带仿生躯干的被动行走机器人步态特性

Gait Properties of Passive Walking Robots with Bionic Torso

为改善被动行走机器人的步态特性,受人体躯干同时具有刚性骨骼和柔性软组织启发,提出一种带刚柔仿生躯干的被动行走机器人模型,并研究其非线性动力学特性.将仿生躯干柔性部分等效为带质量的弹簧阻尼器,建立仿生躯干被动行走机器人的动力学模型.分别分析仿生躯干的等效弹性系数、等效阻尼系数、等效质量对被动行走机器人的行走步长和步行速度的影响规律,并与刚性躯干模型的结果进行对比.研究结果表明:相比于刚体躯干,仿生躯干使得被动行走具有更加丰富的步态行为;仿生躯干柔性不仅影响被动行走的行走步长及行走速度,还影响被动行走的稳定性;适当的躯干柔性可以在维持稳定周期步态的同时,提高被动行走机器人的行走步长及步行速度;与刚性躯干相比,带仿生躯干的被动行走步长能提高12%,行走速度能提高2%.

Inspired by the fact that a human torso has both rigid skeletons and flexible internal organs,a passive walking robot model with a rigid and flexible bionic torso was proposed to improve the gait property of the robot,and the nonlinear dynamic properties of the robot were studied.First,the dynamic equations of the passive walking robot with a bionic torso were established by considering the flexible part of the torso as a mass-spring-dashpot system.Then,the effects of the equivalent elasticity coefficient,damping coefficient,and mass of the bionic torso on walking step length and walking speed of the robot were investigated respectively.The results show that compared with the rigid torso,the bionic torso enables a more abundant gait behavior for a passive walking robot.The flexibility of the bionic torso affects the walking step length,walking speed,and walking stability of a passive walking robot.With appropriate torso flexibility,the walking step length and walking speed of the robot can be improved while the stable periodic gait remains.Compared with the rigid torso,the walking step length and walking speed of the robot with a bionic torso can be increased by 12%and 2%,respectively.