1. A method for controlling robots for welding three-dimensional workpieces, having the following steps: positioning and tack-welding profiles onto a plate in order to form the workpiece to be welded, imaging the workpiece by means of a three-dimensional image detection system in the form of three-dimensional pixels, determining the geometrical data of the plate and of the profiles from the three-dimensional pixels as point cloud by segmentation of the latter, the segmentation including separating the points of the workpiece from the background, separating points of the plate from points of the profiles and separating points of different profiles from each other, by establishment of profile courses and examination of the segmented point cloud with respect to properties of the different profiles, including assigning cutouts and end cut edges, determining the weld seam data from the geometrical data taking into account the profile placement lines and the contact lines of profiles, and assigning the weld seam data to parameterisable specifications for the welding plan to stored predefined movement patterns of the robot and also to commands for controlling and regulating the welding process.