变刚度半被动双足机器人行走的仿人控制

HUMAN-LIKE CONTROL FOR SEMI-PASSIVE BIPEDAL ROBOT WALKING WITH VARIABLE LEG STIFFNESS

研究了变刚度半被动双足机器人行走控制问题。采用仿人的行走控制策略,使用变刚度双足弹簧负载倒立摆模型,利用模型自稳定性,在双支撑阶段调整后腿刚度使机器人的能量保持在期望能量附近,在单支撑阶段调整摆动腿落地位置控制质点的高度和前向速度。仿真结果表明:本文采用的控制策略可以实现双足机器人在水平面上的稳定行走,无扰动时可以使机器人实现零输入的被动周期行走,有外部扰动时腿部变刚度控制可使机器人总能量恢复平衡并重新进入稳态行走,控制系统具有鲁棒性。

For the walking control of the semi-passive bipedal robot with variable stiffness, the human-like walking control strategy is adopted. By using the self-stabilizing characteristics of the bipedal spring loaded inverted pendulum model with variable stiffness, the rear leg stiffness is adjusted in the double support phase to keep the robot energy near the desired energy, and the position of the swinging leg touching down on the ground is adjusted in the single support phase to control the altitude and the forward velocity of the desired point. The simulation results show that the human-like control strategy can ensure a stable walking of the bipedal robot in the horizontal plane. The robot can achieve the passive periodic walking with zero-input when there is no disturbance. With the variable stiffness control of the leg, the total energy of the robot can be restored to a balance state, the robot can re-enter the steady-state walking, and the control system is robust to the external disturbance.