• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.43-43
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• 2000

당사는 (주)포스콘 진공 사업 부분이 분사하여 1999년 1월 진공 장비 및 제어계측 분야 독립 법인체를 설립하였으며 당사의 주력 제품은 초고진공용 Ion pump 및 controller로서 국산화 개발하여 생산 판매하고 있다. Ion pump 와 controller는 10-4 ~ 10-10 Torr 범위의 초고진공으로 진공 시스템을 배기할 수 있는 장비로서 무소음, 무진동, 저전력의 특성을 가진 초정밀, 초청정 진공 실험에 없어서는 안 될 펌프이다. 현재 당사는 과학기술부의 특정연구개발 과제를 극고진공(XHV)용 Ion Pump를 개발하고 있는 중이다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2399-2411
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• 1995

Crane operation for transporting heavy loads inherently causes swinging motion at the loads due to crane's acceleration or deceleration. This motion not only lowers the handling safety but also slows down the handling process. To complement such a problem, Korea Atomic Energy Research Institute(KAERI) has designed several anti-swing controllers using open loop and closed loop approaches. They are namely a pre-programmed feedback controller and a fuzzy controller. These controllers are implemented on a 1-ton crane system at KAERI and their control performances are compared. Test operations show that the new controllers are superior to that of conventional cranes in terms of robustness to the disturbances and adaptation capability to the change of rope length.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1428-1431
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• 1996

This paper proposes an anti-swing control law for a 2 degrees of freedom overhead crane. The dynamic model of a 2 degrees of freedom crane is highly nonlinear and coupled. The model is linearized and decoupled for each degree of freedom of the crane for small motions of the load about the vertical. Then a decoupled anti-swing control law is designed for each degree of freedom of the crane based on the linearized model. The control law consists of a position control loop and an swing angle control loop. The position loop,. is designed based on the loop shaping method and the swing angle loop is designed via the root locus method. Finally, the proposed anti-swing control law is implemented and evaluated on a 2 degrees of freedom prototype crane.

• Explosives and Blasting
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• v.19 no.4
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• pp.11-22
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• 2001

토목공사장에서 암파쇄 작업은 경제성과 안정성에 지대한 영향을 미치는 작업이다. 본 논문은 대전지역에서 수행된 암파쇄 공법 설계 및 시공사례로서, 현장암반의 특성을 고려한 적정발파공법을 선정하기 위하여 대상 지역의 지질현황을 조사·분석하고, 또한 민원이 첨예한 도로개설 공사장에서 시험발파를 실시하여 이를 토대로 암절취 공법을 선정하여 시공한 사례보고이다. 대전지역의 지질은 선캠브리아기의 변성암류와 변성퇴적암류 및 이를 관입한 심성암류와 중생대 화강암으로 이루어져 있는 복잡한 분포를 이루고 있다. 사례연구 대상 현장은 편상구조가 현저한 관입 편상화강암 및 화강암질 편마암으로 구성되어 있었으며, 시험발파 및 분석결과를 기초로하여 25.5m이내 지역은 HRS 등 무진동 파쇄공법의 적용을 제안하였고, 25.5∼36m 범위의 대부분 지역은 진동제어를 할 수 있는 제어발파공법을 권장하였고, 기타 진동 영향권에서 비교적 안전한 것으로 나타난 지역은 소발파공법을 적용하도록 제안하였다. 제안된 안에 따라 설계를 보완하고 시공한 결과 문제의 발생없이 성공적으로 시공이 완료되었다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.297-304
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• 1997

This paper presents a systematic design method of an anti-swing control law for overhead cranes. A velocity servo system for the trolley of a crane is designed based on the dynamics of the trolley and its load. The velocity servo system compensates for the effects of load swing on the trolley dynamics so that the velocity servo is independent of load swing. The velocity servo system is used for the design of a position servo system for the trolley via the loop shaping method. The position servo system and the swing dynamics of the load are then used to design an angle control system for load swing based on the root locus method. The combined position servo and the angle control systems constitute the overall control system. In the presence of low frequency disturbances, the proposed control law guarantees accurate position control for the trolley and fast damping for load swing. Furthermore, the performance of the proposed control law is independent of the mass of the load. Experimental results on a prototype crane show the effectiveness of the proposed anti-swing control law.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.176-184
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• 2000

TDC(Time Delay Control) deals with the time-varying system parameters, unknown dynamics and unexpected disturbances using time delay. TDC can be divided into two separate parts: an auxiliary controller and a servo controller. The two controllers can be designed independently. The auxiliary controller is used to reduce sensitivity to parameter variations, nonlinear effects, and other disturbances. The servo controller is to reduce the error between the desired command and output. We propose the model-following time delay controller with modified error feedback controller. This was applied to follow the desired reference model for the uncertain time-varying overhead crane. The model generates the damped-out swinging motion trajectory to suppress the swinging motion caused by the acceleration and the deceleration of crane transportation. The control performance was evaluated through simulations. The theoretical results indicate that this control method shows excellent performance to an overhead crane with the uncertain time-varying parameters.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.145-149
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• 1997

General joystick using spring only has a vibration when operaor drops the joystick. If it is used as input of motorized wheelchair, its system have a serious problem which operator fall into dangerous situation. Therefore, In this paper proposed non-vibration joustick which control a motorized wheelchair. Non-vibration joystick was designed which return to origin point when operator drops joystick by mistake. Reflected force of non- vibration joystick is defined as addition displacement and variation rate. And each parameter has elasticity of spring and viscosity of DC servo motor. Through simulation for virtual environment, we found two coefficient to return origin point smoothly when a disabled person drops the joystick. In case of larger elastic coefficient of spring than viscous coefficient, we confirmed the result has the equal vibration of general joystick (under-damping). In opposite case, joystick returned to origin point with excessive force. As a application of non-vibration joystick, we experimented wall-following controlling. In this trial, we corroborated that joystick follows smoothly around the corridors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.671-679
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• 1999

In this paper, humidity measurement is accomplished using humidity sensor, dehumidify is implemented using general-purpose $\mu$-processorPIC16C54 and thermoelectric module for control measured humidity and input target humidity value proportionally Pottier module product is variety kind of size and characteristic, very important drawing factor is selection necessary heat sink, which is maintain proper thermal resistance from variety kind of module also. From electronic dehumidifier is manufacture by using thermoelectric module, no sound, no vibration, low power consumption of partial space efficient dehumidify proves the validity of this system.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.10
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• pp.1683-1693
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• 1997

In this paper, a new nonlinear dynamic model is derived for a 2-dimensional overhead crane based on a new definition of 2-degree-of-freedom swing angle, and a new anti-swing control law is proposed for the crane. The dynamic model and control law take simultaneous travel and traverse motions of the crane into consideration. The model is first linearized for small motions of the crane load about the vertical stable equilibrium. Then the model becomes decoupled and symmetric with respect to the travel and traverse axes of the crane. From this result, a decoupled anti-swing control law is proposed based on the linearized model via the loop shaping and root locus methods. This decoupled method guarantees not only fast damping of load-swing but also zero steady state position error with optimal transient response for the 2-dimensional motion of the crane. Finally, the proposed control method is evaluated by controlling the simultaneous travel and traverse motions of a 2-dimensional prototype overhead crane. The effectiveness of the proposed control method is then proven by the experimental results.

• Journal of Energy Engineering
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• v.15 no.3 s.47
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• pp.202-208
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• 2006

Although the importance of good conservation of historic sites including ancient royal tombs is well aware, still not much attention has been paid for the facilities and systems to preserve those historic sites, which includes precious artifacts as wall paints and carved works, etc. Even the general understanding about the environment of the underground space or tombs is not satisfactory. In the present study, vibration levels due to the operation of an HVAC system to maintain the desired indoor temperature and humidity are investigated experimentally. According to the measured data, the level of vibration inside the present model tomb with the indoor unit inside, showed order of magnitude less values than the Swiss Standards, but still higher than the value suggested by German standards, which is, zero. Further study will be pursued for cases including different ways of installation, because the vibration level depends not only on the system design, but also on the installation methods.