PROCESS AND SEWING MACHINE FOR SEWING TOGETHER LAYERS OF FABRIC ACCORDING TO A PATTERN

摘要

PCT No. PCT/EP89/00589 Sec. 371 Date Jul. 17, 1989 Sec. 102(e) Date Jul. 17, 1989 PCT Filed May 26, 1989 PCT Pub. No. WO89/12126 PCT Pub. Date Dec. 14, 1989.Patterns of two fabric layers are each recognized by a camera and the fabric layers are aligned to make these patterns agree in the transverse and longitudinal directions. According to the invention the influence of speed-related disturbance variables and pattern-related limitations during the generation of the signal is reduced. Two-dimensional images of the two fabric layers are recorded with a matrix camera each during a pause between feeds. The degree of congurence of the fabric layers according to the pattern is determined by two-dimensional cross-correlation analysis of the image points arranged in rows and columns. Aligning correction values are calculated from this degree. The edge distance of the fabric layers is determined with a section of the matrix sensors, which is a separate section in terms of evaluation. Based on the edge distance data, the lower fabric layer is adjusted to the correct distance continuously and the upper fabric layer is adjusted as needed. If slight inaccuracies are accepted and the computation operations are limited only to the areas that are of interest, the overall computation time can be considerably reduced.