基于狗獾前足趾结构特征的捡石机仿生减阻挖掘铲设计与试验

Design and Experiment of Biomimetic Drag-reducing Excavating Shovel for Stone-picking Machine Based on Foretoe Structure of Badger

摘要:

针对传统捡石机挖掘铲在海南红壤田间作业中存在挖掘阻力大、能耗高的问题,基于狗獾前爪趾结构,设计了两种高效减阻的仿生挖掘铲,并采用离散元仿真方法分析其减阻性能。以海南地区典型红壤及石块作为研究对象,石块设为刚性体,土壤颗粒之间采用Hertz–Mindlin with JKR接触模型,建立了石块土壤离散元的复合体模型;通过三维扫描技术获取狗獾前爪第3趾和石块的外部形态尺寸数据,提取关键几何特征参数并运用Solidworks软件建立仿生挖掘铲和石块三维模型,根据爪趾数字化模型设计了仿生挖掘铲1型和仿生挖掘铲2型两种挖掘铲;以挖掘阻力为主要评价指标,采用EDEM离散元法建立土壤石块挖掘铲相互作用模型,分析仿生挖掘铲的减阻机理,通过仿真结果计算得出仿生挖掘铲1型、仿生挖掘铲2型减阻率分别为8.37%和15.43%。通过开展田间试验,对比挖掘阻力和碎土效果,仿生挖掘铲1型、仿生挖掘铲2型和平面挖掘铲平均挖掘阻力分别为1 384.9、1 296.4、1 497.7 N,仿生铲减阻率分别为7.52%和13.42%,与仿真结果接近,其中仿生挖掘铲2型作业后土壤颗粒粒径更小,说明仿狗獾挖掘铲2型铲具有良好的减阻特性和破土性能,能满足红壤条件下石块挖掘作业。

Abstract:

Aiming to address the issues of high excavation resistance and excessive energy consumption encountered by traditional stone-picking excavator shovels during field operations in Hainan red soil, two biomimetic excavation shovels with enhanced resistance-reduction efficiency were designed based on the forepaw toe structure of the hog badger (Arctonyx collaris). The resistance-reduction performance of these shovels was analyzed by using the discrete element method ( DEM). Typical red soil and stones from Hainan were selected as research materials, with the stones modeled as rigid bodies, and soil-particle interactions described by using the Hertz – Mindlin with JKR contact model to establish a composite stone – soil discrete element model. The external morphological and dimensional data of the third forepaw toe of the hog badger and the representative stones were obtained via three-dimensional scanning technology. Key geometric features were extracted, and three-dimensional models of the biomimetic excavation shovels and stones were constructed by using Solidworks software. Based on the digital model of the paw, two biomimetic excavation shovels, designated Type 1 and Type 2, were designed. Excavation resistance was chosen as the primary evaluation index, and a soil – stone – shovel interaction model was established by using EDEM software to analyze the resistance-reduction mechanism of the biomimetic shovels. The simulation results revealed that the resistance-reduction rates for Type 1 and Type 2 biomimetic excavation shovels were 8.37% and 15.43%, respectively. Field experiments were conducted to compare excavation resistance and soil-breaking performance. The average excavation resistances of Type 1 and Type 2 biomimetic excavation shovels and the conventional flat shovel were 1 384.9 N, 1 296.4 N and 1 497.7 N, respectively, corresponding to resistance-reduction rates of 7.52% and 13.42%, which closely aligned with the simulation results. Moreover, soil particles produced after operation with Type 2 biomimetic excavation shovels exhibited a smaller particle size distribution, indicating that the hog badger-inspired Type 2 shovel demonstrated superior resistance-reduction and soil-breaking performance, making it well-suited for stone excavation operations in red soil conditions.