带躯干变刚度双足机器人的周期行走控制

研究了带躯干双足机器人平面稳定行走控制问题。改进传统的弹簧-质点模型，得到带躯干的双足机器人模型，通过控制髋关节施加力矩和改变弹簧腿的刚度，使得系统收敛到期望步态。针对系统模型的非线性和强耦合特征，采用反馈线性化方法将系统的动力学模型转化成线性系统，采用PD控制和P控制对机器人的躯干倾角和髋关节轨迹进行整体控制。在理论分析的基础上，对控制方法进行了数值仿真研究。仿真结果表明:该文采用的反馈线性化和变刚度控制方法可以实现带躯干双足机器人的稳定行走；与基于时间轨迹的控制方法相比，该文基于空间轨迹的控制器对各种外力干扰具有良好的抵抗能力；控制器对躯干的倾角变化具有适应性；当模型不确定时控制器表现出优异的鲁棒性。

PERIODIC WALKING CONTROL OF BIPED ROBOTS WITH TORSO USING VARIABLE STIFFNESS ACTUATION

A spring-mass model with a torso represented by a rigid rod was proposed, whose stable walking control on level ground was analyzed. By controlling the torque of the hip joint and changing the stiffness of the spring legs, the system converged to the desired gait. According to the nonlinear and strong coupling characteristics of the system, the dynamic model was transformed into a linear system by the feedback linearization method. The PD control and P control were used to control the torso inclination and the hip joint trajectory of the robot. The numeric simulation results showed that the feedback linearization and variable stiffness control methods used in this study can realize the stable walking of the biped robot. It presented satisfactory anti-disturbance performance to external forces and the variation of inclination angle of torso with robustness.