Abstract
A device for automatic control of spraying height using five ultrasonic sensors has been developed for a 15-meter boom sprayer mounted on a tractor. The control device comprises an 8bit microprocessor and three interfaces: ultrasonic sensor measurement, hydraulic solenoid valve operation, and switch input. Five booms of the sprayer are controlled separately. The spraying height of the booms is controlled by the direction and the manipulated variable of the solenoid valve corresponding to the deflection between the set height and the detected spraying height. The manipulated variable depends on the boom height and the length of the hydraulic cylinder. From the fundamental test results, it was confirmed that the sprayer's booms are appropriately controlled according to the height of the ground surface.
