Moonyong Lee

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A new method for PID controller tuning based on process models for cascaded control systems is proposed in this paper. The method consists of first finding the ideal controller that gives the desired closed loop response and then finding the PID approximation of the ideal controller by Maclaurin series. This method can be applied to any open loop stable(More)
Proportional, integral, and deriuatiue (PID) parameters are obtained for general process models by approximating the feedback form of an IMC controller with a Maclaurin series in the Laplace uariable. These PID parameters yield closed-loop responses that are closer to the desired responses than those obtained by PID controllers tuned by other methods. The(More)
Keywords: Multi-loop PI/PID controller tuning Effective open-loop transfer function (EOTF) Model reduction Internal model control (IMC) Dynamic relative gain array a b s t r a c t The interactions between input/output variables are a common phenomenon and the main obstacle encountered in the design of multi-loop controllers for interacting multivariable(More)
Induction of glucose-regulated proteins (GRPs) is a ubiquitous intracellular response to stresses such as hypoxia, glucose starvation and acidosis. The induction of GRPs offers some protection against these stresses in vitro, but the specific role of GRPs in vivo remains unclear. Hibernating bats present a good in vivo model to address this question. The(More)
Ethylene plant is one of the largest plants and the thermal cracking furnace is a key unit in the ethylene plant. Since ethylene is the basic material in the chemical industry and the market situation of not only the feed and the product, but also the utility is rapidly changing, the optimal operation of the plant is important. CRACKER, a PC based software(More)
The design of the PID controller cascaded with first order filter has been proposed for the second order unstable time delay processes. The design algorithm is based on the IMC criterion which has single tuning parameter to adjust the performance and robustness of the controller. The setpoint filter is used to diminish the overshoot in servo response. The(More)
The proposed IMC-PID tuning method is extension of the recently published setpoint overshoot method (2010). It is one step procedure to obtain the PI/PID setting which gives the better performance and robustness. The method requires one closed-loop step setpoint response experiment using a proportional only controller with gain K<sub>c0</sub>. Based on(More)
The present study suggested a modified disturbance estimator in a recently published two-degree-of-freedom control scheme for open-loop unstable process with time delay. A simple PID controller cascaded with lead lag filter replaces the high order disturbance estimator for enhanced performance. A new analytical method, which has only one tuning parameter,(More)