Research On Fiber Laser Welding Robot System And Its Applications On Turnstile Of The High-speed Railway

Due to the complex welding track,high market demand and high welding accuracy requirements,a processing method with high production efficiency and high qualified rate has not been found for the turnstile of the High-Speed Railway.Based on the welding difficulties and requirements of the turnstile of the High-Speed Railway,a set of optical fiber laser welding robot system has been designed,and the welding experiments on high-speed railway turnstile have been carried out.The main studies of this paper are as follows:(1)The whole structural design of the fiber laser welding robot system has been designed.The Huashu robot was chosen,while fibre laser and vision sensor were used as the core part of the welding system.The robot is equipped with a 6KG load,and its maximum working radius is 1550 mm.As for the vision sensor,the working distance is 52-63 mm,the detection width is 10 mm,the sampling frequency is 50 Hz.Meanwhile,the light source is supplemented with a blue line structure of light.The housing of the turnstile of the High-Speed Railway is 1000 mm long,28 mm wide,and 60 mm high.Also,the weld is a three-dimensional complex weld,which includes three angular welds with different angles.The housing is made of SUS 304 stainless steel splicing,and the material thickness is 1.5mm.The whole system can assure the stability of the system which controls the error within0.005 mm,thus improving the accuracy of the welding system.(2)The control design of the whole welding system has been completed.The industrial control machine was used as the upper computer of the whole control system,the I / O communication mode between the upper computer and the auxiliary system was designed.The RS-232 serial port communication mode has realized the communication between the upper computer and the laser.Ethernet port communication has realized the control between the upper computer and the intelligent industrial robot and visual sensors.In the end,it has realized the integration of laser welding robot linkage,which could be used in the actual production process,improving the production efficiency.(3)A welding position tracking system for the welding of the turnstile of the High-Speed Railway has been designed.The location and profile of the target were detected by non-contact measurements.The sensor is 86 mm long,50 mm wide,and 120 mm high.The internal COMS camera is fixed with the Blu-ray laser at certain angle,to make sure it is easy to brighten the weld seam and grab the weld images.The system has a resolution of 0.003 mm in height and a resolution of 0.005 mm in width,so the accuracy of the point-taking has been increased.The neural network model is built to complete the identification and positioning of the turnstile weld seam.(4)Optical fiber laser welding experiment and process optimization of the housing of the turnstile of the High-Speed Railway have been conducted.The optimal process parameters for laser welding of the material of the turnstile of the High-Speed Railway has been determined.The laser power is 600 W,welding speed is 16 mm/s while the defocusing amount is 1mm.The tensile strength under this process is 632 MPa.The welding experiments of control variables were designed separately for different welding process parameters.The effect of laser power,welding speed and defocus quantity on the welding quality of the turnstile of the High-Speed Railway were obtained.Simulated welding experiments on the turnstile of the High-Speed Railway were performed by using ANSYS.According to the actual welding experiments,the welding procedure of the turnstile of the High-Speed Railway was gained: laser power 1000 W,Welding speed 24 mm/s and defocus 0mm.At last,the model of the BP neural network was established to optimize the welding process,whose parameters are: Laser power 1000 W,welding speed 20 mm/s and defocus 0mm.To some extent,the degree of independent research and development of optical fiber laser welding robot technology,the efficiency and the quality of the manufacturing of stainless steel products and the transformation of manufacturing industry to intelligence can be improved by this research work.