无人直升机飞行高度与速度对喷雾沉积分布的影响

Effects of flight altitude and speed of unmanned helicopter on spray deposition uniform

为了找出小型无人直升机喷洒农药时影响农药沉积的因素及各因素对农药沉积的影响程度,并通过试验制定相应的试验方法和规范,该文采用二因素三水平试验方法安排试验,研究了无人直升机喷雾沉积浓度,沉积均匀性与飞机飞行高度,飞行速度及两因素间的交互作用的关系,分别建立了试验指标之沉积浓度,沉积均匀性与飞行速度和飞行高度之间的关系模型。对试验样本进行方差分析和回归分析(显著性水平α取0.05),结果表明:飞行高度,飞行速度及两因素间的交互作用对沉积浓度的影响极显著,对应的P-value值分别为2.0684×10-4,8.2190×10-5,9.7052×10-5;飞行高度和飞行速度对沉积均匀性的影响极显著,对应的P-value值分别为9.8410×10-3,1.1550×10-3;两因素间的交互作用对沉积均匀性影响显著,对应的P-value值为2.5594×10-2。分别建立的沉积浓度,沉积均匀性与飞行速度和飞行高度之间的关系模型,在飞行速度和飞行高度区间范围内失拟不显著,对应的失拟性检验结果分别为:FLf=3.7024<F0.1(3,1)=53.5932,FLf=17.60<F0.1(3,1)=53.5932,可以为实际生产应用提供指导。小型无人直升机喷洒农药时,影响沉积浓度及均匀性的因素有:飞行高度,飞行速度及两因素间的交互作用。建立的沉积浓度,沉积均匀性与飞行高度和飞行速度两因素关系模型可以为实际生产应用提供指导。

In order to find out the factors and degree of influence affecting small unmanned helicopter spray deposition, and formulate the corresponding test methods and specifications through experimental results, this paper studied the relationship between spray deposition characteristics and flight height, flight velocity of an unmanned helicopter and the interaction between two factors, and arranged a test by a second factor three level test. An experiment was conducted with a diameter of 90 mm glass sample dish as collecting droplets sampling tools, setting up six sampling points, with the interval of sampling being 5 m, and each sample dish was placed on the top of wheat, about 0.8 m. Then 10 mL of distilled water was added in the sample plate in advance as a sample base to collect settlement droplets in the spray test. A 4 g/L carmine solution was selected as medium for spraying, monitored wind speed of flight direction refer to meteorological station monitoring method in spraying test, at the same time, monitored humidity and temperature. Then t the collected samples were measured by UV-2102 PCS type ultraviolet visible spectrophotometer, first, scan absorption wavelength of carmine solution, selecting λ=508 nm as the measurement wavelength to measure absorbance. Secondly, a carmine standard solution was prepared in 0, 0.025, 0.05, 0.075 and 0.1 g/L to establish a mathematical model of concentration and absorbance and convert concentration into absorbance under the established wavelength, and convert taken samples measurement results into concentration according to the mathematical model. Finally, absorbance of taken samples were converted into mass concentration, that is a quality of carmine per square centimeter as the experimental results for data analysis. Next, the significance level α = 0.05 was selected. The average concentration and the coefficient of variation to variance and regression analysis was selected to study the degree of effect of unmanned helicopter flight velocity, flight height, and interaction of these two factors to deposition concentration and deposition uniform. The analysis results showed that：flight height, flight velocity of unmanned helicopter, and the interaction between these two factors have a very significant impact on the deposition concentration, the respective P-value values is 2.0684×10-4, 8.2190×10-,5 and 9.7052×10-5; flight height, flight velocity of an unmanned helicopter has a very significant impact on the deposition uniformity, the respective P-value values are 9.8410×10-3 and 1.1550×10-3;the interaction between the two factors have a significant impact on the deposition uniformity, and the P-value values are 2.5594×10-2. The model established respectively between deposition concentration, deposition uniformity and flight height, flight velocity, in interval range of the flight velocity and flight height was not significant, and the respective regression equation lost to test is Fef=3.7024〈F0.1（3,1）=53.5932, FLf=17.60〈F0.1（3,1）=53.5932. These results can provide guidance for the actual production application. Therefore, the factors affecting deposition and uniformity are： flight altitude, flight speed, and the interaction between the two factors. The model established respectively between deposition concentration, deposition uniformity and flight height, and flight velocity can provide guidance for the actual production application.