Name
Title | ||
|---|---|---|
Design and control of precision drop-on-demand herbicide application in agricultural robotics |
Abstract | ||
|---|---|---|
Drop-on-demand weed control is a field of research within Precision Agriculture, where the herbicide application is controlled down to individual droplets. This paper focuses on the fluid dynamics and electronics design of the droplet dispensing. The droplets are formed through an array of nozzles, controlled by two-way solenoid valves. A much used control circuit for opening and closing a solenoid valve is a spike and hold circuit, where the solenoid current finally is discharged over a Schottky diode on closing. This paper presents a PWM design, where the discharge is done by reversing the polarity of the voltage. This demands an accurate timing of the reverse spike not to recharge and reopen the valve. The PWM design gives flexibility in choosing the spike and hold voltage arbitrarily, and may use fewer components. Calculations combined with laboratory experiments verify this valve control strategy. In early flight the stability of the tail, or filament, is described in theory by the Ohnesorge number. In later flight, when a droplet shape has formed, the droplet stability is governed by the Weber number. These two considerations have opposite implications on the desired surface tension of the fluid. The Weber number is more important for longer distances, as the filament satelites normally catch up and join the main droplet in flight. |
Year | DOI | Venue |
|---|---|---|
2014 | 10.1109/ICARCV.2014.7064570 | Control Automation Robotics & Vision |
Keywords | Field | DocType |
Schottky diodes,agricultural machinery,agrochemicals,computational fluid dynamics,industrial robots,nozzles,pulse width modulation,surface tension,valves,Ohnesorge number,PWM design,Schottky diode,Weber number,agricultural robotics,drop-on-demand weed control,droplet dispensing,droplet stability,electronics design,fluid dynamics,precision agriculture,precision drop-on-demand herbicide application,solenoid valves,spike and hold circuit,surface tension | Weber number,Solenoid valve,Control theory,Computer science,Voltage,Reversing,Pulse-width modulation,Control engineering,Nozzle,Ohnesorge number,Solenoid | Conference |
ISSN | Citations | PageRank |
2474-2953 | 1 | 0.43 |
References | Authors | |
0 | 5 | |
Name | Order | Citations | PageRank |
|---|---|---|---|
| Frode Urdal | 1 | 1 | 0.77 |
| Trygve Utstumo | 2 | 1 | 0.77 |
| Jan Kare Vatne | 3 | 1 | 0.43 |
| Simen Andreas Adnoy Ellingsen | 4 | 1 | 0.43 |
| Jan Tommy Gravdahl | 5 | 327 | 43.60 |