Abstract: A kind of electrically driven quadruped bionic robot is designed,which has the main and passive structure and the robot’s leg joint structure based on the electric cylinder.The purpose is to explain how the quadruped robot walks.D-H coordinates are given a kinematic calculation method.Kinematic modeling,the inverse kinematics calculation of robot with the aid of kinematic model,the corner function of the joints of the robot was solved.A method of gait planning for a four legged robot is proposed for the walking of a robot.Simulation experiments show that,the robot walks stably,the foot trajectories are smooth and the undulation of body has small amplitude.

Key words: quadruped bionics, D-H coordinates, foot trajectory, gait planning, motion simulation