Automatically Adjusting Irrigation Controller

Abstract

Methods and devices are provided to automatically determine plant water requirements and adjust irrigation in order to make efficient use of water. In one implementation, an irrigation control unit comprises a memory storing historical values of a plurality of variables used at least in part in calculating plant water requirements, and at least one input adapted to receive signals corresponding to current values of one or more of the plurality of variables. The unit also comprises a processor coupled to the at least one input and the memory, the processor adapted to determine the plant water requirements at least in part using, for each of the plurality of variables, a current value in the event the current value is available and at least in part using, for each of the plurality of variables, a stored historical value in the event the current value is not available.

1 . An irrigation control unit comprising:
 a memory storing historical values of a plurality of variables used at least in part in calculating plant water requirements;   at least one input adapted to receive signals corresponding to current values of one or more of the plurality of variables;   a processor coupled to the at least one input and the memory, the processor adapted to determine the plant water requirements at least in part using, for each of the plurality of variables on a variable by variable basis, a current value in the event the current value is available and at least in part using, for each of the plurality of variables, a stored historical value in the event the current value is not available.   
     
     
         2 . The irrigation control unit of  claim 1  wherein the plant water requirements are based on a determination of an evapotranspiration (ET) value. 
     
     
         3 . The irrigation control unit of  claim 1  wherein the plurality of variables comprises two or more parameters selected from a group consisting of: temperature, solar radiation, humidity, wind speed and an amount of rainfall. 
     
     
         4 . The irrigation control unit of  claim 1  further comprising at least one sensor coupled to the at least one input. 
     
     
         5 . The irrigation control unit of  claim 4  wherein the at least one sensor comprises a sensor selected from a group consisting of: a temperature sensor, a solar radiation sensor, a humidity sensor, a wind speed and a rainfall sensor. 
     
     
         6 . The irrigation control unit of  claim 1  wherein the memory stores multiple sets of the stored historical values, each set corresponding to a different geographic region. 
     
     
         7 . The irrigation control unit of  claim 6  wherein, based on a user input, the processor selects a given set of the stored historical values for use in determining the plant water requirements. 
     
     
         8 . The irrigation control unit of  claim 7  wherein the user input comprises an input selected from a group consisting of: a zip code, a longitudinal coordinate, a latitudinal coordinate, and a map code. 
     
     
         9 . The irrigation control unit of  claim 1  wherein the signals received at the at least one input correspond to current values of the one or more of the plurality of variables for a geographic region local to the irrigation control unit. 
     
     
         10 . The irrigation control unit of  claim 1  further comprising:
 a first housing containing the irrigation control unit and an irrigation controller coupled to and controlling operation of flow control devices. 
 
     
     
         11 . The irrigation control unit of  claim 1  further comprising:
 a first housing containing the irrigation control unit, the first housing adapted to be coupled to a second housing containing an irrigation controller coupled to and controlling operation of flow control devices. 
 
     
     
         12 . The irrigation control unit of  claim 1  wherein the processor is adapted to determine, based on the plant water requirements, adjustments to a programmed watering schedule. 
     
     
         13 . The irrigation control unit of  claim 12  wherein the processor is adapted to generate signaling to cause the adjustments to the programmed watering schedule. 
     
     
         14 . The irrigation control unit of  claim 1  wherein the processor is adapted to determine a watering schedule in order to meet the plant water requirements. 
     
     
         15 . The irrigation control unit of  claim 1  wherein the stored historical values are stored in the memory prior to the irrigation control unit being sold. 
     
     
         16 . The irrigation control unit of  claim 1  wherein the processor is adapted to determine the plant water requirements at least in part using the current value for at least one of the plurality of variables and the stored historical value for at least one of the plurality of variables. 
     
     
         17 . A processor implemented method for use in irrigation control comprising:
 determining, for each of a plurality of variables used at least in part to determine plant water requirements, whether a current value is available; and   determining the plant water requirements at least in part using, for each of the plurality of variables on a variable by variable basis, the current value in the event the current value is available and at least in part using, for each of the plurality of variables, a stored historical value in the event the current value is not available.   
     
     
         18 . The method of  claim 17  wherein the determining the plant water requirements step comprises determining an evapotranspiration (ET) value. 
     
     
         19 . The method of  claim 17  wherein the plurality of variables comprises two or more parameters selected from a group consisting of: temperature, solar radiation, humidity, wind speed, and an amount of rainfall. 
     
     
         20 . The method of  claim 17  further comprising:
 receiving, for each of one or more of the plurality of variables, the current value from a sensor.