Design And Gait Planning Of Link Driven Bionic Quadruped Robot

In recent years,quadruped robot has become a hot research subject in the fields of bionic foot robots.The research results of many universities and companies have emerged in large numbers,and more and more quadruped robots with different shapes appear in front of people.However,the adaptability of the quadruped robot in the field is far from enough.Whether a quadruped robot can move stably is closely related to the design of foot trajectory.It is a key issue in the gait planning and stability control of the quadruped robot.This paper mainly studies the quadruped robot with link leg structure,analyzes the main factors of sliding friction between the foot and the ground.Based on the cycloid trajectory,two kinds of foot trajectories are designed to effectively improve the friction and reduce the degree of foot sliding,so as to improve the running speed of the robot.Firstly,according to the analysis of the motion function of quadruped muscle and skeleton structure in bionics,a connecting link-driven quadruped robot is designed.Using DH method,the kinematics analysis coordinate system is established,and the forward and inverse kinematics equations of the link-driven leg are deduced.At the same time,the inverse kinematics control block diagram is built by using the relationship between joint variables and terminal velocity in inverse kinematics.Secondly,the dynamics of the supporting phase and the swing phase of the link-driving leg are analyzed in detail,and the relationship equation between the foot speed,joint rotation angle and joint moment is deduced.Combined with the inverse kinematics control method,a control block diagram based on the inverse kinematics of the operating space is built.By comparing the errors in the simulation software,it is found that the control effect based on the inverse kinematics of the operating space is closer to the preset trajectory.Next,the gait planning method of the quadruped robot is studied,and the suitable gait and related parameters are selected.The main factors of the slippage of the foot during the movement of the quadruped robot are analyzed.From the bionic point of view,the vertical motion of the body is introduced into the supporting phase,and the foot trajectory is designed to effectively increase friction and reduce slippage.Finally,in order to prove the application effect of the two kind of foot trajectories in the gait planning of the quadruped robot,a virtual prototype and control platform are built in the software.Joint simulation of the link-driven quadruped robot is carried out to analyze the effects of the two foot trajectories on the speed of the quadruped robot,the force of the foot and the stability of the motion.