植保无人机有效喷幅宽度的准确评定是农业航空精准作业的前提,对其作业航线的规划及喷施作业质量的提升均有着重要意义。该文以不同参数的单旋翼植保无人机和多旋翼植保无人机为例,分别通过12架次不同飞行参数下的航空喷施试验及目前国内常用的雾滴密度判定法和50%有效沉积量判定法来评定植保无人机的有效喷幅宽度,并根据雾滴处理软件Deposit Scan对水敏纸等采集卡上的图像处理原理对不同评定方法进行了深入分析。结果表明:50%有效沉积量判定法更适于雾滴粒径相对较大的3WQF120-12型植保无人机有效喷幅宽度的评定,且评定的平均有效喷幅宽度为≥4.44 m;雾滴密度判定法更适于雾滴粒径相对较小的P-20型植保无人机有效喷幅宽度的评定,且评定的平均有效喷幅宽度为≥2.58 m;评定的有效喷幅结果与实际情况相符合。另外,由分析可知,由于当前图像处理技术的限制,不同粒径大小的雾滴斑点图像,软件Deposit Scan所产生的相对误差不同,因此,应根据植保无人机喷施雾滴粒径的范围选择合适的有效喷幅宽度评定方法。该结果为不同参数的植保无人机选择较优的有效喷幅评定方法提供了指导,降低了航空喷施作业的重喷率和漏喷率,提高了植保无人机航空喷施作业质量,可为植保无人机精准喷施作业的实施提供参考。
With the extensive application of plant protection UAV(unmanned aerial vehicle) in China, the research of its low-attitude and low-volume spray technology has gradually become a research hotspot. At present, the domestic research on the aerial spraying application of plant protection UAV mainly focuses on the effect of aerial spraying operation parameters on the distribution of droplet deposition, while neglecting the evaluation and test of the effective spraying width of aerial spraying by plant protection UAV. It is a prerequisite for precision spraying operation of agricultural aviation to evaluate the effective spraying width of plant protection UAV accurately, and it has great significance to the planning of operation route and the improvement of spraying quality. Therefore, the effective spraying width of single-rotor and multi-rotor plant protection UAV was evaluated with the evaluation method of droplet density and 50% effective deposition amount method which were commonly used in China by the tests of 12 times with different flight parameters; and different evaluation methods were deeply analyzed with the image processing principle of Deposit Scan, which is an image processing software used to analyze the results of droplet deposition with the image of water-sensitive paper and other cards. The test results showed that: The evaluation method of 50% effective deposition amount was more suitable than the evaluation method of droplet density for evaluating the effective spraying width of plant protection UAV 3WQF120-12, which had a relatively larger droplets size, and the volume median diameter of droplet was about 270-380 μm. The average effective spraying width of plant protection UAV 3WQF120-12 was greater than or equal to 4.44 m with the evaluation method of 50% effective deposition amount. The evaluation method of droplet density was more suitable than the evaluation method of 50% effective deposition amount for evaluating the effective spraying width of plant protection UAV P-20, which had a re