• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.329-332
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• 1997

This paper deals with the attitude control problem of nonlinear MIMO propeller setup. Multivariable GPC[Generalized Predictive Control] is adopted as the main controller, and it is implemented by TMS320C31 in the current paper. The main object of control is to move the propellers to wanted positions. System identification is performed to configure the system. Performance of the multivariable predictive controller implemented is shown via some experiments, which shows the controller meets the adequate control purpose.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.935-940
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• 2005

In this paper, dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor bearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation method effectively attenuates the rotor vibration all over the operating range of rotational speed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.9 s.102
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• pp.1045-1052
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• 2005

Tn this paper. dual rotor disk configuration with a coreless stator is proposed for the Lorentz force type integrated motor hearing system. An experimental compensation for the effects of high order harmonics is performed using the digital controller of the experimental setup. The runout profile and rotor unbalance are also identified by the extended influence coefficient method. The experimental results confirm that this compensation scheme effectively attenuates the rotor vibration all over the operating range of rotational speed.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.2
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• pp.136-144
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• 1999

This paper deals with the fault detection problem in uncertain linear multivariable systems and its application. A robust fault detection method presented by Kim et a. (1998) for MIMO (Multi Input/Multi Output) systems has been adopted and applied to the twin rotor MIMO experimental setup using industrial DSP. The system identification problem is formulated for the twin rotor MIMO system and its parameters are estimated using experimental data. Based on the estimated parameters, some fault detection simulations are performed using the robust fault detection method, which shows that the preformance is satisfied.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.6
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• pp.556-564
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• 2013

This paper proposes an initial rotor position detecting algorithm of a PM synchronous motor using an incremental encoder. The proposed algorithm estimates the phase offset between the rotor magnetic flux and the Z-pulse of the incremental encoder by applying six aligning mode current control. The absolute rotor position for driving a PM synchronous motor is calculated by using the phase offset of the Z pulse and A, B pulse signals of the encoder. The PMSM drives based on the estimated rotor position is applied to the elevator door system. The door length is measured on line at first setup of the elevator. The speed control for open, close, and reopen of the elevator door is also presented and the proposed algorithm for the elevator door system is verified by experiment.

• Journal of Power Electronics
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• v.14 no.6
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• pp.1243-1253
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• 2014

The phase inductance of a switch reluctance motor (SRM) is significantly nonlinear. With different saturation conditions, the phase inductance shape is clearly changed. This study focuses on the relationship between coefficient and current in an inductance model with ignored harmonics above the order of 3. A position estimation method based on the variable coefficient inductance model is proposed in this paper. A four-quadrant sensorless control system of the SRM drive is constructed based on the relationship between variable coefficient inductance and rotor position. The proposed algorithms are implemented in an experimental SRM test setup. Experimental results show that the proposed method estimates position accurately in operating two/four-quadrants. The entire system also has good static and dynamic performance.

• The KSFM Journal of Fluid Machinery
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• v.7 no.2 s.23
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• pp.41-49
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• 2004

Condition monitoring is very important in turbo machinery because single failure could cause critical damages to its plant. So, automatic fault recognition has been one of the main research topics in condition monitoring area. We have used a relatively new fault recognition method, Hidden Markov Model(HMM), for mechanical system. It has been widely used in speech recognition, however, its application to fault recognition of mechanical signal has been very limited despite its good potential. In this paper, discrete HMM(DHMM) was used to recognize the faults of rotor system to study its fault recognition ability. We set up a rotor kit under unbalance and oil whirl conditions and sampled vibration signals of two failure conditions. DHMMS of each failure condition were trained using sampled signals. Next, we changed the setup and the rotating speed of the rotor kit. We sampled vibration signals and each DHMM was applied to these sampled data. It was found that DHMMs trained by data of one rotating speed have shown good fault recognition ability in spite of lack of training data, but DHMMs trained by data of four different rotating speeds have shown better robustness.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.458-459
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• 2009

This global case study pursues diversification and intensification for an application system of the national wind map which has been developed to support national strategy building and promotion of wind energy dissemination. We chose nine counties' national wind maps and compared their map area, extraction height, temporal and spatial resolution, download services, etc. to derive a best practice for the Korea wind map application system. Therefore, the application system are designed to offer high resolution height information of which covers wind turbine rotor sweeping area and time-series dataset which can be downloaded for further analysis by users. It is anticipated that the system would contribute greatly to wind energy policy, business and research sectors once the derived ideas have been implemented to the application system

• Tribology and Lubricants
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• v.17 no.3
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• pp.244-250
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• 2001

A rotating axis diagnostic system supported with journal bearing has been established that has been widely used in the industry. In order to measure the most sensitive signals that would be generated in the abnormal operation, sensors which measure AE(acoustic emission), gap and acceleration have been attached at the various location on the experimental apparatus. Data were obtained in the steady state operational condition of the system which was verified through the empirical measurement. Notable discrepancies were observed in RMS acceleration signal which could be utilized to predict the undesirable operational condition of the system.

• New & Renewable Energy
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• v.5 no.4
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• pp.3-8
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• 2009

This global case study pursues diversification and intensification for an application system of the national wind atlas which has been developed to support national strategy building and promotion of wind energy dissemination. We chose nine counties' national wind atlas and compared their map area, extraction height, temporal and spatial resolutions, download services, etc. to derive a best practice for the Korea wind atlas application system. Therefore, the web service content is designed to offer high-resolution height information of which covers wind turbine rotor sweeping area and time-series dataset which can be downloaded for further analysis by users. It is anticipated that the system and web service would contribute greatly to wind energy policy making, business and research sectors.