DETECTION OF IRREGULARITIES IN A CONVEX SURFACE, SUCH AS A TIRE SIDEWALL, USING BAND-PASS FILTERING

摘要

A device for the contactless detection of a potentially existing essentially edge-free irregularity in a convex surface, which has a structuring that is delimited by edges, comprises a unit for creating a three-dimensional representation of the surface, a unit for extracting the convexity from the three-dimensional representation of the surface and for smoothing the edges of the structuring so as to obtain a convex-free representation of the convex surface which exhibits the irregularity and the structuring, whose edges have now been smoothed, a unit for comparing the convex-free representation with a threshold value so as to identify areal regions of the convex-free representation which are determined by a predetermined relationship to the threshold value, and a unit for analyzing the areas of the identified regions, a region being detected as an irregularity if its area exceeds a predetermined area. When this device is used to carry out quality control of tires, bulges or constrictions can therefore be identified with certainty in real-time operation and can be distinguished from an inscription or marking which has been intentionally provided on the tire.