自走式移栽机行星轮转臂式栽植机构优化设计与试验

发布时间：2018-06-01 03:14

本文选题：自走式移栽机 + 行星轮转臂式栽植机构　；参考：《江苏大学》2017年硕士论文

【摘要】：栽植机构作为自走式移栽机的核心工作部件,是将穴盘苗植入土壤的直接作业部件,其性能直接影响着穴盘苗的栽植质量和移栽机的整机性能。本文在课题组对行星轮转臂式栽植机构的研究基础上,针对栽植直立度较低、适用株距单一、局限性较大等问题,结合适栽期蔬菜穴盘苗物理特性,建立栽植机构前后鸭嘴的运动学模型,开展了栽植机构运动轨迹、参数优化、虚拟样机及孔穴成型仿真、样机田间试验等研究工作,以改善行星轮转臂式栽植机构栽植性能,提高其适用性及通用性。本文的主要研究内容如下:(1)对适栽期蔬菜穴盘苗物理特性进行研究,对穴盘苗高度、叶冠直径、苗钵质量及钵体尺寸等参数进行测定,统计分析穴盘苗的几何尺寸及形态特性的分布区间,并以此为参考依据设计栽植鸭嘴结构形状及开合凸轮结构尺寸。(2)对自走式自动移栽机整机结构和栽植工作过程详细阐述,明确栽植机构的工作条件;对行星轮转臂式栽植机构结构组成及工作原理进行详细说明,设计栽植部件多行同步栽植方案和传动方案;对栽植部件各参数间关系进行详尽理论推导,确定栽植部件设计转臂数和传动比参数及三种对应设计株距280mm、310mm和345mm。(3)建立栽植机构前后栽植点的运动数学模型,提出栽植机构轨迹优化条件,基于MATLAB/GUI平台开发计算机辅助优化设计人机交互界面,对该界面各模块功能进行详细说明;基于该辅助优化设计界面,研究分析了各主要变量参数对前后栽植点运动轨迹的影响规律,对栽植机构各变量参数进行优化,基于各变量参数影响变化规律,由人机交互优化出一组满足优化要求的机构参数:L_1=83mm,L_2=22mm,L_3=38mm,L_4=145mm,R_d=120mm,a=82°,b=8°,C(105,-22),D(165,-17)。(4)根据优化后的机构参数对关键部件结构进行设计,利用Pro/E建立栽植机构的三维模型虚拟样机,将其导入ADAMS中进行虚拟样机运动仿真,得到植苗过程中苗钵与前后鸭嘴的相对位置,由仿真后处理得到机构运动轨迹和苗钵速度、加速度曲线,对比仿真结果与理论优化结果的差异,对栽植机构优化设计理论分析和结果的合理性进行验证;并对栽植孔穴成型过程及孔穴形状尺寸进行仿真研究。(5)试制栽植部件物理样机并装配至自走式移栽机样机上,进行栽植机构田间植苗试验,检验栽植机构理论分析可行性与实际作业性能;通过田间试验可以发现,实际栽植结果与理论分析结果基本一致,表明该机构运动建模和优化设计是正确可行的,优化设计的机构能满足移栽工作要求。
[Abstract]:As the core part of self-walking transplanting machine, planting mechanism is the direct working part of transplanting plantlets into soil, and its performance directly affects the planting quality of plantlets and the whole machine performance of transplanting machine. In this paper, based on the research of planetary rotation arm planting mechanism, aiming at the problems of low upright degree, single plant spacing and great limitation, this paper combines the physical characteristics of vegetable plantlets in suitable planting period. The kinematics model of duck beak before and after planting mechanism was established, and the research work such as motion track, parameter optimization, simulation of virtual prototype and hole forming, field experiment of prototype were carried out in order to improve the planting performance of planetary rotation arm type planting mechanism. Improve its applicability and versatility. The main contents of this paper are as follows: (1) the physical characteristics of vegetable poop seedlings at suitable stage were studied. The seedling height, the diameter of leaf crown, the quality of seedling bowl and the size of bowl were measured. The distribution interval of geometric size and morphological characteristics of plantlets are statistically analyzed, and the structure of self-walking automatic transplanting machine and the working process of planting are described in detail according to the structural shape of duckbill and the size of opening and closing cam. The working conditions of the planting mechanism are defined, the structure and working principle of the planetary rotation arm planting mechanism are explained in detail, and the multi-row synchronous planting scheme and transmission scheme of the planting parts are designed. The relationship between the parameters of planting components is deduced in detail, and the number of rotation arms and transmission ratio parameters of planting components and the three corresponding design plant spacing of 280 mm ~ 310mm and 345mm 路m ~ (3) are determined to establish the kinematic mathematical model of the planting points before and after planting mechanism. Based on the MATLAB/GUI platform, the human-computer interactive interface for computer-aided optimization design is developed, and the functions of each module of the interface are explained in detail. The influence of the main variable parameters on the track of the front and rear planting points is studied and the parameters of the planting mechanism are optimized. Based on human-computer interaction, a set of mechanism parameters: 1 / L _ 1 / 83mm / L _ _ _ It is introduced into ADAMS to simulate the motion of virtual prototyping, and the relative position of the seedling bowl and the front and rear duck beak in the process of seedling planting is obtained. After the simulation, the track of the mechanism, the velocity and acceleration curve of the seedling bowl are obtained. The differences between the simulation results and the theoretical optimization results are compared to verify the rationality of the theoretical analysis and the results of the optimal design of the planting mechanism. Simulation study on the forming process and the shape and size of the hole is also carried out. The physical prototype of the planting parts is manufactured and assembled into the prototype of the self-walking transplanting machine, and the field seedling planting experiment of the planting mechanism is carried out. The feasibility of theoretical analysis and practical performance of the planting mechanism were tested, and the results of field experiments showed that the actual planting results were basically consistent with the theoretical analysis results, which indicated that the kinematic modeling and optimal design of the mechanism were correct and feasible. The optimum design mechanism can meet the requirement of transplanting.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S223.9

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