WO2003085473A1

WO2003085473A1 - Irrigation 'watering reduction value'

Info

Publication number: WO2003085473A1
Application number: PCT/US2002/010429
Authority: WO
Inventors: John Addink; Kirk Buhler
Original assignee: Aqua Conservation Systems, Inc.
Priority date: 2002-04-03
Filing date: 2002-04-03
Publication date: 2003-10-16
Also published as: AU2002256051A1

Abstract

The present invention provides systems and methods in which an irrigation controller combines a global scheduling change feature, with automatic seasonal adjustment changes (Figure 2, 200, 270, 310, 350, 360). The global scheduling change feature comprises a 'watering reduction value'. Preferably the automatic seasonal adjustment is at least partly derived from ET data. Additionally, the irrigation schedule can also be derived, at least in part, from a crop coefficient value, an irrigation efficiency value and/or rainfall data. Preferably the 'watering reduction value' is set during manufacture or distribution and at a value of 80%.

Description

IRRIGATION 'WATERING REDUCTION VALUE'

Field of the Invention

The field of the invention is irrigation controllers.

Background of the Invention In arid areas of the world water is becoming one of the most precious natural resources. Meeting future water needs in these arid areas may require aggressive conservation measures. This requires irrigation systems that apply water to the landscape based on the water requirements of the plants. Many irrigation controllers have been developed for automatically controlling application of water to landscapes. Known irrigation controllers range from simple devices that control watering times based upon fixed schedules, to sophisticated devices that vary the watering schedules according to local geographic and climatic conditions.

With respect to the simpler types of irrigation controllers, a homeowner typically sets a watering schedule that involves specific run-times and days for each of a plurality of stations, and the controller executes the same schedule regardless of the season or weather conditions. Such systems are flexible, but inherently inconvenient. For example, watering schedule changes required to accommodate differing seasonal needs force homeowners to manually adjust the watering schedule by changing of the run-times for each individual station.

More recent irrigation controllers include a global scheduling change feature, frequently termed a 'water budget percent', that can be used to reduce the run-times of all the stations by entering a change in only one control setting. The reduction in run-time settings with a change in one control setting is discussed in U.S. Patent No. 4,176,395 issued November, 1979, to Evelyn-Neere, U.S. Patent No. 5,251,153 issued October, 1993, to Nielsen, et al., U.S. Patent No. 5,444,611 issued August, 1995 to Woytowitz, and U.S. Patent No. 5,748,466 issued May, 1998 to McGivern, et al. In such systems the default setting is usually 100% and then during the year the percent can be increased or decreased based on the increased or decreased requirement for water, respectively.

Unfortunately, many geographical regions need monthly or even daily changes to the watering schedule to optimally accommodate seasonal watering needs. It is just not reasonable to expect homeowners to make such frequent changes in the watering schedule. Typical homeowners make one change in the late Spring when a portion of the yard becomes brown due to a lack of water, and another change in the late Fall when the homeowner assumes that the vegetation does not require as much watering. Sometimes there are changes made during the summer to increase the run-times of all stations due to the high requirements of water during the summer. But these changes to the watering schedule are typically insufficient to achieve efficient watering.

More sophisticated irrigation controllers use evapotranspiration rates for determining the amount of water to be applied to a landscape. Evapotranspiration is the water lost by direct evaporation from the soil and plant and by transpiration from the plant surface.

Potential evapotranspiration (ETo) is calculated from meteorological data. ETo calculations are closely correlated to the water requirements of plants. Irrigation controllers that derive all or part of their irrigation schedule from potential ETo data are discussed in US Patent No. 5,479,339 issued December 1995, to Miller, US Patent No. 5,097,861 issued March 1992 to Hopkins, et al., US Patent No. 5,023,787 issued June 1991and US Patent No. 5,229,937 issued July 1993 both to Evelyn-Veere. US Patent No. 5,208,855, issued May,1993, to Marian, US Patent No. 5,696,671, issued December 1997, and US Patent No. 5,870,302, issued February 1999, both to Oliver and US Patent No. 6,102,061, issued August, 2000 to Addink.

None of the above ETo patents describes the use of a single control feature to reduce the run-times of the irrigation stations. Presumably this omission was due to a failure to appreciate a need for such a control feature since the ETo feature automatically reduces the run-times of the irrigation stations in the spring and fall when there is less evapotranspiration. Generally, most ETo based irrigation controllers have the run-time settings initially set for the peak water requirements of the plants or the run-time setting that would be used for summer irrigations. As the weather turns cooler, from summer to fall, the ETo value decreases and the run-times are automatically reduced.

Even with ETo controllers there is a problem with user's failing to enter adjustments with sufficient frequency. What happens in actual practice with known ETo based irrigation controllers is that the consumers enter initial pealc summer run-time minutes that are above the water requirements of the plants. A few consumers may experiment and back off the peak summer run time minutes to determine what the minimum setting should be to provide the water required for good plant growth, but most won't do that.

Surprisingly, no one seems to have appreciated the need for a controller that combines a global scheduling change feature, (such as a 'watering reduction value'), with automatic seasonal adjustment changes, (such as that derived from ETo data).

Summary of the Invention

The present invention provides systems and methods in which an irrigation controller combines a global scheduling change feature with automatic seasonal adjustment changes.

In preferred embodiments the global scheduling change feature comprises a 'watering reduction value' adjustment, hi such systems the 'watering reduction value' is advantageously set during manufacturing or distribution at a desired value, such as 80%. The 'watering reduction value' can take any form, including a numeric value, alphabetic value, or other appropriate value.

Automatic seasonal adjustment is preferably based at least partly on evapotranspiration (ET) data, which can be received locally at or near the controller, or received from a distal source. Automatic seasonal adjustment can additionally be based upon other suitable information, including a crop coefficient value, an irrigation efficiency value, and/or rainfall data.

Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description that describes a preferred embodiment of the invention, along with the accompanying drawings in which like numerals represent like components.

Brief Description of the Drawings

Figure 1 is a schematic of an irrigation controller according to an aspect of the present invention.

Figure 2 is a block diagram of an irrigation system according to an aspect of the present invention. Figure 3 is a graphical representation of a yearly irrigation application by an irrigation controller according to an aspect of the present invention.

Figure 4 is a graphical representation of yearly irrigation applications by prior art irrigation controllers.

Figure 5 is a graphical representation of yearly irrigation applications of prior art irrigation controllers compared to a yearly irrigation application of an irrigation controller according to an aspect of the present invention.

Detailed Description

Figure 1 is a schematic of an irrigation controller 200 according to the present invention that generally includes a microprocessor 220, an on-board memory 210, watering reduction control device 230, some manual input devices 231 and 232 (buttons and/or knobs), an input/output (I/O) circuitry 221 connected in a conventional manner, a display screen 250, a communications port 240, a serial, parallel or other communications connection 241 coupling the irrigation controller to one or more communication sources, electrical connectors 260 which are coimected to a plurality of irrigation stations 270 and a power supply 280, a rain detection device 291, a flow sensor 292, a pressure sensor 293 and a temperature sensor 294. Each of these components by itself is well known in the electronic industry, with the exception of the programming of the microprocessor in accordance with the functionality set forth herein. There are hundreds of suitable chips that can be used for this purpose. At present, experimental versions have been made using a generic Intel 80C54 chip, and it is contemplated that such a chip would be satisfactory for production models.

In a preferred embodiment, the controller has one or more common communication internal bus(es). The bus can use a common or custom protocol to communicate between devices. There are several suitable communication protocols, which can be used for this purpose. At present, experimental versions have been made using an I²C serial data communication, and it is contemplated that this communication method would be satisfactory for production models. This bus is used for internal data transfer to and from the EEPROM memory, and is used for communication with personal computers, peripheral devices, and measurement equipment including but not limited to utility meters, water pressure sensors, and temperature sensors. Contemplated irrigation controllers can be used to control a residential irrigation system, an agricultural irrigation system, horticultural irrigation system or any other type of irrigation system.

In Figure 2 a single irrigation controller 200 operates two irrigation stations 270. It will be understood that these stations 270 are indicative of any two or more irrigation stations, and are not to be interpreted as limiting the number or configuration of irrigation stations. It is contemplated that the irrigation stations can be part of an underground installed irrigation system, such as those used on residential sites, commercial sites, golf courses, public parks, and so forth. Alternatively, the irrigation stations can be part of center pivot systems, wheel type systems, solid set systems, or any other type of irrigation system used in the irrigating of plants. Among other things, the irrigation controller 200 operates solenoids (not shown) that open the station valves 350 to allow irrigation water from the water source 310 to be distributed to the various irrigation stations 270 and thereby irrigate the landscape through one or more (four are shown for each irrigation station but it can be any number) irrigation sprinkler heads 360.

Although numerous other data points could be employed to begin operations, it is considered particularly convenient for an irrigation user to enter peak summer run minutes as a baseline run value, when the irrigation controller is initially installed. For example, if the irrigated site is a lawn the irrigation user might enter in the irrigation controller 10 minute run-times for the initial irrigation setting, and with a watering frequency of seven days a week. Additionally, in a preferred embodiment of the present invention a 'watering reduction value' would be preset in the irrigation controller. Preferably the 'watering reduction value' would be preset by the manufacturer or distributor to a value of, perhaps 80%), or some other value such as that between 80% and 100%). However, it can be appreciated that the percent can be set at a number less than 80%> or more than 100%. It should also be appreciated that the 'watering reduction value' can be a value other than a percent value, such as a numeric value, alphabetic value, or other appropriate value.

The 'watering reduction value' preferably provides for an increase or decrease in the run-times of all the stations. Therefore, with a 'watering reduction value' of 80%, the run- times for the above example would be 8 minutes (which is 80%_> of 10 minutes) for all the stations, since all the stations were set at a 10 minute summer run-time setting. In practice, however, it is very likely that some stations will have different run-times from other stations. In such cases the 'watering reduction value' (whether 80% or some other value) that is preset at the factory will automatically reduce all of the station run-times by that value, regardless what the summer run-time settings are for each station.

Numerous examples of water savings will be appreciated by those skilled in the art.

For example, it is widely accepted that homeowners and even commercial or government irrigation users frequently over-water their lawns. Therefore, the peak summer minutes the irrigation user enters in the irrigation controller will almost always be higher than is normally required by the plants during the summer. By presetting the 'watering reduction value' to a value less than 100% at the factory, it is more likely the water applied to the irrigation user's landscape will more closely meet the plant's water requirements without wasting water. Should the landscape plants show any drought symptoms the irrigation user can increase the 'watering reduction value' with the watering reduction control device 230.

The automatic seasonal adjustment changes are also readily comprehended. During the year, the irrigation controller automatically modifies the cycle amounts based upon estimated variances in watering needs. A typical example provides the average cycle amounts depicted in Figure 3, Irrigation Application A. Here again, manual changes can be made from time to time to fine-tune the irrigation schedule, which would alter the height or shape of the curve.

In the example, Irrigation Application A is partly derived from an ET value. The ET value can be a simple number received or installed from an outside source, or it can be calculated from weather data . from such as temperature, humidity, solar radiation, and wind.

Where the ET value is received from a source distal to the irrigated site, it is preferred that the value is carried over the Internet or other network through the communications port 240 . However, the ET value or weather data used in calculating the ET value can alternatively or additionally be received via a telephone line, radio, pager, two-way pager, cable, and any other suitable communication mechanism. It is also contemplated that the microprocessor 220, (see Figure 1) can receive the weather data used in calculating the ET value directly from local sensors, such as the temperature sensor 294 , located at the irrigation site. Since weather can change very rapidly, it is preferred that the ET value, or data used in calculating the ET value, is current within the previous two weeks, preferably within the most recent few days, and even more preferably from the current day. Furthermore, ET values can be "potential" ET values (ETo) received by the microprocessor 220 or estimated ET values derived from weather data received by the microprocessor 220. The ET value can also be a historic ET value that is stored in the memory 210 of the irrigation controller 200.

It is contemplated that additional information can be used by the irrigation controller to derive Irrigation Application A, and in particular can include one or all of the following: rainfall data, crop coefficient values, irrigation efficiency values and so forth.

Figure 4 is a graphical representation of yearly irrigation applications by prior art irrigation controllers. In that figure irrigation Application B exemplifies the yearly ' applications of a manual irrigation controller with a 'water budget' feature. The irrigation user will usually set the summer run-time minutes in a manual irrigation controller with a 'water budget' feature. Using the information from the above example the summer run-time minutes would be set at 10 minutes. In this example, however, the 'water budget' is factory set at a default value of 100%). Therefore, the full 10 minutes of run-time would occur with each station during the summer. Then in the fall and spring the irrigation user changes the 'water budget' so less water would be applied to the landscape. During the early spring the irrigation user might set the 'water budget' at 50% and then change it to 75% later in the spring. By early summer the irrigation user will likely set the 'water budget' back to the default value of 100%. Other than the first early spring setting, each of the later settings were probably made by the irrigation user because he/she observed some plant drought stress and decided that he/she should increase the watering amount, hi the fall, the irrigation user may remember to lower the 'water budget' as it becomes cooler and the water requirements of the plants decrease. However, not all irrigation users will lower the 'water budget' if the landscape plants appear in a healthy condition. They may decide to leave the 'water budget' setting alone. With Irrigation Application B, Figure 3 the assumption was made that the irrigation user would have lowered the 'water budget' at least one time during the late summer or fall period.

Irrigation Application C exemplifies the yearly applications of an ET irrigation controller without a 'watering reduction value' feature. The shape of the curve of Irrigation Application C is very similar to the shape of the curve of Irrigation Application A, Figure 3. However, the peak summer run-time minutes are 20%) higher for Irrigation Application C compared to the peak summer run-time minutes for Irrigation Application A, Figure 5. Because the 'watering reduction value' is set at the factory at 80%>, Irrigation Application A will apply 20% less water to the landscape than Irrigation Application C. This is based on the assumption that no changes were made to the irrigation controller settings and both controllers were initially set at 10 minutes for the peak summer run-time minutes.

With a prior art ET irrigation controller, an irrigation user could manually lower the run-time minutes for each of the irrigation stations, but it is not very likely they will do that unless they are required to by some governmental agency, or there is so much excessive use of water that mushrooms grow, or some other sequela of over watering becomes apparent to the user. One reason is that irrigation applications usually occur in the early morning hours, and the irrigation user may not realize the amount of water they are wasting during an irrigation application. The landscape plants look good, so why should they take the time to change the run-time minutes of each irrigation station? However, an ET irrigation controller, according to the present invention, with a 'watering reduction value' feature, will automatically be applying 20% less than the entered summer run-time minutes. If the plant material should show any signs of drought stress the irrigation user will likely set the 'watering reduction value' higher to apply more water. However, since as mentioned earlier, many irrigation users have their irrigation controllers set to over water their landscape, the plants might never show any drought stress even with the 80% 'watering reduction value' setting. Therefore the irrigation user would typically not change the percentage of the 'watering reduction value'.

As is demonstrated by the Irrigation Applications in Figure 5, the ET irrigation controller with a 'watering reduction value' feature (Irrigation Application A) will generally conserve more water than a prior art ET irrigation controller with no 'watering reduction value' feature (Irrigation Application C), or a prior art manual irrigation controller with a 'water budget' feature (Irrigation Application B).

Many irrigation controllers have two or more program features that can be used to apply different irrigation schedules to different areas of the landscape. For example, assume a drip irrigation system is used to water the planting beds, containing small shrubs and a sprinkler irrigation system is used to water the lawn. All the stations that apply irrigation water to the beds are on Program A and all the stations that apply irrigation water to the lawn are on Program B. Program A can also have an irrigation schedule that involves every day irrigation applications whereas Program B might have an irrigation schedule that involves every other day irrigation applications. Preferably the 'watering reduction value' control feature will have a global affect on all stations or will modify the run-time settings of the stations of Program A and the stations of Program B by the same percentage. Alternatively or additionally, the 'watering reduction value' control feature could be set to modify the irrigation schedule of Program A by a certain percentage and modify the irrigation schedule of Program B by a different percentage. Nevertheless, it is also contemplated that there will be means in the irrigation controller to set a global 'watering reduction value' and also a means to set a 'watering reduction value' for each program independently.

The 'watering reduction value' can be stored in any suitable location, such as a nonvolatile memory 210 of the irrigation controller. Should the irrigation controller ever lose power or inadvertently be turned off preferably the default 80%> 'water reduction value' will be stored in the memory.

Thus, specific embodiments and applications of methods and apparatus of the present invention have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims.

Claims

CLAIMSWhat is claimed is:

1. An irrigation controller that combines a global scheduling change feature, with automatic seasonal adjustment changes.

2. The irrigation controller of claim 1, wherein the global scheduling change feature comprises a 'watering reduction value'.

3. The irrigation controller of claim 1, wherein the automatic seasonal adjustment is at least partly derived from evapotranspiration (ET) data.

4. The irrigation controller of claim 1, wherein the automatic seasonal adjustment is at least partly derived from a crop coefficient value.

5. The irrigation controller of claim 1, wherein the automatic seasonal adjustment is at least partly derived from an irrigation efficiency value.

6. The irrigation controller of claim 2, wherein the 'watering reduction value' is set during manufacture or distribution.

7. The irrigation controller of claim 6, wherein the 'watering reduction value' is set to a percent other than 100%>.

8. The irrigation controller of claim 2, wherein the 'watering reduction value' is a value other than a percent value.

9 An irrigation controller comprising:

(a) an ET based irrigation schedule;

(b) a global 'watering reduction value' ;

(c) a means for setting the global 'watering reduction value'; and

(d) a means for storing the global 'watering reduction value' .