• 제목/요약/키워드: uncertain dynamic system

검색결과 154건 처리시간 0.028초

LQG/LTR 방법을 이용한 터렛 서보시스템의 강인한 제어기 설계 (A Design of Robust Controller for the Turret Servo System Using LQG/LTR Method)

  • 김종화;허남수;이만형
    • 한국정밀공학회지
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    • 제6권2호
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    • pp.88-97
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    • 1989
  • In general turret servo system is subject to influnces by disturbances and uncertain modeling errors, which result from large dynamic characteristics and high-spedd operation. In this paper the influences of such disturbances and modeling errors are analyzed quali- tatively for the linerar approximation model of turret servo system, and then LQG/LTR control theory is applied to linear approximation model in order to design a controller which satisfies robustness/stability for the modeling errors. Finally the performance and robustness of designed controller for the given plant are verified through the simulation.

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출력의 미분항을 사용하지 않는 적응 관측기 설계 방법 (Design of an Adaptive Observer without Using Output Derivative Measurements)

  • 손영익;심형보;백주훈;조남훈
    • 대한전기학회논문지:시스템및제어부문D
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    • 제53권6호
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    • pp.395-401
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    • 2004
  • By using an adaptive algorithm, together with an additional dynamic system, this paper proposes a new approach to design of a state observer for a class of uncertain systems. We enlarge the class of linear systems from the canonical form of [1] by proposing an adaptive observer that allows unknown parameters to affect those unmeasured states. The result is based on a recent result which presents a design algorithm for an additional system to replace output derivative measurements with the additional dynamics. A numerical example illustrates the design procedure of the state observer.

Stochastic intelligent GA controller design for active TMD shear building

  • Chen, Z.Y.;Peng, Sheng-Hsiang;Wang, Ruei-Yuan;Meng, Yahui;Fu, Qiuli;Chen, Timothy
    • Structural Engineering and Mechanics
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    • 제81권1호
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    • pp.51-57
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    • 2022
  • The problem of optimal stochastic GA control of the system with uncertain parameters and unsure noise covariates is studied. First, without knowing the explicit form of the dynamic system, the open-loop determinism problem with path optimization is solved. Next, Gaussian linear quadratic controllers (LQG) are designed for linear systems that depend on the nominal path. A robust genetic neural network (NN) fuzzy controller is synthesized, which consists of a Kalman filter and an optimal controller to assure the asymptotic stability of the discrete control system. A simulation is performed to prove the suitability and performance of the recommended algorithm. The results indicated that the recommended method is a feasible method to improve the performance of active tuned mass damper (ATMD) shear buildings under random earthquake disturbances.

Estimating peak wind load effects in guyed masts

  • Sparling, B.F.;Wegner, L.D.
    • Wind and Structures
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    • 제10권4호
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    • pp.347-366
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    • 2007
  • Guyed masts subjected to turbulent winds exhibit complex vibrations featuring many vibration modes, each of which contributes to various structural responses in differing degrees. This dynamic behaviour is further complicated by nonlinear guy cable properties. While previous studies have indicated that conventional frequency domain methods can reliably reproduce load effects within the mast, the system linearization required to perform such an analysis makes it difficult to relate these results directly to corresponding guy forces. As a result, the estimation of peak load effects arising jointly from the structural action of the mast and guys, such as leg loads produced as a result of guy reactions and mast bending moments, is uncertain. A numerical study was therefore undertaken to study peak load effects in a 295 m tall guyed mast acted on by simulated turbulent wind. Responses calculated explicitly from nonlinear time domain finite element analyses were compared with approximate methods in the frequency domain for estimating peak values of selected responses, including guy tension, mast axial loads and mast leg loads. It was found that these peak dynamic load effects could be accurately estimated from frequency domain analysis results by employing simple, slightly conservative assumptions regarding the correlation of related effects.

신경회로망 보상기를 이용한 무인헬리콥터의 비선형적응제어 (Nonlinear Adaptive Control of Unmanned Helicopter Using Neural Networks Compensator)

  • 박범진;홍창호
    • 한국항공우주학회지
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    • 제38권4호
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    • pp.335-341
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    • 2010
  • PD 제어기 기반으로 설계된 무인헬리콥터의 내부루프 제어기의 성능을 향상시키기 위 하여 한 개의 신경회로망이 적용되었다. 오차방정식의 응답특성 기반으로 설계된 PD 제어기는 운동모델의 비선형성에 의해 성능이 저하된다. 이러한 비선형성은 운동모델로부터 변형된 운동 역변환 모델(Modified Dynamic Inversion Model, MDIM)로 분리되었고 신경회로망의 출력에 의해 보상되었다. 신경회로망의 학습에는 제어기 안정성 보장을 위하여 리야프노프의 직접방법(Lyapunov's direct method)으로부터 유도된 온라인 가중치 적응법칙이 이용되었다. 신경회로망에 의한 PD제어기의 성능향상은 비선형성을 갖고 있는 무인헬리콥터의 수치시뮬레이션 결과로 보였다.

초소형 광자기 드라이브용 서스펜션의 동특성 해석 (Dynamic Analysis of Suspension for Small Form Factor MO Drive)

  • 홍어진;오우석;박노철;양현석;박영필
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.406-411
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    • 2003
  • One of the trends on information storage device is focused on the development of micro-optical devices with OFH (Optical Flying Head). Many different types of sliders for OFH and optical component systems have been introduced in the literature. However, the important issue on the mechanical system, which consists of suspension, swing arm and VCM (Voice Coil Motor) part has not been discussed up to date. In this research, we analyses the suspension, which is used for the small form factor MO drive. The analysis is in process two ways. One is probabilistic analysis, another is dynamic shock analysis. Probabilistic analysis is a technique you can use to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can and out how much the results of a finite elements analysis are affected by uncertainties in the model. Dynamic shock analysis is used for the mobile applications. The mechanical robustness of the suspension simulating the shock responses of a disk-suspension is proposed in this paper.

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조립용 로봇의 가변구조 적응제어 (Variable Structure Adaptive Control of Assembling Robot)

  • 한성현
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1997년도 춘계학술대회 논문집
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    • pp.131-136
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    • 1997
  • This paper represent the variable structure adaptive mode control technique which is new approach to implement the robust control of industrial robot manipulator with external disturbances and parameter uncertainties. Sliding mode control is a well-known technique for robust control of uncertain nonlinear systems. The robustness of sliding model controllers can be shown in contiuous time, but digital implementation may not preserve robustness properties because the sampling process limits the existence of a true sliding mode. the sampling process often forces the trajectory to oscillate in the neighborhood of the sliding surface. Adaptive control technique is particularly well-suited to robot manipulators where dynamic model is highly complex and may contain unknown parameters. Adaptive control algorithm is designed by using the principle of the model reference adaptive control method based upon the hyperstability theory. The proposed control scheme has a simple sturcture is computationally fast and does not require knowledge of the complex dynamic model or the parameter values of the manipulator or the payload. Simulation results show that the proposed method not only improves the performance of the system but also reduces the chattering problem of sliding mode control, Consequently, it is expected that the new adaptive sliding mode control algorithm will be suited for various practical applications of industrial robot control system.

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초소형 광자기 드라이브용 HGA의 신뢰성 및 충격 해석 (Probabllistic and Shock Analysis of Head-gimbal Assembly in Micro MO Drives)

  • 오우석;박노철;양현석;박영필;홍어진
    • 한국소음진동공학회논문집
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    • 제14권12호
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    • pp.1347-1353
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    • 2004
  • With respect to the researches of the optical flying head(OFH) , the head-gimbal assembly should be analyzed to guarantee the stable fabrication and the characteristics of shock resistance. The suitable design is proved through the Probabilistic analysis of the design parameters and material properties of the model. Probabilistic analysis is a technique that be used to assess the effect of uncertain input parameters and assumptions on your analysis model. Using a probabilistic analysis you can find out how much the results of a finite elements analysis are affected by uncertainties in the model. Another factor is analysis of the dynamic shock analysis. For the mobile application, one of the important requirements is durability under severe environmental condition, especially, resistance to mechanical shock. An important challenge in the disk recording is to improve disk drive robustness in shock environments. If the system comes in contact with outer shock disturbance. the system gets critical damage in head-gimbal assembly or disk. This paper describes probabilistic and dynamic shock analysis of head-gimbal assembly in micro MO drives using OFH slider.

복합조직강의 마찰용접부에 대한 동적파괴특성 (The study on dynamic fracture toughness of friction-welded M.E.F. dual phase steel)

  • 오세욱;유재환;이경봉
    • Journal of Welding and Joining
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    • 제7권3호
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    • pp.19-27
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    • 1989
  • Both the SS41 steel and the M.E.F(martensite encapsulated islands of frrite) dual phase steel made of SS41 steel by heat treatment were welded by friction welding, and then manufactured machinemade Vnotch standard Charpy impact specimens and precracked with a fatigue system at BM(base metal), HAZ(heat affected zone) and WZ(weld interface Zone). The impact test of them was performed with an instrumented impact test machine at a number of temperatures in constant loading velocity and the dynamic fracture characteristics were studied on bases of the absorbed energy, dynamic fracture toughness and fractography from the test. The results obtained are as follows; At the room temperature, the absorbed energy is HAZ.geq.WZ.geq.BM in case of the M.E.F. dual phase steel: BM.geq.HAZ.geq.WZ in case of the SS41 steel, HAZ.geq.BM.geq.WZ at the low temperature. The absorbed energy is decreased markedly with the temperature lowering; it is highly dependent on the temperature. The dynamic fracture toughness of the M.E.F. dual phase steel is HAZ.geq.WZ.geq.BM at the room temperature; BM.geq.WZ.geq.HAZ below-60.deg. C. Therefore the reliability of friction welding is uncertain at the low temperature(below-60.deg. C). The dynamic fracture toughness of the SS41 steel; HZA.geq.WZ.geq.BM at overall temperature region. The flaw formed by rotational upsetting pressure was shown y SEM; in this region. The absorbed energy per unit area and dynamic fracture toughness were low relative to other region.

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자기조직 시스템으로서의 건축환경 개념에 관한 연구 -자연과학적 패러다임을 중심으로- (The Architectural Environment as a Self-organizing System -Based on Paradigm of Natural Science-)

  • 김주미
    • 한국실내디자인학회논문집
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    • 제14호
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    • pp.63-73
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    • 1998
  • The aim of this study is to understand and redefine the nature of architectural environment within the paradigm of natural science. The chaos theory non-equilibrium thermodynamics theory self-organization of modern physics offer new insights to explain not only natural phenomena but also to define creative and dynamic architectural environment. First natural laws in modern physics like the arrow of time but is related not only with certainty but also possibility so nature is understood as a constantly changing process of evolution. Second the new architectural environment is defined as a kind of fluid and irreducible organic biosytem that cannot be fully understood by modernist idea of architecture. It is conceived of as a fluid constantly changing self-oraganizing system that consists of different situations events movements and programs in uncertain and irreducible time frame. Third insights and implications of natural science offer new language and strategy for design and the two disciplines can be understood as interdependent and co-evolving

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