Research On Automatic Trajectory Planning Of Welding Robot Based On STEP

With the application and development of industrial robots in the fields of automobile manufacturing,machining,welding,loading and unloading,grinding and polishing,palletizing,assembly,spraying and other fields,the traditional online display teaching of industrial robots cannot meet the needs of complex and efficient production.In order to meet the needs of accurate and efficient production in modern industry,researchers pay more and more attention to the offline programming technology of robots.As a task-oriented programming method,offline programming can effectively improve the programming efficiency in the actual production environment.In this paper,the offline programming technology of MARK III LNG marine stainless steel polyhedron workpiece for robot’s stud welding and arc welding is studied.Aiming at the problem that the robot needs to be taught online again after the parts are replaced,this paper introduces a method for automatically generating welding programs for arc welding robots.Aiming at the MARK III LNG marine stainless steel polyhedron workpiece model,the process and algorithm of data extraction for stud welding and arc welding are given to complete feature parameter extraction.And write a program to read the STEP file to automatically extract the key information to prepare for subsequent trajectory planning.The program has certain generality.This paper introduces the vector to describe the robot’s attitude,transforms the robot’s attitude transformation into rotation between vectors,and then indirectly determines the robot’s attitude coordinates.The D-H model of the MOTOMAN robot was constructed to solve the forward and inverse kinematics of the robot,and a calculation method of bipartite vector approximation was designed to adjust the robot to the optimal posture to ensure that no singular points appeared during the welding process.Combine the extracted coordinate information with the calculated robot pose to form a robot trajectory,and automatically analyze the JBI file format to generate a robot job file.Off-line programming experiments are performed on workpieces of different sizes,which proves that the method and software tool developed by this article to extract information from STEP files and generate robot processing trajectories is effective.Based on the developed offline programming software,a MARK III LNG marine stainless steel polyhedron robotic automatic workstation is designed to maximize the efficiency of the robot and quickly and easily realize the part replacement.