Fuzzy control for manufacturing quality based on variable precision rough set

Traditional approaches to quality control have several limitations as modern manufacturing processes become more complex and sweeping. A composite model of rough set and fuzzy set is constructed to learn the uncertain, incomplete, inconsistent and fuzzy behavior of the manufacturing processes function for quality control. Since the original rough set is usually contaminated by noise natural to the manufacturing processes, an extensive rough set is suggested by means of variable precision, which is noise tolerant. The integrated method of variable precision rough set and fuzzy set can produce a powerful model of quality control due to their complementary natures. Based on the model, the controller is able to extract control rules easily from processing data and set new operating specifications. At last, the effectiveness of the method is verified by the experiments.