• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2023.11a
• /
• pp.139-140
• /
• 2023

기계·기구, 설비 등(이하 "기계설비")의 주요 위험장소에는 작업자를 통제, 격리하기 위해 방호가드를 고정·설치하는 등 안전사고에 대비하고 있다. 다만 방호가드가 개폐가 용이한 구조일 경우 기계설비 등의 작동 중 작업자 임의 개방에 의한 사고위험에 그대로 노출될 우려가 있어 개폐가 가능한 구조의 방호가드에는 기계설비 가동조건과 연동회로가 구성된 인터록장치를 설치하여 안전사고에 대비하는 것이 일반적이다. 다만 인터록장치는 대부분 기계설비의 가동조건과 하드와이어드(hard-wired)로 결선된 단순 구조가 아닌 PLC(Programmable Logic Controller), 터치판넬, 통신장치 등과 다양하게 다소 복잡한 구조로 설치되어 있고, 인터록장치에 사용되는 센서도 구조, 기능, 사용처 등에 따라 매우 다양화되어 방호도어에 설치되는 안전센서의 사양 선정이 잘 못되거나 설치 후 관리가 미흡할 경우 오작동, 기능해지 등으로 인해 또 다른 사고위험에 그대로 노출될 우려가 있다. 따라서 방호가드에 설치된 인터록장치의 기능해지, 관리소홀 등으로 인해 발생한 사고사례, 아차사고 등을 통해 인터록장치 성능 유지관리를 위한 기술적 사항에 대한 기준을 마련할 필요가 있다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2004.08a
• /
• pp.499-503
• /
• 2004

This application-oriented paper describes an automated welding carriage system to weld a thin corrugated workpiece with welding seam tracking function. Hyundai Heavy Industries Corporation has developed an automatic welding carriage system, which utilizes pulsed plasma arc welding process for corrugated sheets. It can obtain high speed welding more than 2 times faster than traditional TIG based welding system. The aim of this development is to increase the productivity by using automatic plasma welding carriage systems, to track weld seam line using vision sensor automatically, and finally to provide a convenience to operator in order to carry out welding. In this paper a robust image processing and a distance based tracking algorithms are introduced for corrugated workpiece welding. The automatic welding carriage system is controlled by the programmable logic controller(PLC), and the automatic welding seam tracking system is controlled by the industrial personal computer(IPC) equipped with embedded OS. The system was tested at actual workpiece to show the feasibility and performance of proposed algorithm and to confirm the reliability of developed controller.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.486-490
• /
• 2004

Programmable logic controller (PLC) is widely used in manufacturing system or process control. This paper presents the design of a 32-bit microprocessor for a sequence control using an Application Specification Integrated Circuit (ASIC). The 32-bit microprocessor was designed by a VHDL with top down method; the program memory was separated from the data memory for high speed execution of 274 specified sequence instructions. Therefore it was possible that sequence instructions could be operated at the same time during the instruction fetch cycle. And in order to reduce the instruction decoding time and the interface time of the data memory interface, an instruction code size was implemented by 32-bits. And the real time debugging as single step run, break point run was implemented. Pulse instruction, step controller, master controllers, BIN and BCD type arithmetic instructions, barrel shit instructions were implemented for many used in PLC system. The designed microprocessor was synthesized by the S1L50000 series which contains 70,000 gates with 0.65um technology of SEIKO EPSON. Finally, the benchmark was performed to show that designed 32-bit microprocessor has better performance than Q4A PLC of Mitsubishi Corporation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.3
• /
• pp.105-110
• /
• 2005

Programmable Logic Controller(PLC) is the most widely utilized among many sorts of existing controller for the design of factory automation control system, and study about a PLC language is peformed actively. In this paper, we proposed the encoding module that we increase input points when increased of the input machine which is going to control it in the FA design that used PLC. Input point is going to be extended with 2-3 points in the state that cannot equip input unit in basic base any more. Then an extension base, a power supply, an extension cable and an output nit must be equipped particularly. Then a cost must be added very much. This paper proposed the encoding module which extended an input in a small quantity, and we confirmed a feasibility through a simulation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.1
• /
• pp.107-112
• /
• 2010

When we design the control system used Programmable Logic controller(PLC), if we program a Sequential Function Chart(SFC), It is easy to understand the sequential flow of control, to maintenance the controller and to describe a program. SFC language is programmed by a single sequence, a select sequence and a parallel sequence. In a select sequence, when the select step is error, the whole process is stopped. If the error step has no connection the whole process, the loss is down when we debugging the program without stopping the whole process. Therefore, this thesis shows the efficient method of remote control for select sequence and we confirmed its feasibility through actual example.

• Journal of Mechanical Science and Technology
• /
• v.19 no.8
• /
• pp.1597-1610
• /
• 2005

The conventional computerized numerical controller (CNC) of machine tools has been increasingly replaced by a PC-based open architecture CNC (OAC) that is independent of a CNC vendor. The OAC and machine tools with an OAC have led to a convenient environment in which user-defined applications can be efficiently implemented within a CNC. This paper proposes a method of diagnosing the cause of operational faults. The method is based on the status of a programmable logic controller in machine tools with an OAC. An operational fault is defined as a disability that occurs during the normal operation of machine tools. Operational faults constitute more than 70 percent of all faults and are also unpredictable because most of them occur without any warning. To quickly and correctly diagnose the cause of an operational fault, two diagnostic models are proposed: the switching function and the step switching function. The cause of the fault is logically diagnosed through a fault diagnosis system using diagnostic models. A suitable interface environment between a CNC and developed application modules is constructed to implement the diagnostic functions in the CNC domain. The results of the diagnosis were displayed on a CNC monitor for machine operators and transmitted to a remote site through a Web browser. The proposed diagnostic method and its results were useful to unskilled machine operators and reduced the machine downtime.

• Proceedings of the KIEE Conference
• /
• 2003.07d
• /
• pp.2239-2241
• /
• 2003

A new RF control system of Pohang Accelerator Laboratory (PAL) storage ring is a subsystem upgraded PAL control system, which is based upon Experimental Physics and Industrial Control System (EPICS). There are 5 control components, Low Level RF System (LRS), Klystron System, Circulator System, Cavity System, Local Cooling Water System (LCW) at the storage ring of PAL. The new RF control system for the storage ring has been under development for one years, first versions of individual VME (Versa Module Europa) Input/output modules under construction and system integration begun. In this system, VMEbus-based hardware is widely used for front-end controllers (FDS), Input/output controller (IOC). A number of Programmable Logic Controller (PLC) and SUN workstations are also used for Operator Interfaces (OPI) in the control system. This paper describes the development VME I/O module to the new control system and how the design of this new system.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2011.06a
• /
• pp.127-128
• /
• 2011

본 논문에서는 Flow 모니터링 및 제어, Graph 출력, Test, History 등의 기능을 제공하는 연소기 제어 시스템을 설계하고 구현한다. Flow 모니터링 및 제어 기능은 각 채널의 현재 유량을 표시하고, 제어할 수 있다. Graph 출력 기능은 현재 채널의 상태를 그래프로 나타낸다. Test는 현재 구성된 환경이 정상적으로 동작하는지 시험하는 기능을 제공하며, Setting은 각 채널의 채널명, Point set, Range, 허용오차를 설정한다. 그리고 History는 저장된 데이터를 읽어와 Error기록, 사용자에 의해 저장된 데이터, 24시간마다 자동 저장되는 데이터를 그래프로 표시해 준다. 본 논문에서 제안한 연소기 제어 시스템을 이용해서 실제 유량을 측정한 결과, 정확한 유량의 측정을 할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.87-90
• /
• 2012

원자력발전소에 사용되는 모든 시스템은 IEEE에서 최고 수준의 안전도인 CLASS 1E로 분류된다. 그중에서 안전계통은 원자력발전소 안전에 관련한 모든 분야를 관리하는 계통이다. 산업이 발전함에 따라 안전계통 또한 그 규모와 복잡성이 높아지고 있고, 이에 적용되는 요구사항 또한 엄격해지고 있다. 따라서 발전소에 적용되는 안전 동작에 대한 기준을 결정하기 위해서 철저한 오류 예측분석이 수행 되어야 한다. 그 중에서도 NUREG-0492로 규정되어 있는 결함수목분석(Fault Tree Analysis)은 연역적 오류 예측 분석방법으로 원자력 발전소, 우주 산업 등에 관련된 분야는 본 방법을 통하여 오류 예측 분석이 이루어 져야한다. 본 논문에서 원전안전계통을 관리하는 구현 모델인 원전안전등급제어기기(Safety Programmable Logic Controller)에 대하여 결함수목분석을 통한 오류 예측 분석을 하였다. 또한, 위의 구조에 대하여 MSC(Message Sequence Chart)를 통한 모델링을 수행하여, 결함수목분석을 적용하는 과정에서 신뢰도 향상을 더하였다.

• The Transactions of the Korea Information Processing Society
• /
• v.6 no.7
• /
• pp.1929-1940
• /
• 1999

In this paper a VLSI design for the automatic magnetizing and inspection system has been presented. This is a design of a peripheral controller, which magnetizes CRTs and computer monitors and controls the automatic inspection system. We implemented a programmable peripheral interface(PPI) circuit of the control and protocol module for the magnetizer controller by using a 0.8um CMOS SOG technology of ETRI. Most of the PPI functions have been confirmed. In the conventional method, the propagation/ramp delay model was used to predict the delay of cells, but used to model on only a single cell. Later, a modified "linear delay predict model" was suggested in the LODECAP(LOgic DEsign CAPture) by adding some factors to the prior model. But this has not a full model on the delay chain. In this paper a new " delay predict equation" for the design of the timing control block in PPI system has been suggested. We have described the detail method on a design of delay chain block according to the extracted equation and applied this method to the timing control block design. And we had descriptions on the other blocks of this system.