Rapid design and reconfiguration of Petri net models for reconfigurable manufacturing cells with improved net rewriting systems and activity diagrams
Rapid design and reconfiguration of Petri net models for reconfigurable manufacturing cells with improved net rewriting systems and activity diagrams
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DOI：
10.1016/j.cie.2009.07.013
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发表时间：
2009-11
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影响因子：
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通讯作者：
Jun Li;X. Dai;Zhengda Meng;Jianping Dou;Xianping Guan
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文献类型：
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作者：
Jun Li;X. Dai;Zhengda Meng;Jianping Dou;Xianping Guan
为了快速响应市场变化，新兴的可重构制造系统（RMS）提出了两个具有挑战性的问题，即如何快速建立初始制造配置的形式化模型以及如何沿着制造配置的变化（重构）从现有模型生成目标模型。针对这些问题，本文提出了一种快速设计RMS的Petri网（PN）形式化模型的方法，用于RMS的监督控制和逻辑控制，以及模型的自动重构方法。首先，我们提出了一个改进的网络重写系统（INRS）的动态操作的网络转换，不像它的宿主网络重写系统，其中的底层PN重写的初始行为特性可以在转换过程中保持。在此基础上，提出了可重构制造单元初始全PN模型快速设计的三阶段方法。该方法首先采用统一建模语言2（UML 2）的活动图描述制造配置，然后将子活动图转换为PN子模型，最后采用INRS方法将PN子模型自动综合为完整的制造配置模型。此外，我们提出了一种模型重构方法，这类PN模型。该方法比较现有和目标制造配置活动图的变化，并将其转换为INRS的网络重写规则。通过应用所得到的规则，现有的PN模型可以重新配置成一个新的目标制造配置。无论是设计方法还是重构方法，所获得的PN模型的行为特性，例如，可以保证活性、有界性或可逆性，从而可以避免验证的努力。最后，通过实例说明了可重构制造单元PN模型的快速设计及其自动重构。结果表明了方法的有效性。
To respond rapidly to the highly volatile market, the emerging reconfigurable manufacturing systems (RMS) have brought forward two challenging issues, namely, how to build rapid a formal model of an initial manufacturing configuration and how to yield the goal model from the existing one along with manufacturing configuration changes (reconfiguration). As for the issues, we present in this paper a method for rapid design of Petri net (PN) formalized models of RMS, intended for supervisory control and logic control of RMS, as well as a method for automated reconfiguration of the models. Firstly, we present an improved net rewriting system (INRS) for dynamically operating net transformation, unlike its predecessor-net rewriting system, where the initial behavioral properties of the underlying PN rewritten can be preserved during the transformation. Subsequently, the paper proposes the three-phase method for rapid design of initial full PN models of reconfigurable manufacturing cells (RMCs). In this method, activity diagrams of Unified Modeling Languages version 2 (UML 2) are used to describe manufacturing configurations, firstly; then the sub-activity diagrams are transformed into PN sub-models; finally, the PN sub-models are automated synthesized into a full model by the approach of INRS. Further, we present a model reconfiguration method for this class of PN models. The method compares changes in activity diagrams of the existing and goal manufacturing configurations and converts them into net rewriting rules of INRS. By applying the rules obtained, the existing PN model can reconfigure into a new one for the goal manufacturing configuration. No matter the design method or the reconfiguration method, the behavioral properties of the obtained PN models, e.g., liveness, boundedness, or reversibility, can be guaranteed and thereby the efforts of verification can be avoided. Finally, rapid design of a PN model of a reconfigurable manufacturing cell, as well as its automated reconfiguration, is illustrated with the help of an example. The result indicates the validity of the methods.