• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.338-341
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• 2015

From the past, maglev technique study(mainly for transportation like maglev) has been done. In the domestic, urban maglev train is practical steps now. High-speed maglev train(550km/h) development comes complete, followed by Japan. This year, system of High-speed maglev train(550km/h) is expected to be verified. This paper simulate FEM model for EMS(Electro-Magnetic Suspension) maglev system and verify tendency of reducing disturbance.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.139.2-139
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• 2001

This paper presents identification and control of a surface mounting system. The mount head of the system is modeled to analyze its dynamic characteristics, which is critical to the placement performance of the mounter. Based on this model, an identification work is carried out to estimate the modeled parameters by using genetic algorithm (GA), which plays a role of minimizing an error between the actual response and the model response. Having obtained the identified parameters, we design a disturbance observer control to compensate the friction. The disturbance observer can estimate the friction force and the uncertainty of the system. From the experimental results, it is found that the proposed disturbance observer plus PID controller show a better performance than PID controller alone. In order to accomplish a stable contact content control for fast mounting a ...

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.326.1-326
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• 2002

A fuzzy logic controller design technique is proposed to apply to the control of flexible system under irregular disturbance. The fuzzy rules of $\ulcorner$Mode Selecting Fuzzy Controller$\lrcorner$ are constructed using displacement, velocity information and modal characteristics of the system. The frequency information of flexible system is picked up from $\ulcorner$Mode Selecting Unit$\lrcorner$ based on Fast-Fourier transform algorithm. Experiment is conducted to verify the proposed theoretical approach. (omitted)

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.197-202
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• 1995

When the process disturbance of nuclear power plant occurred, the operator should ensure plant safety, economy and identify the causes of disturbance. To accomplish these goals, operator should process a large amounts of information. Among these, alarms would be often in the operator's first indication of a plant state change or disturbance. To support limited information processing capability of operator, considerable works are under way to develop advanced alarm processing systems and to evaluate it. However, conventional evaluation method could provide just evaluation results but the design alternatives to enhance alarm system performance. To overcome problems associated with conventional evaluation methods of alarm system, signal detection theory(SDT) was introduced, and it was possible conclude that SDT could not only evaluate system but also suggest design alternatives for performance enhancement.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.252-260
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• 1997

In this paper, a friction compensation method using a disturbance observer is proposed for an impedance control of pneumatic manipulator. It is assumed that the generated torque by a pneumatic actuator can be estimated based on the pressure signals and the discharge volume. In order to improve the dynamic characteristics of the pneumatic actuator driven by meter out method, we construct the inner torque control system by feeding back the generated torque. In order to reduce the influence of disturbances comprising friction torque and parameter variations of plant, the impedance control system is constructed with a disturbance observer which estimates the disturbances based on the generated torque of pneumatic actuator, the angular velocity and the reaction torque. From some experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque in the impedance control of a pneumatic manipulator.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.190-190
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• 2000

This paper presents a multirate state feedback control (MRSFC) method for systems sensitive to disturbance and noise based on the multirate estimator design using the current estimator. MRSFC updates the controller output slower than the measurement sampling frequency of system output by a lifting factor R=T$\sub$c//T$\sub$s/. The closed-loop MRSFC system is less sensitive to disturbance and noise due to filtering effect than the conventional single-rate control system. The multirate estimator gain is obtained from solving a conventional pole placement problem such that MRSFC has the same spectrum of eigenvalues in the s-plane as the single-rate control. We applied the proposed multirate state feedback controller to a galvanometer servo system. Simulation and experimental results show that settling and tracking performances are improved compared with a conventional single-rate pole placement control (PPC).

• Transactions of the Society of Information Storage Systems
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• v.3 no.1
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• pp.13-16
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• 2007

The purpose of this paper is real time tilt servo control of the holographic data storage system. Holographic data storage device is a next generation data storage device with high storage density, high transfer rate and short access time. This device is very sensitive to a disturbance due to the enormous storage density. As to the recording material changed disc type, the media continuously vibrates as the disc rotates. When disc rotates, deviation, eccentricity and unbalance disturbance are occurred. This disturbances cause disc tilt, finally reference beam does not illuminates to correct incidence angle. Therefore real time tilt servo control is essential. In this paper, the algorithm is proposed to make real time tilt detection in angle multiplexing of the holographic data storage system with an additional servo beam and the experiments are performed.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.7
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• pp.551-558
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• 2000

In this paper a systematic approach to automatic classificationi of power system harmonic disturbances is proposed where the proposed approach consists of the following three steps:(i) detecting and localizing each harmonic disturbance by applying discrete wavelet transform(DWT) (ii) extracting an efficient feature vector from each detected disturbance waveform by utilizing FFT and principal component analysis (PCA) along with Fisher's criterion and (iii) classifying the corresponding type of each harmonic disturbance by recognizing the pattern of each feature vector. To demonstrate the performance and applicability of the proposed classification procedure some simulation results obtained by analyzing 8-class power system harmonic disturbances being generated with Matlab power system blockset are also provided.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.3
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• pp.286-293
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• 1999

A new control scheme using a torsional torque estimator based on a neural network is proposed and investigated for improving control characteristics of the high-performance motion control system. This control method presents better performance in the corresponding speed vibration response, compared with the disturbance observer-based control method. This result comes from the fact that the proposed neural network estimator keeps the self-learning capability, whereas the disturbance observer-based torque estimator with low pass filter should dbjust the time constant of the adopted filter according to the natural resonance frequency detemined by considering the system parameters varied. The simulation results shows the validity of the proposed control scheme.

• Journal of information and communication convergence engineering
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• v.2 no.1
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• pp.46-51
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• 2004

The problem of reducing the effect of an unknown disturbance on a dynamical system is one of the most fundamental issues in control design. We propose a robust PID (Proportional Integral Derivative) control method with neural network for improving the performance due to the rejection of an unknown disturbance. The proposed system consists of a model of the plant, a conventional PID controller and a multi-layer neural network, and is composed of two loop; the first loop enables the system to achieve stability of system, the second loop rejects an unknown disturbance. Simulation and experiment results show that the proposed method improves considerably on the performance of the conventional PID control method and the typical IMC method using neural network.