• Journal of IKEEE
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• v.11 no.4
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• pp.213-218
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• 2007

We consider a web transport system. The objective of this paper is to design the output feedback controller such that the controller can track a desired tension and processing speed on web transport system. We propose the new design method using observer and feedback linearization technique. The proposed method use a nonlinear feedback to transform to linear system and high gain observer to estimate the state value. We show that the proposed controller can achieve the control object using only output. We show a performance of controller via the simulation.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.183-185
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• 2006

This paper presents a SISO nonlinear controller for the power system consisting of a synchronous generator connected to an infinite bus. The proposed controller is based on input-output feedback linearization, with a modified version of the terminal voltage equation used as the output. The resulting closed-loop has no internal dynamics, and thus stability is guaranteed. The controller performance is seen to be effective through simulations.

• Journal of Power System Engineering
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• v.6 no.3
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• pp.49-56
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• 2002

This study suggests a trajectory tracking controller composed of an input output linearization compensator and a linear controller. The input output linearization compensator is derived from the nonlinear equations of a pneumatic control system and it algebraically transforms a nonlinear system dynamics into a linear one, so that input output characteristics of the control system is linearized regardless of the variation of the operating point and linear control techniques can be applied. The results of nonlinear simulations show that the proposed controller tracks the given trajectories more accurately than a state feedback controller does.

• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.157-178
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• 2001

In this paper, the nonlinear control of high precision pointing stabilization system using feedback-linearization design methodology based on system parameter identification is discussed. Modern nonlinear servomechanism theory is adapted to cope with the hard nonlinearities inherent in the turret system. The mathematical models of electrical turret driving system to develop a high performance control algorithm are derived, and the parameter estimation algorithm identifying the unknown system parameters such as vicious and coulomb frictions, stiffness and inertia is developed. Through computer simulation and experiments, it is shown that pointing and tracking accuracy and stabilization against the wideband stochastic disturbance induced by vehicle running on the bump course are improved. Therefore, it is considered the proposed nonlinear control technique is effective in counteracting the nonlinearities and disturbances.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1496-1499
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• 1996

A nonlinear tracking control technique developed for the control of nonlinear systems has been applied to the autopilot design of missile system. The difficulties in the application of inversion based control methods such as input-output feedback linearization and sliding mode control due to nonminimum phase characteristics are discussed. To avoid the stability problem associated with unstable zero dynamics, the input-output feedback linearization is applied with output-redefinition method to normal acceleration control. The output-redefinition method gives an indirect way to apply the nonlinear controls to nonminimum phase plants by redefining the plant output such that the tracking control of the modified output ensures the asymptotic tracking of the original output. The numerical simulation shows satisfactory results both for nominal and for slightly perturbed missile systems adopting the sliding mode control technique. However, the robustness problem in this method is briefly investigated and verified with the simulation.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.1
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• pp.30-39
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• 2000

In order to linearize the nonlinear systems, two different methods(i.e. state coordinate change and feedback) are usually used. In this paper, we consider the multi-input discrete-time nonlinear systems and obtain the necessary and sufficient conditions for both the linearization problem by state-coordinate change and the feedback linearization problem. The way of finding state coordinate change and state feedback which linearize the given system is also given in the proof.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.131-138
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• 2007

In this paper, a novel nonlinear control method of the CVCF(constant voltage and constant frequency) output voltage for the three-phase PWM inverter with LC output filters is proposed. A nonlinear modeling including the output LC filters is linearized by feedback linearization theory, the controllers of which can be designed based on a linear control theory. It is applied to the DC/AC power conversion of the PWM inverter for stand-alone wind power generation system. It has been verified by the experimental results that the proposed control scheme gives high dynamic responses at load variation as well as a zero steady-state error.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1134-1136
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• 1996

A necessary and suficient conditions is proposed for feedback linearizable SISO systems with unknown constant parameters. It is shown that the systems which satisfy the proposed conditions can be transformed into a controllable linear system with unknown parameter and it can be stabilized using the nonlinear feedback linearizing controller. We also present the analysis and implementation of a nonlinear feedback linearizing control for an Electro-Magnetic Suspension (EMS) system. We show that an EMS system is nonlinear feedback linearizable and satisfies the proposed conditions, and hence that the proposed nonlinear feedback controller for an EMS system is robust against mass parameter perturbation and force disturbance.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1650-1651
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• 2007

This paper presents a novel nonlinear speed control strategy for induction motor utilizing exact feedback linearization with states feedback. The speed and flux control loops utilize nonlinear feedback which eliminates the need for tuning, while ordinary proportional-integral controllers are used to control the stator current of d-axis the speed. The control scheme is derived in rotor field coordinates and employs an appropriate estimator for estimation of the rotor flux angle, flux magnitude.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.474-477
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• 1995

In this paper, the nonlinear model of axial electro-magnetic suspension(EMS) system is presented. The characteristic of attracyion force is analyzed by FEM. Some simulation is given to compare the sliding mode control based on the input-output linearization with the classical linear control using Taylor approximation. Real result of regulating control, transient response comparison, and robustness control with disturbance using the sliding mode method is presented.