• Title/Summary/Keyword: Feedback Control System

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Feedback Linearization for the Looper System of Hot Strip Mills

  • Hwang, I-Cheol;Kim, Seong-Bae
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.56.5-56
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    • 2002
  • This paper studies on the feedback linearization of the looper system for hot strip mills, where the looper system plays an important role in regulating the strip tension. Firstly, nonlinear dynamic equations of the looper system are simply introduced. Secondly, using the static feedback linearization algorithm, a linear model of the looper system is obtained, of which usefulness is validated from comparison between the linear model and the nonlinear model, and design of LQI(Linear Ouadratic Integral optimal control) and ILQ (Inverse Linear Quadratic optimal control) looper control systems. In result, it is shown that the linear looper model by the feedback linearization well describes nonlin...

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Robust Stability Condition and Analysis on Steady-State Tracking Errors of Repetitive Control Systems

  • Doh, Tae-Yong;Ryoo, Jung-Rae
    • International Journal of Control, Automation, and Systems
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    • v.6 no.6
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    • pp.960-967
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    • 2008
  • This paper shows that design of a robustly stable repetitive control system is equivalent to that of a feedback control system for an uncertain linear time-invariant system satisfying the well-known robust performance condition. Once a feedback controller is designed to satisfy the robust performance condition, the feedback controller and the repetitive controller using the performance weighting function robustly stabilizes the repetitive control system. It is also shown that we can obtain a steady-state tracking error described in a simple form without time-delay element if the robust stability condition is satisfied for the repetitive control system. Moreover, using this result, a sufficient condition is provided, which ensures that the least upper bound of the steady-state tracking error generated by the repetitive control system is less than or equal to the least upper bound of the steady-state tracking error only by the feedback system.

Dynamic Output Feedback Passivation of Nonlinear Systems with Application to Flexible Joint Robots (비선형 시스템의 동적 출력 궤환 수동화의 유연 관절 로봇에의 적용)

  • Son Young-Ik;Lim Seungchul;Kim Kab-Il
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.12
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    • pp.1256-1263
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    • 2004
  • Output feedback passivation problem is studied when the given system is not minimum-phase or does not have relative degree one. Using a parallel connection with an additional dynamics, the authors provide a dynamic output feedback control law which renders the composite system passive. Sufficient conditions are presented under which the composite system is output feedback passive. As an application of the dynamic passivation scheme, a point-to-point control law for a flexible joint robot is presented when only the position measurements are available. This provides an alternative way of replacing the role of the velocity measurements for the proportional-derivative (PD) feedback law. The performance of the proposed control law is illustrated in the simulation studies of a manipulator with three revolute elastic joints.

A Differential Supervisory Controller for Robustness Increase of Feedback Control System (궤환 제어시스템의 강인성 증진을 위한 미분 관리제어기)

  • 박왈서
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.8
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    • pp.363-367
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    • 2003
  • Robust control for feedback control system is needed according to the highest precision of industrial automation. However, when a feedback control system has an effect of disturbance, it is very difficult to guarantee the robustness of control system. As a compensation method solving this problem, in this paper, Hybrid control method of feedback and Differential Supervisory controller is presented. A Feedback Controller is operated as a main controller, A Differential Supervisory Controller is a controller which operates only when some undesirable phenomena occur, e. g., when the error hits the boundary of constraint set. The robust control function of Differential Supervisory Controller, as a assistant controller is operated when state is unstable by disturbance. it demonstrated by speed control of motor.

Seismic test of modal control with direct output feedback for building structures

  • Lu, Lyan-Ywan
    • Structural Engineering and Mechanics
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    • v.12 no.6
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    • pp.633-656
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    • 2001
  • In this paper, modal control with direct output feedback is formulated in a systematic manner for easy implementation. Its application to the seismic protection of structural systems is verified by a shaking table test, which involves a full-scale building model and an active bracing system as the control device. Two modal control cases, namely, one full-state feedback and one direct output feedback control were tested and compared. The experimental result shows that in mitigating the seismic response of building structures, modal control with direct output feedback can be as effective and efficient as that with full-state feedback control. For practical concerns, the control performance of the proposed method in the presence of sensor noise and stiffness modeling error was also investigated. The numerical result shows that although the control force may be increased, the maximum floor displacements of the controlled structure are very insensitive to sensor noise and modeling error.

Hybrid PD-Servo State Feedback Control Algorithm for Swing up Inverted Pendulum System

  • Nundrakwang, Songmoung;Benjanarasuth, Taworn;Ngamwiwit, Jongkol;Komine, Noriyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.690-693
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    • 2005
  • In this paper, a hybrid PD-servo state feedback control algorithm for swing up inverted pendulum system is proposed. It consists of two parts. The first part is the PD position control for swinging up the pendulum from the natural pendent position to around the upright position and the second part is the servo state feedback control for stabilizing the inverted pendulum in upright position. The first controller is PD controller and it is tuned to control the position of the pendulum by moving the cart back and forth until the pendulum swings up around the upright position. Then the second controller will be switched to stabilize the inverted pendulum in its upright position. The controller in this stage is the servo state feedback controller designed by pole placement. Experimental results of PD type swinging up control system, of stabilizing servo state feedback control system and of the proposed hybrid PD-servo state feedback control system to swing up and stabilize inverted pendulum show that the proposed method is effective and reliable for actual implementation while it is simple.

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Properties of ATMD with Acceleration Feedback System (가속도귀환방식에 의한 ATMD의 특성)

  • 최민호;강병두;노필성;김재웅
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.242-249
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    • 1995
  • In order to search more efficient structural control algorithm, several closed-loop algorithm are developed. Among those, feedback control algorithm using parameters as displacement velocity, and acceleration has been studied. In this paper, especially the characteristics of accleration feedback is studied as more efficient control algorithm than any others. Furthermore the fact that ATMD with acceleration feedback system further reduce the variance of structural displacement rather than with displacement or velocity feedback system will be examined and proved.

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Feedback Control of a Circular Cylinder Wake with Rotational Oscillation (주기적 회전을 이용한 원봉 후류의 되먹임 제어)

  • Lee S. B.;Baek S.-J.;Sung H. J.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.51-56
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    • 2005
  • A new feedback control system based on system identification is proposed and preliminarily tested on Van der Pol equation which has a similar characteristic to circular cylinder. The same principle is applicable to circular cylinder in a uniform flow for suppresing the vortex shedding. The feedback controller is designed to impose feedback signal at the phase which is located outside the range of lock-on. The lift coefficient (CL) is employed as a feedback signal and the control forcing is given by a rotational oscillation of the cylinder. By applying the feedback control system, the lift coefficient is reduced.

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Design of the Inverter Control System of Punching M/C (Punching M/C의 인버터 제어기 설계)

  • Cho, Hyeon-Seob;Jun, Ho-Ik
    • Proceedings of the KAIS Fall Conference
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    • 2010.05a
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    • pp.132-134
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    • 2010
  • In this paper new, inverter control system for TG feedback a formula Control was developed. The motor control system with TG feedback controller as an effect of load disturbance, it is very difficult to guarantee the robustness of control system. The function of the implementation are TG feedback type, and temperature scheme. The Inverter Control System approach is based on master-slave control concept. To show validity of the developed new inverter control system, severial experiments are illustrated.

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