METHOD AND APPARATUS FOR THE AUTOMATIC REGULATION OF THE IRRIGATION OF PLANTS

• US 20110238226A1
• Filed: 08/19/2009
• Published: 09/29/2011
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: PlantCare AG
• Original Assignee: PlantCare AG
• Inventors: Toprak, Yucel, Schmidt, Walter
• Granted Patent: US 8,862,276 B2
• Time in Patent Office: Days
• 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

1-16. -16. (canceled)

17. A method for the regulation and control of an irrigation device comprising a sensor for measuring the soil moisture and an evaluation electronics, comprising the following steps:

repeatedly measuring the soil moisture and deriving a moisture value (FW1) before an irrigation and a moisture value (FW2) after an irrigation;

analyzing a time profile of the soil moisture before and after an irrigation operation; and

calculating an irrigation time (BD) from the moisture value (FW1) before an irrigation and the moisture value (FW2) after an irrigation.

18. The method as claimed in claim 17, further comprising the step of performing an initial calibration measurement to derive from the measured moisture value (FW1) before an irrigation and the moisture value (FW2) after an irrigation an application specific characteristic K, and using the characteristic K to calculate the irrigation time (BD) of the following irrigation operations.

19. The method as claimed in claim 18, in which the characteristic K is calculated as follows

20. The method as claimed in claim 17, further comprising a step of measuring a field capacity moisture limit value GW_FK by selecting an irrigation time to be so long that a soil is completely saturated with water, waiting for a sufficiently long waiting time, and subsequently measuring the moisture value, wherein the measured moisture value corresponds to the field capacity moisture limit value GW_FK.

21. The method as claimed in claim 20, further comprising the step of inputting a moisture limit value GWmoist and generating an alarm report or replacing the moisture limit value GWmoist by the field capacity moisture limit value GW_FK, if the moisture limit value GWmoist lies above the field capacity moisture limit value GW_FK.

22. The method as claimed in claim 18, further comprising the step of carrying out irrigations cyclically, measuring the moisture values before and after irrigation, calculating the characteristic K, and correcting the characteristic K in the case of a deviation of the moisture value after an irrigation from a moisture limit value (GW).

23. The method as claimed in claim 22, further comprising the step of calculating the irrigation time (BD) for the following irrigation with the aid of a characteristic K+y enlarged by an absolute value y, if the moisture value after irrigation reaches an upper moisture limit value GWmoist that corresponds to a predetermined maximum moisture of a soil, and thereby reducing the irrigation time for the following irrigation.

24. The method as claimed in claim 22, further comprising the step of calculating the irrigation time (BD) for the following irrigation with the aid of a characteristic K-x reduced by an absolute value x, if the moisture value after irrigation does not reach the upper moisture limit value GWmoist, and thereby increasing the irrigation time for the following irrigation.

25. The method as claimed in claim 17, wherein a calculated irrigation time (BD) is enlarged or reduced by an absolute value D.

26. The method as claimed in claim 17, 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 a soil.

30. An electronic regulation for a moisture sensor for use in the method as claimed in claim 17, wherein measured values of a moisture sensor are stored, a time profile of a soil moisture is derived therefrom, and an irrigation time (BD) is calculated from moisture values (FW) at different instants.

31. The electronic regulation as claimed in claim 30, in which the calculated irrigation time (BD) is compared with a predetermined moisture limit value (FW), and, in the event of the latter being reached or exceeded, the irrigation time is adapted by variation of a previously determined characteristic K.

32. The use of the electronic regulation as claimed in claim 30 in a soil moisture sensor.

27. An apparatus for irrigating plants having at least one sensor for measuring the soil moisture and an evaluation electronics, wherein the sensor can be used to repeatedly measure the soil moisture of the surrounding soil and measurement parameters can be stored with the aid of the evaluation electronics, wherein the apparatus is able to be coordinated with an irrigation device in such a way that a time profile of the soil moisture before and after an irrigation operation is measured and analyzed, and an irrigation time (BD) can be calculated from a moisture value (FW1) before an irrigation and a moisture value (FW2) after an irrigation.

28. The apparatus as claimed in claim 27, further comprising an electronically actuable valve for opening and closing a water supply.

29. The apparatus as claimed in claim 27, in which an application specific characteristic K can be determined in order to calculate the irrigation time (BD) which irrigation time can be checked with the aid of the evaluation electronics by comparison of measured moisture values with a predetermined moisture limit value (GW) and can be regulated automatically by changing the characteristic K such that the moisture value after irrigation reaches the moisture limit value.