• 조명전기설비학회논문지
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• 제18권1호
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• pp.115-121
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• 2004

본 연구에서는 프랜트 및 빌딩자동제어 분야에서 적용이 확대 되고 있는 LonWorks 필드버스를 이용하여 기존의 공기조화시스템를 제어하고 있는 DDC제어기를 대체할 수 있도록 필드버스에서 사용이 가능한 고성능 저가의 지능형 제어모듈을 개발하였다. 이는 필드버스 기반의 AHU 전용 지능형제어기를 새로운 설계기술로 개발하고 상품화를 실현하였다. 특히 S/W부분에서도 8 bit Neuron chip에 매우 콤팩트하게 내재된 고성능 응용프로그램도 개발하였다. 공조기의 실험시스템을 구축하여 개발된 전용 제어기를 실험한 결과 밸브, 댐퍼제어 및 감시기능이 기존 DDC 제어기보다 우수함을 확인하였다.

• Journal of Biosystems Engineering
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• 제15권2호
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• pp.110-122
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• 1990

This study was undertaken to develop the feed rate control system for the head feed thresher by making use of the microprocessor and to evaluate the response of the system to a various threshing conditions. The control unit was composed of one-board microcomputer. The speed of the wet-paddy feeding chain was controlled by dc moter with PI controller. It was used the adaptive control method to maintain the constant feed rate regardless of the fed rice varieties. The sliding type potentiometer was used as the feed rate sensor, which was attached on the sheaf-holding apparatus. The mathematical models of the system components were derived and computer simulation was developed for investigating the parameters affecting on control performance and for estimating the response of the system. A one-board microcomputer-based feed rate control system developed in this study was properly functioned and assessed as adequate for the feed rate control system of the head feed thresher. Based on the simulation for the bundle feed, it was anticipated that the lower setting value of the cylinder speed(RL) is to be set higher than the limiting operational speed. In addition, the higher setting value of the cylinder speed(RH) is to be set lower than the limiting cylinder speed for threshing. The computer simulation for the continuous spread feed showed that the lower the setting value of straw layer thickness(LL) was set, the shorter the correction time. However, if too low LL may be established, the feed rate could not reach to its desired rate.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.764-769
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• 2003

The paper introduces a development result for displacement measurement system of multiple moving objects based on image processing technique. The image processing method adopts inertia moment theory for obtaining the centroid of the targets and basic processing algorithms of gray, binary, closing, labeling and etc. To get precise displacement measurement in spite of multiple moving targets, a CCD camera with zoom is used and the position of camera is changed by a pan/tilt system. The fiducial marks on the fixed positions are used as the sensing points for the image processing to recognize the position errors in directions of X -Y coordinates. The precise alignment device is pan /tilt of X - Y type and the pan/tilt is controlled by DC servomotors which are driven by 80c196kc microprocessor based controller. The centers of the fiducial marks are obtained by a inertia moment method. By applying the developed precise position control system for multiple targets, the displacement of multiple moving targets are detected automatically and are stored in the database system in a real time. By using database system and internet, displacement data can be confirmed at a great distance and analyzed. The developed system shows the effectiveness such that it realizes the precision about 0.12mm in the position control of X -Y coordinates.

• 한국정밀공학회지
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• 제21권10호
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• pp.86-93
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• 2004

This paper presents the remote measurement of the ECU signals adopted with KWP 2000 protocol using the wireless communication technique of bluetooth. The bluetooth technology will be the most promising network paradigm which can open the new area in the information technology. Especially, bluetooth module is able to link all the electrical products and personal computers to cellular phone or PDA. This research has a try to design a wireless measurement model of ECU signal based on the car telemery system using bluetooth device. In order to measure the ECU signals, we designed the interface circuits which is able to communicate between the ECU system and the terminal circuits according to the ISO, SAE regulation of communication protocol standard. A microprocessor S3c341 OX is used for the system control and communication of ECU signals. The embedded system software is programmed to measure the ECU signals using the ARM compiler and ANCI C based on Micro/OS-II kernel to communicate between two bluetooth modules using bluetooth stack. The remote measurement of ECU signals using the bluetooth was designed and implemented to evaluate the performance of wireless network to the transmit measurement data. The possibility for the remote measurement of the self diagnosis signals of ECU adopted with KWP2000 protocol verified through the developed systems and algorithms in embedded system.

• 대한임베디드공학회논문지
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• 제4권2호
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• pp.55-62
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• 2009

The power consumption of a high-end microprocessor increases very rapidly. High power consumption will lead to a rapid increase in the chip temperature as well. If the temperature reaches beyond a certain level, chip operation becomes either slow or unreliable. Therefore various approaches for Dynamic Thermal Management (DTM) have been proposed. In this paper, we propose a learning based temperature prediction scheme for a multi-core system. In this approach, from repeatedly executing an application, we learn the thermal patterns of the chip, and we control the temperature in advance through DTM. When the predicted temperature may go beyond a threshold value, we reduce the temperature by decreasing the operation frequencies of the corresponding core. We implement our temperature prediction on an Intel's Quad-Core system which has integrated digital thermal sensors. A Dynamic Frequency System (DFS) technique is implemented to have four frequency steps on a Linux kernel. We carried out experiments using Phoronix Test Suite benchmarks for Linux. The peak temperature has been reduced by on average $5^{\circ}C{\sim}7^{\circ}C$. The overall average temperature reduced from $72^{\circ}C$ to $65^{\circ}C$.

• Nuclear Engineering and Technology
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• 제50권4호
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• pp.570-581
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• 2018

Recently, a software program has been used in nuclear power plants (NPPs) to digitalize many instrumentation and control systems. To guarantee NPP safety, the reliability of the software used in safetycritical instrumentation and control systems must be quantified and verified with proper test cases and test environment. In this study, a software testing method using a simulation-based software test bed is proposed. The test bed is developed by emulating the microprocessor architecture of the programmable logic controller used in NPP safety-critical applications and capturing its behavior at each machine instruction. The effectiveness of the proposed method is demonstrated via a case study. To represent the possible states of software input and the internal variables that contribute to generating a dedicated safety signal, the software test cases are developed in consideration of the digital characteristics of the target system and the plant dynamics. The method provides a practical way to conduct exhaustive software testing, which can prove the software to be error free and minimize the uncertainty in software reliability quantification. Compared with existing testing methods, it can effectively reduce the software testing effort by emulating the programmable logic controller behavior at the machine level.

• 한국해양공학회지
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• 제16권1호
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• pp.64-70
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• 2002

This paper shows the results of the development of a small size of digital type continuous and intermittent welding auto-carriage based on microprocessor (Intel 80196KC) for welding process with long welding line. The developed welding auto-carriage loads welding torch and tracks welding line. It is an automaton largely used for welding process with a lot of long welding lines such as shipbuilding and structure. Most traditional auto-carriages have been developed based on analog circuit for open loop control. So this analog circuit welding auto-carriage cannon control welding speed. Specially welding auto-carriage for intermittent welding condition is so complicated and has the low precision of control performance in welding distance and non-welding distance. The auto-carriage developed in this paper has the following characteristics: It has not only functions of traditional carriage but also functions such as pseudo-welding process of big iron structures, intermittent welding in order to limit heat for welding thin plates, crater treatment of the final step of welding, acceleration at the initial step of welding and deceleration in the final step of welding. The main control board of auto-carriage, power supply system and DC motor drive wee developed and manufactured. The welding speed and the welding distance of the developed auto-carriage are controlled accurately by feedback control using photo-sensor. Hardware and software robust against the heat and noise produced on the welding process are developed.

• 조명전기설비학회논문지
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• 제19권3호
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• pp.17-26
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• 2005

본 연구에서는 유도전동기 구동 시스템에서 새로운 RPWM 방식을 제안하였다. 유도전동기 구동 시스템에서 발생하는 소음을 줄이기 위하여 공간벡터 RPWM방식에 기반을 둔 RPWM방식을 제안하였다. 제안된 RPWM방식을 드럼 세탁기에 적용하여 세탁기에서 발생하는 소음과 진동을 측정하였으며 그 결과를 비교하였다. 제안된 방식의 타당성을 입증하기 위하여 시뮬레이션과 실험을 수행하였다.

• 전기학회논문지
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• 제57권9호
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• pp.1485-1490
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• 2008

This paper proposes a new Fourier transform-based phasor estimation method to eliminate the adverse influence of the exponentially decaying dc offsets when Discrete Fourier Transform (DFT) is used to calculate the phasor of the fundamental frequency component in a relaying signal. By subtracting the result of odd-sample-set DFT from the result of even-sample-set DFT, the information of dc offsets can be obtained. Two dc offsets in a relaying signal are treated as one dc offset which is piecewise approximated in one cycle data window. The effect of the dc offsets can be eliminated by the approximated dc offset. The performance of the proposed algorithm is evaluated by using computer-simulated signals and EMTP-generated signals. The algorithm is also tested on a hardware board with TMS320C32 microprocessor. The evaluation results indicate that the proposed algorithm has the stable and accurate eliminating performance even if the input signal contains two decaying dc components having different time constants.

• 태양에너지
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• 제18권3호
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• pp.25-30
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• 1998

PTC용 태양추적장치는 최대 집열을 위하여 PTC를 항상 태양광이 입사되는 방향으로 일치시키기 위한 자동제어시스템이다. 본 연구는 마이크로프로세서를 사용하는 PTC용 1축 태양추적장치의 개발에 관한 것이다. 개발된 태양추적장치는 태양 위치를 판별하는 태양 센서와 DC 모터 위치제어기로 구성되어 있으며, 80c196KC를 사용하는 제어장치는 아날로그 입력 장치, 24V DC 서보모터제어기, 디지털 I/O로 구성되어 있다. 태양센서는 photodiode를 사용하여 제작되었으며, 태양센서의 법선 방향으로부터 ${\pm}50^{\circ}$ 이내에 위치하는 태양을 감지할 수 있도록 설계되었다. 본 연구에서 개발된 태양추적장치는 현재 한국에너지기술연구소에 설치되어 있는 PTC에서 사용되고 있으며, 태양추적 정확도에 관한 연구가 현재 진행되고 있다.