• Title, Summary, Keyword: Nonlinear systems

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Neural model predictive control for nonlinear chemical processes (비선형 화학공정의 신경망 모델예측제어)

  • 송정준;박선원
    • 제어로봇시스템학회:학술대회논문집
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    • pp.490-495
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    • 1992
  • A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming cooperates with neural identification network is used to generate the optimum control law for the complicate continuous/batch chemical reactor systems that have inherent nonlinear dynamics. Based on our approach, we developed a neural model predictive controller(NMPC) which shows excellent performances on nonlinear, model-plant mismatch cases of chemical reactor systems.

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An Approach to a Formal Linearization toy Time-variant Nonlinear Systems using Polynomial Approximations

  • Komatsu, Kazuo;Takata, Hitoshi
    • 제어로봇시스템학회:학술대회논문집
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    • pp.52.2-52
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    • 2002
  • In this paper we consider an approach to a formal linearization for time-variant nonlinear systems. A time-variant nonlinear sysetm is assumed to be described by a time-variant nonlinear differential equation. For this system, we introduce a coordinate transformation function which is composed of the Chebyshev polynomials. Using Chebyshev expansion to the state variable and Laguerre expansion to the time variable, the time-variant nonlinear sysetm is transformed into the time-variant linear one with respect to the above transformation function. As an application, we synthesize a time-variant nonlinear observer. Numerical experiments are included to demonstrate the validity of...

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On time-wise approximate nonlinear observer for sampled-data nonlinear systems (샘플링시간에 대한 근사 샘플치 비선형 관측기)

  • 정선태
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.2
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    • pp.28-36
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    • 1996
  • By utilizing the interinsic structure of the underlying continous-time nonlinear system, one can design an approximate sampled-data observer improved with respect ot the sampling-time for the systems. In this paper, we characterize the conditions for the solvability of the improved approximate sampled-data nonlinear observer design problem. In particular, it is shown that when the dimension of the state space is two, the nonlinear systems for which it is possible ot desing 3rd or higher order approximate sampled-data nonlinear observer are locally state-equivalent to an observable bilinear system. The practical implication is that seeking higher order approximate sampled-data nonlinear observer for nonlinear systems is very restricted.

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Detection and parametric identification of structural nonlinear restoring forces from partial measurements of structural responses

  • Lei, Ying;Hua, Wei;Luo, Sujuan;He, Mingyu
    • Structural Engineering and Mechanics
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    • v.54 no.2
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    • pp.291-304
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    • 2015
  • Compared with the identification of linear structures, it is more challenging to conduct identification of nonlinear structure systems, especially when the locations of structural nonlinearities are not clear in structural systems. Moreover, it is highly desirable to develop methods of parametric identification using partial measurements of structural responses for practical application. To cope with these issues, an identification method is proposed in this paper for the detection and parametric identification of structural nonlinear restoring forces using only partial measurements of structural responses. First, an equivalent linear structural system is proposed for a nonlinear structure and the locations of structural nonlinearities are detected. Then, the parameters of structural nonlinear restoring forces at the locations of identified structural nonlinearities together with the linear part structural parameters are identified by the extended Kalman filter. The proposed method simplifies the identification of nonlinear structures. Numerical examples of the identification of two nonlinear multi-story shear frames and a planar nonlinear truss with different nonlinear models and locations are used to validate the proposed method.

Nonlinear control of an autonomous mobile robot using nonlinear obserbers

  • Ishikawa, Masato;Sampei, Mitsuji
    • 제어로봇시스템학회:학술대회논문집
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    • pp.400-404
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    • 1994
  • In this paper, we will investigate the position estimation problem for autonomous mobile robots. Formulating this as a state estimation problem for nonlinear SISO system, then we will apply several types of nonlinear observers. Simulation results of observer-based navigation control will be also provided.

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Design of observer for a class of Lipschitz nonlinear systems

  • Choi, H.L.;Lim, J.T.
    • 제어로봇시스템학회:학술대회논문집
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    • pp.2099-2101
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    • 2005
  • The problem of observer design for a class of Lipschitz nonlinear systems is considered. We propose a new observer design method which takes into account the structure of perturbed nonlinear terms with a scaling factor ${\epsilon}$. An example is provided to demonstrate the usefulness of our result over the existing method.

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Global Synchronization of Two Different Chaotic Systems via Nonlinear Control

  • Emadzadeh, Amir Abbas;Haeri, Mohammad
    • 제어로봇시스템학회:학술대회논문집
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    • pp.985-989
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    • 2005
  • This paper presents chaos synchronization between two different chaotic systems using nonlinear control method. The proposed technique is applied to achieve chaos synchronization for the Lorenz and Rossler dynamical systems. Numerical simulations are also implemented to verify the results.

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An Observer Design for MIMO Nonlinear Systems and Its Application to Induction Motor (다입력 다출력 비선형 시스템의 관측기 설계 및 인덕션 모터에 응용)

  • Lee, Sung-Ryul
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.1
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    • pp.42-48
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    • 2008
  • This paper presents an observer design method for a special class of multi input multi output(MIMO) nonlinear systems. First, we characterize the class of MIMO nonlinear systems with a block triangular structure. Also, the observability matrices for SISO nonlinear systems are extended to MIMO systems. By using the generalized observability matrices, it is shown that under the boundedness conditions of system state and input, the proposed observer guarantees the local exponential stability of error dynamics. Finally, its application to induction motor is given to verify the proposed method.

Robust Adaptive Output Feedback Control for Nonlinear Systems with Higher Order Relative Degree

  • Michino, Ryuji;Mizumoto, Ikuro;Tao, Yuichi;Iwai, Zenta;Kumon, Makoto
    • 제어로봇시스템학회:학술대회논문집
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    • pp.78-83
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    • 2003
  • In this paper, it is dealt with a controller design problem for nonlinear systems with higher order relative degree. A robust adaptive control for uncertain nonlinear systems with stable zero dynamics will be proposed based on the high-gain adaptive output feedback and backstepping strategies. The proposed method is useful in the case where only the output signal is available.

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A formal linearization of nonlinear systems based on the trigonometric fourier expansion

  • Takata, Hitoshi;Komatsu, Kazuo
    • 제어로봇시스템학회:학술대회논문집
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    • pp.939-942
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    • 1989
  • Most of systems are included nonlinear characteristics in practice. One might be faced with difficulties when problems of nonlinear systems are solved. In this paper we present a formal linearization method of nonlinear systems by using the trigonometric Fourier expansion on the state space considering easy inversion. An error bound, an application, and a compensation of this method are also investigated.

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