• Title/Summary/Keyword: $H{\infty}$ control

Search Result 704, Processing Time 0.025 seconds

A Design on Robust Two-Degree-of-Freedom Multivariable Boiler-Turbine System (강인한 2자유도 다변수 보일러-터빈 시스템의 설계)

  • Hwang, C.S.;Kim, D.W.;Jung, H.S.;Lee, D.Y.;Cho, K.Y.;Nam, K.W.
    • Proceedings of the KIEE Conference
    • /
    • 1995.07b
    • /
    • pp.670-672
    • /
    • 1995
  • This paper deals with the robust two-degree-of-freedom multivariable control system using $H_{2}/H{\infty}$optimization method which can achieve the robust stability and the robust performance, simultaneously. The feedback controller can obtain the robust stability property. The feedforward controller can obtain the robust performance property under modelling error. The robust two-degree-of-freedom multivariable control system is applied to the nonlinear multivariable boiler-turbine system. The validity of the proposed method is verified though being compared with LQG/LTR design method.

  • PDF

Fault tolerant control for remotely piloted vehicle (원격조종 비행체의 이상허용 제어)

  • Kim, Dae-Woo;Son, Won-Ki;Kwon, Oh-Kyu
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.5 no.6
    • /
    • pp.683-690
    • /
    • 1999
  • This paper deals with a fault-tolerant control method for robust control of RPV(Remotely Piloted Vehicle). To design the flight control system, the 6-DOF simulation program has been developed based on the dynamic model of RPV. A robust fault detection and diagnosis method proposed by Kwon et al. [8]-[10] is adopted to detect the actuator fault of RPV and to make the controller reconfiguration. The Hoo control method is applied to the flight control system. An integrated simulation for performance evaluation of the fault-tolerat\nt control system designed is performed via 6 DOF simulation and shows that the control system works even under the actuator fault.

  • PDF

ROBUST CONTROLLER DESIGN FOR IMPROVING VEHICLE ROLL CONTROL

  • Du, H.;Zhang, N
    • International Journal of Automotive Technology
    • /
    • v.8 no.4
    • /
    • pp.445-453
    • /
    • 2007
  • This paper presents a robust controller design approach for improving vehicle dynamic roll motion performance and guaranteeing the closed-loop system stability in spite of vehicle parameter variations resulting from aging elements, loading patterns, and driving conditions, etc. The designed controller is linear parameter-varying (LPV) in terms of the time-varying parameters; its control objective is to minimise the $H_{\infty}$ performance from the steering input to the roll angle while satisfying the closed-loop pole placement constraint such that the optimal dynamic roll motion performance is achieved and robust stability is guaranteed. The sufficient conditions for designing such a controller are given as a finite number of linear matrix inequalities (LMIs). Numerical simulation using the three-degree-of-freedom (3-DOF) yaw-roll vehicle model is presented. It shows that the designed controller can effectively improve the vehicle dynamic roll angle response during J-turn or fishhook maneuver when the vehicle's forward velocity and the roll stiffness are varied significantly.

The Robust Control of Two Mass Spring System (2관성 공진 시스템의 강건제어)

  • 조도현;이종용;이상철
    • Journal of the Korean Institute of Telematics and Electronics T
    • /
    • v.35T no.3
    • /
    • pp.76-86
    • /
    • 1998
  • The Two-Mass Spring(TMS or Two-Inertia Resonance) system is one of the simplest models which generate a torsional vibration. In this system, it is required to design a controller achieving the control performance while suppressing the torsional vibration. In this paper, we compared and considered with the state feedback effects for the TMS system. By connecting each controller design to the state feedback control, we could predict each controller performances and decide weighting functions and parameters of LQ and $H_\infty$ controller.

  • PDF

Development of a Robust Controller for Piezo/beam Systems (압전/빔 시스템에 대한 강건제어기 개발)

  • 홍성일;박현철;박철휴
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.14 no.7
    • /
    • pp.612-618
    • /
    • 2004
  • This paper presents a robust vibration control methodology for smart structural systems. The governing equation and associated boundary conditions of the smart structural system are derived by using Hamilton's principle. The assumed mode method is used to discretize the governing equation into a set of ordinary differential equation. A robust controller is designed using a linear matrix inequality (LMI) approach for the multiobjective synthesis. The design objectives are to achieve a mix of H$_{\infty}$ performance and H$_2$ performance satisfying constraints on the closed-loop pole locations in the presence of model uncertainties. Numerical examples are presented to demonstrate the effectiveness of LMI approach in damping out the multiple vibration modes of the piezo/beam system.

Development of the Robust Speed Controller for Marine Medium Speed Diesel Engines (선박용 중속 디젤 기관의 로바스트 속도제어기 개발)

  • Jung, B.G.;Yang, J.H.;Kim, C.H.
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.20 no.4
    • /
    • pp.349-349
    • /
    • 1996
  • The ship's propulsion efficiency depends upon a combibation of engine and propeller. The propeller has better efficiency as the engine has lower rotational speed. This situation led the engine manufacures to design the engine that has lower speed, longer stroke and a small number of cylinders. With this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variations of the delay-time and the parameter perturbation especially in low speed engine. In this study we consider the perturbations of the engine parameters as the modeling uncetainties and design a robust speed controller for marine medium speed diesel engine by means of $ extit{H}_{infty}$control theory having the central solution. By comparing the results of the robust speed controller with those of mechanical governor and PID controller, the validity of the robust speed controller under parameter variations is confirmed. The speed control of the experimental diesel engine of carried out using actuator which is composed of PWM signal generator and D.C servo motor.

H Control of Secondary Suspension in Railway Vehicles Equipped with a MR Damper (MR 댐퍼가 적용된 철도차량 이차현가장치의 H 제어)

  • Shin, Yu Jeong;You, Won Hee;Hur, Hyun Moo;Park, Joon Hyuk
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.30 no.10
    • /
    • pp.1051-1059
    • /
    • 2013
  • In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

Robust Filter Based Wind Velocity Estimation Method for Unpowered Air Vehicle Without Air Speed Sensor (대기 속도 센서가 없는 무추력 항공기의 강인 필터 기반의 바람 속도 추정 기법)

  • Park, Yong-gonjong;Park, Chan Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.47 no.2
    • /
    • pp.107-113
    • /
    • 2019
  • In this paper, a robust filter based wind velocity estimation algorithm without an air velocity sensor in an air vehicle is presented. The wind velocity is useful information for the air vehicle to perform precise guidance and control. In general, the wind velocity can be obtained by subtracting an air velocity which is obtained by an air velocity sensor such as a pitot-tube, and a ground velocity which is obtained by a navigation equipment. However, in order to simplify the configuration of the air vehicle, the wind estimation algorithm is necessary because the wind velocity can not be directly obtained if the air velocity measurement sensor is not used. At this time, the aerodynamic coefficient of the air vehicle changes due to the turbulence, which causes the uncertainty of the system model of the filter, and the wind estimation performance deteriorates. Therefore, in this study, we propose a wind estimation method using $H{\infty}$ filter to ensure robustness against aerodynamic coefficient uncertainty, and we confirmed through simulation that the proposed method improves the performance in the uncertainty of aerodynamic coefficient.

Modeling and adaptive optimal control of a twin roll strip caster (쌍롤형 박판주조기의 모델링과 적응최적제어)

  • 김성훈;홍금식;이교일
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.325-328
    • /
    • 1997
  • In this paper the modeling and control of a twin roll strip caster is investigated. Mathematical models for the strip casting process are obtained by analyzing five critical areas such that the molten steel level in the pool, solidification process, roll separating force and torque, roll dynamics including hydraulic actuators, and roll drive system. A two-level control strategy is proposed. At lower level, three local subsystems are independently feedback-controlled by suitable local controllers which perform well to the behaviors of each subsystem. They are a variable structure control of the molten steel level in the pool, an adaptive predictive control of the roll gap which is directly related to the strip thickness, and an $H^{\infty}$ control of the roll drive system. At higher level, all reference signals to the lower level subsystems are generated by an optimal controller in the perspective of regulating the strip thickness and roll separating force. Simulations are provided..

  • PDF

A New Anti Sway Control for Container Crane Using PSD Camera and Propellers (PSD 카메라와 프로펠라를 이용한 콘테이너 스웨이 제어)

  • Choe, Yeon-Wook;Lee, Hyung-Ki
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.56 no.5
    • /
    • pp.958-965
    • /
    • 2007
  • The spreaders on container cranes are usually controlled to stop at the same time as their trolleys are stopped. Despite the use of adequate control systems, however, the spreaders usually have comparatively large sway movements, due to their suspension from the trolleys through cables. It is, therefore, important to accurately measure the attitudes of the spreaders, in order to suppress such sways by means of secondary control. Until now, most of conventional anti sway control systems focus on the direct control of the movements of trolleys. which seems not suitable to speed up the entire process - loading and unloading of containers. In this paper, we suggest a new anti sway control system: By using extra equipments - two propellers to suppress the sway and a PSD camera to measure the spreader's attitude - installed on the spreader and the trolley. the sway of the suspended load j, considerably suppressed. The effectiveness of the proposed scheme is verified by the computer simulation and experiment with the miniature of the container crane system.