基于贝塞尔曲线的四足机器人足端轨迹规划研究

RESEARCH ON TRAJECTORY PLANNING OF QUADRUPED ROBOT BASED ON BEZIER CURVE

为了提高四足机器人对角小跑步态的平稳性,提出一种基于贝塞尔曲线的足端轨迹规划方法。针对四足机器人的对角小跑步态,建立了四足机器人并联腿运动学模型,运用几何法求解了正逆运动学,并基于零冲击原则和比例微分(Proportion and Differentiation,PD)控制器对摆动相和支撑相的足端轨迹进行优化;利用Webots仿真平台和实验样机进行对比试验。结果表明:当X方向上比例系数取20,微分系数取0.75 s,Y方向上比例系数取20,微分系数取0.5 s时,四足机器人的足端轨迹平滑且无速度、加速度突变,对角小跑步态更为稳定。

In order to improve the stability of diagonal trot gait for quadruped robot,a foot end trajectory planning method based on Bezier curve is proposed.Aiming at the diagonal trot gait of quadruped robot,the kinematics model of parallel legs of quadruped robot is established,the forward and inverse kinematics are solved by geometric method,and the foot end trajectories of swing phase and support phase are optimized based on zero impact principle and PD controller.The comparative test is carried out by using Webots simulation platform and experimental prototype.The results show that when the proportional coefficient in X direction is 20,the differential coefficient is 0.75 s,the proportional coefficient in Y direction is 20 and the differential coefficient is 0.5 s,the foot end trajectory of quadruped robot is smooth without sudden change of speed and acceleration,and the gait of diagonal trot is more stable.