基于EDEM-RecurDyn的指夹式取苗爪仿真优化与试验

Simulation Optimization and Experiment of Finger-clamping Seedling Picking Claw Based on EDEM-RecurDyn

为了实现自动移栽机高效、高质量取苗,提出整排取苗、同时投苗的工作方式。以指夹式取苗爪为研究对象,阐述了取苗爪的结构组成及工作原理。建立了取苗爪的运动数学模型,结合钵体力学特性及根系分布特点,对组成取苗爪的各构件进行尺寸参数优选,并在RecurDyn中建立其虚拟样机模型。通过试验进行钵体力学性能测量,对试验所得数据进行处理,得出钵体物理特性参数,进而在EDEM中建立钵体颗粒模型。通过EDEM-RecurDyn耦合仿真取苗爪插入、夹取、提离过程。分析取苗爪插入钵体苗深度、开始夹苗深度对取苗时钵体的影响,仿真优化得到当取苗爪插入钵体深度I_(d)=34 mm,插入钵体平均速度I_(v)=280 mm/s,开始夹苗深度C_(i)=4 mm,夹苗平均速度C_(v)=250 mm/s时,可以获得较好的钵体完整性。在16、20、24次/min的取苗速率下进行取苗爪取投苗试验,结果表明,所设计的指夹式取苗爪取苗成功率均在96%以上,钵体破碎率小于1%,具有良好的取苗、投苗效果,在取苗作业中可以保持良好的钵体完整性。

In order to achieve efficient and high-quality seedling picking by the automatic transplanter,one working method of picking seedlings in a row and throwing them at the same time was proposed.Taking the finger-clamping seedling picking claw as the research object,the structure and working principle of seedling picking claw were expounded.A mathematical model of the seeding picking claw movement was established,combined with the mechanical characteristics of the pot and the root distribution characteristics,the size parameters of the various structural parts that made up the claws were optimized,and the virtual prototype model was established in RecurDyn.The mechanical properties of the bowl were tested through experiments,the data obtained from the experiment were processed,and the physical characteristic parameters of the particles were obtained,and then the bowl particle model was established in EDEM.Through EDEM-RecurDyn coupling to simulate the process of inserting,clamping and lifting the seedling picking claws.The influence of claws insertion depth and initial clamping depth on the effect of bowl while picking was analyzed.Simulation optimization showed that when the insertion depth of the seedling claw I_(d)=34 mm,the average insertion velocity I_(v)=280 mm/s,the initial clamping depth C_(i)=4 mm,and the average clamping velocity C_(v)=250 mm/s,a better pot body integrity can be obtained.At 16 times/min,20 times/min,24 times/min,the claw picking test was carried out.The test showed that the finger-clamp claw picking success rate was above 96%,the pot body fragmentation rate was less than 1%,which had a good effect of picking and putting seedlings,which can maintain a good pot body integrity during seedling picking operations.