• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.11
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• pp.1006-1015
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• 2016

This paper presents preliminary design and performance analysis of a fast and high precision Tracking Mount for 1m Satellite Laser Ranging(SLR) which is development by Korea Astronomy and Space science Institute(KASI). SLR is considered to be the most accurate technique currently available for the precise orbit determination of Earth satellites. The SLR technique measures the time of flight between pulses emitted from laser transmitter and pulses returned from satellites with laser retro-reflector array. It provides millimeter level precision of range measurements between SLR stations and satellites. A fast and high precision Tracking Mount for SLR which is proposed in this research should be capable of day and nighttime laser tracking about the satellites with laser reflectors from 200 km to 36,000 km altitude(geosynchronous orbit). In order to meet this requirement, we performed mechanical design and structural analysis for Tracking Mount. Also we designed the motion control system and conducted pre-performance analysis to obtain good performance results for a fast and high precision Tracking Mount.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.378-385
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• 2000

In this paper, we consider to apply of 2-DOF (Degree of Freedom) PID controller at D.C servo motor system. Many control system use I-PD , PID control system. but the position control system have difficulty in controling variable load and changing parameter. We propose neural network 2-DOF PID control system having feature for removal disturbrances and tracking function in the target value point. The back propagation algorithm of neural network used for tuning the 2-DOF parameter(${\alpha}$,${\beta}$,${\gamma}$,η). We investigate the 2-DOF PID control system in the position control system and verify the effectiveness of proposal method through the result of computer simulation.

• Korean Journal of Optics and Photonics
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• v.11 no.2
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• pp.108-113
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• 2000

This paper presents a simple but novel gain deviation detector scheme which can be used for general gain-clamping systems. By using the difference of ASEJprobe powers extracted from the edges of gain-flattened bandwidth, gain deviation of EDFA can be exactly detected regardless of the operating condition of a constructed EDFA. To prove the vahd1ty of the suggested scheme, we Implemented gain clamping systems on a single EDFA and cascaded EDFA's link and achieved sufficient gam-clamping performance without the elaborate measurement for tlIe determination of control parameters. eters.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.355-356
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• 2008

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.34-40
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• 2000

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.12-16
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• 2002

This paper deals with the measurement of machine parameters of inverter-fed induction motors for an accurate torque control applications such as machine tools and tension control machines. After discussing nonlinearities of both inverter and motor, this paper suggests appropriate compensation and measurement methods. The experimental results show the validity of the proposed method in the operating conditions.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.129-138
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• 2021

Due to the active progress in space programs for various types of ground and space missions, the high agile spacecraft maneuverability is also required. To meet the requirement of the given space missions, the Control Moment Gyros (CMG) for the alternatives of the classical reaction wheels can release the attitude maneuverability restrictions. In addition, the angular rates of the spacecraft is constrained due to the limited actuator characteristics. In this paper, a sliding mode control technique for the attitude control of the spacecraft equipped with the pyramid type of CSCMG(Constant Speed CMG) is designed, and the stability of the control system is guaranteed by using the Lyapunov stability theory. Finally, the control law proposed is analyized by numertical simulations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.280-281
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• 2010

컨테이너의 효율적인 이송은 작업 시간이 곧 비용으로 연결되는 항만에서 가장 중요한 요소이다. 따라서 1990년대 중반부터 세계항만은 RMGC(Rail-Mounted Gantry Crane), RTGC(Rubber-Tired Gantry Crane)등의 크레인이 개발되어 야드에서 컨테이너를 적재하는데 널리 이용되어 오고 있으며, 특히 최근에는 CCD카메라, 각종 센서 둥을 이용하여 트랜스퍼 크레인의 무인화를 위해 수많은 연구가 진행되었고 실용화 된 많은 기술들이 현장에서 사용되고 있으나, 여전히 많은 부분이 연구를 필요로 한다. 특히 RTGC의 경우 RMGC에 비해 무인 자동화 연구개발은 미비한 수준이다. 따라서 본 논문에서 RTGC의 무인자동화 작업을 위한 가장 기초라고 볼 수 있는 수학적 모델링을 기반으로한 고정밀도 주행제어기를 설계하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.1
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• pp.40-47
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• 2004

This paper proposes a three-axis coupling controller designed to improve the contouring accuracy in machining of 3D nonlinear contours. The proposed coupling controller is based on an innovative 3D contour error model and a PID control law. The novel contour error model provides almost exact calculation of contour errors in real-time for arbitrary contours and can be integrated with any type of existing interpolator. In the proposed method, three axes of motion are coordinated by the proposed coupling controller along with a proportional controller for each axis. The proposed contour error model and coupling controller are evaluated through computer simulations. The simulation results show that the proposed 3-axis coupling controller with the new contour error model substantially can improve the contouring accuracy by order of magnitude compared with the existing uncoupled controllers in high-speed machining of nonlinear contours.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.4
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• pp.64-71
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• 2004

The growing need for higher precision and productivity in manufacturing industry has lead to an increased interest in computer numerical control (CNC) systems. It is well known fact that the cross-coupling controller (CCC) is an effective method for contouring applications. In this paper, a multi-axis contour error controller (CEC) based on a contour error vector using parametric curve interpolator is introduced. The contour error vector is a vector from the actual tool position to the nearest point on the desired path. The contour error vector is the closest error model to the contour error. The simulation results show that the CEC is more accurate than the conventional CCC for a biaxial motion system. In addition, the experimental results on 3-axis motion system show that the CEC is simply applied to 3-axis motions and contouring accuracy is significantly improved.