• 한국자동차공학회논문집
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• 제6권4호
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• pp.198-210
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• 1998

A crank angle-based engine control system has been developed for use as an engine research tool to provide precise control of the fuel injection(timing and duration) and ignition(timing and dwell) in real-time. The engine event information is provided by the engine shaft encoder, and the engine control system uses this information to generate spark and injector control signals for relevant cylinders. Eight different engine types and four different rotary encoder resolutions can be accommodated by this system. Also this system allows a user to individually control the ignition and fuel injection for each cylinder in a simple manner such as through a keyboard or in a real-time operation from a closed-loop control program.

• 대한기계학회논문집A
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• 제30권12호
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• pp.1596-1602
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• 2006

In this paper, a hybrid sensor is proposed that has two capabilities: the first is to sense longitudinal or flexural transient vibration signals selectively which are transmitted along the target shaft, and the second to measure the rotating speed of the shaft. All measurements are made in a non-contact manner since this sensor uses magnetostriction as its measuring principle. The signal selection between two vibration modes requires only electrical switching operations and the switching between these two sensing capabilities-vibrations and rotational speed-are accomplished by a very simple mechanical operation. To verify the capabilities of the proposed sensor, a prototype sensor is fabricated and the experiments are made. The results show this sensor can embody two sensing capabilities in one sensor configuration.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1450-1452
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• 2005

AC Servo system has been implemented to semiconductor equipments system for their requirements of the high resolution control. This paper is based on the newly produced DSP TMS320F2812 which has the performance of fast processing speed, 150 MIPS, and rich peripheral interface. The implemented system has been developed for the position control that also has speed and current control as inner loops. The controller implemented a high precision position control system with SVPWM and digital PI control and using high resolution rotary encoder.

• 대한안전경영과학회지
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• 제17권3호
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• pp.363-370
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• 2015

In this paper, the control technique of the stepping motor using back electromotive force(B-EMF) without encoder is investigated. The stepping motor generally uses the rotary encoder to detect the rotor position. Since this method increases the cost and the motor configuration size, the new closed-loop control method applied for the B-EMF was implemented by using current detect circuit, AD-converter, and micro controller unit(MCU). The control loop of stepping motor became very simplified. The current change of stepping motor measured by the amplifier was measured and analyzed, when the missing step is occurred. Based on the data from current feedback, position errors were compensated and confirmed by using AD-converter.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.143-146
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• 2006

In this paper, a hybrid sensor is proposed that has two capabilities: The first is to sense longitudinal of flexural elastic waves selectively which are transmitted along the targe shaft, the second to measure the rotating speed of the shaft. All measurement are made in a noncontact manner since this sensor uses magnetostriction as its measuring principles. Furthermore, the switching between these two sensing capabilities are accomplished by a very simple mechanical operation. To verify the capabilities of the Proposed sensor, an Prototype sensor are fabricated and the experiments are made. The result shows this sensor can embody two sensing capabilities in one sensor configuration.

• 한국정밀공학회지
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• 제12권2호
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• pp.37-47
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• 1995

In recent years, it has been variously developed for testing the accuracy of circular motion of NC machine tools, for example Telescoping Ball Bar Method by Bryan, Circular test Method by Knapp and $r^{-{\theta} }$ Method by Tsutsumi etc., but these methods are all 2-dimentional measuring methods on plane. These simple methods of circular motion accuracy test of NC machine tools have been studied by many reserchers as above, but it is not yet settled in the code of measuring methods of motion errors of NC machine tools, because of errors of measuring units and sensors, and also especially the difficulties of centering of measuring units and the spindle of machining center. In this paper, in use of 2 rotary encoders and 1 magnetic type linear scale with resolution of 0.5 .mu. m, it has become possible for measuring of 3 dimentional space motion accuracy.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.250-256
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• 2009

This paper presents a robotic tower-crane system using encoder and gyroscope sensors as path tracking devices. Tower crane work is often associated with falling accidents and industrial disasters. Such problems often incur a loss of time and money for the contractor. For this reason, many studies have been done on an automatic tower crane. As a part of 5-year 23-million-dollar research project in Korea, we are developing a robotic tower crane which aims to improve the safety level and productivity. We selected a luffing tower crane, which is commonly used in urban construction projects today, as a platform for the robotic tower crane system. This system comprises two modules: the automated path planning module and the path tracking module. The automated path planning system uses the 3D Cartesian coordinates. When the robotic tower crane lifts construction material, the algorithm creates a line, which represents a lifting path, in virtual space. This algorithm seeks and generates the best route to lift construction material while avoiding known obstacles from real construction site. The path tracking system detects the location of a lifted material in terms of the 3D coordinate values using various types of sensors including adopts encoder and gyroscope sensors. We are testing various sensors as a candidate for the path tracking device. This specific study focuses on how to employ encoder and gyroscope sensors in the robotic crane These sensors measure a movement and rotary motion of the robotic tower crane. Finally, the movement of the robotic tower crane is displayed in a virtual space that synthesizes the data from two modules: the automatically planned path and the tracked paths. We are currently field-testing the feasibility of the proposed system using an actual tower crane. In the next step, the robotic tower crane will be applied to actual construction sites with a following analysis of the crane's productivity in order to ascertain its economic efficiency.

• 한국정밀공학회지
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• 제23권8호
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• pp.64-71
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• 2006

In this paper, a uniform speed controller for an ultrasonic rotary motor is developed using the phase-difference method. The phase difference method uses traveling waves to drive the ultrasonic motor. The traveling waves are obtained by adding two standing waves that have a different phase to each other. A compact phase-difference driver system is designed and integrated by combining VCO(Voltage Controlled Oscillator) and phase shifter. Theoretically the relationship between the phase difference in time and the rotational speed of the ultrasonic motor is sine function, which is verified by experiments. Then a series of experiments under various loading conditions are conducted to characterize the motor's performance that is the relationship between the speed and torque. Proportional-integral control is adopted for the uniform speed control. The proportional control unit calculates the compensating phase-difference using the rotating speed which is measured by an encoder and fed back. Integral control is used to eliminate steady-state errors. Differential control for reducing overshoot is not used since the response of ultrasonic motor is prompt due to its low inertia and friction-driving characteristics. The developed controller demonstrates reasonable performance overcoming disturbing torque and the changes in material properties due to continuous usage.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.641-645
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• 1996

Ball screws are used in the feeding system for transmission of driving force. The friction effect between bed and table, which can affect in accuracyin one dimension feeding and describe the dynamic feeding error, could be simplified as a specific model through experiments. The experiments for dynamic feeding errors were performed om tje NC lathe eith a ball screw. The errors in feeding were measured with respect to the variances of feed, spindle speed and motor current for feeding. A rotary encoder and a current sensor were installed with NC lathe.

• 한국정보통신학회논문지
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• 제5권3호
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• pp.563-572
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• 2001

기중기에 사용되는 모터는 모터의 회전수를 제어하기 위하여 타코제너레이터를 사용한다 타코제너레이터는 커플링을 통하여 모터와 연결되어 있으며, 모터가 회전하는 동안 커플링이 마모되어 기중기에 고장을 일으키는 요인이 되고 있다. 본 논문에서는 기중기의 고장을 감소시키기 위하여 모터 의 회전수를 전압으로 변환하는 변환기를 설계한다. 이 장치는 로타리엔코더, 회전수를 계산하는 속도 측정부, LCD 표시부 및 모터의 방향판별회로로 구성된다. 모터의 회전수-전압 변환장치는 모터의 회전수를 측정하여 RPM으로 표시하고, 모터가 6。 회전 후에 모터의 방향을 판별할 수 있다. 그리고 모터가 제한속도를 벗어나면 위험신호를 발생하는 신호와 회전방향을 전압으로 나타내는 신호를 가지고 있어 모터의 비정상적인 동작을 즉시 감지하여 주제어기에 전달한다. 구현된 변환장치는 모의실험과 실험을 통하여 기중기에서 타코제너레이터의 기능을 잘 수행하고 있음을 확인하였다.