• 한국소음진동공학회논문집
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• 제15권7호
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• pp.878-884
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• 2005

This paper presents an algorithm for the precision motion control based on the dynamic characteristics of piezoelectric actuators in the inchworm. The dynamic characteristics are identified by the frequency domain modeling technique using the experimental data. For the motion control, the hysteresis behavior is compensated by the inverse hysteresis model. The dynamic stiffness of an inchworm is generally low compared to its driving condition, so mechanical vibration may degenerate the motion accuracy of the inchworm. The Sliding mode controller and the Kalman filter are designed for motion control of the inch-worm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.26-28
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• 2004

The sliding mode control law provides a robust solution for general control problems. Most real systems which use a portable hard disk drive have to overcome disturbances and model uncertainties for proper operation. The chattering effect caused from unexpected oscillation can make the system be unstable. Therefore, we propose a robust control algorithm for the nonlinear second order systems with model uncertainties and disturbances. The proposed algorithm is designed following a sliding mode and observer based control. Thus the proposed algorithm has more expanded bounded region of control. Simulation results show the robustness of the proposed controller.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.1219-1226
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• 1993

A buck-boost zero current switched(ZCS) series resonant AC to DC converter for the DC output voltage regulation together with high power factor is proposed. The proposed single phase AC to DC converter enables a zero current switching operation of all the power devices allowing the circuit to operate at high swtiching frequencies and high power levels. A dynamic model for this Ac to DC converter is developed and an analysis for the internal operational characteristics is explored. Based on this analysis, a switched discrete sliding mode control(SDSMC) technique is investigated and its advantages over the other types of current control techniques are discussed. With the proposed control technique, the unity power factor without a current overshoot and a wide range of output voltage can be obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1759-1760
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• 2008

This paper proposes a neural network(NN)-based adaptive sliding mode controller for discrete-time nonlinear systems. By using disturbance estimation technique, a sliding mode controller is designed, which forces the sliding variable to be zero. Then, NN compensator with hidden-layer-to-output-layer weight update rule is combined with sliding mode controller in order to reduce the error of the estimates of both disturbances and nonlinear functions. The whole closed loop system rejects disturbances excellently and is proved to be ultimately uniformly bounded(UUB) provided that certain conditions for design parameters are satisfied.

• 대한전자공학회논문지
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• 제25권3호
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• pp.262-268
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• 1988

In this paper conditions are derived, which ensure the existence of a quasi-sliding mode on the control switching hyperplane in discrete variable structure control systems and also remove the reaching phase problem observed in continuous-time variable structure systems. In addition, a discrete variable structure tracking controller which has adaptive properties is devised based on these results. This controller has useful properties, such as small sensitivity to the variation of plant parameters and to disturbances and its performing speed is fast compared to that of other adaptive controller.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.906-908
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• 1999

In this paper, new sliding mode surfaces are proposed by defining novel virtual states. These sliding surfaces have nominal dynamics of an original system and makes it possible that the Sliding Mode Control(SMC) technique is used with the various types of controllers. Its design is based on the augmented system whose dynamics have m-th higher order than those of the original system where m is the number of inputs. The reaching phase is removed by setting the initial virtual states which makes the initial switching functions equal to zero.

• 해양환경안전학회지
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• 제13권2호
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• pp.169-172
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• 2007

본 논문은 Z-형 컨버터와 수정된 공간벡터 PWM인버터로 구성된 분산전원시스템의 회로모델과 제어 알고리즘을 보여주고 있다. Z-형 컨버터는 수동소자인 L과 C로 간단히 구성되어 있으며 인버터의 상하 양 소자가가 동시에 도통되도록 하는 구간을 이용해 승압을 함으로써 기존의 DC/DC 변환기와는 다른 형태를 취하고 있다. 점근 관측기를 이용한 이산시간 슬라이딩모드제어를 통해 전류제어를 함으로써 센서수를 줄이고 제어성능을 개선하였다. 대체에너지로 관심이 많은 태양광이나, 연료전지 그리고 소형 풍력발전으로부터 생산된 직류 에너지를 상용으로 사용할 수 있도록 하는 전력변환기로써 유용하게 사용될 수 있을 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.63.6-63
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• 2002

The technique of backstepping have can avoid cancellations of useful nonlinearities. It is widely used in nonlinear adaptive control. But it is difficult to use this technique for uncertain nonlinear systems. Sliding mode control has robustness and application with feedback linearization. This paper shows that the robustness can be used for back stopping technique to solve the uncertainty problem and to improve the scalar design problem using Control Lyapunov function which is the motivation of back stepping technique with recursive design for high-order systems. In the respect of SMC, the result of this paper does not need to satisfy the matching condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.806-807
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• 2011

This paper presents a new sensorless controller used with both the classical sliding mode observer(SMO) and the rate of current change in order to a reduced torque ripple for switched reluctance motor (SRM) sensorless drives. The new sensorless scheme consists of a sliding mode observer (SMO)-based position sensorless approach for high speeds along with a low-resolution discrete the rate of current change for low speeds and standstill. The new position estimation resets between the SMO and the low-resolution of current change according to the speed sign and the position error difference between the SMO and the low-resolution rate of current change. The simulation results show the robustness of this new high performance sensorless control approach with the hybrid sensorless control topology.

• 한국지능시스템학회논문지
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• 제16권6호
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• pp.747-752
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• 2006

본 논문에서는 두 개의 시스템으로 구성된 적응 퍼지 슬라이딩 모드 제어기의 설계를 제안한다. 제안한 슬라이딩 모드 제어기는 두 개의 시스템입력으로 구성된다. 기존의 슬라이딩 모드 제어기는 $approximation{\^{u}}(t)$에 불연속항 sgn함수나 sat함수를 추가하여 상태궤적을 sliding surface로 보내는 제어 기법을 사용하고 있다. 본 논문에서는 이러한 기존의 제어기에 또 하나의 불연속항 제어기를 추가하여 불확실한 제어 이득에 의한 disturbance를 줄여주고, 불확실한 외란에 강인한 제어기설계와 알지 못하는 실제 비선형 시스템과 퍼지 시스템 간의 오차에 의한 불안정성도 해결할 수 있는 제어기를 제안하였다. 또한 본 논문에서는 Fuzzy tuning을 통해 슬라이딩 조건을 가변화함으로써 기존의 슬라이딩 모드 제어기에 비해 빠르고 정확하게 추종 가능하도록 제어기의 성능을 향상시킨다. 기존의 슬라이딩 모드 제어방식에서는 ${\eta}$값을 임의의 양의 상수로 두고 설계를 하였다. 하지만 이러한 방식은 높은 overshoot를 발생하게 하거나 늦은 정정시간을 갖게 하였다. 이를 해결하기 위하여 본 논문에서는 state의 각 상황에 맞는 ${\eta}$값을 fuzzy tuning을 통하여 유도해 내어 overshoot를 줄이며 동시에 정정시간도 줄여 제어성능을 높이는 방법을 제안한다.