中文摘要：

为提高果园喷雾机自动化与精准喷雾作业性能,设计了一种基于变风量与变喷雾量的果园自动仿形喷雾机,喷雾系统以冠层分割模型作为变量处方,采用扫描精度高的激光传感器作为探测源,以电磁阀和无刷直流风机为执行元件,通过探测果树冠层体积调节电机和电磁阀的脉宽调制（pulse width modulation,PWM）信号以实时调节风机转速和喷头流量。设计了可独立调节风量和喷雾量的雾化单元,通过各个独立风机产生的高速气流协助雾滴穿透冠层;喷雾机最大作业高度4.2 m。田间试验结果表明,在行株距为5 m×2 m的单株苹果树左右两侧平均沉积量分别为1.92和1.37 u L/cm2,最少雾滴数为46.2个/cm2,大于常用方法对风送喷雾中雾滴喷幅界定的20个/cm2;树冠轮廓与沉积量和风速变化拟合结果显示,设计的喷雾机能够根据树冠信息实现仿形变量施药。该研究为果树病虫害防治提供新方法与新装备,为精准植保机具的结构设计和性能优化提供理论与方法参考。

英文摘要：

In order to improve the automatic working performance of orchard sprayer, in this study, an automatically variable-rate orchard sprayer with 40 nozzles and 8 fans based on LIDAR（Light Detection and Ranging） was developed. The high-precision scanning laser sensor was adopted as the detecting source to detecting the canopy parameter. Electromagnetic valve and brushless fan were adopted as actuators to control the flow rate and air volume based on the pulse width modulation（PWM）signals. Each nozzle in the spray system, coupled with a solenoid, achieved variable rate delivery in real time based on the canopy volume. Each side of the prototype equipped four integrated atomization units with one independent brushless fan. The independent brushless fan located behind of atomization unit, and assisted the droplets sprayed from the five nozzles blowing into the canopy, which is conductive to the local regulation of spraying quantity. The brushless motor has the advantages of fast-response, high-speed, and long working-time. The rotating speed of each brushless motor could be adjusted in real-time by PWM signal according to the canopy parameters of fruit tree. The canopy segmentation model was designed to measure the volume and density of canopy, which could meet 3 m height canopy. The canopy was divided into many canopy units, and each nozzle corresponded with one canopy unit and each brushless fan corresponded with five canopy units. A laptop was used to calculate the volume and density of each canopy unit based on the data scanned by laser sensor and the segmentation model. Then the spraying quantity needed forcanopy unit and the air volume needed for five canopy units were acquired by control system. Next, the PWM signals emitted by single chip microcomputer would be transmitted to the drivers of valves and fans to adjust the flow rate and air flow. A total of 48 channel PWM signals were designed for the whole machine, and each channel would be controlled separately. The gasoline generator was adopted as energy