Irrigation system
An irrigation system includes a valve that controls the flow of water through a sprinkler head, and a flow sensor that measures the water flow rate through the sprinkler head. In some embodiments, the valve is adjusted until the flow sensor measures a water flow rate that matches a first predetermined water flow rate. This is a first position for the valve. The valve opening is adjusted again by a set amount or until the flow sensor measures a water flow rate that matches a second predetermined water flow rate. This is a second position for the valve. The first and second predetermined water flow rates each correspond to a throw distance the water stream discharged from the sprinkler head will travel. This relationship between the water flow rate and distance is based on empirical data for the sprinkler. A second equation relating the valve opening to water flow rate, for a given pressure, is then used to estimate the water effective pressure. In some embodiments, the first and second valve positions and the first and second water flow rates are used to estimate the effective pressure using the second equation.
1. A method of calibrating a sprinkler comprising steps of:
controlling a flow rate of water through a sprinkler including setting a valve opening of a valve;
measuring the flow rate of water using a flow sensor;
adjusting the valve opening;
repeating the controlling, measuring, and adjusting steps a limited number of times;
identifying one of a plurality of pressure-dependent relationships between the flow rate and the valve opening for the valve based on the corresponding measured flow rates and valve openings;
determining a relationship between the valve opening and a throw distance, at which a water stream is discharged from the sprinkler, based on the identified pres sure-dependent relationship and a relationship between the flow rate and the throw distance for the sprinkler; and
controlling the operation of the sprinkler based on the relationship between the valve opening and the throw distance;
wherein determining a relationship between the valve opening and the throw distance comprises measuring a plurality of flow rates and throw distances for a plurality of valve settings.
2. A method of calibrating a sprinkler of an irrigation system comprising:
adjusting a valve setting of a valve of the sprinkler to a first valve setting, in which a water flow rate through the sprinkler reaches a first flow rate and a water stream discharged from the sprinkler reaches a first distance, using a controller;
recording at least the first valve setting in memory of the system using the controller;
adjusting the valve setting to a second valve setting, in which the water flow rate through the sprinkler reaches a second flow rate and a water stream discharged from the sprinkler reaches a second distance using the controller;
recording at least the second valve setting in memory of the system using the controller;
identifying one of a plurality of pressure-dependent relationships between the water flow rate through the sprinkler and the valve opening for the valve based on the first valve setting, the second valve setting, the first flow rate or the first distance, and the second flow rate or the second distance;
determining a first relationship between the flow rate and a throw distance for the sprinkler based on the first and second flow rates and the first and second distances;
determining a second relationship between the valve setting and the throw distance for the sprinkler based on the identified pressure-dependent relationship and the first relationship; and
configuring the sprinkler to operate based on the second relationship.
3. The method according to claim 2 , further comprising calculating an effective pressure for the sprinkler based on a change in the valve setting between the first and second valve settings, and the difference between the first and second flow rates, and storing the effective pressure in memory using the controller.
4. The method according to claim 3 , further comprising retrieving the stored effective pressure from the memory, and controlling the operation of the sprinkler based on the effective pressure using the controller.
5. An irrigation system comprising:
one or more sprinklers;
a valve associated with each sprinkler and configured to control a water flow through the sprinkler;
a flow sensor associated with each sprinkler and configured to measure a water flow rate through the sprinkler;
at least one controller configured to perform a method of calibrating each of the one or more sprinklers comprising:
adjusting a valve setting of the valve to a first valve setting, in which the water flow rate through the sprinkler reaches a first flow rate and a the water stream discharged from the sprinkler reaches a first distance using the at least one controller;
recording at least the first valve setting in memory of the system using the controller;
adjusting the valve setting to a second valve setting, in which the water flow rate through the sprinkler reaches a second flow rate and a water stream discharged from the sprinkler reaches a second distance using the at least one controller;
recording at least the second valve setting in memory of the system using the at least one controller;
identifying one of a plurality of pressure-dependent relationships between the water flow rate through the sprinkler and the valve opening for the valve based on the first valve setting, the second valve setting, the first flow rate or the first distance, and the second flow rate or the second distance;
determining a first relationship between the flow rate and a throw distance for the sprinkler based on the first and second flow rates and the first and second distances;
determining a second relationship between the valve setting and the throw distance for the sprinkler based on the identified pressure-dependent relationship and the first relationship; and
configuring the sprinkler to operate based on the second relationship.
6. The system according to claim 5 , wherein the method of calibrating includes controlling each of the sprinklers to perform a controlled watering operation based on the second relationship.