Locomotion control for the planar articulated leg robot based on the positon decoupling algorithm

Abstract

This paper presents a position control algorithm based on the kinematics model to perform motion control in the planar articulated leg robot. The simplified planar robot has two articulated legs, each of which has two degrees of freedom (DoF), the knee and the hip joints, and a rotating joint without actuation, the foot. After a brief description of the planar model, the kinematics analysis is performed and developed. And then, in order to achieve the stable motion, controllers in the stance and swing phase are designed. Meanwhile, some strategies are described to contribute to the locomotion, which consists of the forward velocity estimation, placing the feet in key locations on each step, motion planning and the friction cone constraints. Last but not least, the simulations of the stable motion and the maximum velocity are carried to verify the feasibility of the planar model and the designed controllers. The results indicate that the proposed position control is effective to the motion of the planar articulated leg robot and the maximum forward velocity can reach 0.5m/s under the existing conditions.