Research On Galvanometer Scanning System And Automatic Positioning System Of UV Laser Marking Machine

With the development of industrial products to miniature and lightweight,the size of the outer edge of cable,as an important accessory,gradually decreases while achieving universality,while the traditional ink-jet marking method is difficult to accurately mark effective information in a limited space.Ordinary laser marking device can carry out laser marking in a small range,but it is difficult to ensure the marking quality of high-speed flight marking.Therefore,in order to improve the accuracy of cable flight marking,this paper studies the galvanometer scanning system and automatic positioning system,and designs a laser marking system suitable for high-speed cable flight marking.Aiming at the difficulties of small processing range,fast transmission speed,and large manual focusing error for different types of cables during cable marking,There proposes a design scheme of UV laser marking machine,focusing on the research of galvanometer scanning system and automatic positioning system,and selecting the main functional components.The automatic positioning system focuses on the two parts of automatic focusing and accurate positioning of flight marking state based on eccentric beam method with linear CCD sensor as the core.According to the workflow of the galvanometer scanning and automatic positioning system,design the control system structure of FPGA and DSP joint control,and the FPGA microprocessor suitable for high-speed parallel control processing is used as the main control chip of the galvanometer scanning system;select the DSP that is good at floating-point arithmetic The chip serves as an auxiliary controller for image processing of the auto-focusing spot and then designs the main functional circuits of the control system.Considering the influence of positioning accuracy on the quality of printed image,the distortion of printed image is corrected from the aspects of focusing error,composite distortion error,nonlinear error,system error and flight marking error,which effectively improves the clarity of printed image.According to the design scheme of the galvanometer scanning and automatic positioning system,the performance of the galvanometer scanning motor servo system is simulated and analyzed by MATLAB.The simulation model of scanning motor based on Stribeck friction model is established in Siumlink module.The current-speed-position loop servo control system based on compound control strategy,pseudo differential negative feedback control(PDFF)strategy and fuzzy adaptive PID control strategy is designed to ensure the stability of the system and improve the response speed of the system to 28.8 μs,and verify the deflection speed and position tracking performance of the scanning motor.Then,the upper computer software of the laser galvanometer scanning control platform is designed,and the design scheme of this paper is verified through static marking experiment,cable flying marking experiment,and auto-focusing experiment,which proves the rationality of the design scheme.The experimental results show that for cables of different sizes,fast and accurate marking can be achieved by adjusting the parameters in both stationary and flying marking states;while the autofocus system can achieve a focus accuracy of 4μm within a dynamic focus range of ±240μm.Based on improving the degree of automation of the laser marking machine,the purpose of clear marking on the surface of the cable in the flight state is realized.