Design and Testing of Discrete Element-Based Counter-Rotating Excavation Device for Cyperus esculentus

Currently, the mechanized harvesting method of Cyperus esculentus is mainly based on rotary excavation, but there are problems such as high working resistance, high damage rate, and high buried fruit rate in the working process. This paper focuses on the analysis of the movement trajectory of the positive-rotating and counter-rotating Cyperus esculentus excavation device, establishes a agglomerate model of soil-Cyperus esculentus tuber-Cyperus esculentus root system-mechanism, and conducts discrete element simulation tests on Cyperus esculentus agglomerates under different soil layers. According to Expert test optimization, the optimal structural parameters of the counter-rotating blade are determined: the radius of gyration is 151 mm, the inclination angle of the cutting edge is 42.5°, and the working width is 318 mm. The comparative test of the positive-rotating rotary tillage method under the optimal structural parameters shows that the working resistance is reduced by 11.25%, and the torque of the tool shaft is reduced by 16.11%, which proves that the designed anti-rotation excavation structure has the effect of reducing resistance. To further test the harvesting performance of the Cyperus esculentus excavation device, field harvesting tests were conducted, and the results showed that the buried fruit rate of the counter-rotating excavation device was reduced by 11.6%, and the damage rate was reduced by 6.1% year-on-year. This study shows that the design of the counter-rotating excavation device can further improve the harvesting performance of Cyperus esculentus based on reduced resistance harvesting and meet the requirements of Cyperus esculentus harvesting.