Research On Precise Trajectory Planning Of Robot Welding

Under the background of industry 4.0 era,since the implementation of "China Manufacturing 2025" strategy,There is a rapidly development in China's manufacturing industry area.Meanwhile,"Machine Replacement" has been an irresistible trend.In China,most of low-end-intensive small and medium-sized enterprises,industrial robots are still not widespread,especially in the welding industry.This article studies the trajectory optimization of welding robot based on the prototype welding robot,aiming at improving the welding quality of welding parts.Particularly,welding robot has been widely used because of its standardization,efficiency and intelligence,which makes it a significant position in industrial robots.In this paper,doing the following research work:First,making briefly introduction about the RoboGuide simulation software of FANUC,selecting the needed model of welding robot,establishing the RoboGuide simulation environment,adding the welding gun model in software environment,setting the tool coordinate system scientifically.Secondly,building up three-dimensional modeling of the transformer by Solidworks software,importing the geometric model into Roboguide software,analyzing the control system of the welding robot and the welding transformer to make coordination and control for welding robot and the transformer.Thirdly,according to the mechanical structure of the welding robot prototype,establishing the connect rod coordinate system of welding robot prototype by using D-H parameter method to build up kinematic model of the welding robot prototype.By these,the positive solution of the welding robot was obtained by using closed solution method,and the inverse solution of the welding robot was further solved.Meanwhile,by setting up the characteristic coordinate system of the six-degree-of-freedom welding robot and planning of the move trajectory,studying the welding seam,welding spot and end welding gun of the welding robot,and making TCP point calibration of the welding gun to improve the positioning accuracy of the machine.Studying trajectory planning method of three times,five times in joint space and high order polynomial interpolation.Finally,focusing on research of five b-spline curve fitting method.Based on the specific welding robot track,researching for three times,five times polynomial interpolation,five times of B spline fitting curve fitting program.Applying with Matlab to simulate three kinds of trajectory planning method and get the trajectory of kinematics curves.It was found that the kinematic curve of joint trajectory which planned by the five-order b-spline fitting curve fitting method runs more smoothly,and I decided that five-order B-spline fitting curve method will be used for trajectory planning.At last,in this paper I will briefly introduce to use Roboguide software for off-line programming of welding robot,and introduce 3D models build in Solidworks software then transfer into Roboguide simulation platform software.Writing the off-line welding program,simulating its motion trajectory and generating the TP program,and loading the program into actual robot.Based on the trial run platform and the concluded data and analysis of trajectory planning,selecting typically weld line,simulating robot welding in real environment to prove the theoretical analysis and software simulations.Finally,it's also the argument for my conclusion that five-order B-spline fitting curve method has positive influence on robot welding.