Shape verification aimed for manufacturing process control

We describe a method to verify the shape of manufactured objects by using their design model. A non-contact measuring method that consists of a stereo-camera system and a single projected fringe pattern is used. The method acquires one image from each camera. Additional shape information from the design model is also used. This surface-measurement method gives an accuracy of about 45μm. Deviations from the design model within ±1.6 mm can be correctly detected. The measured surface representation is matched to the design model using the ICP-method. Fast performance has been considered adapting the method for on-line use.

Research Highlights
► A shape measurement method aimed for verification in on-line adaption using projected fringes is discussed.
► The discussed shape measurement method is based on one single pattern recording which makes it insensitive for vibrations. It makes use of the expected shape represented by the design model for the object.
► We compare the measured shape with the design model. An experiment where depth differences in milled off traces for an object is measured.