Instrumentation and Measurement Method for the Inspection of peeled Steel Rods

This paper presents an optical method for the automatic inspection of the surface of peeled steel rods. After the peeling process the object is rotated in front of a light sectioning system, which acquires both the surface geometry and the intensity of the reflected laser light, respectively. The periodicity of the helical surface relief is determined from the auto-correlation of the intensity data. The surface relief can be extracted by a simple geometric model, and is reconstructed using a harmonic filter. Furthermore, an inline-inspection method is proposed that inspects the surface during the peeling process. All methods are demonstrated with real data from industrial steel probes measured under laboratory conditions.