Automatic surface inspection of metal tubes by artificial vision

The authors present in this article the different problems they have been facing with the design of an artificial vision inspection system for metallic tubes. They focus on the adopted solutions, the implementation of these solutions, and an estimation of the system performance in an industrial environment. The solution is based on the use of a set of linear CCD cameras. The displacement of the object under inspection ensures the achievement of a two dimensional image. The choice of two different points of view enables us to consider tint and embossing variations. The introduction of an angular correction reduces the scattering of the response due to the nonplanarity of the surface under control. The calculation of the parameters in a low level language enables us to perform a real time inspection (running speed: 1m/s [3.3 ft/s]).