• Journal of Advanced Marine Engineering and Technology
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• 제38권10호
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• pp.1318-1326
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• 2014

The purpose of a tracking control system is to track a moving target and to find the exact information of the target. If the platform of the tracking control system is equipped on a moving vehicle such as a ship, the tracking control system will treat even the additional platform motion. In order to avoid the complexity comprising the tracking control system, a process to treat the platform motion, named stabilizing system, must be separated from the tracking control system. In this paper, a method to comprise an attitude control system for the platform stabilization is proposed using an adaptive fuzzy control which is applicable to the system with structural and parametric uncertainty. The suggested adaptive fuzzy control algorithm is the 2nd/1st-type indirect adaptive fuzzy control algorithm using the advantages of 1st-type and 2nd-type indirect adaptive fuzzy control algorithm. Several experiments using the implemented stabilizing system are executed for verifying the effectiveness of the suggested method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권2호
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• pp.199-204
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• 2004

In this paper, a new dual-rate digital control technique for the Takagi-Sugeno (T-S) fuzzy system is suggested. The proposed method takes account of the stabilizablity of the discrete-time T-S fuzzy system at the fast-rate sampling points. Our main idea is to utilize the lifted control input. The proposed approach is to obtain the dual-rate discrete-time T-S fuzzy system by discretizing the overall dynamics of the T-S fuzzy system with the lifted control, and then to derive the sufficient conditions for the stabilization in the sense of the Lyapunov asymptotic stability for this system. An example is provided for showing the feasibility of the proposed discretization method.

• Transactions on Control, Automation and Systems Engineering
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• 제3권2호
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• pp.95-105
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• 2001

In this paper, in order to control uncertain chaotic system, an adaptive fuzzy control(AFC) scheme is developed for the multi-input/multi-output plants represented by the Takagi-Sugeno(T-S) fuzzy models. The proposed AFC scheme provides robust tracking of a desired signal for the T-S fuzzy systems with uncertain parameters. The developed control law and adaptive law guarantee the boundedness of all signals in the closed-loop system. In addition, the chaotic state tracks the state of the stable reference model(SRM) asymptotically with time for any bounded reference input signal. The suggested AFC design technique is applied for the control of an uncertain Lorenz system based on T-S fuzzy model such as stabilization, synchronization and chaotic model following control(CMFC).

• 대한전기학회논문지:전력기술부문A
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• 제49권2호
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• pp.62-69
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• 2000

In this paper, we design a GA-fuzzy precompensated PID controller for the load frequency control of two-area interconnected power system. Here, a fuzzy precompensated PID controller is designed as a fuzzy logic-based precompensation approach for PID controller. This scheme is easily implemented simply by adding a fuzzy precompensator to an existing PID controller. And we optimize the fuzzy precompensator with a genetic algorithm for complements the demerit such as the difficulty of the component selection of fuzzy controller, namely, scaling factor, membership function and control rules. Simulation results show that the proposed control technique is superior to a conventional PID control and a fuzzy precompensated PID control in dynamic responses about the load disturbances of power system and is convinced robustness reliableness in view of structure.

• 한국지능시스템학회논문지
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• 제10권5호
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• pp.423-431
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• 2000

In this paper, the effect of computing time-delay in the real-time digital fuzzy control systems is investigated and the design methodology of a real-time digital fuzzy controller(DFC) to overcome the problems caused by it is presented. We propose the fuzzy feedback controller whose output is delayed with unit sampling period. The analysis and the design problem considering computing time-delay is very easy because the proposed controller is syncronized with the sampling time. The stabilization problem of the digital fuzzy control system is solved by the linear matrix inequality(LMI) theory. Convex optimization techniques are utilized to find the stable feedback gains and a common positive definite matrix P for the designed fuzzy control system Furthermore, we develop a real-time fuzzy control system for backing up a computer-simulated truck-trailer with the consideration of the computing time-delay. By using the proposed method, we design a DFC which guarantees the stability of the real time digital fuzzy control system in the presence of computing time-delay.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
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• pp.299-302
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• 2003

대용량의 퍼지데이터를 처리하기 위한 퍼지제어 시스템의 가장 큰 과제는 퍼지추론 및 비퍼지화 단계에서의 수행속도의 개선이다. 본 논문에서는 퍼지제어기의 속도 향상을 위해 [0, 1]사이의 실수값을 갖는 퍼지 소속 함수값을 정수형 격자(pixel)에 매핑시켜 정수형 퍼지 소속함수값만을 가지고 퍼지연산을 하는 정수형 퍼지제어기법을 적용한 고속이 정수 연산을 수행하는 퍼지 프로세서와 주변제어 시스템을 FPGA로 설계하여 기존 퍼지제어 시스템에 비해 매우 빠른 실시간 고속퍼지 제어시스템을 구현한다.

• 한국지열·수열에너지학회논문집
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• 제3권2호
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• pp.31-37
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• 2007

The fuzzy control algorithm for HVAC system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with fuzzy control are supply air temperature, chilled water temperature and condenser temperature. This study has been done by using TRNSYS program in order to analyze the HVAC system response. As a result, the fuzzy control algorithm with PID algorithm shows good energy performance in comparison with conventional one.

• 한국정보통신학회논문지
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• 제17권1호
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• pp.8-14
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• 2013

본 논문에서는 친환경 이동 수단인 이륜 역진자 로봇을 기존의 방법보다 더욱 안정적으로 밸런싱 하기 위한 제어시스템을 구현하였다. 먼저 이륜 역진자 로봇의 제어시스템을 퍼지 제어구조로 선택하고, 적절한 소속함수 요소 값들을 지정된 3종류의 무게에 따라 시행착오적으로 구하였다. 임의의 무게에 따른 퍼지 소속 함수 요소 값을 구하기 위해 3종류의 무게에 따른 퍼지 소속함수 요소 값을 신경회로망으로 튜닝한 뒤 퍼지 제어시스템에 적용하여 보다 안정적인 제어가 가능 하도록 제어시스템을 구현하였다. 구현된 제어시스템을 실제 로봇에 적용시켜 본 결과, 기존의 퍼지 제어시스템에 비해서 본 논문에서 제안한 신경회로망으로 튜닝한 퍼지 제어시스템이 보다 우수함을 확인할 수 있었다.

• International Journal of Control, Automation, and Systems
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• 제3권2호
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• pp.217-224
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• 2005

Generally, the underwater flight vehicle (UFV) depth control system operates with the following problems: it is a multi-input multi-output (MIMO) system because the UFV contains both pitch and depth angle variables as well as multiple control planes, it requires robustness because of the possibility that it may encounter uncertainties such as parameter variations and disturbances, it requires a continuous control input because the system that has reduced power consumption and acoustic noise is more practical, and further, it has the speed dependency of controller parameters because the control forces of control planes depend on the operating speed. To solve these problems, an adaptive fuzzy sliding mode controller (AFSMC), which is based on the decomposition method using expert knowledge in the UFV depth control and utilizes a fuzzy basis function expansion (FBFE) and a proportional integral augmented sliding signal, is proposed. To verify the performance of the AFSMC, UFV depth control is performed. Simulation results show that the AFSMC solves all problems experienced in the UFV depth control system online.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2000년도 추계종합학술대회논문집
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• pp.221-224
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• 2000

We consider one of robust controller, fuzzy-sliding mode controller dealing with model uncertainty, simplified representation of nonlinear system, changed parameters of plant. We propose fuzzy-sliding mode algorithm which provides control input that has system states approaching the choosed sliding surface. This fuzzy controller has a rule base to get initial states converged on sliding surface. This algorithm Is applied to a transfer function of DC motor to be modeled simply and do position control of DC motor due to system parameters. We compare fuzzy-sliding mode controller to both sliding mode controller and fuzzy controller to identify roust control.