• 제목/요약/키워드: Process control systems

검색결과 3,447건 처리시간 0.028초

Adaptive Fuzzy Neural Control of Unknown Nonlinear Systems Based on Rapid Learning Algorithm

  • Kim, Hye-Ryeong;Kim, Jae-Hun;Kim, Euntai;Park, Mignon
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2003년도 추계 학술대회 학술발표 논문집
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    • pp.95-98
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    • 2003
  • In this paper, an adaptive fuzzy neural control of unknown nonlinear systems based on the rapid learning algorithm is proposed for optimal parameterization. We combine the advantages of fuzzy control and neural network techniques to develop an adaptive fuzzy control system for updating nonlinear parameters of controller. The Fuzzy Neural Network(FNN), which is constructed by an equivalent four-layer connectionist network, is able to learn to control a process by updating the membership functions. The free parameters of the AFN controller are adjusted on-line according to the control law and adaptive law for the purpose of controlling the plant track a given trajectory and it's initial values are off-line preprocessing, In order to improve the convergence of the learning process, we propose a rapid learning algorithm which combines the error back-propagation algorithm with Aitken's $\delta$$\^$2/ algorithm. The heart of this approach ls to reduce the computational burden during the FNN learning process and to improve convergence speed. The simulation results for nonlinear plant demonstrate the control effectiveness of the proposed system for optimal parameterization.

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SE 전산지원도구를 이용한 형상관리 방안 연구 (Study of Configuration Management Using Se Tool)

  • 박종선
    • 시스템엔지니어링학술지
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    • 제7권1호
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    • pp.53-56
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    • 2011
  • Configuration management plays a key role in systems engineering process for any project from earlier stage of development. It consists of five major activities, ie., configuration management planing, configuration identification, configuration control, configuration status accounting and configuration verification and audit, and is essential to control system design, development and operation throughout entire life cycle of the system development. And it is directly associated with other part of systems engineering management process, ie., technical data management which provides traceability of important decisions and changes during development. In this paper, we describe how to apply CASE(Computer-aided Systems Engineering) tool-Cradle for the configuration management to achieve effectiveness of Technical Management process.

모델예측제어기반 상용 Package PCTP를 이용한 화학공정의 제어 고도화 연구 (Study of Advanced Control for Chemical Process Using the Commercial Package PCTP Based on Model Predictive Control Algorithm)

  • 박준호;박호철;이문용
    • 제어로봇시스템학회논문지
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    • 제13권11호
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    • pp.1128-1136
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    • 2007
  • This paper presents an application study of a model predictive control based commercial package PCTP to real chemical processes. The first case study concerns a product purity control of a splitter process which distillates styrene from undesired component ethyl-benzene produced from ethyl-benzene dehydrogenation reaction. The second case study is about a temperature control of ethyl-benzene dehydrogenation reactor and an excess oxygen control of the fired heater. Optimum control structure for MPC application is developed for each case study. The application results show a significant improvement in control performance and stability.

벡터 인버터를 이용한 연속공정 제어 시스템 개발 (Development of continuous Process Control System Using Vector Inverter)

  • 변성훈;홍찬욱;김영민;김정하;권봉현
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2005년도 전력전자학술대회 논문집
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    • pp.48-50
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    • 2005
  • This paper presents the design and development of web control algorithm of continuous process control system using vector inverter. The Diameter of web is calculated, tension is controlled by PID control and the speed reference of motor is calculated at current diameter. The performance of web control in this paper is verified by experiment.

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MPC Based Feedforward Trajectory for Pulling Speed Tracking Control in the Commercial Czochralski Crystallization Process

  • Lee Kihong;Lee Dongki;Park Jinguk;Lee Moonyong
    • International Journal of Control, Automation, and Systems
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    • 제3권2호
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    • pp.252-257
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    • 2005
  • In this work, we propose a simple but efficient method to design a target temperature trajectory for pulling speed tracking control of the crystal grower in the Czochralski crystallization process. In the suggested method, the model predictive control strategy is used to incorporate the complex dynamic effect of the heater temperature on the pulling speed into the temperature trajectory design quantitatively. The feedforward trajectories designed by the proposed method were implemented on 200 mm and 300 mm silicon crystal growers in the commercial Czochralski process. The application results have demonstrated its excellent and consistent tracking performance of pulling speed along whole bulk crystal growth.

Approximate Dynamic Programming Strategies and Their Applicability for Process Control: A Review and Future Directions

  • Lee, Jong-Min;Lee, Jay H.
    • International Journal of Control, Automation, and Systems
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    • 제2권3호
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    • pp.263-278
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    • 2004
  • This paper reviews dynamic programming (DP), surveys approximate solution methods for it, and considers their applicability to process control problems. Reinforcement Learning (RL) and Neuro-Dynamic Programming (NDP), which can be viewed as approximate DP techniques, are already established techniques for solving difficult multi-stage decision problems in the fields of operations research, computer science, and robotics. Owing to the significant disparity of problem formulations and objective, however, the algorithms and techniques available from these fields are not directly applicable to process control problems, and reformulations based on accurate understanding of these techniques are needed. We categorize the currently available approximate solution techniques fur dynamic programming and identify those most suitable for process control problems. Several open issues are also identified and discussed.

Radial basis function 회로망을 이용한 새로운 신경망 선형화 제어구조 (A new neural linearizing control scheme using radial basis function network)

  • 김석준;이민호;박선원;이수영;박철훈
    • 제어로봇시스템학회논문지
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    • 제3권5호
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    • pp.526-531
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    • 1997
  • To control nonlinear chemical processes, a new neural linearizing control scheme is proposed. This is a hybrid of a radial basis function(RBF) network and a linear controller, thus the control action applied to the process is the sum of both control actions. Firstly, to train the RBF newtork a linear reference model is determined by analyzing the past operating data of the process. Then, the training of the RBF newtork is iteratively performed to minimize the difference between outputs of the process and the linear reference model. As a result, the apparent dynamics of the process added by the RBF newtork becomes similar to that of the linear reference model. After training, the original nonlinear control problem changes to a linear one, and the closed-loop control performance is improved by using the optimum tuning parameters of the linear controller for the linear dynamics. The proposed control scheme performs control and training simultaneously, and shows a good control performance for nonlinear chemical processes.

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연속 공정 자동화를 위한 라인 제어기에서의 실시간 작업 스케쥴링에 관한 연구 (Design of Real Time Task Scheduling for Line Controller of Continuous Manufacturing Process Automation)

  • 이준수;조영조;임미섭;박정민;최익;임준홍;김광배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 A
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    • pp.365-368
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    • 1992
  • This paper presents an approach to the design of real time task scheduling for a line controller of continuous manufacturing process automation. The line controller has multiprocessor-based architecture with shared memory and is operated by firmware. This firmware contains menu-driven software supporting real-time database management and fuction-block control language. The multitasking line control processor performs the following three functions: 1) interprets the function block control language by virtue of shared memory in the database; 2) invokes an interupt service routine as required by external hardware; 3) detects errors and notifies the user. We propose real time task scheduling method.

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Applications of neural networks in manufacturing process monitoring and control

  • Cho, Hyung-Suck
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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    • pp.11-21
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    • 1992
  • Modern manufacturing process requires machine intelligence to meet the demands for high technology products as well as intelligence-based operating skills to lessen human worker's intervene. To meet this trend there has been wide spread interest in applying artificial neural network(ANN) to the areas of manufacturing process monitoring and control. This paper addresses application problems in such processes as welding, assembly, hydroforming process and inspection of solder joints.

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Design of Generalized Minimum Variance Controllers for Nonlinear Systems

  • Grimble Michael J.
    • International Journal of Control, Automation, and Systems
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    • 제4권3호
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    • pp.281-292
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    • 2006
  • The design and implementation of Generalized Minimum Variance control laws for nonlinear multivariable systems that can include severe nonlinearities is considered. The quadratic cost index minimised involves dynamically weighted error and nonlinear control signal costing terms. The aim here is to show the controller obtained is simple to design and implement. The features of the control law are explored. The controller obtained includes an internal model of the process and in one form is a nonlinear version of the Smith Predictor.