• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.32-33
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• 2014

This paper presents control performances of a seat suspension system equipped with magnetorheological (MR) dampers using a new adaptive fuzzy sliding mode controller (FSMC). Adaptive fuzzy controller is formulated by considering the acceleration of the seat. It has been demonstrated that the proposed seat suspension system realized by the adaptive fuzzy sliding mode controller can provide effective performances such as reduced vibration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.468-471
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• 2003

In this paper, a second order sliding mode control that combines with a fuzzy adaptation technique is presented for a nonlinear system with unknown dynamics. The chattering effect that is a representative disadvantage of the sliding mode control is avoided by using the second order sliding mode control instead of the first order sliding mode control. The proposed controller is composed of the equivalent control that is approximated by an online adaptation scheme and the hitting control that is used to constrain the states to maintain on the sub-sliding surface and used to guarantee the system robustness. Simulation results are presented to show the effectiveness of the proposed controller.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.93-99
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• 2003

One of the methods to simplify the design process for a fuzzy logic controller (FLC) is to reduce the number of variables representing the rule antecedent. This in turn decreases the number of control rules, membership functions, and scaling factors. For this purpose, we designed a single-input FLC that uses a sole fuzzy input variable. However, it is still deficient in the capability of adapting some varying operating conditions although it provides a simple method for the design of FLC's. We here design two simple-structured adaptive fuzzy logic controllers (SAFLC's) using the concept of the single-input FLC. Linguistic fuzzy control rules are directly incorporated into the controller by a fuzzy basis function. Thus some parameters of the membership functions characterizing the linguistic terms of the fuzzy control rules can be adjusted by an adaptive law. In our controllers, center values of fuzzy sets are directly adjusted by an adaptive law. Two SAFLC's are designed. One of them uses a Hurwitz error dynamics and the other a switching function of the sliding mode control (SMC). We also prove that 1） their closed-loop systems are globally stable in the sense that all signals involved are bounded and 2） their tracking errors converge to zero asymptotically. We perform computer simulations using a nonlinear plant.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1718-1719
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• 2007

In this paper, a fuzzy sliding mode control that combines with a adaptive self-regulating technique is proposed for manipulators with uncertainties. Especially the system uncertainties is approximated using fuzzy rule adaptation technique. The proposed controller is composed of the equivalent control that includes the approximation of the system uncertainties and the hitting control that is used to constrain the states of the system to maintain on the sliding surfaces and used to guarantee the system robustness. Simulation results are presented to show the effectiveness of the proposed controller

• 한국산업정보학회논문지
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• 제7권4호
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• pp.66-73
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• 2002

일반적으로 가변구조제어는 외란과 변수 변화에 대해 강인한 특성을 가지지만 제어기 설계자는 이러한 값들에 대한 상한 값과 하한 값을 알아야한다. 그러나 때로는 이러한 상한 값과 하한 값을 얻는다는 것은 쉽지가 않다. 이에 반해 퍼지제어기는 외란과 변수 변화에 대한 제어기 설계에 있어서 효과적인 방법을 제공한다. 따라서 퍼지제어기와 가변구조제어기가 가지는 장점들을 결합하는 연구가 진행되어져 왔다. 본 논문에서는 리칭페이저가 존재하는 기존의 슬라이딩모드제어기를 이용하는 방법 대신 리칭페이저를 제거하여 전 구간 강인한 적응 퍼지가변구조제어기를 설계하였다. 제안된 제어 알고리듬은 BLDC 전동기의 위치제어기로 사용하였으며, 그 타당성을 입증하였다.

• 한국지능시스템학회논문지
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• 제11권9호
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• pp.788-792
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• 2001

일반적으로 슬라이딩모드 제어는 외란이나 시스템의 변수변환에 강인한 특성을 가지나, 그 변화의 최대 경계 값을 알아야한다. 그러나, 이 값은 쉽게 얻어질 수가 없다. 퍼지 논리는 잘 정의되어 있지 않거나 복잡한 시스템의 제어기 설계에 효과적인 방법을 제시하나, 과도응답을 미리 결정할 수가 없다. 본 논문에서는 두 이론의 장점을 결합하여 새로운 제어 알고리듬을 제시한다. 최적의 퍼지변수 값을 결정하기 위하여 적응이론을 도입한다. 마지막으로 제안한 제어 알고리듬의 타당성을 살펴보기 위하여 수치적인 예를 가변길이진자시스템에 적용한다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.365-370
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• 2000

A sliding mode fuzzy control (SMFC) algorithm is applied to design a controller for a benchmark problem on a wind- excited building. The structure is a 76-story concrete office tower with a height of 306 meters, hence the wind resistance characteristics are very important for the serviceability as well as the safety. A control system with an active tuned mass damper is assumed to be installed on the top floor. Since the structural acceleration is measured only at ,limited number of locations without measurement of the wind force, the structure of the conventional continuous sliding mode control may have the feed-back loop only. So, an adaptive least mean squares (LMS) filter is employed in the SMFC algorithm to generate a fictitious feed-forward loop. The adaptive LMS filter is designed based on the information of the stochastic characteristics of the wind velocity along the structure. A numerical study is carried out. and the performance of the present SMFC with the ,adaptive LMS filter is investigated in comparison with those of' other control, of algorithms such as linear quadratic Gaussian control, frequency domain optimal control, quadratic stability control, continuous sliding mode control, and H/sub ∞///sub μ/, control, which were reported by other researchers. The effectiveness of the adaptive LMS filter is also examined. The results indicate that the present algorithm is very efficient .

• 한국지능시스템학회논문지
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• 제14권6호
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• pp.752-758
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• 2004

본 논문에서는 고전적인 슬라이딩 모드 제어에서 단점으로 나타나는 채터링을 감소시키고 도달 시간을 줄이기 위한 적응 퍼지 슬라이딩 모드 제어기를 제안하였다. 전문가의 경험이나 직관에 주로 의존하는 제어 규칙의 획득을 쉽게 하기 위해 최대 경사법을 이용하여 슬라이딩 모드 조건이 만족되면서 채터링 현상을 줄이기 위한 제어 규칙의 결론부 파라미터를 수정하는 적응 알고리즘을 제안하였다. 제안된 알고리즘은 고전적인 가변 구조 제어 시스템의 장점인 외란, 매개변수 변화와 불확실성에 둔감한 성질을 그대로 간직하고 있다. 제안한 알고리즘의 유용성을 보이기 위해 도립 진자 시스템에 적용한 결과 채터링 감소와 빠른 응답 특성을 얻을 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2292-2295
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• 2001

In this paper, The control problem for a series DC motor is considered to adaptive fuzzy sliding-mode control scheme. Based on a nonlinear mathematical model of a series connected DC motor, instead of the combination of a nonlinear transformation and state feedback(feedback linearization) reduces the nonlinear control design. To demonstrate its effectiveness, an experimental study of this controller is presented. Two sets of fuzzy rule bases are utilized to represent the equivalent control input with unknown system functions of the main target. The membership functions of the THEN-part, which is used to construct a suitable equivalent control of SMC, are changed according to the adaptive law. With such a design scheme, we not only maintain the distribution of membership functions over state space but also reduce computing time considerably.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1646_1647
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• 2009

In this paper, Takagi-Sugeno(T-S) fuzzy controller and search method are developed for efficiency optimization of induction motors(IMs). The proposed control scheme consists of efficiency controller and adaptive backstepping controller. A search controller for which information of input of T-S fuzzy controller is included in efficiency controller that uses a direct vector controlled induction motor. A sliding mode observer is designed to estimate rotor flux and an adaptive backstepping controller is used to control of speed of IMs. Simulation results are presented to validate the proposed controller.