Patent ID: 8180156

Claim:
A method for machine-cutting a plate-shaped workpiece, said method comprising: contactless optical recording of data regarding position, geometry or dimensions of the workpiece using a camera, and evaluating the recorded data using image processing, wherein the recording of the data comprises a first method step of coarsely locating a workpiece edge, in which the camera is operated in a first operative mode with a first optical resolution, and a second method step for determining more exact positional data of the workpiece edge, in which the camera is operated in a second operative mode with a second optical resolution higher than said first optical resolution; and wherein the recording operation comprises: a) positioning the camera such that a recording of a first sub-area of a surface of the workpiece is obtained; b) setting first recording parameters of the camera corresponding to the first operative mode such that the recording shows a high white level with predominantly white pixels, and evaluating the recording to obtain a first group of recording and positional data; c) moving the camera in the first operative mode in a predetermined direction of movement on a predetermined movement path such that a recording of a second sub-area is obtained, said second sub-area being offset from the first sub-area and overlapping said first sub-area in an overlap region, and evaluating the recording of said second sub-area to obtain a second group of recording and positional data; d) matching the recording data of the first and the second group or evaluating the recording data only of the second sub-area as to detect whether or not a white level of the recording of the second sub-area is less than a predetermined relative or absolute limit value, and thereafter e) responsive to detecting that the white level of the recording of the second sub-area is not less than said predetermined relative or absolute limit value, further moving the camera in the first operative mode in the predetermined direction of movement and by a predetermined movement distance and iteratively repeating method steps c) and d) so as to record and evaluate the recording data of at least a further sub-area; or f) where the white level of the recording of the second sub-area is detected as being less than said predetermined relative or absolute limit value, setting second recording parameters that correspond to the second operative mode of the camera and at a higher resolution than the first recording parameters, and producing a recording of a higher resolution from the sub-area with a white level below the limit value, and evaluating the higher resolution recording with respect to the position of a workpiece edge.