为缓解液压驱动足式机器人动态步态行走时着地瞬间足端冲击对机器人系统及其运动控制的影响,提出了一种基于关节运动规划的机器人柔顺着地控制方法。以液压驱动单腿跳跃机器人为研究对象,分析机器人足端着地冲量,通过选择合适的机器人着地姿态和减小机器人着地前足端速度实现机器人柔顺着地,为此在空中相进行余弦速度曲线关节运动轨迹规划,以及着地相进行余弦函数关节运动轨迹规划。将该方法分别应用于基于MATLAB/Simulink软件建立的仿真模型和试验样机进行单腿竖直跳跃控制实验,仿真和试验结果显示采用该方法的机器人跳跃控制消除了足端着地瞬间地面作用力在膝关节液压缸无杆腔形成的液压冲击,实验结果表明提出的基于关节运动规划的机器人柔顺着地控制方法合理可行。
With the purpose of releasing the effect of the impulse to the robot system and its motion control for the instant the hydraulically actuated legged-robot touching down with the dynamic gait,a robot' s compliant touch-down control method based on the joint motion planning is presented. Focusing on the hydraulically actuated single-legged robot as the research object,two ways of robot compliant touch-down is obtained by analyzing the end-effector's impulse,which selects the proper touch-down posture of the robot and reduces the end-effector's velocity before touching down the ground. Furthermore,the joint motion trajectory on both of the flight phase and stance phase are planned. The former is based on the cosine velocity curve and the latter is based on the cosine function curve.Afterwards,the method is applied to the hopping control of the hydraulically actuated single-legged robot emulated on MATLAB/Simulink and then to the robot prototype. Both of the emulated and experimental results indicate that the pressure impulse in the hip cylinder's rodless chamber after the robot' s end-effector touching down the ground is eliminated. Experimental results verify that the robot's compliant touch-down control method based on the joint motion planning is reasonable.