低阻力三七挖掘复合仿生铲设计与试验

Design and Experiment of a Low-resistance Composite Bionic Digging Shovel for Panax notoginseng

摘要:

三七作为云南地区名贵中药材，其机械化收获存在挖掘阻力大的问题，减小挖掘阻力对提高三七机械化收获效率具有重要意义。针对这一问题，本文设计了一种新型复合仿生铲。通过理论分析确定了影响复合仿生铲挖掘阻力的因素：仿生刀长度、宽度和高度，铲体宽度、长度和铲刃斜角，结合上述因素和标定试验获得的物理参数，使用Hertz-Mindlin (no-slip)模型设计正交试验，得出挖掘阻力最小的复合仿生铲结构参数组合。设计跟踪颗粒位移流向的仿真试验，评估所提出的复合仿生铲减阻能力和挖掘效果。采用正交试验方法进行现场试验，确定了复合仿生铲最佳工作参数组合：入土角为15°，前进速度为0.3m/s，铲片中心间距为80mm；得到复合仿生铲的平均挖掘阻力为1094.51N，与平面铲、二阶铲和组合铲相比分别降低了25.30%、19.55%和10.76%。以上结果表明，所提出的复合仿生铲能够满足降低挖掘阻力、提高三七中药材机械化收获效率的需求。

Abstract:

Panax notoginseng is a valuable traditional Chinese medicine in Yunnan. The mechanized harvesting of Panax notoginseng has severe digging resistance. Reducing digging resistance has a significant impact on improving the efficiency of mechanized harvesting of Panax notoginseng. To address this issue, a composite bionic shovel was proposed. The factors affecting the digging resistance of composite bionic shovel were determined through theoretical analysis as follows: the length, width and height of the bionic knife, the width, length and bevel angle of the shovel blade. By combining the above factors and the physical parameters obtained from the calibration test, an orthogonal test was designed by using the Hertz-Mindlin (no-slip) model. The combination of composite bionic shovel structural parameters with the smallest digging resistance was obtained. Simulation tests of tracking the particle displacement flow direction were designed to evaluate the resistance reduction capability and excavation effect of the proposed composite bionic shovel. Based on verifying the simulation test through field tests, the best combination of working parameters of the composite bionic shovel was determined by using orthogonal test methods in the field test under the shed environment of the team as follows: the entry angle was 15°, the forward speed was 0.3m/s, and the center distance of the shovel blade was 80mm. The composite bionic shovel exhibited an average digging resistance of 1094.51N. This value was reduced by 25.30%, 19.55%, and 10.76% compared with the following shovels that were effective in Panax notoginseng excavation: the flat shovel, second-order shovel, and combination shovel, respectively. The above results showed that the proposed composite bionic shovel can meet the requirements of reducing the digging resistance and improving the mechanized harvesting efficiency of Panax notoginseng.