• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1874-1875
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• 2011

본 논문에서는 스위칭 선형 시스템의 적응 LQ 준최적 제어를 위한 Q-학습법 알고리즘을 제안한다. 제안된 제어 알고리즘은 안정성이 증명된 기존 Q-학습법에 기반하며 스위칭 시스템 모델의 변수를 모르는 상황에서도 준최적 제어가 가능하다. 이 알고리즘을 기반으로 기존에 스위칭 시스템에서 고려하지 않았던 각 시스템의 불확실성 및 최적 적응 제어 문제를 해결하고 컴퓨터 모의실험을 통해 제안한 알고리즘의 성능과 결과를 검증한다.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.566-570
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• 1986

본 논문의 목적은 대규모 선형 시불변 계통에 대한 합성 제어기의 설계에 관한 새로운 방법을 제시하기 위한 것이다. 주어진 계통을 행렬 부호 함수를 이용하여 그 고유치의 크기에 따라 블럭 대각 분해하고 각부 계통에 대한 최적 제어기 및 전체계통에 대한 준최적 합성 제어기를 설계한다. 이 방법은 주어진 계통의 고유치를 미리 알 필요가 없으며 계통의 블력 분해 과정에서 Riccati 방정식및 Lyapunov 방정식의 해를 구할 필요가 없고 특이섭등 기법이나 Two time scale seperation 방법에서의 제약조건에 관계없이 광범위하게 적용되는 장점이 있다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.9
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• pp.1227-1236
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• 2001

A systematic analysis is made of suboptimal control for drag reduction. The influence of the amplitude of actuation (A) and the time scale of actuation ($\Delta$t(sub)a(sup)+) is evaluated. Two wall sensing variables are employed (∂w/∂y│(sub)w and ∂p/∂z│(sub)w) with two wall actuations (${\Phi}$$_2$and ${\Phi}$$_3$). To test the suboptimal control, direct numerical simulations of turbulent channel flow at Re(sub)$\tau$=100 are performed in a spectral domain. It is found that the effect of A and $\Delta$t(sub)a(sup)+∼1. The near-wall behaviors of flow structure are analyzed to characterize the drag reduction. The size effect of the sensor/actuator is examined.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.7
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• pp.470-477
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• 2008

The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling control system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.11
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• pp.1006-1012
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• 2007

In this paper, a suboptimal homing guidance law for the homing missiles with an impact angle constraint is presented. Unlike general LQ optimal control, the aided loop ensuring some degrees of freedom for the constraint is introduced. Then an optimal feedback loop in consideration of the aided loop is designed by using Schwartz inequality. The aided loop is synthesized with the optimal control to produce the guidance command. Furthermore, to investigate the characteristics of the guidance law we carry out the comparative studies with other guidance laws. The results of the various computer simulations show the good performance of the proposed law.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.5
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• pp.65-72
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• 1994

We resolve the suboptimal $\infty$ control problem using (J,J')-lossless coprime factorization by transforming the linear fractional transformation (LFT) into chain scattering description (CSD) in discrete-time systems. The condition transformed LFT into CSD is that the inverse matrix of $P_{21}$ of standard plant exists. But, this paper presents the method of transforming LFT into CSD for 4-block problem in case that the inverse matrix of $P_{21}$ of standard plant does not exist and parameterization of the all suboptimal $\infty$T controllers using (J,J')-lossless coprime factorization. It is shown that this method can resolve the suboptimal $\infty$ control problem solving only two Riccati equations in discrete-time systems.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.377-382
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• 2001

A suboptimal control law in turbulent pipe flow is derived and tested. Two sensing variables ${\partial}p/{\partial}{\theta}\;|_w\;and\;{\partial}{\upsilon}_{\theta}/{\partial}r\;|_w$ are applied with two actuations ${\phi}_{\theta}$ and ${\phi}_r$. To test the suboptimal control law, direct numerical simulations of turbulent pipe flow at $Re_r=150$ are performed. When the control law is applied, a $13{\sim}23%$ drag reduction is achieved. The most effective drag reduction is made at the pair of ${\partial}{\upsilon}_{\theta}/{\partial}r\;|_w$ and ${\theta}_r$. An impenetrable virtual wall concept is useful for analyzing the near-wall suction and blowing. The virtual wall concept is useful for analyzing the near-wall behavior of the controlled flow. Comparison of the present suboptimal control with that of turbulent channel flow reveals that the curvature effect is insignificant.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.3
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• pp.45-51
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• 1983

A local suboptimal controller with low sensitivity property is studied for a case of large scale systems. More specifically, necessary conditions for the suboptomal gain matrices are obtained by a parameter optimization technique, from which a design method in the form of an algorithm is suggested. To show the validity of the result and, in particular, to appreciate the effect of adding the sensitivity function, a numerical example is included.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.81-84
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• 1990

This paper presents a method of sub-optimal control for nonlinear systems via block pulse transformation. The adaptive optimal control scheme proposed by J.P. Matuszewski is introduced to minimize the performance index. The proposed method is simple and computationally advantageous. Viablity of the this method is established with simulation results for the van der Pole equation for comparision with other methods.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.12
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• pp.1273-1279
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• 1991

In this paper new adaptive approach method for sub optimal control of nonlinear systems is presented. This paper used the method proposed by J.P.Matuszewski for adaptive optimal control scheme and used block pulse transformations for solving the Riccati differential equation which is usually quite this method is estabilished with simulation results and comparisons to existing approaches.