• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.110-115
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• 2001

The spherical CVT, intended to overcome some of the limitations of existing CVT designs, is marked by its simple kinematic design, improved efficiency of the shift actuator, and IVT characteristics, i.e., the ability of smooth transition between the forward, neutral, and reverse states without the need for any brakes or clutches. And it has been promised much possibility of energy savings and various applications for small power capacity machinery. Due to the nonlinearity of the spherical CVT shifting dynamics, however the original open-loop system is inherently unstable. Hence a feedback controller is necessary to make the system stable and to achieve effective tracking performance. To do this, we designed a feedback controller that cancels nonlinearities and transforms the original nonlinear system dynamics into a stable and controllable linear one, based on the input-state linearization method.

• 대한전기학회논문지
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• 제34권12호
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• pp.472-484
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• 1985

A design of robust voltage controller for high speed excitation of synchronous machine was carried out by pole assignment techniques. An affine map from characteristic polynomial coefficients to feedback parameters is formulated in order to place the system eigen values in the desired region. The feedback parameters determined from linearized model are tested on nonlinear model subjecting it to small disturbances and system faults to show the effectiveness of the controller designed by the proposed technique. The results obtained indicate that the controller presented improves the dynamic stability and system performances of conventionally controlled synchronous machine significantly.

• 한국추진공학회지
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• 제2권2호
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• pp.38-46
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• 1998

본 연구에서는 강인성 제어의 한 분야인 LQG용 observer를 이용한 단축 터보 젯 엔진의 RPM 속도제어에 대하여 이론을 전개하고 실제 엔진 모델에 대한 시뮬레이션을 실시하였다. 일반적인 시불변 선형연속 시스템에 대하여 상태 출력 궤환 제어기를 설계하여 asymptotic stability를 얻기 위한 충분 조건을 도출하고, 다음으로 실제 터보 젯 엔진으로부터 구한 시스템 모델에 대하여 observer를 이용하여 추적 제어를 실시하였다. 실제 엔진과 더 가까운 상황을 재현하기 위해 제어 입력부의 saturation을 함께 고려하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.696-698
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• 2004

In this paper we design $H_{\infty}$ infinity controller for Induction motor with low speed operation. $H_{\infty}$ controller is applied in order to design a state feedback static controller for field oriented control of an induction motor. $H_{\infty}$ controller are linear plant can be set up using the same assumptions that are at the basis of field oriented control. Thus, $H_{\infty}$ control theory can be successfully used to set up a state feedback controller for field oriented control of an induction motor. The performances of the $H_{\infty}$ controller is numerically analysed and experimentally verified to prove the validity of the design procedure. In this paper show that performances with high robustness to variations of system parameter.

• 전자공학회논문지SC
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• 제41권3호
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• pp.9-16
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• 2004

본 논문에서는 시변 시간지연을 가지는 특이시스템에 대한 관측기 기반 Η∞ 출력궤환 제어기 설계방법을 단 하나의 선형행렬부등식 조건을 이용하여 제시한다. 제어기가 존재할 충분조건과 제어기 설계방법을 모든 변수의 견지에서 완벽한 하나의 선형행렬부등식으로 표현하여 볼록최적화가 가능하도록 한다. 제어기의 설계과정은 제안한 하나의 충분조건으로부터 직접 구해진다. 구한 충분조건은 하나의 선형행렬부등식으로 표현되어지므로, 슈어 여수정리와 변수치환 및 특이치 분해의 기법에 의하여 궤환이득과 추정이득을 포함하는 모든 해로부터 관측기 기반 Η∞ 출력궤환 제어기를 동시에 구할 수 있다. 또한 제안한 알고리듬을 이용하여 파라미터 불확실성과 시간지연을 가지는 특이시스템에 대한 관측기 기반 견실 Η∞ 출력제환 제어기 설계도 가능함을 보인다. 마지막으로, 제안한 알고리듬의 타당성을 수치예제를 통하여 확인한다.

• 산업기술연구
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• 제18권
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• pp.303-308
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• 1998

In this paper a neural network controller called "Feedback-State Learning" for control of the attitude of a wheeled inverted pendulum is presented. For the controller the design of a stable feedback controller is necessary, so the LQR is used for the feedback controller because the LQR has good performance on controlling nonlinear systems. And the neural networks are used for a feed forward controller. The designed controller is applied to the stabilization of a wheeled inverted pendulum. Because of its nonlinear characteristics such as friction and parameter variations in the linearization, the wheeled inverted pendulum is used for demonstration of the effectiveness of the proposed controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.331-331
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• 2000

This paper presents the mixed $H_2/H_{\infty}$ output feedback controIler design method for linear systems with delayed state. The objective is to design the output feedback controller which minimizes the H$_2$-norm of one transfer function while ensuring the H$_{\infty}$-norm of the other is held below a chosen level. When objective is tormulated in terms of a common Lyapunov function, the sufficient conditions of existence of mixed $H_2/H_{\infty}$ controller are given in terms of LMIs. terms of LMIs.

• 전기학회논문지
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• 제56권2호
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• pp.383-388
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• 2007

This paper considers a low-order dynamic output feedback controller design problem. Since the proposed control law inherently has a low-pass filter property, it can alleviate the mal-effects of the sensor noise without additional filter designs. Frequency domain analysis shows the characteristics of the proposed control law against measurement noise. The effectiveness of the proposed control law is illustrated by numerical simulations with a rotary inverted pendulum and a convey-crane. Using only one integrator the proposed control law has the advantage to the stabilization problem with sensor noise as well as it can successfully replace the measurements of derivative terms in a state feedback control law.

• 전기학회논문지
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• 제58권9호
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• pp.1821-1826
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• 2009

An adaptive neural controller for perturbed strict-feedback nonlinear system is proposed. All the previous adaptive neural (or fuzzy) controllers are based on the backstepping scheme where the universal approximators are employed in every design steps. These schemes involve virtual controls and their time derivatives that make the stability analysis and implementation of the controller very complex. This fact is called 'explosion of complexty ' since the complexity grows exponentially as the system dynamic order increases. The proposed adaptive neural control scheme adopt the backstepping design procedure only for determining ideal control law and employ only one neural network to approximate the finally selected ideal controller, which makes the controller design procedure and stability analysis considerably simple compared to the previously proposed controllers. It is shown that all the time-varing signals containing tracking error are stable in the Lyapunov viewpoint.

• 제어로봇시스템학회논문지
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• 제2권1호
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• pp.1-4
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• 1996

This paper presents a state feedback $H^{\infty}$ controller design method for linear systems with delayed states and inputs. We derive a sufficient condition that the closed-loop system is asymptotically stable for all time-delays and that the $H^{\infty}$-norm of the closed-loop transfer function is less than or equal to some prescribed level $\gamma$. And we propose a sufficient condition for the existence of a state feedback $H^{\infty}$ controller using a form of linear matrix inequality(LMI). Furthermore, we show that the state feedback $H^{\infty}$ controllers can be obtained from solutions satisfying LMI.