基于苗钵—根系综合分析的取苗末端执行器设计及育苗工艺优化

发布时间：2018-04-23 08:55

本文选题：Micro-CT + 苗钵-根系　；参考：《江苏大学》2017年硕士论文

【摘要】：随着工厂化育苗和穴盘育苗的推广,我国加强了对移栽机械的关注,但是目前国内还没有投用于生产的全自动蔬菜移栽机,限制其发展的主要问题是已有的移栽机械缺少与穴盘苗的适应性、取苗爪与苗钵作用机理不清,机构设计与育苗工艺不相符合。对于这个问题,本文对穴盘苗苗钵的根系结构、力学特性、生长特性、取苗质量等方面进行研究,优化了取苗末端执行器和育苗工艺。主要研究内容概括如下:(1)以番茄穴盘苗为研究对象,探索苗钵和根系三维重建的方法、测量并验证番茄穴盘苗结构参数。试验得到适合番茄穴盘苗的Micro-CT扫描参数为扫描电压、扫描电流、扫描体素分别为55 kVp,72μA,45μm;根系模型空间位置最大、最小相对误差分别为12.105%、4.419%,根长度和根角度的平均相对误差分别为3.68%、5.56%;根系主要参数根体积、主根长度、根基部直径的相对误差分别为3.85%、3.34%、3.05%,对两独立样本进行t检验(α=0.05),根体积、主根长度、根基部直径的p值均大于显著性水平0.05,即CT模型根体积、主根长度、根基部直径和实测苗钵根体积、主根长度、根基部直径平均值无显著差异;因此,Micro-CT重建的穴盘苗钵体模型和根系模型在空间位置、参数测量方面均可靠。(2)基于CT根系模型,探索穴盘苗根系空间分布规律,分析不同育苗参数下苗钵的根系分布特点。试验结果显示:根体积、根分层密度在垂直方向上的分布呈现二次抛物线规律;在水平方向上,根系体积呈现二次抛物线的趋势,而根系分层密度是四次多项式分布规律;运用正交试验分析基质配比(草炭、蛭石和珍珠岩的体积比)、压实度(基质填充体积:穴盘体积)、施肥次数对穴盘苗根系垂直方向分布特点、水平方向分布特点、苗钵力学特性等的影响,综合考虑穴盘苗根系垂直方向分布特点、水平方向分布特点、苗钵力学特性等指标,发现适合夹取的穴盘苗培育方案是:基质配比为草炭:蛭石:珍珠岩为3:1:1,施肥次数为3次,压实度为1。(3)基于番茄穴盘苗根系空间分布、力学特性等因素进行取苗末端执行器设计和优化。根据取苗机构的工作原理、根系分布对夹取参数的影响,确定了边入边夹的取苗方式;综合考虑取苗末端执行器的结构特点、番茄穴盘苗的根系空间分布特点、苗钵拉拔力F与钵体夹持变形量的关系,对取苗末端执行器的结构参数进行优化。(4)基于穴盘苗根系空间分布、力学特性、生长质量和取苗质量的育苗工艺优化。分别在不同有效积温下,按照以基质配比、压实度、施肥次数为因素的正交试验培育穴盘苗,对苗钵生长质量和取苗质量进行统计分析,结果显示:在有效积温为707.82℃时,穴盘苗壮苗指数最大、取苗质量最好;针对有效积温为707.82℃时的穴盘苗,对不同育苗参数下的穴盘苗进行多指标(根系空间分布、力学特性、壮苗指数和取苗成功率)综合评分,确定了兼顾移栽性能和苗钵质量的最佳育苗参数为A3 C3 B1(草炭:蛭石:珍珠岩=3:1:1,施肥次数3次,压实度为1)。
[Abstract]:With the popularization of plant seedling raising and seedling raising, our country has strengthened the attention to transplanting machinery, but at present, the automatic vegetable transplanter has not been put into production in China. The main problem that restricts its development is the lack of adaptability of the existing transplanting machinery to the hole plate seedlings, the mechanism of taking seedling claws and seedling pots is not clear, and the mechanism design and seedling raising are made. For this problem, this paper studies the root structure, mechanical properties, growth characteristics, and seedling quality of the seedling bowl of the acupoint seedlings. The main research contents are as follows: (1) the method of three dimensional reconstruction of the seedling bowl and root system was explored, and the method of measuring the three dimensional reconstruction of the seedling bowl and root system was explored. The Micro-CT scanning voltage, scanning current and scanning voxel were 55 kVp, 72 A and 45 m respectively, and the space position of root model was the largest, the minimum relative error was 12.105%, 4.419%, and the average relative error of root length and root angle was 3.68%, 5.56, respectively, 5.56. The relative errors of root volume, main root length and base diameter were 3.85%, 3.34%, 3.05%, respectively, and t test (alpha =0.05) for two independent samples. The root volume, the length of the root and the base diameter were all greater than that of the significant level 0.05, that is, the root volume of the CT model, the root length, the base diameter and the measured root length, and the length of the main root. There was no significant difference between the average diameter and the average diameter of the base. Therefore, the Micro-CT rebuilt model and the root model were all reliable in the space position and the parameter measurement. (2) based on the CT root model, the spatial distribution of the root system of the acupoint seedlings was explored and the root distribution characteristics of the seedlings were analyzed under different seedling parameters. The experimental results showed that the root volume and root were the root volume. The distribution of the stratified density in the vertical direction presents two parabolic laws. In the horizontal direction, the root volume presents the two parabola trend, and the root layer density is the four polynomial distribution law; the orthogonal test is used to analyze the matrix ratio (the volume ratio of the peat, vermiculite and perlite), and the degree of compaction (the volume of the matrix filling: the volume of the cavern). The effect of fertilization times on the vertical distribution of the root system, the distribution characteristics of the horizontal direction, the mechanical properties of the seedling bowl, and the characteristics of the vertical distribution of the root system, the horizontal direction distribution and the mechanical properties of the seedling bowl were taken into consideration, and the cultivation scheme of the acupoint seedlings suitable for the clip was found that the matrix ratio was the Peat: vermiculite: Pearl The number of fertilizer was 3:1:1, the number of fertilization was 3 times, the degree of compaction was 1. (3) based on the spatial distribution of root system of tomato seedlings, and the design and optimization of the end actuator were taken. According to the working principle of the seedling mechanism, the effect of the root distribution on the clip parameters, the method of taking the seedlings of the edge clip was determined, and the end actuator of the seedling was taken into consideration. The structure characteristics, the spatial distribution characteristics of the root system of tomato seedlings, the relationship between the pulling force F of the seedling bowl and the deformation of the bowl body, optimize the structure parameters of the end effector of the seedling. (4) optimize the nursery technology based on the spatial distribution of the root system, the mechanical properties, the growth quality and the quality of the seedlings. The growth quality and seedling quality of the seedling bowl were statistically analyzed by orthogonal test of matrix ratio, degree of compaction and number of fertilizing times. The results showed that when the effective accumulated temperature was 707.82, the index of the seedlings was the largest and the quality of the seedlings was the best. The multiple indexes (root space distribution, mechanical properties, seedling index and seedling success rate) were evaluated synthetically, and the optimum breeding parameters of the seedlings were A3 C3 B1 (peat: vermiculite: Perlite =3:1:1, 3 times of fertilization and 1 compactness).

【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

【参考文献】