• Journal of IKEEE
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• v.9 no.2 s.17
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• pp.87-100
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• 2005

In this paper, a design of an integral augmented optimal variable structure system(IOVSS) is presented for the prescribed output control of uncertain SISO systems under persistent disturbances. This algorithm aims at removing the problems of the reaching phase by incorporating advanced optimal control theory. By means of an integral sliding surface, the reaching phase is completely removed, and the integral sliding surface can be defined from a given initial state to origin without any reaching phase. The ideal sliding dynamics of the integral sliding surface is obtained in the form of the state equation and is designed in an optimal sense by targeting the design of the integral sliding surface and equivalent control input. The corresponding control input is selected in order to generate the sliding mode on the predetermined integral sliding surface. As a result, the whole sliding output from a given initial state to origin is completely guaranteed against persistent disturbances. Moreover the prediction/predetermination of output is enabled, which helps in improving the performance over previously implemented VSS's. Through an illustrative example, the usefulness of the algorithm is shown.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1203-1211
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• 2017

This paper proposes a robust controller for flexible joint robots to achieve tracking performance and to improve robustness against both matched and mismatched disturbances. The proposed controller consists of a disturbance observer(DOB), passivity-based controller, and integral sliding mode controller(ISMC) in a backstepping manner. The DOB compensates the mismatched disturbance in the link-side and formulates the reference input for the motor-side controller. Interconnection and damping assignment passivity-based controller (IDA-PBC) performs tracking control of motor-side, and it is integrated to nominal control of ISMC to guarantee the over-all stability of the nominal system, while, matched disturbances are decoupled by the discontinuous control of ISMC. In the design of the link-side controller, PD type impedance controller is designed with DOB and this leads the continuous control input which is suitable to the reference input for the motor-side.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1998.03a
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• pp.313-319
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• 1998

본 논문에서는 슬라이딩모드 제어이득을 실시간으로 계산하여 적응시키는 적응 가변구조제어기 설계방법을 제시한다. 제시된 방법은 간단한 계산으로 슬라이딩모드제어의 조건을 만족시키도록 제이이득을 변화시키므로 채터링을 감소시키고 추적오차성능을 개선시킨다. 계산시간이 적어 실시간 제어에 적용이 쉬운 장점이 있다. 제시된 제어방법을 기존의 방법과 비교하여 설계의 예를 보였고 시뮬레이션을 통하여 제시된 방법의 유용성을 보였다.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.223-224
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• 2007

초정밀 위치 제어 시스템에서 미지의 상태변수를 관측하는 경우, 파라미터의 불확실성은 관측기 설계에 많은 어려움을 주게 된다. 슬라이딩 모드 관측기는 불확실성과 외란이 존재하는 시스템의 상태변수를 관측가능하게 하며 강인한 성능을 보여준다. 본 논문에서는 불확실성이 존재하는 시스템의 관측기를 설계하고 최적제어를 통하여 정밀 스테이지의 위치를 제어하며, 시뮬레이션을 통해 개선된 성능을 입증한다.

• Proceedings of the KIPE Conference
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• 2017.07a
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• pp.244-245
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• 2017

본 논문은 병렬-입력 직렬-출력 구조의 모듈형 DAB (Dual active bridge) 컨버터의 출력 전압 평형 제어기법을 제안한다. 이를 위해, 먼저 모듈형 DAB 컨버터를 모델링하고 계층형 슬라이딩모드(Hierarchical SMC) 제어기를 설계한다. 제안된 기법을 시뮬레이션을 통해 검증한다.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.91-92
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• 2015

본 논문에서는 DAB(Dual Active Bridge) 타입의 절연형 양방향 DC/DC 컨버터의 출력전압 제어기법을 제시한다. SPS(Single-phase shift) PWM 기반의 고조파 모델에 대해 슬라이딩 모드 제어기(SMC)를 설계한다. 제시된 기법은 시뮬레이션 결과에 의해 성능이 검증된다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.95-100
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• 2004

A control alogorithm using sliding mode and neural network for Buck type DC-DC converter is presented. Also, we conform a rightness the proposal method by comparing a theoretical values and experimental values obtained from experiment using DSP(digital signal processor). Performance comparisons made with the general hysteresis controller clearly bring out the superior performance of the proposal neural network controller. This paper will be applied to other power conversion system using the proposal neural network controller.

• New & Renewable Energy
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• v.7 no.3
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• pp.74-82
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• 2011

Because concern on the problem of the limited energy is growing and the wind energy is considered as one of the biggest solutions, the researches on the wind energy and turbine are accomplished vigorously. The simulation tools on the non-linear characteristics of wind turbine system are various and it could describe the non-linear characteristics well but, the tool and methodology to apply non-linear control theory rarely exist. In this paper, the application procedure of sliding mode control theory to 2-DOF non-linear wind turbine system is suggested and the application results of it are also shown as compared with a torque loop control theory.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.964-965
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• 2008

본 논문은 고속 영구자석형 동기전동기의 센서리스 제어에 관한 것이다. 정지상태에서 초기 기동시 부터 고속영역까지 센서리스 알고리즘을 구현하기 위하여 슬라이딩 모드 관측기를 적용하여 회전자의 회전각을 실시간으로 관측하여 벡터제어 알고리즘을 구현하였다. 슬라이딩 모드 관측기의 채트링을 개선하고 넓은 속도 범위에서 안정된 응답을 얻기 위하여 속도에 따른 가변 이득 알고리즘과 관측기의 수렴을 여부를 판별하여 제한된 PWM 주기 내에서 관측기를 반복수행 관측기의 성능을 개선하는 알고리즘을 제안 하였다. 또한 제안된 알고리즘을 실험을 통하여 검증을 하였다. 초기 기동시 및 고속 영역에서 우수한 성능의 센서리스 알고리즘 구현되었을 확인하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.129-138
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• 2021

Due to the active progress in space programs for various types of ground and space missions, the high agile spacecraft maneuverability is also required. To meet the requirement of the given space missions, the Control Moment Gyros (CMG) for the alternatives of the classical reaction wheels can release the attitude maneuverability restrictions. In addition, the angular rates of the spacecraft is constrained due to the limited actuator characteristics. In this paper, a sliding mode control technique for the attitude control of the spacecraft equipped with the pyramid type of CSCMG(Constant Speed CMG) is designed, and the stability of the control system is guaranteed by using the Lyapunov stability theory. Finally, the control law proposed is analyized by numertical simulations.