Controle automático da altura das barras de um pulverizador agrícola

Abstract

The project consists in the development of the prototype of a height controller for the boom sprayer Advance 2000 AM18 of the Jacto brand. The original factory implement has an electro-hydraulic control of the boom, and the actuation is manual using the up and down keys. The new developed system, at first, measures the distance from the boom to the ground, then processes the information and finally acts on height correction. Two ultrasonic sensors were used at different points on the boom. Data processing is performed on the ATmega2560 microcontroller embedded in the Arduino MEGA development kit. The movement of the structure is commanded with hydraulic pistons driven by 8 solenoids, which are controlled through a relay module. The control model is closed loop. The controller logic is a 3-window ONOFF, which, has been developed in order to reduce the frequency of activation of the solenoid coils, intentionally, increases the life time of the components. Tests were done with the equipment on soybean with vegetative height of approximately 40 cm. The results showed fast, controlled and stable responses. In future works, the number of sensors must be increased in order to make the system redundant. In fact, it has been proven that the system is viable and can be implemented.