• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
• /
• pp.1539-1544
• /
• 1991

In this paper we formulate and solve a generalized $H^{\infty}$ control problem. The conventional formulation of $H^{\infty}$ problem has some constraints in application, e.g. it can not deal with the servo problem. This is due to the superfluous requirement of internal stability of the augmented system. In this paper, we alleviate the stability of the augmented system to admit pole-zero cancellation on the imaginary aids outside the feedback loop of G22 and K. After such generalization, the servo problem is naturally incorporated into the $H^{\infty}$ synthesis.is.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.75.2-75
• /
• 2001

In this paper, we provide the technique of H$\infty$ controller design algorithm for input-saturated linear systems using a linear parameter varying(LPV) framework. The LPV controller with parameter dependent dynamic state feedback controller concept guarantees the asymtotic stability and H$\infty$ norm bound within prescribed level v using the saturation nonlinearity as scheduling parameters. Especially, the sufficient conditions for the existence of H$\infty$ controller are formulated in terms of linear matrix inequalities(LMIs) that can be solved very efficiently.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
• /
• pp.34-39
• /
• 1991

In this paper, we provide a treatment of the $H^{\infty}$-mixed sensitivity optimization approach to feedback system design. With compromising between the effect of a disturbance at the plant output and the effect of plant perturbations, we propose an algorithm to design robust controller. A $H^{\infty}$-optimization problem is to be equivalent to a Hankel-approximation, this enables the problem to be solved using state-space methods based on balanced realizations.s.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.536-536
• /
• 2000

In this paper, we show based on Lyapunov theorem that the closed loop system with the constrained H$_{\infty}$ optimal controller is exponentially stable. Then the on-line feedback implementation of the constrained H$_{\infty}$ optimal control based on quadratic programs is proposed.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1995년도 춘계학술대회 논문집
• /
• pp.342-347
• /
• 1995

Loop shaping $H_{\infty}$control with normalized coprime factorization was applied to a servo-motor driven high-speed powitioning system. The high-gain controller was designed to attenuate the postion errors caused byfriction effects and extermal disturbances. The non-existence of limit cycle was analyzed, though there is actuator saturation. The designed $H_{\infty}$control system was experimently tested in a rotary index table. Results showed its effectiveness to improve postion accuracy with out any compensation scheme for friction, and robustness to model perturbation and external disturbances.ces.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
• /
• pp.93-99
• /
• 1998

Mathematical model can be obtained by physical law or engineering theory. However it is always incomplete expression of the real system. In active controls to suppress vibration due to earthquake or wind load, modeling errors can often cause the problems of instability and performance degradation. In this paper, robust optimal controller design method using H$\infty$ control theory is developed for the systems which have uncertain natural frequency and design constraints. Numerical results show that the proposed H$\infty$ controller can avoid the performance degradation due to several errors and has better performance than conventional LQR method.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
• /
• pp.161-166
• /
• 1998

In this paper, an approach to the reduced order H$_{\infty}$ controller synthesis is proposed. This approach employs the frequency weighted model reduction whose frequency weights are deduced from the closed-loop system regarding the controller order reduction errors as uncertainties in a plant, while the resultant reduced order H$_{\infty}$ controller guarantees prescribed H$_{\infty}$ control performances.

• 대한기계학회논문집A
• /
• 제24권8호
• /
• pp.1899-1909
• /
• 2000

This paper proposes a new $H_{\infty}$ yaw moment control scheme using brake torque switching for improving vehicle performance and stability especially in high speed driving. In the scheme, one wheel is selected, depending on the vehicle states, at which a brake torque for control is applied. Steering angles are modeled as a disturbance to the system and the $H_{\infty}$ controller is designed to minimize the difference between the performance of the vehicle and that of the desired model. Its performance robustness as well as stability robustness to system parameter variations is assured through ${\mu}$-analysis. Various simulations with a nonlinear 8-DOF vehicle model show that proposed controller enhances the vehicle performance and stability under disturbances and parameter variations as well as under the normal driving condition.

• 대한기계학회논문집A
• /
• 제36권11호
• /
• pp.1311-1318
• /
• 2012

본 논문에서는 차량 전복 방지를 위해 강인 제어기를 설계하고 적용하는 방법에 대해 제시한다. 운행 중인 차량은 속도나 무게중심과 같은 파라미터 변화가 쉽게 발생하는데, 차량 전복 방지 제어기가 파라미터 변화에 대해 강인하게 설계된다면 차량 전복 방지 성능을 더욱 향상시킬 수 있다. 이를 위해 본 논문에서는 이산시간영역에서 LMI 를 이용하여 $H_2$ 및 $H_{\infty}$ 강인제어기를 설계하고, 실험에 대한 신뢰도가 높은 차량 시뮬레이션 패키지인 CarSim 에서 차량 전복 방지를 위한 제어기의 성능을 검증한다.

• 전자공학회논문지SC
• /
• 제37권2호
• /
• pp.8-15
• /
• 2000

본 연구는 가중함수의 주파수 영역 해석에 의한 H∞ 최적 제어기를 설계하고 이를 대상 시스템에 적용하여 해석하였다. 이는 가중함수와 개 루프 전달함수에서 견실성을 만족하는 영역과 매개변수 γ의 최적 값이 존재하는 영역을 도시하고 H∞ 최적 제어기를 구성하기 위한 알고리즘을 간략화 시킬 수 있다. 또한 제안된 방법에 의해 설계된 제어기는 플랜트 불확실성의 변화에도 불구하고 어떠한 동작점에서도 원하는 사양과 성능을 만족하였다.