• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.224-224
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• 2000

Biaffine Matrix Inequalities(BIs) are known to give more general and flexible frameworks in control designs than Linear Matrix Inequalities(LMIs). However, BMIs are nonconvex constraints and very difficult to solve. In this paper, BMI problems are solved using Evolution Strategy(ES). Numerous BMI problems are solved to verify performances of ES solver for BMI problems and compared with those of Genetic Algorithms and Branch-and-Cut algorithm.

• 전력전자학회논문지
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• 제7권4호
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• pp.384-394
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• 2002

본 논문은 기존의 정전력 제어 대신에 용접품질을 향상시키기 위해 새로운 제어기법을 제안하였다. 제안된 방식을 구현하기 위해 미분기하학 이론을 근거로 한 비선형 피드백 선형화 기법을 이용하여 스폿용접 시스템을 선형시스템으로 한 후 진화전략을 이용하여 PI제어기의 최적 이득을 얻는다. 진화전략은 제어파라미터 최적화 문제를 풀기 위한 방법으로 자연진화의 원리를 모방한 알고리즘이다. 시뮬레이션과 실험결과는 진화전략에 의한 가변전력 제어의 성능이 기존의 제어방법보다 훨씬 더 우수하다는 것을 보여준다.

• Smart Structures and Systems
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• 제14권1호
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• pp.17-37
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• 2014

In this study, four widely accepted and used variants of Evolution Strategies (ES) are adapted and applied to the output-error state-space identification problem. The selection of ES is justified by prior strong indication of superior performance to similar problems, over alternatives like Genetic Algorithms (GA) or Evolutionary Programming (EP). The ES variants that are being tested are (i) the (1+1)-ES, (ii) the $({\mu}/{\rho}+{\lambda})-{\sigma}$-SA-ES, (iii) the $({\mu}_I,{\lambda})-{\sigma}$-SA-ES, and (iv) the (${\mu}_w,{\lambda}$)-CMA-ES. The study is based on a six-degree-of-freedom (DOF) structural model of a shear building that is characterized by light damping (up to 5%). The envisaged analysis is taking place through Monte Carlo experiments under two different excitation types (stationary / non-stationary) and the applied ES are assessed in terms of (i) accurate modal parameters extraction, (ii) statistical consistency, (iii) performance under noise-corrupted data, and (iv) performance under non-stationary data. The results of this suggest that ES are indeed competitive alternatives in the non-linear state-space estimation problem and deserve further attention.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1561_1562
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• 2009

In this paper, designed triple-band antenna of PIFA(Planar Inverted-F Antenna) structure with U-slot. We designed optimal PIFA structure using Evolution Strategy(ES) about two U-slot parameters. We materialized API(Application Program Interface) about EM simulator and Excel using VB(Visual Basic). The result of ES for triple-band PIFA are resonant frequency of 430MHz, 910.5MHz, 2458.5MHz.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.9-11
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• 1995

In this paper, tile squirrel case induction motors required multi-objective function are designed. As the objective function of the optimization program, we select the linear combination of loss and mass of motors by using weighting factors. Optimization process is performed by using the evolution strategy (ES). ES is the algorithm that can find the global minimum. To verify validity of the proposed method, a sample design is tried.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.6-8
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• 1996

The multiobjective optimization is presented for the optimal design of induction motors. The aim of design is to find an optimized induction motor in terms of both the efficiency and the mass. The efficiency and the mass are linearly combined using the weighting factors. Optimization process is performed by using the improved (1+1) evolution strategy (ES). ES is the algorithm that can find the global minimum. To verify the validity of the proposed method. the method is applied to a sample design.

• 제어로봇시스템학회논문지
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• 제7권3호
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• pp.209-217
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• 2001

In this paper, we propose a linear quadratic regulator(LQR) controller design for the active suspension using evolution strategy(ES) and neural network. We can improve the inherent suspension problem, the trade-off between ride quality and suspension travel by selecting appropriate weight in the LQR-objective function. Since any definite rules for selecting weights do not exist, we replace the designers trial-and-error method with ES that is an optimization algorithm. Using the ES, we can find the proper control gains for selected frequencies, which have major effects on the vibrations of the vehicle. The relationship between the frequencies and proper control gains are generalized by use of the neural networks. When the vehicle is driven, the trained neural network is activated and provides the proper gains for operating frequencies. And we adopted double sky-hook control to protect car component when passing large bump. Effectiveness of our design has been shown compared to the conventional sky-hook controller through simulation studies.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.177-180
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• 1996

Fuzzy control systems depend on a number of parameters such as the shape or magnitude of the fuzzy membership functions, etc. Conventional fuzzy reasoning method can not be easily applied to the multi-input multi-output(MIMO) system due to the large number of rules in the rule base. Recently Z. Cao et al have proposed a New Fuzzy Reasoning Method(NFRM) which turned out to be superior to Zadeh's FRM. We have extended the NFRM to handle the MIMO system. However, it is difficult to choose a proper relation matrix of the NFRM. Therefore, we have modified the evolution strategy(ES), which is one of the optimization algorithms, to do efficiently the tuning operation for the extended NFRM. Finally we applied the extended NFRM with the modified ES to tracking control of robot manipulator.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.531-533
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• 1997

PI(proportional-integral) controller has been extensively used in the industrial field. But in practicle case, it is difficult to tune PI gains. Evolution Strategy(ES) is used as an effective search algorithm in optimization programs. In this paper we proposed a PI controller for Spot welder system using ES with varying search space. ES with varying search space which depends on fitness values at each generation is used to tune PI control parameters. Simulation results show the proposed algorithm has accurate and robust performance with effective search ability.

• 전기학회논문지
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• 제63권12호
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• pp.1661-1666
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• 2014

In this paper, a compact planar ultra wideband (UWB, 3.1~10.6GHz) multiple-input multiple-output (MIMO) antenna is proposed. This antenna consists of two monopole planar UWB antennas and T-shaped stub decoupling between two antennas. The T-shaped stub improve the isolation characteristic at the wide band. The evolution strategy(ES) algorithm is employed to optimized design. As a result, optimized antenna has a return loss less than -10dB and the isolation less than -15dB from 3.1GHz to 10.6GHz. During the optimization process, the antenna gain is enhanced at lower band and the envelope correlation coefficient(ECC) is lower than 0.003.