• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.213-220
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• 2016

This research aims to develop core technologies for passive carrier (no power in carrier itself) transfer system. The technologies are passive levitation, propulsion, and guidance, which can be great benefits for semiconductor and display manufacturing industries. Passive maglev carrier is necessary to precise position control for quiet and stable transfer operation. However, the structural characteristics of carrier and the installation errors of gap sensors cause the pitch motion. Hence, the controller design in consideration of pitch motion is required. This study deals with the reduction control of carrier pitch motion. PDA controller and PDA controller with pitch control are proposed to compare the pitch angle analysis. The pitch angle and the levitation precision are measured by experiment. Finally, the optimized design of pitch controller is presented and the effects are discussed.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.208-217
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• 1998

본 연구에서는 ER 브레이크와 ER클러치를 피드백작동기로 사용하여 이송테이블의 위치 추적제어를 수행하였다. 이를 위해 먼저 아라빅 검(arabic gum)계통의 ER유체를 자체조성한 후 전기장에 대한 빙햄(Bingham)모델을 실험적으로 도출하였다. 빙햄모델에 근거하여 평판형의 ER브레이크와 실린더형의 ER클러치를 설계 제작하였으며, 계단입력(step input)전기장에 따른 출력토오크특성을 통하여 이들 작동기의 동적모델을 얻었다. 이들 작동기와 연계된 이송테이블시스템의 운동지배방정식을 유도한 후 위치추적제어를 위한 슬라이딩모드제어기를 설계하였다. 제어기 설계시 이송해이블의 부하질량 변화에 대한 시스템 불확실성과 마찰력을 고려하여 제어성능의 강건성을 보장하도록 하였다. 제안된 제어시스템의 제어영역(control bandwidth)을 주파수 영역에서 고찰한 후 여러 레적에 대한 위치추적제어 실험을 수행하였다.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.7 s.196
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• pp.26-32
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• 2007

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.960-961
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• 2008

본 논문에서는 직선 및 곡선구간에서 구동력을 필요로 하는 LCD 패널 생산라인의 이송장비인 OHS 시스템에 적용이 가능한 횡자속 선형전동기의 제어에 관하여 기술한다. OHS 시스템은 클린룸 내에서 이송대차가 천장에 레일과 함께 설치되어 장거리의 직선 및 곡선 이송경로를 가지는 LCD 패널 물류 이송장치이다. 기존 선형전동기들은 그 구조상 곡선구간 구동원으로 적용하기 어렵고, 장거리 이송용으로 사용하기에 상당한 가격적인 부담이 발생된다. 따라서 본 논문에서는 상대적으로 다른 선형전동기와 비교하여 가격적인 부담이 적고, 곡선구간에서 구동력을 발휘할 수 있는 횡자속 선형전동기를 OHS 시스템에 적용하고, 선형전동기의 곡선구간에서의 출력특성을 분석하며, 이동자의 위치검출 방법 및 제어 알고리즘을 제안한다. 제안한 방법은 실제 제작된 OHS 실험장치를 통하여 제어특성을 검증한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.5
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• pp.31-40
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• 2008

Recently, Contactless Power Supply(CPS) system has been broadly studied as a power supply system for Flat Panel Display(FPD) material transfer equipments. In mass production line, CPS systems on material transfer equipment are applied only in the straight sections with single operating vehicle. The formal CPS system was not adequate for curved section nor multiple operating vehicles. Therefore, this paper presents CPS system that consists of straight and curved section with multiple operation vehicles. The circuit topology of CPS system consists of full bridge configured serial-parallel resonant DC/DC converter. The control method for CPS system consists of duty control method on the primary power supply system to maintain constant resonant current. And the secondary power supply systems of multiple vehicles are self controled to maintain constant output voltage. Practically, the test result of dual vehicles on straight and curved section of material transfer equipments were satisfactory, and proved it's applicability on commercial use.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.41.2-41
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• 2004

본 발표에서는, 3차원 형상의 피스톤을 모방절삭이 아닌 CNC절삭을 행하기 위해 고속 이송계의 개발 사례를 다루었다. 여기서 다양한 고속 이송계의 구축형태와 적용 가능한 핵심요소 부품들을 비교하여 고속 이송 시스템으로서의 장단점을 검토하였다. 또한 타원형상의 가공물을 고속으로 처리하기 위한 소프트웨어와 제어보드에 대해 자세히 설명하였다. 비대칭 원형 절삭가공을 위한 장치개발이 공작기계 설계의 축소판이다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.106-107
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• 2014

본 논문에서는 장거리/정밀 이송장치의 추진시스템 동작을 위한 새로운 구조의 영구자석선형동기전동기 및 제어 알고리즘을 제안한다. 제안하는 선형전동기의 이동자는 영구자석을 사용하였으며, 고정자는 각각 독립된 구조를 갖는 집중권선 방식의 코일로 구성되어 있다. 다수의 독립적인 코일 구동을 위하여 아날로그 전류증폭기를 사용하여 전류제어기를 제작하였다. 또한 성능파악을 위해 영구자석선형동기전동기의 축소형 프로토 타입을 제작하였고 실험결과를 통해 제안된 영구자석선형동기전동기의 장거리/정밀 이송장치로서의 적합성을 증명하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.129-135
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• 2014

In the paper, we propose a design method for the logistics transportation system using magnetic levitation that has a good characteristics without mechanical friction, noise and dust. The proposed transportation system consists of a levitation control system and a propulsion control system. Magnetic levitation system is an electromagnetic suspension system in which electromagnet generates magnetic attractive force and the attractive force pulls the rail. We design a PID controller for the current control of electromagnets. We use linear induction motors for propulsion of the proposed logistics transportation system and adapt the space vector PWM method for the propulsion control system. The proposed transportation system using magnetic levitation is verified performances through levitation and propulsion experiments.

• Journal of the Korean Institute of Intelligent Systems
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• v.27 no.2
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• pp.106-112
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• 2017

In the paper, we propose a levitation and a propulsion controller for the magnetic levitation logistic transportation system. The levitation controller is designed considering the mutual influence of the electromagnets to minimize roll and pitch movements. In order to solve the structural disadvantages of the magnetic levitation transportation system, we improve the problem of the existing controller by applying the exponential filter to the reference input. DSP-based control hardware is developed and the levitation control method is verified by levitation experiments to the air gap goal. The propulsion controller uses the space vector voltage modulation method. The propulsion controller is designed to follow the position and velocity profile by detecting the absolute position from the bar code information attached to the rail. The position control result shows satisfactory performance through the propulsion control reciprocating motion experiment.

• Journal of Navigation and Port Research
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• v.29 no.8 s.104
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• pp.747-753
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• 2005

In this paper, as an anti-sway control strategy of container cranes, we investigate a variable structure control in which the moving load follows a given trajectory, whereas both the trolley and hoist controllers achieve their positioning problems. It is crucial, in an automated container terminal, that collisions should be avoided during the transference of containers from one place to another. It is also necessary, in the case of a quay crane, to select suitable loading and unloading trajectories of containers, so that possible collisions with surrounding obstacles are avoided. After a brief introduction of the mathematical model, a robust control scheme (i.e., a second-order sliding mode control that guarantees a fast and precise transference and a suppression of the resulted swing) is presented. Despite model uncertainties and unmodeled actuators dynamics, the swing suppression from the given trajectory is obtained by constraining the system motion on suitable sliding surfaces, which include both the desired path and the swing angle. The proposed controller has been tested with a laboratory-size pilot crane. Experimental results are provided.