Research into development of the defect detection system for knitted fabric produced by the circular knitting machines by image analysis

On the tubular knitted fabric produced by the circular knitting machine, the following defects in fabric sometimes appear such as vertical lines, horizontal lines, contamination, and holes, which are caused by malfunctions of the knitting machine or the poor quality of yarn used. The proposed detecting systems for these defects by other researchers have not been implemented in the industry because they appear to need excessive operating time. Therefore, development of a defect detection system using simple analysis is required. Therefore, the aim of this study is to find a simple analyzing system for vertical line defects because they often cause massive wastes of fabric. Vertical line defects could be recognized easily by analyzing brightness distribution obtained from the captured fabric image. The irregular brightness distribution obtained from our proposed method agreed with the vertical line defects; therefore, it was possible to identify the vertical line defects easily. As mentioned above, our proposed method is useful as a simple defect detection system. © 2018 by The Textile Machinery Society of Japan.