【作者】 黄小龙；

【导师】 李伟；

【作者基本信息】 中国农业大学 ， 机械设计及理论， 2014， 博士

【摘要】 株间锄草机器人是融合多传感器信息,应用机器视觉、自动化控制等技术进行机械式株间除草的农业智能装备。末端执行器是株间锄草机器人的关键部件,直接影响株间除草效果。本文以应用于蔬菜大田的末端执行器为研究对象,结合我国蔬菜大田种植模式,针对不同的土壤环境,采用优化设计方法为株间锄草机器人设计末端执行器,使除草作业效果最优,并对株间锄草机器人本体进行了设计与研究。论文主要研究内容如下：(1)研究了爪齿形末端执行器的优化设计方法。对爪齿形末端执行器结构与工作原理进行了研究,建立了爪齿的运动学模型并分析了影响爪齿运动轨迹的参数,进而建立了爪齿形末端执行器优化设计的数学模型,将覆盖率和入侵率代替除草率和伤苗率作为评价指标,获得了合理的结构参数。(2)研究了月牙形末端执行器锄刀结构参数的优化组合方法。建立了月牙形末端执行器锄刀的几何数学模型与运动学模型,选取锄刀的不同参数和水平进行正交试验,分析了锄刀直径、豁口夹角、刀刃切除距离、锄刀圆心与作物苗行中心线的偏距等因素对株间除草效果的影响,优化出最佳结构参数组合。(3)研究了月牙形末端执行器锄刀运动轨迹的优化方法。对月牙形末端执行器锄刀的运动轨迹进行了规划,建立了运动控制优化数学模型,并对锄刀的运动轨迹进行了仿真分析。(4)研究了月牙形末端执行器锄刀结构形状的优化方法。应用相对运动原理研究作物苗株中心相对锄刀旋转中心的运动轨迹线,建立作物苗株保护区沿运动轨迹线移动的数学模型,获取锄刀的最优结构形状,并根据株距变化设计了7个型号月牙形末端执行器,为选择最优型号的月牙形末端执行器进行株间除草作业提供了理论依据。(5)研究及设计了株间锄草机器人本体结构与液压系统,并进行了田间性能试验。试验结果表明设计的株间锄草机器人作业效果良好,株距均值为400mm时,除草率为96.2%,伤苗率1.4%：株距均值为350mm时,除草率为9.5.4%,伤苗率1.3%。更多还原

【Abstract】 The intra-row weeding robot is a mechanical weeding machine which is based on the technology of multi-sensor information,machine vision and automation control.The end-effector is the key component of the weeding robot which can influence directly the effect of weeding.This dissertation took the end-effector of intra-row weeding robot as the research object,studied the optimal design methods of the end-effector to achieve the best effect of weeding according to the different soil situation and vegetable planting pattern in our country,developed intra-row weeding robot mechanism.The main contents are as follows:(1) Method of optimal design and research on the end-effector with claw tooth was studied. A new evaluation index of the coverage rate and inbreaking rate is proposed instead of the weeding rate and wounded seedling rate.The structure and working principle were introduced,and the optimum structure parameters were given out through the analysis of the trajectory of the claw tooth by the established kinematics model.(2) Method of optimization combination of the structure parameters for the rotating disc of the crescent end-effector was researched.The geometry model and kinematic model were established for the rotating disc.Then the virtual orthogonal experiment was done in different factors and different levels.In order to obtain the best structure parameters in combination,the effects of weeding performances of the rotating disc in diverse parameters were analyzed.(3) Method to control the rotation speed of the rotating disc was studied for a better operation effectiveness.The trajectory of the rotating disc was designed by controlling the rotation speed,and an optimization analysis was done by simulating its working process.(4)Method to design the optimum structure shape of the rotating disc was proposed.On the basis of the relative motion theory,the trajectory of the plant was analyzed relative to the rotating disc of the crescent end-effector,and an optimization model was established to obtain the optimum structure shape, which provided a theoretical basis for design.Then7kinds of the rotating disc were designed to fit the different plant spacing.(5)The intra-row weeding robot mechanism and hydraulic system were developed,and field performance tests were conduced.The results showed that the prototype worked with a good operation effectiveness,and the weeding rate reached to96.2%,the wounded seedling rate was1.4%with the plant spacing of400mm.When the plant spacing was300mm, the weeding rate was95.4%and the wounded seedling rate was1.3%.更多还原