Abstract: With interferometric test systems, the test object is frequently measured over several sections in order to realize a complete test. If special structural features are found, in particular defects, it is usually difficult to localize the structural features shown on the result images on the object. It is the object of the present method to transfer the interferometrically measured data from the various sections to a joint object coordinate system. To achieve this object, the shape of the object is measured and the spatial coordinates for the deformation data on the object surface are determined from this measured. Thus, a method is realized which permits determining the exact spatial orientation and position of the discovered structural features on the object. On the one hand, the defects on the object can thus be localized precisely while, on the other hand, an exact quantitative evaluation of the results is possible.

Abstract: An apparatus for testing tires performs the following steps: rotating the tire relative to a camera; projecting light sections on a tire surface; capturing projected light sections by the camera at defined rotary positions of the tire relative to the camera; applying signals representing the captured projected light sections to an image processing system; determining the shape of the captured projected light sections by the image processing system; determining the shape of the tire surface from the shape of the captured projected light sections; repeating the above steps for different inflation pressures of the tire; and comparing the determined shapes of the tire surface for different inflation pressures of the tire for determining shape changes of the tire due to changes in the inflation pressure.

Abstract: A method and a measuring system capable of real-time pickup of deformation images of a surface of a test object is provided. A plurality of mutually phase-shifted interferograms are generated. From these interferograms, a normalizing mask, which is stored in memory as a normalization data set, and a reference imageare generated. Next, each speckle image generated is processed with the reference image to form a differential image that is linked with the normalizing mask. The normalizing mask can include a data set with pixel-specific normalization data. The pixels of the differential image are then divided by the respectively associated values of the normalization data set in order to generate a normalized stripelike image of the deformed surface.

Abstract: Optical methods for the testing of component areas by using interferometric techniques or processes using structured light, which compute the deformation of the object by means of the picture processing and display the result as a phase difference picture are known. The structure-dependent local deformations are frequently superimposed by whole-body movements or other non-relevant global object deformations, which make it difficult to recognize local structural features, particularly structural defects. With the new picture processing method, the phase difference picture is manipulated in such a way that the local structural features are removed. This manipulated phase difference picture is subtracted from the original phase difference picture, so that a phase difference picture results, which shows only the local deformations.

Abstract: A measurement system is used in particular to detect defects in test objects. To that end, the test object is lighted from a lighting unit that includes a plurality of laser diodes. The beam cones of the individual laser diodes generate a common lighting spot on the test object. The object being measured is observed interferometrically, where the interferometer is part of a measurement head. An electronic pattern sensor detects interference patterns generated by the interferometer.