CAD-based Displacement Measurements with Stereo-DIC: Principle and First Validations

A new displacement measurement technique is proposed in a stereovision setup, which uses the object of interest as the support of the correlation process. This procedure leads to a global approach to stereocorrelation. The method is presented in its general formulation and is then particularized to the case of non uniform rational B-splines (NURBS). The displacement field is directly measured as a 3D field expressed in a NURBS basis consistent with the existing geometric model. The kinematic measurements are validated against prescribed displacements of a machined Bézier patch. The feasibility in an industrial context is shown with the analysis of 3D displacement fields of a 2- m 2 automotive roof panel during a welding operation.