| Since the 21 st century,with the development of science and technology,China has transformed from a manufacturing power to a manufacturing power.As an indispensable material processing technology in manufacturing,welding is widely used in small and medium-sized enterprises.For enterprises to replace manual semiautomatic welding or robotic welding,it can undoubtedly improve their own efficiency and gain greater competitiveness.However,the process of automatic welding itself does not exceed manual welding.With the increase of welding speed,the weld will gradually show defects such as undercut,hump,and discontinuous weld formation.At the same time,due to the processing error of the welded workpiece Or the positioning and assembly deviation of the workpiece to be welded on the positioning tooling.When using robot teaching for welding,problems such as welding deviation and uneven welding may occur.Therefore,automatic welding is often difficult to achieve good forming results.Based on the above problems,this paper carries out the high-speed GMAW weld identification and process research based on the composite magnetic field arc sensor.The specific research contents are as follows:(1)Based on the control effect of the magnetic field on the arc,the motion mechanism of controlling the arc gathering and swing deflection under the action of the compound magnetic field is analyzed,and the mathematical model of the magnetic field at each point in space under the action of the compound magnetic field is deduced,and then the structure of the compound magnetic field sensor is designed.,the specific parameters of a magnetic field generating device with an external magnetic field are determined,and finally,the influence of different structures and parameters on the magnetic field distribution in the arc working area is analyzed through simulation,and the structure of the sensor is optimized.(2)Use simufact welding to establish a heat source model under the action of a compound magnetic field,and simulate the welding process of the swinging forward arc under the action of the compound magnetic field and compare it with the condition without a magnetic field.The results show that the swinging forward arc makes the highest temperature field also follow the arc.When a certain offset occurs,the heating radius of the arc becomes larger,and the width and depth of the molten pool increase compared with the normal welding conditions,and the heat transfer in the molten pool is more uniform.(3)A composite magnetic field high-speed GWAM weld identification system and experimental platform were built,and high-speed GMAW welding experiments under different excitation parameters were carried out.During the experiment,a high-speed camera was used for image recording.The results showed that: under the action of the composite magnetic field,the arc was A certain amount of aggregation occurs under the longitudinal magnetic field,and with the increase of the excitation parameter in the transverse direction,the arc gradually deflects in the welding direction,and the hump and undercut of the weld gradually disappear.It is further verified that the composite magnetic field can significantly improve the high-speed GMAW weld formation.Finally,the limiting average filtering algorithm is introduced into the filtering optimization of the original current waveform data,and it is found that the filtering algorithm can effectively perform peak filtering and low-frequency filtering.A relatively clear weld waveform data was obtained. |
