• Title/Summary/Keyword: Feedback Structure

Search Result 954, Processing Time 0.034 seconds

Structure-Control Combined Optimal Design of 3-D Truss Structure Considering Intial State and Feedback Gain

  • Park, Jung-Hyen
    • Journal of Ocean Engineering and Technology
    • /
    • v.17 no.4
    • /
    • pp.66-72
    • /
    • 2003
  • This paper proposes an optimum, problematic design for structural and control systems, taking a 3-D truss structure as an example. The structure is subjected to initial static loads and time-varying disturbances. The structure is controlled by a state feedback H$_{\infty}$ controller which suppress the effects of disturbances. The design variables are the cross sectional areas of truss members. The structural objective function is the structural weight. For the control objective, we consider two types of performance indices, The first function represents the effect of the initial loads. The second function is the norm of the feedback gain, These objective functions are in conflict with each other but are transformed into one control objective by the weighting method. The structural objectives is treated as the constraint, By introducing the second control objective which considers the magnitude of the feedback gain, we can create a design to model errors.

Design of an Output Feedback Variable Structure Control System (출력궤환 가변구조 제어계의 설계에 관한 연구)

  • 이기상;조동식
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.41 no.8
    • /
    • pp.883-892
    • /
    • 1992
  • In order to remove the assumption of full state availability which is one of the major difficulties with the practical realization of variable structure control system (VSCS), an output feedback variable structure control scheme for multivariable systems is proposed. The proposed output feedback VSCS is composed of a switching surfaces with dynamic structure and a new output feedback control input that can be constructed by using conventional output feedback control input design methodologies. With the proposed scheme, the practical realization of VSCS for the systems with unmeasurable states and for high order systems that conventional schemes cannot be applied is possible. Simulation results show that proposed scheme is a viable method to achieve the desired control performance, for example, good transient response, robustness against process parameter variations and external disturbance without measuring all the state variables.

A New Robust Output Feedback Variable Structure Controller for Uncertain More Affine Nonlinear Systems with Mismatched Uncertainties and Matched Disturbance

  • Lee, Jung-Hoon
    • Journal of IKEEE
    • /
    • v.18 no.2
    • /
    • pp.206-213
    • /
    • 2014
  • In this note, a new robust nonlinear output feedback variable structure controller is first systematically and generally designed for the output control of more affine uncertain nonlinear systems with mismatched uncertainties and matched disturbance. A transformed integral output feedback sliding surface with a most simple form is applied in order to remove the reaching phase problems. The closed loop exponential stability and the existence condition of the sliding mode on the integral output feedback sliding surface is investigated with a corresponding output feedback control input in Theorem 1. For practical application the continuous implementation of the control input is made by the modified saturation function. The effectiveness of the proposed controller is verified through a design example and simulation study.

Feedback scope for fault detection and localization

  • Hunsang Jung;Park, Youngjin
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2002.10a
    • /
    • pp.32.6-32
    • /
    • 2002
  • The damage localization of the structural system using the natural frequency measurement only is proposed. The existing methods use the changes of mode shape, strain mode shape or curvature mode shape before and after the damage occurrence as these shapes carry the geometric information of the structure. Basically, the change of natural frequencies of the structure can be used as the indicator of the damage occurrence but not as the indicator of the damage location as the natural frequency changes does not carry the geometric information of the structure. In this research, the feedback scope method that measures the natural frequency changes of the structure with and without the feedback Ioo...

  • PDF

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

  • Park, J.H.
    • Journal of Power System Engineering
    • /
    • v.7 no.4
    • /
    • pp.38-43
    • /
    • 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.

  • PDF

An Equalization Technique of Dual-Feedback Structure in ATSC DTV Receivers (ATSC DTV 수신기를 위한 이중 후방필터 구조의 결정 궤환 등화기)

  • Oh, Young-Ho;Kim, Dae-Jin
    • Journal of Broadcast Engineering
    • /
    • v.10 no.4 s.29
    • /
    • pp.540-547
    • /
    • 2005
  • In the DFE(Decision Feedback Equalizer) for ATSC DTV receivers, there are decision errors in the slicer or. the simplified trellis decoder, and these decided false data comes to the feedback filter to make the error propagation phenomenon. The error propagation degrades the equalizer performance by increasing residual errors as well as slowing down the convergence rate. In this paper we propose a dual-feedback equalization structure. There are two feedback filters. One is the decision feedback filter which uses the simplified trellis decoder output data, the other is non-decision feedback filter which uses the equalizer output data. The additional non-decision feedback filter doesn't introduce the error propagation, so it can compensate the error propagation. The proposed structure accelerates the convergence rate as well as reduces output men-square error(MSE). We analyzed the performance enhancement of DTV receiver using dual-feedback equalization structure.

An Analysis of the Dynamics of the Capitalism's Evolution with Systems Thinking (시스템사고를 통한 자본주의 진화과정의 동태성 분석)

  • Choi, Nam-Hee
    • Korean System Dynamics Review
    • /
    • v.15 no.4
    • /
    • pp.101-127
    • /
    • 2014
  • This study aims to understand how and why each stage of capitalism grows and changes into the new direction in the moment of crisis, based on the systems thinking approach through the causal loop feedback structure. To achieve the research purpose, it classifies the evolution process of the capitalistic economic system into 4 types: Capitalism 1.0(Classical Laissez-Faire Capitalism), 2.0(Revised Capitalism), 3.0(Neo-liberalism), and 4.0(New Capitalism for the Future). This study focuses particularly on by which feedback structure the growth, crisis, and new transition of capitalism could be explained. The main research results are as follows. The intended positive feedback structure caused the growth at each early stage of capitalism. After that time, as a result of the uncontrolled growth, the negative feedback structure controlling its growth operated on the one hand, while the positive feedback structure amplifying the crisis did on the other hand. The study suggests the Resilient Capitalism as the new evolutional direction of Capitalism 4.0. It can contribute to strengthening its resilience by which all the economic players can recover promptly and flexibly from the crises such as the failure of competition and unemployment.

  • PDF

A New Robust Discrete Static Output Feedback Variable Structure Controller with Disturbance Observer for Uncertain Discrete Systems (불확실 이산 시스템을 위한 외란관측기를 갖는 새로운 둔감한 이산 정적 출력 궤환 가변구조제어기)

  • Lee, Jung-Hoon
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.59 no.3
    • /
    • pp.630-635
    • /
    • 2010
  • In this paper, a new discrete static output feedback variable structure controller based on a new dynamic-type sliding surface and output feedback discrete version of the disturbance observer is suggested for the control of uncertain linear systems. The reaching phase is completely removed by introducing a new proposed dynamic-type sliding surface. The output feedback discrete version of disturbance observer is derived for effective compensation of uncertainties and disturbance. A corresponding control with disturbance compensation is selected to guarantee the quasi sliding mode on the predetermined dynamic-type sliding surface for guaranteeing the designed output in the dynamic-type sliding surface from any initial condition for all the parameter variations and disturbances. Using Lyapunov function, the closed loop stability and the existence condition of the quasi sliding mode is proved. Finally, an illustrative example is presented to show the effectiveness of the algorithm.

Robust Controllers for Large Space Structures Using an SPR Filter and Displacement Feedback (변위ㆍ정보와 SPR 필터를 이용한 대형 우주 구조물의 강인 제어기에 관한 연구)

  • 손영익;심형보;조남훈
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.52 no.9
    • /
    • pp.520-525
    • /
    • 2003
  • A robust controller for large space structures(LSS) is studied from passivity point of view. While velocity sensors are commonly used for proportional-derivative (PD) control law to stabilize large space structures, if the structure can be controlled without velocity measurements, it is desirable against the failure of velocity sensors and for the cost reduction of the sensing system. In a recent result a dynamic output feedback control law has been provided using only displacement measurements. This paper presents a passivity-based controller design method and provides an alternative stability analysis tool for the previous displacement feedback robust control law. The closed-loop system can be viewed as a feedback interconnection of a passivated large space structure (LSS) and a strictly positive real (SPR) system.

Strategic Diagnosis on the Dynamics of the Regional Technology Commercialization Ecosystem (기술사업화 생태계의 동태성에 대한 전략적 진단)

  • Choi, Nam-Hee
    • Korean System Dynamics Review
    • /
    • v.17 no.3
    • /
    • pp.145-173
    • /
    • 2016
  • This study aims to develop strategic diagnosis framework of performance by identifying and analysing the dynamics of the technology commercialization ecosystem in innovative region. To achieve the purpose of this study, the systems thinking approach is used. The systems thinking approach connects feedback structure and behavior more explicitly to diagnosis vicious feedback loop in the regional technology commercialization ecosystem. In terms of an ecological point of view, it will be possible to explore dominant feedback structure and find leverages to overcome the limitations of regional technology commercialization performance. The diagnosis of reenforcing and balancing feedback structure is based on the statistical analysis of the survey data which has been collected in a cluster random sampling method, targeting on the 200 firm located in the Pangyo and Daeduk region. The results from this research showed that the regional technology commercialization ecosystem was immature and faced limit to the growth. An important finding of this study was that regional technology commercialization ecosystem need to activation of startups and reinforcement of virtuous feedback structures of technology commercialization market systems.