OPTICAL VALIDATION OF PRECAST CONCRETE COMPONENTS

Abstract

Precast concrete components are complete structures of reinforced con- crete which are pre-manufactured in a factory and then delivered to the construction site ready-to use. These components normally ar- rive just in time and are directly incorporated into the construction on arrival. Because of that, falsely labeled components or deviations from the speci cation are very harmful as they are often recognized too late. To cope with this, the components are automatically detected in camera images and veri ed to 3D model speci cations of the required parts. To do so, distinctive parts or shapes of the detected component have to be matched between the image to the model to compute a 2D- 3D mapping. Afterwards, the shape and structure can be compared and veri ed. Multiple images of di erent views are necessary to com- pletely verify the structures. For this task, suitable feature detection algorithms is determined and implemented to compute 2D-3D corre- spondences. Afterwards, the pose of the camera is estimated and 3D points are projected to 2D. Finally, the shapes of the components in the 2D image and the 3D model is compared and veri ed; di erences are visualized.