Patent ID: 9036893
Filing Date: 2015-05-19
Classification: G01B,G01M,G01N,G06K,G06T

Abstract:
1. A tire defect detection method for detecting a convex defect in a contact area of a tire comprising tread pattern elements, comprising: a shooting step of successively shooting two-dimensional images of an area of the tire including a region irradiated with slit light by irradiating a tire tread with the slit light so that a longitudinal direction thereof becomes parallel to a width direction of the tire, while rotating the tire about a predetermined axis; an extraction step of removing, from among light images of the slit light appearing in respective shot two-dimensional images, a light image other than linear light images which are light images of the contact area of the tire and extracting the linear light images; an eliminating step of eliminating an influence of displacement of the contact area resulting from the rotation of the tire, from the two-dimensional images including the extracted linear light images; a calculation step of calculating a difference between a position of the linear light image in each of the two-dimensional images from which the influence of displacement is eliminated and an average position of linear light images in all two-dimensional images from which the influence of displacement is eliminated as a feature quantity for each of the two-dimensional images; and a detection step of comparing a calculated feature quantity for each of the two-dimensional images and a predetermined threshold, and in a case where the feature quantity is larger than the predetermined threshold, determining that the tire has some defect.