• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.1
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• pp.46-53
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• 2000

본 논문에서는 전원전압 센서 없는 단상 PWM 컨버터의 전류제어방법을 제안한다. 제안된 방법에서 전원전압은 슬라이딩 모드 관측기에 의해 추정되며 추정된 전원전압을 이용하여 컨버터의 입력 역률을 '1'로 하고 일정한 DC링크전압을 얻을 수 있다. 제안된 방법의 특징은 전원전압의 크기와 위상의 추정이 실제전류와 추정전류의 전류오차에 의해서 얻어질 수 있다. 제안된 방법은 DSP를 이용하여 구현하고, 실험결과는 제안된 방법의 정당성을 입증한다.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2664-2666
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• 2000

In this paper, the novel sliding mode control method with virtual state is compared to the SMC with co-states. The former method is shown to have advantage in the respect of computation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.38 no.6
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• pp.28-36
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• 2001

A robust adaptive sliding mode robot control algorithm is derived, which consists of a feed-forward compensation part and discontinuous control part. The unknown parameters is categorized into two groups, with group containing the parameters estimated on-line, and group containing the parameters not estimated on-line. Then a sliding control term is incorporated into the torque input in order to account for the effects of uncertainties on the parameters not estimated on-line and of disturbances. Moreover, the algorithm is computationally simple, due to an effective exploitation of the structure of manipulator dynamics. It is shown that, despite the existence of the parameter uncertainty and external disturbances, the controller is globally asymptotically stable and guarantees zero tracking errors.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.527-532
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• 2005

In this paper, we proposed an adaptive fuzzy sliding control for unknown nonlinear systems using estimation of bounds for approximation errors. Unknown nonlinearity of a system is approximated by the fuzzy logic system with a set of IF-THEN rules whose consequence parameters are adjusted on-line according to adaptive algorithms for the purpose of controlling the output of the nonlinear system to track a desired output. Also, using assumption that the approximation errors satisfy certain bounding conditions, we proposed the estimation algorithms of approximation errors by Lyapunov synthesis methods. The overall control system guarantees that the tracking error asymptotically converges to zero and that all signals involved in controller are uniformly bounded. The good performance of the proposed adaptive fuzzy sliding mode controller is verified through computer simulations on an inverted pendulum system.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.179-180
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• 2008

본 논문에서는 극배치(pole placement) 제어 시스템의 상태들에 의해서 훈련된 신경 회로망(Neural Network)을 기반으로 새로운 슬라이딩 평면의 설계 기법을 제안한다 훈련된 데이더를 가진 신경 회로망은 배치 제어의 성능을 가지며 새로운 슬라이딩 평면을 설계하는데 사용되어 진다. 그 결과 시스템의 파라미터 불확실성이 존재하더라도 제안된 슬라이딩 평면으로서 슬라이딩 모드 제어의 강인성이 신경회로망을 통한 극배치제어의 성능에 추가되는 것이 가능하다.

• Journal of the Korean Society for Precision Engineering
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• v.9 no.3
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• pp.42-52
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• 1992

가변구조 제어시스템(variable structure control system)을 위해 제안된 기존의 대부분 슬라이딩 서피스 (sliding surface)는 주어진 초기조건과 무관하게 설계되었으며, 서피스 계수 또는 임의로 설정되었다. 이러한 서피스를 갖는 제어시스템은 슬라이딩 운동이 일어나기 전까지 외란등에 매우 민감하며 또한 느린 추적시간 (tracking time)을 초래한다. 이러한 단점을 극복하기 위해 본 연구에서는 임의로 주어진 초기조건을 항상지나 며 시간에 따라 기울기 및 절편이 변하는 새로운 슬라이딩 서피스를 설계하였다. 이 서피스와 연계된 제어시스 템의 슬라이딩 모드(sliding mode) 존재성을 증명하였고, 서피스의 움직임 절차를 상세히 기술하였다. 2차 선형 시스템과 2자유도계 로봇의 추적제어를 통해 제안된 방법의 효율성과 우수성을 입증하였다.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.2
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• pp.20-26
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• 2008

The most vehicle active suspension system is activated by a hydraulic source and transmission system which has nonlinear characteristics. Even though we have designed a proper controller for this system, it sometimes cannot show remarkable performance characteristics because of many factors that undercut the performance of the hydraulic system, such as nonlinearity, modelling errors, parameter variations etc. So, the robust controller that prevents a system from lowering its performance is needed. In this study, the sliding mode control which is the representative one of robust controllers is adopted to investigate system parameter sensibility. As a result, the sliding mode controller shows robustness to the system parameters variations relative to the other controllers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.12
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• pp.1817-1825
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• 2021

Omnidirectional mobile robots can be mobile in any direction without changing the robot's direction, making them easy to apply in many applications and providing excellent maneuverability. Omnidirectional mobile robots have non-linear dynamic components such as friction, making them difficult to model accurately. In this paper, we linearize the mobile robot system using the mobile robot's inverse dynamics and integral sliding mode control method to remove these nonlinear components. And the position and velocity gains are optimized using a genetic algorithm to realize the optimal performance of the proposed system control method. As a result of the performance evaluation, the genetic algorithm's control method showed superior performance than the control method with an arbitrary gain. And the proposed inverse dynamic and integral sliding mode control method can be applied to other control methods. It can be beneficial for designing a linear control system.

• Journal of Power System Engineering
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• v.9 no.4
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• pp.175-180
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• 2005

Incorrections between model and plant are parameter, system order uncertainties and modeling error due to disturbance like friction. Therefore to achieve a good tracking performance, adaptive discrete time sliding mode tracking controller is used under time-varying desired position. Based on the diophantine equation, a new discrete time sliding function is defined and utilized for the control law. Robustness is increased by using both a recursive least-square method and a sliding function-based nonlinear feedback. The effectiveness of the proposed control algorithm is proved by the results of simulation and experiment.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.10
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• pp.161-167
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• 2001

This paper presents an approach to nonlinear engine idle controller and intake manifold absolute pressure(MAP) observer based on mean torque production model. A stable engine idle speed is important in that the unstable engine Idle mode can make engine to drooping or stall state. A sliding fuzzy controller has been designed to control engine idle speed under load disturbance. A sliding observer is also developed to estimate the intake manifold absolute pressure and compared with the actual MAP sensor value. The sliding mode observer has shown good robustness and good tracking performance. The inputs of sliding fuzzy controller are the errors of rpm and MAP. The output is a duty cycle(DC) for driving a idle speed control valve(ISCV).