• Title/Summary/Keyword: nonlinear & complex systems

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Neural Model Predictive Control for Nonlinear Chemical Processes

  • Song, Jeong-Jun;Park, Sunwon
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.899-902
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    • 1993
  • A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming combined with neural identification network is used to generate the optimum control law for complex continuous chemical reactor systems that have inherent nonlinear dynamics. The neural model predictive controller (MNPC) shows good performances and robustness. To whom all correspondence should be addressed.

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Control of complex distillation configuration (복합 증류계의 제어)

  • 한명완;박선원
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.742-748
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    • 1993
  • The dynamics and control of two complex column configurations (sidestream column with stripper; prcfractionater/sidestream column configuration), which are multivariable interacting and nonlinear, have been studied. A new control scheme developed by Hanand Park(1993) to deal with the nonlinear and multivariable nature of distillation processes has been applied to these complex distillation configurations. The control scheme incorporates a nonlinear wave model into a generic model control framework. An observer based on the nonlinear wave model is used to determine the profile positions of distillation column sections. The control scheme enables tight control of the profile position of each column section that leads to fast stabilization of product compositions.

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A Study on the Deadbeat Response Attribute of Nonlinear Systems (비선형시스템의 데드비트응답 특성 연구)

  • Song, Ja-Youn
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.1993-1995
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    • 2001
  • The subject of nonlinear control is an important area of automatic control. The behavior of nonlinear systems is much more complex. If the operating range of a control system is small, and if the involved nonlinearities are smooth, then the control system may be resonably approximated by a set of linear differential equations. This paper presents the deadbeat response attribute of some nonlinear systems, e.g., magnetic levitation, pendulum, van der pol oscillator etc.. The studied results through the computer simulation are shown a promising attribute of deadbeat response that the outputs of the systems are reached relatively fast the steady state.

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Forecasting High-Level Ozone Concentration with Fuzzy Clustering (퍼지 클러스터링을 이용한 고농도오존예측)

  • 김재용;김성신;왕보현
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.05a
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    • pp.191-194
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    • 2001
  • The ozone forecasting systems have many problems because the mechanism of the ozone concentration is highly complex, nonlinear, and nonstationary. Also, the results of prediction are not a good performance so far, especially in the high-level ozone concentration. This paper describes the modeling method of the ozone prediction system using neuro-fuzzy approaches and fuzzy clustering. The dynamic polynomial neural network (DPNN) based upon a typical algorithm of GMDH (group method of data handling) is a useful method for data analysis, identification of nonlinear complex system, and prediction of a dynamical system.

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Identification of nonlinear dynamical systems based on self-organized distributed networks (자율분산 신경망을 이용한 비선형 동적 시스템 식별)

  • 최종수;김형석;김성중;권오신;김종만
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.4
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    • pp.574-581
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    • 1996
  • The neural network approach has been shown to be a general scheme for nonlinear dynamical system identification. Unfortunately the error surface of a Multilayer Neural Networks(MNN) that widely used is often highly complex. This is a disadvantage and potential traps may exist in the identification procedure. The objective of this paper is to identify a nonlinear dynamical systems based on Self-Organized Distributed Networks (SODN). The learning with the SODN is fast and precise. Such properties are caused from the local learning mechanism. Each local network learns only data in a subregion. This paper also discusses neural network as identifier of nonlinear dynamical systems. The structure of nonlinear system identification employs series-parallel model. The identification procedure is based on a discrete-time formulation. Through extensive simulation, SODN is shown to be effective for identification of nonlinear dynamical systems. (author). 13 refs., 7 figs., 2 tabs.

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Design of nonlinear system controller based on radial basis function network (Radial Basis 함수 회로망을 이용한 비선형 시스템 제어기의 설계에 관한 연구)

  • 박경훈;이양우;차득근
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1165-1168
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    • 1996
  • The neural network approach has been shown to be a general scheme for nonlinear dynamical system identification. Unfortunately the error surface of a Multilayer Neural Network(MNN) that widely used is often highly complex. This is a disadvantage and potential traps may exist in the identification procedure. The objective of this paper is to identify a nonlinear dynamical systems based on Radial Basis Function Networks(RBFN). The learning with RBFN is fast and precise. This paper discusses RBFN as identification procedure is based on a nonlinear dynamical systems. and A design method of model follow control system based on RBFN controller is developed. As a result of applying this method to inverted pendulum, the simulation has shown that RBFN can be used as identification and control of nonlinear dynamical systems effectively.

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Design Robust Fuzzy Model-Based Controller for Uncertain Nonlinear Systems (불확실 비선형 시스템을 위한 강인한 퍼지 모델 기반 제어기)

  • Joo, Young-Hoon;Chang, Wook;Park, Jin-Bae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.8
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    • pp.407-414
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    • 2000
  • This paper addresses the analysis and design of fuzzy control systems for a class of complex uncertain single-input single-output nonlinear systems. The proposed method represents the nonlinear system using a Takagi-Cugeno fuzzy model and construct a global fuzzy logic controller by blending all local state feedback controllers with a sliding mode controller. Unlike the commonly used parallel distributed compensation technique, we can design a global stable fuzzy controller without finding a common Lyapunov function for all local control systems, and can obtain good tracking performance by using sliding mode control theory. Furthermore, stability analysis is carried out not for the fuzzy model but for the real nonlinear system with uncertainties. Duffing forced oscillation sysmte is used as an example to show the effectiveness and feasibility of the proposed method.

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Adaptive Fuzzy Output Feedback Control based on Observer for Nonlinear Heating, Ventilating and Air Conditioning System

  • Baek, Jae-Ho;Hwang, Eun-Ju;Kim, Eun-Tai;Park, Mi-gnon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.2
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    • pp.76-82
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    • 2009
  • A Heating, Ventilating and Air Conditioning (HVAC) system is a nonlinear multi-input multi-output (MIMO) system. This system is very difficult to control the temperature and the humidity ratio of a thermal space because of complex nonlinear characteristics. This paper proposes an adaptive fuzzy output feedback control based on observer for the nonlinear HVAC system. The nonlinear HVAC system is linearized through dynamic extension. State observers are designed for estimating state variables of the HVAC system. Fuzzy systems are employed to approximate uncertain nonlinear functions of the HVAC system with unavailable state variables. The obtained controller compares with an adaptive feedback controller. Simulation is given to demonstrate the effectiveness of our proposed adaptive fuzzy method.

Forecasting High-Level Ozone Concentration with Fuzzy Clustering (퍼지 클러스터링 이용한 고농도오존예측)

  • 김재용;김성신;왕보현
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.4
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    • pp.336-339
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    • 2001
  • The ozone forecasting systems have many problems because the mechanism of the ozone concentration is highly complex, nonlinear, and nonstationary. Especially, the performance of the prediction results in the high-level ozone concentration are not good. This paper describes the modeling method of the ozone prediction system using neuro-fuzzy approaches and fuzzy clustering methods. The dynamic polynomial neural network (DPNN) based upon a typical algorithm of GMDH (group method of data handling) is a useful method for data analysis, the identification of nonlinear complex systems, and prediction of dynamical systems.

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Multivariable control of robot manipulators using fuzzy logic (퍼지논리를 이용한 로봇 매니퓰레이터의 다변수제어)

  • 이현철;한상완;홍석교
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.490-493
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    • 1996
  • This paper presents a control scheme for the motion of a 2 DOF robot manipulator. Robot manipulators are multivariable nonlinear systems. Fuzzy logic is avaliable human-like control without complex mathematical operation and is suitable to nonlinear system control. In this paper, Implementation of fuzzy logic control of robotic manipulators shows. Algorithm has been performed with simulation packages MATRIXx and SystemBuild.

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