温室穴盘苗多末端补苗移植机构设计与试验

Design and Test of Multi-end Seedling Transplantation Mechanism for Greenhouse Cave Tray Seedlings

摘要:

在温室穴盘育苗过程中，存在种苗漏播、长势不良等现象，为保证出厂苗品级，需要将这些劣苗的苗坨剔除并补栽健康钵苗。现有的取苗末端执行器主要适用于大苗龄钵体苗，对小苗龄、弱根系钵体苗适应性差，为此设计了一种适用小空间取植苗的柔性末端执行器及其成排多末端补苗作业机构。柔性末端执行器可单独控制，在取苗时爪片下降过程中逐步收拢，对苗坨形成渐进式夹紧作业。以一串红、石竹、四季海棠、矮牵牛穴盘苗为研究对象，对柔性取植末端执行器进行刚柔耦合动力学分析，开展柔性取植末端执行器的三因素三水平补苗移植正交试验。结果表明：影响苗坨完整度的试验因素由大到小为爪片间距、爪片宽度、基质含水率，确定最优参数组合为爪片间距21mm，爪片宽度18mm，基质含水率55%~60%。在最优参数组合下对穴盘苗进行末端执行器补苗移植性能验证试验，结果表明，钵苗移植成功后其苗坨完整度在85%以上，满足补苗移植作业需求，整机补苗效率为2105株/h（约为68盘/h），该研究可为温室穴盘育苗自动化补苗作业提供参考。

Abstract:

In the process of seedling raising in the greenhouse cavity tray, there are phenomena such as seedling leakage and poor growth. In order to ensure the grade of factory seedlings, it is necessary to remove these inferior seedling substrate blocks and replant them with healthy seedlings. The existing end effector for seedling extraction is mainly suitable for large-seedling-aged bowl-body seedlings, and has poor adaptability to small-seedling-aged and weak-rooting bowl-body seedlings. Therefore, a flexible end effector was designed, which suitable for small space seedling planting and its row of multi-end seedling replenishment operation mechanism. The flexible end-effector can be controlled separately, and the claw blades were gradually retracted during the seedling picking process during the descending process, forming a progressive clamping operation on the substrate block. A bunch of red, caryophyllus, begonia, and petunia burrow seedlings were taken as the research objects. Carry out the rigid-flexible coupling dynamic analysis of the flexible end effector for manipulators. The orthogonal experiment of three-factor and three-level seedling transplantation of flexible planting end effector was carried out. The results showed that the experimental factors affecting the seedling root ball intergrity were claw spacing, claw width and substrate moisture content, and the optimal parameter combination was 21mm for claw spacing, 18mm for claw width and 55%~60% for substrate moisture content. Under the optimal combination of parameters, the end-effector seedling transplantation performance verification test was carried out. The results showed that the integrity of the bowl body was more than 85% after successful transplantation, which met the needs of seedling transplantation, and the average seedling replenishment efficiency of the whole machine was 2105 plants/hour (about 68 trays/hour). The research result can provide a reference for the automatic seedling replenishment operation of greenhouse cavity tray seedlings.