小型植保无人机喷雾参数对橘树冠层雾滴沉积分布的影响

【目的】探索小型植保无人机对果树喷施作业的雾滴沉积分布效果及应用前景,研究小型植保无人机喷雾参数对橘树冠层雾滴沉积分布的影响。【方法】采用三因素(飞行高度、飞行速度、喷施流量)的正交试验,应用小型六旋翼植保无人机进行喷雾试验。【结果】根据雾滴沉积密度和雾滴沉积均匀性结果,较佳的作业参数是喷头流量1.0 L·min~(-1)、作业高度2.5 m、作业速度4 m·s~(-1),影响雾滴沉积密度的主次顺序依次为作业速度、作业高度、喷头流量;根据雾滴沉积穿透性结果,作业高度均为2.0 m的试验号2(作业速度4 m·s~(-1),喷头流量0.6 L·min~(-1))和试验号8(作业速度1 m·s~(-1),喷头流量1.0 L·min~(-1))中雾滴沉积穿透性分别为22.21%和22.41%,其雾滴覆盖密度大且穿透性较好;影响雾滴沉积穿透性的因素主次顺序为作业高度、作业速度、喷头流量。【结论】针对植保无人机旋翼风场的影响和橘树独特的树形结构,对植保无人机的作业参数进行了优选,以保证航空喷施作业雾滴在橘树冠层的有效沉积分布。本试验研究可为小型无人机对果树的合理喷施、提高喷施效率提供参考和指导。

Effects of spraying parameters of small plant protection UAV on droplets deposition distribution in citrus canopy

[Objective] To explore droplet deposition distribution patterns from aerial spraying and the application prospect of small plant protection unmanned aerial vehicle (UAV) for fruit trees, and study the influence of spraying parameters of UAV on droplets deposition distribution in citrus canopy.

Spray test with six-rotor plant protection UAV was arranged by an orthogonal test of three factors (flight height, flight velocity, nozzle flow rate).[Result] SPreferred spraying operation parameters for small plant protection UAV were 2.5 m flight height, 4.0 m·s^–1 flight speed and 1.0 L·min^–1 nozzle flow rate based on the test results of density and uniformity of deposited droplets. The factors that affected the density of deposited droplets were in order of flight velocity, flight height, and nozzle flow rate. Test No.2 with 2.0 flight height, 4 m·s^–1 flight speed, 0.6 L·min^–1 nozzle flow rate and No.8 with 2.0 m flight height, 1 m·s^–1 flight speed, 1.0 L·min^–1 nozzle flow rate resulted in relatively high density and penetrability of deposited droplets, and the penetrability of droplets were 22.21% and 22.41% respectively. The factors that affected the penetrability of deposited droplets were in order of flight height, flight velocity, and nozzle flow rate.[Conclusion] Due to the influence of the wind field of UAV rotor and the unique structure of citrus, the operating parameters of plant protection UAV should be optimized to ensure effective deposition and distrubition of droplets in citrus canopy from aerial spraying. This research can provide reference and guidance for reasonable spraying using small UAV on fruit trees, for improving the spraying efficiency.