Rotating arc sensor is an important sensor for automatic weld seam tracking.In order to obtain the characteristics information of groove weld of underwater welding

the welding current signal must be denoised so as to remove interference information.Plane median filter is used to deal with the noisy points of eight directions

and smooth filter is used to process the singular point and the burr of current signal

as well as wavelet transform can achieve separation of signal and noise so as to clearing up the noisy signal in the entire range of frequency domain.A new filtering method is designed

which is integrated by plane median filter

mean filter

smoothing filter

morphological mean filter and improved wavelet filter.The result of simulation using Matlab indicates that this method is very effective to eliminate various kinds of interference signal which is produced in the welding process

and the signal manifests the law of sinusoidal variation after signal processing.Through the welding experiments

the effect of weld seam tracking is great.