• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.78-86
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• 2003

Multivariable control system exist widely in many types of systems such as chemical processes, biomedical processes, and the main steam temperature control system of the thermal power plant. Up to the present time, Pill Controllers have been used to operate these systems. However, it is very difficult to achieve an optimal PID gain with no experience, because of the interaction between loops and gain of the Pill controller has to be manually tuned by trial and error. This paper suggests a tuning method of the Pill Controller for the multivariable power plant using an immune algorithm, through computer simulation. Tuning results by immune algorithms based neural network are compared with the results of genetic algorithm.

• 대한전기학회논문지:전력기술부문A
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• 제48권8호
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• pp.980-986
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• 1999

In this paper, the optimal controller which decouples a coupled multivariable system and minimizes a quadratic performance index is proposed. Design of the controller is based on the two-degree-of-freedom standard model. The class of all stabilizing and decoupling controllers is parametrized first and the $H^{2}$optimal controller is obtained by using this parametrized form. An illustrative example for a $2{\times}2$ plant is given.

• 대한기계학회논문집A
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• 제21권3호
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• pp.502-510
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• 1997

A disturbance rejection controller using eccentricity filtering and LQ control techniques is proposed to alleviate the effecto of major roll eccentricity in multivariable cold-rolling processes. Fundamental problems in multivariable cold-rolling processes such as process time delay inherent in exit thickness measurement and non-stationary characteristics of roll eccentricity signals can be overcome by the proposed control method. The filtered instantaneous estimate of roll eccentricity may be exploited to improve instantaneous estimate of the exit thickness variation based on roll force and roll gap measurements, and a feedforward compensator is augmented as a reference for a gaugemeter thickness estimator. LQ feedback controller is combined with eccentricity filter for the attenuation of the exit thickness variation due to the entry thickness variation. The simulation results show that the roll eccentricity disturbance is significantly eliminated and other disturbances also are attenuated.

• 제어로봇시스템학회논문지
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• 제5권6호
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• pp.744-752
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• 1999

In this paper, we studied the response characteristics of $\alpha$, $\beta$ separated type, combined type, PI typed, and feedforward type in 2DOF-PID controller through the simulation and the experiments designed with the multivariable flow control system. The parameters $\alpha$ and $\beta$ give an affect to characteristics of controller in separated type but $\gamma$ does not give an affect to the characteristics of 2-DOF PID. The more $\beta$ increases, the more overshoot decreases and especially, in case of PI type represent clearly. The $\alpha$, $\beta$ separated type has a very small overshoot and its magnitudes in 2-DOF PID onctroller increases in order of $\alpha$, $\beta$ combined type, PI type, feedforward type, conventional type. The response characteristics of simulation are similar to that of experiments but the experimental characteristics in the multivariable flow control system has the delayed response. The time delay of response in experiments depends on 2-DOF parameter $\alpha$, $\beta$, $\gamma$ and the overshoot increase as the $\alpha$, $\beta$, $\gamma$ increase. So, we can have a satisfactory response by tuning D gain.

• 한국산업융합학회 논문집
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• 제9권3호
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• pp.173-178
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• 2006

For the design of multivariable fuzzy control systems decomposition of control rules is a efficent inference method since it alleviates the complexity of the problem. In some systems, however, inference error of the Gupta's decomposition method is inevitable because of its approximate nature. In this paper we define indices of applicability which decides whether the decomposition method can be applied to a multivariable fuzzy system or not.

• 한국해양공학회지
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• 제9권2호
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• pp.30-40
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• 1995

In this paper, it is proposed a robust control scheme for real time control of a robot manipulator with parameter uncertainties. The focus of this paper is a new approach of multivariable control schemes for an assembly robot manipulator to achieve the accurate trajectory tracking by joint angles. The proposed control scheme consists of a multivariable feedforward controller and feedback controller. In this control scheme, the feedback controller consists of proportional-derivative type and is designed by the pole placement method. The feedforward controller uses the inverse of the linealized model of robot manipulator dynamics. This feedback controller ensures that each joint enables to track any reference trajectory. The proposed robot controller scheme has a computational efficiency.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.160-163
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• 1996

This paper deals with MCMBPC(Multivariable Constrained Model Based Predictive Controller) for nonlinear boiler system with noise and disturbance. MCMBPC is designed by linear state space model obtained from some operating point of nonlinear boiler system and Kalman filter is used to estimate the state with noise and disturbance. The solution of optimization of the cost function constrained on input and/or output variables is achieved using quadratic programming, viz. singular value decomposition (SVD). The controller designed is shown to have excellent tracking performance via simulation applied to nonlinear dynamic drum boiler turbine model for 16OMW unit.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.924-930
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• 1989

This paper presents the design of simple robust controller for a class of uncertain multivariable systems. We introduce switching dynamics instead of switching logics unlike variable structure control scheme. Also, we can construct the continuous control law from this switching dynamics and consequently remove the chattering motion. The dynamic equations of the range-space of a switching surface matrix C and uniform ultimate boundedness in the presence of parameter uncertainties are described mathematically.

• 전자공학회논문지S
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• 제34S권7호
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• pp.66-77
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• 1997

This paper presents an automatic tuning method for parameters of a multivaiable self-tuning velocity-type PID controller which adapts to changes in the system parameters with time delays and noises. The velocity-type PID control structure is determined in the process of minimizing the variance of the auxiliarly output, and self-tuning effect is achieved through the recursive least square algorithm at the parameter estimation stage and also through the Robbins-Monro algorithm at the stage of optiminzing the design parameters of the controller. The proposed PID type multivariable self-tuning method is simple andeffective compared with other esisting multivariable self-tuning methods. Computer simulation has shown that the proposed algorithm is beter than the trial-and-error method in the tracking performance.

• 전자공학회논문지SC
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• 제38권5호
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• pp.14-22
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• 2001

본 논문에서는 비선형 다변수 시스템의 신경망 식별과 신경망제어기 설계방법을 제안한다. 신경망제어기는 독립된 여러 개의 선형제어기와 하나의 신경회로망으로 구서오디며, 신경회로망은 간접 제어방식에 의해 학습된다. 제안한 제어방식을 IBM 컴퓨터 상에 구현하고 물체를 공유한 막대부하 시스템의 속도제어에 적용한다. 신경회로망의 식별능력과 제안한 제어기의 성능을 실험결과로서 살펴보고 기존의 선형제어기와 비교함으로서 제안한 제어기의 우수함을 확인한다.