丘陵果园自走式小型靶标跟随喷雾机设计与试验

针对丘陵果园传统大型施药装备入园难、施药劳动强度大、作业效率低及药液浪费严重等问题,根据丘陵果园农艺特点和病虫害防治需求,设计一种丘陵果园自走式小型靶标跟随喷雾机,可配合植保无人机作业,提升果树冠层药液覆盖效果。喷雾机上集成靶标探测追踪系统与自主导航系统,靶标跟随喷雾机构采用双喷头联动式设计,喷雾角度与高度的调节范围根据雾滴运动规律进行确定,实现了果园植保自主作业。果园试验结果表明,对靶喷雾时果树冠层不同高度叶片正面的平均雾滴沉积个数变异系数为34.22%,同一高度不同采样点叶片正面的平均雾滴沉积个数变异系数为34.56%,相比于非对靶喷雾,喷施用水量、地面流失量与冠后飘移流失量分别降低26.70%、84.93%和53.50%,在减少药液浪费的同时,有效提高了果树冠层中下部叶片正面的雾滴分布均匀性。

Design and Experiment of Self-propelled Small Target Following Sprayer for Hilly Orchard

Conventional large-scale ground sprayers may hardly be deployed in hilly orchards due to the restriction of geo-characteristics, so that manual spray has to be a general approach for plant protection, which results in high labour intensity, low operational efficiency and severe chemical waste. A small self-propelled target-following sprayer for hilly orchards was proposed, which can work together with plant protection UAV. Two coupled nozzles were adopted for the target-following spray mechanism, and the ranges of their spray angle and height were calculated based on the developed physical motion model of droplets. Meanwhile, the method of target detection and tracking and the method of autonomous navigation were integrated into the proposed sprayer to realise autonomous operation. The verification experiment was performed in the apple orchard of Fuyu Forest Fruit Company in Hebei Province, and the results showed that the average coefficient of variation of droplet number deposited on the frontal surfaces of the leaves at different heights of canopies was 34.22%, while that at different sampling points at the same height was 34.56%. Compared with non-target spraying, the target-following spraying could effectively improve the uniformity of droplet distribution on the frontal surfaces of leaves both at different heights and at different internal and external positions of canopies. Besides, water consumption, ground loss and post-canopy drift loss could be reduced by 26.70%, 84.93% and 53.50%, respectively, which indicated that the proposed method can be a technical reference for the development and improvement of hilly orchard sprayers.