• Earthquakes and Structures
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• 제6권2호
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• pp.217-235
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• 2014

In this paper, different feedback control strategies are presented for active seismic control using proportional-integral-derivative (PID) type controllers. The parameters of PID controller are found by using an numerical algorithm considering time delay, maximum allowed control force and time domain analyses of shear buildings under different earthquake excitations. The numerical algorithm scans combinations of different controller parameters such as proportional gain ($K_p$), integral time ($T_i$) and derivative time ($T_d$) in order to minimize a defined response of the structure. The controllers for displacement, velocity and acceleration feedback control strategies are tuned for structures with active control at the first story and all stories. The performance and robustness of different feedback controls on time and frequency responses of structures are evaluated. All feedback controls are generally robust for the changing properties of the structure, but acceleration feedback control is the best one for efficiency and stability of control system.

• Transactions on Electrical and Electronic Materials
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• 제15권6호
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• pp.297-304
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• 2014

Due to the nonlinearity and complexity of the three-phase photovoltaic inverter, we propose an intelligent control based on fuzzy logic and the classical proportional-integral-derivative. The feedback linearization method is applied to cancel the nonlinearities, and transform the dynamic system into a simple and linear subsystem. The system is transformed from abc frame to dq0 synchronous frame, to simplify the state feedback linearization law, and make the close-loop dynamics in the equivalent linear model. The controls improve the dynamic response, efficiency and stability of the three-phase photovoltaic grid system, under variable temperature, solar intensity, and load. The intelligent control of the nonlinear characteristic of the photovoltaic automatically varies the coefficients $K_p$, $K_i$, and $K_d$ under variable temperature and irradiation, and eliminates the oscillation. The simulation results show the advantages of the proposed intelligent control in terms of the correctness, stability, and maintenance of its response, which from many aspects is better than that of the PID controller.

• 센서학회지
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• 제29권6호
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• pp.412-419
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• 2020

In this study, a PID control method for sweeping automatic linearization of a wavelength swept laser is proposed. First, the closedloop transfer function embodying the PID control is derived. Through the simulation of the function, K_p = 0.022, K_i = 0.008, K_d = 0.002 were obtained as the best PID coefficients for fast linear sweeping. The performance test using the PID coefficients showed that linear sweeping was held up well with a 98.7% decrement in nonlinearity after the 10th feedback, and 45 nm sweeping range, 1 kHz sweeping frequency, and 8.8 mW average optical power were obtained. The equipment consists of a fiber Bragg grating array, an optical-electronic conversion circuit, and a LabVIEW FPGA program. Every 5s, automatic feedback and PID control generate a new compensated waveform and produce a better linear sweeping than before. Compared with nonlinear sweeping, linear sweeping can reduce the cumbersome and time-consuming recalibration processes and produce more accurate measurement results.

• 한국정밀공학회지
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• 제14권7호
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• pp.29-38
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• 1997

A closed-loop system modeling of an active/semiactive suspension system has been accomplished through an artificial neural network. A 7DOF full model as a system's equation of motion has been derived and an output feedback linear quadratic regulator has been designed for control purpose. A training set of a sample data has been obtained through a computer simulation. A 7DOF full model with LQR controller simulated under several road conditions such as sinusoidal bumps and rectangular bumps. A general multilayer perceptron neural network is used for dynamic modeling and target outputs are fedback to the a layer. A backpropagation method is used as a training algorithm. Model validation of new dataset have been shown through computer simulations.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.348-354
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• 1999

본 논문에서는 산업 현장에서 일반적으로 많이 사용되고 있는 PID 제어기의 비례, 적분, 미분 파라미터를 다층 신경회로망을 이용하여 자동으로 동조하는 방법을 제안한다. 제안한 방식은 자기 궤환 뉴런을 가진 다층 신경회로망이 플랜트의 입력과 출력을 이용하여 PID 제어기의 파라미터들을 학습에 의하여 자동 동조한다. 다층 신경회로망은 자기 궤환 뉴런을 이용하여 입력층, 은닉층, 출력층의 3층으로 구성하고, 출력은 3개의 값을 갖는다. 이것은 PID 제어기의 비례(P), 적분(I), 미분(D) 파라미터로 사용된다. 이 값들은 특정한 값으로 고정되는 것이 아니라 제어 수행 과정 중에서도 다층 신경회로망의 학습에 의해 계속 변화된다. DC 서보 모터와 단일 관절 매니퓰레이터를 대상으로 시뮬레이션을 통해서 제안한 방식의 유용성을 확인한다.

• 한국추진공학회지
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• 제9권3호
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• pp.74-84
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• 2005

본 논문에서는 AMESim(상용 소프트웨어)을 이용, 개방형 터보펌프식 엔진시스템을 모델로 하여 산업용 제어밸브를 적용한 시스템의 특성을 미리 확인하였다. 그 결과물을 토대로 하여 앞으로 발사체 제어밸브 개발할 계획이며, 밸브와 연계된 제어 및 밸브시험을 위한 설비 특성을 예측해 보았다. 시스템시험을 위해 장착할 각 산업용 제어밸브의 PID 값을 찾고자 하였으며, PI 및 PID 제어 방식을 이용하여 제어밸브의 과도 및 정상상태의 유동특성을 비교분석하였다. 제어밸브를 이용하여 추력제어 및 TDS 구현을 목적으로 하는 밸브설계와 시스템의 종합 모사시험을 위한 설비의 설계 조건을 또한 제시하였다.