| 摘要 |
The system to monitor the stitched seam at a sewing machine, during stitching, has an electronic camera (2) with its lens (2a) aligned at the stitching to show the stitches in a point or fleck display. The camera (2) is linked to an image processor (8) to convert the individual stitch signals into a form where they can be stored electronically to be accessed to show the actual image signals and to determine the actual stitch intervals. A comparator (10) compares the actual and nominal stitch intervals stored in memory (12). An evaluation unit (14) automatically triggers a fault sequence in the event of a deviation of the actual stitch interval from the nominal value. The nominal stitch interval defines a tolerance range, with a lower and an upper threshold. The evaluation unit (14), in matching the actual and nominal stitch intervals, is connected to an optical and/or acoustic working display. The fault sequence controls an optical and/or acoustic fault alarm, and stops the stitching action. The fault sequence also applies an automatic correction to the stitching action, to shift the actual stitch interval into the nominal range. The image processor (8) initially determines that the camera signals refer to the stitching zone, by comparing the signals with stored data. The image processor (8) sets the center point of each fleck image for a stitch, to compute the mean gap between neighboring stitches. The actual stitch interval is determined continuously during sewing, and stored for a continuous statistical evaluation. The camera (2) is a video camera, pref. combined with a control monitor (18).
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