• Title/Summary/Keyword: time Petri nets

Search Result 65, Processing Time 0.032 seconds

Performance evaluations of discrete event system using Petri Nets (페트리 네트를 이용한 이산 사건 시스템의 성능 분석)

  • 최정환;고인선
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1996.10b
    • /
    • pp.1241-1244
    • /
    • 1996
  • This paper present a performance evaluation method for Timed Place Petri Nets modeled by Live-and-Bounded Circuits (LB-circuits) through a bottom-up approach. The method can handle the case for the nets having common resources(CR). The target system is divided into the sub-systems by disconnecting the common Transition-Transition-Path(TTP) or Place-Place-Path (PPP) between sub-systems. The common PPP pattern is classified into Parallel Common Resource (PCR) and Sequential Common Resource (SCR) in detail for handling common resources. We evaluate the performance of each divided sub-system, and calculate the sub-systems affect on the performance of the whole system. The facts are generalized as a theorem. The developed theorem are applied into the performance evaluation of an automated assembly system shown in an example. All the results are verified by simulation.

  • PDF

Hierarchical Colored Petri Nets Based Components for Workflow Systems

  • Zhou Feng;Bo Rui-Feng;Huang Hong-Zhong;Ling Dan;Miao Qiang
    • Journal of Mechanical Science and Technology
    • /
    • v.20 no.10
    • /
    • pp.1527-1533
    • /
    • 2006
  • Workflow systems have benefited the enterprise and customer in many aspects. But with the increasing complexity of the system, workflow design becomes a complicated and time-consuming process. In this paper, we model the system based on the Hierarchical Colored Petri Nets (HCPN) to avoid the complexity of the system, and the super nets of the model are abstracted as independent components to increase the flexibility, acceptability and maintainability of the system. Another important characteristic of this model is its convenience for reuse and workflow mining. The development process of the overhead traveling crane was given to demonstrate the proposed method.

A SCHEDULING ANALYSIS OF FMS USING TPN UNFOLDING (타임패트리 네트 UNFOLDING을 이용한 FMS의 스케줄링 분석)

  • 이종근
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.205-205
    • /
    • 2000
  • In this paper, we are proposed an analysis method of the operation schedule in FMS using Time Petri Nets(TPN) unfolding. TPN's unfolding is one of the analysis methods after changed non-cyclic net from the concurrent net without to expand the state explosion. We are illustrated this proposed to analyze a schedule problem in Ratio-driven FMS modeling.

  • PDF

Protection Systems Modeling and Fault Diagnosis of Power System Using Petri Nets (페트리네트를 이용한 전력계통의 보호시스템 모델링과 고장진단)

  • Choi, Jin-Mook;Rho, Myong-Gyun;Hong, Sang-Eun;Oh, Yong-Taek
    • Proceedings of the KIEE Conference
    • /
    • 1999.07c
    • /
    • pp.1136-1138
    • /
    • 1999
  • This paper describes a new method of the modeling of protection system and fault diagnosis in power systems using Petri nets. The Petri net models of protection system are compose of the operating process of protective devices and the fault diagnosis process. Fault diagnosis model which makes use of the nature of Petri net is developed to overcome the drawbacks of methods that depend on operator knowledge. The proposed method can reduce processing time and increase accuracy when compared with the traditional methods. And also this method covers online processing of real-time data from SCADA.

  • PDF

Performance Evaluation of FMS Using Generalized Stochastic Petri Nets (Generalized Stochastic 페트리네트를 이용한 유연생산시스템의 성능평가)

  • 서경원;박용수;박홍성;김종원
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1994.10a
    • /
    • pp.653-657
    • /
    • 1994
  • A symbolic performance analysis approach for flexible for manufactring systems (FMS) can be formulated based on the integration of Petri Nets (PN) and moment generating function (MGF) concept. In this method, generalized stochastic Petri Nets are used to define performance models for FMS, then MGF nased approach for evaluating stochastic PN is used to derive performance parameters of PN, and finally system performance is calculated. A GSPN model of machine cell is shown to illustrate the proposed method for evaluating such performance indices as production rate, utilization, work-in-process and lead time. The major advantage of this method over existing performance evaluation of FMS is the ability to compute symbolic solutions for performance. Finally future research toward automating performance measure for GSPN models of FMS is discussed.

  • PDF

A Study on the Performance Analysis of Process Model with Resource Constraints in Concurrent Engineering Environment (동시공학 환경에서 자원제약이 있는 프로세스 모델의 성능분석에 관한 연구)

  • 강동진;이상용;유왕진;정용식
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.22 no.51
    • /
    • pp.231-240
    • /
    • 1999
  • A major concern in Concurrent Engineering is the control and management of workload in a period of process. As a general rule, leveling the peak of workload in certain period is difficult because concurrent processing is comprised of various processes, including overlapping, paralleling looping and so on. Therefore, the workload management with resource constraints is so beneficial that effective methods to analyze design process are momentous. This study presents the Timed Petri Nets approach of precedence logic networks, and provides an alternative for users to analyze constraint processes to resolve conflicts of resources. Another approach to Continuous Time Markov Chain using Stochastic Petri Nets is also proposed. These approaches are expected to facilitate resolving resource constrained scheduling problems more systematically in Concurrent Engineering environment.

  • PDF

Modeling Mobility Agents in Supervisory and Controlling Systems Based on Nets within Nets (ICCAS2005)

  • Xiaohui, Hu;Jianwu, Dang;Xingshe, Zhou
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2005.06a
    • /
    • pp.433-437
    • /
    • 2005
  • The goal of our research is to develop a formal modeling methodology for supervisory and controlling systems that have artificially intelligent features. This approach is agent-based and central to the development of the model of mobility agent considering reactivity for real-time purpose and deliberation for optimal realization and safe-fail problems for critical systems like Intelligent Transportation Systems by high-level Petri net. By using nets within nets we investigate the concurrency of the system and the agent in one model without losing the needed abstraction, and synchronous channels are introduced to denote the coordination and communication. Finally an example is demonstrated.

  • PDF

A study on the real time control of flexible manufacturing system using colored and timed Petri Nets (페트리네트를 이용한 유연생산시스템의 실시간 제어에 관한 연구)

  • 노상도;김기범;김종원;이교일
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1993.10a
    • /
    • pp.1099-1104
    • /
    • 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.

  • PDF

Agent-based Mobile Robotic Cell Using Object Oriented & Queuing Petri Net Methods in Distribution Manufacturing System

  • Yoo, Wang-Jin;Cho, Sung-Bin
    • Journal of Korean Society for Quality Management
    • /
    • v.31 no.3
    • /
    • pp.114-125
    • /
    • 2003
  • In this paper, we deal with the problem of modeling of agent-based robot manufacturing cell. Its role is becoming increasingly important in automated manufacturing systems. For Object Oriented & Queueing Petri Nets (OO&QPNs), an extended formalism for the combined quantitative and qualitative analysis of different systems is used for structure and performance analysis of mobile robotic cell. In the case study, the OO&QPN model of a mobile robotic cell is represented and analyzed, considering multi-class parts, non-preemptive priority and alternative routing. Finally, the comparison of performance values between Shortest Process Time (SPT) rule and First Come First Serve (FCFS) rule is suggested. In general, SPT rule is most suitable for parts that have shorter processing time than others.

Pragmatic Reachability Analysis of Bounded Petri Nets based on Unfoldings (언폴딩에 기반한 유한페트리넷의 실용적 도달가능성 분석)

  • Kim, Eui-Seok;Lee, Jeong-Gun;Lee, Dong-Ik
    • Journal of KIISE:Computer Systems and Theory
    • /
    • v.27 no.6
    • /
    • pp.599-607
    • /
    • 2000
  • This paper suggests an efficient reachability analysis method of bounded petri nets. Reachability analysis is a fundamental basis for studying the dynamic properties of any discrete event systems. However, it takes at least exponential execution time and memory space to verify in general petri nets. That is, state space explosion problem may occur. In this paper, we attack problems of previous approaches - state space explosion and restrictions to applicable petri net classes - by formulating the reachability problem as set operation over structural relations among places on an unfolding.

  • PDF