Jiang Shijie, Chen Bingtai, Li Wenwei, Yang Shenghui, Zheng Yongjun, Liu Xingxing
College of Engineering, China Agricultural University, Beijing, China.
Yan Tai Institute, China Agricultural University, Yan Tai, China.
Front Plant Sci. 2022 Oct 31;13:1040808. doi: 10.3389/fpls.2022.1040808. eCollection 2022.
For orchard plant protection, conventional large machines and small sprayers are practically restricted by either narrow planting intervals with dense leaves or their inadequate penetration power, which leads to an unsatisfactory effect of spray. This paper proposes a stereoscopic plant-protection strategy that integrates unmanned air and ground sprayers to spray different parts of canopies to improve uniformity. In order to verify the proposal, a stereoscopic plant-protection system (SPS) was developed, consisting of a small swing-arm sprayer and a T16 plant-protection Unmanned Aerial Vehicle (UAV). Then, optimal operation parameters were determined by Computational Fluid Dynamics (CFD) and orthogonal experiments, and the uniformity was finally quantified by trials. CFD and orthogonal experiments showed that a swing-arm angle of 60° and a forward speed of 0.4 m/s were optimal for the ground sprayer, whilst a height of 2.0 m from the top of canopies and a forward speed of 1.0 m/s were appropriate for the UAV. The trial results showed that the density of vertical droplet deposition varied from 90 to 107 deposits/cm in canopies, and the uniformity was 38.3% higher than conventional approaches. The uniformity of top, bottom, inside and outside canopies was significantly improved. Meanwhile, the density of droplet deposition on both sides of leaves in all test points exceeded 25 deposits/cm, able to meet the standard of spray. This study provides a practical approach for uniform pesticide spray to large-canopy fruit trees. Moreover, the high flexibility of plant-protection UAVs and the significant trafficability of small swing-arm sprayers can solve the problem of large machine entering and leaving orchards.
对于果园植保而言，传统大型机械和小型喷雾器实际上受到种植间距窄、叶片茂密或穿透能力不足的限制，导致喷雾效果不尽人意。本文提出一种立体植保策略，将无人空中和地面喷雾器相结合，对树冠不同部位进行喷雾，以提高均匀性。为验证该方案，开发了一种立体植保系统（SPS），由小型摆臂喷雾器和T16植保无人机（UAV）组成。然后，通过计算流体动力学（CFD）和正交试验确定了最佳运行参数，最终通过试验对均匀性进行了量化。CFD和正交试验表明，地面喷雾器的最佳摆臂角度为60°，前进速度为0.4 m/s，而无人机距树冠顶部高度为2.0 m，前进速度为1.0 m/s为宜。试验结果表明，树冠内垂直雾滴沉积密度在90～107个/cm之间，均匀性比传统方法提高了38.3%。树冠顶部、底部、内部和外部的均匀性均得到显著改善。同时，所有测试点叶片两侧的雾滴沉积密度均超过25个/cm，能够满足喷雾标准。本研究为大型树冠果树的农药均匀喷雾提供了一种实用方法。此外，植保无人机的高灵活性和小型摆臂喷雾器的显著通行能力可以解决大型机械进出果园的问题。
