• Smart Structures and Systems
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• 제8권5호
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• pp.449-470
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• 2011

During the last thirty years many structural control concepts have been proposed for the reduction of the structural response caused by earthquake excitations. Their research and implementation in practice have shown that seismic control of structures has a lot of potential but also many limitations. In this paper the importance of two practical issues, time delay and saturation effect, on the performance of controlled structures, is discussed. Their influence, both separately and in interaction, on the response of structures controlled by a modified pole placement algorithm is investigated. Characteristic buildings controlled by this algorithm and subjected to dynamic loads, such as harmonic signals and actual seismic events, are analyzed for a range of levels of time delay and saturation capacity of the control devices. The response reduction surfaces for the combined influence of time delay and force saturation of the controlled buildings are obtained. Conclusions regarding the choice of the control system and the desired properties of the control devices are drawn.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1991년도 추계학술발표회논문집
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• pp.53-58
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• 1991

This paper presents the speed control of DC motor based on deadbeat response method. Since 송 deadbeat response systems are characterized by the discrete time control, the instabiliby of the systems caused by saturation and time lag problems is inevitable. In order to release these problems, we propose a compensator utilizing the predictive control so that the fast response can be also achieved in the saturation state. Experimental results demonstrated that outputs are able to settle final values in on sampling time for unsaturated reference inputs. For saturated reference inputs, outputs take one sampling time after getting free from the saturation state. Further we are able to settle the fast response with suppressed overshoot by appling the predictive control.

• 한국결정성장학회지
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• 제12권6호
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• pp.288-291
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• 2002

We developed a new RF indirect-heating LPE furnace. The thermal gradient of our newly developed furnace is less than that of direct heating, and is as gentle as that of the resistance-heating LPE furnace. With this new furnace, the heating and/or cooling is faster than that of the resistance-heating furnace. Impurity-doped YIG film was grown from a $PbO-B_{2}O_{3}$, based flux on a (111) GGG substrate. To study the effect of the impurities on the MSSW threshold power and the saturation response time, we used two microstrip lines to excite and propagate the MSSW at 1.9 GHz. The MSSW threshold power and saturation response time was found to be related to the $\Delta$H.

• 전기의세계
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• 제26권6호
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• pp.55-58
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• 1977

This paper deals with the transient analysis of an amplidyne dc voltage regulating system under the following conditions: (1) assuming all the components of the system to be linear, (2) considering the effect of amplidyne saturation. The mathematical technique employed is state variables method. The calculated response curves are compared with the experimental results obtained on a practical system. The main results can be summerized as follows: 1) The effect of amplidyne saturation on the transient response of a dc voltage regulating system is to reduce the overshoot and setting time. 2) With the increase in level of the step reference voltage, the system response becomes apesiodic. 3) The steady output voltage is reduced appreciably compared to the linear case.

• 전자공학회논문지SC
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• 제42권1호
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• pp.13-21
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• 2005

본 논문에서는 시간지연과 입력포화를 갖는 카오스 시스템에 대한 퍼지 모텔 기반의 동기화 기법을 제안한다. 시간지연을 갖는 카오스 마스터 시스템과 슬레이브 시스템을 모델링하기 위해 Takagi-Sugeno(T-S) 퍼지 모델을 이용한다. 특히 슬레이브 시스템은 제어 입력이 제한되는 입력포화 특성을 갖는다고 가정한다. 선형 오차 피드백과 병렬 분상 보상(PDC) 방법에 따라 퍼지 카오스 동기화 시스템을 설계하고 동기화 오차 시스템의 국소 안정도 조건을 해석한다. 신호 전송 채널에는 시간지연이 항상 존재하므로 채널 시간지연 또한 고려한다. 입력포화와 시간지연을 갖는 퍼지 동기화 시스템의 국소 안정도에 대한 충분 조건은 Lyapunov-Krasovskii 이론을 적용하여 선형 행렬 부등식 (LMI) 문제의 해를 통해 얻어진다. 제안된 동기화 기법의 효과를 확인하기 위해서 모의 실험을 수행한다.

• Smart Structures and Systems
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• 제12권2호
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• pp.157-179
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• 2013

We present an approach, based on the state dependent Riccati equation, for designing non-collocated seismic response control strategies for buildings accounting for physical constraints, with particular attention to force saturation. We consider both cases of active control using general actuators and semi-active control using magnetorheological dampers. The formulation includes multi control devices, acceleration feedback and time delay compensation. In the active case, the proposed approach is a generalization of the classic linear quadratic regulator, while, in the semi-active case, it represents a novel generalization of the well-established modified clipped optimal approach. As discussed in the paper, the main advantage of the proposed approach with respect to existing strategies is that it allows to naturally handle a broad class of non-linearities as well as different types of control constraints, not limited to force saturation but also including, for instance, displacement limitations. Numerical results on a typical building benchmark problem demonstrate that these additional features are achieved with essentially the same control effectiveness of existing saturation control strategies.

• 한국세라믹학회지
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• 제34권4호
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• pp.429-435
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• 1997

The third order nonlinear optical susceptibilities, {{{{ chi }}(3), of the CuCl doped alumino-borosilicate glasses were measured by the two beam configuration DFWM method and the absorption saturation method, and the measured {{{{ chi }}(3) values were about 10-8 esu in both methods. The response time was estimated to be about 105ps from the time decay curve of the luminescence spectra obtained by time-correlated single-photon counting (TCSPC) method.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.76-84
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• 2001

Generally fuel injection system using solenoid have some problems between control signal and mechanical movement like as time lag. Main purpose of the present study is to help the design optimization of GDSI for real engine application. We have adopted two different solenoid driving circuit, namely saturation and pick-hold type and have investigated experimentally the current, needle force, needle opening duration and injection quantity. The pick-hold type driving circuit surpassed a saturation type in the response time and pression control of injection quantity. Accordingly, Using characterization data of operating factors such as time constant, driving force and so on, can be evaluated and adjusted to obtain an optimum injector performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.371-374
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• 1990

This paper presents the speed control of dc motor based on deadbeat response. The deadbeat response is that the output reaches the final value in the minimum possible settling time and stays there. This results demonstrate that the output reaches final value in one sampling time for the unsaturated region, and in one sampling time after getting free from the saturation state for the saturated region.

• 한국농공학회논문집
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• 제54권4호
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• pp.93-103
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• 2012

A suction-saturation control technique based on flow pump system was developed to investigate hydraulic properties in unsaturated soils. The flow pump system is designed based on the principle of the axis-translation technique and triaxial equipment, and gives the suction-time and suction-saturation curves, the primary relationship needed for interpreting the response of unsaturated soils and link between theory and the material properties in unsaturated soil mechanics. Using the suction-saturation control technique, suction-time relationship and soil-water retention curve (SWRC) during hydraulic hysteresis were investigated with different net confining pressures and porosities. Three types of soils-two sands and a silt were used in this paper. This paper showed the effect of the hysteresis on the SWRC due to different net confining pressures and porosities. This means that a careful decision must be made as to which condition is to be modeled, since the delicate difference of the conditions in physical modeling can cause the different experimental output.