基于质心调整的四足机器人转弯步态规划

Turning Gait Strategy for Quadruped Robot Based on Adjustment of Center of Mass

针对四足机器人转弯过程中容易失稳的问题,提出了一种基于零力矩点(ZMP)稳定性判据动态调整质心的改进型转弯步态规划方法,提高了四足机器人转弯时的动态稳定性。该步态规划方法根据ZMP稳定性判据规划ZMP参考轨迹始终处于对角支撑线上,确保机器人具有最大的稳定裕度。通过线性倒立摆和ZMP结合的模型得到连续平滑的质心调整参考轨迹,利用坐标系间的参数变换矩阵将足端轨迹转换到机身坐标系下求解期望的关节角。最后,利用MATLAB和ADAMS进行仿真分析,仿真结果验证了所提转弯步态规划方法的有效性。

In order to solve the stability problem of quadruped robot during turning, an improved turning gait planning method based on zero moment point(ZMP) stability criterion is proposed to dynamically adjust the center of mass(COM), which improves the dynamic stability of quadruped robot during turning. Based on ZMP stability criterion, the ZMP reference trajectory is planned to drive the ZMP on the supporting diagonal lines to ensure the maximum stability margin. A smooth COM reference trajectory is obtained by the model of linear inverted pendulum combined with ZMP. By using transformation matrix between coordinate systems, the foot trajectory is converted to the body coordinate system to obtain the desired joint angles. Finally, the simulation results obtained by MATLAB and ADAMS show the validity of the proposed turning gait strategy.