Acquisition of deformed stripe images in height measurement of gas tungsten arc weld pool

A new method which was based on stripes reflection and fourier transform to measure the three-dimensional surface shape of the GTAW weld pool was proposed in this paper.The grating stripes was projected onto the weld pool surface using the laser.A double-lens system was set on the reflecting optical axis to transfer the weld pool surface and the arc was eliminated by spatial filter.Deformed stripes caused by the weld pool surface shape were reflected and interspected by an imaging panel placed on the output plane of the double-lens system.A CCD camera was used to observe the changes of the reflected deformed laser stripes on the imaging panel an real time.The effects of the torch position,reflection properties,arc radiation and other factors were analyzed to get the appropriate projection angle and system parameters.The result showed that the deformed stripe images obtained from the weld pool surface were clear and met the requirements of image processing.Finally,the surface shape of foreside weld pool was measured preliminarily.