• Title/Summary/Keyword: self recurrent wavelet neural network

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Robust Flight Control System Using Neural Networks: Dynamic Surface Design Approach (신경 회로망을 이용한 강인 비행 제어 시스템: 동적 표면 설계 접근)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.55 no.12
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    • pp.518-525
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    • 2006
  • This paper presents the adaptive robust control method for the flight control systems with model uncertainties. The proposed control system can be composed simply by a combination of the adaptive dynamic surface control (DSC) technique and the self recurrent wavelet neural network (SRWNN). The adaptive DSC technique provides us with the ability to overcome the 'explosion of complexity' problem of the backstepping controller. The SRWNNs are used to observe the arbitrary model uncertainties of flight systems, and all their weights are trained on-line. From the Lyapunov stability analysis, their adaptation laws are induced and the uniformly ultimately boundedness of all signals in a closed-loop adaptive system is proved. Finally, simulation results for a high performance aircraft (F-16) are utilized to validate the good tracking performance and robustness of the proposed control system.

Intelligent Sliding Mode Control for Robots Systems with Model Uncertainties (모델 불확실성을 가지는 로봇 시스템을 위한 지능형 슬라이딩 모드 제어)

  • Yoo, Sung-Jin;Choi, Yoon-Ho;Park, Jin-Bae
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.10
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    • pp.1014-1021
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    • 2008
  • This paper proposes an intelligent sliding mode control method for robotic systems with the unknown bound of model uncertainties. In our control structure, the unknown bound of model uncertainties is used as the gain of the sliding controller. Then, we employ the function approximation technique to estimate the unknown nonlinear function including the width of boundary layer and the uncertainty bound of robotic systems. The adaptation laws for all parameters of the self-recurrent wavelet neural network and those for the reconstruction error compensator are derived from the Lyapunov stability theorem, which are used for an on-line control of robotic systems with model uncertainties and external disturbances. Accordingly, the proposed method can not only overcome the chattering phenomenon in the control effort but also have the robustness regardless of model uncertainties and external disturbances. Finally, simulation results for the five-link biped robot are included to illustrate the effectiveness of the proposed method.

Formation Control for Underactuated Autonomous Underwater Vehicles Using the Approach Angle

  • Kim, Kyoung Joo;Park, Jin Bae;Choi, Yoon Ho
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.13 no.3
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    • pp.154-163
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    • 2013
  • In this paper, we propose a formation control algorithm for underactuated autonomous underwater vehicles (AUVs) with parametric uncertainties using the approach angle. The approach angle is used to solve the underactuated problem for AUVs, and the leader-follower strategy is used for the formation control. The proposed controller considers the nonzero off-diagonal terms of the mass matrix of the AUV model and the associated parametric uncertainties. Using the state transformation, the mass matrix, which has nonzero off-diagonal terms, is transformed into a diagonal matrix to simplify designing the control. To deal with the parametric uncertainties of the AUV model, a self-recurrent wavelet neural network is used. The proposed formation controller is designed based on the dynamic surface control technique. Some simulation results are presented to demonstrate the performance of the proposed control method.