• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.1912-1921
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• 1999

The equipments mounted on guided-missile undertake heavy vibrational disturbance. Sometimes the equipments mounted on guided-missile go wrong so that the guided-missile flies over unintended place. For the vibration isolation of the equipments mounted on guided-missile, active vibration control was performed. In the case of active vibration technique, the stiffness matrix and the mass matrix are derived based on FEM (ANSYS5.0). Model reduction was carried out and, as a result, we got 7 DOF mass and stiffness matrix. For the sake of FEM model identification, modal experiment was carried out. With the help of Sensitivity Analysis, the natural frequencies of FEM were tuned to those of Experiment. In this work, the Sky Hook and the LQG control theory were adopted for v iteration control using stacked piezoactuator. Experiments were performed with changing excitation frequency from 10 Hz upto 200 Hz and we got frequency response function of guided-missile equipments. The magnitude of 3rd mode of guided-missile equipments is 8.6 % that of Uncontrolled in Skyhook controller and is 3.4 % that of uncontrolled in LQG controller.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.12a
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• pp.209-212
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• 2000

This paper describes the design and implementation of a hard- wired AGV controller using CPLD(Complex Programmable Logic Device). The proposed controller manages a guidance equipment, motor and I/O sequence controller for a self-control traveling. Compared with a conventional $\mu$-processor, the CPLD controller using a hard-wired control method can reduce a difficult programming process. Also, the total costs of production are reduced, such as development time, product's size and difficulty because memory, combinational logic and sequential logics are implemented by CPLD. The Controller designed using behavioral description method with VHDL and was synthesized by MAX＋Plus II of the ALTERA co. We implemented controller using EPF10K10LC84-4 device.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.9
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• pp.698-706
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• 2017

The risk of high power electromagnetic(HPEM) pulse exposure to the devices used in digital control system such as PLC(programmable logic controller) and communication cable is increasing. In this paper, two different frequency ranges HPEMs were exposed to those control systems to assess the each vulnerability. The vulnerability of the EUTs exposed from HPEM were analyzed and compared with a variation of distances and source power. As the EUTs were exposed to higher level of HPEM, the voltage and communication waveform of the control system had shown a distorted response. And the unshielded twisted pair(UTP) cable connected to the EUTs showed operation failures with induced voltage. However, the foiled twisted pair(FTP) cable shielded the connected device efficiently from the HPEM exposure. Therefore, the necessity of the protection measures against the vulnerability of HPEM exposure for the digital control system used in power facilities and industrial site were verified.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.547-557
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• 2020

In this study, damping control devices were applied to the suspension system of a capsule train, and the effects were investigated to improve the ride comfort. The superconductor electrodynamic suspension (SC-EDS) method is used for the capsule train levitation. This method has advantages such as no gap control and a large gap. However, the SC-EDS method has disadvantages such as large gap variation and small damping characteristics against outer vibration, which causes degradation of the ride comfort. In this study, the damping control devices in the primary and secondary suspension were considered to improve the ride comfort in the capsule train. Damping control devices in the primary and secondary suspension can reduce the vibration transmission from outer disturbances to the bogie and from the bogie to the car body, respectively. Simulations for dynamic characteristics analyses were conducted based on the capsule train dynamic model to investigate the effects of the damping control devices on the ride comfort. As a result, it was confirmed that the ride comfort requirements according to the ISO standard can be satisfied by applying the damping control in the capsule train suspension.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.429-430
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• 2016

농업용 하우스의 온방장치로 기존의 경유식 온풍기 구조에서 전기식 온풍기 구조로 바뀌고 있으며, 전기식 온풍기의 경우 멸균을 겸하는 고주파 유도가열 온풍기 적용에 대한 연구가 활발히 진행되고 있다. 본 논문에서는 자동공진 추정기법을 이용한 정격 시 공진형 영전류 스위칭 방식이 이루어질 수 있고, 온풍기 특성에 맞는 새로운 주파수제어 영역을 사용하여 제어하였다. 또한 새롭게 제안하는 공진점 추종 제어 기법을 사용한 유도가열 시스템을 구현 하여, 이에 대한 시뮬레이션과 실험을 통하여 타당성을 증명하였다.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1968-1970
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• 1997

유도전동기의 속도 제어 장치로 인버터의 사용이 두드러지고 있으며, 소용량 가변속 드라이브에 있어서 그 제어성의 양호한 범용 인버터 구동이 현 인버터 시장의 주류를 이루고 있다. 그러나 범용 인버터는 종래의 TR구동 인버터에 비해 스윗칭 횟수가 많고 데드타임의 영향이 크게 나타난다. 본 논문에서는 유도전동기를 운전하는 범용인버터에 대하여 데드타임으로 인한 문제 해결 및 전류 왜곡 개선 방법을 제안하였고, 이를 실험적인 결과로 입증하였다.

• KSBB Journal
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• v.4 no.3
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• pp.197-202
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• 1989

The existing analog controllers for typical fermentation variables such as rpm and temperature were properly modified in order to be interiaced with microcomputers. Other necessary corrections like the impedance matching, the ground isolation, and the signal range adjustment were done for the successful interfacing between fermentor detectors and computers and for the eventual on-line feedback control of temperature and DO and the induction of the fermentation process with recombinant cells.

• Journal of the Korean Magnetics Society
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• v.6 no.6
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• pp.375-381
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• 1996

This study is conducted to develop the high frequency inductor with ferro-yoke for the surface shape control. A 3- Dimensional simulation program based on the finite element method is developed for calculating electromagnetic field of the high frequency inductor. The validity of the program and the capability to control the liquid metal shape are confirmed by comparison between the results from calculation and those from measurement.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.171-173
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• 2016

일반적으로 대형 버스 및 트럭 등 같은 경우, 부하가 아주 크다. 또한 내리막길이나 장거리 운행 시에 잦은 제동으로 인하여 마찰을 이용한 기존 방식의 브레이크들은 브레이크 파열 및 페이드 현상 때문에 제동 안전성에 문제가 있다. 이러한 제동 부담을 분담하기 위해 현재 보조브레이크(리타더)가 필수적이며, 엔진 계통의 보조브레이크가 아닌 비접촉식 브레이크 같은 친환경 보조브레이크가 요구되고 있다. 그리고 차량 제동시 발생하는 기계에너지를 전기에너지로 회생하여 에너지효율을 향상시키려는 연구가 현재 활발히 진행되고 있다. 본 논문에서는 와전류를 이용한 전자기형 리타더에서 발생되는 전기에너지를 회수하기 위한 전압 제어 방법을 다룰 것이다. 리타더의 제동에너지를 전기에너지로 회생하기 위해 L-C 공진회로로 구성하였다. 리타더를 자여자 유도발전기(Self-Excited Induction Generator)로 모델링 하였고 이를 토대로 시뮬레이션 및 실험을 진행하였다. 자여자 유도발전기의 구동 조건에 대해서 언급하고 이를 파라미터에 따라 3-D map으로 만들었다. 또 회로 중의 FET 게이트에 전압을 인가하는 제어장치의 구동펄스에 따라 바뀌는 공진회로의 전압을 분석하였으며, 이 전압을 제어하기 위하여 PI 제어기를 이용한 알고리즘을 제안하였다. 이 전압을 3상 AC/DC컨버터를 통과한 후 DC/DC컨버터를 통하여 차량 내부의 배터리에 충전되는데 제어를 위해 3상 AC/DC에서의 전압 리플을 MA(Moving Average) 방식의 필터를 사용하여 DC/DC컨버터의 입력에 맞도록 제어하였다. 이와 같이 전자기형 리타더에서 유도되는 전압을 제어기의 제어 펄스에 따라 제어할 수 있으며 Matlab Simulink를 이용하여 리타더의 모델과 그 제어기의 타당성을 보였다. 또 실제 M-G Set 실험을 통하여 그 연관성을 확인하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.181-188
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• 2007

This paper presents a torque control method of a hydraulic actuation system for measuring the dynamic stiffness of missile fin actuators. We propose a new control technique called Dual Dynamic Torque Feedback Control(DDTFC), which improves the stability of the torque control system and enables fast tracking of torque command. The developed control scheme is derived from the physical understanding based on mathematical modelling and analysis. The dynamics of hydraulic torque control servo-system is unravelled via physics-based modelling and nonparametric system identification. In order to verify the effectiveness of the method, the experiment is carried out with a test equipment for measuring the dynamic stiffness. The experiment and simulation results show that DDTFC gives stability improvement.