Development Of Three-dimensional Scanning Galvanometer System For Large-scale Laser Welding

The traditional laser 3D welding technology usually uses the two-dimensional galvanometer scanning system which combines the z-axis mechanical guide rail of the platform to realize the three-dimensional welding,or uses the three-dimensional mechanical guide rail to realize the three-dimensional welding.The characteristic of the mechanical guide rail is that it can provide the scanning range of any size in three directions.However,with the development trend of product structure complexity and higher requirements for welding speed,the two-dimensional galvanometer welding technology can not meet the needs of future industry.In this case,a set of laser 3D welding control system is designed,which involves mechanical,optical,electronic,computer control and other disciplines.It is a new 3D processing technology.Using the computer to draw three-dimensional graphics,and then using the self-developed threedimensional control software to control the laser beam dynamic focus on the product surface for three-dimensional scanning,it can realize the three-dimensional welding of the product.On the basis of laser physics,a new laser 3D welding control system is studied in this paper.The system is mainly suitable for the application where the size of workpiece is less than 230 × 230 × 90 mm and the welding speed is required to be 10 ? 2000 mm /s.This paper starts with the traditional laser welding technology,introduces the current situation and shortcomings of laser welding technology,then introduces the concept of dynamic focusing,selects the optical path structure,and points out the advantages of using optical 3D scanning technology compared with the traditional guide rail technology.Then,the design of galvanometer welding system is carried out,and its motion model is deduced from the light path diagram of galvanometer system.Due to the image distortion caused by various errors of galvanometer system,a three-dimensional image distortion correction algorithm is designed in this paper.The control software of laser 3D machining is designed,which realizes the functions of reading and displaying 3D graphics file,editing welding track,parameter setting,laser control,etc.In addition,based on Open CASCADE technology,3D display function is added to the control software to facilitate workpiece positioning.Finally,the feasibility,stability and accuracy of the laser 3D welding control system are verified by the experimental data,which basically meets the design requirements,and points out the shortcomings,technical problems that need to be solved in the future.