【作者】 袁锐；

【导师】 马旭；

【作者基本信息】 吉林大学 ， 农业机械化工程， 2006， 博士

【摘要】 精密播种是一种先进的种植方法,是现代化农业的必经之路,也是农业增产增收和降低粮食生产成本的重要措施之一。多年来人们一直致力于精密播种机具的基础理论和整机试验研究。本文对种子触土后的弹跳滚动位移进行了深入、系统的研究,主要内容如下:首先进行了单圆盘开沟器和V形断面开沟器的种子触土后弹跳滚动位移试验研究,分别得到了种子触土后弹跳滚动位移模型,找出有利于减小种子弹跳滚动的开沟器所开沟形条件;接着进行了土壤性质对种子触土后弹跳滚动位移影响的试验研究,通过试验研究土壤粒度、土壤湿度等土壤性质及土壤在振动情况下对种子弹跳滚动位移的影响,建立种子位移与参数间的数学模型,利用控制土壤的粒度、施加振动力来控制种子触土后的弹跳滚动位移;然后建立了种子与土壤碰撞的离散元法计算模型,应用离散元软件分析种子触土过程,确定合理的分析计算参数,并进行仿真研究,揭示种子与土壤之间的作用规律;根据上述结果,研制出一种振动式开沟器,采用振动方法,借助采土槽板实现细土覆盖沟底,利用其所作用的土壤性质和所开沟形控制种子在沟内的弹跳滚动;最后应用Pro/E软件对精密播种机单体进行虚拟制造和运动仿真,提高了设计的准确性和效率。本文的研究为提高精密播种质量和丰富精密播种理论打下了一定的基础。更多还原

【Abstract】 The precision planting is an advanced planting method, a necessary way to achieve agricultural modernization and also an important step to increase crop yield, income, and decrease cost of grain production. The precision planting provides accurate placement of seeds to soil at equal interval within rows and seeding depth; it is a complicated process comprising of profile modeling, ditching, fertilizing, planting, covering and suppressing; the requirements of its field performance are quite strict; its design is difficult and cost of its trial-manufacture and field test is high. The presently used design mothod is repeated field tests and improvement. For a long time scientists have studied hard on fundamental theory of precision planting, but their researches focus on mainly whether seeds are given in an even space distribution, a simulation research of seeds distribution in field by Monte Carlo theory(statistic simulation method), and theoretical analysis of single component and practical experiment of whole machine. All of these researches studied little on the position change of the seed, the displacement of seed bouncing and rolling after its touching soil in analyzing seeds distribution in field using precision planting machine. JiLin University of Technology has studied and calculated the displacement of seed bouncing and rolling after it touching soil, but only analyzed the process in static view.This paper researched on displacement control of seed bouncing and rolling after it touching soil and design of furrow opener. After reviewing the research development of precision planting technology, design of furrow opener, and application computer simulation technology on farm machinery, the mathematical relation model of seed bouncing and rolling displacement after it touching soil influenced by ditch shapes and更多还原