Research Of Off-axis Laser Cutting Mechanism And Its Focus Control System Of Laser Cutting Machine

Abstract of dissertation should be concise and clear,without comment and additional explanation.The content should include the purpose,method,result and conclusion,etc.,it is independent and self-containedThe advantages of laser cutting are better cutting quality,higher flexibility and cutting efficiency,has a widespread application in industry.To assure the uniformity of cutting quality in different cutting direction,the axis of laser beam must proper align with the axis of assistant gas(co-axial)in traditional laser cutting application.It will improve the cutting quality and efficiency significantly by using the off-axial technology.To assure the accuracy and efficiency of off-axial laser cutting process,a fast reaction driver with compact framework should be used to do the real-time controlling the relative position between the focal point of laser and the axis of gas.The paper describe the off-axial laser cutting area according to the theory of thermoplastics and fluid dynamics,and then establish the ANSYS model by heat conduction equation,turbulence models and multiphase flow for off-axis laser cutting,The gas flow field of the assist gas in the off-axial laser cutting process is studied,and the mechanism of the interaction between gas and plate is analyzed.According to the results of the simulation of the flow field,the influence of the off-axis distance on the distribution of the gas pressure,velocity and shearing stress of the flow field is analyzed,shows that the influence of the off-axis distance on the flow field structure of the nozzle exit to the cutting front upper end region and the cutting front end region of the flow field structure.The experiment was launched by changing the off-axial laser cutting parameter,finished the gap analysis between the experiment result and simulation result.Verify that the off-axial laser cutting is a way to improve the laser cutting quality and efficiency.The paper design a platform with electromagnetic driving base on the effectiveness of off-axial laser cutting.There are three sets ringlike and cylindrical permanent magnetic which distribute averagely in axial direction,and provide the return force for the platform.There are another three sets differential control electromagnetic in radial direction to provide horizontal driving force for platform,realize the moving in X?Y direction and rotating in X?Y plane.According to the parameter of the platform,finish the theoretic calculation?ANSYS and experimentation research separately for the electromagnetic and permanent magnetic on the off-axial laser cutting focal point control driving platform,confirm the mechanics character of the platform.Establish the dynamics model of the off-axial laser cutting focal point control system.Establish the fuzzy controller by Matlab and finish the simulation character analysis for the platform by Matlab/Simulink.Finally,finish the experimentation research on respond character?position control character and corner control character by the real time seamless link function of dSPACE1103/controldesk and Matlab/Simulink.Simulation analysis and experiment result prove the good steerable on the off-axial laser focal point control system,provide the evidence for the application of off-axial laser cutting technology.