• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.1-10
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• 1990

FMS is the system which improves the productivity by making production lines flexible. FMS is composed of manufacturing system, material handling system, and software to control them. FMS is a complicate system; therefore, computer is required to control FMS efficiently. In this paper the concepts of FMS are shortly reviewed and the computer software and programming strategy to control FMS are presented.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.1090-1095
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• 1992

This paper describes the systematic control method of process information transfer and machine cell control in FMS implementation. We have constructed an experimental FMS computer network and control system. The system hardware consists of host computer to manage process data and information transfer of machine cells, cell control computers to control machine cells(NC lathe, machining center). On the other hand, software is made up of oredr management module, NC program searching and generation module, NC part program error check module and cell control module. In this study, we could arrive at conclusion as following : The first, each task could be accomplihed by the efficient information transfer in hierachical computer network. The second, data base system of part programs and process control data is needed for the efficint information transfer and production management. Lastly, expansion of FMS control system could be achieved by the hierachical and decentralized computer control system.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.1
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• pp.137-151
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• 1995

A difficult problem in operating Flexible Manufacturing Systems (FMS) is to control the system in real-time by coordinating heterogeneous machines and integrating distributed information. The objective of the paper is to present the models and methodologies useful to resolve the difficult problem. The detailed objectives can be described in three folds. First, a hierarchical Colored and Timed Petri-Net (CTPN) is designed to control an FMS in real-time. The concerned FMS consists of a loading station, several machining cells, a material handling system, and an unloading station. Timed-transitions are used to represent the timed-events such as AGV movements between stations and cells, part machining activities in the cells. Signal places are also used to represent communication status between the host and the cell controllers. To resolve the event conflicts and scheduling problems, dispatching rules are introduced and applied. Second, an implementation methodology used to monitor and diagnose the errors occurring on the machines during system operation is proposed. Third, a Petri-Net simulator is developed to experiment with the designed control logic.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.10
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• pp.911-917
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• 2000

As many sensors and actuators are used in various automated systems, the application of network to real-time distributed control system is gaining acceptance in many industries. In order to take advantages of networking, however, the network should be carefully designed to satisfy real-time distributed control. This paper presents an implementation method of closed-loop control using Profibus-FMS. In order to implement a closed-loop control system, we used industrial computers with Profibus-FMS network cards and a DC servo motor. Through various experiments, the step response of the control system with network was compared with the reference response without network.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1099-1104
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• 1993

The real time control system for FMS(Flexible Manufacturing System) is implemented at this paper. To achieve this goal, the Colored and Timed Petri-Net model is constructed and used to simulate the real time operation of FMS. Using the Colored and Timed Petri-Net model, evaluating any kind of FMS plant is possible. On-line shceduler, intelligent dispatcher, real time monitor and the simulation model of shop floor are contructed using LAN communication, relational database system in this paper. Finally, this real time control system is applied to the FMS/CIM center at Seoul National University.

• Korean Management Science Review
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• v.8 no.1
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• pp.27-39
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• 1991

This paper describes the instructional flexible manufacturing system(FMS) laboratory facility at Virginia Polytechnic Institute(VPI) which is directed at problems and issues in the design, implementation and control of computer integrated manufacturing systems. It begins with a configuration and an operational description of FMS laboratory facilities. Next, relevant curricula in manufacturing systems design and control, which can use the FMS laboratory for instructional purpose, are introduced, A computer simulation can be used as an excellent tool for analysis prior to implementation of FMS as well as an on-going improvement tool. A brief survey of simulation languages is lastly included.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.85-94
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• 1999

Reconfiguration, expansion, or new establishment of FMS requires the availability of a shop floor control (SFC) system relevant to the FMS since it is closely related with the hardware component of FMS. Due to the expensive cost of its development, significant research efforts have been made to develop an SFC system that is reusable. This paper presents Abstract Machine Tool (AMT) approach applied to develop an SFC sytem that is reusable without additional programming. The AMT model enables us to design the SFC system independently of the hardware-dependent attributes of euqipment; an AMT models a workstation by abstraction and presents an equipment-independent interface to machining cell controller. Specifically, we describe how we formalize the interfaces among equipment in order to build an AMT and how we design the machining cell control software based on AMT models. We also present MACHINIST the machining cell control system for IAE-FMS plant as an implementation example.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1935-1944
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• 1994

FMS is a distributed system composed of various programmable manufacturing hardware such as robots and NC machines. For the autonomous operation of such a system, an integrated software layer for the control and monitoring in needed on top of the manufacturing hardware. However, constructing and maintaining such a software layer is difficult due to the complexity of a underlying FMS and its frequently changing nature. To cope with this problem, this paper proposes an object-oriented FMS integration model, in which objects acting as virtual manufacturing cells are instantiated for each physical cell in the underlying object-oriented database. Various other entities involved in manufacturing processes and their relationship to the cell objects are also captured in the database. This paper describes the structure of this object-oriented FMS database on our prototype implementation called FREE.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.1-13
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• 1991

This paper describes two FMS, which were developed by SAEIL Heavy Industries. One is FMS for machining of circular parts, that are automobile's axle shafts. This system consists of 13 units, including 7 CNC machine tools. The other is FMS for machining of non-circular parts namely casted or steel block within size of 1.2 X 1.2 X 1.5m. This FMS consists of 8-machining centers, 1-automated warehouse, 2-unmanned Robo Trailers, and computer control room. All systems are functioning satisfactorily and so help greately towards automation of Korean industries.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.399-402
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• 1997

The fieldbus is one of the communication networks in control and automation systems and allows the exchange of information between sensors/actuators and controlling elements. By means of the fieldbus, the various field devices can exchange their information among the nodes in the system. In this paper, we implemented the protocol of profibus, a kind of fieldbus for communication in FMS plant model. We applied this fieldbus to the FMS plant model which consists of three stations and eight slave stations.