Method and apparatus for irrigation control using evapotranspiration

• US 5,208,855 A
• Filed: 09/20/1991
• Issued: 05/04/1993
• Est. Priority Date: 09/20/1991
• Status: Expired due to Term

• Current Assignee: HydroPoint Data Systems Inc.
• Original Assignee: Michael B. Marian
• Inventors: Marian, Michael B.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/763,001
• Time in Patent Office: 592 Days
• Field of Search: 47/17, 239/69, 239/70, 380/9, 364/420
• US Class Current: 239/69
• 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: H04L 9/00 Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
• CPC Class Codes: Y02A 40/10 in agriculture
• CPC Class Codes: Y02A 40/22 Improving land use; Improving water use or availability; Controlling erosion

Abstract

The invention bypasses a need for human participation in the process of remotely controlling irrigation sprinklers using Evapotranspiration (ET) values. In one embodiment, a transmitter broadcasts updated Evapotranspiration (ET) data directly to a collection of receiver/controller units using an FM subcarrier. These receiver/controller units are microprocessor-based and coupled to a set of irrigation sprinklers.

The method provides for broadcasting an encoded ET data signal to a collection of receiving and irrigation-controlling units. The receiving and irrigation-controlling units include microprocessor means and storage means for storing a preset ET zone reference and crop adjustment values. The method also includes receiving and decrypting an encrypted ET data signal into a broadcast ET zone identifier and a broadcast corresponding ET value. The method further compares the broadcast ET zone identifier with the preset ET zone reference. The method adjusts an irrigation flow quantity responsive to the broadcast ET value, scaled by the crop adjustment value, when the broadcast ET zone identifier matches the preset ET zone reference.

Claims

1. A method of controlling irrigation, comprising the steps of:

locating a plurality of irrigation controllers, each for irrigation of a crop having an associated crop adjustment value, in a plurality of Evapotranspiration zones, each said irrigation controller including means for recording an Evapotranspiration zone reference and means for recording a crop adjustment value;

recording a particular one of said plurality of Evapotranspiration zones in said Evapotranspiration zone reference recording means of each irrigation controller within said particular Evapotranspiration zone;

recording said associated crop adjustment value in said crop adjustment recording means;

receiving a broadcast Evapotranspiration data signal at each of said plurality of irrigation controllers, said Evapotranspiration data signal including a plurality of Evapotranspiration zone identifiers and corresponding Evapotranspiration values;

comparing, at each irrigation controller, received Evapotranspiration zone identifiers with said Evapotranspiration zone reference stored in each particular controller until a particular one of said Evapotranspiration zone identifiers matches said Evapotranspiration zone reference to produce a match;

scaling, when a match is found, said Evapotranspiration value corresponding to said particular one Evapotranspiration zone identifier with said crop adjustment value recorded in said irrigation controller; and

adjusting an irrigation flow quantity to about equal said scaled Evapotranspiration value.

2. A method of controlling irrigation sprinklers using broadcast Evapotranspiration data, comprising the steps of:

broadcasting an Evapotranspiration data signal to a collection of receivers coupled to a plurality of irrigation flow controllers, said Evapotranspiration data signal containing a plurality of coded Evapotranspiration zone identifiers and corresponding coded Evapotranspiration values, each of said collection of receivers including means for storing an Evapotranspiration zone reference and a crop adjustment value;

receiving said Evapotranspiration data signal;

decoding said Evapotranspiration data signal to produce a plurality of decoded Evapotranspiration zone identifiers and corresponding Evapotranspiration values;

comparing each of said decoded Evapotranspiration zone identifiers with said Evapotranspiration zone reference; and

adjusting an irrigation flow quantity of particular ones of said plurality of flow controllers having said Evapotranspiration zone references matching a particular one of said decoded Evapotranspiration zone identifiers to about equal a product of a particular one of said Evapotranspiration values corresponding to said particular one decoded Evapotranspiration zone reference and said crop adjustment value.

3. The method of claim 2 wherein said broadcasting step comprises direct broadcasting from a geosynchronous communications satellite.

4. The method of claim 2 wherein said broadcasting step comprises direct broadcasting via FM subcarrier transmissions.

5. The method of claim 2 wherein said broadcasting step comprises direct broadcasting over a paging network.

6. The method of claim 2 wherein said broadcasting step includes encrypting Evapotranspiration broadcasts prior to broadcast and wherein said receiving step includes the step of decrypting said encoded information.

11. The system of claim 6 wherein said means for receiving said Evapotranspiration data signal and said means for adjusting irrigation flow responsive to said crop control code comprise an integral receiving and controlling unit.

12. The system of claim 6 wherein said means for broadcasting includes means for encrypting said Evapotranspiration data signal and wherein said means for receiving includes means for decrypting said encoded Evapotranspiration data signal.

7. A system for controlling irrigation sprinklers using broadcast Evapotranspiration data, comprising:

means for broadcasting an Evapotranspiration data signal to a collection of receivers coupled to irrigation flow controllers, said Evapotranspiration data signal containing broadcast coded Evapotranspiration zone identifiers and broadcast coded corresponding Evapotranspiration value, each of said collection of receivers including means for storing a Evapotranspiration zone reference and a crop adjustment value;

means for receiving said Evapotranspiration data signal;

means, coupled to said receiving means, for decoding said Evapotranspiration data signal to produce a plurality of decoded Evapotranspiration zone identifiers and corresponding Evapotranspiration values;

means, coupled to said decoding means, for comparing each of said decoded Evapotranspiration zone identifiers with said Evapotranspiration zone reference; and

means, coupled to said comparing means, for adjusting an irrigation flow quantity of said plurality of flow controllers having said Evapotranspiration zone references matching a particular one of said decoded Evapotranspiration zone identifiers to about equal a product of a particular one of said Evapotranspiration values corresponding to said particular one decoded Evapotranspiration zone reference and said crop adjustment value.

8. The system of claim 7 wherein said means for broadcasting comprises a geo-synchronous communications satellite capable of direct broadcast to earth-based receivers.

9. The system of claim 7 wherein said means for broadcasting comprises a means for broadcasting using FM subcarriers.

10. The system of claim 7 wherein said means for broadcasting comprises a means for broadcasting over a preexisting paging network.

13. A method of controlling irrigation sprinklers by receiving and processing FM subcarrier broadcasts of Evapotranspiration data to control automatically a set of irrigation sprinklers, said method comprising the steps of:

directly broadcasting an Evapotranspiration data signal from a transmitter;

receiving said Evapotranspiration data signal at a receiver;

coupling said Evapotranspiration data signal from said receiver to an irrigation flow controller having a preset duty cycle for watering; and

adjusting said preset duty cycle responsive to said Evapotranspiration data signal to provide an adjusted duty-cycle signal.

14. A system for regulating sprinkler controllers using direct broadcast of Evapotranspiration data, said system comprising:

means for directly broadcasting an Evapotranspiration data signal;

receiving means for receiving said Evapotranspiration data signal;

an irrigation sprinkler controller having a preset duty cycle for watering;

means for coupling said Evapotranspiration data signal from said receiving means to said irrigation sprinkler controller;

means for adjusting in said irrigation sprinkler controller said preset duty cycle for watering responsive to said Evapotranspiration data signal to provide an adjusted duty-cycle signal, whereby said irrigation sprinkler controls the amount of water sent to plants according to said adjusted duty-cycle signal.

15. A system for directly broadcasting selected portions of an Evapotranspiration database to a collection of receiving and sprinkler-controlling units distributed over a geographic area, each receiving and sprinkler-controlling unit being coupled to at least one irrigation sprinkler, said system comprising:

means for directly broadcasting a stream of encrypted Evapotranspiration data;

a plurality of irrigation sprinkler controllers, each of said controllers having a preset duty cycle for watering;

a plurality of receiving means for receiving said encoded Evapotranspiration data signal, each of said receiving means being coupled to at least one of said irrigation sprinkler controllers, and each receiving means including means for storing a preset Evapotranspiration zone reference and for storing a preset crop adjustment value;

each of said receiving means also including means for decrypting said encrypted irrigation control signal into a broadcast Evapotranspiration zone identifier and a broadcast corresponding Evapotranspiration value;

each of said receiving means coupled to irrigation sprinkler controller means including means of comparing said broadcast Evapotranspiration zone identifier with said preset Evapotranspiration zone reference such that each of said sprinkler controllers is selectively responsive to a corresponding one of said Evapotranspiration values of one of said zone identifiers;

means for coupling said Evapotranspiration data signal from each of said receiving means to said irrigation sprinkler controllers;

means for adjusting in said irrigation sprinkler controllers said preset duty cycles for watering responsive to said Evapotranspiration data signals and also responsive to said preset crop adjustment value to provide adjusted duty-cycle signals, whereby said each of said irrigation sprinkler controllers controls the amount of water sent to plants according to said adjusted duty-cycle signal.

16. A method of distributing Evapotranspiration information for a plurality of Evapotranspiration zones over a distributed geographic area for automatic adjustment of watering intervals for irrigation flow controllers, comprising the steps of:

compiling a database of a plurality of Evapotranspiration values for each of the plurality of Evapotranspiration zones;

matching each of said plurality of Evapotranspiration values with its corresponding Evapotranspiration zone to produce a set of Evapotranspiration zones having corresponding Evapotranspiration values; and

broadcasting periodically said set of Evapotranspiration zones with corresponding Evapotranspiration values.