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.

1 . An ET based irrigation system, comprising:
 a stand alone irrigation controller with a seasonal adjust feature;   a stand alone weather station including at least one environmental sensor; and   a stand alone ET unit operatively in communication with the irrigation controller and the weather station including 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.   
   
   
       2 . The system of  claim 1  wherein the programming of the ET unit provides the capability for automatically modifying the watering schedule through the seasonal adjust feature based on the estimated ET value as increased or decreased by the user through an inputted overall watering adjustment. 
   
   
       3 . The system of  claim 1  wherein the programming of the ET unit provides the capability for entering a no-water window that automatically overrides the watering schedule. 
   
   
       4 . The system of  claim 1  wherein the programming of the ET unit provides the capability for automatically shutting down any watering otherwise scheduled based on a detected event. 
   
   
       5 . The system of  claim 1  wherein the weather station includes a solar radiation sensor, a temperature sensor and a rain sensor and the estimated ET value is calculated using signals from the solar radiation sensor and the temperature sensor and a plurality of pre-programmed constants. 
   
   
       6 . The system of  claim 1  wherein the ET unit is operatively connected to the weather station through a wireless communications link. 
   
   
       7 . The system of  claim 1  wherein the ET unit is configured to receive power from the irrigation controller. 
   
   
       8 . The system of  claim 1  wherein the weather station includes a solar radiation sensor, a temperature sensor and a rain sensor and the estimated ET value is calculated using signals from the solar radiation sensor and the temperature sensor and a plurality of pre-programmed constants and where data entered by the user determines at least one constant of a given site. 
   
   
       9 . The system of  claim 1  wherein the ET unit modifies the watering schedule of the irrigation controller through a data port of the irrigation controller. 
   
   
       10 . The system of  claim 2  wherein the ET unit includes a pair of manually actuable controls configured to enable a user to input the overall watering adjustment by selectively increasing and decreasing an estimated maximum ET setting that is a constant used in calculating the estimated ET value. 
   
   
       11 . An ET based irrigation system, comprising:
 an interface that enables a user to select and/or enter a watering schedule;   a memory for storing the watering schedule;   at least one sensor for generating a signal representative of an environmental condition;   a processor capable of calculating an estimated ET value based at least in part on the signal from the sensor; and   a program executable by the processor to enable the processor to generate commands for selectively turning a plurality of valves ON and OFF in accordance with the watering schedule, the program including a seasonal adjust feature that provides the capability for automatically modifying the watering schedule based on the estimated ET value to thereby conserve water while maintaining plant health.   
   
   
       12 . The system of  claim 11  wherein the interface further enables a user to input an overall watering adjustment and further wherein the program provides the capability for automatically modifying the watering schedule through the seasonal adjust feature based on the estimated ET value as increased or decreased by the user through the inputted overall watering adjustment. 
   
   
       13 . The system of  claim 11  wherein the program calculates the estimated ET based on the signal from the environmental sensor and a plurality of pre-programmed constants and where data entered by the user determines at least one constant of a given site. 
   
   
       14 . The system of  claim 11  wherein the program calculates the estimated ET based on the signal from the environmental sensor and a plurality of pre-programmed constants. 
   
   
       15 . The system of  claim 11  wherein the interface includes a pair of manually actuable switches for selectively increasing and decreasing the estimated ET value. 
   
   
       16 . A method of controlling a plurality of valves on an irrigation site, comprising the steps of:
 selecting and/or creating a watering schedule;   storing the watering schedule;   generating a signal representative of an environmental condition on an irrigation site;   calculating an estimated ET value based at least in part on the signal;   selectively turning a plurality of valves located on the irrigation site ON and OFF in accordance with the watering schedule; and   automatically modifying the watering schedule based on the estimated ET value using a seasonal adjust algorithm to thereby conserve water while maintaining the health of plants on the irrigation site.   
   
   
       17 . The method of  claim 16  and further comprising the step of inputting an overall watering adjustment and automatically modifying the watering schedule through the seasonal adjust algorithm based on the estimated ET value as increased or decreased by the inputted overall watering adjustment. 
   
   
       18 . The method of  claim 16  wherein the estimated ET value is calculated based on the signal and a plurality of predetermined constants. 
   
   
       19 . The method of  claim 16  wherein the estimated ET value is calculated based on signals generated by a solar radiation sensor and a temperature sensor located on the irrigation site, and a plurality of predetermined constants. 
   
   
       20 . The method of  claim 19  wherein data based on the signals generated by the sensors is transmitted wirelessly across the irrigation site. 
   
   
       21 . The method of  claim 16  wherein the estimated ET value is calculated based on the signal and a plurality of predetermined constants and where data entered by the user determines at least one constant of a given site. 
   
   
       22 . The method of  claim 16  wherein the estimated ET value is calculated based on signals generated by a solar radiation sensor and a temperature sensor located on the irrigation site, and a plurality of predetermined constants and where data entered by the user determines at least one constant of a given site. 
   
   
       23 . A weather station for use with an irrigation controller, comprising:
 a housing;   a rain sensor supported by the housing;   a solar radiation sensor supported by the housing;   a temperature sensor supported by the housing;   a micro-controller supported by the housing and connected to the sensors;   a communications interface for permitting communications between the micro-controller and an irrigation controller; and   firmware executable by the micro-controller for periodically sampling the output of the sensors and providing representative sensor data to the irrigation controller.   
   
   
       24 . The weather station of  claim 23  wherein the micro-controller is connected to the solar radiation sensor through an amplifier. 
   
   
       25 . The weather station of  claim 23  wherein the micro-controller is connected to the temperature sensor through an A/D interface. 
   
   
       26 . The weather station of  claim 23  wherein the micro-controller is connected to the rain sensor through an interface circuit. 
   
   
       27 . The weather station of  claim 23  wherein the solar radiation sensor includes a photodiode. 
   
   
       28 . The weather station of  claim 23  wherein the rain sensor includes at least one moisture absorbing member made of a hygroscopic material. 
   
   
       29 . The weather station of  claim 23  wherein the rain sensor includes a Hall effect sensor. 
   
   
       30 . The weather station of  claim 23  wherein the communications interface enables hard wired communication between the micro-controller and the irrigation controller. 
   
   
       31 . The weather station of  claim 23  wherein the communications interface enables wireless communication between the micro-controller and the irrigation controller. 
   
   
       32 . The weather station of  claim 23  wherein the firmware enables the micro-controller to respond to requests sent from the irrigation controller for sensor data via the communications interface. 
   
   
       33 . A weather station for use with an irrigation controller, comprising:
 a housing;   a rain sensor supported by the housing;   a solar radiation sensor supported by the housing;   a temperature sensor supported by the housing;   a micro-controller supported by the housing and connected to the sensors;   a communications interface for permitting communications between the micro-controller and an ET interface;   a communications interface for permitting communications between the ET interface and an irrigation controller; and   firmware executable by the micro-controller for periodically sampling the output of the sensors and providing representative sensor data to the ET interface.   
   
   
       34 . The weather station of  claim 33  wherein the micro-controller is connected to the solar radiation sensor through an amplifier. 
   
   
       35 . The weather station of  claim 33  wherein the micro-controller is connected to the temperature sensor through an A/D interface. 
   
   
       36 . The weather station of  claim 33  wherein the micro-controller is connected to the rain sensor through an interface circuit. 
   
   
       37 . The weather station of  claim 33  wherein the solar radiation sensor includes a photodiode. 
   
   
       38 . The weather station of  claim 33  wherein the rain sensor includes at least one moisture absorbing member made of a hygroscopic material. 
   
   
       39 . The weather station of  claim 33  wherein the rain sensor includes a Hall effect sensor. 
   
   
       40 . The weather station of  claim 33  wherein the communications interface enables hard wired communication between the micro-controller and the irrigation controller. 
   
   
       41 . The weather station of  claim 33  wherein the communications interface enables wireless communication between the micro-controller and the irrigation controller. 
   
   
       42 . The weather station of  claim 33  wherein the firmware enables the micro-controller to respond to requests sent from the irrigation controller for sensor data via the communications interface.