• Title, Summary, Keyword: robust $H_{\infty}$ control

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Robust $H_{\infty}$ Controller Design for Steam Generator Water Level Control using Mixed $H_{\infty}$ Optimization Method (혼합 $H_{\infty}$ 최적화 기법을 이용한 견실 $H_{\infty}$ 증기발생기 수위제어기 설계)

  • 서성환;조희수;박홍배
    • Journal of Institute of Control, Robotics and Systems
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    • v.5 no.3
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    • pp.363-369
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    • 1999
  • In this paper, we design the robust $H_{\infty}$ controller for water level control of steam generator using a mixed $H_{\infty}$ optimization with model-matching method. Firstly we choose the desired model which has good disturbance rejection performance. Secondly we design a stabilizing controller to keep the model-matching error small and also provide sufficiently large stability margin against additive perturbations of the nominal plant. Simulation results show that proposed robust $H_{\infty}$ controller at specific power operation has satisfactory performances against the variations of load power, steam flow rate, primary circuit coolant temperature, and feedwater temperature. It can be also observed that the proposed robust $H_{\infty}$ controller exhibits better robust stability than conventional PI controller.

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Robust $H_{\infty}$ Control for Bilinear Systems with Parameter Uncertainties via output Feedback

  • Kim, Young-Joong;Lee, Su-Gu;Chang, Sae-Kwon;Kim, Beom-Soo;Lim, Myo-Taeg
    • 제어로봇시스템학회:학술대회논문집
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    • pp.386-391
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    • 2003
  • This paper focuses on robust $H_{\infty}$ control for bilinear systems with time-varying parameter uncertainties and exogenous disturbance via output feedback. $H_{\infty}$ control is achieved via separation into a $H_{\infty}$ state feedback control problem and a $H_{\infty}$ state estimation problem. The suitable robust stabilizing output feedback control law can be constructed in term of approximated solution to x-dependent Riccati equation using successive approximation technique. Also, the $H_{\infty}$ filter gain can be constructed in term of solution to algebraic Riccati equation. The output feedback control robustly stabilizes the plant and guarantees a robust $H_{\infty}$ performance for the closed-loop systems in the face of parameter uncertainties and exogenous disturbance.

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Robust Depth and Course Control of AUV Using LMI-based $H_{\infty}$ Servo Control (LMI에 기초한 $H_{\infty}$ 서보제어를 이용한 AUV의 강인한 자동 심도 및 방향제어)

  • 양승윤;김인수;이만형
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.1
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    • pp.38-46
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    • 2000
  • In this paper, robust depth and course controllers of AUV(autonomous underwater vehicles) using LMI-based H$_{\infty}$ servo control are proposed. The $H_{\infty}$ servo problem is modified to an $H_{\infty}$ control problem for the generalized plant that includes a reference input mode, and then a sub-optimal solution that satisfies a given performance criteria is calculated by LMI(Linear Matrix Inequality) approach. The robust depth and course controllers are designed to be satisfied the robust stability about the modeling error generated from the perturbation of the hydrodynamic coefficients and the robust tracking property under sea wave and tide disturbances. The performances of the designed controllers are evaluated by computer simulations, and these simulation results show the applicability of the proposed robust depth and course controller.

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Parallel Robust $H_{\infty}$ Control for Weakly Coupled Bilinear Systems with Parameter Uncertainties Using Successive Galerkin Approximation

  • Kim, Young-Joong;Lim, Myo-Taeg
    • International Journal of Control, Automation, and Systems
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    • v.4 no.6
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    • pp.689-696
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    • 2006
  • This paper presents a new algorithm for the closed-loop $H_{\infty}$ composite control of weakly coupled bilinear systems with time-varying parameter uncertainties and exogenous disturbance using the successive Galerkin approximation(SGA). By using weak coupling theory, the robust $H_{\infty}$ control can be obtained from two reduced-order robust $H_{\infty}$ control problems in parallel. The $H_{\infty}$ control theory guarantees robust closed-loop performance but the resulting problem is difficult to solve for uncertain bilinear systems. In order to overcome the difficulties inherent in the $H_{\infty}$ control problem, two $H_{\infty}$ control laws are constructed in terms of the approximated solution to two independent Hamilton-Jacobi-Isaac equations using the SGA method. One of the purposes of this paper is to design a closed-loop parallel robust $H_{\infty}$ control law for the weakly coupled bilinear systems with parameter uncertainties using the SGA method. The other is to reduce the computational complexity when the SGA method is applied to the high order systems.

Damping of Low Frequency Oscillation in Power System using Robust Control of Superconductor Flywheel Energy Storage System (초전도 플라이휠 에너지 저장장치의 강인제어를 이용한 전력계통의 저주파진동 억제)

  • Lee, J.P.;Kim, H.G.
    • Progress in Superconductivity
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    • v.14 no.1
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    • pp.52-59
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    • 2012
  • In this paper, the robust superconductor flywheel energy storage system(SFESS) controller using $H_{\infty}$ control theory was designed to damp low frequency oscillation of power system. The main advantage of the $H_{\infty}$ controller is that uncertainties of power system can be included at the stage of controller design. Both disturbance attenuation and robust stability for the power system were treated simultaneously by using mixed sensitivity $H_{\infty}$ problem. The robust stability and the performance for uncertainties of power system were represented by frequency weighted transfer function. To verify control performance of proposed SFESS controller using $H_{\infty}$ control, the closed loop eigenvalue and the damping ratio in dominant oscillation mode of power system were analyzed and nonlinear simulation for one-machine infinite bus system was performed under disturbance for various operating conditions. The results showed that the proposed $H_{\infty}$ SFESS controller was more robust than conventional power system stabilizer (PSS).

A Design on Model-Following $H_{\infty}$ Control System Having Robust Performance (강인한 성능을 가지는 모델추종형 $H_{\infty}$ 제어 시스템의 설계)

  • Hwang, Hyun-Joon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.5
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    • pp.913-921
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    • 2009
  • This paper suggests a deign method of the model-following $H{\infty}$ control system having robust performance. This $H{\infty}$ control system is designed by applying genetic algorithm(GA) with reference model to the optimal determination of weighting functions and design parameter ${\gamma}$ that are given by $H{\infty}$ control theory. These weighting functions and design parameter ${\gamma}$ are optimized simultaneously in the search domain guaranteeing the robust performance of closed-loop system. The effectiveness of this $H_{\infty}$ control system is verified by computer simulation.

Robust H$_{\infty}$ Control Method for Bilinear Systems

  • Kim, Beom-Soo;Lim, Myo-Taeg
    • International Journal of Control, Automation, and Systems
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    • v.1 no.2
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    • pp.171-177
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    • 2003
  • In this paper, we investigate a robust $H_{\infty}$ state feedback control technique for continuous time bilinear systems with an additive disturbance input. The nonlinear robust $H_{\infty}$control for bilinear systems requires a solution to the state dependent algebraic Riccati equation (SDARE). We present a new robust $H_{\infty}$control technique based on the successive approximation method for solving the SDARE by converting bilinear systems into time-varying linear systems. The proposed control method guarantees robust stability for closed loop bilinear systems. The proposed algorithm is verified by numerical examples.

$H^{\infty}$ robust adaptive controller design with parameter uncertainty, unmodeled dynamic and bounded noise (파라미터 불확실성,모델 불확실성,한계 잡음에 대한 $H^{\infty}$ 적응제어기 설계)

  • Baek, Nam-Seok;Yang, Won-Young
    • Proceedings of the KIEE Conference
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    • pp.454-456
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    • 1998
  • Traditional adaptive control algorithms are not robust to dynamic uncertainties. The adaptive control algorithms developed previously to deal with dynamic uncertainties do not facilitate quantitative design. We proposed a new robust adaptive control algorithms consists of an $H^{\infty}$ suboptimal control law and a robust parameter estimator. Numerical examples showing the effectiveness of the $H^{\infty}$ adaptive scheme are provided.

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Robust $H_{\infty}$ Controller Design for Performance Improvement of Semi-Active Suspension System (반능동 현가장치의 성능향상을 위한 견실 $H_{\infty}$ 제어기 설계)

  • 정승권
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.9 no.4
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    • pp.85-90
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    • 2000
  • In this paper, a robust $H_{\infty}$ a controller for semi-active suspension system is proposed. For the improvement of ride quality, the robust $H_{\infty}$ controller is designed to satisfy robust stability and road disturbance attenuation using an $H_{\infty}$ control design procedure. The performances of the design controller for some road conditions are evaluated by computer simulation and finally these simulation results show the usefulness and applicability of the proposed robust $H_{\infty}$ controller.

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