Research Of Pipeline Robot Based On Metamorphic Mechanism

Because of their own structural limitations,most pipeline robots can only pass through a single type of pipeline,such as a single straight pipeline or curved pipeline,but have no ability to pass through three-way or four-way pipeline sections at present.In this paper,the concept of metamorphic mechanism is applied to the fuselage structure of the pipeline robot.Based on the characteristic that the metamorphic mechanism structure be transformed,a metamorphic pipeline robot with symmetrical structure is designed to ensure the robot can get through three-way pipeline section and horizontal four-way pipeline section.The research contents of this paper are as follows:(1)Structural design of metamorphic pipeline robot.The working conditions of the pipeline are analyzed to plan the working principle of the pipeline robot.To design the fuselage structure of the pipeline robot metamorphic mechanism,the configuration states required for the robot to pass through different pipeline sections are analyzed.And topology diagrams and mathematical formulas are using to describe the two configuration states of the pipeline robot fuselage.Then the adjacency matrix binary algorithm is used to analyze the pipeline robot.According to above results,the three-dimensional model of the pipeline robot is established by carrying out the configuration transformation description.(2)Kinematic analysis of metamorphic pipeline robot.The forward kinematics model of the robot body is modeled by the Poe exponential product formula of the screw theory,which is compared to another kinematics model that is established by the D-H parameter method to verified its accuracy.Based on the screw theory,the Jacobian matrix of the robot body velocity is established,and its correctness is verified by ADAMS simulation,which further proves the feasibility of the application of the screw theory in the kinematic analysis of the metamorphic pipeline robot.Using Matlab-Robotic Toolbox to analyze the kinematics of the robot fuselage model,and apply the quintic interpolation polynomial to plan the space trajectory of each joint of the robot fuselage.(3)Dynamic analysis of metamorphic pipeline robots.On the basis of kinematic analysis,the simplified robot dynamics equations are established by the Newton-Eulerian dynamic equations to solve the joint torques.The virtual prototype of the robot is established by ADAMS dynamics simulation software,and the time-dependent torque curve of each joint under different centers of mass is solved by the virtual prototype.(4)Metamorphic pipeline robot control system design and pipeline passing experiment.The pipeline robot control system is developed in the ROS system,and then the communication between ROS and Arduino is established to realize the control of the physical prototype.Finally,by using 3D printing technology,a physical prototype of the metamorphic pipeline robot is made and the T-shaped vertical three-way and horizontal four-way pipeline passing experiments were carried out.