• 제목/요약/키워드: Flexible Manufacturing Systems

검색결과 317건 처리시간 0.029초

운동 중인 유연한 구조물의 동적 해석 (Dynamic Analysis of a Flexible Structure in Motion)

  • Sin Young Lee
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 추계학술대회
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    • pp.390-395
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    • 2003
  • Moving flexible structures such as transfer systems in press machine, crane, working table of machine tools have vibration problems because of starting, feeding and stopping. An analysis method is suggested and experimentally studied in order to solve a vibration problem of a moving flexible structure. In this method, the concepts of substructure synthesis method and semi-static displacement including rigid body mode were used. Total deformation of a structure was assumed to be composed of quasi-static and dynamic components. Experimental results from an elementary model of a transfer feeder showed good agreements with computational results.

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인공 뉴럴 네트워크에 의한 FMS 일정관리 (FMS scheduling through artificial neural network)

  • 양정문;문기주;김정자
    • 산업경영시스템학회지
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    • 제18권34호
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    • pp.99-106
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    • 1995
  • Recently, neural network is recognized as a new approach to solve jobshop scheduling problems in manufacturing system. Scheduling problem is known to be a difficult combinational explosive problem with domain-dependence variations in general. In addition, the needs to achieve a good performance in flexible manufacturing system increase the dimensions of decision complexity. Therefore, mathematical approach to solve realistic problems could be failed to find optimal or optimal-trending. In this paper a technique with neural network for jobs grouping by job-attributes and Gaussian machine network for generating to near-optimal sequence is presented.

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유연제조시스템을 Petri Nets으로 구현하고, 결과를 다른 시뮬레이션과 비교, 검토 (Modeling, Analysis of Flexible Manufacturing System by Petri Nets)

  • 이종환
    • 산업경영시스템학회지
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    • 제28권3호
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    • pp.36-41
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    • 2005
  • 페트리 네트(Petri Nets)는 이산 사건 시스템을 모델링할 수 있는 그래픽하고, 수학적인 도구이다. 본 연구는 유연제조 시스템을 확률적인 페트리 네트(Stochastic Petri Nets)중의 하나인 임베디드 마코프 체인(Embeded Markov Chain)에 도입하고, 임베디드 마코프 체인의 방법 중에 하나인 일반화된 확률적 페트리 네트(Generalized Stochastic Perti Nets)에 적용시켰다. 그리고 결과치의 정확성을 알아내기 위하여, 페트리 네트 시뮬레이션과 아레나를 사용하여 실행하였다.

자동생산체제(自動生産体制)(FMS)에서의 생산일정계획(生産日程計劃) (A Scheduling Heuristic Alogorithm for Flexible Manufacturing Systems)

  • 노인규;최정상
    • 대한산업공학회지
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    • 제14권1호
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    • pp.73-82
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    • 1988
  • This research is concerned with production scheduling for FMS (Flexible Manufacturing System) which consists of machine centers served by cycle conveyor. The objective of the research is to develop and evaluate scheduling procedures to minimize the mean flow time. An optimal algorithm called SCTF (Shortest Circle Time First) is proposed when the conveyor runs at minimum possible speed (CS=1) and a heuristic algorithm called SCTJMF (Shortest Cycle Time and Job Matching Algorithm) is suggested when the conveyor runs at double speed (CS=2). The evaluation of the heuristic algorithm was implemented by comparison with the optimal algorithm for 112 experimentations for CS=1 and random schedule. The results showed that the proposed heuristic algorithm provides better solution that can be regarded noticeable when compared with SCTF algorithm and random scheduling.

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단일 유연 모드를 가지는 시스템의 잔여 진동을 최소화하기 위한 제어 전략 (A Control Strategy for Systems with Single Flexible Mode to Reduce Residual Vibration)

  • 신영주
    • 한국정밀공학회지
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    • 제24권11호
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    • pp.91-100
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    • 2007
  • Many manufacturing devices must execute motions as quickly as possible to achieve profitable high-volume production. Most of them have devices having flexibility and a time delay of one sampling is added to the plants when they are controlled by fast discrete controllers, which brings about non-minimum phase zeros. This paper develops a control strategy that combines feedforward and feedback control with command shaping for such devices. First, the feedback controller is designed to increase damping and eliminate steady-state error. Next, the feedforward controller is designed to speed up the transient response. Finally, an appropriate reference profile is generated using command-shaping techniques to ensure fast point-to-point motions with minimum residual vibration. The particular focus of the paper is to understand the interactions between these individual control components. The resulting control strategy is demonstrated on a model of a high-speed semiconductor manufacturing machine.

유연생산 시스템의 최적 복수 경로 계획 (Optimal Planning of Multiple Routes in Flexible Manufacturing System)

  • 김정섭
    • 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.

유연생산셀의 지능형 스케쥴링을 위한 전문가 시스템 (An expert system for intelligent scheduling in flexible manufacturing cell)

  • 전병선;박승규;이노성;안인석;서기성;이동헌;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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    • pp.1111-1116
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    • 1993
  • In this study, we discuss the design of the expert system for the scheduling of the FMC(Flexible Manufacturing Cell) consisting of the several versatile machines. Due to the NP property, the scheduling problem of several machine FMC is very complex task. Thus we proposed the two heuritstic shceduling algorithms for solving the problem and constituted the algorithm based of solving the problem and constituted the algorithm base of ISS(Intelligent Scheduling System) using them. By the rules in the rule base, the best alternative among various algorithms in algorithm base is selected and applied in controlling the FMC. To show the efficiency of ISS, the scheduling output of ISS and the existent dynamic dispatching rule were tested and compared. The results indicate that the ISS is superior to the existent dynamic dispatching rules in various performance indexes.

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FMS의 생산계획 및 일정계획을 위한 단계적 해법에 관한 연구 (Hierarchical approaches for the FMS production planning and scheduling problems)

  • 장성용;박진우
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
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    • pp.195-208
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    • 1990
  • Flexible Manufacturing System(FMS) is an integrated, computer controlled complex of automated material handling devices and numerically controlled machine tools that can simultaneously process medium-sized volumes of a variety of part types. This paper discusses planning problems that can be solved for efficient use of an FMS and present an integrated decision support system for FMS production planning and scheduling problems. FMSDS(Flexible Manufacturing Systems Decision Support System) consists of data handling modules, part selection module, loading module, load adjusting module, scheduling module and simulation module etc. This paper presents the solution methodology of each subproblems and integrated interfaces between subproblems using hierarchical approaches and loop controls considering the relationships between subproblems. A case study by this model is presented.

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유연생산시스템의 기계와 AGV의 동적 작업배정규칙 비교연구 (A Comparative Study of Dynamic Dispatching Rule for Machine and AGV of Flexible Manufacturing System)

  • 이성우
    • 한국산업융합학회 논문집
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    • 제12권1호
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    • pp.19-25
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    • 2009
  • We suggest and evaluate a dynamic scheduling rule of machines and material handling systems for on-line operation in job shop type Flexible Manufacturing System. Alternating status should be able to take operation scheduling procedures and without delay in dynamic industrial environments effectively. The interaction(SPT-NS, SPT-QSNS, SPT-NUJ, EDD-NS, EDD-QSNS, EDD-NUJ, CR-NS, CR-QSNS, CR-NUJ) between machine operation scheduling and AGV dispatching rule were also studied in this research. The performance evaluation which was obtained from DSS compares the performance of Flow time, and Empty to loaded travel ratio. It is Compared with the best rules & two system.

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FMS 환경하의 효율적인 버버관리에 관한 연구 (An Efficient Buffer Management in a Multi-Cell Flexible Manufacturing Systems)

  • 이정표
    • 한국시뮬레이션학회:학술대회논문집
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    • 한국시뮬레이션학회 1998년도 추계학술대회 및 정기총회
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    • pp.128-132
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    • 1998
  • This research is concerned with buffer management in a multi-cell FMS(Flexible Manufacturing System) with an AGVS(Automated Guided Vehicle System). To reduce blocking and starving caused by breakdowns, variablility in process times, and diversity of part routing, buffer is needed. Due to the high per unit buffer cost, which primarily consists of floor space and equipment cost, the total capacity of buffers in an FMS is very limited. Therefore, 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.

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