To get the groove information included in the current signal sampled by the rotating arc sensor

the arc length mathematical model is provided first

the Morlet complex wavlet is used to analyse the welding arc length signal and give a band-pass filter.The result shows that the real part of the complex wavlet coefficient is propational to the welding seam deviation and the imaginary part is propational to the welding torch obliquity.Then the complex wavelet method is used to analyse the signal actually piked up by rotating arc sensor the effectiveness is verified by the experiment.Thus a new method to pick up the information got by rotating arc sensor is provided.