A Nonlinear Tension Control Scheme for Web Transport Through Heating Processes

2015 ◽  
Author(s):  
Youwei Lu ◽  
Prabhakar R. Pagilla
Keyword(s):  
Heat Transfer ◽  
Thermal Effects ◽  
Tension Control ◽  
Web Based ◽  
Transfer Processes ◽  
Roll To Roll ◽  
Flexible Material ◽  
Control Scheme ◽  
The Web ◽  
Web Tension

In this paper we develop a model-based nonlinear tension control scheme for transport of flexible materials (webs) through heating processes. Heat transfer processes are widely employed in Roll-to-Roll (R2R) process machines that are used to perform processing operations on a moving web on rollers. Heat transfer processes induce thermal expansion/contraction of the flexible material during transport. Because web strain and elastic modulus are functions of temperature distribution in the web, web tension resulting from elastic strain is affected by heating/cooling of the web. Based on a web tension governing equation that includes both elastic and thermal effects, a nonlinear tension control scheme is developed for control of tension in each tension zone of an R2R system. The control scheme is implemented on an R2R experimental platform containing two heat transfer rollers, one for heating the web and one for subsequently cooling the web prior to winding of the web. Experimental results are presented and discussed.

Modeling of Temperature Distribution in Moving Webs in Roll-to-Roll Manufacturing

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Youwei Lu ◽  
Prabhakar R. Pagilla
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Thermal Strain ◽  
Heat Transfer Model ◽  
Operating Conditions ◽  
Transfer Model ◽  
Roll To Roll ◽  
Flexible Material ◽  
Process Line ◽  
The Web

A heat transfer model that can predict the temperature distribution in moving flexible composite materials (webs) for various heating/cooling conditions is developed in this paper. Heat transfer processes are widely employed in roll-to-roll (R2R) machines that are used to perform processing operations, such as printing, coating, embossing, and lamination, on a moving flexible material. The goal is to efficiently transport the webs over heating/cooling rollers and ovens within such processes. One of the key controlled variables in R2R transport is web tension. When webs are heated or cooled during transport, the temperature distribution in the web causes changes in the mechanical and physical material properties and induces thermal strain. Tension behavior is affected by these changes and thermal strain. To determine thermal strain and material property changes, one requires the distribution of temperature in moving webs. A multilayer heat transfer model for composite webs is developed in this paper. Based on this model, temperature distribution in the moving web is obtained for the web transported on a heat transfer roller and in a web span between two adjacent rollers. Boundary conditions that reflect many types of heating/cooling of webs are considered and discussed. Thermal contact resistance between the moving web and heat transfer roller surfaces is considered in the derivation of the heat transfer model. Model simulations are conducted for a section of a production R2R coating and fusion process line, and temperature data from these simulations are compared with measured data obtained at key locations within the process line. In addition to determining thermal strain in moving webs, the model is valuable in the design of heating/cooling sources required to obtain a certain desired temperature at a specific location within the process line. Further, the model can be used in determining temperature dependent parameters and the selection of operating conditions such as web speed.

Modeling the Effects of Heat Transfer Processes on Material Strain and Tension in Roll to Roll Manufacturing

2013 ◽  
Author(s):  
Youwei Lu ◽  
Prabhakar R. Pagilla
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Distribution Model ◽  
Tension Zone ◽  
Governing Equations ◽  
Flexible Materials ◽  
Transfer Processes ◽  
Roll To Roll ◽  
Average Modulus ◽  
The Web

This paper develops governing equations for material strain and tension based on a temperature distribution model when the flexible materials (often called webs) are transported on rollers through heat transfer processes within roll-to-roll (R2R) processing machines. Heat transfer processes are employed widely in R2R systems that contain process operations such as printing, coating, lamination, etc., which require heating/cooling of the moving web material. The heat transfer processes introduce the thermal expansion/contraction of the material and changes in the elastic modulus. Thus, the temperature distribution in the moving material affects the strain distribution in the material. Because of change in strain as well as modulus as a function of temperature, tension in the material resulting from elastic strain is also affected by heating/cooling of the web. To obtain the temperature distribution, two basic heat transfer modes are considered: web wrapped on a heat transfer roller and the web span between two consecutive rollers. The governing equations for strain is then obtained using the law of conservation of mass considering the temperature effects. Subsequently, a governing equation for web tension is obtained by assuming the web is elastic with the modulus varying with temperature; an average modulus is considered for defining the constitutive relation between web strain and tension. Since it is difficult to obtain measurement of tension using load cell rollers within heat transfer processes, a tension observer is designed. To evaluate the developed governing equations, numerical simulations for a single tension zone consisting of a heat transfer roller, a web span, and a driven roller are conducted. Results from these numerical model simulations are presented and discussed.

scholarly journals Kalman-Filter-Based Tension Control Design for Industrial Roll-to-Roll System

Algorithms ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 86 ◽  
Author(s):  
Hyeongjin Hwang ◽  
Jehwon Lee ◽  
Sangjune Eum ◽  
Kanghyun Nam
Keyword(s):  
Kalman Filter ◽  
Control Method ◽  
Tracking Error ◽  
Tension Control ◽  
External Disturbances ◽  
Roll To Roll ◽  
Control Scheme ◽  
Roll System ◽  
The Web

This paper presents a robust and precise tension control method for a roll-to-roll (R2R) system. In R2R processing, robust and precise tension control is very important because improper web tension control leads to deterioration in the quality of web material. However, tension control is not easy because the R2R system has a model variation in which the inertia of the web in roll form is changed and external disturbances caused by web slip and crumpled web. Therefore, a disturbance observer (DOB) was proposed to achieve robustness against model variations and external disturbances. DOB is a robust control method widely used in various fields because of its simple structure and excellent performance. Moreover, the web passes through various process steps to achieve the finished product in the R2R process. Particularly, it is important to track the tension when magnitude of the tension varies during process. Feedforward (FF) controller was applied to minimize the tracking error in the transient section where tension changes. Moreover, the signal processing of a sensor using the Kalman filter (KF) in the R2R system greatly improved control performance. Finally, the effectiveness of the proposed control scheme is discussed using experimental results.

Advanced Motion Control Design for Longitudinal Web Dynamics in Roll-to-Roll Systems: Velocity or Position Control?

2013 ◽  
Author(s):  
Y. Martz ◽  
J. Frechard ◽  
D. Knittel
Keyword(s):  
Control Strategy ◽  
Position Control ◽  
Tension Control ◽  
Web Handling ◽  
Reference Tracking ◽  
External Loop ◽  
Roll To Roll ◽  
Processing Line ◽  
The Web ◽  
Web Tension

Roll-to-Roll systems handling web material such as papers, polymers, textiles or metals are very common in the industry. One of the main objectives in web handling plant is to reach an expected web speed while maintaining the web tension within an acceptable range around the tension reference in the entire processing line. In the recent years, several works have focused on the topic of web tension control using H∞ approaches. In the traditional way, each motor driven roller is controlled in speed and the web tension control is ensured by an external loop. This paper proposes to compare, for the first time, the traditional control strategy with a control strategy including position control rather than speed control. In fact, position control is commonly used in printing industry. The comparison will be ensured in frequency and time domain and take into account the reference tracking performances and the robustness to web elasticity variations.

Advanced Optimization of Industrial Large-Scale Roll-to-Roll Systems Under Parametric Uncertainties

2012 ◽  
Author(s):  
J. Frechard ◽  
D. Knittel
Keyword(s):  
Young’S Modulus ◽  
Large Scale ◽  
Young's Modulus ◽  
Robust Design Optimization ◽  
Parametric Uncertainties ◽  
Optimization Approach ◽  
Roll To Roll ◽  
Polymer Metal ◽  
The Web ◽  
Web Tension

In industrial plants some parameters can not be evaluated properly or they are varying with time. These parametric uncertainties has to be taken into account during the design process of industrial systems. In this work, the developped optimization approach is applied on an industrial roll-to-roll sytem. Such systems are commonly used to handle materials as polymer, metal, paper and textile. The key challenge is to move the web at the expected speed while maintaining the web tension in an acceptable range around its reference. Moreover, the Young’s modulus of the web is difficult to evaluate and it is varying with time due to temperature and moisture variations. This paper deals with the web tension controller synthesis on a large-scale roll-to-roll system with uncertain Young’s modulus. To synthesize web tension controllers, an H∞ approach is applied and adapted to the system with parametric uncertainties using multi-objective robust design optimization.

Bahnzugkraftregelung in der Batteriezellfertigung*/Web tension control in battery cell production

2018 ◽  
Vol 108 (07-08) ◽  
pp. 519-524
Author(s):  
H. Weinmann ◽  
F. Lang ◽  
J. Hofmann ◽  
J. Fleischer
Keyword(s):  
Dimensional Accuracy ◽  
Tension Control ◽  
Selection Function ◽  
Battery Cell ◽  
Cell Production ◽  
Material Parameters ◽  
Single Sheet ◽  
The Web ◽  
Web Tension

Viele Maschinen- und Materialparameter sind für die Qualität eines Elektroden-Einzelblattes verantwortlich. Relevant für Vereinzelung und Stapelbildung ist etwa die Bahnzugkraft, mit der die Elektrodenbahn während des Stanzvorgangs beaufschlagt wird. Diese wurde in der Versuchsanlage des wbk Institut für Produktionstechnik regelbar ausgeführt, um Zusammenhänge bei der Einzelblattstapelbildung zu untersuchen. Dieser Artikel stellt Auswahl und Funktion sowie die Integration der Lösung in die Versuchsanlage und die Auswirkung verschiedener Bahnzugkräfte auf die Maßhaltigkeit der gestanzten Einzelblätter vor.   The quality of an electrode single-sheet is affected by a multitude of machine and material parameters, such as the web tension force for separating and stacking applied to the electrode web during die cutting. As an adjustable force it was analyzed in a demonstrator at the wbk Institute of Production Science to identify interdependencies during single-sheet-stacking. This article presents the selection, function and integration of the solution into a demonstrator and how different web tension forces affect the dimensional accuracy of die-cut sheets.

scholarly journals Roll-to-roll infrared and hot-air sintering of gravure-printed Ag layer based on in situ tension measuring and analysis

2016 ◽  
Vol 4 (38) ◽  
pp. 8884-8888 ◽  
Author(s):  
Janghoon Park ◽  
Hyi Jae Kang ◽  
Hyogeun Gil ◽  
Kee-Hyun Shin ◽  
Hyunkyoo Kang
Keyword(s):  
Hot Air ◽  
Roll To Roll ◽  
The Web ◽  
Web Tension

The sintering energy was quantified and evaluated based on theoretical and experimental calculations. Moreover, the effect of the sintering energy on the web tension was simultaneously considered.

System for Automatic Web Guiding for Roll-to-Roll Machine Working in a Start-Stop Mode

2014 ◽  
Vol 223 ◽  
pp. 374-382
Author(s):  
Mirosław Neska ◽  
Andrzej Majcher
Keyword(s):  
Material Processing ◽  
Control System ◽  
Processing Machine ◽  
Processing Machinery ◽  
Roll To Roll ◽  
Transport Velocity ◽  
The Web ◽  
Selection Of ◽  
Web Tension ◽  
Hardware Structure

Web guiding used in roll-to-roll material processing machinery is connected with a number of issues including the maintenance of the web tension, the precision of the lateral web displacement, the accuracy of transport positioning of the web, and the selection of web transport velocity. The article presents the precision of the lateral web displacement issue during the start-stop work mode of the web transport. A model of a system for automatic web guiding is shown. The requirements of the lateral web guiding for transporting material over rollers in a processing machine working in a start-stop mode are presented. The control system is discussed, particularly its hardware structure and behaviour. The obtained functionality of the control system enables its application in roll-to-roll material processing machines, working either in the start-stop mode or continuously.

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