scholarly journals Spatially Dependent Transfer Functions for Web Lateral Dynamics in Roll-to-Roll Manufacturing

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Edison O. Cobos Torres ◽  
Prabhakar R. Pagilla
Keyword(s):  
Transfer Functions ◽  
Lateral Position ◽  
Lateral Transfer ◽  
Web Handling ◽  
Lateral Dynamics ◽  
Roll To Roll ◽  
The Laplace Transform ◽  
Lateral Behavior ◽  
Lateral Positioning ◽  
The Web

Spatially dependent transfer functions for web span lateral dynamics which provide web lateral position and slope as outputs at any location in the web span are derived in this paper. The proposed approach overcomes one of the key limitations of the existing methods which provide web lateral position only on the rollers. The approach relies on taking the Laplace transform with respect to the temporal variable of both the web span lateral governing equation and the boundary conditions on the rollers, and solving the resulting equations. A general web span lateral transfer function, which is an explicit function of the spatial position along the span, is obtained first followed by its application to common guide configurations. The approach also significantly simplifies the consideration of shear (relevant to short spans), in addition to bending, which has been found to be difficult to handle in past studies. We first develop spatially dependent lateral transfer functions by considering only bending which is relevant to most web handling situations, and then add shear to the formulation and develop spatially dependent lateral transfer functions that include both bending and shear. Results from model simulations and pertinent discussions are provided. The spatially dependent transfer functions derived in this paper are a significant improvement over existing lateral transfer functions and provide mechanisms to analyze web lateral behavior within spans, study propagation of lateral disturbances, and aid in the development of closed-loop lateral control systems in emerging applications that require precise lateral positioning of the web.

The behavior of cambered belts transiting cylindrical rollers

2021 ◽  
pp. 095440892110644
Author(s):  
Jinxin Shi ◽  
Sheng Pan ◽  
Ron E. Markum ◽  
James K. Good
Keyword(s):  
Steady State ◽  
Boundary Conditions ◽  
Closed Form Solution ◽  
Form Solution ◽  
Length Variation ◽  
Lateral Deformation ◽  
Roll To Roll ◽  
Manufactured Products ◽  
Lateral Behavior ◽  
The Web

The lateral deformations of webs in roll-to-roll process machines can affect the quality of the manufactured products. Webs with simple nonuniform length variation across their width (camber) will steer toward the long side, leading to the steady state lateral deformation and hence registration. Most previous studies have focused on a cambered web in a free span between two rollers. These studies assume some displacement and slope boundary conditions are known and seek the remaining conditions that would dictate the steady state lateral deformation of the web. This article focuses on the lateral behavior of a cambered web belt transiting between two aligned rollers as the simplest case of multiple span cambered web. Dynamic simulation has been conducted to better understand the response of a cambered web under tension that has been witnessed in tests. There are no boundary conditions enforced and no steady state deformation of the cambered webs. Thus there is no closed-form solution to the lateral movement of a cambered web transits over multiple rollers. This explained why the previous research focused more on the experimental exploration without few theoretical validations. The web travels toward the long side continually from one span to the next until a web guide attempts to return the web to an acceptable lateral location in the process machine.

Boundary Conditions That Govern the Lateral Behavior of Flexible Webs in Roll to Roll Process Machines

2013 ◽  
Vol 9 (1) ◽  
Author(s):  
B. Fu ◽  
A. Reddy ◽  
S. Vaijapurkar ◽  
R. Markum ◽  
J. K. Good
Keyword(s):  
Laser Doppler Velocimetry ◽  
Previous Analysis ◽  
State Behavior ◽  
Friction Forces ◽  
Explicit Finite Element ◽  
Roll To Roll ◽  
Process Machinery ◽  
Frictional Forces ◽  
Lateral Behavior ◽  
The Web

Thin web materials are commonly transported through machinery where a process adds value to the web. The flexible web is supported intermittently by contact with rollers. The friction forces associated with this contact are largely responsible for determining the lateral mechanics and dynamics of the thin web transiting rollers in roll-to-roll process machinery. The investigation focuses on cases where slippage between the rollers and web has become substantial and has resulted in a complex lateral behavior of the web. Two methods are presented for investigating the frictional forces and the resulting lateral behavior. The first method employs explicit finite element (FE) dynamic analysis to study the lateral mechanics of the web after steady state behavior has been achieved. This method allows the direct study of the frictional forces. The second method employs Laser Doppler Velocimetry in a novel experimental noncontact technique to examine internal loads within the web, which were influenced by the frictional forces. Both methods are shown to provide results, which agree with one another and with previous analysis. The analyses are used to form a new friction boundary condition between a web and roller that will benefit other analysis methods.

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.

Lateral Dynamics of a Real Moving Web

1971 ◽  
Vol 93 (3) ◽  
pp. 180-186 ◽  
Author(s):  
J. J. Shelton ◽  
K. N. Reid
Keyword(s):  
Control Systems ◽  
Transfer Functions ◽  
Companion Paper ◽  
Operating Conditions ◽  
Lateral Dynamics ◽  
Order Analysis ◽  
First Order ◽  
Mechanics Analysis ◽  
Systematic Derivation ◽  
The Web

A second-order method is presented which uses the results of static mechanics analysis for the systematic derivation of ordinary differential equations describing the lateral dynamic behavior of massless, moving webs. The theory relates the lateral dynamics of a web at a downstream roller to the longitudinal web velocity, the angle between the web and the roller, the induced web curvature, and the roller dynamics. Transfer functions are derived for several fundamental elements which are found in practical web guide control systems. A comparison of these results with those of a first-order analysis presented in a companion paper, is presented to illustrate the inadequacy of the latter for certain frequency ranges and operating conditions. Experimental verification of two transfer functions is presented.

A simple way for producing holographic filters suitable for image improvement

1978 ◽  
Vol 36 (1) ◽  
pp. 226-227
Author(s):  
K.-H. Herrmann ◽  
E. Reuber ◽  
P. Schiske
Keyword(s):  
Transfer Functions ◽  
Diffraction Order ◽  
Lateral Position ◽  
Simple Method ◽  
Spatial Frequencies ◽  
Resolution Electron ◽  
Wiener Filters ◽  
Image Improvement ◽  
Optical Reconstruction ◽  
Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

Register control of roll-to-roll gravure-offset printing equipment considering time difference between measurement and actuation

2012 ◽  
Vol 226 (11) ◽  
pp. 2726-2738 ◽  
Author(s):  
Chung Hwan Kim ◽  
Ha-Il You ◽  
Seung-Hyun Lee
Keyword(s):  
Measurement System ◽  
Position Control ◽  
Printed Electronics ◽  
Control Method ◽  
Axial Direction ◽  
Time Difference ◽  
Offset Printing ◽  
Drying Time ◽  
Roll To Roll ◽  
The Web

The manufacture of printed electronics by roll-to-roll printing machine requires more accurate register performance than conventional media printing technology. Moreover, high drying temperature and long drying time to sinter the inks can induce the substantial changes in the length of the substrate and consequently register errors. Among the roll-to-roll printing methods, the gravure one, despite its relatively fast productivity and fine-line printing capacity, has difficulty in achieving the required register specifications for printed electronics because of the dependence of the register control on web dynamics. This study proposes a roll-to-roll gravure-offset printing equipment, including the register measurement system designed to enhance register performance and the related register control method for the application of printed electronics. Each cylinder constituting the printing unit is driven independently by an individual servomotor. Moreover, the printing patterns of the plate cylinder can move in the axial direction by position control, as well as in the web transport direction by a phase shift of the plate cylinder, without affecting the dynamics of the web. The time difference between the measurement and the actual control action is considered and modeled. The register measurement system, including selections of sensors and marks is also proposed to consider the effect of the time difference. The simulation results and the experiments of the register control are shown to verify the effect of the time difference on the control performances. It is found that a proper estimation of time difference should be obtained in order to guarantee more accurate and stable control performances.

Effect of Lateral Positioning on Upper Airway Size and Morphology in Sedated Children

2005 ◽  
Vol 103 (3) ◽  
pp. 484-488 ◽  
Author(s):  
Ronald S. Litman ◽  
Nicole Wake ◽  
Lai-Ming Lisa Chan ◽  
Joseph M. McDonough ◽  
Sanghun Sin ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Supine Position ◽  
Upper Airway ◽  
Lateral Position ◽  
Magnetic Resonance Images ◽  
Magnetic Resonance Imaging Examination ◽  
Vocal Cords ◽  
Cross Sectional ◽  
Spontaneously Breathing ◽  
Lateral Positioning

Background Lateral positioning decreases upper airway obstruction in paralyzed, anesthetized adults and in individuals with sleep apnea during sleep. The authors hypothesized that lateral positioning increases upper airway cross-sectional area and total upper airway volume when compared with the supine position in sedated, spontaneously breathing children. Methods Children aged 2-12 yr requiring magnetic resonance imaging examination of the head or neck region using deep sedation with propofol were studied. Exclusion criteria included any type of anatomical or neurologic entity that could influence upper airway shape or size. T1 axial scans of the upper airway were obtained in the supine and lateral positions, with the head and neck axes maintained neutral. Using software based on fuzzy connectedness segmentation (3D-VIEWNIX; Medical Imaging Processing Group, University of Pennsylvania, Philadelphia, PA), the magnetic resonance images were processed and segmented to render a three-dimensional reconstruction of the upper airway. Total airway volumes and cross-sectional areas were computed between the nasal vomer and the vocal cords. Two-way paired t tests were used to compare airway sizes between supine and lateral positions. Results Sixteen of 17 children analyzed had increases in upper airway total volume. The total airway volume (mean +/- SD) was 6.0 +/- 2.9 ml in the supine position and 8.7 +/- 2.5 ml in the lateral position (P < 0.001). All noncartilaginous areas of the upper airway increased in area in the lateral compared with the supine position. The region between the tip of the epiglottis and vocal cords demonstrated the greatest relative percent change. Conclusions The upper airway of a sedated, spontaneously breathing child widens in the lateral position. The region between the tip of the epiglottis and the vocal cords demonstrates the greatest relative percent increase in size.

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.

Estimation of uncertainties in fault lateral positioning on 3D PSDM seismic image: an example from the North West Shelf

2016 ◽  
Vol 56 (2) ◽  
pp. 556
Author(s):  
Sergey Birdus ◽  
Vincent Ganivet ◽  
Alexey Artemov ◽  
Ray Teakle ◽  
Paul Phythian
Keyword(s):  
Practical Interest ◽  
Velocity Model ◽  
Lateral Position ◽  
Second Step ◽  
North West ◽  
The North ◽  
Seismic Image ◽  
Estimation Of Uncertainties ◽  
The Impact ◽  
Lateral Positioning

This extended abstract presents a two-step sequence to estimate uncertainties in lateral positioning of fault planes on 3D PSDM (pre-stack depth migration) seismic images. This analysis can be applied to any localised detail on a seismic image but, in the majority of geological settings, it is most important for the faults. The first step provides an approximate evaluation of what causes the uncertainties, how the uncertainties are distributed in a 3D space, and what to expect within target zones. The authors assume that every complex detail within a 3D PSDM velocity model causes some uncertainties to the seismic image below. Thus, the uncertainties at a target level depend on the complexity of the overburden and the seismic acquisition parameters. At this step a qualitative 3D volume of lateral fault position uncertainties is created. In the second step the authors focus on a single fault of practical interest. Based on the results of the first step, the authors modify the existing 3D PSDM anisotropic velocity model by introducing additional anomalies that cause maximal changes to the lateral position of the fault on seismic image. Then the authors iteratively re-migrate a small sub-volume around the fault and check the PSDM images and residual moveout. The objective is to find out how far the velocity variations can move the image of the fault and still satisfy available seismic data. The second step gives more reliable quantitative estimations of the impact of velocity on fault positioning. A real multi-azimuth 3D seismic dataset from the North West Shelf is used to illustrate this sequence.

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