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

• US 20140379149A1
• Filed: 08/27/2014
• Published: 12/25/2014
• Est. Priority Date: 09/05/2008
• Status: Active Grant

• Current Assignee: PlantCare AG
• Original Assignee: PlantCare AG
• Inventors: Schmidt, Walter, Toprak, Yucel
• Granted Patent: US 9,775,308 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

The invention relates to 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 automatically controlling an irrigation duration, the method comprising

calculating an irrigation duration by the aid of evaluation electronics and an application specific characteristic K;

obtaining a soil moisture value by measuring soil moisture using a sensor after a soil irrigation operation for the calculated irrigation duration has been conducted;

comparing the obtained soil moisture value with a target upper moisture limit value using the evaluation electronics and, in the event that the obtained soil moisture value deviates from the target upper moisture limit value, applying a correction to the application specific characteristic K to thereby alter an irrigation duration for a subsequent soil irrigation operation.

2. The method according to claim 1, comprising

obtaining a further soil moisture value by measuring soil moisture using the sensor before the subsequent soil irrigation operation is carried out;

and

carrying out the subsequent soil irrigation operation only if the obtained further soil moisture value is lower than a dry limit value.

3. The method according to claim 2, comprising inputting into the evaluation electronics the target upper moisture limit value and the dry limit value, wherein the target upper moisture limit value and the dry limit value are user-selected values.

4. The method according to claim 1, wherein the applying the correction to the application specific characteristic K is accomplished

by enlarging K to K+y with an absolute value y or to k*y with a factor y>

1, in the event that the obtained soil moisture value reaches the target upper moisture limit value, thereby reducing the irrigation duration for the subsequent soil irrigation operation; and

by reducing K to K−

x with an absolute value x or to k*x with a factor x<

1, in the event that the obtained soil moisture value does not reach the target upper moisture limit value, thereby increasing the irrigation duration for the subsequent soil irrigation operation.

5. The method according to claim 1, wherein an initial calibration measurement is conducted in which an initial application specific characteristic K used for calculating an irrigation duration for a next soil irrigation operation conducted after an initial soil irrigation operation is derived from a moisture value measured before the initial soil irrigation operation and a moisture value measured after the initial soil irrigation operation.

6. The method according to claim 1, comprising inputting into the evaluation electronics a user-selected initial application specific characteristic K used for calculating an irrigation duration for a soil irrigation operation.

7. The method according to claim 1, wherein the application specific characteristic K indicates by how much soil moisture changes when watering is performed for a specific duration and with a specific amount of water.

8. An apparatus for automatically controlling plant irrigation operations using an associated irrigation device, the apparatus comprising

at least one sensor configured to repeatedly measure soil moisture of soil irrigated by the irrigation device;

and

an evaluation electronics configured to calculate an irrigation duration using an application specific characteristic K;

wherein the apparatus is configured to alter the irrigation duration of a subsequent irrigation operation by the aid of the evaluation electronics by applying a correction to a previous application specific characteristic K, if a soil moisture value obtained by the at least one sensor after an irrigation operation conducted for an irrigation duration calculated using the previous application specific characteristic K deviates from a target upper moisture value.

9. An electronic controller for plant irrigation configured to be coordinated with a sensor for measuring soil moisture and with an irrigation device, the electronic controller comprising an evaluation electronics configured to calculate an irrigation duration with the aid of an application specific characteristic K, wherein the electronic controller is configured to alter the irrigation duration of a subsequent irrigation operation by the aid of the evaluation electronics by applying a correction to a previous application specific characteristic K, if a soil moisture value obtained by the sensor after an irrigation operation conducted for an irrigation duration calculated using the previous application specific characteristic K deviates from a target upper moisture value.

10. A method for automatic control of an irrigation duration, the method comprising

calculating an irrigation duration using an application specific characteristic K;

measuring soil moisture using a sensor after a soil irrigation operation for the calculated irrigation duration has been accomplished to obtain a measured soil moisture value;

comparing, by the aid of evaluation electronics, the measured soil moisture value with a predetermined target upper moisture limit value; and

automatically controlling an irrigation duration for a subsequent soil irrigation operation by applying an adjustment to the application specific characteristic K by the aid of which the irrigation duration for the subsequent soil irrigation operation is calculated, wherein said adjustment to the application specific characteristic K is calculated to effect that a subsequent soil moisture value measured by the aid of the sensor after the subsequent soil irrigation operation is closer to the predetermined target upper moisture limit value than the measured soil moisture value.

11. An apparatus for automatically controlling plant irrigation operations using an associated irrigation device, the apparatus comprising

at least one sensor configured to repeatedly measure soil moisture of soil irrigated by the irrigation device;

and

an evaluation electronics configured to calculate an irrigation duration using an application specific characteristic K;

wherein the apparatus is configured to automatically control an irrigation duration of a subsequent soil irrigation operation by the aid of the evaluation electronics by comparing a target upper moisture value and a measured soil moisture value obtained by the at least one sensor after an irrigation operation has been conducted for an irrigation duration calculated using the application specific characteristic K, and by applying an adjustment to the application specific characteristic K to effect that a subsequent soil moisture value measured by the aid of the at least one sensor after the subsequent soil irrigation operation is closer to the predetermined target upper moisture limit value than the measured soil moisture value.

12. An electronic controller for plant irrigation configured to be coordinated with a sensor for measuring soil moisture and with an irrigation device, the electronic controller comprising an evaluation electronics configured to calculate an irrigation duration with the aid of an application specific characteristic K, wherein the electronic controller is configured to automatically control an irrigation duration of a subsequent soil irrigation operation by the aid of the evaluation electronics by comparing a target upper moisture value and a measured soil moisture value obtained by the sensor after an irrigation operation has been conducted for an irrigation duration calculated using the application specific characteristic K, and by applying an adjustment to the application specific characteristic K to effect that a subsequent soil moisture value measured by the aid of the sensor after the subsequent soil irrigation operation is closer to the predetermined target upper moisture limit value than the measured soil moisture value.

13. A method for automatically controlling an irrigation duration, the method comprising repeatedly conducting the following sequence of automatically conducted steps:

obtaining a soil moisture value FW2 by measuring soil moisture using a sensor after a soil irrigation operation has been conducted;

applying a correction to an application specific characteristic K, the correction depending on a deviation of the obtained soil moisture value FW2 from a predetermined target upper moisture limit value;

calculating an irrigation duration for a following irrigation operation by the aid of the corrected application specific characteristic K and in dependence of a soil moisture value FW1 obtained by measuring soil moisture using the sensor before the following soil irrigation operation.

14. An apparatus for automatically controlling plant irrigation operations using an associated irrigation device, the apparatus comprising

at least one sensor configured to repeatedly measure soil moisture of soil irrigated by the irrigation device;

and

an evaluation electronics configured to calculate an irrigation duration using an application specific characteristic K;

wherein the apparatus is configured to repeatedly automatically conduct the following sequence of steps;

obtaining a soil moisture value FW2 by measuring soil moisture using the sensor after a soil irrigation operation has been conducted;

applying a correction to the application specific characteristic K by the aid of the evaluation electronics, the correction depending on a deviation of the obtained soil moisture value FW2 from a predetermined target upper moisture limit value;

calculating, by the aid of the evaluation electronics, an irrigation duration for a following irrigation operation by the aid of the corrected application specific characteristic K and in dependence of a soil moisture value FW1 obtained by measuring soil moisture using the sensor before the following soil irrigation operation.

15. An electronic controller for plant irrigation configured to be coordinated with a sensor for measuring soil moisture and with an irrigation device, the electronic controller comprising an evaluation electronics configured to calculate an irrigation duration with the aid of an application specific characteristic K, wherein the electronic controller is configured to repeatedly automatically conduct the following sequence of steps:

receiving from the sensor a soil moisture value FW2 obtained by the sensor by measuring soil moisture after a soil irrigation operation has been conducted;

applying a correction to the application specific characteristic K by the aid of the evaluation electronics, the correction depending on a deviation of the received soil moisture value FW2 from a predetermined target upper moisture limit value;

calculating, by the aid of the evaluation electronics, an irrigation duration for a following irrigation operation by the aid of the corrected application specific characteristic K and in dependence of a soil moisture value FW1 received from the sensor obtained by the sensor by measuring soil moisture before the following soil irrigation operation.