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.
