SHAPE MEASUREMENT METHOD AND SHAPE MEASUREMENT APPARATUS FOR TIRES

Provided is a shape measurement method and a shape measurement apparatus for a tire in which the thickness of a tire can be measured around the tire precisely in a short time. Provided is a shape measurement method for a tire comprising: an outer surface and inner surface shape measurement steps in which, from image data of the outer surface and the inner surface, an outer surface shape data and an inner surface shape of the tire are detected; an outer surface and inner surface primary components extraction steps in which irregularities along the tire circumferential direction around the tire in the outer surface shape data and in the inner surface shape data are subjected to Fourier transformation to take out primary waveform components respectively; a circumferential position adjustment step in which the tire circumferential positions of both of the waveform components are adjusted to adjust the tire circumferential positions thereof; a cross section position adjustment step in which, from information about the placement angles and the positions of the first camera and the second camera, the tire radial direction cross section positions of the outer surface shape data and the inner surface shape data are adjusted; and a shape data synthesis step in which, based on the adjusted tire circumferential positions and the tire radial direction cross section positions, the outer surface shape data and the inner surface shape data are synthesized.