利用IDEF/CPN/G2設計方式實作即時型現場監控系統

Abstract

自動化工廠中的即時型現場監控系統開發，主要包括四個步驟：分析、設 計、驗證與實作。本研究提出之IDEF/CPN/G2 設計方式為一完整即時型監 控系統開發的軟體工程。在分析階段，以IDEF進行功能的分析，形成階層 式功能模式。在設計階段，以功能模式為藍圖，繼續使用 IDEF進行控制 流程的設計，形成階層式控制流程模式。在驗證階段，將控制流程模式轉 換為裴氏圖模式，形成階層式裴氏圖模式，利用CPN 的動態模擬，觀察其 安全性、活性及激態的激發順序是否符合系統需求。在實作階段，利用即 時型專家系統G2的推理機將正確且有效的動態裴氏圖模式實現。實現前需 由裴氏圖模式中，萃取知識庫事實與法則，而事實將被結構化為物件，法 則將被結構化為階層式法則知識庫。 IDEF/CPN/G2 設計方式不僅是一套 系統化之方法且具有表達一致性的優點。此外亦可縮短即時型監控系統分 析至實作的時間。論文最後並以一彈型模型澆灌系統的開發為例，說明 IDEF/CPN/G2設計方式的應用。 The installation of a Real-Time Shop Floor Control System (RTSFCS) in a given automated factory usually undergoes four phases: analysis, design, verification and implementation. A IDEF/CPN/G2 approach is proposed for RTSFCS installation. At analysis stage, software IDEF is used for analyzing the functional requirements of underlying shop floor control system and results in its hierarchical functional model. At design stage, IDEF is used again to design control flows in order to meet the requirements of functional model. At verification stage, the generated hierarchical control flow model is transformed into a hierarchical Petri Net model. Here software CPN is used to simulate this Petri Net model, and the behaviors and properties of the model like safeness, liveness, conservativeness, and transitions firing sequences are observed. At implementation stage, facts and rules are abstracted from the hierarchical Petri Net model. From the given rules and facts, a real time expert system called G2 is used for implementation purpose. This IDEF/CPN/G2 approach provides not only a systematic methodology but also a uniform representation. Consequently, the time needed from analysis through design and verification to implementation is reduced dramatically. For the demonstration purpose, this approach is applied to the implementation of a mould filling system.