共查询到20条相似文献,搜索用时 15 毫秒
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本文针对多个企业共用一个加工厂加工某种产品这一类业务处理问题,提出了经由Petri网共享单链子网构成单链子网合成网的解决方案;给出了自由选择网(FC),非对称选择网(AC)的共享单链子网合成网为各自相应网的充分条件;提出了共享单链子网合成Petri网保持结构活性的条件;本文的结果可为Petri网系统合成的静态和动态性质的考察提供有效途径,具有宽广的应用前景. 相似文献
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Petri网是一种用网状图形表示系统模型的方法,它能够从组织结构、控制和管理的角度,精确描述系统中事件(变迁)之间的依赖(顺序)和不依赖(并发)关系。但传统的Petri网理论其不足之处在于:它的分析方法主要是可达树分析法和线性代数描述法。可达树分析法是针对某一个初始标识的,一个新的初始标识就意味着需要重新构造可达状态图;当系统存在较多 相似文献
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一种基于线性逻辑的时间Petri网推理方法 总被引:3,自引:0,他引:3
针对传统分析方法的不足 ,提出了时间 Petri网的线性逻辑表示和时间推理方法 .基于线性逻辑 ,定义了时间 Petri网中变迁之间的各种触发规则 ,在这些规则的基础上 ,提出了时间 Petri网运行行为的证明方法 ,此方法能清楚地分析时间 Petri网的运行行为和进行时间推理 . 相似文献
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A Survey of Petri Net Methods for Controlled Discrete Event Systems 总被引:14,自引:2,他引:14
This paper surveys recent research on the application of Petri net models to the analysis and synthesis of controllers for discrete event systems. Petri nets have been used extensively in applications such as automated manufacturing, and there exists a large body of tools for qualitative and quantitative analysis of Petri nets. The goal of Petri net research in discrete event systems is to exploit the structural properties of Petri net models in computationally efficient algorithms for computing controls. We present an overview of the various models and problems formulated in the literature focusing on two particular models, the controlled Petri nets and the labeled nets. We describe two basic approaches for controller synthesis, based on state feedback and event feedback. We also discuss two efficient techniques for the on-line computation of the control law, namely the linear integer programming approach which takes advantage of the linear structure of the Petri net state transition equation, and path-based algorithms which take advantage of the graphical structure of Petri net models. Extensions to timed models are briefly described. The paper concludes with a discussion of directions for future research. 相似文献
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模糊时间Petri网的时间推理及其在过程监测中的应用 总被引:2,自引:0,他引:2
针对传统分析方法的不足,提出用线性逻辑给出模糊时间Petri网描述和时间推理的方法。该方法能清楚地分析模糊时间Petri网的运行行为,具体例子说明了其在系统过程监测和诊断中的应用。 相似文献
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一种基于线性逻辑的Petri网分析方法 总被引:2,自引:0,他引:2
1 引言 Petri网是一种用网状图形表示系统模型的方法,能够从组织结构、控制和管理的角度,精确描述系统中事件(变迁)之间的依赖(顺序)和不依赖(并发)关系。Petri网理论提供了强大的分析方法,如不变量分析、系统性能分析(如活性)等以证明系统的正确性。近年来Petri网也被用来表示知识推理,例如用于诊断和监控,这就需要发展一种关于Petri网行为的推理主题。有些学者把经典逻辑和Petri网相结合,用Petri网表示产生式规则系统,网的框架代表基于产生式规则 相似文献
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为解决不确定条件下的故障诊断问题,在传统Petri网基础上,引入概率理论,提出了概率Petri网的概念;概率Petri网将事件发生的概率及其逻辑推理过程引入Petri网的设计及矩阵运算中,以反映事件转换过程中发生的可能性。针对概率Petri网特点,故障诊断模型的设计建立在根据简化样本集获取的诊断规则基础上,以避免复杂系统建模时出现的组合爆炸问题,诊断规则的获取可以有效推广故障诊断范围,使其不仅仅局限于样本集;同时,针对诊断规则的形式,定义并提出将诊断规则转换为标准基本规则序列,便于模型的程序化设计。通过旋转机械故障诊断的示例证明了这种方法的可行性与有效性。 相似文献
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并发程序的测试路径具有不可预测性,而Pctri网在描述并发方面具有其它系统模型无法比拟的优势。因此通过Petri网来产生并发程序的测试路径:对有并发程序的源代码构造的Petri网模型进行图形矩阵转换;按照一定的规则得出相应的独立段组;合并独立段组得出网的独立段群,此独立段群即为该并发程序的测试路径。实验证明,将Petri网用于并发程序测试用的例生成降低了测试难度,提高了测试效率。 相似文献
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针对柔性制造系统的设计和分析,提出了经由Petri网共享子网构成合成网的解决方案;研究了Petri网共享子网合成的动态性质保持问题,给出了合成网保持活性、有界性的一组充分条件;对一个柔性制造系统进行了设计和分析。本文的结果可为Petri网系统静态和动态性质的考察提供有效途径,为Petri网复杂大系统的分析提供重要手段,并特别适合于柔性制造系统的设计,具有一定的实用价值。 相似文献
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顾明 《计算机应用与软件》2005,22(11):26-27,114
本文提出了用BNF描述用例图的语法结构,分析了已有Petri技术对描述用例的局限性,给出了扩充的基于约束模块化Petri网的定义,并用一个实例说明了这些描述和定义的具体应用。 相似文献
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基于Petri网的FMS物流系统建模与仿真 总被引:3,自引:0,他引:3
在建立FMS物流系统Petri网模型的基础上,采用“映射”思想,将Petri网模型转化为物流系统的仿真程序,提出了库所映射为程序数据、变迁映射为程序函数、系统子网映射为FMS系统基本类的映射方法,通过实例仿真验证了软件程序与模型的一致性。 相似文献
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线性定常系统的Petri网解耦控制 总被引:1,自引:0,他引:1
将Petri网与现代控制理论相结合,应用于连续系统的性能分析如可控性、可观性和稳定性等已日益普遍,但Petri网应用于系统的解耦控制研究很少.提出了广义连续自控网系统的形式化定义,描述了线性定常系统的广义连续自控网系统模型并分析了广义连续自控网系统模型与状态空间描述的等效性.基于状态反馈动态解耦的基本原理,探讨了利用Petri网模型结构实现线性定常系统解耦控制的新方法.该方法采用图的遍历算法,可有效的判断系统的可解耦性以及实现解耦控制律,避免了传统解耦控制方法中计算所需的大量矩阵运算.最后给出了两个具体的应用实例. 相似文献
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Chao D.Y. Wang D.T. 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》1997,27(6):962-977
We present two aspects of knitting technique, the structural properties (especially the P- and T-invariants), and the synchronized choice net (a new class of Petri net), that are of both theoretical importance and practical uses to the verification of structural correctness of a Petri net or to detect the structural problem of a Petri net. This work first proves that the ordinary Petri nets synthesized with knitting technique are structurally bounded, consistent, conservative and safe (when each home place holds one token) using the well-known linear algebra approach. It also provides a procedure for finding P- and T-invariants for Petri net synthesized using the knitting technique. We present examples for P-invariants and show that we can synthesize Petri nets more general than the "asymmetric-choice nets". The algorithm for finding P-invariants of ordinary Petri nets is extended to find the P-invariants for a general Petri net synthesized with knitting technique and the arc-ratio rules. We present a new class of Petri nets, called synchronized choice nets, which are the largest set of Petri nets that can be covered by both T-components and P-components. An algorithm is proposed to find its T-components and the P-components, respectively. The complexity of this algorithm is also presented. The theory of synchronized choice nets has the potential to simplify that for free choice nets. 相似文献
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Xenofon D. Koutsoukos Kevin X. He Michael D. Lemmon Panos J. Antsaklis 《Discrete Event Dynamic Systems》1998,8(2):137-173
In this paper, timed Petri nets are used to model and control hybrid systems. Petri nets are used instead of finite automata primarily because of the advantages they offer in dealing with concurrency and complexity issues. A brief overview of existing results on hybrid systems that are based on Petri nets is first presented. A class of timed Petri nets named programmable timed Petri nets (PTPN) is then used to model hybrid systems. Using the PTPN, the stability and supervisory control of hybrid systems are addressed and efficient algorithms are introduced. In particular, we present sufficient conditions for the uniform ultimate boundness of hybrid systems composed of multiple linear time invariant plants which are switched between using a logical rule described by a Petri net. This paper also examines the supervisory control of a hybrid system in which the continuous state is transfered to a region of the state space in a way that respects safety specifications on the plant's discrete and continuous dynamics. 相似文献