摘要
针对欠驱动双足机器人在已知变高度台阶上的稳定控制,提出了一种基于自适应前馈算法的稳定步行控制策略.首先,考虑地面变形,将地面等效为"弹簧—阻尼"系统,并建立"机器人—台阶"耦合动力学模型.其次,将"机器人—台阶"这一"多输入—多输出"模型简化为由质心位移和速度构成的"单输入—单输出"模型.然后,使用变坡度斜坡等效变高度台阶,根据台阶高度确定等效斜坡倾角和机器人理想步长;同时引入自适应控制系数,并根据等效斜坡倾角调整该控制系数,实现质心对参考速度的跟踪.最后,在台阶高度变化小于0.032m的环境中进行数值仿真试验,验证控制策略的有效性.仿真结果表明:本文提出的控制策略可以实现已知变高度台阶上的稳定步行.
In order to realize stable control of the underactuated biped robot on varying height steps with a known step height, a stable walking control strategy based on the adaptive feedforward control algorithm is proposed. Firstly, considering the ground deformation,pairs of spring-damper units are employed to model the ground,and a "robot-step" coupling dynamic model is established. Secondly, the "multiple-input-multiple-output" model of "robot-step" is simplified to the "single-inputsingle-output" model consisting of centroid displacement and velocity. Then varying height steps are equivalent to varying slopes, whose equivalent slope angle and the desired step length for each step can be calculated according to the each step height. An adaptive control coefficient is introduced into the control algorithm, and it is adjusted according to the equivalent slope angle to track the reference velocity of the CoM(center of mass). Finally, simulation experiments are conducted to validate the proposed controller in the environment where the varying height of the step is less than 0.032 m. The simulation results demonstrate that stable walking can be achieved on varying height steps with a known step height by implementing the proposed control strategy.
出处
《机器人》
EI
CSCD
北大核心
2018年第5期712-722,共11页
Robot
基金
国家自然科学基金(51675385)
中央高校基本科研业务费(2042016kf1166)
关键词
双足机器人
连续台阶
变高度
等效斜坡
欠驱动步行
前馈控制
biped robot
continuous steps
varying height
equivalent slope
underactuated walking
feedforward control
