An effective spray drift-reducing method for a plant-protection unmanned aerial vehicle

Yayong Chen,Shaoming Luo,Yu Tang,Chaojun Hou,Jiajun Zhuang,Jintian Lin

doi:10.25165/j.ijabe.20191205.4289

Abstract

A spraying system for a plant-protection unmanned aerial vehicle (UAV) was designed to reduce spray drift. A custom low-speed wind tunnel was constructed to generate a wind speed ranging from 0 to 5.92 m/s. The results showed that the wind speed was attenuated with an increase in distance. To compensate for the attenuation, a linear-fitting model was adopted. Then, the relationship between the spraying pressure and atomization rate was analyzed, and a fuzzy algorithm was adopted to adjust the spraying angle and pressure according to the wind speed and its changing rate. Finally, an evaluation of the proposed system in the compensated wind tunnel was conducted, and the drift distance was reduced by 33.7% compared with the system without adjustment of the spraying angle and pressure. Keywords: plant-protection UAV, spray drift, spraying pressure, spraying angle, fuzzy algorithm DOI: 10.25165/j.ijabe.20191205.4289 Citation: Chen Y Y, Hou C J, Tang Y, Zhuang J J, Lin J T, Luo S M. An effective spray drift-reducing method for a plant-protection unmanned aerial vehicle. Int J Agric & Biol Eng, 2019; 12(5): 14–20.

Highlights

Plant-protection unmanned aerial vehicles (UAVs) are used to spray pesticides and have become increasingly common, due to the speed and effectiveness of the spraying operation[1,2,3]
During the spraying process, when the pesticide liquid is atomized through the nozzle, droplets of less than 150 μm are more sensitive to drift caused by wind[4,5], which can lead to damage to susceptible off-target crops, reduce the effectiveness of the pesticide, and cause environmental contamination, such as water pollution and illegal pesticide residues[6,7]
The spray drift of pesticides away from the target compromises the effectiveness of UAV spraying and limits its wide application[8,9]

Summary

Introduction

Plant-protection unmanned aerial vehicles (UAVs) are used to spray pesticides and have become increasingly common, due to the speed and effectiveness of the spraying operation[1,2,3]. Many researchers have focused on the reduction of spray drift and have found that the nozzle type, droplet size, working path of the UAV, and wind speed are the main influencing factors[10,11,12]. To reduce spray drift and pesticide residues, Zhao et al.[15] investigated residues sprayed on wheat using different spraying nozzles and found that the combination of a flat-fan nozzle (AD120-02) and a guided-baffle shield sprayer achieved the optimum spray drift for these plants. Ellis et al.[24] investigated a mathematical model of the droplet drift mass center distance versus electrostatic voltage and wind speed to determine optimum operational parameters for a conical electrostatic nozzle. Many researchers have systematically investigated the reduction of spray drift, the use of a fuzzy algorithm method to adjust the spraying angle and pressure to achieve reduction of spray drift has seldom been reported

Methods

Results

Conclusion