Non-contact method and system for building cad models by integrating

Abstract

Method and system are provided which permits the very precise integration of high density data scans obtained from different part orientations through the use of Horn's method. The data may be obtained from a laser scanner or other methods for obtaining high density data such as Moire interferometry systems. The method and system use an artificial intelligence technique which permits the very precise determination of the dimensions of analytic features. In the preferred embodiment, the method uses a laser scanner to collect a fine grid of height (z) values of the workpiece. The part is scanned along lines with constant x or constant y. Before the part is scanned, several small reference features are added to the part if needed. These reference features may be small pieces of tape, or small metal washers. Then methods are used to find the precise location of the centers of the reference features. These locations provide the necessary input to Horn's method so local coordinate systems for each scan can be mapped to a single global coordinate system.