• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3073-3076
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• 1999

In this paper, $H_{\infty}$ two-degree-of freedom(2-DOF) model following control method is applied for the control of a brushless servo motor to achieve high robust performance. The proposed robust control algorithm designed to meet the robust stability and performances present that the robust control method is superior to conventional control methods in controlling the speed and position of a servo motor. The designed controller is implemented as an outer loop controller to a factory designed motor-servopack system. It is illustrated by simulations that the proposed method is effective to control servo systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1018-1020
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• 1996

In this paper, when a robust active noise controller for a small cavity to control the noise induced in the cavity is designed, the Graphical method based on the robust stability and performance requirements is studied. The problem of designing controller that achieve these robust performance conditions is related to minimizing the $H_{\infty}$ norm of the mixed sensitivity function by using $H_{\infty}$ control theory. Also, For design the controller, the loopshaping method which control the weight functions to satisfy the design specification without loss of a robust performance can be used. Therefore, we determined the acceptable design specification with the system characteristics of the small cavity and obtained its robust controller with the robust performance specifications by stability margin.

• Journal of Advanced Marine Engineering and Technology
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• 제35권6호
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• pp.820-828
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• 2011

에너지 절약은 해상운송분야에서 이익을 내기 위한 가장 중요한 요인 중 하나이다. 연료 소비율을 낮추기 위해서는 가능한 한 선박의 추진효율을 높여야만 한다. 추진효율은 추진기관과 낮은 회전속도에서 더 좋은 효율을 갖는 프로펠러의 조합에 의존한다. 기관은 저속이 될수록 연료분사과정에서의 지연시간으로 인해 회전 토크 변동이 심해진다. 본 연구에서는 강인 제어이론을 적용하여 강인 안정성과 강인 성능을 고려한 기관 속도제어기들, 즉 준최적 $H_{\infty}$제어기, $H_{\infty}$루프-성형 제어기 및 ${\mu}$-제어기를 설계한다. 컴퓨터 시뮬레이션 결과로부터 이들 3가지 제어기의 타당성을 검토한다.

• 제어로봇시스템학회논문지
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• 제8권9호
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• pp.747-756
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• 2002

The automatic steering system for unmanned vehicle was developed. The magnet and MR (Magnetoresistive) sensors are used for the tue detecting system. The lateral distance between sensor and the center line of the road is determined by the linearization of the distance according to the output. The PD control theory is used for the design of the controller to compare with $H_\infty$ control theory. The $H_\infty$ control theory is used for the design of the controller to reduce the disturbance. The performance of the PD controller and $H_\infty$ controller is compared in simulations and tests. The PD controller is easy to tune in the test site. The $H_\infty$ controller is robust far the disturbances in the test results.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1700-1705
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• 2003

In this paper, the automatic steering system for unmanned vehicle was developed. The vision system is used for the lane detection system. This paper defines two modes for detecting lanes on a road. First is searching mode and the other is recognition mode. We use inverse perspective transform and a linear approximation filter for accurate lane detections. The PD control theory is used for the design of the controller to compare with $H_{\infty}$ control theory. The $H_{\infty}$ control theory is used for the design of the controller to reduce the disturbance. The performance of the PD controller and $H_{\infty}$ controller is compared in simulations and tests. The PD controller is easy to tune in the test site. The $H_{\infty}$ controller is robust for the disturbances in the test results.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권10호
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• pp.562-570
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• 1999

In the industrial motor drive system which is composed of a motor and load connected with a flexible shaft, a torsional vibration is often generated because of the elastic elements in torque transmission. This vibration, which is generated in a two-mass mechanical system. To solve this problem, recently there has been a lot of researches for the robust control relevant to the $H_{\infty}$ control suppressing the torsional vibration and rejecting the torque disturbance. In the case of the $H_{\infty}$controller, however, the command tracking property becomes worse because of overshoot during transient response. For this reason the $H_{\infty}$ controller, which includes the two-degrees-of-freedom(TDOF) controller, is designed in order to improve command tracking property. However, it also includes complexity realizing this controller. In this paper, a new $H_{\infty}$ controller with partial state feedback is proposed. Proposed $H_{\infty}$controller has simple structure but satisfies with the fast command tracking property and the attenuation of disturbances and vibrations simultaneously, just like the complicated TDOF $H_{\infty}$ controller.

• 한국소음진동공학회논문집
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• 제25권5호
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• pp.361-368
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• 2015

This paper deals with a robust fine seek controller design problem with multiple constraints using a genetic algorithm. A robust $H\infty$ constraint is introduced to attenuate effectively velocity disturbance caused by the eccentric rotation of the disk. A weighting function is optimally selected based on the estimation of velocity disturbance and the estimated minimum velocity loop gain. A robust velocity loop constraint is considered to minimize the variances of the velocity loop gain and bandwidth against the uncertainties of fine actuator. Finally, a robust fine seek controller is obtained by solving a genetic algorithm with an LMI condition and an appropriate objective function. The proposed controller design method is applied to the fine seek control system of a DVD recording device and is evaluated through the experimental results.

• 한국해양공학회지
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• 제10권3호
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• pp.153-161
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• 1996

This paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{\infty}$ control technique. The norm band of uncertainty is captured by multiplicative perturbation between nominal model and reduced order model. A controller robust to the uncertainty is designed applying $H_{\infty}$ synthesis. The control law satisfying robust stabillity and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{\infty}$ synthesis is done through simulations of the closed loop system. The results of $H_{\infty}$ synthesis are compared to those of the traditional LQ synthesis method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.437-442
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• 1996

The paper presents a design method of dynamic positioning control system for floating platform with rotatable and retractable thruster using $H_{\infty}$control technique. The norm band of uncertaintyis captured by multiplicative perturbation between nominalmodel and reduced order model. A controller robust to theuncertainty is designed applying $H_{\infty}$synthesis. The control law satisfying robust stability and nominal performance condition is determined through the mixed sensitivity approach. The evaluation for the resultant controller obtained by $H_{\infty}$synthesis is done through simulations of the closed loop system. The results of $H_{\infty}$synthesis are compared to those of the traditional LQ synthesis method. method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.586-591
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• 1992

In this paper a robust stabilization problem is discussed for plant with both time-varying parameter perturbations and unstructured uncertainty. It is shown that, a robust L$_{2}$-stabilizing controller can be obtained by solving an H$_{\infty}$ standard problem with a scaling parameter. Using an H$_{\infty}$ design method, a robust L$_{2}$-stabilizing controller is derived. Finally, a numerical example is given.n.