• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.526-529
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• 1998

In this paper, we proposed a nonlinear sliding mode controller to regulate the swinging angle of Overhead Crane System. Roughly speaking, the controller is designed to regulate an output(the swing angle) while providing internal stability. It is difficult to apply many of standard nonlinear control design techniques. In contrast to control that use a command generator and possibly a time-varying feedback, our control law is simple autonomous nonlinear controller. We analyze the stability of the closed-loop system using an $L_2$ Sliding surface conditions approach on a nonlinear feedback linearization of the system about the desired periodic orbit. One can easily extend this approach to analyze the robustness of the control system with respect to disturbances and parameter variations.

• Tribology and Lubricants
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• v.27 no.3
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• pp.147-155
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• 2011

The ceramic coatings are excellent materials of cutting tools and sliding parts. To evaluate the wear characteristics of very thin ceramic coated layer, it is very important to investigate its wear process microscopically. An effective method for investigating the wear of a thin layer is the observation of wear process in microscopic detail using in-situ system. In this study, using the SEM Tribosystem as in-situ system, the microscopic wear mode of TiN coatings was investigated in repeated sliding. As results, four modes were observed for TiN coatings: Ploughing, powder formation, flake formation and coating delimitation. The observation of the microscopic wear by in-situ system can clarify the allowable stress of TiN coating.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2064-2066
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• 2003

In this paper, an observer with novel sliding mode is proposed. The sliding mode is designed by defining a extended state whose dynamic is determined from the output error. It has the advantage of giving the desired dynamics for the error system. To get the exact system parameter for an observer, the RLS algorithm is used.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.65-68
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• 1988

In this paper the application of variable structure control with sliding modes for improving the dynamic response and eliminating chattering of DC servo motor drive is presented. Sliding mode control is an effective means to keep a system insensitive to parameter variation and disturbances. In this method the control structure is changed discontinuously to farce the system dynamic to follow a predetermined trajectory. However the discontinuous change in control structure causes the controller input to chatter and gives non-zero steady state error. To overcome this problem, the discontinuous sign function is replaced by a proper continuous function, and presented through experiment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.349-354
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• 2011

This paper addresses the trajectory tracking problem for ship berthing using sliding mode technique. With significant potential advantages: insensitivity to plant nonlinearities, parameter variations, remarkable stability and performance robustness with environmental disturbances, the multivariable sliding modes controller is proposed for solving trajectory tracking of ship in harbor area. In this study, the ship position and heading angle are simultaneously tracked to guarantees that the ship follows a given path (geometric task) with desired velocities (dynamic task). The stability of the proposed control law is proved based on Lyapunov theory. The proposed approach has been simulated on a computer model of a supply vessel with good results.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.340-342
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• 2005

A sliding mode controller for the grid-connected photovoltaic system has been presented. This controller is constructed from the time-varying sliding surface In order to control the sinusoidal inductor current and solar array power simultaneously. The proposed controller can achieve the tight regulation of current and power under the parameter variation environment.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.2
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• pp.163-172
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• 2010

A robust positioning control system has been studied using a friction parameter observer and a recurrent fuzzy neural network based on the sliding model. To estimate a nonlinear friction parameters of the LuGre friction model, a dual friction model-based observer is introduced. In addition, an approximating method for a system uncertainty has been developed using a recurrent fuzzy neural network technique to improve positioning performance. Experimental results have been presented to validate the performance of a proposed intelligent compensation scheme.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.994-996
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• 1998

In this paper, the standard Dole, Glover, Khargoneker, and Francis (abbr. : DGKF 1989) $H_{\infty}$ controller $(H_{\infty}C)$ is extended to the nonlinear feedback linearization-$H_\infty$-based sliding mode controller (NFL-$H_\infty$-based SMC). A stability proof of the closed-loop stability is done by a Lyapunov function candidate using an addition form of the sliding surface vector and the estimation error.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.39-44
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• 2005

To validate the rotor performance analysis, 3D Computational Fluid Dynamics(CFD) analysis was performed for tilt rotor aeroacoustic model(TRAM). Also, 3D vehicle with rotating rotors was simulated for rotor power effect analysis. Multiple reference frame(MRF) and sliding mesh techniques were implemented to capture the effect of rotor revolution. CFD results were compared with the wind tunnel test results to validate their accuracy. At helicopter mode, CFD analysis predicted lower thrust than the wind tunnel test but CFD results showed good agreement with the test result at cruise mode. Rotor power effect decreased the lift but did not change drag and pitching moment.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.982-984
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• 1998

In this paper, a stability proof of the closed-loop stability for the nonlinear feedback linearization-$H_\infty$/sliding mode controller (NFL-$H_\infty$/SMC) is done by a Lyapunov function candidate using an addition form of the sliding surface vector and the estimation error.