Robot Welding Off-line Programming And Welding Process Of Aluminum Alloy Space Welds

With the continuous development of welding robot technology,welding robots are widely used in the actual welding of space weld,such as the welding of pipe-tube,tube-ball,tube-plate and other intersecting lines weldin,spherical tank welding,pressure vessel welding,oil platform pipe pipe welding and so on.However,in the current production process,the welding robot is still based on online instruction programming,and the complexity of the parts and the particularity of the environment put forward the strict requirements for the programming of the welding robot,and the robot off-line programming technology has made up the shortcomings of the online teaching programming with its many advantages.This paper introduces the description method of position and attitude of space object and the way of transformation between space coordinates.According to the intersecting line model,the mathematical equation of intersecting line is derived,and the position and attitude model of space welding seam and welding torch is established.According to the welding characteristics of the fillet weld,the calculation method of the ship shape welding angle is given,and the KR60 HA robot connecting rod coordinate system is established by D-H method,and the method of solving the positive and inverse kinematics is derived.Using KUKA SimPro and KUKA OfficeLite software,the off-line programming workstation of KR60 HA robot is constructed.According to the ship shape welding angle,the CIRC motion instruction was used to edit the coordinated path program of the intersection line of the KR60 HA robot and the positioner.At the same time,the simulation of the running track,the collision detection and the generation of the program files were realized.The joint angle changes of the robot before and after the trajectory planning are compared,and the joint space planning method can effectively solve the problem that the A4-A6 joint angle of the KR60 HA robot varies greatly on the one fourth solder joint of the intersecting line.The deviation between the coordinate system of the virtual working environment and the coordinate system of the actual working environment is analyzed,and a calculation method for solving the actual coordinate values is given on the basis of the ideal state.The computation results of this method are almost the same as those in the software.By this method,the off-line programming efficiency of KUKA SimPro is effectively improved.The influence of welding parameters and robot running trajectory on weld formation of intersecting line is studied.When the MIG current is 135 A and the average welding speed is 498.5mm/min,the workpiece has been burnt-through on the three fourths of the intersecting line.When the MIG current is 128 A and 120 A,and the average welding speed is 608.3mm/min and 629.5mm/min respectively,the defects such as incomplete fusion,discontinuous weld and unfilled pool appear at the beginning,one fourth and final stages of the intersecting line weld;When the MIG current and the average welding speed are 120 A and 629.5mm/mim respectively,the intersecting line welds obtained by the planned running track program are continuous and have a more uniform ripple.