Off - Line Programming And Simulation Of Welding Saddle - Type Welds For Arc Welding Robot And Positioner

With the advancement of modern industrialization level, the development of industrial automation manufacturing technology which is mainly based on robot has became a trend.The paper makes the following aspects of research for the arc-welding robot unit,which consists of MOTOMAN-UP6 robot and 2R rotary dumping positioner:(1)The kinematics problems of MOTOMAN-UP6 arc-welding robot has been researched.Firstly, by analyzing the structural characteristics of arc-welding robot,the author has used solidworks software to build the UP6’s three-dimensional partly model and form the assembly model.Then by using the modified Denavit-Hartenberg parameters of arc welding robot to analys and describe linkages,which are set up coordinates in each of the robot’s links,the author has described the relationship between the movement of each links by a homogeneous coordinate transformation matrix. Finally, by the example defined a group of joint’s angle, the kinematic equations has been compared with the end of physical model’s position and orientation in order to verify the correctness of the kinematics equations.During calculation of robot’s kinematics, the forward kinematics solution process of UP6 has been programmed into the MATLAB M-file function straight.m. Through to set angle values for each the shaft axis, to get orientation matrix which is the position of the welding gun’s end center relative to the based coordinate system.(2)For the typical space saddle of intersecting welding curve,welding seam feature model has been built.Using the discrete method of average arc-angles, and calculate the welding track points each curve tangent axis and the tangential direction normal plane with large and small pipe lines which cross the track points in the locus of points by the geometric formulas,which is to build each track point feature coordinates.When you define a attitude of welding seam building based on the gesture-description method of ZYX euler angles, and this will be as a factor affecting the quality of the welding process to consider, as a basis for planning the welding process perspective.(3)The thesis has infered the solution of kinematics inverse for the positioner based on the building angle of welding seam,by analysis of structural features for positioner, and built the model of positioned to infer the kinematic transformation equations.Finally, according to planning requirements of the welding seam building angle, the inverse solution equation for positioner is derived to obtain the inverse solution formula for positioned meeting the ship-welding.(4)Robot and positioner coordination saddle-shaped curve seam welding offline programming software RoboticFace based on MATLAB GUI and Robotics Toolbox has been developed. This paper introduces the design ideas of the software from the layout of software’s interface,then focuses positioners coordinating displacement module, robot coordinate tracking module, file output module, environmental unit layout module and weld setting module to describe in detail, and provides the module codes.(5)The article has adopted the RoboticFace to calculate separately each axis angle of arc welding robot at a fixed station stably weld saddle seam and welding robots and positioner coordination weld saddle seam,then using solidworks to take motion simulation, and focuses on end track, the angular displacement of each axis, angular velocity and angular acceleration to do comparative analysis.Weld angles get arc welding robot with welding positioner coordination weld saddle has meet the flat welding(ship-welding), and in fixed station stable saddle seam welding, weld angles obtained the pitch angle and rotation angle are unstable weld angle, which will affect the welding quality and welding appearance.(6)Finally, the author has finished the Motoman-UP6 arc welding robot and 2R spin-tilt positioner coordinated welding saddle-shaped space curve tests.The axis angle of the eight-axis get from coordination welding saddle seam by the RoboticFace software.Through the various discrete points corresponding to eight joint axis angle interpolation defined,the off-lineprogramming process has been accomplished.Welding test procedure is satisfied the pose requirements of the saddle seam welding ship.At the same time,it is satisfied the pose torch angle setting process,eventually it reachs the actual welding needs.