• 제목/요약/키워드: Optimal performance design

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민간도해석에 의한 자동차 현가장치의 성능개선에 관한 연구 (Performance improvement of a vehicle suspension by sensitivity analysis)

  • 송척기;박호;오재응;염성하
    • 대한기계학회논문집
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    • 제14권6호
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    • pp.1464-1473
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    • 1990
  • Optimal design parameters are estimated from the sensitivity function and performance index variation. Suspension design modification for performance improvement and basic materials for practical applications are presented. The linear quarter model of a vehicle suspension is analyzed in order to represent the utilities of sensitivity analysis, and sensitivity function is determined in the frequency domain. The change of frequency response function is predicted, which depends on the design parameter variation and the property is verified by computer simulation. As an investigation results of sensitivity function for the vibrational amplitude of sprung mass to road profile input, it is shown that the most sensitive parameters are the suspension damping and the suspension stiffness. In order to identify the effects of these two parameters to the performance of suspension system, the performance index variation according to the changes of parameters is considered and then optimal design parameters are determined. It is verified that the system response is improved noticeably in the both of frequency and time domain after the design modification with the optimal parameters.

유전 알고리즘을 이용한 현가장치의 기구학적 최적설계 (Optimum Design of Suspension Systems Using a Genetic Algorithm)

  • 이덕희;김태수;김재정
    • 한국자동차공학회논문집
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    • 제8권5호
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    • pp.138-147
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    • 2000
  • Vehicle suspension systems are parts which effect performances of a vehicle such as ride quality, handing characteristics, straight performance and steering effort etc. Kinematic design is a decision of joints` position for straight performance and steering effort. But, when vehicle is rebounding and bumping, chang of joints` displacement is nonlinear and a surmise of straight performance and steering effort at that joints` position is difficult. So design of suspension systems is done through a inefficient method of tried-and-error depending on designer`s experience. In this paper, kinematic design of suspension systems was done through the optimal design using a genetic algorithm. For this optimal design, the function for quantification of straight performance and steering effort was made, and the kinematic design method of suspension systems having this function as the objective function was suggested.

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Optimal design of an electro-pneumatic automatic transfer system

  • Um, Taijoon
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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    • pp.71-75
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    • 1994
  • This paper presents a method of optimal design of an automatic transfer system which is controlled by the electro-pneumatic servo scheme. The electro-pneumatic automatic transfer system can move parts to desired points or displace defective parts. The dynamic performance of the system can be examined by observing the behavior of the output. The output of the servo control system is the motion of the cylinder, pneumatic actuator. The dynamic performance of the cylinder is governed by the parameters of the components of the entire system. The optimal design can be accomplished by selecting of the parameters such that the desired dynamic performance of the cylinder is obtained. The optimal set of parameters might be obtained through the repeated simulations. Repeated simulations, however, is not effective to determine the optimal set of parameters since the set of parameters is large. This paper presents modeling, application of an optimization method, and the numerical results. The optimization algorithm utilizes the concept of the conjugate gradient method. The results show that the suggested optimization scheme can render faster convergence of iteration compared to other method based on an algebraic optimization method and can reduce the design efforts.

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점성 감쇠기를 이용한 인접 비대칭 강성 구조물의 내진보강 최적설계 (Optimal Seismic Reinforcement Design of Adjacent Asymmetric-Stiffness Structures with Viscous Dampers)

  • 성은희
    • 한국안전학회지
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    • 제37권6호
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    • pp.60-70
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    • 2022
  • This paper proposes an optimal design method of a seismic reinforcement system for the seismic performance of adjacent asymmetric-stiffness structures with viscous dampers. The first method considers plan asymmetry for efficient seismic reinforcement, and evaluates the seismic performance of optimal design applied to two cases of modeling: adjacent stiffness-asymmetric structures and adjacent stiffness-symmetric structures. The second method considers the response of asymmetric structures to derive the optimal objective function, and evaluates seismic efficiency of the objective function applied to two cases of responses: horizontal displacement and torsion. Numerical analyses are conducted on 7- and 10-story structures with a uni-asymmetric-stiffness plan using six cases of historic earthquakes, normalized to 0.4g. The results indicate that the seismic performance is excellent as modeled by adjacent asymmetric-stiffness structures and how much horizontal displacement is applied as the objective function.

CFD 연성해석과 유전자 알고리즘을 이용한 실내 열환경 최적설계에 관한 연구 (Optimal Design for Indoor Thermal Environment based on CFD Simulation and Genetic Algorithms)

  • 김태연;이윤규
    • 설비공학논문집
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    • 제16권2호
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    • pp.111-120
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    • 2004
  • The optimal design method of indoor thermal environment using CFD coupled simulation and genetic algorithms (GA) is developed in this study. CFD could analyze the thermal environment considering the distribution of temperature, velocity, etc. in a room. Therefore, It would be appropriate to use CFD for the optimal design method considering their distribution. In this paper, the optimal design means the most appropriate boundary conditions of the room among the conditions where the design target of indoor therm environment is achieved. Two step optimal indoor thermal environment design method is proposed. It includes the GA for searching the optimal indoor thermal environment design. To examine the performance of this method, the optimal design of hybrid ventilation system, which uses the natural cross ventilation and the radiation-cooling panel is conducted. The optimal design which satisfies the design target (thermal comfort, minimum cooling load, minimum vertical temperature difference) is found using two step optimal design method.

외란을 고려한 냉동시스템의 최적 PI 제어기 설계 (Optimal PI Controller Design for Refrigeration System Considering Disturbance)

  • 정석권;홍기학
    • 설비공학논문집
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    • 제25권2호
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    • pp.85-93
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    • 2013
  • The proportional plus integral(PI) feedback control manner has been used in many general industrial fields such as refrigeration system because of its simple design process and favorable control performance. This paper deals with optimized PI controller design of the refrigeration system based on evaluation functions such as integrated absolute error(IAE). The suggested optimal PI gains can be easily calculated by a simple program and the optimal controllability satisfying the evaluation function can be assured. Furthermore, at the initial step of controller design, the suggested optimal gain is able to reflect some noise disturbances caused by an inverter which drives variable speed compressors. The validity of the suggested optimal gain is investigated by some simulations and experiments to verify its efficiency. From the results of comparing control performance between the optimal PI controller based on the evaluation function and the PI controller designed by the Matlab tuner which was known as the most popular gain tuner, the optimal PI controller showed more desirable control performance especially in transient responses.

최적 축류팬 개발을 위한 통합공정 (설계, 시제품제작, 측정, 금형가공, 사출, 조립) (Integrated Process for Development of an Optimal Axial Flow Fan (Design, RP, Measurement, Injection Molding, Assembly))

  • 박성관;최동규
    • 한국CDE학회논문집
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    • 제3권3호
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    • pp.201-209
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    • 1998
  • To develop timely an optimal fan, a design system and a new manufacturing process used step by step have to be integrated. A small sized optimal fan for refrigerators, that was the goal on this project, was developed by the following principal processes. All processes are technologically linked in many directions: The existing fan was measured through reverse engineering. The measured data was used for the basic source of 3D design. The performance tests were carried and used as the data for the evaluation of the existing fan. Flow analysis by FANS-3D/sup [1]/ was performed at the given information (pressure drop and flow rate) to find out the configuration of optimal fan design. The flow patterns were investigated to measure the performance of fan through numerical experiment. The grid point data obtained by the above analysis turned into 3D high efficiency fan model by using CATIA. The product was manufactured by RP process (SLS, SLA) and tested the characteristic curves of the developed fan to compare with the existing fan. The modification of fan design were all examined to see any change in performance and checked to find any deficiency in assembling the fan into a duct. After the plastics flow analysis of the injection molding cycle to ensure acceptable quality fan, an optimal mold was processed by using tool-path for the newly designed fan.

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설계변수들의 상호효과를 고려한 Flextensional 트랜스듀서의 최적설계 (Optimal Design of a Flextensional Transducer Considering All the Cross-coupled Effects of the Design Variables)

  • 강국진;노용래
    • 한국소음진동공학회논문집
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    • 제13권5호
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    • pp.364-374
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    • 2003
  • The performance of an acoustic transducer is determined by the effects of many design variables. and mostly the influences of these design variables are not linearly independent of each other To achieve the optimal performance of an acoustic transducer, we must consider the cross-coupled effects of the design variables. In this study with the FEM. we analyzed the variation of the resonance frequency and sound pressure of a flextensional transducer in relation to Its design variables. Through statistical multiple regression analysis of the results, we derived functional forms of the resonance frequency and sound pressure in terms of the design variables, and with which we determined the optimal structure of the transducer by means of a constrained optimization technique, SQP-PD. The proposed method can reflect all the cross-coupled effects of multiple design variables, and can be utilized to the design of general acoustic transducers.

변위계수법을 활용한 최적 내진 성능기반 설계기법 개발 (Development of Optimal Performance based Seismic Design Method using Displacement Coefficient Method)

  • 이현국;권윤한;박효선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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    • pp.103-110
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    • 2004
  • Recently, performance based seismic design (PBSD) methods in numerous forms have been suggested and widely studied as a new concept of seismic design. The PBDSs are far from being practical due to complexity of algorithms resided in the design philosophy In this paper, optimal seismic design method based on displacement coefficient method (DCM) described in FEMA 273 is developed. As an optimizer simple genetic algorithms are used for implementations. In the optimization problem formulated in this paper, strength design criteria, stiffness design criteria, and nonlinear response criteria specified in DCM are included in design constraints. The optimal performance based design(OPBD) method is applied to seismic design of a 9-story two-dimensional steel frame structures.

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2차원 철골 구조물의 최적 성능기반 내진설계법 개발 (Development of the Optimal Performance Based Seismic Design Method for 2D Steel Moment Resisting Frames)

  • 권봉근;이현국;권윤한;박효선
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.636-643
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    • 2005
  • Recently, performance based seismic design (PBSD) methods have been suggested in numerous forms and widely studied as a new concept of seismic design. The PBDSs are far from being practical method due to complexity of algorithms resided in the design philosophy. In this paper, optimal seismic design method based on displacement coefficient method (DCM) described in FEMA 273 is developed. As an optimizer simple genetic algorithms are used for implementations. In the optimization problem formulated in this Paper, strength design criteria stiffness design criteria, and nonlinear response criteria specified in DCM are included in design constraints. The optimal performance based design(OPBD) method is applied to seismic design of a 3-story two-dimensional steel frame structures.

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