• International Journal of Fuzzy Logic and Intelligent Systems
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• 제3권1호
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• pp.58-65
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• 2003

In this paper, a new model, which is a Takagi-Sugeno fuzzy model, for mobile robot is presented. A controller, consisting of two loops the one of which is the inner state feedback loop designed for stability and the outer loop is a PI controller designed for tracking the reference input, is suggested. Because the robot dynamics is nonlinear, it requires the controller to be insensitive to the nonlinear term. To achieve this objective, the model is developed by well known T-S fuzzy model. The design algorithm of inner state-feedback loop is regional pole-placement. In this paper, regions, for which poles of the inner state feedback loop are lie in, are formulated by LMI's. By solving these LMI's, we can obtain the state feedback gains for T-S fuzzy system. And this paper shows that the PI controller is equivalent to the state feedback and the cost function for reference tracking is equivalent to the LQ(linear quadratic) cost. By using these properties, it is also shown in this paper that the PI controller can be obtained by solving the LQ problem.

• Advances in aircraft and spacecraft science
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• 제8권1호
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• pp.69-85
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• 2021

A modified fuzzy mechanical control of large-scale multiple time delayed dynamic systems in states is considered in this paper. To do this, at the first level, a two-step strategy is proposed to divide a large system into several interconnected subsystems. As a modified fuzzy control command, the next was received as feedback theory based on the energetic function and the LMI optimal stability criteria which allow researchers to solve this problem and have the whole system in asymptotically stability. Modeling the Fisher equation and the temperature gauge for high-speed aircraft and spacecraft shows that the calculation method is efficient.

• 한국지능시스템학회논문지
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• 제21권3호
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• pp.302-306
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• 2011

본 논문은 무인 잠수정(Autonomous underwater vehicles: AUVs)의 심도 제어를 위한 타카키-수게노 (Takagi-Sugeno: T-S) 퍼지 모델 기반 제어기를 제안한다. Sector nonlinearity 기법을 통해 주어진 비선형 무인 잠수정은 T-S 퍼지 모델로 표현된다. 리아푸노프(Lyapunov) 함수를 이용하여 무인 잠수정의 심도 제어 성능을 보장하는 선형 행렬 부등식(Linear matrix inequality: LMI) 형태의 제어기 설계 조건을 유도한다. 모의 실험을 통해 제안된 기법의 심도 제어 성능을 검증한다.

• 제어로봇시스템학회논문지
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• 제9권5호
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• pp.374-378
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• 2003

A new discrete-time fuzzy output feedback control method for nonlinear systems with unknown time-delay is proposed. Ma et al. proposed an analysis and design method of fuzzy controller and observer and Cao et al. extend this result to be applicable fir the nonlinear systems with known time-delay. For the case of unknown time-delay, we derive the sufficient condition f3r the asymptotic stability of the equilibrium Point by applying Lyapunov-Krasovskii theorem and convert this condition into the LMI problem.

• 대한전기학회논문지:시스템및제어부문D
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• 제49권2호
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• pp.68-73
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• 2000

This paper addresses the analysis and design of fuzzy control systems for a class of complex nonlinear systems. Firstly, the nonlinear system is represented by Takagi-Sugeno(TS) fuzzy model and the global controller is constructed by compensating each linear model in the rule of TS fuzzy model. The design of conventional TS fuzzy-model-based controller is composed of two processes. One is to determine the static state feedback gain of each local model and the other is to validate the stability of the designed fuzzy controller. In this paper, we propose an alternative methods for the design of TS fuzzy-model-based controller. The design scheme is based on the extension of conventional optimal control theory to the design of TS fuzzy-model-based controller. By using the proposed method, the design and stability analysis of the TS fuzzy model-based controller is reduced to the problem of finding the solution of a set of algebraic Riccati equations. And we use the recently developed interior point method to find the solution of AREs, where AREs are recast as the LMI formulation. A numerical simulation example is given to show the effectiveness and feasibiltiy of the proposed fuzzy controller design method.

• 제어로봇시스템학회논문지
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• 제17권9호
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• pp.851-856
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• 2011

In this paper, the fuzzy output-feedback controller is addressed for a discrete-time nonlinear interconnected systems with common input. The nonlinear interconnected system is represented by a T-S (Takagi-Sugeno) fuzzy model. Based on T-S fuzzy interconnected system, the fuzzy output-feedback controller is designed with common input. The stability condition of the closed-loop system is represented to the LMI (Linear Matrix Inequality) form. PEMFC model is given to show the verification of the controller discussed throughout the paper.

• 한국정보통신학회논문지
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• 제17권6호
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• pp.1399-1408
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• 2013

본 논문은 유도전동기의 제어에 있어서 성능향상을 위하여 가중치를 도입한 새로운 적분제어기법을 제안하여 $H_{\infty}$ T-S 퍼지제어기와 함께 사용하였다. $H_{\infty}$ T-S퍼지제어기는 유도전동기의 비선형성과 강인성을 위하여 사용되었고 가중치를 도입한 적분제어기는 추적문제를 조정기문제로 바꾸어 줌과 동시에 제어성능을 향상시키기 위해서 사용되었다. $H_{\infty}$ T-S퍼지제어기는 국부선형모델을 기반으로 구해지는 국부선형제어기 들의 선형결합으로 구성되며 각각의 국부 선형제어이득들은 LMI(Linear Matrix Inequlity)를 이용하여 계산된다. 본 논문에서는 가중치에 따라 결정되는 다양한 LMI해의 선택을 가능하게 함으로써 제어성능을 향상시켰다.

• 조명전기설비학회논문지
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• 제24권10호
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• pp.26-32
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• 2010

This paper proposes a new load torque observer based on the Takagi-Sugeno fuzzy method for a permanent magnet synchronous motor(PMSM). A Linear Matrix Inequality(LMI) parameterization of the fuzzy observer gain is given, and the LMI conditions are derived for the existence of the fuzzy load torque observer guaranteeing $\alpha$-stability and linear quadratic performance. In this paper, a nonlinear speed controller is employed to validate the performance of the proposed fuzzy load torque observer, and various simulation results are presented under motor parameter and load torque variations.

• 전력전자학회논문지
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• 제16권1호
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• pp.1-10
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• 2011

본 논문에서는 영구자석 동기전동기(PMSM)의 강인한 속도 제어를 위하여 퍼지 부하 토크관측기와 퍼지 속도제어기를 제안한다. 또한, 퍼지 부하 토크관측기와 퍼지 속도제어기가 존재하기 위한 LMI 조건을 유도하고, 관측기 및 제어기의 이득을 계산한다. 제안된 제어시스템의 안정도가 보장됨을 해석적으로 증명한다. 본 연구에서 제안된 관측기 기반의 퍼지 속도제어기의 성능을 검증하기 위하여, 시뮬레이션 및 실험 결과가 주어졌다. 본 결과를 통하여 제안된 제어 알고리즘은 영구자석 동기전동기의 속도를 정확하게 제어할 수 있음을 검증하였다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2006년도 추계학술대회 학술발표 논문집 제16권 제2호
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• pp.293-296
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• 2006

This paper presents new sufficient conditions to an intelligent digital redesign (IDR). The purpose of the IDR is to effectively convert an existing continuous-time fuzzy controller to an equivalent sampled-data fuzzy controller in the sense of the state-matching. The state-matching error between the closed-loop trajectories is carefully analyzed using the integral quadratic functional approach. The problem of designing the sampled-data fuzzy controller to minimize the state-matching error as well as to guarantee the stability is formulated and solved as the convex optimization problem with linear matrix inequality (LMI) constraints.