髋关节含库伦摩擦被动行走器动力学建模与仿真研究

被动动力行走是当今双足步行机器人研究的重点之一,学者对被动行走器髋关节的摩擦对其步态影响还存在分歧。该文对髋关节含库伦摩擦的直腿被动动力行走器的建模和仿真,以及摩擦对行走器步态的影响进行了研究。首先推导了髋关节含库伦摩擦的被动行走器的动力学方程,该动力学方程为非线性非光滑的隐式常微分方程组；然后给出了一种基于试算法求解该动力学方程的数值计算方法；最后通过数值仿真分析了髋关节的摩擦对被动行走器步态的影响。研究成果为以后被动动力行走研究提供了一个更接近实际的模型,为数值仿真分析其动力学特性提供了一种工具。

A STUDY OF THE MODELING AND SIMULIATION OF A PASSIVE DYNAMIC WALKER WITH COULOMB FRICTION AT THE HIP JIONT

Passive dynamic walking is one of the important topics in the field of biped robots,but the effect of friction at the hip joint upon the gait of a passive dynamic walker is still a controversial problem.Thusly the study of the modeling,simulation and gait of a straight leg biped passive dynamic walker with Coulomb friction at the hip joint is presented.The dynamic equations of a passive dynamic walker with Coulomb friction at the hip joint are first derived,and these equations are non-linear and non-smooth implicit differential equations.Then,a new numerical scheme for the dynamic equations is proposed by using a trial-and-error method.Finally,the effect of Coulomb friction on the walker’s gait is investigated by numerical simulation.The results of the present study are expected to be useful for the modeling and simulation of passive dynamic walking.