Research On Digital Twinning System For Quadruped Robot

The legged legged structure of the animal movement is flexible,environmental terrain adaptation ability,almost spread across most of the Earth’s land.Due to the rapid development of economy and society,scientists have developed new mobile robots,such as biped robot,quadruped robot,hexapod robot and so on.As the current research and development technology of quadruped robot is not mature,some parts of the robot are easy to be damaged during the experiment,leading to the experiment delay or failure.Therefore,this paper studies the digital twin system of quadruped robot.The work content is divided into four aspects: quadruped robot design and manufacture,leg model establishment and synchronization control strategy research,digital twin system construction and simulation,physical and RViz visualization platform and Gazebo dynamics platform joint experiment.Firstly,this paper takes quadruped robot as the research object,analyzes and designs quadruped robot according to the movement characteristics of dog quadruped animal,and studies its structure and movement form.Design and optimize the parts of the quadruped robot,draw two-dimensional drawings and processing,build the quadruped robot physical experiment platform.Secondly,the leg model of the quadruped robot is built and the synchronization control strategy is proposed.The four-legged robot has complex motion process and obvious motion constraints at different stages when walking,so it is necessary to study and analyze the motion equation of one-legged dynamics.Therefore,the leg model of the four-legged robot is established,and the Lagrange dynamics equation is used to derive and calculate the dynamics of the one-legged system.The deviation coupling synchronization control strategy is designed to reduce the synchronization control errors of physical and simulation robots.Then,the digital twin system of the quadruped robot was constructed,and the simulation experiment was carried out on the Gazebo platform of ROS.The URDF model of the quadruped robot was built through the three-dimensional model,and the virtual simulation environment was built by Gazebo and RViz platforms in ROS.Then the communication mechanism between the physical entity and the digital twin is written,and the data is transferred to the digital twin to realize the follow-up control.The simulation results show that the walking state of the robot is stable.Finally,the physical platform,RViz visualization platform and Gazebo dynamic platform were tested.Write RViz visual display platform plug-in to realize the visualization of robot data.Since the performance of the physical platform robot and Gazebo dynamic platform robot is required to be consistent in the joint experiment,the structural errors and state errors of the Gazebo robot are corrected.In the joint experiment,the Gazebo platform robot and the physical platform robot used the same set of programs and parameters,and obtained the data curve of high fitting degree,indicating that the motion state of the simulated robot is highly consistent with the physical robot,and the research in this paper is realizable.