SEAM FAULT DETECTION THOUGH SIGNATURE ANALYSIS

摘要

The aim of this research project was to investigate whether there was any significant change in both the thread consumption and the seam strength, by altering various factors on the sewing machine at the same time. These were the thread tension, hook timing, needle position and the number of fabric plies. Through a course of 2~4 factorial experiments, employing a previously developed On-line Sewing Thread Utilisation Monitoring System, the various affects, caused by the changing factors, were monitored and analysed with a high degree of accuracy without interfering with the natural stitch formation process. It was found from the experiments that by advancing the hook timing and needle position, thread consumption was reduced while the seam strength was increased, while not increasing peak dynamic tension of the needle thread. The needle thread tension and the needle thread consumption signatures were shown to be an indicator of changes made to the stitch forming elements during the experimental investigations. These correlated with changes in the seam strength. These two signatures could be used to identify seam faults due to misalignment of the stitch forming elements occurring during the normal cause of sewing.