In recent years, unmanned aerial vehicles have emerged as a new technology in the field of agriculture. Plant protection drones have become the preferred method for farmers due to their high spraying efficiency, improved atomization of poisons and pesticides, and ability to spray during crop growth in challenging field conditions where agricultural machinery movement is limited. It is crucial to eva‎luate the distribution and deposition of droplets in aerial spraying in order to determine the efficiency of the spraying procedure. In this study, the performance characteristics of the Iranian-produced Pelican 1 plant protection drone were investigated in two stages. The first stage included calibration, feature extraction such as spraying rate and effective spray width in a static test, and field eva‎luation. Subsequently, the examination of pesticide drift and the estimation of pesticide deposition in non-target areas during field eva‎luation and under flight at different altitudes and speeds were carried out. A spray droplet recording system was developed and constructed for the purpose of static testing and field eva‎luation. The system comprises a chassis, driven and movable rollers, a stepper motor, LED lighting lamps, a battery, a power supply, a camera, and Mylar sheet. Its primary function was to estimate the size of spray droplets. A spectrometer system was also used to eva‎luate the deposition amount in the field. The samples' spectra were measured using a transmittance method, and a range of pre-processing techniques, including Smoothing, Normalizing, Multiplicative scatter correction, Baseline correction, Standard normal variable, First derivative, and Second derivative, were applied. Colors and spectroscopy technology are frequently utilized to assess the deposition of plant protection drones due to their convenient and cost-effective detection process. A spray solution was prepared for all tests and eva‎luations, consisting of water, 10 grams of Tartrazine food color, and 125 milliliters of Diazinon insecticide per liter of water. The plant protection drone underwent assessment at the educational-research farm of Isfahan University of Technology. The eva‎luation involved two flight heights (3 and 5 meters) and three flight speeds (5, 6, and 7 meters per second) as independent variables, while spray solution concentration, coverage percentage, VMD, and NMD were considered as dependent variables. The outcomes indicated that the plant protection drone under investigation possesses a spray width and length of approximately 2.5 meters for each nozzle. When two nozzles are utilized, the total spray width expands to 5 meters. Achieving the smallest coefficient of variation requires adjusting the distance between two neighboring flight paths to 2.6 meters. The VMD and NMD indices show an increase as the distance from the nozzle location increases both longitudinally and laterally. The study showed that the uniformity index of droplet spectrum (VMD/NMD) was greater near the nozzle compared to points farther from it. Analysis of spray height coverage percentage laterally demonstrated that the highest coverage percentage at all heights was found at points positioned 2 meters longitudinally from the nozzle and at the nearest height to the ground surface (half-meter distance). The variability of the deposition amount, which ranged from 0.0 to 0.096 microliters per square centimeter, was observed. It was observed that droplet deposition was more pronounced at the centerline (flight path), while diminishing as the distance from the centerline increased. At a speed of 6 meters per second and a height of 3 meters, the flight recorded a minimum drift ratio of 42.18%. A substantial decrease in altitude contributed to the reduction in drift ratio. The indices of VMD and NMD were observed to be smaller in field testing as compared to static testing, primarily due to the wind effect caused by rotor rotation and opposing wind.

مهرنوش جعفري , احمد ميره اي

امين اله معصومي , حميدرضا عشقي زاده

علي قاسمي , نفيسه پورجواد