Browsing by Author "George Hodge, Committee Member"

Now showing 1 - 3 of 3

The Application of MEMS Accelerometers for Accurately Finding Warp Yarn Breaks in Textile Machinery
(2003-07-06) Slusser, Tim; Edward Grant, Committee Chair; George Hodge, Committee Member; Mark White, Committee Member
The textile industry, particularly in the weaving areas, needs sensors to monitor for faults and to aid the automation of warp yarn repair. As MEMS (MicroElectroMechanical Systems) technology advances, sensors and actuators get smaller. MEMS sensors are very powerful and are highly accurate. These sensors are inexpensive and are readily available. Currently, in the textile machinery, drop wires are used to monitor the tension of the warp yarns in the weaving process. These drop wires are abrasive to the warp yarns and can lead to more warp yarn breaks. Therefore, it would be beneficial to develop a system that does not contact the warp yarn in any way, such that extra warp yarns are not broken because of the sensor. This research has led to the development of a sensor system that has no contact with the warp yarn. The main purpose was to show proof of concept for applying a MEMS sensor to the textile machinery, specifically the Jacquard Loom, in order to develop a sensor system having no contact with the warp yarns. A MEMS Accelerometer, available from Analog Devices, was used to monitor the motion of the heddle, whose acceleration properties change based on the presence of the warp yarn. Matlab was used to interpret the data and analyze for broken warp yarns (using recorded data) based on the change in acceleration. Once a warp yarn is determined to have been broken, Matlab would notify the user.
Computer Modeling of Fiber Motion in High-Speed Airflow
(2003-07-16) Cai, Yiyun; George Hodge, Committee Member; Douglas Reeves, Committee Member; Yiping Qiu, Committee Member; William Oxenham, Committee Chair
High-speed airflow is widely used in many processes in today's textile industry. Even though the interactions between fibers and airflows have attracted many researchers' interest, there have been few published studies that focus on the computer modeling of fiber motion in airflow fields. The present research was aimed at developing a model that can effectively simulate the interactions between fibers and airflows, thus providing clearer understanding of the behavior of textile fibers in certain processing machines. A three-dimensional model of an aerodynamic component of a textile machine was developed. A commercial computation fluid dynamics (CFD) software package was used to compute the airflow field of this model and the results were analyzed to study the airflow field's characteristics. Resultant data were used as input for the fiber movement model by using a one-way coupling method. The mathematical model of fiber movement was constructed by integrating the governing equations with a model that describes the fiber configurations. A numerical method was developed to solve these equations and visualization programs were established to illustrate and animate the simulated fiber movements. The results obtained were studied and compared under different initial and boundary conditions. Fiber bending and twisting properties were integrated into the computer model. Their influences on the fiber movement were simulated and analyzed. The present research successfully demonstrates the effectiveness of computer modeling for studying the fiber motion in high-speed airflow. It can provide better understanding of fiber behavior in airflow fields and its potential and prospect in the research of textile processes, in which airflow plays an important role, are very promising.
A Novel Method for Dynamic Yarn Tension Measurement and Control in Direct Cabling Process
(2006-03-29) Shankam Narayana, Vivek Prasad; Abdelfattah Seyam, Committee Co-Chair; William Oxenham, Committee Co-Chair; George Hodge, Committee Member; Edward Grant, Committee Co-Chair
Yarn tension control is an important parameter for quality and efficiency in textile processes. It has a significant influence on productivity in various processes such as winding, twisting and cabling. There have been several articles based on theoretical models, which discuss the effect of various factors on yarn tension variation in direct cabling, but very few have addressed the possibility of measuring and controlling it practically while the yarn is being twisted. Quality control system manufacturers like TEMCO (Textile Machinery Components) and BTSR (Best Technologies Studies and Research) have come up with smart tension scanning systems that perform online tension monitoring in various textile machines. However, these systems cannot be installed on the direct cabling machine due to their size and cost. The fact that the supply yarn package is housed inside the rotating yarn balloon restrains any wired tension sensor from performing online measurement. As such, there is an immediate need for using a wireless sensing device to perform online yarn tension measurement and execute a control mechanism that will control yarn tension adaptively. The objective of this research is to demonstrate the possibility of applying MEMS (MicroElectroMechanical Systems) technology with radio frequency (RF) transmission to effectively carry out dynamic online measurement for the control of yarn tension. A novel technique to achieve online control using the measured real-time data has been implemented. A device that ensures uniform tension in the yarn has been designed and developed. Ways of measuring twist in the cabled yarn using optical micrometers and digital imaging systems have also been explored, because variation in tension manifests variation in twist. Using the twist values obtained from these sensors, the individual tensions in the component yarns can be adjusted, resulting in the formation of a uniform cabled yarn with equal lengths of both component yarns.