蚯蚓直线运动的三轴地面反作用力:测量、分析和对机器人建模的影响

Triaxial ground reaction forces of earthworm rectilinear locomotion:measurement,analysis,and implications for robot modeling

蚯蚓在狭窄受限环境中具有良好的移动性,但其在运动过程中与地面的三轴反作用力还未被深入研究.本文探讨了蚯蚓在直线运动过程中的三轴地反力特征及其对机器人建模的影响.具体地,本研究设计了一个基于应变片的三轴微型测力板来测量蚯蚓(P.guillelmi)在直线运动时的三轴地反力.通过建立地反力的时间历程与运动视频的对应关系,将蚯蚓的周期性运动划分为三个阶段,并从蚯蚓身体变形的角度解析了地反力在三个阶段的力学特征.本研究还对蚯蚓的地反力特征进行了统计分析,并建立了蚯蚓直线运动过程的阻力系数模型.以此为基础,本文还提出了与机器人节段/单元变形相关的阻力系数模型,为离散型和连续型仿蚯蚓机器人的动力学建模提供基础.本研究首次对蚯蚓运动过程中的mN级三轴地反力进行了测量、分析和建模,研究结果对蚯蚓运动生物力学、仿蚯蚓移动机器人设计和机器人-环境接触界面调控等具有重要的指导意义.

Although earthworms are recognized for their excellent mobility in confined environments,little is known about the triaxial ground reaction forces(GRFs)they produce during locomotion.This study explores the triaxial GRF characteristics of the earthworm during rectilinear locomotion and their implications for robot development.A strain gauge-based triaxial miniature force plate is designed to measure the triaxial GRFs of Pheretima guillelmi during rectilinear locomotion.By correlating the time histories of the measured GRFs with recorded videos,the motion of one cycle of the earthworm is divided into three phases,and the relationship between the deformation of the earthworm’s body and the characteristics of the GRFs is established.Based on the experimental data of nine subjects,this study also statistically analyzes the characteristics of the GRFs and derives a model of the earthworm’s resistance coefficient during its rectilinear motion.Furthermore,this study presents models of resistance coefficients closely related to robot segment/section deformations for both discrete and continuous configurations of earthworm-like robots.The results of this study are instructive for understanding earthworm locomotion biomechanics and designing and regulating the interface between the earthworm-like robot and the ground.