Research On Structural Design And Motion Planning Of Quadruped Robot In Complex Ground Environment

On land,nearly half of the area is an unstructured complex ground environment.For tracked or wheeled machinery,it cannot fully adapt to this type of environment,so foot-type robots have emerged.The research of quadruped robots has always been the focus of people’s attention,because it has more advantages than other types of robots in terms of environmental adaptability.In order to improve the adaptability of the quadruped robot in the complex ground environment,this article has carried out research on the four-legged robot with foot-wheel conversion.This type of robot can change two motion modes(wheeled motion and footed motion)according to different environments.Increase the flexibility of movement and the ability to adapt to the complex ground environment.Whether the robot can be used in practice,the foot movement of the robot is the key factor that affects the problem.Therefore,this article mainly focuses on the following research on the foot movement of the robot:(1)Structural design and kinematics analysis of quadruped robot based on G_FsetIn order to design a reasonable leg structure and improve the stability of the quadruped robot at the structural level,the G_Fset theory with rich configuration is introduced,and the leg structure of the robot in the crawling gait is carried out based on this theory.Design,and then establish the three-dimensional model of the quadruped robot and build the experimental prototype;on this basis,perform single-leg series kinematics analysis and body parallel kinematics analysis to obtain the expression of the joint angle of each driving joint of the robot.(2)Gait Planning and Stability Analysis of Quadruped RobotIn the stability analysis,in order to be able to accurately judge the static stability of the quadruped robot,a judgment criterion(SA criterion)based on the deflection angle and the stability margin is proposed,which is used in the gait planning of the quadruped robot,Verified the feasibility of the method.In the gait planning,based on the crawling gait,the six basic leg steps of the quadruped robot are analyzed,and the optimal leg step sequence is obtained.On this basis,the quadruped robot walks in a straight line and the original Research on gait planning for ground turning and turning movement.An experimental prototype was built,and the robot was subjected to straight and turning gait experiments to verify the rationality of the gait planning.(3)Quadruped robot path planningIn the robot path planning,the RRT algorithm is introduced.Aiming at the problem of slow convergence of the RRT algorithm,improvements are made on the basis of the algorithm.Through simulation experiments,the feasibility of the improved RRT algorithm in improving the convergence speed is verified.