双足被动行走模型局部稳定性分析

Analysis of local stability of biped passive dynamic walking model

为了实现双足被动机器人进行稳定周期行走,给出了求解双足被动模型不动点的方法,并详细分析了被动行走模型各机械参数和斜面坡度对稳定不动点存在的影响,并分析各参数在给定初始条件下,对模型收敛到稳定周期运动状态速度的影响以及各参数对模型稳定不动点状态变化的影响.结果表明:较小的腿质量(m∈[0.3kg,30kg]),较高的质心位置(Kc∈[0.0304,0.6240]),合适的足半径(Kr=0.16),较大的转动惯量(KJ=0.128)以及合适的斜面坡度(β∈[0.02rad,0.1rad]有利于提高被动机器人的局部稳定性.

To realize the stable walking cycle of passive biped robot, this paper presents a method to find the fixed point and a detailed analysis on the effect of the change of mechanical parameters of the passive walking model and slope gradient on the existence of stable fixed point is carried out. The effect for each parameter at the given initial conditions on the speed of converging to the stable cycle walking and the effect of changing status of stable fixed point from the change of the parameters are investigated. It is concluded that the smaller mass for legs, a higher location for the center of mass, the fight radius of foot, the larger moment of inertia as well as the fight slope gradient are beneficial for improving the local stability of the passive robot.