Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Performance Evaluation on Electronic Control Systems for Field Sprayers Using Programmable Logic Controllers

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan

Citation:  Pp. 272-278 in Proceedings of the World Congress of Computers in Agriculture and Natural Resources (13-15, March 2002, Iguacu Falls, Brazil)  701P0301.(doi:10.13031/2013.8341)
Authors:   U.R. Antuniassi, Z.N. Figueiredo, W.P.A. de Carvalho and D.R. Pinto
Keywords:   Precision Agriculture, Instrumentation and control, Equipment automation

The aim of this study was to develop a laboratory method for time response evaluation on electronically controlled spray equipment using Programmable Logic Controllers (PLCs). For that purpose, a PLC controlled digital drive inverter was set up to drive an asynchronous electric motor linked to a centrifugal pump on a experimental sprayer equipped with electronic flow control. The PLC was operated via RS232 serial communication from a PC computer. A user program was written to control de motor by adjusting the following system variables, all related to the motor speed: time stopped; ramp up and ramp down times, time running at a given constant speed and ramp down time to stop the motor. This set up was used in conjunction with a data acquisition system to perform laboratory tests with an electronically controlled sprayer. Time response for pressure stabilization was measured while changing the pump speed by 20%. The results showed that for a 0.2 s ramp time increasing the motor speed, as an example, an AgLogix Flow Control system (Midwest Technologies Inc.) took 22 s in average to readjust the pressure. When decreasing the motor speed, this time response was down to 8 s. General results also showed that this kind of methodology could make easier the definition of standards for tests on electronically controlled application equipment.

(Download PDF)    (Export to EndNotes)