Optimization of irrigation cycles

• US 6,618,673 B2
• Filed: 02/22/2002
• Issued: 09/09/2003
• Est. Priority Date: 03/04/2001
• Status: Expired due to Fees

• Current Assignee: C I T Controlled Irrigation Technologies Limited
• Original Assignee: Benjamin Zur
• Inventors: Zur, Benjamin
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): Taylor, Victor J.
• Application Number:
  US10/081,581
• Publication Number:
  US 20020165700A1
• Time in Patent Office: 564 Days
• Field of Search: 702/2, 702/188, 702/16, 405/37, 405/229, 137/78.3, 137/78.2, 137/1, 73/73, 700/16, 239/63
• US Class Current: 702/2
• CPC Class Codes: A01G 25/165 Cyclic operations, timing systems, timing valves, impulse operations

Abstract

A method for the optimization of irrigation of an area by a plurality of successive adaptive irrigation cycles is disclosed. The method is implemented as a system including an irrigation water controller, a probe for sensing a wetting-front depth, a computerized irrigation cycler, and a computer program running on the cycler. For the first irrigation cycle, input parameters related to the soil and to the wetting front arrival are entered either by default or manually. Data collected during the first irrigation cycle is used for the adaptive optimization of the following irrigation cycles. The steps of the computer program and the wetting-front detection probe are described.

Claims

1. A system for irrigation of an area by a plurality of successive adaptive irrigation cycles starting with a first irrigation cycle, the system comprising:

an irrigation controller for initiating and stopping irrigation in response to signals,

a probe having sensors for detecting arrival of a wetting front, the probe providing signals associated with the detected wetting front depth,

a cycler comprising a processor, a memory and an I/O unit, the cycler being coupled to the irrigation controller for emitting signals thereto, and the cycler being coupled to the probe for emitting and for receiving signals therefrom,

a computer program preloaded in the memory of the processor and running on the processor, the processor controlling adaptive irrigation and managing successive irrigation cycles, and the computer program comprising;

a predetermined threshold limit Δ

R, and

a predetermined ratio G₁ representing soil texture characteristics.

2. The system according to claim 1, wherein the computer program further comprises:

a first initial wetting front depth value Z_I1 to initiate and stop the first irrigation cycle, and

a procedure for beginning the first adaptive irrigation cycle to be followed by a plurality of successive adapted irrigation cycles.

3. The system according to claim 1, wherein both the predetermined threshold limit Δ

R and the ratio G₁ are selected, in combination, from the group consisting of preset default values and of user-selected inputs.

4. The system according to claim 1, wherein the computer program further comprises:

a first set of instructions for performing preliminary setup for the first irrigation cycle, and

a second set of instructions for initiating irrigation, for tracking a wetting front depth and for stopping irrigation.

5. The system according to claim 1, wherein the computer program comprises:

a third set of instructions for deriving information from a preceding irrigation cycle and for adapting instructions for application to a next irrigation cycle, and

a fourth set of instructions for beginning the next irrigation cycle and returning to the second set of instructions.

6. The system according to the claim 4, wherein the first set of instructions further comprises:

a first initial wetting front depth instruction for the first irrigation cycle i=1, for calculating a first initial wetting front depth Z_Ii, to stop irrigation, by the equation Z_Ii=G_i*Z_Fi., where Z_F is a final wetting front depth input value selected for optimal irrigation.

7. The system according to claim 4, wherein the second set of instructions comprises:

an irrigation start instruction sent by the processor to the irrigation controller for commanding the irrigation controller to start an irrigation cycle,

a tracking instruction for tracking the wetting front depth by deriving wetting front depth signals from the probe,

a detection instruction for detecting a depth signal received by the processor from the probe, the depth signal indicating arrival of the wetting front to the initial depth of irrigation, and

an irrigation stop instruction sent by the processor to the irrigation controller, the stop signal for commanding the irrigation controller to stop irrigation of an irrigation cycle.

8. The system according to the claim 4, wherein the third set of instructions comprises:

a drainage pause instruction commanding an irrigation pause for a duration relative at least to the soil texture ratio G_i adapted by the irrigation cycle,

an actual depth Z_F instruction commanding the processor to derive from the probe an actual derived drainage depth Z_F of the wetting front,

a comparison instruction for commanding the processor to compare an actually derived drainage depth of the wetting front Z_F with the selected final drainage wetting front depth value Z_Fi,

a recalculation instruction for calculating an adapted initial wetting front depth Z_Ii, if the actual derived depth of the wetting front Z_F differs for more than a predetermined margin from the final drainage depth Z_F1, the recalculation instruction adapting the soil texture ratio G_i and the initial depth of irrigation Z_Ii for a next irrigation cycle, and

a continue instruction for the third set of instructions to continue to the fourth set of instructions when the actual derived depth of the wetting front Z_F does not differ for more than a predetermined margin from the final drainage depth Z_F1.

9. The system according to claim 4, wherein the fourth set of instructions comprises:

a dwell instruction commanding the processor to dwell between successive irrigation cycles, the dwell lasting for a duration relative to at least the adapted ratio G_i, and

an increment instruction commanding the cycler to raise the irrigation cycle number by one and to return to the second set of instructions for starting a next irrigation cycle.

10. A probe for detecting an irrigation wetting-front depth, the probe operating in association with a processor commanding irrigation cycles started and ended by an irrigation controller, the probe comprising:

a monolithic slender dielectric body having a generally smooth symmetrical external surface and a length defining a longitudinal axis, the body extremities consisting of a forward end having a tapered tip and of a rearward end having a head,

a plurality of spaced apart parallel thin electrically conductive electrodes accommodated flush with and girdling the external surface of the probe in perpendicular to and in distribution along the longitudinal axis, and

a circuitry embedded inside the body of the probe, the circuitry including a plurality of electrical leads at least equal in number to the plurality of conductive electrodes, the electrical leads being arranged adjacent the external surface, parallel to the longitudinal axis and in equally distant radial distribution relative thereto, the electrical leads being electrically coupled to the conductive electrodes and the circuitry being coupled to the processor, for the processor to sample the circuitry and derive a wetting-front depth across one pair of conductive electrodes selected out of the plurality of conductive electrodes.

11. The probe according to claim 10, further comprising:

a coupling electrically linking each single one conductive electrode out of the plurality of conductive electrodes to only one electrical lead out of the plurality of electrical leads.

12. The probe according to claim 10, further comprising:

an insulation for electrically insulating each single one conductive lead out of the plurality of conductive electrodes coupled to one out of the plurality of conductive leads.

13. The probe according to claim 10, wherein

each pair of two adjacent conductive electrodes out of the plurality of conductive electrodes is amenable to form a sensor and to be sampled by the processor.

14. The probe according to claim 10, wherein

the plurality of conductive electrodes is grouped in sets, each set including one pair of adjacent conductive electrodes, and each set being amenable to form a sensor and to be sampled by the processor.

15. The probe according to claim 10, wherein

any pair of conductive electrodes out of the plurality of conductive electrodes is amenable to form a sensor and to be sampled by the processor.

16. The probe according to claim 10, wherein

the plurality of electrodes is configured for detecting change in soil properties to detect arrival of a wetting front by use of a detection method, selected from the detection methods including impedance, capacitance, radiation and resistance.

17. The probe according to claim 10, wherein

the plurality of conductive electrodes contacts the soil when the probe is inserted in the ground.

18. The probe according to claim 10, wherein the monolithic slender dielectric body is made from plastic material.

19. The probe according to claim 10, wherein the monolithic slender dielectric solid body is extruded.

20. A method for irrigation of an area by a plurality of successive adaptive irrigation cycles starting with a first irrigation cycle, the method comprising the steps of:

initiating and stopping irrigation with an irrigation controller responsive to signals,

detecting arrival of a wetting front with a probe having sensors, the probe providing signals associated with the detected wetting front depth,

operating a cycler comprising a processor, a memory and an I/O unit, the cycler being coupled to the irrigation controller for emitting signals thereto, and the cycler being coupled to the probe for emitting and for receiving signals therefrom,

running on the processor a computer program preloaded in the memory of the processor, the processor controlling adaptive irrigation and managing successive irrigation cycles, the computer program comprising;

a predetermined threshold limit Δ

R, and

a predetermined ratio G₁ representing soil texture characteristics.

21. The method according to claim 20, wherein running the computer program further comprises the steps of:

using a first initial wetting front depth value Z_I1 to initiate and stop the first irrigation cycle, and

running a procedure for beginning the first adaptive irrigation cycle to be followed by a plurality of successive adapted irrigation cycles.

22. The method according to claim 20, wherein both the predetermined threshold limit Δ

R and the ratioG₁ are selected, in combination, from the group consisting of preset default values and of user-selected inputs.

23. The method according to claim 20, wherein the computer program further comprises the steps of:

running a first set of instructions for performing preliminary setup for the first irrigation cycle, and

running a second set of instructions for initiating irrigation, for tracking a wetting front depth and for stopping irrigation.

24. The method according to claim 20, wherein running the computer program comprises the steps of:

running a third set of instructions for deriving information from a preceding irrigation cycle and for adapting instructions for application to a next irrigation cycle, and

running a fourth set of instructions for beginning the next irrigation cycle and returning to the second set of instructions.

25. The method according to the claim 23, wherein the first set of instructions further comprises the steps of:

using a first initial wetting front depth instruction for the first irrigation cycle i=1, for calculating a first initial wetting front depth Z_Ii, to stop irrigation, by the equation Z_Ii=G_i*Z_Fi, where Z_F is a final wetting front depth input value selected for optimal irrigation.

26. The method according to claim 23, wherein the second set of instructions comprises the steps of:

detecting an irrigation start instruction sent by the processor to the irrigation controller for commanding the irrigation controller to start an irrigation cycle, a tracking instruction for tracking the wetting front depth by deriving wetting front depth signals from the probe,

inserting a detection instruction for detecting a depth signal received by the processor from the probe, the depth signal indicating arrival of the wetting front to the initial depth of irrigation, and

reading an irrigation stop instruction sent by the processor to the irrigation controller, the stop signal for commanding the irrigation controller to stop irrigation of an irrigation cycle.

27. The method according to the claim 23, wherein the third set of instructions comprises the steps of:

executing a drainage pause instruction commanding an irrigation pause for a duration relative at least to the soil texture ratio G_i adapted by the irrigation cycle,

reading an actual depth Z_F instruction commanding the processor to derive from the probe an actual derived drainage depth Z_F of the wetting front,

implementing a comparison instruction for commanding the processor to compare an actually derived drainage depth of the wetting front Z_F with the selected final drainage wetting front depth value Z_Fi,

calculating an adapted initial wetting front depth Z_Ii, with a recalculation instruction if the actual derived depth of the wetting front Z_F differs for more than a predetermined margin from the final drainage depth Z_F1, the recalculation instruction adapting the soil texture ratio G_i and the initial depth of irrigation Z_Ii for a next irrigation cycle, and

applying a continue instruction for the third set of instructions to continue to the fourth set of instructions when the actual derived depth of the wetting front Z_F does not differ for more than a predetermined margin from the final drainage depth Z_F1.

28. The method according to claim 24, wherein the fourth set of instructions comprises:

executing a dwell instruction commanding the processor to dwell between successive irrigation cycles, the dwell lasting for a duration relative to at least the adapted ratio G_i,, and

effecting an increment instruction commanding the cycler to raise the irrigation cycle number by one and to return to the second set of instructions for starting a next irrigation cycle.