Machine vision systems in the metallurgy industry

We herein present a paper dedicated to machine vision systems used in the m etallurgy industry for process control. The four different stages (lighting , acquisition, processing and decision) of a machine vision system are brie fly recalled through various systems implanted in the steel industry. The m ain focus of the present paper is set on the control of surface treatment p rocesses. Surface temperature measurements being often a crucial point in t he process control, after having quickly presented noncontact temperature m easurements, two machine vision systems relying on temperature measurements are carefully described. The two controlled processes: the laser cladding and the high frequency welding of metallic pipes, ate presented, and result s as well as limits of the two systems are shown. (C) 2001 SPIE and IS&T.