Method and apparatus for the automatic regulation of the irrigation of plants

• US 8,862,276 B2
• Filed: 08/19/2009
• Issued: 10/14/2014
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: PlantCare AG
• Original Assignee: PlantCare AG
• Inventors: Schmidt, Walter, Toprak, Yucel
• Primary Examiner(s): Ali, Mohammad
• Assistant Examiner(s): Karim, Ziaul
• Application Number:
  US13/062,223
• Publication Number:
  US 20110238226A1
• Time in Patent Office: 1,882 Days
• Field of Search: 700/284, 700/63, 700/14, 307/118, 137/78, 239/70
• US Class Current: 700/284
• CPC Class Codes: A01G 25/167 Control by humidity of the soil itself or of devices simulating soil or of the atmosphere; Soil humidity sensors
• CPC Class Codes: A01G 27/003 Controls for self-acting watering devices
• CPC Class Codes: G05B 11/011 details of the correcting means
• CPC Class Codes: G05D 7/0629 characterised by the type of regulator means

Abstract

A method for the automatic irrigation of plants, wherein the temporal progression of soil moisture is determined from measured soil moisture values, and said progression is used for the calculation of an optimized irrigation time duration, such that both water excess in the soil and soil drying are avoided as much as possible. Preferably, the time duration of irrigation is constantly evaluated and optimized using comparisons of measured values with prespecified moisture- and dryness threshold values (GWmoist, GWdry), and automatically adjusted to changing environmental conditions and/or plant requirements.

Claims

1. A method for the regulation and control of an irrigation device, the method comprising:

measuring soil moisture using a sensor to obtain moisture values at different instants relative to an irrigation operation; and

performing initial calibration measurements to derive a measured moisture value (FW1) before an initial irrigation operation and a measured moisture value (FW2) after the initial irrigation operation;

calculating an application specific characteristic K as follows;

2. The method as claimed in claim 1, further comprising measuring a field capacity moisture limit value GW_FK by completely saturating the soil with water, waiting for a waiting time sufficient for excess water to run off, and subsequently measuring the moisture value, wherein the measured moisture value corresponds to the field capacity moisture limit value GW_FK.

3. The method as claimed in claim 2, further comprising inputting a target upper moisture limit value GWmoist and generating an alarm report or replacing the target upper moisture limit value GWmoist by the field capacity moisture limit value GW_FK, if the target upper moisture limit value GWmoist lies above the field capacity moisture limit value GW_FK.

4. The method as claimed in claim 1, further comprising carrying out sequential irrigation operations, and for each sequential irrigation operation, measuring the soil moisture values before and after each irrigation operation, calculating the application specific characteristic K, and correcting the application specific characteristic K in the case of a deviation of the moisture value after an irrigation from a moisture limit value (GW).

5. The method as claimed in claim 1, further comprising calculating the irrigation duration for a subsequent irrigation operation with the aid of a characteristic K+y enlarged by an absolute value y or a characteristic K*y enlarged by a factor y>

1, if the moisture value after irrigation reaches a target upper moisture limit value GWmoist that corresponds to a predetermined maximum moisture of a soil, and thereby reducing the irrigation duration for the subsequent irrigation operation.

6. The method as claimed in claim 1, further comprising calculating the irrigation duration for a subsequent irrigation operation with the aid of a characteristic K-x reduced by an absolute value x or a characteristic K*x reduced by a factor x<

1, if the moisture value after irrigation does not reach a target upper moisture limit value GWmoist, and thereby increasing the irrigation duration for the subsequent irrigation operation.

7. The method as claimed in claim 1, wherein the calculated irrigation duration is enlarged or reduced by an absolute value D.

8. The method as claimed in claim 1, wherein a time between two irrigation cycles is reduced, if the measured moisture value falls below a lower moisture limit value GWdry between two irrigations, wherein GWdry corresponds to a predetermined minimum moisture of the soil.

15. The method as claimed in claim 1, further comprising inputting an initial value for application specific characteristic K.

9. An apparatus for irrigating plants having at least one sensor for measuring the soil moisture and an evaluation electronics, wherein the sensor is configured to repeatedly measure the soil moisture of the surrounding soil, and wherein the evaluation electronics is configured to store measurement parameters, wherein the apparatus is configured to be coordinated with an irrigation device in such a way that a soil moisture value (FW1) before and a soil moisture value (FW2) after an irrigation operation is measured, and the evaluation electronics is configured to calculate an irrigation duration for a following irrigation operation using an application specific characteristic K calculated as follows:

10. The apparatus as claimed in claim 9, further comprising an electronically actuable valve for opening and closing a water supply.

11. The apparatus as claimed in claim 9, wherein the irrigation duration is checked with the aid of the evaluation electronics by comparison of measured moisture values with a predetermined target upper moisture limit value and is regulated automatically by changing the application specific characteristic K such that the moisture value after irrigation reaches the target upper moisture limit value.

12. An electronic regulation for a soil moisture sensor, wherein the electronic regulation is configured for storing measured values of the moisture sensor for deriving therefrom a time profile of soil moisture, and for calculating an irrigation duration from a soil moisture value (FW1) before and a soil moisture value (FW2) after an irrigation operation, and wherein the electronic regulation is configured to calculate an irrigation duration for a subsequent irrigation operation using an application specific characteristic K calculated as follows:

13. The electronic regulation as claimed in claim 12, wherein the electronic regulation is configured to compare the calculated irrigation duration with a predetermined target upper moisture limit value, and, in the event of the latter being reached or exceeded, to adapt the irrigation duration by varying the application specific characteristic K.

14. The electronic regulation as claimed in claim 12 in combination with a soil moisture sensor.

16. A method for the regulation and control of an irrigation device, the method comprising:

performing initial calibration measurements to derive a measured moisture value (FW1) before an initial irrigation operation and a measured moisture value (FW2) after the initial irrigation operation;

calculating an application specific characteristic K as follows;

17. An apparatus for irrigating plants having at least one sensor for measuring the soil moisture and an evaluation electronics, wherein the sensor is configured to repeatedly measure the soil moisture of the surrounding soil, and wherein the evaluation electronics is configured to store measurement parameters including application specific characteristic K, calculated as follows:

18. An electronic regulation for a soil moisture sensor, wherein the electronic regulation is configured for storing measured values of the moisture sensor for deriving therefrom a time profile of soil moisture, and for calculating an irrigation duration from moisture values (FW) measured at different instants, and wherein the electronic regulation is configured to calculate an irrigation duration for subsequent irrigation operations using an application specific characteristic K calculated as follows:

19. A method for the regulation and control of an irrigation device, the method comprising:

providing an application specific characteristic K calculated as follows;

20. An apparatus for irrigating plants having at least one sensor for measuring the soil moisture and an evaluation electronics, wherein the sensor is configured to repeatedly measure the soil moisture of the surrounding soil, and wherein the evaluation electronics is configured to store measurement parameters including application specific characteristic K, calculated as follows:

21. An electronic regulation for a soil moisture sensor, wherein the electronic regulation is configured for storing measured values of the moisture sensor for deriving therefrom a time profile of soil moisture, and for calculating an irrigation duration from moisture values (FW) measured at different instants and for calculating an application specific characteristic K as follows: