Research On Multifunctional Off-line Programming System Of Arc Welding Robot

With the propose of Industry 4.0,arc welding robots are playing an increasingly important role in welding production and manufacturing.Compared with traditional teaching,off-line programming technology for arc-welding robot has significantly improved both programming efficiency and accuracy,making it increasingly widely used in the industrial field.However,the mature and commercial off-line programming software is expensive in abroad,and the research on the off-line programming system of robot started late in China.That has not been widely used in actual production because of slight deficiencies.Therefore,aiming at the above problems,this paper designs an arc-welding robot off-line programming system by analyzing and studying the current mature off-line programming software,which is mainly composed of motion simulation,path planning and arc welding control function modules.The details are as follows:Firstly,the overall structure and basic functional framework of the robot off-line programming system are designed,and the development platform of the off-line programming system is determined.Then,the research method and implementation approach of each functional module are designed.The kinematics of the robot is studied.The six-axis robot linkage model and forward kinematics is established by the modify DH parameter method,and the inverse kinematics equations of the robot are solved.The accuracy of the kinematics equation is verified by MATLAB and Robot Studio.In addtion,Aiming at the motion simulation,the trajectory planning algorithm of the robot is studied in the joint space,and the coordinate transformation relationship between the welding seam trajectory and the end of the welding gun is solved,which lays a foundation for the realization of the subsequent off-line programming system.Based on Visual C# platform and Open GL graphics interface,the visualization of arc-welding robot in virtual environment is realized by studying the reading and display method of STL three-dimensional model.On this basis,the interactive function design in simulation environment is completed by computer graphics.Then,the robot motion simulation is realized by combining the robot kinematics equation and trajectory planning algorithm.By analyzing the DXF entity structure,the workpiece trajectory is extracted and the coordinate information required for robot operations is automatically generated.For the complex curve welding seam of the intersecting line,the optimal welding gun pose was solved by establishing a mathematical model,and the construction of the characteristic coordinate system of the intersecting line welding seam was completed.Then,based on the RAPID programming language of ABB robots,a post code conversion function was designed to convert the welding trajectory into a program that the robot can recognize directly,achieving automatic generation of welding paths and robot programs.Finally,an arc-welding control module was developed through the PC SDK,achieving real-time monitoring and control for the robot.Using Robot Studio as the verification platform,various functions of the system were verified through conventional and intersecting welding seams.The results showed that the off-line programming system in this paper is effective and reliable,and can be applied to different welding tasks.