共查询到18条相似文献,搜索用时 109 毫秒
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可重构制造系统重构算法的实例研究 总被引:19,自引:0,他引:19
可重构制造系统(RcMS)的模型及其重构算法是可重构制造系统的形式化表示,是研究RcMS优化的理论基础,基于赋时可重构Petri网的可重构制造系统模型(TRPN-RcMS)及其重构算法是RcMS的形式化表示方法之一。文中以实例对RcMS重构算法进行说明和论证。首先假设一个RcMS的实例系统;然后,根据RcMS的当前系统组成及其生成计划生成RcMS当前系统的TRPN-RcMS模型;最后,根据RcMS重构后的系统组成及其生产计划的变化情况,利用RcMS的TRPN-RcMS模型的重构算法,生成重构后的系统的TRPN-RcMS模型。 相似文献
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提出了一种基于多Agent的可重构制造系统故障诊断自学习模型,模型为3层结构,从下向上分别为监测Agent层、诊断Agent层和管理Agent层,详细分析了模型的故障诊断自学习机理,自学习性是基于数据挖掘和基于粗糙集的.示例表明可重构制造系统重构前后,均能有效完成故障诊断. 相似文献
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应用控制、管理和维护一体化的自动化技术,建立了基于多Agent的可重构制造系统RMS(Reconfigurable Manufacturing System)集成模型。该模型集成了基于多Agent 的RMS重构模型、控制模型和故障诊断模型,将RMS的控制、管理和维护联系起来,并给出了该模型的UML(Unified Modeling Langurage)活动图,最后举例验证了模型的可行性。 相似文献
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针对目前可重构制造系统评价体系的不足,根据可重构制造系统的特点和要求,以某研究所机械加工车间为研究对象,从工程应用的实际出发,构建了一个较为完备的可重构制造系统的评价体系模型,并通过层次分析法对可重构制造系统的各级指标进行量化,在此基础上,运用模糊综合评价方法对系统进行综合评价打分,从而达到对系统的可重构性进行控制的目的。并借助PowerBuilder软件进行评价界面的设计,解决了复杂的计算问题,提高评价的准确度与时效性。 相似文献
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Automatic Reconfiguration of Petri Net Controllers for Reconfigurable Manufacturing Systems With an Improved Net Rewriting System-Based Approach 总被引:1,自引:0,他引:1
Jun Li Xianzhong Dai Zhengda Meng 《Automation Science and Engineering, IEEE Transactions on》2009,6(1):156-167
The advent of reconfigurable manufacturing systems (RMSs) has given rise to a challenging problem, i.e., how to reconfigure rapidly and validly a RMS supervisory controller in response to frequent changes in the manufacturing system configuration driven by fluctuating market. This paper presents an improved net rewriting system (INRS)-based method for automatic reconfiguration of Petri net (PN) supervisory controllers for RMS. We begin with presenting the INRS which overcomes the limitations of the net rewriting system and can dynamically change the structure of a PN without damaging its important behavioral properties. Based on INRS, a method for design reconfigurable PN controllers of RMS is introduced. Subsequently, we presented an INRS-based method for rapidly automatic reconfiguration of this class of PN controllers. In the reconfiguration method, changes in a RMS configuration can be formalized and act on an existing controller to make it reconfigure rapidly into a new one. Noticeably, no matter the design or reconfiguration, the expected behavioral properties of the resultant PN controllers are guaranteed. Thus, efforts for verification of the results can be avoided naturally. We also illustrate the reconfiguration of a PN controller for a reconfigurable manufacturing cell. 相似文献
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Sihan Huang Guoxin Wang Xiwen Shang Yan Yan 《Journal of Intelligent Manufacturing》2018,29(5):1031-1043
To address the problem of how to identify the best time to implement reconfiguration for the reconfigurable manufacturing system (RMS), a dynamic complexity-based RMS reconfiguration point decision method is proposed. This method first identifies factors that affect RMS dynamic complexity (including both positive and negative complexity) at the machine tool and manufacturing cell levels. Next, based on information entropy theory, a quantitative model for RMS dynamic complexity is created, which is solved via state probability analysis for processing capability and the processing function. This model is combined with cusp catastrophe theory to establish an RMS reconfiguration decision model. Both positive and negative complexity are control variables for cusp catastrophe. Cusp catastrophe’s state condition is used to identify RMS state catastrophe at the final stage of production. This catastrophe point is the RMS reconfiguration point. Finally, the case study result shows that this method can effectively identify the RMS state catastrophe moment so that system reconfiguration is implemented promptly to improve RMS’s responsiveness to the market. 相似文献
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可重构资源管理及硬件任务布局的算法研究 总被引:1,自引:0,他引:1
可重构系统具有微处理器的灵活性和接近于ASIC的计算速度,可重构硬件的动态部分重构能力能够实现计算和重构操作的重叠,使系统能够动态地改变运行任务,可重构资源管理和硬件任务布局方法是提高可重构系统性能的关键.提出了基于任务上边界计算最大空闲矩形的算法(TT-KAMER),能够有效地管理系统的空闲可重构资源;在此基础上使用FF和启发式BF算法进行硬件任务的布局.实验表明,算法能够有效地实现在线资源分配与任务布局,获得较高的资源利用率. 相似文献
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可重构制造系统监督控制器的自动重构 总被引:2,自引:0,他引:2
提出了基于改进的网重写系统(Improved net rewriting system, INRS)的可重构制造系统(Reconfigurable manufacturing systems, RMS) Petri网监督控制器的自动重构方法, 以快速适应由市场需求变化所引起的制造系统构形的频繁变化. INRS解决了网重写系统存在的问题, 可动态调整给定Petri网模型的结构而不改变其行为属性. 以集合和图的组合形式定义了RMS的构形, 并提出了基于INRS的一类模块化、可重构的Petri网控制器的设计方法. 针对这类Petri网控制器, 提出了基于INRS的自动重构方法. 方法可将RMS构形的变化转变为INRS的图重写规则, 并作用于当前Petri网控制器, 使其快速、自动地重构为所求的新控制器. 所提出的Petri网控制器的设计与重构方法, 均从理论上保证了结果的正确性, 免校验. 仿真研究验证了方法的有效性. 相似文献
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在考虑动态部分重构及重构延时等特征的基础上,采用遗传算法及其与爬山算法的融合实现可重构系统软硬件任务的划分,并采用动态优先级调度算法进行划分结果的评价。实验表明,在可重构系统的资源约束等条件下,算法能够有效地实现应用任务图到可重构系统的时空映射。 相似文献
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针对阴性选择算法在解决实际问题中,易误判及自修复能力差的弱点,该文基于生物免疫系统内部学习优化机制以及工业领域中的可重构系统,提出了一种基于免疫重构的阴性选择算法.新算法将可重构系统的思想融入到阴性选择算法中,提出了重构串、重构模型与重构操作的概念与实现方法,以保证系统发生意外的时候能够及时恢复、重组.将算法应用于一个Web系统进行仿真实验,结果表明该算法是有效的. 相似文献
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《Computers & Industrial Engineering》2010,58(4):1431-1451
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. 相似文献