Coordinate measuring machine and method for measuring coordinates of a workpiece

A method for measuring coordinates of a workpiece, the method comprising the steps of:

• (a) measuring first coordinates of a single point on a surface of the workpiece with a point measurement device arranged in a measurement head of a coordinate measuring machine, wherein the first coordinates are defined relative to the measurement head;
• (b) recording an image of a reference surface, wherein the reference surface is the surface of the workpiece or the surface of a component, whose position relative to the workpiece is unchangeable, with an area measurement device that is rigidly connected to the point measurement device;
• (c) displacing the measurement head and/or the workpiece such that the measurement head and/or the workpiece assume different relative positions with respect to one another;
• (d) repeating steps (a) and (b);
• (e) calculating a shift between images that the area measurement device has recorded of the reference surface before and after step (c) at different relative positions, with a stitching algorithm;
• (f) determining second coordinates of the measurement head, which are defined relative to the reference surface, from the shift calculated in step (e);
• and
• (g) determining third coordinates by linking the first coordinates with the second coordinates, wherein the third coordinates define points on the surface of the workpiece, which were measured by the point measurement device, relative to the reference surface.