• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.229-232
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• 1996

The position control accuracy of the robot arm is decreased significantly when a long arm robot is operated at high speed. In this case, the robot arm must be modeled as a flexible structure, not a rigid one, and its control system will be necessarily designed with its elastic modes taken into account. In this paper, the vibration control of a one-link flexible robot arm is presented. The robot system consists of a flexible arm manufactured with thin aluminium plate, AC servomotor with a harmonic drive for speed reduction, optical encoder and accelerometer. The system is modeled with limited number of elastic modes, and its parameters are determined from the results of the experiments. The implemented control schemes are LQ control and sliding mode control. The experiments and digital simulations are carried out to test the validity of the system modeling, controller design, and active control implementation.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.8
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• pp.786-791
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• 2009

Recently, digital camera module has been extensively utilized in mobile devices. The digital camera module should be smaller and lighter than digital still camera module to be used in mobile device. But, mobile camera can't get high quality image as good as the one of digital still camera due to the optical limitation of minimized module. Especially, AE system of mobile camera occurs excessive hunting and oscillation due to miniaturization of module. In this paper, improved AE algorithm which is applied fuzzy PI control is suggested to compensate this point.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.8
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• pp.859-866
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• 1988

A high speed frame synchronization system has been realized which generates the frame sync clock from 565Mb/s data stream (the DS-5 digital multiplex hierarchy signal). The design of a frame pattern detector using a parallel detection method brings into low speed operation and resolves the problems due to the high speed operation. The frame synchronization algorithm recommended by CCITT is also realized by designing a sync mode controller. Appropriate design procedures are considered for an efficient hardware design and minimized connection lines. The CAD simulation as well as experiment show that the performance of the newly designed frame synchronization system satisfies the relevant requirements.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.2
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• pp.15-22
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• 2005

This paper represents the sensor combination technique of mobile robot to reduce the ambiguity and uncertainty of environment that prevents the mobile robot from recognizing the path planning and navigation. The sensors such as optical encoder, ultra sonar sensor, and infra-red sensor gathered the dynamic information of mobile robot that are used to detect the obstacle. Therefore, the mobile robot controller with sensor combination is stably demonstrated by the experimental results.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.12B no.1
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• pp.31-36
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• 2002

In a switched reluctance motor drive, it is important to synchronize the stator phase excitation with the rotor position; therefore, the position of rotor is an essential information. Although optical encoders or resolvers are used to provide the position information, these sensors are expensive. Moreover, in the high-speed region, switching angles are fluctuated back and forth out of the preset value, which is caused by the sampling period of the microprocessor. In this paper, a low cost analog encoder suitable for practical applications is proposed. And the control algorithm to generate switching signals using a simple digital logic is presented. The validity of the proposed analog encoder with a proper logic controller is verified from the experiments.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.393-396
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• 1986

A Sun-Position Sensor using four phototransistors and shadow band device has been designed, and a Sun-Tracking System which tracks varying positions of the sun in elevation and azimuth axes has been built and its performance has been analyzed on the basis of indoor experiments and computer simulations. Two permanent-magnetic Step Motors (1.8.deg./step) for the main actuators and a CRC-800A kit with the Z-80CPU for the main controller have been selected to construct the Sun-Tracking System. It has been shown that the Sun-Position Sensor has about 0.5.deg. resolution and 25msec is required for the response of a single step input to reach its steady state.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.568-574
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• 2004

On-line phase tracking of an extrinsic Fabry-Perot interferometer (EFPI) and experimental vibration control of a composite beam with a sensing-patch are investigated. We propose a sensing-patch for the compensation of the interferometric non-linearity. In this paper, a sensing-patch that comprises an EFPI and a piezo ceramic(PZT) is fabricated and the characteristics of the sensing-patch are experimentally investigated. A simple and practical logic is applied for the real-time tracking of optical phase of an interferometer. Experimental results show that the proposed sensing-patch does not have the non-linear behavior of conventional EFPI and hysteresis of piezoelectric material. Moreover, it has good strain resolution and wide dynamic sensing range. Finally, the vibration control with the developed sensing-patch has been performed using Fuzzy logic controller, and the possibility of sensing-patch as a sensoriactuator is considered.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.5
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• pp.467-472
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• 2008

In this paper, we design, implement and apply network physical layer to 100 BaseFx optical cable interface module based on industrial ethernet protocol which is physical layer of EtherCAT that has ensure its open standard ethernet compatibility which having been provided with real time of control in network of intelligent service robot, can be process numerous data to sensor and motor control system. Through BLDC motor control performance tests, we try to propose suitability as internal network of intelligent service robot and automation system.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.255.1-255.1
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• 2014

태양전지 도핑공정은 대부분 퍼니스(furnace)도핑으로 제작된다. 퍼니스 도핑 공정은 고가의 장비와 유지 비용이 요구되며 국부적인 부분의 도핑은 제한적이다. 또한 도핑 시 온도와 공정 시간이 태양전지의 전기적 특성을 결정짓는 중요한 변수 이다. 그리하여 최근 많은 연구가 진행되는 대기압 플라즈마를 이용하여 도핑공정에 응용하고자 한다. 본 연구에서 대기압 방전 시 전원은 DC-AC 인버터를 사용하였다. 인버터의 최대 출력 전압은 최대 5kv, 주파수는 수십 KHz 이다. Ar 가스는 MFC(Mass Flow Controller)를 사용하여 조절하였다. 대기압 플라즈마를 이용한 태양전지 도핑 시 소스와 ground 거리에 따른 대기압 플라즈마의 방전을 열화상카메라(thermo-graphic camera, IR)로 온도의 변화 측정 및 광학적 발광분광법(Optical Emission Spectroscopy, OES)을 통해 불순물(질소, 산소)을 측정 하였다. 웨이퍼 도핑 후 생성된 웨이퍼를 측정 및 분석을 하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.153-154
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• 2006

Development of sorting machine for photo diode and its control system is addressed. The sorting machine for optical communication device requires high positional precision because the alignment is one of the most important point in the sorting process. This sorting method describes how to detect the target chip's angle and position from the wafer. The machine vision system is used for the feedback control. This sorting machine is implemented by motion controller, machine vision and various solenoid valve and is interfaced with RS-232c, GPIB and PCI communication. This system gets the position accuracy within $1{\mu}m$ with our experiments.