• Journal of Institute of Control, Robotics and Systems
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• v.17 no.1
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• pp.54-60
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• 2011

The flight control law designed for prototype aircraft often leads to degraded stability and performance, although developed control law verify by non-real time simulation and pilot based evaluations. Therefore, the proper evaluation methods should be applied such that flight control law designed can be verified in real flight environment. The one proposed in this paper is IFS (In-Flight Simulator). Currently, this system has been implemented into the F-18 HARV (High Angle of Attack Research Vehicle), SU-27 and F-16 VISTA (Variable stability In flight Simulation Test Aircraft) programs. The IFS necessary switching control law such as fader logic and integrator stand-by mode to reduce abrupt transient and minimize the integrator effect for each flight control laws switching. This paper addresses the concept of switching mechanism with fader logic of "TFS (Transient Free Switch)" and stand-by mode of "feedback type" based on SSWM (Software Switching Mechanism). And the result of real-time pilot evaluation reveals that the aircraft is stable for inter-conversion of flight control laws and transient response is minimized.

• Journal of Electrical Engineering and Technology
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• v.11 no.5
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• pp.1179-1189
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• 2016

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.4
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• pp.165-173
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• 2002

The goal of this paper is optimal switching angle of switched reluctance motor drive system fur maximum energy ratio. A new magnetizing method with a low-frequency increasing the energy conversion ratio that is related to the efficiency of motor is proposed. As the results, it improved the efficiency about 2[%]. And a torque ripple is also sufficiently reduced compared with that of the conventional approach. In order tn start softly regardless of large ripple torque, the profile of phase current is predicted by the ANFIS, and current control mode was adapted when it is operated under the starting speed. Variable implementations en the fields will guarantee the more practical drive system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.511-513
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• 2004

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position, because the position of rotor is an essential information. In the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.6
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• pp.506-513
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• 2001

The torque of an SRM depends on the phase current and derivative of inductance. But an SRM is difficult to control the desired torques because of saturation in magnetic circuit An SRM is controlled by parameters of input voltage, and switch on , off angle The switch on off angles of an SRM regulate the magnitude and shape of current waveform and decide the magnitude and shape of torque This paper proposes an the optimization control scheme by adjusting both the switch on an switch off angle . The switch off angles are decided by reference of efficiency using simulation and experiments. The switch on angles are decided by load torque , And the dwell angles are controlled for torque control and speed control using GA-neural network which is used to simulated the reasonable switching angle.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.108-118
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• 2017

In this paper, the path tracking controller for a surface vessel based on the sliding mode control (SMC) with the switching law is proposed. In order to have no restriction on movement and improved tracking performance, the proposed control system is developed as follows: First, the kinematic and dynamic models in Cartesian coordinates are considered to solve the singularity problem at the origin. Second, the new multiple sliding surfaces are designed with the SMC and approach angle concept to solve the under-actuated property. Third, the switching control system is designed to improve tracking performance. To prove the stability of the proposed switching system under the arbitrary switching, the Lyapunov stability analysis method with the common Lyapunov function is used. Finally, the computer simulations are performed to demonstrate the performance, effectiveness and stability of the proposed tracking controller of a surface vessel.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.9-11
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• 1994

This paper describes an adjustable switching angle control method of Switched Reluctance Motor to improve the drive efficiency when variable loads applied. The control method to build-up optimal current shape is intended to improve the efficiency of SRM over the wide range of output power without requiring additional power devices, which gives more economic benefits compared with any other control methods.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.399-402
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• 2007

We propose a method to achieve both wide viewing angle (WVA) and narrow viewing angle (NVA) characteristics with a single liquid crystal (LC) panel and a single backlight system by using 3-terminal electrode structure. We could control the viewing angle of a single LC cell by using the horizontal or vertical alignment of LC for the dark state at the front.

• Journal of Power Electronics
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• v.19 no.5
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• pp.1235-1247
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• 2019

Zero-Voltage-Switching (ZVS) operation for a Wireless Power Transfer (WPT) system can be achieved by designing a ZVS controller. However, the performance of the controller in some industrial applications needs to be designed tightly. This paper introduces a ZVS controller design method for WPT systems. The parameters of the controller are designed according to the desired performance based on the closed loop dominant pole placement method. To describe the dynamic characteristics of the system ZVS angle, a nonlinear dynamic model is deduced and linearized using the small signal linearization method. By analyzing the zero-pole distribution, a low-order equivalent model that facilitates the controller design is obtained. The parameters of the controller are designed by calculating the time constant of the closed-loop dominant poles. A prototype of a WPT system with the designed controller and a five-stage multistage series variable capacitor (MSVC) is built and tested to verify the performance of the controller. The recorded response curves and waveforms show that the designed controller can maintain the ZVS angle at the reference angle with satisfactory control performance.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.3
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• pp.190-198
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• 2018

This paper proposes a nonisolated, bidirectional, soft-switching DC - DC converter with PWM plus phase shift (PPS) control. The proposed converter has an input-parallel/output-series configuration and can achieve the interleaving effect and high voltage gains, resulting in decreased voltage ratings in all related devices. The proposed converter can operate under zero-voltage switching (ZVS) conditions for all switches in continuous conduction mode. The power flow of the proposed converter can be controlled by changing the phase shift angle, and the duty is controlled to balance the voltage of four high voltage side capacitors. The PPS control device of the proposed converter is simple in structure and presents symmetrical switching patterns under a bidirectional power flow. The PPS control also ensures ZVS during charging and discharging at all loads and equalizes the voltage ratings of the output capacitors and switches. To verify the validity of the proposed converter, an experimental investigation of a 2 kW prototype is performed in both charging and discharging modes under different load conditions and a bidirectional power flow.