Modeling And Kinematics Analysis Of Multi-legged Robot Based On Screw Theory

In recent decades,China has made remarkable achievements in infrastructure construction,and due to frequent security problems,a new targeted detection scheme is urgently needed.This paper designs a multi-legged robot detection platform for high-rise building walls and large bridges.The robot has six legs and belongs to a kind of parallel robot.It has good environmental adaptability and motion flexibility.It can not only complete various movements on the flat ground,but also climb to the side of wall for inspection.This paper mainly carries out research work from the aspects of mechanical structure design,forward and inverse kinematics analysis,kinematic performance analysis,gait planning and simulation analysis.Firstly,this paper introduces the research significance and sources of this topic,and summarizes the research status of related fields at home and abroad,and analyses the key issues in the research of multi-legged robots,laying the research significance and design ideas of this paper.At the same time,the overall design of the multi-legged robot prototype is introduced from the aspects of the overall structure and control system.Then,based on D-H parameter method and screw theory,the forward kinematics model of multi-legged robot is established,and the model is consistent.At the same time,the relationship between the two methods is analyzed.It is concluded that both modeling methods can be used to analyze the same problem,but the descriptive methods are different,and there is a transformation relationship between the two methods.On the basis of establishing the forward kinematics model,the inverse kinematics solution of the robot is obtained by solving the equations,which is verified by the Gazebo simulation software under ROS(Robot Operating System).Then,in order to make the motion of the robot more stable,compliance and flexible,the speed and acceleration model of the multi-legged robot is established based on the screw theory,and the relationship between the speed and acceleration of the end of the robot and each joint is obtained.On the basis of the Jacobian matrix of the robot speed,the singularity problem of the robot is analyzed,and the conditions for the singularity of the robot are obtained.The dexterity performance of the robot is quantitatively analyzed by using Jacobian-based condition number and manipulability.The influence curve of each joint on dexterity of the robot is obtained by using MATLAB software.Finally,the gait planning of the multi-legged robot is studied,and the gait is designed according to the movement requirements of straight line walking,steering and climbing wall.In the Gazebo simulation environment of ROS,the gait is simulated and analyzed.Finally,the gait experiment of the multi-legged robot is carried out on the real prototype.