Automatic Adjustable Spraying Device for Site-Specific Agricultural Application

Abstract

This paper presents a device for accurate pesticide spraying capable of dealing with amorphous shapes and variable-sized targets. The device includes a single spray nozzle with an automatically adjustable spraying angle, color camera, and distance sensors, all mounted on a pan tilt unit. The site-specific spraying device aims to spray specific targets while reducing the use of pesticides. The spraying diameter is set as the minimum closing circle diameter according to the shape and size of the target. Two preliminary experiments were conducted in order to evaluate the spray nozzle flow rate in relation to the spray diameter and the spray diameter in relation to the nozzle’s angular position. A main outdoor experiment was conducted to evaluate the complete spraying device using artificial targets of varying sizes. The results indicated that the spraying device is capable of reducing the amount of pesticides applied. An economic analysis estimates that up to 45% of pesticide reduction is possible when using the suggested spraying method. Actual savings depend on the spraying durations, target size, and distribution. Note to Practitioners —This paper focuses on the development of a site-specific sprayer solution. The developed device aims to reduce pesticide application by spraying individual targets specifically by setting the diameter of the spraying according to the shape and size of the target. The core of the paper is a detailed description of a spraying device able to change its spraying diameter according to the detected target. A working procedure to calibrate and validate such a device is included. We believe that such a device can be used in modern agriculture and can be combined with a robotic sprayer navigating autonomously along crop fields. Such a device will contribute to reduced pesticide application.