基于螺旋理论的冗余液压驱动四足机器人运动学分析

Kinematic analysis of redundant hydraulic actuated quadruped robot based on screw theory

四足机器人的各种研究大多基于四条腿弯曲方向一致展开的。对于液压驱动且具有冗余度的四足机器人,静止姿态下,其前面两条腿与后面两条腿成对称弯曲状。为了研究这种机器人单腿运动和躯体运动状态,文中建立了基于螺旋理论的液压驱动四足机器人运动学模型,包括给出了单腿串联运动学逆解和躯体并联运动学正解。然后根据机器人行走过程设计出后面两条腿的髋关节与膝关节摆幅角度,通过建立的运动学模型,得到前面两条腿的关节变量及躯体姿态。最后通过MATLAB数值仿真和ADAMS虚拟样机实验,对机器人在一种行走方案下的躯体运动姿态进行仿真对比,验证了所建运动学模型的可靠性。

Research on quadruped robot is mostly made based on the same bend directions of four legs. For redundant quadruped robot, its two forelegs and rear legs become symmetry flections in steady poses. For studying a leg motion and the body motion of hydraulic actuated redundant quadruped robot, kinematic model of quadruped robot was established based on screw theory in this paper, which includes inverse kinematics solution of a single leg and forward solution of the parallel body. Then, the angle ranges of coax joints and knee joints of two rear legs were designed according to the walking plan of robot. Furthermore, the joint variables of two forelegs and the poses of the body were obtained by the mathematical model. Finally, the body posture in a walking plan was compared by MATLAB calculation and ADAMS simulation, and the kinematics model was validated.