For the fast three-dimensional acquisition of surfaces Fraunhofer EZRT is mainly employing light-section techniques. This technique is very advantageous for moving objects. Extensive knowledge is present for applications for tire manufacturing, the testing of mounted tires and wheels and the inspection of sealing rings for braking systems.
In light-sectioning a light-section is projected onto the object and this light-section is then recorded by a camera positioned under a different angle from the projection direction. From the course of this light-section a height profile is generated. By moving the object through the light-section the entire surface can be acquired. Shadowing effects can be overcome by applying multiple cameras or lasers.
Light-sectioning is especially suited for the fast three-dimensional acquisition of the surface of a specimen. Even when a lateral resolution of 0.05 mm is required, velocities of about 1 m/s are possible, with the height resolution then being in the µm regime. By applying suitable preprocessing, structures with a height deviation below 1 µm can be detected.