the RTK reference station is located within the collector ring of a riser attached to the central pivot. An RTK error calculation module is configured to receive the RTK data and generate GPS error correction data; wherein the RTK error calculation module is configured to transmit the GPS error correction data to the first PLC board. The first PLC board is configured to modulate and transmit an RTK error signal including the GPS error correction data; the first PLC board is configured to output power and control signals to multiple downstream solid-state tower boxes. A first tower box, wherein the first tower box is a solid-state tower box configured to control the operation of a first drive tower, wherein the first tower box is configured to receive the RTK error signal, power and control signal from the first PLC board; wherein the first tower box is configured to direct the received power to the first tower drive motor; The second tower box is a solid-state tower box configured to control the operation of a second drive tower, wherein the second tower box is configured to receive the RTK error signal, power and control signal from the first PLC board; wherein the second tower box is configured to direct the received power to the second tower drive motor. The third tower box is a solid-state tower box configured to control the operation of a third drive tower. The third tower box is configured to receive the RTK error signal, power signal, and control signal from the first PLC board. The third tower box is configured to direct the received power to the third tower drive motor. An angle tower box, wherein the angle tower box is a solid-state tower box configured to control the operation of an angle drive tower, wherein the angle tower box is configured to receive the RTK error signal, power and control signal from the first PLC board; wherein the angle tower box is configured to direct the received power to the angle tower drive motor; The corner tower box includes a second PLC board and a guide control panel; the second PLC board is configured to receive power and control signals from the first PLC board; the guide control panel is configured to receive GPS sensor data and the RTK error signal; the second PLC board is configured to use the RTK error signal to generate corner tower position data; and the second PLC board is configured to transmit the corner tower position data to the first PLC board. The first drive tower, the second drive tower, the third drive tower, and the corner drive tower can be configured to transmit and receive calibrated position data from one or more adjacent drive towers. Wherein, the first drive tower is adjacent to the second drive tower, the second drive tower is adjacent to the third drive tower, and the third drive tower is adjacent to the corner drive tower; The first pair of adjacent drive towers is configured to independently calculate the distance to the centerline between the first pair of adjacent drive towers using position data corrected by the RTK error signal; wherein the first pair of adjacent towers is configured to allocate only one of the two adjacent drive tower boxes to control the drive wheel assembly to reduce the distance between the current position and the calculated centerline.

12. The irrigation system according to claim 11, wherein, The location of the irrigation machine is calculated using data from the Wide Area Augmentation System (WAAS) at least in part.

13. The irrigation system according to claim 11, wherein, The pivot controller is configured to transmit the angle tower position data to a remote, cloud-based monitoring and control system.

14. The irrigation system according to claim 12, wherein, The pivot controller is configured to control one or more sprayers using the corner tower position data based on the position of the irrigation machine.

15. The irrigation system according to claim 11, wherein, The pivot controller is configured to use the angle tower position data to adjust the speed of the irrigation machine.

16. The irrigation system according to claim 11, wherein, The pivot controller is configured to use the angle tower position data to control the pulse rate of the sprayer to conform to the variable rate irrigation prescription.

17. The irrigation system according to claim 11, wherein, The pivot controller is configured to use the corner tower position data to calculate the slip ratio of the drive tower.

18. The irrigation system according to claim 11, wherein, The system also includes multiple alignment groups; wherein a first alignment group includes multiple drive towers; wherein the first alignment group is configured to coordinate the alignment of the multiple drive towers within the first alignment group independently of instructions from the tower control panel.

19. The irrigation system according to claim 18, wherein, The first alignment group includes three drive towers; wherein the first alignment group is configured to transmit alignment data between the first alignment group tower boxes; wherein the first alignment group is configured to align each of the three drive towers along a centerline calculated by the first alignment group tower boxes.

20. The irrigation system according to claim 19, wherein, The plurality of alignment groups are configured to align sequentially based on the distance of the plurality of alignment groups from the central pivot.

21. The irrigation system according to claim 20, wherein, The alignment group furthest from the central pivot is configured to align before the alignment group closest to the central pivot.

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