• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.871-878
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• 2013

Roll-to-roll (R2R) hot embossing systems have been developed and are widely used in various industrial domains. These systems press and heat flexible films between a press roll and a back-up roll, as said films pass through the two rolls. In previous studies, a heating roll was used for heating. However, in this study, a hybrid roll for R2R hot embossing is conceptualized and developed. This R2R system can be used for generating fine patterns on large and continuous films. The hybrid roll of our system can cool and heat the films simultaneously, thus affording greater flexibility in process design. Thermal and structural analyses were performed for developing the hybrid roll. In addition, a hybrid roll was designed based on analytical results. Experiments were conducted for measuring the performance of the developed hybrid roll.

• Laser Solutions
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• v.16 no.4
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• pp.17-23
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• 2013

The research for the development of roll-to-roll printing process is actively underway on behalf of the existing semiconductor process. The roll-to-roll printing system can make the electronic devices to low-cost mass production. This study is performed for developing the manufacturing technology of the printing roll used in the printing process of electronic devices. The indirect laser engraving technology is used to create printable roll and the printable roll is made out of the chrome coated roll after coating copper and polymer on the surface of steel roll, ablating the polymer on the surface of roll and etching the roll. The 3 dimensional laser scanner and roll rotating systems are constructed and the system control program is developed. We have used the fiber laser of 100 W grade, the 3 dimensional laser scanner and the 3 axes moving stage system with a rotating axis. We have found the optimal conditions by performing the laser patterning experiments and can make the minimum line width of $24{\mu}m$ by using the developed 3 dimensional laser scanner system.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.12
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• pp.1011-1016
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• 2015

In a roll-to-roll continuous system, winding is one of the most important processes since it determines the quality of the final manufactured products such as flexible film and printed electronic devices. Since an adequate winding tension can reduce the incidence of the defects that are derived from the inner stress of the wound roll such as starring and telescoping, it is necessary to determine the optimal taper-tension profile. In this study, an algorithm for the setting of an optimal taper-tension profile in consideration of the residual stress in the wound roll is suggested; furthermore, the algorithm was adjusted for the determination of an optimal taper-tension profile regarding the winding process of $10{\mu}m$ polypropylene (PP) film. As a result of the algorithm-generated, optimal taper-tension profile, the residual stress and radial stress in a PP wound roll were decreased to 27.37 % and 40.05 % (mean value), respectively.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.180.2-180
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• 2001

In the hot rolling process, the RF AGC (Roll Force Auto Gauge Control) is used to control the roll gap to reduce the variation of rolling force caused by the roll eccentricity and the variation of material thickness. However the effect of the roll eccentricity cannot be distinguished. To eliminate the effect of the roll eccentricity, the roll eccentricity estimation is needed to supplement some drawbacks of RF AGC. In this paper, an ALE(Adaptive Line Enhancer) that extracts the rolling force variation due to the roll eccentricity is suggested. We also provide an algorithm that enhances the convergence time of roll eccentricity estimation. The performance improvement of the Suggested algorithm is shown via simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.701-705
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• 2014

This article presents a comparison among several yaw and roll motion controllers for vehicle rollover prevention. In the previous research, yaw and roll motion controllers can be independently designed for rollover prevention. Following this idea, several yaw and roll motion controllers are designed and compared in terms of rollover prevention. For the yaw motion control, PID, LQR, SMC (Sliding Mode Control) and TDC (Time-Delay Control) are adopted. For the roll motion control, LQR, LQ SOF (Static Output Feedback) control, PID, and SMC are adopted. To compare the performance of each controller, simulation is performed on a vehicle simulation package, CarSim$^{(R)}$. From simulation, TDC and LQ SOF are the best for yaw and roll motion control, respectively.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.792-797
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• 2009

This paper presents the evaluation of PID and fuzzy control logic for the lateral position control of a moving web in roll-to-roll (R2R) printed electronics. In addition, we report the implementation of computer simulation software that enables us to develop the control logic in a graphic user interface and to test the controller performance in 3D dynamic environment. A mathematical model of the web dynamics is described first to explain the lateral motion of a moving web. Based on the model, PID and fuzzy controllers are designed, and embedded in the simulation software. Under the simulation conditions for fabricating RFID antenna by R2R printing, the results indicate that the fuzzy controller shows a better performance and can be more suitable for R2R multi-layer printed electronics.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.7
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• pp.713-718
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• 2006

Supersonic jet fighter aircraft have several different weapon loading configuration to support air-to-air combat and air-to-ground delivery of weapon modes. Especially, asymmetric loading configurations could result in decreased handling qualities for the pilot maneuvering of the aircraft. The design of the T-50 lateral-directional roll axis control laws change from beta-betadot feedback structure to simple roll rate feedback structure and gains such as F-16 in order to improve roll-off phenomena during pitch maneuver in asymmetric loading configuration. Consequently, it is found that the improved control law decreases the roll-off phenomenon in lateral axes during pitch maneuver, but initial roll response is very fast and wing pitching moment is increased. In this paper, we propose the lateral control law blending between beta-betadot and simple roll rate feedback system in order to decreases the roll-off phenomenon in lateral axes during pitch maneuver without degrading of roll performance.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.3
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• pp.167-172
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• 2017

This study proposes a method for identifying correlations between tension and drop height for sessile droplets in a roll-to-roll processing system. The effect of tension and drop height on the contact angle of a sessile droplet is presented. Design of experiment (DOE) methodology and statistical analysis are used to define a correlation between the process parameters. The contact angle is decreased while increasing tension and drop height. The influence of the tension is less significant on the contact angle compared with the effect of the drop height. However, tension should be considered as a major parameter because it is not easy to fix with roll eccentricity and compensating speed of the driven roll. The results of this study show that the effect of tension on the contact angle of a sessile droplet is more important than drop height because the drop height is fixed when the process systems are determined.

• Ocean Systems Engineering
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• v.5 no.2
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• pp.55-76
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• 2015

Of all the six degrees of freedom, the roll motion of a ship is the most poorly understood and displays complicated phenomena. Due to the low potential wave damping at the natural frequency, the effective analysis of ship roll dynamics comes down to the accurate estimation of the viscous roll damping. This paper provides overview of the importance of roll damping and an extensive literature review of the various viscous roll damping prediction methods applied by researchers over the years. The paper also discusses in detail the current state of the art estimation of viscous roll damping for ship shaped structures. A computer code is developed based on this method and its results are compared with experimental data to demonstrate the accuracy of the method. While some of the key references describing this method are not available in English, some others have been found to contain typographic errors. The objective of this paper is to provide a comprehensive summary of the state of the art method in one place for future reference.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.325-328
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• 1997

In this paper the modeling and control of a twin roll strip caster is investigated. Mathematical models for the strip casting process are obtained by analyzing five critical areas such that the molten steel level in the pool, solidification process, roll separating force and torque, roll dynamics including hydraulic actuators, and roll drive system. A two-level control strategy is proposed. At lower level, three local subsystems are independently feedback-controlled by suitable local controllers which perform well to the behaviors of each subsystem. They are a variable structure control of the molten steel level in the pool, an adaptive predictive control of the roll gap which is directly related to the strip thickness, and an $H^{\infty}$ control of the roll drive system. At higher level, all reference signals to the lower level subsystems are generated by an optimal controller in the perspective of regulating the strip thickness and roll separating force. Simulations are provided..