伸缩腿双足机器人半被动行走控制研究

STUDY ON WALKING CONTROL OF A SEMI-PASSIVE BIPED ROBOT WITH TELESCOPIC LEGS

研究半被动伸缩腿双足机器人行走控制和周期解的全局稳定性问题.使用杆长可变的倒立摆机器人模型,以支撑腿的伸缩作为行走动力源,采用庞加莱映射方法分析了双足机器人行走的不动点及其稳定性.当脚与地面冲击时,假设两腿间的夹角保持为常数,设计了腿伸缩长度的支撑腿角度反馈控制率.证明了伸缩腿双足机器人行走过程不动点的全局稳定性.仿真结果表明,本文提出的腿伸缩长度反馈控制可以实现伸缩腿双足机器人在水平面上的稳定行走,并且周期步态对执行器干扰和支撑腿初始角速度干扰具有鲁棒性.

In this paper, the global stability of periodic solutions and walking control of a semi passive biped robot with telescopic legs are studied. An inverted pendulum with variable length is used as the robot model, and the biped robot is powered by elongating and shortening the stance leg. The fixed point and its stability of the biped robot walking are discussed based on Poincaré map. With the assumption that the angle between two legs keeps constant, when the swing leg impacts with ground at heel strike, the control law of telescopic length of the stance leg is designed by feedback of the angle between stance leg and vertical line. Then, the global stability of the fixed point is proved for the biped robot walking with telescopic legs. The simulation results show that the proposed feedback control law can make the biped robot with telescopic legs walk stably on the level ground, and the cycle gait is robust to the various disturbances of the actuator and the disturbances of the initial angular velocity of stance leg.