• Title, Summary, Keyword: Optimal design

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A DESIGN OF QUASI TIME-OPTIMAL FUZZY CONTROL SYSTEMS

  • Nikolai V. Rostov;Seog Chae;Oh, Young-Seok;Keum, Kyo-Un
    • Journal of Korean Institute of Intelligent Systems
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    • v.12 no.5
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    • pp.473-480
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    • 2002
  • The problems of quasi time-optimal digital control are discussed. A new design methodology of quasi time-optimal fuzzy controllers based on approximation of prototype discrete controller is suggested. Four kinds of practicable structures for fuzzy controllers are considered. Examples of computer design of quasi time-optimal fuzzy control systems are given.

Optimal Design of Fixture Layouts in Multi-Station Assembly Processes

  • Kim, Pan-Soo
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • pp.369-372
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    • 2006
  • Optimal engineering design is challenging because nonlinear objective functions need to be evaluated in a high-dimensional space. This paper presents a data-mining aided optimal design method. The method is employed in designing an optimal multi-station fixture layout. Its benefit is demonstrated by a comparison with currently available optimization methods.

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Constraint handling optimal PI control of open-loop unstable process: Analytical approach

  • Tchamna, Rodrigue;Lee, Moonyong
    • The Korean Journal of Chemical Engineering
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    • v.34 no.12
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    • pp.3067-3076
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    • 2017
  • This paper proposes the closed-form analytical design of proportional-integral (PI) controller parameters for the optimal control of an open-loop unstable first order process subject to operational constraints. The main idea of the design process is not only to minimize the control performance index, but also to cope with the constraints in the process variable, controller output, and its rate of change. To derive an analytical design formula, the constrained optimal control problem in the time domain was transformed to an unconstrained optimization in a parameter space associated with closed-loop dynamics. By taking advantage of the proposed analytical approach, a convenient shortcut algorithm was also provided for finding the optimal PI parameters quickly, based on the graphical analysis for the optimal solution of the corresponding optimization problem in the parameter space. The resulting optimal PI controller guarantees the globally optimal closed-loop response and handles the operational constraints precisely.

Process Optimal Design in Steady-State Meta Forming considering Strain-Hardening (변형률 경화를 고려한 정상상태 소성가공 공정의 공정 최적설계)

  • 황숭무
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.40-43
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    • 2000
  • A process optimal design methodology applicable to steady-state forming with a strain-hardening material is presented. in this approach the optimal design problem is formulated on the basis of a rigid-viscoplastic finite element process model and a derivative based approach is adopted as an optimization technique The process model the schemes for the evaluation of the design sensitivity considering the effect of strain-hardening and an iterative procedure for design optimization are described. the validity of the proposed approach is demonstrated through application to die shape optimal design in extrusion.

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Optimal Design of Mechanisms Using a Least Experimental Plan Method (최소 실험계획법을 이용한 기구의 최적설계)

  • 김충웅;박태원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.11
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    • pp.2883-2893
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    • 1994
  • Use of computers in design is a trend in recent years. Mechanism design also uses computers extensively and the concept of optimal mechanism design is developed in many ways. Various authors presented methods based on sensitivity analysis but in these cases, the governing equation of the mechanism has to be derived and calculations become very complicated. In this papers, a method based on the least experimental plan is presented. To make a model of a mechanism, a general purpose mechanism analysis program is used. To obtain an optimal design of a mechanism, the relationship between design variables and the objective function is represented as the nonlinear equation. Optimal design variables are found by solving this derived equation and its result is verified. An example is presented to show the effectiveness of this method.

Combined Optimal Design with Minimum Phase System (최소위상시스템을 고려한 통합최적설계)

  • 박중현
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.2
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    • pp.192-196
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    • 2004
  • A combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only the minimum weight design problem for the structure, but also the suppression problem of the effect of disturbances for the control system as the purpose of the design. A numerical example shows the validity of combined optimal design of the structure and control systems. We also consider the validity of the sensor-actuator collocation for the control system design in this paper.

Structure-Control Combined Optimal Design with S/A Collocation (센서/엑츄에이터 배치를 고려한 구조-제어 통합최적설계)

  • Park, J.H.
    • Journal of the Korea Society For Power System Engineering
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    • v.8 no.1
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    • pp.69-74
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    • 2004
  • A structure-control combined optimal design problem is discussed taking a 3-D truss structure as a design object. We use descriptor forms for a controlled object and a generalized plant because the structural parameters appear naturally in these forms. We consider not only minimum weight design problem for structure system, but also suppression problem of the effect of disturbances for control system as the purpose of the design. A numerical example shows the validity of combined optimal design of structure and control systems. We also consider the validity of sensor-actuator collocation for control system design in this paper.

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Design of Gear Dimension and Tooth Flank Form for Optimal and Robust Gear Performance (치차성능의 최적성과 강건성을 고려한 치차제원 및 치면수정의 설계)

  • 배인호;정태형
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.4
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    • pp.79-86
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    • 2004
  • Tooth errors inevitable in the manufacturing process have large effect on the strength/durability and vibration performances of gear drives. We show that the manufacturing errors affect the overall gear performances, especially vibration performance, and propose a robust optimal design method for gear dimension and its tooth flank form that guarantees reliable performances to the variation of manufacturing errors. This method begins with a search of optimal design candidates by using the previously developed gear optimal design method for the strength/durability and vibration performances. Then, the statistical analysis method is applied to find a robust design solution for the vibration performance which is generally very sensitive to the manufacturing variations.

Optimal Design and Development of Electromagnetic Linear Actuator for Mass Flow Controller

  • Chung, Myung-Jin;Gweon, Dae-Gab
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.40-47
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    • 2003
  • In this paper, we constructed the analytic model of control valve as a function of electric and geometric parameters, and analyzed the influence of the design parameters on the dynamic characteristics. For improving the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design aims to minimize the response time and maximize force efficiency. By this procedure, control valve can be designed to have fast response in motion.

Kinematic Optimal Design of a Stewart Platform based on Dexterity (조작성에 근거한 스튜엇트 플렛폼의 기구학적 최적설계)

  • 김한성;최용제
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.771-777
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    • 1996
  • In this paper, an optimal design technique for a Stewart platform has been presented considering workspace and dexterity. In the definition of a design objective function, previously suggested dexterity index was used to be maximized. In this optimal design process, the workspace can be used as design constraint when necessary. An algorithm for workspace computation has been briefly described. Finally, optimal desigm results for some example cases have been presented.

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