• Title, Summary, Keyword: nonlinear control

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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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Anti-shock Controller Design for Optical Disk Drive Systems with Nonlinear Controller (광디스크 드라이브 시스템을 위한 비선형 제어기를 이용한 Anti-Shock 제어기 설계)

  • Baek, Jong-Shik;Chung, Chung-Choo
    • Proceedings of the KIEE Conference
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    • pp.675-677
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    • 2004
  • This paper presents a nonlinear controller design for optical disk drive systems to improve anti-shock performance. The nonlinear anti-shock controller is added parallel to the original linear servo control loop. In the previous work, dead-zone nonlinear element is used for nonlinear controller and PID control method is used for linear controller. Although this strategy improves anti-shock performance, it has a narrow stability bound. In this paper, we propose dead-zone with saturation nonlinear element for the nonlinear controller. Since this nonlinear element improves stability margin, we can use higher gain of dead-zone than the controller with dead-zone only. In the linear controller design, we show that lead-lag control has improved stability margin over PID control. Numerical simulation results show that the proposed method can get better performance to the external shock than previously proposed method.

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Adaptive Neural Dynamic Surface Control via H Approach for Nonlinear Flight Systems (비선형 비행 시스템을 위한 H 접근법 기반 적응 신경망 동적 표면 제어)

  • Yoo, Sung-Jin;Choi, Yoon-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.3
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    • pp.254-262
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    • 2008
  • In this paper, we propose an adaptive neural dynamic surface control (DSC) approach with $H_{\infty}$ tracking performance for full dynamics of nonlinear flight systems. It is assumed that the model uncertainties such as structured and unstrutured uncertainties, and external disturbances influence the nonlinear aircraft model. In our control system, self recurrent wavelet neural networks (SRWNNs) are used to compensate the model uncertainties of nonlinear flight systems, and an adaptive DSC technique is extended for the disturbance attenuation of nonlinear flight systems. All weights of SRWNNs are trained on-line by the smooth projection algorithm. From Lyapunov stability theorem, it is shown that $H_{\infty}$ performance nom external disturbances can be obtained. Finally, we present the simulation results for a nonlinear six-degree-of-freedom F-16 aircraft model to confirm the effectiveness of the proposed control system.

A pole assignment control design for single-input double-output nonlinear mechanical systems

  • Kobayashi, Masahito;Tamura, Katsutoshi
    • 제어로봇시스템학회:학술대회논문집
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    • pp.144-149
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    • 1993
  • This paper discusses a design of a nonlinear control for a class of single-input double-output nonlinear mechanical systems. When conventional linearization methods are applied to the mechanical systems, some problems of oscillation and unstable phenomena arise. The proposed nonlinear control system resolves these problems. In this design the eigenvalues of the closed-loop nonlinear system are assigned to desired locations and local asymptotic stability of the closed-loop system. is guaranteed. The design method is applied to an inverted pendulum system with a moving weight mechanism. Experimental results show that the proposed nonlinear controller is more effective for stability than the usual linear controller.

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IMC design for nonlinear plants using multiple models, controllers, and switching (다중 모델, 제어기, 스위칭을 이용한 비선형 플랜트의 IMC 제어기 설계)

  • 오원근;구세완;서병설
    • 제어로봇시스템학회:학술대회논문집
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    • pp.241-244
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    • 1996
  • This paper discusses the general properties and the design procedures of Internal Model Control(IMC) scheme for nonlinear plants. Also we propose new nonlinear IMC(NIMC) design method using linear IMC. Although all IMC controllers can be thought simple 'inverse controller', its nonlinear realization is not easy. Propose NIMC is composed multiple linear models, IMC controllers, and switching scheme. The advantages of this method are we can use simple linear IMC design method and need not nonlinear modelings.

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MODEL PREDICTIVE CONTROL OF NONLINEAR PROCESSES BY USE OF 2ND AND 3RD VOLTERRA KERNEL MODEL

  • Kashiwagi, H.;Rong, L.;Harada, H.;Yamaguchi, T.
    • 제어로봇시스템학회:학술대회논문집
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    • pp.451-454
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    • 1998
  • This paper proposes a new method of Model Predictive Control (MPC) of nonlinear process by us-ing the measured Volterra kernels as the nonlinear model. A nonlinear dynamical process is usually de-scribed as Volterra kernel representation, In the authors' method, a pseudo-random M-sequence is ar plied to the nonlinear process, and its output is measured. Taking the crosscorrelation between the input and output, we obtain the Volterra kernels up to 3rd order which represent the nonlinear characteristics of the process. By using the measured Volterra kernels, we can construct the nonlinear model for MPC. In applying Model Predictive Control to a nonlinear process, the most important thing is, in general, what kind of nonlinear model should be used. The authors used the measured Volterra kernels of up to 3rd order as the process model. The authors have carried out computer simulations and compared the simulation results for the linear model, the nonlinear model up to 2nd Volterra kernel, and the nonlinear model up to 3rd order Vol-terra kernel. The results of computer simulation show that the use of Valterra kernels of up to 3rd order is most effective for Model Predictive Control of nonlinear dynamical processes.

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Development of an Educational System and Real Time Nonlinear Control (I) (교육용 시스템 개발과 실시간 비선형 제어(I))

  • 박성욱
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.12
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    • pp.562-570
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    • 2002
  • The Purpose of this paper is to design and manufacture an educational system in order to demonstrate the causes and effects of electromagnetic induction.'rho educational system described in this study is a "jumping ring apparatus". This system demonstrates the principle of electromagnetic induction, a force from AC sources, Lenz's law of repulsion and transformer. The educational system is composed of a jumping ring apparatus, a sensor array, encoder, A/D converter, D/A converter and nonlinear controller. The educational system is controlled by 586 PC using Turbo C program. The sensor array is composed of 20 optical sensors. The nonlinear controller consists of nonlinear control algorithm and control board included SCR, FET and phase controller. The A/D converter is used to show the height of ring position to analog for an education purpose. The control signal calculated from the nonlinear control of algorithm send control board through 8 bit D/A convertor. Experiment results are given to verify that Proposed nonlinear controller is useful in on line control of the educational system.al system.

Nonlinear Control of Torque and Speed of S.I.Engines Using Electric Throttle Control (트로틀 앵글 제어에 의한 내연기관의 토오크 및 속도의 비선형 제어)

  • 원문철;강병배;박문수;김태영
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.72-81
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    • 1999
  • A nonlinear engine torque and speed control algorithm using throttle angle control is developed with an engine load torque estimation algorithm. Three 3-dimensional nonlinear engine maps as a part of the nonlinear control algorithm are obtained from steady state engine dynamometer tests. An electric throttle actuator is developed using a stepper motor and a 8 bit micro-processor. The speed control and external load estimation algorithm are tested via engine speed control experiments, and show performance good enough for using various engine torque and speed control applications.

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Switching Control for Second Order Nonlinear Systems Using Singular Hyperplanes

  • Yeom Dong-Hae;Choi Jin-Young
    • International Journal of Control, Automation, and Systems
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    • v.4 no.1
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    • pp.124-135
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    • 2006
  • In this paper, we propose a switching control method for a class of 2nd order nonlinear systems with single input. The main idea is to switch the control law before the trajectory of the solution arrives at singular hyperplanes which are defined by the denominator of the control law. The proposed method can handle a class of nonlinear systems which is difficult to be stabilized by the existing methods such as feedback linearization, backstepping, control Lyapunov function, and sliding mode control.

Chaos in PID Controlled Nonlinear Systems

  • Ablay, Gunyaz
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1843-1850
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    • 2015
  • Controlling nonlinear systems with linear feedback control methods can lead to chaotic behaviors. Order increase in system dynamics due to integral control and control parameter variations in PID controlled nonlinear systems are studied for possible chaos regions in the closed-loop system dynamics. The Lur’e form of the feedback systems are analyzed with Routh’s stability criterion and describing function analysis for chaos prediction. Several novel chaotic systems are generated from second-order nonlinear systems including the simplest continuous-time chaotic system. Analytical and numerical results are provided to verify the existence of the chaotic dynamics.