Optical 3D coordinate measurements and applications

Non-contact digitization with optical image sensors permits the reproduction of complex free form surface structures with high accuracy in short time. The optical sensor--based on Moire techniques combined with triangulation methods--digitizes up to 300,000 point coordinates within one view. Large objects are typically scanned in steps by controlling the sensor's position with a handling system. The partially overlapping views are connected afterwards in the computer to describe the whole model. The point cloud is exported to CAD/CAM/CAQ systems, which are doing the surface oriented processing. Today's applications range from copy-milling and surface reconstruction up to quality control and assurance. Especially the processing of the large point clouds with several millions of points needs intelligent algorithms in data organization and surface fitting. More automatic processing results in relatively low quality of the reconstructed surfaces whereas highest quality is obtained with experience and more or less interactive manipulation.