多目标约束下液态肥精准穴深施及喷肥针-液态肥-土壤多介质互馈机理研究

The interaction effect between spray fertilizer needle and soil is the key factor that affects the operation efficiency of deep-fertilization mechanism when the machine is in operation. Aiming at the problems of strong coupling, non-linearity and fuzziness of multi-objective of the fertilizer spraying needle, and the soil adhesion of the fertilizer spraying needle in the process of non-linear movement, a high speed precision fixed-point mode of operation and coupled analysis theory of multiphase medium were came up in the research. The vertical linear trajectory and fixed-point posture of the “variable speed” spraying needle during the process of inserting and pulling out of the soil are gong to be studied, and a mathematical model of the needle to achieve precise fixed-point moving target need to be constructed, so as to solve the multi-parameter and multi-objective constrained optimization problem of spraying needle. Using the nonlinear dynamic method quantitative to describe the feedback coupling mechanism among the spray fertilizer needle, high-pressure spray and the soil on ANSYS, and then establish the coupling model about them, to reveal the dynamic relationship and mechanical behavior between injection surface and soil-wetting contact interface reveal . To further explore the law of the interaction of multi-media and multi-parameters on the soil adhesion, and finally solve the problem of soil adhesion of the fertilizer spraying needle. The implementation of this project can not only solve the problem of precise fixed-point fertilization, mprove fertilizer utilization rate, but also provide important theoretical basis and research basis for the interdisciplinary of machinery-fluid-soil cross-fusion, which has high academic value and scientific significance.

液态肥穴深施作业时，喷肥针与土壤的相互作用效果是影响深施机构作业效率的关键因素。针对非线性运动的喷肥针在入、出土过程中优化分析时，多目标存在强耦合性、非线性和模糊性以及针体粘土问题，提出了多约束下的高速精准穴深施肥实现机理及其多相介质耦合解析理论。研究“变转速”喷肥针在入、出土过程中实现垂直姿态和直线轨迹方法，构建针体达到精准定点运动目标的数学模型，解决喷肥针多参数与多目标约束优化问题；应用非线性动力学分析方法定量描述喷肥针—高压肥料射流—土壤相互作用机理，建立针体—肥料—土壤的互馈耦合模型，揭示喷肥针体表和土壤润湿接触界面动态关系和力学行为，进一步探明多介质多参数交互变化对粘附特性的影响规律，解决喷肥针粘附土壤问题。本项目的实施不仅可以解决精准定点施肥问题，提高肥料利用率，也可以为机械—流体—土壤多学科交叉融合提供重要理论基础和研究依据，具有较高的学术价值和科学意义。

为持续推进化肥农药减量，加快现代农业绿色发展，提高肥料利用率，增加作物产量与品质。本项目以高速精准穴深施肥为研究导向，针对非线性运动的喷肥针在入、出土过程中优化分析时，多目标存在强耦合性、非线性和模糊性以及针体与土壤耦合力学机理不明确问题，开展相关研究工作。主要研究内容与重要结果包括：①构建了精准定点深施机构设计理论模型，分析了机构运动学特性，实现定点扎穴要求。②利用ANSYS/LS—DYNA显示动力学软件，构建喷肥针—土壤耦合有限元模型，获取针体所受阻力变化规律。③提出液肥靶向深施实现方法，开发对靶点施控制系统，满足液肥靶向深施功能。④进行了台架与田间试验，台架试验结果表明扎穴针体实际作业轨迹与理论、仿真获取轨迹一致，在入、出土过程中，实际作业受力与仿真受力规律变化曲线一致，机构设计准确，性能优越。田间试验结果表明在作业速度为0.4~1.0m/s时，平均回土深度52.8mm，平均对靶率84.03%，装置回土性能和对靶喷肥性能稳定，满足液肥深施农艺要求。本项目研究内容、方法与结果可为提升我国液肥深施机具的高效化、精准化及智能化提供重要理论支撑和技术保障，同时可为部件-土壤多元耦合仿生、机-电-液多系统耦合、智能农业机械设计等领域研究提供方法参考和借鉴，促进多学科交叉融合，夯实理论基础和研究依据，具有重要的科学意义与实际应用价值。. 项目研究成果在国内外本领域期刊上发表SCI/EI论文4篇；申请发明专利1项，授权发明专利1项，授权实用新型专利1项；获得软件著作权2件；培养在读硕士生2名。