X-ray computerized tomography for characterization of pick-up destruction and pick-up parameter optimization of tomato root lumps
X-ray computerized tomography for characterization of pick-up destruction and pick-up parameter optimization of tomato root lumps
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DOI：
10.5424/sjar/2019172-13886
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发表时间：
2019-01-01
影响因子：
0.9
通讯作者：
Li, Yaxiong
中科院分区：
文献类型：
--
作者：
Mao, Hanping;Liu, Yang;Li, Yaxiong
本研究旨在利用X射线微计算机断层扫描技术，寻找番茄根块拾取破坏的原因，并确定低位根块破坏的拾取参数。对根系和孔隙进行了三维重建和定量分析。结果表明，根系的作用是缠绕和包裹根团，从而防止基质松动。根块破坏的主要原因是气孔聚集和裂纹的形成。挑针的顶端和周边分别是根块容易断裂和破损的区域。以这两个区域的空隙度作为衡量根块破坏程度的指标。以挑根针形状（圆形、扁平）、直径（2、2. 5、3 mm）和初始挑根角度（18 °、21 °、24 °）为试验因素，进行单因素方差分析，研究这3个因素对根块破坏的影响。结果表明，断裂区和易断区的孔隙度均随拾取针直径的增大而增大，随初始拾取角的增大而减小。在相同的拾取条件下，使用扁销的空隙率总是超过圆形销。当采用直径为2mm的圆形挑杆和初始挑杆角度为24 °时，根块的破坏率（6.63%）小于其他试验条件。优化后的夹持参数可用于指导夹持器的设计，提高自动移栽机的工作性能。
This study was aimed to find the causes of pick-up destruction of tomato root lumps using X-ray microcomputed tomography, and to identify the pick-up parameters of low root lump destruction. The roots and pores were reconstructed three-dimensionally and analyzed quantitatively. It was found that the roots acted winding and wraping the root lumps and thus preventing the substrate from loosening. The major causes for root lump destruction were pore aggregation and crack formation. The apex and circumference of pick-up pins were areas where root lumps were prone to fracture and breakage, respectively. Lacunarities of these two areas were used as index to quantify the root lump destruction. Single-factor analysis of variance was conducted with pick-up pin shape (circular, flat), diameter (2, 2.5, 3 mm) and initial pick-up angle (18 degrees, 21 degrees, 24 degrees) as the test factors and then the effects of these three factors on root lump destruction were studied. It was found the lacunarities at the fracturable area and breakable area both increased with the rise of pick-up pin diameter and decreased with the rise of initial pick-up angle. At the same pick-up conditions, lacunarities with the use of flat pins always surpassed that of circular pins. When circular pick-up pins with diameter of 2 mm and initial pick-up angle of 24 degrees were used, the destruction rate of root lumps (6.63%) was smaller than under other test conditions. The optimized pick-up parameters can be used to guide gripper design and to improve the working performance of automatic transplanters.