一款仿蚯蚓机器人的纤维驱动特性建模与辨识

Actuation Feature Modeling and Identification of a Fiber-Driven Earthworm-I ike Robot

针对一款Yoshimura折纸结构仿蚯蚓移动机器人,本文提出了基于人工肌肉纤维驱动的折展-纤维机器人新构型.该人工肌肉纤维为镀银尼龙线材质,以电热方式实现纤维收缩驱动,是一种典型的力电热耦合材料.考虑到其力电热耦合特性尚未明确,本文首先基于第一性原理提出了等长收缩状态下驱动电流-纤维温度微分模型,并通过NSGA-Ⅱ算法精确辨识了模型各参数.进一步,基于数据驱动建模方式明确了等长收缩状态下纤维温度-收缩力关系以及等温收缩状态下纤维变形-收缩力关系,最终实现了人工肌肉纤维力电热耦合特性的精确刻画,为新型仿蚯蚓移动机器人的运动性能分析和优化提供了理论基础.

In this paper,a new configuration of an earthworm-like robot with Yoshimura-origami structure and artificial muscle fiber actuation is proposed.The artificial muscle fiber is made of silver-plated nylon wire,which realizes its contraction by electric heating.It is a typical electro-thermo-mechanical coupling material.However,the electro-thermo-mechanical coupling characteristics of the fiber are not clear.To this end,based on the first principle,the differential model between the driving current and the fiber temperature under isometric contraction is proposed first.Then,the parameters of the model are identified using the NSGA-Ⅱalgorithm.Further,based on the data-driven modeling method,the relationship between the fiber temperature and contraction force under isometric contraction and the relationship between the fiber deformation and contraction force under isothermal contraction are clarified.Finally,the accurate description of the electro-thermo-mechanical coupling characteristics of the artificial muscle fiber is realized,which lay the foundation for the analysis and optimization of the motion performance of the new earthworm-like robot.