Research On The Dynamics Of HDPE Film Welding Robot System Based On Bond Graph Theory

At present,high-density polyethylene film(HDPE)is widely used in anti-seepage projects such as landfills and reservoirs,and is the core component of the main antiseepage structural layer.However,due to the continuous influence of long-term corrosiveness and high load in the environment,HDPE film is very easy to break,and if it cannot be repaired in time,it will bring great threat to the surrounding environment and groundwater.In order to solve the above problems,this topic proposes a new parallel welding robot system,which organically combines parallel mechanism and thermal fusion welding technology.This robotic system is studied from the viewpoint of kinematics,dynamics modeling,vibration response and prototype experiments,and the main research contents are as follows:Design of HDPE film welding robot system solution and kinematic analysis of its parallel mechanism body.For the structural layer composition of the operating landfill,design a scheme of HDPE film parallel welding robot system suitable for the above environment;establish the kinematic forward and reverse solution model of the body of the parallel mechanism in the scheme and derive the kinematic parameters required for the subsequent dynamics model;determine the size of the parallel mechanism workspace based on the kinematic inverse solution.To build a coupled dynamics model of the parallel welding robot machine,electric and thermal multi-energy domain.First,the bond graph is used to establish the bond graph model of the drive motor and the hot air welding gun;second,a parallel mechanism body dynamics model is established using the screw bond graph to obtain a fully solved dynamics model of the electromechanical and thermal multi-energy domain system;finally,given the weld execution trajectory,the multi-energy domain coupled dynamics model is solved by MATLAB equation of state,ADAMS dynamics simulation and 20-sim bond graph simulation The validation analysis is carried out.Considering the elastic deformation of lightweight members,a rigid-flexible coupling dynamic model of the parallel mechanism was established.For flexible link distributed parameter systems,a modal vector bond graph is defined based on the hypothetical modal method,and a modular bond graph model of flexible link elements is constructed using the screw bond graph.The global dynamic model of rigid flexible coupling is obtained,and the state equation of rigid flexible coupling is derived;Conduct modal analysis and forced vibration analysis on the established rigid flexible coupling model through ADAMS to obtain its amplitude frequency characteristics and phase frequency characteristics,verify the simulation accuracy of the rigid flexible coupling bond graph model,and provide theoretical reference for subsequent vibration analysis.Vibration simulation analysis of a rigid-flexible coupled parallel mechanism system.Firstly,based on the 20-sim bond graph simulation model,the parameters of the motor control system are tuned,and the coupling vibration interactions between the control subsystem and the mechanical subsystem are discussed in the frequency domain;Secondly,the coupling vibration of the control subsystem and the mechanical subsystem is analyzed through 20-sim software,and appropriate controller parameters are selected;Finally,an experimental platform was built for experimental research on motion trajectory tracking control.