甘薯裸苗膜上“船底形”机插位姿形成机理研究

Sweet potato slips are soft,tender and thin,and planting agronomy is also complex,which make it very difficult for the mechanical cultivation on mulched soil. Planting on mulched soil is the main cultivation mode for sweet potato slips in spring in northern China. The“boat”-shape planting method can bring high quantity and similar size for sweet potato.In order to realize mechanical planting on mulched soil for sweet potato slips, the research is carried out focusing on the three factors of slips, machine and soil that influence the “boat”-shape planting posture on mulched soil. Firstly,taking typical sweet potato varieties as study objects, the relationship is investigated between the damage intensity of slips, the mechanical action, variety and biological characteristics. The physical mechanical properties of soil are tested,and flexible model for slips and soil are constructed respectively.Secondly,plan the “boat”-shape transplanting path with NURBS, and design the bionic transplanting manipulator that can hold slips tightly and harmlessly.Using mathematical modeling and parametric experiments methods,motion envelope group of manipulator is analyzed to explore the inner impact factors of cavity shape and membrane hole morphology by studying the formation mechanism of transplanting path.Finally,set up slips-manipulator-soil system dynamics model, and analyze the movement posture and stress state of sweet potato slips in the process of mechanical transplanting.The interaction mechanism is revealed among the soil condition, slip size and manipulator movement effect on slips planting posture, and the manipulator test bench is optimized and set up. This project will create the theory and technical conditions for sweet potato slips transplanting mechanization on mulched soil.

甘薯裸苗“软、柔、细”的生物性状和复杂的栽插农艺，是造成甘薯膜上机械栽插难的主要原因。本项目针对北方春薯垄作覆膜的种植模式，选取结薯多、薯块匀的“船底形”栽插法，围绕影响薯苗膜上栽插位姿的苗、机、土三因素展开研究，系统解决甘薯膜上机械栽插难题。具体包括：以适栽期甘薯高剪苗为栽插对象，研究薯苗损伤强度与机械作用、品种及生物学特性的关系，测定土壤物理机械特性，构建薯苗、土壤柔性体模型；NURBS仿形规划“船底形”栽插路径，仿生设计薯苗栽插机械手，优化低损稳苗夹持结构，理论分析和试验研究机械手运动包络线群，探明栽插路径对穴形、膜孔形态影响的内在因素及形成机理；建立薯苗-机械手-土壤系统动力学模型，分析薯苗在机械手打穴栽插过程中的运动姿态和受力状态，揭示土壤条件、持苗姿态、薯苗大小、机械手运动对薯苗位姿的交互影响机理，优化构建机械手试验台架，为甘薯膜上移栽机械化创造理论和技术条件。

薯苗裸苗“软、柔、细”的生物性状和复杂的栽插农艺，是造成甘薯膜上机械栽插难的主要原因。本项目针对北方春薯垄作覆膜的种植模式，选取结薯多、薯块匀的“船底形”栽插法，围绕着影响薯苗膜上栽插位姿的苗、机、土三因素开展了研究。具体包括：以35天的龙薯9号、西瓜红、烟25、紫薯四种不同品种的甘薯高剪苗为研究对象，研究了薯苗的生物力学特性，测试了土壤物理机械特性，构建了薯苗的柔性体模型及土壤的离散元模型；调研了甘薯垄作覆膜栽植方式，模拟人手持苗“船底形”栽插动作，仿生设计了薯苗栽插机构，开展了实现“船底形”栽插轨迹的栽插机构参数化优化设计方法研究，通过仿真分析，探明了栽插机构参数对栽插轨迹、穴形、膜孔形态的内在影响。建立了薯苗-栽插机构-土壤耦合模型，通过协同仿真分析了薯苗在打穴栽插过程中的运动姿态形成机理，最后优化构建了栽插机构试验台架，开展了薯苗膜上栽插试验测试，为薯苗膜上移栽机械化创造了理论和技术条件。项目按照计划书开展了研究工作，项目执行期间发表相关高水平论文6篇，获得软件著作权2项，申请发明专利3项，授权实用新型专利2项。