Research Article Defect Detection Techniques for Airbag Production Sewing Stages Raluca Brad, 1 Lavinia Barac, 2 and Remus Brad 2 1 Industrial Machinery and Equipment Department, Lucian Blaga University of Sibiu, B-dul Victoriei 10, 550024 Sibiu, Romania 2 Computer Science and Electrical Engineering Department, Lucian Blaga University of Sibiu, B-dul Victoriei 10, 550024 Sibiu, Romania Correspondence should be addressed to Raluca Brad; raluca.brad@ulbsibiu.ro Received 25 November 2013; Accepted 17 January 2014; Published 25 February 2014 Academic Editor: Nabil Ibrahim Copyright © 2014 Raluca Brad et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Airbags are subjected to strict quality control in order to ensure passengers safety. Te quality of fabric and sewing thread infuences the fnal product and therefore, sewing defects must be early and accurately detected, in order to remove the item from production. Airbag seams assembly can take various forms, using linear and circle primitives, with threads of diferent colors and length densities, creating lockstitch or double threads chainstitch. Te paper presents a framework for the automatic detection of defects occurring during the airbag sewing stage. Types of defects as skipped stitch, missed stitch, or superimposed seam for lockstitch and two threads chainstitch are detected and marked. Using image processing methods, the proposed framework follows the seams path and determines if a color pattern of the considered stitches is valid. 1. Introduction Te term of product quality refers primarily to the product ability to fulfll the purpose for which it was designed, while performing a quality control assumes a regular check of quality products variables. Terefore, the quality features which will be subsequently tested need to be defned. Te textiles products are assessed according to several criteria, depending on their destination. For instance, technical tex- tiles have to meet close specifcations of weight, fexibility, and strength, while in the case of apparel, quality characteristics as design, color, and comfort are important. Te airbag is a safety device designed for modern vehicles, required to infate quickly in the case of a collision, preventing the passengers from crashing onto the cars’ interior [1]. Te concept of airbag was introduced in the late 1960s, but it was increasingly employed afer 1990, due to market requirements and imposed legislation. Generally, the air cushion is woven from nylon flament yarns suitable due to the high strength- to-weight proportion, favorable elongation, adequate thermal properties, and relatively low cost of production. In average, to produce a driver’s airbag, about 1.42 meters of material is needed. Other mandatory features for airbag are high tensile strength, seam stability, air permeability, and ability to be folded and stored in dark for years, without sufering any damage [2]. To fulfll the designed functionality, it is neces- sary that all these properties are valid. Terefore, the quality control of airbag production is extremely important, because a minor defect can infuence the cushions performance. Quality control is very strict for airbags, especially in the areas of propulsion, static, and dynamic infation and of fabrics and seams quality. In the case of fabric quality, critical parameters refer to: tensile strength and elongation of weaving yarns, tensile strength of material, fabric density and weight, air permeabil- ity (both for static and dynamic air) and slip resistance of the seam [3]. Tus, a rigorous testing and quality control starting from the yarns used in weaving to the fnal sewing operation is absolutely necessary. In the past decades, seams quality control was visu- ally performed by human experts pursuing two goals: a continuous control to prevent the sale of poor quality products and setting the optimal parameters for sewing machines. One of the frst automated techniques for seam control was reported in [4], employing a laser to scan the Hindawi Publishing Corporation Journal of Textiles Volume 2014, Article ID 738504, 7 pages http://dx.doi.org/10.1155/2014/738504