丘陵山地柑橘果园多方位自动喷药装置研制

Development of multi-orientation automatic spraying device for citrus orchards in hilly and mountainous areas

针对现有自动喷药装置对丘陵山地不同树冠大小的柑橘果树适应性差的问题,该文设计了一种双向多方位自动喷药装置。通过模式转换机构,实现竖直喷药模式、45°倾斜喷药模式和对地喷药模式的任意切换,以满足喷药装置对不同大小柑橘树的适应性需求,提高农药的利用率。采用自动对靶模块检测果树冠层高度和高压雾化喷头组件至冠层表面距离;采用车速测定模块实时检测履带式手扶拖拉机行进速度。室内试验结果表明:在3种喷药工作模式下,装置射程与喷幅均符合植保机械作业质量要求;单次喷药量为72～190 L/hm2,符合低剂量喷药要求;超声波传感器布置在喷杆前方0.8 m处,当履带式手扶拖拉机行驶速度3～8 km/h时,有效降低了信号检测与处理滞后带来的对靶误差,对靶精度为99.7%,符合设计要求。田间试验结果表明:在竖直喷药模式和45°喷药模式下进行喷药工作,柑橘树冠层表面雾滴平均覆盖率分别为82.5%和78.7%,沉积密度分别为109滴/cm2和106滴/cm2;冠层内部雾滴平均覆盖率分别为16.1%和30.6%,沉积密度分别为35滴/cm2和64滴/cm2,喷药效果满足国家标准要求。

In view of the poor adaptability of the existing automatic spraying device to citrus fruit trees with different crown size in hilly and mountainous areas,a bidirectional multi-mode automatic spraying device was development in this paper.The device was mainly composed of mechanical framework,high-pressure atomizing mechanism,air supply mechanism and automatic control system(which including power supply module,communication module,automatic target module,vehicle speed measurement module,motor drive module and solenoid valve).Changing the angle of spraying rod through the mode conversion mechanism,the vertical spraying mode,the 45°tilt spraying mode and the ground spraying mode were realized,which satisfied the adaptability requirements of the spraying device for citrus fruit trees of different sizes,and effectively improved the utilization of pesticides.Firstly,the canopy height of the fruit trees and the distance from the high pressure atomizing nozzle assembly to the crown surface were detected by the automatic target module composing of an ultrasonic sensor and a laser diode array,The ultrasonic sensor was responsible for detecting the top and bottom layers of the canopy,and guided the position adjustment of spraying rod and the on-off of solenoid value,so that the spraying rod could spray against the canopy;the laser diode array was responsible for detecting the distance between the spraying rod and the fruit trees,and guided the boom to adjust to the setting position.Secondly,the speed measuring module was used to detect the moving speed of the crawler-type walking tractors in real time.Thirdly,the collected datas were processed by the controller.The effects of the detection delay on the effect of the spraying were reduced by the cooperation of each module.The laboratory test results showed that the spray range and spray width of the device in 3 spray modes were in line with the quality requirements of plant protection machinery.The spray amount for one operation was 72-190 L/hm^2,which met the requirements of the low dose spray.The ultrasonic sensor was arranged at 0.8m in front of the spraying rod,when the working speed of the crawler-type tractor was not more than 8 km/h,it effectively reduced the target error caused by the delay of signal detection and processing,and the target precision was 99.7%,which was in line with the design requirements.Orthogonal experimental design method was used in field experiments,the effects of vehicle speed,air supply intensity and sprinkler-to-canopy distance on spraying efficiency were investigated by establishing L9(34)orthogonal experimental design table.The results of spraying in vertical spraying mode and 45°tilt spraying mode showed that the average droplet coverage on the canopy surface was 82.5%and 78.7%,respectively,and the droplet deposition density was 109 and 106 droplets/cm^2,respectively;the average droplet coverage in the canopy was 16.1%and 30.6%,respectively,and the droplet deposition density was 35 and 64 droplets/cm^2,respectively.The spraying effects met the requirements of national standards.