Research On Coordinated Welding Of Dual-arm For Interior And Exterior Decorations Of Auto Door Panels

In the welding production line for interior and exterior trim parts of automobile door panels,in the face of different types of automobile door panels and a large number and variety of welding points,it is necessary to make welding production more flexible and intelligent.Using dual-arm collaborative welding to replace single-arm welding can improve work efficiency,and also puts forward strict requirements for production safety: to ensure that dual-arm welding is a collision-free process.The preparation work before welding involves the two main issues of welding spots assignment and welding spots sequence planning,which are related to production welding efficiency.Therefore,this article focuses on the coordinated welding of dual mechanical arms for the interior and exterior trims of automobile door panels,and studies the coordinated welding of double arms,welding spots allocation and welding spots sequence planning.The main research contents are as follows:First,the kinematics and modeling of the welding robot arm are studied.Aiming at the problem of coordinated movement of both arms,it involves the kinematics of the robot arm.In this paper,the IRB1600 model manipulator is taken as the research object,based on D-H representation and iterative numerical solution,the forward and inverse kinematics equations are established,and the kinematics model is established.Based on the robot simulation platform V-REP,simulation experiments were conducted to verify the effectiveness of the robotic arm model,and the forward and reverse kinematics equations were verified.Secondly,the dual-arm collision detection and obstacle avoidance motion planning are studied.Based on the OBB(Oriented Bounding Box)enclosure technology,this article establishes a collision detection model for the robotic arm,introduces the collision detection algorithm based on the OBB-Tree overlap detection principle,and uses it as a collision detection basis for obstacle avoidance motion planning.The RRT(Rapidly-exploring Random Tree)algorithm is improved by setting the target offset probability,adding the minimum step control and introducing a bidirectional expansion tree mechanism,and applied to the robot arm obstacle avoidance path planning.Based on cubic B-spline curve algorithm,the path of obstacle avoidance path is smoothed to meet the smooth movement of the robot arm.In order to solve the collision problem of the coordinated movement of the dua-arm,this paper uses the master-slave idea to decouple the planning to prevent the dual-arm from colliding in the overlapping workspace.The above methods and measures are all simulated experiments under the V-REP platform.Finally,the welding spots allocation and welding spots sequence planning for automobile door panel welding are studied.This paper analyzes the actual welding production process requirements,and abstracts the actual problem description into a mathematical problem to solve.The problem of welding spots assignment is abstracted as a convex function optimization problem with constraints.The convex optimization method is used to solve the problem of welding spots assignment for automobile door panels.The welding spots sequence planning problem is abstracted as a TSP(Travelling Salesman Problem)problem with constraints,and it is solved using an improved genetic algorithm.In this paper,a dual-arm welding system simulation platform is built under the dual platforms of V-REP and Matlab,and the dual-arm welding experiment is performed using the results of the dual-arm coordinated motion,welding spots allocation and welding spots sequence planning.The experimental results show that the welding system can be effective,complete welding work safely.