Study On Visual-driven Ring Spinning Of High-count Yarn With Direct Yarn-end Feeding Device

In the production of fine yarn using ring spinning,automatic piecing of broken yarn has always been a challenge in the textile industry due to the small cross-sectional area of high-count yarn and the uncertain position of randomly attached broken yarn on the surface of the bobbin.Therefore,studying the technology of automatic piecing of high-count yarn has important engineering significance and practical needs.In this paper,a vision-driven automatic piecing method for high-count yarn in ring spinning is studied to achieve high efficiency and success rate.For the key operations in the piecing process,namely the loosening and stripping of yarn,machine vision technology is studied to detect broken yarns and ensure precise frictional loosening of yarns for subsequent stripping operations.Numerical simulation technology is used to design key parameters of the stripping mechanism to ensure stable airflow for successful stripping of high-count yarn.The main research work is as follows:Based on the introduction of the characteristics of broken yarns in ring spinning of high-count yarns,this paper analyzes the difficulties in the automatic piecing of broken high-count yarns and the reasons for the low success rate of existing direct piecing methods(currently,the success rate of piecing on the winding machine is only60%).To address this problem,a vision-driven direct piecing solution for high-count yarns in ring spinning is proposed,and a corresponding device is designed to achieve automatic piecing of broken high-count yarns.Aiming at the visual detection of high-count yarn breakage in the process of precise friction loosening,the small target detection method of weak feature breakage based on Swin-YOLOv5 is studied,and a weak feature extraction method of yarn breakage that integrates the local context information of broken yarn is proposed to realize yarn breakage.Weak features of high-count yarn with variable shape and noise interference in the image are extracted;the fast regression method of small target anchor frame of broken yarn is designed and improved CIo U＿Loss,and the fast regression of small target anchor frame is realized to improve the model detection speed.The experimental results show that the proposed detection method has a detection accuracy of 92.89% at a detection speed of 28 FPS,which is 13.39% higher than the YOLOv5 detection method.Practical loosening operation application requirements for small targets.Based on the stable air flow stripping,a key parameter design method for the stripping mechanism based on flow field analysis is studied.According to the stripping method of positive pressure blowing and reverse rotation rewinding of the cylinder,a corresponding geometric model of the stripping mechanism is established.Through the motion capture of the flow-solid boundary at the interface of the composite sliding mesh,the simulation of the jet flow passing around the rotating cylinder is realized.A method of comparative analysis of flow field simulation is proposed to reveal the influence of key parameters of the stripping mechanism on the flow field around the cylinder.The stripping mechanism with an air blowing mechanism diameter of 3mm and a tilt angle of 80° with the horizontal plane,and a step motor rewinding speed of 1250 rpm is determined to achieve stable air flow stripping.Based on the above theories,and with the background of the actual spinning-up application of high-count yarn breakage,a vision-driven high-count yarn spinning-up prototype was built to verify the rationality and performance of the method proposed in this paper.The experimental results show that under the same broken bobbin state,the determined key parameters of the yarn stripping mechanism are better than other comparison parameters,and the prototype can stably realize yarn breakage with a success rate of 84%,much higher than the winder spin-up link.,which provides an effective solution to the automatic spinning problem of high-count yarn breakage in the spinning production process.The research results of this paper provide theoretical reference and technical support for the development of ring spinning high-count yarn breakage direct spinning technology,which has important engineering value.