• 한국정밀공학회지
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• 제12권4호
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• pp.88-99
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• 1995

The demand for automatic manufacturing systems is increasing. Flexible Manufacturing System(FMS) is usually considered as a soluting for the shop floor automation. One of the difficulties in FMS is the communications problem. Since various machineries with different communications protocoles are included, applying a unified scheme is almost impossible. Therefore, a systematic approach is a key point to solve the communication problem. A cell is difined as an automation unit where closely related for a job reside together. A cell is a messenger between upper level computers and lower level machine equipment. In this research, the fonctions of the cell are defined to have more capabilities than conventional cells since a cell can be often a total manufacturing system is a small to medium sized factory. The cell conducts communications with different machines through the communications schemes established here. A set of software system has been developed according to the defined communication. The software has been tested for a simulation and real experiments for proof.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1999년도 춘계학술대회 논문집
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• pp.54-59
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• 1999

본 논문에서는 유연생산시스템 (FMS: Flexible Manufacturing System)의 객체지향 시뮬레이션(OOS: Object Oriented Simulation)에 대한 기존의 연구들을 소개한다. 먼저 FMS와 객체지향시뮬레이션의 일반적인 개념에 대해서 이야기하고 기존의 연구들을 대상 시스템의 추상화(abstraction)과정을 중심으로 분류하여 정리하였다. 추상화 방법론과 FMS를 위한 객체지향시뮬레이션의 현황 및 과제에 대해서도 간략하게 살펴보았다.

• 한국시뮬레이션학회논문지
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• 제7권2호
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• pp.45-62
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• 1998

This research is concerned with buffer management in a multi-cell FMS with an AGVS. Buffers in manufacturing systems are required to reduce blocking and starving caused by breakdowns, variability in process times, and diversity of part routing. Due to the high per unit buffer cost, which primarily consists of floor space and equipment costs, the total capacity of buffers in and FMS is very limited. Proper buffer management can provide a high system efficiency. This paper presents a buffer management model for a multi-cell FMS with an AGVS and a simulation study to compare the proposed model to a conventional buffer management model in a job shop FMS.

• 한국경영과학회지
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• 제29권4호
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• pp.175-187
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• 2004

We consider the simultaneous selection of part routes for multiple part types in Flexible Manufacturing Systems (FMSs). Using an optimization framework we investigate two alternative route assignment policies. The one, called routing mix policy in the literature, specifies the optimal proportion of each part type to be produced along its alternative routes, assuming that the proportions can be kept during execution. The other one, which we propose and call pallet allocation policy, partitions the pallets assigned to each part type among the routes. The optimization framework used is a nonlinear programming superimposed on a closed queueing network model of an FMS which produces multiple part types with distinct repeated visits to certain workstations. The objective is to maximize the weighted throughput. Our study shows that the simultaneous use of multiple routes leads to reduced bottleneck utilization, improved workload balance, and a significant increase in the FMS's weighted throughput, without any additional capital investments. Based on numerical work, we also conjecture that pallet allocation policy is more robust than routing mix policy, operationally easier to implement, and may yield higher revenues.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.17-18
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• 2008

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3232-3238
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• 2010

유연생산시스템은 고자동화 생산시스템일 뿐만 아니라, 사용자와 시장의 요구를 만족시키기 위해 유연한 생산시스템이 요구됨에 따라 작업배정규칙 할당에 있어서 시스템과 작업환경에 많은 제약을 받게 된다. 본 논문에서는 온톨로지 지식 기반의 작업환경을 고려한 유연생산시스템의 작업배경규칙 할당방법을 제시한다. 에이전트를 이용하여 작업장 환경과 작업내용을 모니터링하고, 이에 적합한 작업배정규칙을 온톨로지 지식으로부터 추론하여 시스템에 적용한다. 본 시스템 개발을 위해 멀티에이전트를 지원하는 $JADE^{TM}$ 플랫폼을 이용하였으며, 온톨로지는 Protege를 이용하여 개발되었다.

• 한국경영과학회지
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• 제28권1호
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• pp.1-10
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• 2003

A recent trend In flexible manufacturing systems (FMS) Is to utilize the Identical versatile machines with fast tool delivery devices. Unlike a conventional FMS where parts are fed to the machines with the required tools, tools are acquired from other machines using a tool delivery system and parts can be finished on the same machine In these FMS. Therefore it Is more important problem 4o plan tool flow using tool delivery system In these FMS rather than part flow In conventional FMS. According to the existing study, In FMS 20∼30 percent of the total management cost Is the cost related with tools and It Is possible to reduce the tool Inventory by 40 percent using efficient tool allocation. In this study, In FMS under dynamic tool allocation strategy, a new method of part release considering tool flow at the stage of part release Is proposed. In order to prove the efficiency of the proposed part release It is compared with other part release through simulation experiments. Performance measures in these experiments are the throughput and the number of tardy parts.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
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• pp.174-179
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• 2000

Proposed in the paper is a V-FMS (Virtual Flexible Manufacturing System) model to be used as a prototyping tool for FMS design. The proposed V-FMS framework follows an object-oriented modeling (OOM) paradigm and is based on a set of user requirements for FMS prototyping. The V-FMS model consists of four types of object: virtual device, transfer handler, state manager and flow controller. A virtual device model, which corresponds to a static model in OOM, consists of two parts, shell and core, for reusability. A transfer handler corresponds to a functional model of OOM and it stores low level device commands required to perform job flow operations between giving and taking devices. The state manager and the flow controller constitute a dynamic model of OOM. The proposed V-FMS model has been implemented for a couple of linear type FMS-lines

• 한국군사과학기술학회지
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• 제2권2호
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• pp.83-91
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• 1999

Dynamic characteristic of manufacturing stage is understood and the utilization of each machine is maximized by developing on-line dynamic CAPP system to consider the overloads in the aircraft part manufacturing line. In this paper, a scheme of production planning and scheduling system was proposed through inspection about some predeveloped CAPP system. Developed production planning and scheduling system included process planning module. After precise inspection of some FMS line schema at domestic heavy industry, optimized FMS line was applied to aircraft part manufacturing and repairing factory. By virtue of considering overloads of factory and machine through on-line dynamic CAPP system, the utilization of resources is maximized and manufacturing lead time is minimized.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.512-515
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• 1996

A mass production system was implemented to reduce a manufacturing cost in a way of copying with a strong world market competition. However customer's demands are changing so rapidly and the mass production system is nolonger competitive to meet the demands. FMS (Flexible Manufacturing System) has been introduced as a replacement for the mass production system, but it still does not meet system's requirements. A new manufacturing system, called a holonic manufacturing system(HMS), is emerging. In this paper it is introduced an autonomous cooperative system under the concept of HMS.