【作者】 张旭；

【导师】 黄兴华；

【作者基本信息】 东北农业大学 ， 机械设计及理论， 2021， 硕士

【摘要】 针对当前烟草人工移栽为主半自动移栽机移栽为辅、移栽效率低的问题,为实现自动取苗作业,结合烟草移栽农艺要求,以钵盘育苗方式为研究对象,设计了一种非圆齿轮行星轮系取苗移栽机构,建立机构理论模型,基于计算机辅助优化设计软件平台利用Visual Basic6.0开发烟草钵苗取苗移栽机构优化设计程序,应用该程序对机构进行了多目标参数优化设计,得出一组满足烟草大株距移栽农艺要求的取苗移栽理论轨迹与移栽机构结构参数;利用Solidworks建立取苗移栽机构的三维模型,完成机构物理样机加工,开展机构运动学虚拟仿真分析、高速摄像台架试验和取苗移栽机构的台架性能试验,具体内容如下:(1)介绍了我国目前烟草种植现状以及国内外移栽机的研究现状,对比可知国外全自动移栽机械已经得到广泛应用,而国内仍然以手工移栽为主半自动机械移栽为辅,生产效率较低。(2)进行烟草钵苗物理力学特性试验。通过试验确定本文移栽机构的取苗方式和多因素试验中移栽频率的取值范围。(3)基于东北农业大学课题组研究建立的计算机辅助软件优化平台,开展多目标、多参数、耦合性强的全自动烟草移栽机的取苗栽植机构研究,优化移栽轨迹,得到移栽机构结构设计参数。(4)根据“夹取式烟草钵苗取苗栽植机构优化设计软件”输出的移栽机构结构参数,运用Auto CAD2017对移栽机构进行零部件的设计,然后运用solid work2018对其进行数字化模型建立以及装配,最后运用ADAMS 2017对移栽机构进行仿真分析,验证移栽机构设计的合理性与装配的准确性。(5)进行高速摄像台架试验。将高速摄像机拍摄到的移栽机构实际工作轨迹与计算机辅助软件优化出的轨迹以及仿真轨迹进行对比,验证物理样机加工以及装配的准确性。与此同时,借助PCC 2.8软件进行移栽机构运动学分析,验证移栽机构在实际工作中的可行性。(6)进行取苗移栽机构的台架性能试验。搭建试验台架,进行三因素五水平二次旋转正交组合优化试验,试验因素选取移栽频率、夹苗片长度以及钵苗高度,试验指标选取取苗成功率和伤苗率。利用软件Design-Expert V8.0.6进行参数优化,优化结果:当钵苗高度为170mm,移栽频率为40～45r/min,夹苗片长度为94～103mm时,移栽机构的取苗成功率大于90%,伤苗率小于5%。选取一组优化结果进行试验验证,试验获得移栽机构取苗成功率为91.67%,伤苗率为3.71%,满足移栽机构设计要求,验证了参数优化结果的准确性。更多还原

【Abstract】 Aiming at the current problem of manual transplanting of tobacco as the main and semi-automatic transplanting machine as auxiliary and low transplanting efficiency,in order to realize the automatic seedling removal operation,combined with the agronomic requirements of tobacco transplanting,the design of the pot seedling raising method is the research object.A non-circular gear planetary gear planting seedling transplanting mechanism is established and the theoretical model of the mechanism is established.Based on the computer-aided optimization design software platform,the optimization design program of the tobacco bowl seedling transplanting mechanism is developed using Visual Basic 6.0 and is applied to the mechanism.The multi-objective parameter optimization design of the mechanism was carried out with the program,and a set of theoretical track and structural parameters of seedling taking and transplanting mechanism meeting the agronomic requirements of tobacco large plant spacing transplanting were obtained.Use Solidworks to establish a three-dimensional model of the seedling transplanting mechanism,complete the processing of the physical prototype of the mechanism,carry out the virtual simulation analysis of mechanism kinematics,high-speed camera bench test,and the bench performance test of the seedling transplanting mechanism.The specific contents are as follows:(1)The present situation of tobacco planting in China and the research status of transplanting machine at home and abroad were introduced.By comparison,it can be seen that the automatic transplanting machine in foreign countries has been widely used,while in China,manual transplanting is still the main and semi-automatic transplanting machine is auxiliary,and the production efficiency is low.(2)The physical and mechanical properties of tobacco pot seedlings were tested.Through experiments to determine the transplanting mechanism of this text and the transplanting frequency value range in the multi-factor experiment.(3)Based on the computer-aided software optimization platform established by the research team of Northeast Agricultural University,the research on the seedling transplanting and planting mechanism of the multi-objective,multi-parameter,and strong coupling automatic tobacco transplanter is carried out,and the transplanting trajectory is optimized,and the structural parameters of the transplanting mechanism are obtained.(4)According to the structural parameters of the transplanting mechanism outputted by "Optimal Design Software of Plucking Tobacco Seedling Seedling from Potted Seedling",Auto CAD2017 was used to design the parts of the transplanting mechanism,and then Solid Work2018 was used to establish and assemble the digital model.Finally,the transplanting mechanism was simulated and analyzed by ADAMS 2017 to verify the reasonableness of the design and the accuracy of the assembly.(5)Carry out high-speed camera bench test.The actual working trajectory of the transplanting mechanism captured by the high-speed camera is compared with the trajectory optimized by the computer-aided software and the simulated trajectory to verify the accuracy of the physical prototype machining and assembly.At the same time,the kinematics analysis of the transplanting mechanism was carried out with the help of PCC 2.8 software to verify the feasibility of the transplanting mechanism in actual work.(6)Carry out the bench performance test of the seedling transplanting and transplanting mechanism.A test bench was set up to conduct a three-factor five-level two-rotation orthogonal combination optimization test.The test factors selected transplanting frequency,seedling clip length and pot seedling height,and test indicators were selected seedling success rate and seedling damage rate.Use the software Design-Expert V8.0.6 to optimize the parameters,and the optimization results: when the height of the pot seedling is 170 mm,the transplanting frequency is40～45r/min,and the length of the seedling clip is 94～103mm,the success rate of seedling removal of the transplanting mechanism More than 90%,the seedling damage rate is less than 5%.A set of optimized results was selected for experimental verification.The experiment showed that the transplanting mechanism had a success rate of 91.67% of seedling removal and a 3.71% damage rate,which met the design requirements of the transplanting mechanism and verified the accuracy of the parameter optimization results.更多还原