• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.597-602
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• 1987

This paper proposes a voltage-fed high frequency resonant inverter having variable voltage variable frequency(VVVF) control function. VVVF control is performed by PWM-TRC method in the boost type chopper and PFM-TRC method in the high frequency resonant inverter. This circuit is suitable for induction heating and melting power supply in industry. The operating characteristics of this inverter are discussed from a theoretical point of view. The results of operating characteristic analyses are given leading to complete designing data.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.101-102
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• 2006

Similar to Orthogonal Frequency Division Multiplexing (OFDM), a Single Carrier with Frequency Domain Equalization (SC-FDE) system is computationally efficient since equalization is performed on a block of data in the frequency domain. In coherent QAM schemes, the mean phase rotation error caused by the residual carrier frequency offset may lead to serious degradation. When the frequency equalizer is combined with the mean phase error tracking algorithm, its performance can be enhanced noticeably.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.1 s.94
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• pp.191-199
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• 1999

In designing the tracking system of an optical disc drive, it is first necessary to eliminate the undesired influence of any visible mechanical vibrations. In this paper a geometrical method to analyze the frequency response of an elastically supported planar rigid body has been presented. Using the theory of screw, a geometrical expression of a compliant transfer function which describes the effects of the locations of an applied force and observation on the response has been derived. Applying the substructure synthesis method, a technique to stabilize the tracking mechanical system has been presented with a numerical example.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.8 no.3
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• pp.83-90
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• 1983

N-path SC tracking filter is studied beyond the audio frequency range. First, the SC filter Cell which would determine total SC filter characteristics is analyzed by the two methods, charge equation method and difference equation method. Second, 4-path and 8-path SC filter are presented, including only capacitors and switches. Then, 4-path and 8-path SC tracking filter are constructed by conisting of SC filter block and PLL block. In this experiment, maximum response shift is confirmed. With respect to the capacitor ratios and the number of path, Q and Gain(dB) is considered. Also tracking range is measured.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.5
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• pp.76-84
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• 1994

Recently, Optical BJTC as a new approach for real-time multi-target tracking has been intensively studied. But the conventional system has some problems in the practical applications such as the false alarm and target missing and low correlation efficiency, and these poor performances are analyzed to be deeply dependent on the binarization method. So, in this paper, a new BJTC system which has the improved performances in target discrimination and diffraction efficiency is suggested, which is based on the JTPS having the same properties with those of the matched filter and new power spectrum binarization method to use effectively the high frequency components of the JTPS signal. Through the computer simulation and some experiments, the performances of the new BJTC tracking system are analyzed and proved to be superior to those of the conventional system baseds on Median method in multi- target tracking problems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.5
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• pp.1498-1507
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• 1996

This paper presents a robust control of a smart flexible structure featured by a piezofilm actuator characterizing its light weght and quick response time. A mathematical governing equation for the proposed structure is derived by employing Hamilton's principle and a state space control model is subsequentrly obtained through modal analysis. Uncertain system parameters such as frequency variation are included in the control model. A sliding mode control theroy thich has inherent robustness to systme uncertainties is adopted to design a tracking controller for the peizofilm actuator. Using the output informaiton from the tip deflection sensor, a full-order observer is constructed ot estimate state variables for the system. Tracking performances for desired trajectories of sinusoidal amd step functions are evaluated by undertaking both simulation and experimental works.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.3
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• pp.51-55
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• 2006

An adaptive tracking controller is presented for the vibration reduction of flexible manipulator employed in hazardous area by combining input shaping technique with sliding-mode control. The combined approach appears to be robust in the presence of severe disturbance and unknown parameter which will be estimated by least-square method in real time. In a maneuver strategy, it is found that a hybrid trajectory with a combination of low frequency mode and rigid-body mode results in better performance and is more efficient than the traditional rigid body trajectory alone which many researchers have employed. The feasibility of the adaptive tracking control approach is demonstrated by applying it to the simplified model of robot system. For the applications of the proposed technique to realistic systems, several requirements are discussed such as control stability and large system order resulted from finite element modeling.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.3
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• pp.239-244
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• 2010

This paper is to present map building of mobile robot using RFID (Radio Frequency Identification) technology and ultrasonic sensor. For mobile robot to perform map building, the mobile robot needs its localization and accurate driving in space. In this reason, firstly, kinematic modeling of mobile robot under non-holonomic constrains is introduced. Secondly, based on this modeling, a tracking controller is designed for tracking a given path based on backstepping method using Lyapunov function. The Lyapunov function is also introduced for proving the stability of the designed tracking controller. Thirdly, 2D map building is performed by RFID system, mobile robot system and ultrasonic sensors. The RFID mobile robot system is composed of DC motor, encoder, ultra sonic sensor, digital compass, RFID receiver and RFID antenna. Finally, the path tracking simulation results and map building experimental results are presented to show the effectiveness of the designed controller.

• Journal of Power Electronics
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• v.16 no.1
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• pp.277-286
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• 2016

This paper offers two Maximum Power Point Tracking (MPPT) systems for Photovoltaic (PV) applications. The first MPPT method is based on a fixed frequency Model Predictive Control (MPC). The second MPPT technique is based on the Predictive Hysteresis Control (PHC). An experimental demonstration shows that the proposed techniques are fast, accurate and robust in tracking the maximum power under different environmental conditions. A DC/DC converter with a high voltage gain is obligatory to track PV applications at the maximum power and to boost a low voltage to a higher voltage level. For this purpose, a high gain Switched Inductor Quadratic Boost Converter (SIQBC) for PV applications is presented in this paper. The proposed converter has a higher gain than the other transformerless topologies in the literature. It is shown that at a high gain the proposed SIQBC has moderate efficiency.

• Journal of Aerospace System Engineering
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• v.3 no.4
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• pp.35-40
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• 2009

The first purpose of this study is to develop a GCS(Ground Control System) by using RF(Radio Frequency) wireless communication equipments for UAV(Unmanned Aerial Vehicle). The second goal is to develop an antenna tracking system operating automatically. UAV receives flight data from a RF wireless system. So the role of antenna tracking system is very important to keep good communication state between UAV and GCS. GCS can check flight data and display a aviation state of UAV in real-time. The flight data displayed in real-time by GCS include the latitude, longitude, altitude, speed and so on. Experiments that measure a communication range and reliability are needed to develop a RF wireless communication system.