• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.3
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• pp.46-54
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• 1984

A new controller tuning method for solving problems that cannot be applicable to the processes with large time delay by Yuwana-Seborg method is presented. The new method is based on a single experimental test, a step change in the controller set point. Simulation results show that the new method can be not only well applicable to systems including large delay processes but also is superior to Ziegler-Nichols method or Cohen-Coon method in many respects despite unanticipated load disturbances that may occur during the experimental test.

• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.5
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• pp.647-652
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• 1986

The controller tuning methods proposed by Yuwana-Seborg and Suh utilizes Pade first order approximation for the delay terms in the closed loop transfer function. In this paper, the use of a Pade second-order approximation method is investigated. The simulation results show that the new method is superior to pervious approaches such as Ziegler-Nichols and Cohen-Coon methods.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.27-36
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• 1993

It is well know that the tuning method of Yuwana-Seborg (1982) can not be even applied to the relatively small delay system due to the phase errors from the Pad approximation suh (1984, 85, 86). Jutan and Rodriguez(1984), lee(1989), Chen(1989), Lee and Edgar(1990), etc have been tried to improve it. In this stydy, such recent results and their problems are investigated. A new tuning method by "a frequency scale transformation". which is based on a previous result of Suh(1984). is proposed. It can reduce the magnitude of the phase error significantly.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.106-108
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• 2005

The calculation of parameters of a process model is modified to find that better sliding mode controller for a process with time delay. A design method by Camacho has such problems as chattering, overshoot due to the Pade approximation errors for the time delay term of the first order model. In this paper, a new design technique for a sliding mode controller is proposed by introducing the modified Pade approximation considering the weight factor. The modified method is expected to provide a more accurate model with better control settings.