• Title/Summary/Keyword: reduced-order controller

Search Result 235, Processing Time 0.021 seconds

Lead-Lag Controller Design of Direct Drive Servo Valve Using Complex Method (컴플렉스법에 의한 직접구동형서보밸브의 진상-지상 제어기 설계)

  • Lee, Seong-Rae
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.28 no.11
    • /
    • pp.1719-1726
    • /
    • 2004
  • Direct drive servovalve(DDV) is a kind of one-stage valve because the main spool valve is directly driven by the DC motor. Since the structure of DDV is simple, it is less expensive, more reliable and offers reduced internal leakage and reduced sensitivity to fluid contamination. However, the flow force effect on the spool motion is significant such that it induces large steady-state error in a step response. If the proportional control gain is increased to reduce the steady-state error, the system becomes unstable. In order to satisfy the system design requirements, the lead-lag controller is designed using the complex method that is one kind of constrained direct search method.

Classical Controller Design of Direct Drive Servo Valve Using Analytical Bode Method (해석적 Bode 방법에 의한 직접구동형서보밸브의 고전적 제어기 설계)

  • Lee, Seong-Rae;Choe, Hyeon-Yeong;Mun, Ui-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.26 no.4
    • /
    • pp.754-763
    • /
    • 2002
  • Direct drive servovalve(DDV) is a kind of one-stage valve since the rotary motion of DC motor is directly transferred to the linear motion of valve spool through the link. Since the structure of DDV is simple, it is less expensive, more reliable and offers reduced internal leakage and reduced sensitivity to fluid contamination. However, the flow force effect on the spool motion is significant such that it induces large steady-state error in a step response. If the proportional control gain is increased to reduce the steady-state error, the system becomes unstable. In order to satisfy the system design requirements, the classical controller is designed using the analytical Bode method.

The Control of Single Phase Power Factor PWM converter using Reduced-Order Luenberger Observer (축소차원 Luenberger 관측기를 이용한 단산 PWM 컨버터의 고역률 제어)

  • 양이우;이용근;김영석
    • Proceedings of the KIPE Conference
    • /
    • 1999.07a
    • /
    • pp.485-488
    • /
    • 1999
  • In this paper, a current control system for single phase PWM AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimation of source voltage is performed by the reduced-order Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by experiments.

  • PDF

The Control of Single Phase High Power Factor PWM converter using Reduced-order Luenberger Observer (축소차원 Luenberger 관측기를 이용한 단상 PWM 컨버터의 고역율 제어)

  • 양이우;유지용;김영석
    • Proceedings of the KIPE Conference
    • /
    • 1998.11a
    • /
    • pp.78-82
    • /
    • 1998
  • In this paper, the authors propose a current control system of single phase PWM AC/DC converter without the source voltage sensors. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimations of source voltage are performed based on the reduced-order Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by simulations

  • PDF

Robust controller design for RTP system using structured uncertainty approach (구조적 불확실성 접근을 이용한 RTP 시스템의 견실제어기 설계)

  • Lee, Sang-Kyung;Kim, Jong-Hae;Kim, Hae-Kun;Park, Hong-Bae
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.5 no.6
    • /
    • pp.667-675
    • /
    • 1999
  • In this paper, we propose a robust controller design of RTP(Rapid Thermal Processing) system using structured uncertainty approach. Using the weighted mixed sensitivity function, we solve the robust stability problem against disturbance and temperature variation, and design a $\mu$ controller using curve fitting method against structured uncertainty. Also the reduction method should be requried because of the difficulty of implementaion with the obtained high order controller. We dal with robust stability and performance of RTP system by the design of $\mu$ controller for original model and Schur balanced reduced model. Finally the simulation results are proposed to show the validity of the proposed method.

  • PDF

Linear Motor Current Control for a Force Generator (운동용 힘 발생기를 위한 리니어 모터의 전류제어)

  • Lee, Se-Han
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.18 no.1
    • /
    • pp.1-9
    • /
    • 2015
  • This research dealt with a two-degree-of-freedom controller which was used for 2-dimensional force generator based on an linear motor. The gain margin of the controller may be reduced when the time constant is near to the sampling time of a discrete controller. In case of low gain controller, it cannot satisfy the control performance. A two-degree-of-freedom controller based on PI-control was proposed. It can manage performance and stability respectively. It also had a kind of a feed-forward control. This scheme can not only lessen gain of conventional PI controller in order to stability but also obtain high tracking performance.

LMI-based $H_{\infty}$ Controller Design for a Line of Sight Stabilization System

  • Lee, Won-Gu;Keh, Joong-Eup;Kim, In-Soo;Lee, Man-Hyung
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.497-497
    • /
    • 2000
  • This paper is concerned with the design of LMI based H$_{\infty}$ controller for a line of sight(LOS) stabilization system. This system which is even linearized to analyse nonlinear characteristic has also a lot of uncertainties. In addition, the angular velocity disturbance from the vehicle's driving deteriorates the stabilized LOS, main purpose of this system. In case of fast driving, particularly, all components which are ignored and skipped to make mathematical modelling act as the uncertainties against this system. The robustness against these uncertainties has been also continuously demanded including the well tracking performance for the target. Therefore, this paper employed H$_{\infty}$ control theory to satisfy these problems and LMI method to make suitable controller with few constraints for this system. Although this system matrix doesn't have full rank, this method make it possible to design H$_{\infty}$ controller and deal with R and S matrices for reducing its order. Consequently, this paper shows that the re-analyses on the real disturbances are achieved and the proposed robust controller for them has better disturbance attenuation and tracking performance. This paper contributes the applicability of reduced order H$_{\infty}$ controller to real system by handling LMI..

  • PDF

The Design of Variable Structure Controller for the System in Phase Canonical Form with Incomplete State Measurements (비 측정 상태변수를 갖는 위상 표준형계통에 대한 가변구조 제어기의 설계)

  • 박귀태;최중경
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.41 no.8
    • /
    • pp.902-913
    • /
    • 1992
  • There have been several control schemes for the single input systems with unmeasurable state variables using variable structure control(VSC) theory. In the previous VSC, the systems must be represented in phase canonical form and the complete measurements for each state variable must be assumed. In order to eliminate these restrictions several VSC methods were proposed. And especially for the systems in phase canonical form with unmeasurable state variables, the reduced order switching function algorithm was proposed. But this method has many drawbacks and can not be used in the case of general form (not phase canonical form) dynamic system. Therefore this paper propose new construction method of switching fuction for the systems in phase canonical form, which reduce the restriction of reduced order switching function algorithm. And this algorithm can be realized for any state representation and adopted in the systems where not all states are available for switching function synthesis or control.

  • PDF

Reduced variance implicit self-tuning a;gorithm with variable time-delays for robot manipulator (로보트 매니풀레이터의 시변 지연 시간을 고려한 분산 감소 임플리시트 자기동조 알고리즘)

  • 이희진;박민용;이상배
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1988.10a
    • /
    • pp.12-15
    • /
    • 1988
  • A controller described in this paper is designed for implicit generalised minimum varience controller with variable time delays in which the weighting polynominals are calculated to reduce the output and control signals variances. This paper is based on the fact that the pole-assigment equation may have multiple solutions if the weighting polynominals are not of minimal order. It is shown that the larger order of the weighting polynominals increment the better is the stochastic behavior of the closed-loop system with variable time delays without changs in the deterministic behavior of the system. Based on this theory, the controller is applied to position control of a three-link manipulater with parameter uncertainty.

  • PDF

An anti-filtering compensator design for a stable implementation of time delay controller (시간지연제어기를 안정하게 구현하기 위한 대향 필터링 보상기의 설계)

  • 문의준;이상열;이영철;이정훈
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1992.10a
    • /
    • pp.1034-1039
    • /
    • 1992
  • Time Delay Controller(TDC) is a model following controller which uses input and output values and state variables to estimate additional quantity of dynamics due to external disturbances and/or model parameters variation at some past instant. TDC is very robust against parametric uncertainty whil it is not robust against unmodeled dynamics even showing instability. To solve this problem a stability anlysis is performed and a compensation technique using reduced order observer, Anti-Filtering Compensator(AFC), is proposed for a case in which the high order kinown dynamics is deliberately ignored. If the ignored dynamics causes instability of the TDC control system, AFC is shown to be indispensible fot a stable implementation of TDC.

  • PDF