Inductively coupled distributed control system

• US 9,128,489 B2
• Filed: 02/08/2011
• Issued: 09/08/2015
• Est. Priority Date: 02/09/2010
• Status: Active Grant

• Current Assignee: Nelson Irrigation Corporation
• Original Assignee: Nelson Irrigation Corporation
• Inventors: Bauman, Mark A., Young, Tom J., Nelson, Craig B., Leinweber, Chad D.
• Primary Examiner(s): Lim, Steven
• Assistant Examiner(s): Adnan, Muhammad
• Application Number:
  US13/022,796
• Publication Number:
  US 20110196541A1
• Time in Patent Office: 1,673 Days
• Field of Search: 340/12.32, 340/12.38, 340/13.23, 340/538.16, 455/41.1
• US Class Current: 1/1
• CPC Class Codes: G05B 19/0421 Multiprocessor system
• CPC Class Codes: G05B 2219/25356 Inductive coupling of power and signal
• CPC Class Codes: G05D 7/06 characterised by the use of electric means G05D7/005 takes precedence

Abstract

A distributed control system is provided wherein a master controller inductively delivers power and data to a plurality of remote slave modules or controllers via a plurality of coupling loops formed along a length of transmission line. Each of the remote slave modules, in turn, inductively delivers return data to the master controller via the plurality of coupling loops. The use of inductive coupling provides an advantage over the state of the art because no direct galvanic electrical connection is required between the transmission line and the remote slave modules which promise to simplify installation and enhance long-term reliability. Example applications for the control system described herein include agricultural irrigation systems where individual sprinkler and valve components may be controlled collectively, individually, or in groups or subsets, to vary application rates according to prescribed irrigation parameters.

Claims

1. A distributed control system comprising:

a master controller connected to a transmission line and adapted to deliver power and data to the transmission line and to receive data from the transmission line;

said transmission line comprised of first and second conductors configured to carry differential data and power, wherein the electromagnetic fields generated by the first and second conductor are out of phase with each other along the transmission line; and

a plurality of inductive couplers arranged along the transmission line and remain stationary with respect to the transmission line while the line carries the power and data, each inductive coupler enclosing an inductive coupling loop formed by arranging one of the first and second conductors to follow a clockwise path and by arranging other one of the first and second conductors to follow a counter-clockwise path, each inductive coupling loop comprising the first and second conductors passing through a single core opening in a respective one of said inductive couplers to thereby establish mutual coupling between the transmission line and an inductive coupler coil, wherein the first conductor passes once through the single core opening, and the second conductor forms a loop of equal to or greater than three hundred and sixty degrees that passes through the single core opening, and said inductive coupler coil is connected to one or more slave controllers;

wherein said mutual coupling permits data transfer from the master controller to the one or more slave controllers and from the one or more slave controllers to the master controller, and

wherein said mutual coupling transfers power from the transmission line to the one or more slave controllers.

2. The distributed control system of claim 1 wherein the one or more slave controllers utilize solenoids to control one or more sprinkler components.

3. The distributed control system of claim 1 wherein said inductive coupler, for each of the one or more slave controllers, comprises first and second split core portions joined to form a toroidal core defining said single core opening through which said inductive coupling loops pass, and wherein one of the first and second split core portion is wound with said inductive coupler coil.

4. The distributed control system of claim 3 wherein said first and second split core portions are composed of powdered ferrite material.

5. The distributed control system of claim 1 wherein said master controller includes at least one microcontroller connected to a user interface permitting an operator to configure and operate the distributed control system.

6. The distributed control system of claim 1 wherein a switch controlled by said master controller determines when data is transmitted to said one or more slave controllers, and when data is received from said one or more slave controllers.

7. The distributed control system of claim 3 wherein each of said one or more slave controllers includes a circuit board supporting said first and second split core portions and said inductive coupling loops.

8. The distributed control system of claim 7 and further comprising a housing enclosing said circuit board, said first and second split core portions and said inductive coupling loops.

10. The distributed control system of claim 8 wherein said one or more slave controllers comprise plural slave controllers secured, respectively, to base components of sprinklers arranged along a water supply conduit.

11. The distributed control system of claim 1 wherein said one or more slave controllers comprise plural slave controllers secured, respectively, on drop hoses connected to an overhead truss of a linear or pivot irrigation machine, each drop hose supporting a sprinkler controlled by one of said plural slave controllers.

12. The distributed control system of claim 1 wherein said one or more slave controllers comprise plural slave controllers mounted along an overhead truss of a linear or pivot irrigation machine, with plural drop hoses suspended from said overhead truss, said plural drop hoses each supporting a sprinkler controlled by a respective one of said plural slave controllers.

13. The distributed control system of claim 1 wherein said inductive coupling loops are circular, substantially 360 degree closed loops.

9. The distributed control system of claim wherein said housing comprises a lower body portion and an upper cover portion, said upper cover portion is moveable between open and closed positions, and wherein said first split core portion and said inductive coupling loops are supported in said upper cover portion, and wherein said second split core portion and the coil are supported in said lower body portion.

14. A coupler assembly for electrically coupling a coupling loop formed using a first and second conductor from a transmission line and a slave controller, wherein electromagnetic fields generated by the first and second conductor are out of phase with each other along the transmission line, the coupler assembly comprises:

a housing including a first body portion and a second body portion,

a split core,

a winding or coil around the split core is conductively coupled to a slave controller;

the coupling loop including the first conductor arranged along a clockwise path and the second conductor arranged along a counter-clockwise path and the first conductor passes once through an opening of the split core and the second conductor forms a loop of equal to or greater than three hundred and sixty degrees that passes through opening of the split core, and;

wherein said second body portion is moveable relative to the first body position between open and closed positions, and

wherein a first half of the split core and the coupling loop is supported in said second body portion,

wherein a second half of the split core and a coil are supported in said first body portion,

wherein a mutual coupling between the coupling loop and the winding or coil transfers electrical power and data between the transmission line and the slave controller, and

wherein the coupler assembly remains stationary with respect to the transmission line while the line carries the power and data.

15. The inductive coupler assembly of claim 14 wherein said first body portion incorporates a slave controller circuit board supporting said second half of the split core and coil.

16. The inductive coupler assembly of claim 14 wherein said inductive coupling loops are circular, substantially 360°

closed loops.

17. A method of controlling a plurality of sprinklers in an irrigation system that includes a master controller for controlling a plurality of slave controllers each operatively connected to one or more of said plurality of sprinkler components, the method comprising:

(a) providing a transmission line having a first and second conductor, wherein electromagnetic fields generated by the first and second conductor are out of phase with each other along the transmission line;

(b) forming a plurality of coupling loops along the transmission line, wherein each coupling loop is formed by arranging the first and second conductors of the transmission line in a loop so that one of the first and second conductors follows a clockwise path and the other of the first and second conductors follows a counter-clockwise path;

(c) coupling each of said coupling loops to a respective one of said slave controllers by passing said coupling loop through a single core of an inductive coupler connected to the respective one of the slave controllers, wherein each single core includes a coupling loop passing once through the core and another coupling loop that extends equal to or greater than three hundred and sixty degrees; and

(d) sending electrical power and data signals over said transmission line from said master controller to said plurality of slave controllers, wherein the power and data signals are inductively transferred through the inductive coupling of each of the coupling loops to the respective one of the slave controllers, wherein the coupling loops remain stationary with respect to the transmission line while the line carries the power and data.

18. A distributed control comprising:

a master controller connected to a transmission line and adapted to deliver power and data to the transmission line;

said transmission line comprised of first and second conductors configured to carry differential data, wherein electromagnetic fields generated by the first and second conductor are out of phase with each other along the transmission line;

a plurality of coupling loops distributed along the transmission line, wherein each coupling loop includes one of the first and second conductors arranged in a clockwise path and the other of the first and second conductors arranged in a counter-clockwise path; and

a plurality of inductive couplers enclosing each of the respective coupling loops, each inductive coupler comprising a core having a single opening to thereby establish mutual coupling between the transmission line and to one or more slave controllers, wherein each of the cores has one of the respective coupling loops passing once through the single opening and another of the respective coupling loops extending equal to or greater than three hundred and sixty degrees around the core, and;

wherein said mutual coupling permits data transfer from the master controller to the one or more slave controllers and transfers electrical power from the transmission line to each of the slave controllers, and

each of the coupling loops remain stationary with respect to the transmission line while the line carries the power and data.

19. The distributed control system of claim 18 wherein the one or more slave controllers utilize solenoids to control one or more sprinkler components.

20. The distributed control system of claim 18 wherein said inductive coupler comprises first and second split core portions joined to form a toroidal core defining said single core opening through which said coupling loops pass, and wherein one of the first and second split core portion is wound with said inductive coupler coil.

21. The distributed control system of claim 18 wherein said one or more slave controllers comprise plural slave controllers secured, respectively, to base components of sprinklers arranged along a water supply conduit.

22. The distributed control system of claim 18 wherein said one or more slave controllers comprise plural slave controllers secured, respectively, on drop hoses connected to an overhead truss of a linear or pivot irrigation machine, each drop hose supporting a sprinkler controlled by one of said plural slave controllers.

23. The distributed control system of claim 18 wherein said one or more slave controllers comprise plural slave controllers mounted along an overhead truss of a linear or pivot irrigation machine, with plural drop hoses suspended from said overhead truss, said plural drop hoses each supporting a sprinkler controlled by a respective one of said plural slave controllers.