The Toro Company

Larry Hawkes

Allan Morris Goldberg

Larry Kent Hopkins

James W Zimmerman

Michael J Grundy

Randall Pearson

A self-adjusting irrigation controller takes a pre-irrigation soil moisture reading prior to irrigation, chooses an amount of water to be dispensed corresponding to that reading from a table, and dispenses that amount of water. A predetermined length of time after the end of irrigation, the controller takes a post-irrigation soil moisture reading and compares the value of that reading to a predetermined target value. If the post-irrigation value differs substantially from the target value, the water amount corresponding to the pre-irrigation value in the table is adjusted to reduce that difference on the next scheduled irrigation cycle having that same pre-irrigation soil moisture reading. The target value is determined by watering the soil to field capacity, then computing the target value as a function of the reading of the sensor at field capacity. The controller thus converges toward an ideal runtime and follows changes in the environment. In the preferred embodiment, the soil moisture is indicated by sensor voltages, and the amount of water dispensed is governed by the runtime of the irrigation system.

Method and apparatus for optimizing soil moisture

A free-standing field irrigation controller is selectively programmed by a personal computer over a radio link. The computer is equipped with software that displays a screen with seven horizontal time bands representing one day each, arranged vertically to display one week's time. Box icons representing watering settings for a plurality of zones can be dragged and dropped onto the time bands, copied and modified thereon as desired, to form a freely selectable watering schedule. Other selectable screens allow odd-days or even-days watering, sophisticated interval watering, global watering time adjustment, and a variety of manual functions. Selectable portions of the main screen can be enlarged as desired. Based on the selected schedule, the computer calculates and displays the monthly cost of water. Selected zones can be temporarily disabled to deal with weather or maintenance issues. A handheld global shut-off and manual watering remote and/or a separate radio-linked computer may be used in field maintenance.

Growing community of inventors

San Diego, CA, United States of America

Larry Hawkes