• Title, Summary, Keyword: $H_\infty$

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The LMI mixed ${H_2}/H_{\infty}$ control of inverted pendulum system using LFR (도립진자 시스템의 LFR에 의한 LMI 혼합 ${H_2}/H_{\infty}$ 제어)

  • 박종우;이상철;이상효
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.7A
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    • pp.967-977
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    • 2000
  • In this paper, we apply a mixed $H_2/H_{\infty}$ control to a generalized plant of inverted pendulum system represented by an LFR(Linear Fractional Representation). First, in order to obtain the generalized plant, the linear model of the inverted pendulum represented by an LFR(Linear fractional Representation) is derived. In LFR, we consider system uncertainties as three nonlinear components and a pendulum mass uncertainty. Augmenting the LFR model by adding weighting functions, we get a generalized plant. And then, we design a mixed $H_2/H_{\infty}$ controller for the generalized plant. In order to design the mixed $H_2/H_{\infty}$ controller, we use the LMI technique. To evaluate control performances and robust stability of the mixed $H_2/H_{\infty}$ controller designed, we compare it with the $H_{\infty}$ controller through the simulation and experiment. In the result, with the fewer feedback information, the mixed $H_2/H_{\infty}$ controller shows the better control performances and robust stability than the $H_{\infty}$ controller in the sense of pendulum angle.

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Design of an LMI- Based H^{\infty} Servo Controller for Tandem Cold Mill (LMI 에 기초한 연속 냉간압연기의 H^{\infty} 서보 제어기 설계)

  • Kim, In-Soo;Hwang, I-Cheol;Lee, Man-Hyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.1
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    • pp.25-34
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    • 2000
  • In this paper, we design a H^\infty servo controller for gauge control of tandem cold mill. To improve the performance of the AGC(Aotomatic Gauge Control) system based on the Taylor linearized model of tandem cold mill, the H^\infty servo controller is designed to satisfy robust stability, disturbance attenuation and robust tracking properties. The H^\infty servo controller problem is modified as an usual H^\infty control problem, and the solvability condition of the H^\infty servo problem depends on the solvability of the modified H^\infty control problem. Since this modified problem does not satisfied standard assumptions for the H^\infty control problem, it is solved by an LMI(Linear Matrix Inequality) technique. Consequently, the comparison between the H^\infty servo controller and the existing PID/FF(FeedForward) controller shows the usefulness of this study.

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Mixed $H_2/H_{\infty}$ Controller Realization with Entropy Integral

  • Lee, Sang-Hyuk;Kim, Ju-Sik
    • International Journal of Control, Automation, and Systems
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    • v.1 no.2
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    • pp.206-209
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    • 2003
  • An $H_2$/$H_{\infty}$ -controller realization is carried out by considering an entropy integral. Using J-spectral factorization, the parametrizations of all $H_{\infty}$ stabilizing controllers are derived. By the relation of a mixed $H_2$/$H_{\infty}$ control problem and a minimum entropy/$H_{\infty}$ control problem, the mixed $H_2$/$H_{\infty}$-controller state-space realization is presented.

A mixed $H_2/ H_\infty$ digital control of Inverted pendulum system (도립진자 시스템의 혼합$H_2/ H_\infty$ 디지털 제어)

  • 박종우;곽칠성
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.5
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    • pp.1111-1116
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    • 2000
  • The mixed $H_2/ H_\infty$ control method is one of positive approaches to design a controller having both the$H_2$-performance and the $H_\infty$-robust stability. In this paper, Firstly, The tracking Performance to be designed has been represented as $H_2$-norms for the plants with uncertainties. Secondly, $H_\infty$-norm have been set up in order to ensure the robust stabilities. The mixed digital controllers have been designed for an inverted system. The mixed $H_2/ H_\infty$digital controller for the inverted pendulum system was intended to stabilize the unstability of the plant together with the good tracking Performance.

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The $H_2/ H_\infty$ control of inverted pendulum system using linear fractional representation (도립진자 시스템에 선형 분수 표현법을 이용한 $H_2/ H_\infty$ 제어)

  • 곽칠성;최규열
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.3 no.4
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    • pp.875-885
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    • 1999
  • This paper presents an application of LMI-based techniques to the mixed $H_2/ H_\infty$ control of an inverted pendulum. The linear model of the inverted pendulum represented by an LFR(Linear Fractional Representation) model of uncertainties is derived. Considered uncertainties are three nonlinear components and a parameter uncertainty Augmenting the LFR model by adding weighting functions, we get a generalized plant, for which we design a mixed $H_2/ H_\infty$ controller using the LMI technique. To evaluate control performances and robust stability of the mixed $H_2/ H_\infty$ controller designed, we compare it with the $ H_\infty$controller through the simulation and experiment. The mixed $H_2/ H_\infty$ controller shows the better control performances and robust stability than the $H_\infty$controller in the sense of pendulum angle.

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$H_\infty$ Depth Controller Design for Underwater Vehicles (수중운동체의 $H_\infty$ 심도제어기 설계)

  • 이만형;정금영;김인수;주효남;양승윤
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.5
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    • pp.345-355
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    • 2000
  • In this paper, the depth controller of an underwater vehicle based on an $H_\infty$ servo control is designed for the depth keeping of the underwater vehicle under wave disturbances. The depth controller is designed in the form of the $H_\infty$ servo controller, which has robust tracking property, and an $H_\infty$ servo problem is considered for the $H_\infty$ servo controller design. In order to solve the $H_\infty$ servo problem for the underwater vehicle, this problem is modified as an $H_\infty$ control problem for the generalized plant that includes a reference input mode, and a suboptimal solution that satisfies a given performance criteria is calculated with the LMI (Linear Matrix Inequality) approach. The $H_\infty$ servo controller is designed to have robust stability about the perturbation of the parameters of the underwater vehicle and the robust tracking property of the underwater vehicle depth under wave force and moment disturbances. The performance, robustness about the uncertainties, and depth tracking property, of the designed depth controller is evaluated by computer simulation, and finally these simulation results show the usefulness and applicability of the proposed $H_\infty$ depth control system.

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$H_{2}$/$H_{\infty}$ control of active suspension system (능동 현가 시스템을 위한 $H_{2}$/$H_{\infty}$ 제어기 설계)

  • 정우영;김상우;원상철
    • 제어로봇시스템학회:학술대회논문집
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    • pp.888-891
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    • 1996
  • The objective of a mixed H$_{2}$/H$_{\infty}$ controller of active suspension system is to achieve not only the general performance improvement(H$_{2}$) but also the worst case disturbance rejection(H$_{\infty}$). In this paper, a mixed H$_{2}$/H$_{\infty}$ controller for an active suspension system, comparing the performance with that of an H$_{2}$ controller and of an H$_{\infty}$ controller.ler.EX> controller.

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Fuzzy H2/H Controller Design for Delayed Nonlinear Systems with Saturating Input (포화입력을 가지는 시간지연 비선형 시스템의 퍼지 H2/H 제어기 설계)

  • Cho, Hee-Soo;Lee, Kap-Rai;Park, Hong-Bae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.3
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    • pp.239-245
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    • 2002
  • In this Paper, we present a method for designing fuzzy $H_2/H_{\infty}$ controllers of delayed nonlinear systems with saturating input. Takagi-Sugeno fuzzy model is employed to represent delayed nonlinear systems with saturating input. The fuzzy control systems utilize the concept of the so-called parallel distributed compensation(PDC). Using a single quadratic Lyapunov function, the globally exponential stability and $H_2/H_{\infty}$ performance problem are discussed. And a sufficient condition for the existence of fuzzy $H_2/H_{\infty}$ controllers is given in terms of linear matrix inequalities(LMIs). The designing fuzzy $H_2/H_{\infty}$ controllers minimize an upper bound on a linear quadratic performance measure. Finally, a design example of fuzzy $H_2/H_{\infty}$ controller for uncertain delayed nonlinear systems with saturating input.

$H_{\infty}$ Depth and Course Controllers Design for Autonomous Underwater Vehicles (무인 수중운동체의 $H_{\infty}$ 심도 및 방향 제어기 설계)

  • Yang, Seung-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.12
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    • pp.2980-2988
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    • 2000
  • In this paper, H(sub)$\infty$ depth and course controllers of autonomous underwater vehicles using H(sub)$\infty$ servo control are proposed. An H(sub)$\infty$ servo problem is foumulated to design the controllers satisfying a robust tracking property with modeling errors and disturbances. The solution of the H(sub)$\infty$servo problem is as follows; firest, this problem is modified as an H(sub)$\infty$ control problem for the generalized plant that includes a reference input mode, and than a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach, The H(sub)$\infty$depth and course controllers are designed to satisfy the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under disturbances(was force, wave moment, tide). The performances(the robustness to the uncertainties, depth and course tracking properties) of the designed controlled are evaluated with computer simulations, and finally these simulation results show the usefulness and applicability of the propose H(sub)$\infty$ depth and course control systems.

Congestion Control in ATM Networks using an $H_{\infty}$ Filter ($H_{\infty}$ 필터를 이용한 초고속 비동기전송망의 체증 제어)

  • Lee, Su-Gu;Kim, Young-Jung;Kim, Beom-Soo;Lim, Myo-Taeg
    • Proceedings of the KIEE Conference
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    • pp.2137-2139
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    • 2003
  • 본 논문에서는 초고속 비동기전송(ATM)망에서의 체증 문제를 풀기위해 $H_{\infty}$ 필터 사용을 제안한다. 많은 제어기들에 대한 초기 연구들은 가용 비트율이 망 체증이 제거될 수 있도록 버퍼에서의 원하는 셀들의 큐의 길이를 원하는 값 범위내에서 성공적으로 조절될 수 있음을 보이고 있다. 본 논문에서는 망의 노이즈를 가우시안 랜덤 열로 근사화하는 ATM망에 대하여 현대 제어 기법인 $H_{\infty}$ 필터를 적용한다. 따라서 제안한 $H_{\infty}$ 필터는 망의 외란으로 밭생하는 망의 출력의 영향을 미리 주어지는 $H_{\infty}$ 노옴값 이내로 유지시켜준다. 따라서 미리 주어지는 $H_{\infty}$ 노옴값이 작다면 제안한 $H_{\infty}$ 필터는 외란에 강인한 성능을 보여줄 수 있다. $H_{\infty}$ 필터 이득은 대수적인 리카티 방정식의 해로 구해진다.

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