Computer vision for textured yarn interlace (nip) measurements at high speeds

This paper deals specifically with interlace measurements of intermingled. false-twist textured yarns. A system has been built which is capable of ana lysing yarns at slow-speed/high-resolution. and also at high-speed/low-reso lution, An outline description of the system is given here, along with desc riptions of techniques used in the hardware and software which improve the system performance. To monitor interlace, a signal processing algorithm is developed and explained which enables reliable interlace detection, and is effective against diametric noise. Several tests are carried out, which pro ve the ability of the system to match the results from careful manual inspe ction of the yarn. The final test is to run the yarn at a high speed, and t o compare the results with the slow-speed analysis. The results show that a t high speeds, the system is reliable. (C) 2001 Elsevier Science Ltd. All r ights reserved.