Abstract: A GPS-based control system for irrigation systems includes a power supply, a nonvolatile memory for storing a first set of coordinates corresponding to a reference position for the irrigation system, circuitry for receiving GPS data and using the data to generate a second set of coordinates corresponding to a current position of the irrigation system, and a microprocessor for calculating the azimuth and the distance between the reference position and the current position using the first and second sets of coordinates. The control system communicates with a main controller of the irrigation system to control a function of the irrigation system, such as stopping, reversing, end gun operation, application rate, or other auxiliary output, at a selected distance or azimuth value of the current position relative to the reference position. The control system can be used with either a center pivot irrigation system or a linear move irrigation system.

Abstract: A guidance system for controlling the steering of a swing arm on a center pivot irrigation system is provided through the use of two satellite signal receiving antennas associated with a drive tower for the swing arm. The signal receiving antennas are mounted from the swing tower so that one of the antennas is in a position forwardly of a steerable wheel for the tower and the other antenna is located in a position rearwardly of the steerable wheel. The signal receiving antennas are mounted in such fashion that they rotate in a direct relation to the steering of the steerable wheel so as to provide position information for the steering of the drive tower that more efficiently and effectively maintains the drive tower on a desired path of travel.

Abstract: A GPS-based control system for irrigation systems includes a power supply, a nonvolatile memory for storing a first set of coordinates corresponding to a reference position for the irrigation system, circuitry for receiving GPS data and using the data to generate a second set of coordinates corresponding to a current position of the irrigation system, and a microprocessor for calculating the azimuth and the distance between the reference position and the current position using the first and second sets of coordinates. The control system communicates with a main controller of the irrigation system to control a function of the irrigation system, such as stopping, reversing, end gun operation, application rate, or other auxiliary output, at a selected distance or azimuth value of the current position relative to the reference position. The control system can be used with either a center pivot irrigation system or a linear move irrigation system.

Abstract: A guidance system for providing a steering control for a swing arm on a center pivot irrigation system is provided through the use of two satellite signal receivers. A first signal receiver is located at the center pivot to provide calculated position information for a comparison with the known position of the center pivot. An error signal is generated and is utilized to adjust position information provided by the second signal receiver to produce an improved position information for the swing arm. Such improved position information is compared to the desired path of travel for the swing arm and a steering signal is generated therefrom, which steering signal controls the steering of the swing arm along its desired path of travel.