Detection of Weld Line and Gap Width Based on Analysis of Intensity Distribution of Scattered Laser Slit Light

Study on Visual Sensing System for In-process Control of Arc Welding Process (2nd Report)

Abstract

Detection of groove information such as gap center-weld line and gap width of groove by projecting vibrating laser slit-like light is shown based on the analyeis of intensity distribution of laser slit-like light reflected or scattered from the surface of two kinds of steel sheets, each involved gap width (0.1-1.0 mm) with I shape groove.
Intensity distributions of laser spot light and laser slit-like reflected light vary in space or time, but the intensity variation decrease nearly 50% by vibrating laser slit-like light. In addition, the intensity variation of laser light is influenced by the surface property of the object.
Detection. of gap center-weld line and gap width of I shape groove of specimen is based on sharp reduction of intensity of reflected light at root gap.
Furthermore, an algorithm for detection of weld line and gap width of groove has been developed and it's effectiveness has been proven experimentally.