A prototype spraying system built around a quadruple nozzle body and sophisticated software could be a look at the future of precision agricultural sprayers.

The system, which will be integrated with GPS navigation systems, will independently control an unlimited number of nozzles along a boom. For example, 192 nozzles with bodies spaced every 20 in. across an 80-ft. boom could have rates varied along the boom and enabled by-the-nozzle section control.

The system is being developed by the German spray equipment manufacturer Altek International and South Dakota-based Harrison Ag Technologies, which specializes in precision machine-control software and related hardware. The companies exhibited a prototype at the Midwest Ag-Industries Exposition in August.

“This system can maintain uniform application rates across the boom width while the sprayer is rounding a curve or accelerating,” says Richard Riley, Altek International managing director. This eliminates over-application on the slow end of a turning boom, and under-application on the fast end.

In addition to its variable-rate capabilities, the spraying system also will be able to manage spray particle size and keep spray pressure stable over a range of speeds by switching nozzles as the sprayer speeds up and slows down, says John Harrison of Harrison Ag Technologies.

Quadruple nozzle body

Altek’s Multi-Spray DC (direct control) quadruple nozzle body is at the heart of the system. In addition to providing spaces for four nozzles, the body includes four solenoids to turn each nozzle on and off.

“You can turn any of four nozzles on, or any combination, so you have 16 possible rate combinations with each nozzle body,” says Harrison, who has customized Harrison Ag Tech’s SmartNozzle software to drive the system.

Solenoids turn nozzles on and off based on electronic commands sent via Controller Area Network (CAN) modules arrayed along the boom. Changes are nearly instantaneous as solenoids respond to electronic commands sent via the CAN bus, Riley notes.

Particle size optimized

The 16 nozzle combinations at each nozzle body will allow operators to customize spray particle size to emphasize drift control or maximum coverage. Particle size preferences are set in the software, which chooses appropriate nozzle combinations to achieve the preferred particle size at a given speed. As operating speed changes, the software continuously switches to new nozzle combinations to meet particle size parameters.

Other system features include pre-charging while the sprayer is off and turning in a headland. This allows the sprayer to begin delivering the appropriate rate as soon as it leaves the headland. The system also is expected to have a statistically based monitoring system that will allow it to detect and warn the operator of a malfunction, such as a plugged nozzle.

The companies have not set pricing for the system, which should be available on select new sprayers in 2012.