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为确定蒜薹的机械化采摘参数,以收获期蒜薹为对象,进行不同部位蒜薹的拉伸和压缩试验,以及整根蒜薹的拉伸试验。结果表明:拉伸初期,拉应力与应变近似线性增长,表现出弹性材料的特征;当应变增大到一定值时,拉应力随着应变缓慢增大,表现出弹塑性材料的特征。从顶部到根部,蒜薹的最大拉应力单调递减,最大压力总体呈现减小的趋势,蒜薹的弹性性能逐渐减弱,相同压力下的压缩变形量依次减小。当拉伸速度为20mm/min时,90%的蒜薹在根部断裂,此时最大拉应力为(1.2±0.1)MPa,最大应变为0.15±0.04。采摘机械手夹持蒜薹的最佳部位为蒜薹中部以上,夹持载荷应<4.1N/mm。可用对数函数和多项式函数分别表达蒜薹的拉应力与应变及压力与压缩变形量的关系。
In order to determine the mechanical picking parameters of garlic sprouts, the garlic sprouts at the harvesting stage were used for the tensile and compression tests of garlic sprouts in different parts and the tensile test of the whole garlic sprouts. The results show that tensile stress and strain increase linearly at the initial stage of tension, showing the characteristics of elastic material. When the strain increases to a certain value, the tensile stress increases slowly with the strain increasing, which shows the characteristics of the elastic-plastic material. From the top to the root, the maximum tensile stress of garlic sprouts decreased monotonically, the maximum pressure showed a decreasing tendency in general, and the elastic properties of garlic sprouts decreased gradually. The compressive deformation under the same pressure decreased in turn. When the tensile speed was 20mm / min, 90% of garlic sprouts broke at the root, the maximum tensile stress was (1.2 ± 0.1) MPa and the maximum strain was 0.15 ± 0.04. The best place for the picking robot to hold the garlic sprouts is above the middle of the garlic sprouts. The holding load should be <4.1N / mm. The relationship between tensile stress, strain and pressure and compressive deformation of garlic sprouts can be expressed by logarithmic function and polynomial function respectively.