Study On Signal Processing Of Automatic Tracking Seam Of Fillet Rotating Arc TIG Welding

With the development of science and technology,the requirement of welding quality in industrial production is constantly improving.The automation of welding process has become an inevitable trend.TIG welding(Tungsten Inert Gas Welding)is widely used in various important welding occasions because of its high welding quality.Welding wire filling is necessary for many large structural steels in industrial production.The study of TIG welding seam tracking with filler wire is helpful to improve the quality and efficiency of large structural steel welding.Rotating arc sensor is an excellent welding sensor.Many achievements have been made in the research of automation of rotating arc MIG welding(Melt Inert Gas Welding).In this paper,the rotating arc sensor is applied to TIG welding,and the signal processing of automatic seam tracking in TIG welding with wire-filled rotating arc is studied,which lays a foundation for the practical application of automatic seam tracking in TIG welding with wire-filled rotating arc.In this paper,the research status of weld tracking system at home and abroad is introduced,and a TIG weld tracking system with filler wire rotating arc is designed.According to the process flow of TIG welding,a seam tracking platform is built.Through theoretical analysis and welding experiment,the signal model of TIG welding with filler wire rotating arc is established.The filtering method,deviation identification method and motion control algorithm of TIG welding with filler wire rotating arc are studied.Firstly,the TIG seam tracking system of filler wire rotating arc is built.The welding seam tracking system uses TIG welding rotating arc sensor to detect welding seam information,and collects welding electric signal by card.The actuator of the seam tracking system is the cross slide mechanism of the guide rail.The motion control card and step motor are used to control the torch movement.Aiming at the characteristics of rotary arc TIG welding,the protection circuit is designed and the signal acquisition process is analyzed.In this paper,the scanning height model of rotating arc,the commonly used welding filtering method,the deviation identification method of rotating arc sensor and the motion control method are studied.Aiming at the influence of filling wire on rotary arc TIG welding,the arc height model of rotary arc TIG welding was analyzed.The welding process of back filling wire was determined according to the actual signal of rotary arc TIG welding with filling wire.According to the analysis of TIG welding signal in frequency and time domain,a filtering process combining digital low-pass filter and wavelet filter is designed.According to the characteristics of TIG welding electric signal,the deviation identification method of characteristic maximum method is determined,and the correct deviation of weld is obtained by correcting the initial position of optocoupler.For the control of seam tracking,the PID motion control and intelligent control methods are analyzed,and the expert PID control method and the PID control method are used to control the horizontal and vertical deviation respectively.In this paper,the actual effect of the seam tracking system is tested by V-type weld welding,which can meet the requirements of seam tracking.