小株距高密度蔬菜植苗机构设计与试验

Design and Experiment of Transplanting Mechanism for High Density Vegetables with Small Plant Spacing

针对现有植苗机构用于小株距蔬菜移栽时出现的轨迹不合理、穴口太大及秧苗直立性差等问题,提出一种适用于蔬菜小株距高密度移栽的史蒂芬森(Stephenson)型六连杆植苗机构。首先,建立史蒂芬森型六连杆植苗机构运动学模型,基于Visual Basic 6.0开发植苗机构辅助分析优化设计软件,分析了不同机构参数对植苗轨迹姿态的影响,并通过优化人机交互的方式得到一组满意的机构参数;其次,对植苗机构进行结构设计,三维建模并进行虚拟样机仿真,搭建试验台并进行空转试验得到实际植苗轨迹,将理论轨迹、虚拟仿真轨迹和实际植苗轨迹进行对比,三者轨迹基本一致,验证了该植苗机构设计的合理性。最后开展了植苗试验,在转速20~40 r/min下进行植苗试验时,植苗平均合格率91.7%,移栽后钵苗株距控制在110 mm左右,直立度接近于90°,满足小株距高密度移栽要求,验证了植苗机构具有较好的可行性和实用性。

Aiming at the problems of unreasonable trajectory,too large hole and poor uprightness of seedlings when the existing seedling planting mechanism is used for transplanting vegetables with small plant spacing,a Stephenson six-bar seedling planting mechanism suitable for transplanting vegetables with small plant spacing and high density was proposed.Firstly,the kinematics model of Stephenson six-bar seedling planting mechanism was established.Based on Visual Basic 6.0,the auxiliary analysis and optimization design software of seedling planting mechanism was developed.The influence of different mechanism parameters on seedling trajectory attitude was analyzed,and a set of satisfactory mechanism parameters were obtained by optimizing human-computer interaction.Secondly,the structural design of the seedling planting mechanism was carried out.The three-dimensional modeling and virtual prototype simulation were carried out.The test bench was built and the idle test was carried out to obtain the actual seedling planting trajectory.The theoretical trajectory,virtual simulation trajectory and actual seedling planting trajectory were compared.The three trajectories were basically the same,which verified the rationality of the design of the seedling planting mechanism.Finally,the seedling planting test was carried out.When the seedling planting test was carried out at different speeds of 20~40 r/min,the average qualified rate of seedling planting was 91.7%.After transplanting,the seedling spacing was controlled at about 110 mm,and the verticality was close to 90°,which met the requirements of small spacing and high density transplanting,and verified that the seedling planting mechanism had good feasibility and practicability.