• Journal of Institute of Control, Robotics and Systems
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• v.6 no.9
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• pp.813-821
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• 2000

In this paper, we developed modeling of tension and speed dynamics for a two-drum winder in a three span continuous web transport system which had not been previously. Dynamic modeling of the time-varying nonlinear system was derived by considering the effect of the radii and mass moment of inertia in the unwinder and the two-drum winder through winding up the web. After linearizing it, we designed with a variable-gain a PID controller for tension control and a PI controller for speed. Simulation is carried out with the variation of radii and moment of inertia at high speed for the proposed tension control system with the two-drum winder and the variavle-gain a PID controller. Results show good performance of tension control during the speed change speed at a start-up and stop.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.4
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• pp.755-760
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• 2013

The dynamics of the winder roller of a roll-to-roll printing system for printed electronics is a time-varying system because of the variation of the winder roller radius owing to rewinding or unwinding of the web. Therefore, an adaptive control method considering the time-variant characteristics is required for precise tension control. In this study, the variable PID gain method is applied to the actual roll-to-roll system and verified by experiments for unwinder tension control. The required value of the winder roller radius for the application of the variable PID gain is estimated from the measurement of the winder tension and winder motor torque. The simulation results as well as experimental results show that the fixed PID gain control cannot stabilize the tension of the winder roller with varying winder roller radius. On the other hand, the variable PID gain method can control the tension of the winder roller regardless of the winder roller radius.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.1
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• pp.62-69
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• 2000

The strip tension as well as the line speed should be controlled tightly for the quality of products and productivity of the continuous strip processing line. In this paper, a new tension control algorithm with tension observer is proposed using observed tension as regulator feedback. The tension observer is based on the torque balance of a roller stand including the acceleration torque. Using this estimated tension, new tension controller can be constructed with faster dynamic response in case of line speed acceleration or deceleration. The proposed scheme needs no additional hardware because the inputs of observer, current and speed, are already being monitored by the motor drive system. Through the simulations and experiments with laboratory set up, performances fo conventional schemes and proposed one are compared. The results show the effectiveness of the proposed tension controller.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.917-920
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• 1995

A mathematical model describing the relationship between longitudinal tension and tangential velocity of web/roller in a multi-span web transport system has been developed. An experiment was carried out for typical conditions to validate the mathematical model for tension behavior in a multispan system. A two-span prototype prototype web transport system with winder and unwinder was manufactured for the experiment. By comparing simulation and experimental results, the mathematical model for tension and velocity in a multi-span web transport system is confirmed to be valid for typical conditions. Tension transfer phenomenon was also confirmed though the simulation as well as experimentation.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.11a
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• pp.74-80
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• 2002

A mathematical tension model for a moving web in a multi-span web handling system was derived and validated by using a simulator which includes unwinder, driven roller, winder, load cells, controllers, etc. A tension controller was designed to compensate tension disturbances generated by velocity changes of the unwinder and driven roller. From experimental results it was proved that the tension model properly expressed the tension behavior of a moving web for specific conditions. The distributed tension controller designed by using the pole-placement technique compensated the tension disturbances transfered from upsteram tension variation. Interactions between web spans including "tension transfer phenomenon" were clearly confirmed through the study. A mathematical model of lateral motion of a moving web was verified also by using the same experimental apparatus which includes displacement type guidance systems. And a feedforward control strategy was designed for more accurate control of the lateral motion of a moving web, which utilize a measured signal of the lateral displacement of web in a previous span and a more correctly identified mathematical model to estimate the disturbance of lateral motion from the previous span. This approach was turned out to be effective in improving the performance of the guidance system for more wide range disturbances.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.65-72
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• 2000

This paper presents the study of the tension control in a web transfer system. In this study the sliding mode controller is applied to a time-varying nonlinear mathematical model. The model was derived to consider the effects of changing the roll radius in tension variation during winding and unwinding. The uncertainty in modeling may be due to unmodelled dynamics, on variations in system model. Designed sliding mode controller made the system error always staying in the suggested surface from the beginning. Through this, system is maintained to be robust against a disturbance and uncertainty. To verify the designed controller has a good performance, various inputs such as desired velocity, step input, and trapezoidal input are applied. When the sliding mode controller was used, the system(the tension control) performance was improved comparing to the PID controller. The robustness of the controller with respect to an estimation error was verified through simulations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.327-331
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• 1997

This paper presents the non-linear modeling and design of a robust sliding mode controller for film transfer systems. The tension of a film is sensitive to the speed difference between a winder and an unwinder. The change of the roll-radius as well as the moment of inertia result in the film transfer system begin variable and non-linear. In designing the robust controller. Two major aims are considered. The first aim is hat the web transferring speed tracks at any given reference speed; the second one is that the tension of the film tracks at any given reference tension. To verify the control algorithm, a Simulink model was built and compared with a conventional PID controller. In a computer simulation study, the suggested robust sliding mode controller shows better performance than the PID controller a various control inputs.