Research On Automatic Focusing System Of Laser Marking Machine Based On Image Processing

The new laser processing equipment,represented by the laser marking machine,is becoming more and more widely used in all walks of life.The pattern and text information are engraved on the surface of the workpiece by laser focusing.The marking quality is closely related to the position adjustment of the focus.The traditional manual adjustment method has large error.It can effectively improve the adjustment precision and increase the flexible operating space of laser processing.Based on this point,a automatic focusing system of laser marking machine based on image processing is designed,and the system is implemented step by step.First,the structure and working principle of the laser marking machine are briefly introduced,and the idea of using the CMOS camera to collect the image is put forward,and the implementation scheme of the auto focusing system is introduced and analyzed.Secondly,by collecting image data,and briefly analyzing and verifying the feasibility of the scheme.Through MATLAB software,the image is processed with gray level,two value conversion,image cutting,wavelet denoising,target extraction and so on.Finally,the function relationship between the focus height of the laser and the number of target pixels is obtained.At last,the host computer communicates with the MCU by controlling the serial port,and drives the stepper motor to control the lifting platform of the wire rod,so that the laser focus is displaced to the surface of the object,and finally the working process of the whole automatic focusing system is completed.A series of problems presented in this paper are tested and simulated,including the correction test of the distortion of the scanning galvanometer,the image acquisition and test,the algorithm simulation of the wavelet denoising,and the control test of the MCU and the stepping motor using simulation software.According to the analysis of the result,the optimal image acquisition scheme is selected,and the test results of the image wavelet denoising meet the precision requirement,and the feasibility of the automatic focusing system based on the image acquisition is verified.