Irrigation system with et based seasonal watering adjustment

Abstract

An ET based irrigation system includes a stand alone irrigation controller with a seasonal adjust feature and a stand alone weather station including at least one environmental sensor. The ET based irrigation system further includes a stand alone ET unit operatively connected to the irrigation controller and the weather station. The ET unit includes programming configured to calculate an estimated ET value using a signal from the environmental sensor and to automatically modify a watering schedule of the irrigation controller through the seasonal adjust feature based on the estimated ET value to thereby conserve water while maintaining plant health.

What is claimed is: 
     
         1 . An irrigation system comprising:
 a stand alone irrigation controller comprising a first plurality of user inputs that enable a user to enter a watering schedule including a run time and to manually adjust a percentage adjustment value of a percentage adjustment feature, a computer processor operatively connected to the plurality of user inputs, and a memory connected to the computer processor, wherein programming stored in the memory implements said percentage adjustment feature to change the run time of the watering schedule by the percentage adjustment value;   a stand alone weather station including at least one environmental sensor; and   a stand alone control unit comprising a memory storing programming that calculates an irrigation value using a signal from the at least one environmental sensor and communicates an irrigation adjustment value responsive to the irrigation value to the computer processor of the stand alone irrigation controller to automatically modify said percentage adjustment value.   
     
     
         2 . The irrigation system of  claim 1  wherein the at least one environmental sensor comprises a solar radiation sensor configured to detect solar radiation and a temperature sensor configured to detect temperature. 
     
     
         3 . The irrigation system of  claim 2  wherein the irrigation value is calculated based at least in part on the solar radiation, the temperature, and at least one constant. 
     
     
         4 . The irrigation system of  claim 3  wherein the at least one constant is selected to simulate local environmental conditions of the irrigation site. 
     
     
         5 . The irrigation system of  claim 1  wherein the stand alone weather station further comprises a rain sensor configured to detect a rain event. 
     
     
         6 . The irrigation system of  claim 5  wherein the stand alone control unit communicates an automatic irrigation shut down to the computer processor of the stand alone irrigation controller based at least in part on the rain event. 
     
     
         7 . The irrigation system of  claim 3  wherein the temperature sensor is further configured to detect a freeze condition and the stand alone control unit communicates an automatic irrigation shut down to the computer processor of the stand alone irrigation controller based at least in part on the freeze condition. 
     
     
         8 . The irrigation system of  claim 1  wherein the irrigation value is calculated based at least in part on the signal from the at least one environmental sensor and a reference point. 
     
     
         9 . The irrigation system of  claim 8  wherein the reference point comprises a maximum expected irrigation setting calculated based on constants selected to simulate local conditions of an irrigation site. 
     
     
         10 . The irrigation system of  claim 9  wherein the stand alone control unit further comprises a second plurality of user inputs that enable the user to change the reference point. 
     
     
         11 . An irrigation system comprising:
 a plurality of user inputs that enable a user to enter a watering schedule including a run time and to manually adjust a percentage adjustment value of a percentage adjustment feature;   a computer processor operatively connected to the plurality of user inputs;   a memory connected to the computer processor to store the watering schedule;   at least one environmental sensor configured to generate a signal representative of an environmental condition, the computer processor configured to calculate an irrigation value based at least in part on the signal from the at least one environmental sensor and determine an irrigation adjustment value responsive to the irrigation value; and   programming stored in the memory to implement said percentage adjustment feature to increase or decrease the run time of the watering schedule by the percentage adjustment value, the programming automatically increasing or decreasing said percentage adjustment value based on the irrigation adjustment value.   
     
     
         12 . The irrigation system of  claim 11  wherein the signal from the at least one environmental sensor comprises at least one of temperature, humidity, solar radiation, wind, and rain. 
     
     
         13 . The irrigation system of  claim 12  wherein the irrigation value is calculated based at least in part on the signal from the at least one environmental sensor and one or more constants representative of a geographical region associated with an irrigation site. 
     
     
         14 . The irrigation system of  claim 11  wherein the percentage adjustment value comprises a scaling factor. 
     
     
         15 . The irrigation system of  claim 11  wherein the at least one environmental sensor is located at an irrigation site. 
     
     
         16 . A method of controlling a plurality of valves on an irrigation site, the method comprising:
 accepting inputs from a user that enable the user to enter a watering schedule including a run time, and to manually adjust a percentage adjustment value of a percentage adjustment feature configured to change said watering schedule by said percentage adjustment value;   receiving a signal representative of a current environmental condition on an irrigation site;   determining an irrigation adjustment value based on the signal;   implementing said percentage adjustment feature to increase or decrease the run time of the watering schedule by the percentage adjustment value; and   automatically increasing or decreasing said percentage adjustment value based on the irrigation adjustment value.   
     
     
         17 . The method of  claim 16  wherein the signal comprises a solar radiation signal from a solar radiation sensor located on the irrigation site and temperature signal from a temperature sensor located on the irrigation site. 
     
     
         18 . The method of  claim 17  wherein the irrigation adjustment value is further based on one or more constants configured to approximate local environmental conditions of the irrigation site. 
     
     
         19 . The method of  claim 18  further comprising determining an estimated irrigation value based on the signal and the one or more constants. 
     
     
         20 . The method of  claim 19  further comprising determining the irrigation adjustment value based at least in part on the estimated irrigation value.