• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.953-955
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• 2004

This paper describes the information transmission method using communication networks between Remote Terminal Unit(RTU) and Protection and Control system(PCU) of the direct current switchgear for Light Railway Vehicle, and also represents the test result, which carried out in the laboratory. In this test, transmission signal waveform, polling time, response time and request/response frame were measured between RTU and PCU. The field test including the measurements of analog signal and status of the digital logic operation of PCU will be conducted in near future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.410-413
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• 1993

Chamferless peg-in-hole process of the cylindrical type parts using force/torque sensor and vision sensor is analyzed and simulated in this paper. Peg-in-hole process is classified to the normal mode (only position error) and tilted mode(position and orientation error). The tilted mode is sub-classified to the small and the big tilted mode according to the relative orientation error. Since the big tilted node happened very rare, most papers dealt with only the normal or the small tilted mode. But the most errors of the peg-in-hole process happened in the big tilted mode. This problem is analyzed and simulated in this paper using the force/torque sensor and vision senor. In the normal mode, fuzzy logic is introduced to combine the data of the force/torque sensor and vision sensor. Also the whole processing algorithms and simulations are presented.

• 전기학회논문지P
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• 제53권2호
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• pp.70-76
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• 2004

The purpose of interlocking system in railway is to prevent the route for a train being set up and its protecting signal cleared if there were already another, conflicting route set up and the protecting signal for that route cleared. Recently, conventional relays circuitry in industrial field is replaced to computer-based control systems according to the advance of computer and communication technology. Therefore, interlocking systems in railway field are rapidly changing from existing relay-based interlocking system to computer-based electronic ones that executes the vital interlocking logic to assure the safety train routes at trackside signaling equipment room using electronic circuits. So it is very important to verify the performance of developed electronic interlocking system by plentiful laboratory testing before actually application in the railway system. However the laboratory testing in the present state of railway signaling is preformed individually by manual, so very much test time and cost are required. To solve these problems, we are developed the simulator for automatic interlocking inspection in this research. This simulator is able to operate on general personal computer and has following beneficial functions : automatic test sheet generation for inspection, automatic inspection execution and et al. The experiments are executed to test the feasibility of the developed simulator the experimental results have good agreements with the anticipated ones.

• 조명전기설비학회논문지
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• 제12권4호
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• pp.14-19
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• 1998

본 연구의 목적은 저가의 시율레이션용 툴을 개별하는데 있다. 따라서 PLC 프로그랩을 편집하고 모니터할 수 있는 PLC 프로그랩 모듈과, 가상 PLC 시스템과 시뮬레이션 장비를 개발하였다. PLC 모듈과 시뮬레이션 장비는 상호간 링크가 되어 있어서 PLC 프로그랩에 의하여 실시간으로 제어가 가능하고, 마치 실제 설비가 동작이 되는 것과 같은 효과를 얻을 수 있다. 제안한 새로운 툴을 이용하면 모니터상에서 PLC 시스템을 구성하고 가상기계의 응답을 볼 수 있기 때문에 PLC와 기계를 준비할 필요가 없다. 개발된 프로그랭의 타당성올 증명하기 위하여 엘리베이터와 자동 원료 계량 시스템의 PLC 프로그램올 대상으로 실험을 행하였다. 실험결과 개발한 PLC 에율레 이터에 의해 PLC 프로그램 작성 및 가상기계 동작을 통한 PLC프로그램 검증과정이 원할이 이루질 수 있음올 확인하였다.

• 조명전기설비학회논문지
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• 제25권5호
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• pp.22-33
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• 2011

An induction motor operated with a conventional direct self controller(DSC) shows a sluggish response during startup and under changes of torque command. Fuzzy logic controller(FLC) is used in conjection with DSC to minimize these problems. A FLC chooses the switching states based on a set of fuzzy variables. Flux position, error in flux magnitude and error in torque are used as fuzzy state variables. Fuzzy rules are determinated by observing the vector diagram of flux and currents. This paper proposes hybrid fuzzy controller for direct torque control(DTC) of induction motor drives. The speed controller is based on adaptive fuzzy learning controller(AFLC), which provide high dynamics performances both in transient and steady state response. Flux position, error in flux magnitude and error in torque are used as FLC state variables. The speed is estimated with model reference adaptive system(MRAS) based on artificial neural network(ANN) trained on-line by a back-propagation algorithm. This paper is controlled speed using hybrid fuzzy controller(HFC) and estimation of speed using ANN. The performance of the proposed induction motor drive with HFC controller and ANN is verified by analysis results at various operation conditions.

• 한국안전학회지
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• 제29권1호
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• pp.86-92
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• 2014

This paper provides an integrated view on human and system interaction in advanced and automated systems, which adopting computerized multi-functional artifacts and complicated organizations, such as nuclear power plants, chemical plants, steel and semi-conduct manufacturing system. As current systems have advanced with various automated equipments but human operators from various organizations are involved in the systems, system safety still remains uncertain. Especially, a human operator plays an important role at the time of critical conditions that can lead to catastrophic accidents. The knowledge on human error helps a risk manager as well as a designer to create and control a more credible system. Several human error theories were reviewed and adopted for forming the integrated perspective: gulf of execution and evaluation; risk homeostasis; the ironies of automation; trust in automation; design affordance; distributed cognition; situation awareness; and plan delegation theory. The integrated perspective embraces human error theories within three levels of human-system interactions such as affordance level, psychological logic level and trust level. This paper argued that risk management process should dealt with human errors by providing (1) reasoning improvement; (2) support to situation awareness of operators; and (3) continuous monitoring on harmonization of human system interaction. This approach may help people to understand risk of human-system interaction failure characteristics and their countermeasures.

• 한국전기전자재료학회논문지
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• 제33권6호
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• pp.510-514
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• 2020

Vocational education needs to be transformed to cultivate talents with diverse fusion competencies, which is in line with the recent changes that have become a part of the complex technological developments in the 4th Industrial Revolution. Therefore, it is very important for college graduates to obtain employment skills as they are required to prepare for careers within the complex environments of future societies. With the transition to the Internet of Things (IoT)-based control in the manufacturing industry, the development of technological education and related training programs is required to cultivate practical talents for students who have acquired not only the information on existing programmable logic controller (PLC)-based technology, but also that on embedded programming technology. Therefore, to develop an NCS-based education program for analog signal processing to ensure that programming can easily be learned for cultivating practical talent, this study summarizes the opinions of field experts, selects the appropriate NCS competency unit, and designs an adequate technology education training program.

• Journal of Electrical Engineering and Technology
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• 제2권2호
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• pp.178-187
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• 2007

One important issue in power systems is dynamic instability due to loosing balance relation between electrical generation and a varying load demand that justifies the necessity of stabilization. Moreover, Power System Stabilizer (PSS) must have capability of producing appropriate stabilizing signals over a wide range of operating conditions and disturbances. To overcome these drawbacks, this paper proposes a new method for robust design of PSS by using an auto-tuning fuzzy control in combination with Real-Coded Genetic Algorithm (RCGA). This method includes two fuzzy controllers; internal fuzzy controller and supervisor fuzzy controller. The supervisor controller tunes the internal one by on-line applying of nonlinear scaling factors to inputs and outputs. The RCGA-based method is used for off-line training of this supervisor controller. The proposed PSS is tested in three operational conditions; nominal load, heavy load, and in the case of fault occurrence in transmission line. The simulation results are provided to compare the proposed PSS with conventional fuzzy PSS and conventional PSS. By evaluating the simulation results, it is shown that the performance and robustness of proposed PSS in different operating conditions is more acceptable

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.713-716
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• 2003

In recent, the contactless IC card is widely used in traffic, access control system and so forth. Contactless smart cards use a technology that enables card readers to provide power for transactions and communications without making physical contact with the cards. Usually electromagnetic signal is used for communication between the card and the reader. Contactless card is highly suitable for large quantity of card access and data transaction. And its use becomes a general tendency more and more because of the development of RF technology and improvement of requirement for user convenience. This paper describes the hardware module to process contactless protocol for implementation contactless IC card. And the hardware module consists of specific digital logic circuits that analyze digital signal from analog circuit and then generate data & status signal for CPU, and that convert the data from CPU into digital signal for analog circuit.

• 한국콘텐츠학회논문지
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• 제9권6호
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• pp.45-52
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• 2009

최근 제조업에서 제품 설계를 지원하는 디지털 전문가 시스템을 개발하는 사례가 일어나고 있다. 이 시스템은 제조업에서 엔지니어가 프로세스를 통제하고, 생산관리와 시스템 관리 등을 위하여 사용되고 있다. 본 논문에서는 전문가 시스템을 구축하기 위한 온톨로지 기반의 추론 엔진 개발에 대하여 논한다. 전문가 시스템은 한국어를 지원하고 다양한 기능을 가지며, 그래픽한 온톨로지 맵 인터페이스와 퍼지 룰 기능 정의 등의 기능을 갖도록 하였다. 또한, 온톨로지 맵 구축과 온톨로지 기반의 퍼지 추론 방법에 대하여 지식을 표현하는 방법에 대하여 설명한다.