植保无人机低空低量施药雾滴沉积飘移分布立体测试方法

随着植保无人机在中国的广泛使用,植保无人机的沉积分布均匀性与雾滴飘移流失也引起各方面的重视。目前,针对植保无人机施药雾滴沉积飘移的测试方法较少,且着重于从沉积或飘移中某一方面分析植保无人机雾滴沉积飘移规律,未对作业中全方位的雾滴的沉积飘失规律进行系统测试。该文基于国际标准ISO22866和ISO24253建了1套针对低空低量植保无人机的立体测试方法,分别在地面布置沉积和飘移收集器,在空中架设立体沉积和空中飘移收集器,结合航拍影像所获取的植保无人机准确作业参数,对4个型号植保无人机分别搭载德国Lechler公司的IDK120-015和TR80-0067喷头进行了测试,系统分析了无人机周边的总沉积以验证方法准确性,计算了总地面沉降以表征可利用部分和空中耗散以评估环境风险。结果表明,各植保无人机地面沉积率在53.6%~76.6%,地面飘移率最高17.4%,空中飘移率可高达14.7%;该测试系统可收集62.4%~101.7%无人机喷洒出的雾滴。测试的4种植保无人机在搭载IDK喷头后均明显降低了雾滴飘移,但也同时降低地面沉积率;各植保无人机在搭载2种喷头时沉积规律不同,不同植保无人机设计需要选择不同喷头。该测试方法能够有效的收集并分析植保无人机在作业区域的雾滴立体分布状态,可为植保无人机综合评估提供新的参考依据。

Stereoscopic test method for low-altitude and low-volume spraying deposition and drift distribution of plant protection UAV

With the widespread application of plant protection unmanned aircraft vehicle(UAV)in China,the application technology of plant protection UAV has attracted attention,and the environmental risk from the uniformity of deposition distribution and droplet drift loss is also an important question.At present,there are few test methods focusing on the droplet distribution in the environment of plant protection UAV.In this paper,a set of stereoscopic test methods for low-altitude low-volume plant protection UAV was designed mainly based on the international standards ISO 22866 and ISO 24253.The methods concluded two parts of the ground distribution and airborne distribution.The ground distribution was collected by the standard collectors(Petri dishes and Polyvinyl Chloride card)arranged on the ground according to the ISO standard.The airborne distribution mainly used a vertical sedimentation testing framework.The droplets of aerial drift were collected by Polytetrafluoroethylene lines and rotary tube brushes.The accurate flight parameters(fight speed and working width)of each test were captured by a camera UAV(Phantom 4A,produced by DJI)above the ground 80 m.Two three-axis ultrasonic anemometers(Gill,USA)were installed above ground 2 and 5 m respectively,which could obtain real-time meteorological data including the wind speed,wind direction and temperature.There were four types plant protection UAVs for testing,the MG-1s(DJI,8 rotors),3WQF-120-12(Anyang Quanfeng,1 rotor),3W-TTA6-10(Beifang Tiantu,6 rotors)and 3W-TTA8-20(Beifang Tiantu,8 rotors),they were tested respectively with the nozzles of IDK 120-015 and TR 80-0067 produced by Lechler(Germany).A new calculation method was proposed,and total deposition around UAV was calculated for verifing the accuracy of method.Total ground sedimentation and aerial disappearance were calculated to represent all available pesticide,and evaluate the environmental risk respectively.The results showed that the ground deposition rate of all tests was between 53.6%to 76.6%,the highest ground drift rate was rich to 17.4%,and the airborne drift rate could be as high as 14.7%.This test system could collect 62.4%-101.7%droplets around the UAV sprayed by plant protection UAV.The drifts of 4 tested plant protection UAV installed IDK nozzles were obviously less than that with TR nozzles,meanwhile,the nozzle changing also reduced the ground deposition in some tests.Different plant protection UAVs had different distribution regular patterns of deposition when they installed TR or IDK nozzles.It meant the designs of different plant protection UAVs needed to select the right nozzles after finishing the distribution test for different types of nozzles.Thus,the most suitable nozzle type of each UAV should be tested and selected before the UAV working.This test method can effectively and systematically collect and analyze the droplets distribution of plant protection UAV and the drift regularity in the work area,which can provide a new reference for the comprehensive evaluation of the plant protection UAV.