水稻机械除草避苗控制系统设计与试验  

Design and test of control system for rice mechanical weeding and seedling-avoiding control

作　　者：陈学深[1] 黄柱健 马旭[1] 齐龙[1] 方贵进 CHEN Xue-shen;HUANG Zhu-jian;MA Xu;QI Long;FANG Gui-jin(College of Engineering,South China Agricultural University,Guangzhou 510642,China)

机构地区：[1]华南农业大学工程学院,广州510642

出　　处：《吉林大学学报（工学版）》2021年第1期386-396,共11页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(51575195);广东省重点领域研发计划专项项目(2019B020221002);广东省杰出青年基金(2019B151502056);广州市科技计划项目(201803020021);现代农业产业技术体系建设专项资金项目(CARS-01-43)。

摘　　要：为使除草部件的作业路径能避开稻苗,降低机械除草的伤苗率,设计了一种机器视觉与液压伺服控制技术相结合的避苗控制系统。采用垂直俯拍方式,提取了稻苗冠层边界的形心图像坐标位置,通过小孔成像模型转换,获得稻苗地面坐标位置及除草部件中心与苗行中心线的距离。建立了平行四杆纠偏机构的液压控制系统模型,获得纠偏调控量与液压推杆的映射关系。基于PID控制算法,建立了比例阀液压系统数学模型,应用Matlab/Simulink仿真表明:模型的稳态响应时间约为0.28 s,静差约为0.07 mm。进行了台架试验,结果表明:图像处理系统提取苗行中心线误差不超过3 cm;正交试验结果表明:避苗控制系统中伤苗率的影响因素主次顺序为:行进速度、移栽天数、稻苗间距,当行进速度为0.8 m/s、移栽天数为10 d、稻苗株距为12 cm时,伤苗率为2.48%。To enable the weeding component to avoid the seedling on the operation path and reduce the seedling injury rate of machinery weeding,an automatic seedling avoidance control system based on machine vision and hydraulic servo control is proposed in this paper. First,by the way of overshoot,the centroid image coordinate position of the seedling canopy is extracted. Second,through pinhole imaging principle conversion,the seedling ground coordinate position and the distance between the weeding component and the center line of rice row are obtained. Third,a hydraulic control systems model of parallel four connecting rods of organizations is built,and the mapping relations between deviation control and hydraulic stem is acquired. Finally,based on PID algorithm,a proportional valve hydraulic system mathematical model is built. The Matlab/Simulink simulation shows that the model has a steady-state response time of 0.28 s and a static error of 0.07 mm. The results of bench test indicate that the error of the center line of the seedling belt extracted by the image processing system does not exceed 3 cm. The Orthogonal experiment indicates that the factors affecting the seedling injury rate in the avoiding plants control system are in the order of speed of travel,time of transplanting and spacing of plants. When the traveling speed is 0.8 m/s,the transplanting time is 10 days,and the intra-row distance of rice seedling is 12 cm,the seedling injury rate is 2.48%.

关 键 词：农业工程与信息技术 水稻 机械除草 避苗控制 PID算法 仿真分析 

分 类 号：S237[农业科学—农业机械化工程]