• 제목/요약/키워드: disturbances

검색결과 2,782건 처리시간 0.028초

모델 불확실성을 가지는 로봇 시스템을 위한 지능형 슬라이딩 모드 제어 (Intelligent Sliding Mode Control for Robots Systems with Model Uncertainties)

  • 유성진;최윤호;박진배
    • 제어로봇시스템학회논문지
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    • 제14권10호
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    • pp.1014-1021
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    • 2008
  • This paper proposes an intelligent sliding mode control method for robotic systems with the unknown bound of model uncertainties. In our control structure, the unknown bound of model uncertainties is used as the gain of the sliding controller. Then, we employ the function approximation technique to estimate the unknown nonlinear function including the width of boundary layer and the uncertainty bound of robotic systems. The adaptation laws for all parameters of the self-recurrent wavelet neural network and those for the reconstruction error compensator are derived from the Lyapunov stability theorem, which are used for an on-line control of robotic systems with model uncertainties and external disturbances. Accordingly, the proposed method can not only overcome the chattering phenomenon in the control effort but also have the robustness regardless of model uncertainties and external disturbances. Finally, simulation results for the five-link biped robot are included to illustrate the effectiveness of the proposed method.

종속 퍼지 제어기 설계 (Design of Cascaded Fuzzy Controller)

  • 정경권;류태욱;엄기환;이정훈;이용구;손동설
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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    • pp.185-188
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    • 2001
  • In this paper, a cascade fuzzy control method is proposed, which presents a robustness of the effect of disturbances, and in which the number of rules of the controller increase linearly instead of exponentially with the number of input variables. The proposed fuzzy control method is composed of cascade structure. Each stage has a state and a change of state, and one consequent control variable, and previous consequent control variable is an input of next stage. Simulation of the proposed controller, which is applied to the linear and nonlinear system as SISO (single-input single-output) system, showed that the proposed control method has a good control performance and robustness of disturbances compared with a conventional fuzzy control method.

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Control Strategy for Buck DC/DC Converter Based on Two-dimensional Hybrid Cloud Model

  • Wang, Qing-Yu;Gong, Ren-Xi;Qin, Li-Wen;Feng, Zhao-He
    • Journal of Electrical Engineering and Technology
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    • 제11권6호
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    • pp.1684-1692
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    • 2016
  • In order to adapt the fast dynamic performances of Buck DC/DC converter, and reduce the influence on converter performance owing to uncertain factors such as the disturbances of parameters and load, a control strategy based on two-dimensional hybrid cloud model is proposed. Firstly, two cloud models corresponding to the specific control inputs are determined by maximum determination approach, respectively, and then a control rule decided by the two cloud models is selected by a rule selector, finally, according to the reasoning structure of the rule, the control increment is calculated out by a two-dimensional hybrid cloud decision module. Both the simulation and experiment results show that the strategy can dramatically improve the dynamic performances of the converter, and enhance the adaptive ability to resist the random disturbances, and its control effect is superior to that of the current-mode control.

강인성 제어 시스템과 구조 시스템의 통합 최적 설계 (Combined Design of Robust Control System and Structure System)

  • 박중현
    • 동력기계공학회지
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    • 제7권4호
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    • pp.38-43
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    • 2003
  • This paper proposes an optimum design problem of structural and control systems. taking a 3-D truss structure as an example. The structure is supposed to be subjected to initial static loads and time-varying disturbances. The structure is controlled by a state feedback $H_{\infty}$ controller to suppress the effect of the disturbances. The design variables are the cross sectional areas of truss members. The structural objective function is the structural weight. As the control objective, we consider two types of performance indices. The first function represents the effect of the initial loads. The second one is the norm of the feedback gain. These objective functions are in conflict with each other. Then, first, two control objective functions are transformed into one control objective by the weighting method. Next, the structural objective is treated as the constraint. By introducing the second control objective which considers the magnitude of the feedback gain, we can per limn the design which is robust in modeling errors.

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상태 관측기를 이용한 자기-동조 적응 제어 (Self-Tuning Adaptive Control Using State Observer)

  • 김윤호;윤병도;오기홍
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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    • pp.223-226
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    • 1991
  • In this paper, the problem of designing on adaptive controller for dc drives using state observers, which is operated under varying load conditions, is addressed. A robust self-tuning controller that can track a constant reference and reject constant load disturbances is also studied. This scheme is very attractive since the estimates of system parameters are available in real time. Parameter estimation is based on the recursive least squares method and the control algorithm of the pole placement technique. Also, state observer systems are applied. State observer systems are required to estimate the states quickly and exactly without being affected by the disturbances.

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시간-주파수 해석 기법을 이용한 특징벡터 추출 및 전력 외란 신호 식별에의 응용 (Feature Vector Extraction using Time-Frequency Analysis and its Application to Power Quality Disturbance Classification)

  • 이주영;김기표;남상원
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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    • pp.619-622
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    • 2001
  • In this paper, an efficient approach to classification of transient and harmonic disturbances in power systems is proposed. First, the Stop-and-Go CA CFAR Detector is utilized to detect a disturbance from the power signals which are mixed with other disturbances and noise. Then, (i) Wigner Distribution, SVD(Singular Value Decomposition) and Fisher´s Criterion (ii) DWT and Fisher´s Criterion, are applied to extract an efficient feature vector. For the classification procedure, a combined neural network classifier is proposed to classify each corresponding disturbance class. Finally, the 10 class data simulated by Matlab power system blockset are used to demonstrate the performance of the proposed classification system.

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유전 알고리즘을 이용한 강인한 $H_\infty$-QFT PSS 설계에 관한 연구 (A Study on Design of Robust $H_\infty$-QFT PSS Using Genetic Algorithm)

  • 정형환;이정필;박희철;왕용필
    • 대한전기학회논문지:전력기술부문A
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    • 제52권7호
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    • pp.371-380
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    • 2003
  • In this paper, a new design method of H$H_\infty$-Qn PSS using genetic algorithm(GA) is proposed to efficiently damp low frequency oscillations despite the uncertainties and various disturbances of power systems. The selection method of evaluation function is proposed for selecting the robust PSS parameters. All QFT boundaries are satisfied automatically and H$H_\infty$-norm is minimized simultaneously without trial and error procedure. The eigenvalues and the damping ratio of dominant oscillation mode are investigated to evaluate performance of designed controller for one machine infinite bus system. A disturbance attenuation performance is investigated through singular value bode diagram of the system. Dynamic characteristics are considered to verify robustness of the proposed PSS by means of nonlinear simulations under various disturbances for various operating conditions. The results show that the proposed PSS is more robust than conventional PSS.

레이저 크로스빔 속도계에 대한 대기교란 효과 (Effects of atmospheric turbulence on the laser cross-beam velocimeter)

  • 성평식
    • 한국컴퓨터산업학회논문지
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    • 제6권2호
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    • pp.259-264
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    • 2005
  • 입사빔의 진폭과 위상에 관한 대기교란의 영향을 고려하며 크로스빔 레이저 속도계에 대한 광전류 상관함수의 표현식을 프린지 모델을 이용하여 유도 하였고, 그 결과 대기의 교란 입자가 프린지 모델에서 이동하는 광 전류 상관함수의 정현변화는 교란 상관함수로 부터 입자의 속도(산란입자는 속도V를 가져야 하는 것으로 가정하였다.)를 결정하는데 크게 영향을 주지 않는다.

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상류측 교란요소가 스윙형 역지밸브의 성능에 미치는 영향 (The Effect of Upstream Disturbances on the Performance of Swing Check Valves)

  • 송석윤;유성연
    • 한국유체기계학회 논문집
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    • 제10권1호
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    • pp.41-48
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    • 2007
  • The effect of the upstream flow conditions on the disc stability of the swing check valves was investigated at various upstream flow disturbance sources and distances from the tested check valves. The experimental loop was designed and installed to measure the disc positions, disc back stop load, and differential pressure at flow velocities lot 3 inch and 6 inch swing check valves. The selected disturbance sources are elbow and globe valve. The effect of the disc fluctuation is different depending on the type of disturbance and the distance between the disturbance and the check valve. Disturbances generated by elbow and globe valve located upstream from check valve create greater and more violent disc motion than uniform flow.

Improvement of Control Performance by Data Fusion of Sensors

  • Na, Seung-You;Shin, Dae-Jung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권1호
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    • pp.63-69
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    • 2004
  • In this paper, we propose a general framework for sensor data fusion applied to control systems. Since many kinds of disturbances are introduced to a control system, it is necessary to rely on multisensor data fusion to improve control performance in spite of the disturbances. Multisensor data fusion for a control system is considered a sequence of making decisions for a combination of sensor data to make a proper control input in uncertain conditions of disturbance effects on sensors. The proposed method is applied to a typical control system of a flexible link system in which reduction of oscillation is obtained using a photo sensor at the tip of the link. But the control performance depends heavily on the environmental light conditions. To overcome the light disturbance difficulties, an accelerometer is used in addition to the existing photo sensor. Improvement of control performance is possible by utilizing multisensor data fusion for various output responses to show the feasibility of the proposed method in this paper.