水培生菜整株低损收获装置设计与试验

Design and Test of Harvester for Whole Hydroponic Lettuce with Low Damage

摘要:

为解决水培生菜收获品质低、人工收获劳动力成本高等问题，设计了一种整株低损收获装置。通过夹持杆对菜叶的低损聚拢、割刀对生菜茎部的精准切割，实现单株水培生菜的整株低损收获。设计了各关键部件结构参数，分析了影响菜叶损伤的因素，利用图像处理方法测量了菜叶损伤面积；采用正交试验，研究了聚拢速度、聚拢角、聚拢高度、压菜速度对菜叶损伤面积的影响；通过力学分析和高速摄影，分析了聚拢角、聚拢高度对菜叶损伤面积的影响。正交试验结果显示：试验因素的显著性主次顺序为聚拢角、聚拢高度、压菜速度、聚拢速度；最优组合参数为聚拢速度100mm/s、聚拢角15°、聚拢高度70mm、压菜速度100mm/s。验证试验表明：最优组合下生菜均为整株收获，菜叶损伤面积平均值为432mm2，损伤程度平均值为0.13%，优化效果明显。

Abstract:

In order to solve the issues of hydroponic lettuce manual harvesting with low quality but high cost, a harvester was designed and manufactured. The leaves lying on the hydroponics planting board were gathered by the holding rods before cutting the stem. The key components of the harvester were calculated; for instance, the device of gathering leaves up, the cutter bar and conveyer device. The damage area was measured by using image processing method. The factors those would influence the leaf damage were generalized. The influence of gathering angle and gathering height on damage area was analyzed though the mechanical analysis and highspeed photography. Orthogonal test was utilized to study the influence of gathering velocity, gathering angle, gathering height and velocity of putting lettuce down on damage area. The results showed that the order of significance was gathering angle, gathering height, velocity of putting lettuce down and gathering velocity. The optimized combination of factors that gave the minimum damage area was obtained, and the value of gathering velocity, gathering angle, gathering height and velocity of putting lettuce down were 100mm/s, 15°, 70mm and 100mm/s, respectively. The average value of damage area was 432mm2, and the average value of damage degree was 0.13%, which meant that the optimization was obvious. This research offered a reference for designing the harvester which would harvest more than one hydroponic lettuce.