• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.288-290
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• 2006

This paper presents the real-time water tank wireless control in a ship using duplex RF modules and PLC(Programmable logic Controller). The purpose of this paper is developing HMI(Human Machine Interface) for automation equipments. The system can low a cost because long wires are no more used. Analog signals of the water gauge and flow meter are changed to discrete signals by the micro-processor. The PLC checks the volume of water and runs On or Off of the valve and pump. Duplex RF modules send and receive data between the water tank and control room. Everywhere the Internet is used, operators are able to check the status of the system by the web-server.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.741-749
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• 2014

This paper proposes a machine vision module for PLCs (Programmable Logic Controllers). PLC is the industrial controller most widely used in factory automation system. However most of the machine vision systems are based on PC (Personal Computer). The machine vision system embedded in PLC is required to reduce the cost and improve the convenience of implementation. In this paper, we newly propose a machine vision module based on PLC. The image processing libraries are implemented and integrated with the PLC programming tool. In order to interface the libraries with ladder programming, the ladder instruction set was also designed for each vision library. By use of the developed system, PLC users can implement vision systems easily by ladder programming. The developed system was applied to sample inspection system to verify the performance. The experimental results show that the proposed system can reduce the cost of installing as well as increase the ease-of-implementation.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.61-69
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• 2002

This paper describes a converting algorithm between programmable languages of a software PLU. It is based on IEC 61131-3 standard and PC. The proposed control logic is designed by the software model and common element with data type, variables, POUs(program organization unit) and execution control unit commonly used within programmable languages of IEC 61131-3 Standard. The generation method of object file is proposed on five programmable language based on IEC 61131-3. It is represented as fo11ows; 1) the generation method using conversion algorithm from LD to IL with FBD(function block diagram), 2) the generation method using f code generation algorithm from SFC using the SFC execution sequence with FBD and ST(structured text). The proposed control logic generator was implemented by Visual C++ 6.0 and MFC on MS-windows NT 4.0.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1221-1224
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• 2004

This paper presents the programmable logic controller (PLC) networking development for communication with the mobile phone. The proposed technique is suitable for remote sensing control systems, which can display the operation status and monitoring fault diagnosis of a system. The system operation is based on the use of personal computer (PC) to logically analyze data from PLC, and existing internet protocol for sending information messages to mobile phones.

• Journal of KIISE
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• v.43 no.5
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• pp.569-578
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• 2016

The PLC (Programmable Logic Controller) has been widely used for the development of digital control system of nuclear power plant. The PLC has high maintenance costs and increasing complexity, hence, FPGA (Field Programmable Gate Array) based digital control system has been considered as an alternative. However, the development of FPGA based digital control system is a challenge for PLC engineers because they are required to learn about new language to develop FPGA and knowledge and know-how acquired in the development of PLC is not transferable. In this study, we proposed and implemented an automatic translation tool for translation of FBD (Function Block Diagram), a programming language of PLC software, into VHDL (VHSIC Hardware Description Language). Automatically translating the FBD to VHDL using this tool allows PLC engineers to develop FPGA without any knowledge of the hardware description language.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.10
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• pp.1117-1123
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• 2014

Nuclear industries have faced unfavorable circumstances such as an obsolescence of the instrumentation and control system, and therefore nuclear society is striving to resolve this trouble fundamentally. FPGAs are currently highlighted as an alternative means for obsolete control systems. Because of the obsolescence-unaffected characteristics, FPGA should be highly reliable in order to be a replacement for PLC (Programmable Logic Controller). Therefore, it is necessary to establish a software development aspect strategy that enhances the reliability of an FPGA-based controller. The reliability analysis including the MTBF (Mean Time Between Failures) is carried out based on the MIL-HDBK-217F. MTBFs are compared with the FPGA-based controller COMMON-Q PLC. As an analysis result, it shows that the reliability of the FPGA-based controller is better than or equal to that of PLC.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.1
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• pp.33-38
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• 1999

This paper proposes a translation approach for PLCs (Programmable logic controllers) converting ladder diagrams directly to native codes, and describes detailed steps of the method followed by performance evaluation. A general-purpose DSP (Digital signal processor) based implementation validates the approach as well. A benchmark test shows that the Proposed translation framework fairly speeds up execution in comparison with the existing interpretation approach.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1012-1017
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• 1993

In this paper, the instruction set and the architecture of a RISC processor for programmable logic controller is suggested. From the measurement of existing programs, the characteristics of ladder instructions are analyzed. The instruction set is defined so that the existing ladder program can be reused with simple translation. Because bit instructions controls the behavior of word instructions, the processor suits for high level language like SFC. Simulations show that the PLC with the suggested processor is twenty times faster than the PLC with the multi-purpose microprocessor.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.452-457
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• 1999

The recent control system has been changed into the type of PLC(Programmable Logic Controller) control. Up to now, systematic approach of PLC programming or control logic design is not suggested. In this study, the design process of the control logic is systematized and concrete process in each step is suggested. This systematized approach lead developer to be convenient to implement control system. When some error is occurred in the system, this approach enable the developer to analyze the reason of error rapidly and the system is amended according to systematic information of the analysis. The example of control system implementation following this approach is introduced.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.3
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• pp.118-124
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• 2019

Recently, the industrial field has been changed to the smart factory system based on information and communication technology (ICT) in order to improve productivity, quality and customer satisfaction. The most important machine to realize the smart factory is the AGV(automatic guided vehicle) and the adoption of AGV is increasing. Generally, AGV is developed using general purpose PLC(Programmable Logic controller), but the price of AGV is expensive and its volume is large. On the other hand, the industrial field due to space constraints in the workplace is required the low cost AGV which can be minimization, expansion of function, and easily reconfiguration. Therefore, in order to solve these problems, this study is proposed a design method of AGV controller with built-in PLC, and evaluated its performance. In the results of the experimentation, it showed good performance (speed control error = 0.021[m/s], posture control error=2.1[mm]) for the speed and posture control. In this way, when applying the proposed AGV controller in this study to the industrial filed, it is possible to reduce the size and reconfigure at low cost.