Study on Plant Crushing and Soil Throwing Performance of Bionic Rotary Blades in Cyperus esculentus Harvesting

Abstract

Soil blocking and plant entanglement are the main challenges in Cyperus esculentus harvesting and excavating. The structure of the rotary blade is one of the critical factors affecting plant crushing and soil throwing performance. Inspired by the composite motion of longitudinal soil cutting and lateral soil throwing of the oriental mole cricket, a bionic rotary blade was designed with the contour curve of the excavation edge and excavation surface of its forefoot claw toe. The bionic rotary blade’s mechanical and kinematic analysis revealed its cutting mechanism. A flexible plant soil, bionic, rotary blade discrete element model was developed to simulate the Cyperus esculentus digging process. The optimal excavation edge and excavation surface were selected by a single factor experiment, and the optimal operating parameters of the bionic rotary blade were obtained by quadratic regression orthogonal rotational combination design. The results showed that the bionic rotary blade, based on the excavation edge and excavation surface of mole cricket first claw toe, had the longest throwing distance and the largest number of broken bonds. The best combination of operating parameters of the bionic rotary blade was 11.16 mm for blade spacing, 0.66 m/s for forward speed, and 300 rpm for shaft speed. The field experiment was carried out according to the best parameters. The results showed that the bionic rotary blade’s average soil throwing distance and plant crushing rate were 632.30 mm and 81.55%, respectively; thereby, not only meeting the requirements of Cyperus esculentus harvesting, but proving superior to the operation performance of the Chinese standard rotary blade IT245 and rotary blade with optimized cutting edge (IT245P). The results of this study can provide bionic design ideas and methods for the design of soil-cutting-based tillage machinery’s soil-engaging components, such as the rotary blade and returning blade.

Biomimetic Design of Soil-Engaging Components: A Review

“…The curved-toothed disc not only met the drag reduction performance but also further improved the straw-cutting efficacy by 26.31% [31]. [24], (b) tea garden bionic subsoiler [8], (c) bionic rotary blade [24], (d) bionic fixed hole-forming device [20].…”

“…Three-dimensional reconstruction can often extract contour curves more accurately. Zhu et al [ 24 ] reconstructed the three-dimensional model of the claws of the mole cricket’s front feet. Based on this, they extracted the contour curves of the edge and the excavation surface.…”

“… Low-resistance soil-engaging components inspired by mole crickets. ( a ) Structure of the claw toes on the forefoot of the mole cricket [ 24 ], ( b ) tea garden bionic subsoiler [ 8 ], ( c ) bionic rotary blade [ 24 ], ( d ) bionic fixed hole-forming device [ 20 ]. …”

Simulation Analysis and Optimization Design of Paddy Field Mud Spreader Blades for Uniform Dispersion

“…Scholars have extensively researched the operational performance of blades used in agricultural machinery in soil environments. Some researchers have explored altering particle trajectories by designing blades of different shapes to influence the movement of soil particles along predetermined paths [12][13][14][15]. Others have investigated the cutting and scattering processes of blades to uncover underlying patterns of particle motion [16][17][18][19][20].…”

Design and Test of a Crawler-Type Tiger-Nut Combine Harvester

“…The optimal combination of working parameters of the threshing and separating device was obtained. Zhu et al [18] developed a discrete element model of flexible plant soil and bionic rotating blades to simulate the process of sedge excavation. Zhao et al [19] combined the characteristics of the agglomerates of the tiger-net, and a multi-channel transportation device for the tiger-net was designed, to realize the transitional conveyance of the agglomerates of the tiger-net.…”