基于基本信标的自动制造系统活性控制器设计
发布时间：2018-12-12 03:45
【摘要】：柔性制造系统是由计算机数控机床和物料传输系统构成的可以高效地生产中小批量不同产品的自动制造系统。死锁是设计柔性制造系统控制器时必须考虑和解决的问题。在有些情况下,死锁造成的局部或整体的系统停顿并不单纯地降低生产率,更可能造成重大经济损失甚至灾难性后果。因此,柔性制造系统中死锁的描述、分析及控制对系统控制的实现和运行至关重要。目前,基于Petri网的自动制造系统死锁处理方法大致分为三种策略：死锁检测与恢复、死锁避免和死锁预防。死锁检测与恢复策略是一种在线检测及恢复死锁状态的机制,一旦检测到死锁发生,便通过在线策略重新分配共享资源使系统恢复到正常状态。死锁避免是一种在线资源分配机制,通过在线策略合理分配系统资源使系统不能进入死锁状态。死锁预防策略通过离线机制控制系统对共享资源的使用请求,保证死锁不会发生。 一般地,死锁预防可以通过为网系统添加控制器来预防死锁发生。衡量Petri网活性控制器的性能指标主要分为结构复杂性、计算复杂性及行为许可性三个方面。信标作为表征Petri网结构特性的重要对象,与Petril网系统的死锁密切相关,这一点在普通Petri网和一般Petri网中均成立。为了获得最大许可行为的、结构简单的及计算复杂度较低的Petri网活性控制器,许多研究者提出了大量基于信标分析控制技术的死锁控制策略。因此,Petri网中信标的提取及分析方法是系统死锁控制中一种非常重要的技术手段。由于Petri网信标求解的固有复杂性,任何依赖完全枚举信标的死锁预防算法在理论上必然为指数复杂度。本文立足于Petri网的信标分析及基本信标提取技术,研究柔性制造系统的活性Petri网控制器设计方法。主要完成以下工作： 1.行为许可性是衡量Petri网活性控制器性能的重要指标之一。针对一类普通Petri网-S3PR网系统,提出了关于初始标识的S3PR网最大许可行为活性控制器存在性的充分条件。基于基本信标理论,提出了最大许可行为活性监督控制器存在性的判定算法。该算法基于基本信标与信标复合的计算,关于网规模为多项式复杂度。在S3PR网中,一定存在可以得到最大许可行为的活性控制器的初始标识。同时,结合给出的充分条件,提出了S3PR网最大许可行为活性控制器迭代设计算法。在每一步迭代中,该算法运用混合整数规划的死锁检测方法获得一个信标并加以控制。大量实例验证了该方法的有效性。本研究可视为对基本信标理论的进一步应用。 2.在柔性制造系统中,基于信标的死锁控制往往面临计算复杂性和结构复杂性问题。为了降低控制器的结构复杂度,基本信标理论最初成功地应用于普通Petri网中。但考虑到在一般Petri网系统中资源分配具有更为复杂的情况,基本信标的选取及其可控性的分析仍需要进一步改进。为了改进基本信标在一般Petri网中的扩展应用,针对一类一般Petri网-WS3PR网系统,首次引入了扩展信标的概念。扩展信标是一个能够反映其原始信标中资源复杂使用的多集。考虑WS3PR网系统的拓扑结构和权值信息,提出扩展基本信标概念,并给出了改进的基本信标定义,通过该定义可以得到一组与系统结构紧密相关的基本信标集合。同时,基于图论,在WS3PR网中引入初始资源加权有向图,并提出了结构同构网系统的概念。对于结构同构的不同网系统,可以共用一组基本信标。 3.定义了一类一般Petri网-GLS3PR网系统,该网系统可以较好地建模柔性制造系统,同时具有便于分析的结构特性。针对GLS3PR网提出了一种高效的严格极小信标和基本信标提取方法。通过结构分析引入了扩展信标概念,并由此改进了基本信标定义。基于图论,在普通网中可利用初始资源有向图来计算所有的严格极小信标。本文针对GLS3PR网系统,引入初始资源加权有向图。在满足一定的约束条件下,从初始资源加权有向图中求取一组约束导出子图。考虑GLS3PR网结构,利用这些子图,建立了提取所有严格极小信标及其扩展信标的方法。此外,根据信标和约束导出子图之间的关系,给出了扩展基本信标个数的上确界。大量实验结果表明,通过该方法获得的基本信标结构紧凑且更适用于GLS3PR网系统。 4.为了改善活性控制器的结构复杂性和行为许可性,针对一类一般Petri网-S4PR网系统,提出一种有效的死锁预防策略。通过分析一般Petri网系统发现,一般Petri网系统的死锁可以通过非充分标识信标来反映,而基本信标理论的提出为设计结构简单的活性控制器提供了可行方向。由此,在S4PR网系统中将非充分标识信标划分为基本信标和从属信标,从属信标的可控性可以通过对其基本信标的合理控制来实现。为了获得一组结构紧凑且适用的基本信标集合,通过结构分析在S4PR网系统中引入扩展基本信标概念,然后结合松弛的信标最大可控性条件来满足信标的可控性。该方法仅对基本信标添加控制器,即可获得活性受控网系统。此外,通过设计控制库所输出弧撤弧算法来获得许可行为更优的活性控制器。
[Abstract]:The flexible manufacturing system is an automatic manufacturing system which is composed of a computer numerical control machine tool and a material transmission system, which can efficiently produce small and small batches of different products. Deadlock is a problem that must be taken into account and solved when designing a flexible manufacturing system controller. In some cases, the local or global system pause caused by the deadlocks does not simply reduce the productivity, and may result in significant economic losses and even catastrophic consequences. Therefore, the description, analysis and control of the deadlock in the flexible manufacturing system is of great importance to the realization and operation of system control. At present, the deadlock processing method of automatic manufacturing system based on Petri net is divided into three strategies: deadlock detection and recovery, deadlock avoidance and deadlock prevention. The deadlock detection and recovery strategy is a mechanism of on-line detection and recovery of the deadlock state. Once the deadlock has been detected, the system is re-allocated to the normal state through the on-line policy reallocating the shared resource. The deadlock avoidance is an on-line resource allocation mechanism, and the system resources are reasonably distributed through the online policy so that the system can not enter the deadlock state. The deadlock prevention strategy guarantees the use request of the shared resource by the off-line mechanism control system, and ensures that the deadlock does not occur. In general, deadlock prevention can prevent deadlocks by adding a controller to the network system The performance index of the Petri net active controller is mainly divided into three parties: structure complexity, computational complexity and behavior licensing. As an important object for characterizing the structure of the Petri net, the beacon is closely related to the deadlock of the Petri net system. In order to obtain the maximum permissible behavior, the structure is simple and the computational complexity is lower, and many researchers have put forward a lot of deadlock control methods based on the beacon analysis control technology. Therefore, the extraction and analysis method of the object of the Petri net is a very important technical hand in the system deadlock control segment. Because of the inherent complexity of the Petri net beacon solution, any deadlock prevention algorithm that relies on the full enumeration of the beacon must theoretically be complex in theory In this paper, based on the beacon analysis of the Petri net and the basic beacon extraction technology, the design party of the active Petri net controller of the flexible manufacturing system is studied. Method. The following work is mainly completed 1. The behavior permissibility is an important means to measure the performance of the Petri net's active controller. In this paper, for a class of common Petri net-S3PR network system, the existence of the maximum permissible behavior controller of the S3PR network with initial identification is proposed. In this paper, based on the basic beacon theory, the existence of the maximum permissible behavior monitoring controller is put forward. The algorithm is based on the calculation of the basic beacon and the beacon composite, and the network size is a polynomial. Complexity. In the S3PR network, there must be the beginning of the active controller which can get the maximum permissible behavior. The initial identification is given. At the same time, the iterative setup of the maximum allowable behavior controller of the S3PR network is put forward in combination with the sufficient conditions. in each iteration, the algorithm uses a deadlock detection method of mixed integer programming to obtain a beacon and add to control. A large number of instances validate the method Effectiveness. This study can be considered as an entry to the basic beacon theory Step application. 2. In the flexible manufacturing system, the deadlock control based on the beacon is often faced with the computational complexity and structure complexity problem. In order to reduce the structural complexity of the controller, the basic beacon theory is successfully applied to the ordinary Pe in that tri-network, the analysis of the selection of basic beacon and its controllability still need to be given in view of the more complex resource allocation in the general Petri net system In order to improve the extended application of the basic beacon in the general Petri net, the extension of the general Petri net-WS3PR network system is introduced for the first time. the concept of a beacon. The extended beacon is a complex that can reflect the resources in its original beacon Considering the topological structure and weight information of the WS3PR network system, the concept of extended basic beacon is put forward, and the improved basic beacon definition is given. At the same time, based on the graph theory, the initial resource weighted digraph is introduced in the WS3PR network, and the structure isomorphic network is proposed. The concept of a system. For different network systems with a homogeneous structure, one can share one. Group basic beacon. 3. A class of general Petri net-GLS3PR network system is defined, which can be used to model the flexible manufacturing system. The structure characteristics of the analysis are analyzed. An efficient and strict minimum beacon and base are proposed for GLS3PR network. The method for extracting the beacon comprises the following steps of: introducing an extended beacon concept through a structure analysis, Basic beacon definition. Based on graph theory, the initial resource digraph can be used to calculate all the basic beacon. The system of GLS3PR is introduced in this paper. The resource-weighted digraph is obtained from the initial resource-weighted digraph under certain constraint conditions. Group-constrained derived sub-graphs. Taking into account the GLS3PR network structure, using these subgraphs, all strictly minimal beacons are established and all the strictly minimal beacons are extracted. The method of expanding the beacon. In addition, according to the relation between the beacon and the constraint-derived sub-graph, the extended basic signal is given. A large number of experimental results show that the basic beacon obtained by this method is compact and more suitable for GL The S3PR network system. 4. In order to improve the structure complexity and behavior permissibility of the active controller, a kind of general Petri net-S4PR network system is put forward. In this paper, by analyzing the common Petri net system, the deadlock of the general Petri net system can be reflected by the non-sufficient identification of the beacon, while the basic beacon theory is the active control with simple design structure. in that S4PR network system, the non-fully identify beacon is divided into a base beacon and a slave beacon, and the controllability of the slave beacon can be in ord to obtain a set of basic beacon which are compact and suitable, an extended basic beacon concept is introduced in a S4PR network system through a structure analysis, the method only adds a controller to the basic beacon, in addition, that license line is obtain by the arc-back-arc algorithm output by the design control library,
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH165;TP273
本文编号：2373843
[Abstract]:The flexible manufacturing system is an automatic manufacturing system which is composed of a computer numerical control machine tool and a material transmission system, which can efficiently produce small and small batches of different products. Deadlock is a problem that must be taken into account and solved when designing a flexible manufacturing system controller. In some cases, the local or global system pause caused by the deadlocks does not simply reduce the productivity, and may result in significant economic losses and even catastrophic consequences. Therefore, the description, analysis and control of the deadlock in the flexible manufacturing system is of great importance to the realization and operation of system control. At present, the deadlock processing method of automatic manufacturing system based on Petri net is divided into three strategies: deadlock detection and recovery, deadlock avoidance and deadlock prevention. The deadlock detection and recovery strategy is a mechanism of on-line detection and recovery of the deadlock state. Once the deadlock has been detected, the system is re-allocated to the normal state through the on-line policy reallocating the shared resource. The deadlock avoidance is an on-line resource allocation mechanism, and the system resources are reasonably distributed through the online policy so that the system can not enter the deadlock state. The deadlock prevention strategy guarantees the use request of the shared resource by the off-line mechanism control system, and ensures that the deadlock does not occur. In general, deadlock prevention can prevent deadlocks by adding a controller to the network system The performance index of the Petri net active controller is mainly divided into three parties: structure complexity, computational complexity and behavior licensing. As an important object for characterizing the structure of the Petri net, the beacon is closely related to the deadlock of the Petri net system. In order to obtain the maximum permissible behavior, the structure is simple and the computational complexity is lower, and many researchers have put forward a lot of deadlock control methods based on the beacon analysis control technology. Therefore, the extraction and analysis method of the object of the Petri net is a very important technical hand in the system deadlock control segment. Because of the inherent complexity of the Petri net beacon solution, any deadlock prevention algorithm that relies on the full enumeration of the beacon must theoretically be complex in theory In this paper, based on the beacon analysis of the Petri net and the basic beacon extraction technology, the design party of the active Petri net controller of the flexible manufacturing system is studied. Method. The following work is mainly completed 1. The behavior permissibility is an important means to measure the performance of the Petri net's active controller. In this paper, for a class of common Petri net-S3PR network system, the existence of the maximum permissible behavior controller of the S3PR network with initial identification is proposed. In this paper, based on the basic beacon theory, the existence of the maximum permissible behavior monitoring controller is put forward. The algorithm is based on the calculation of the basic beacon and the beacon composite, and the network size is a polynomial. Complexity. In the S3PR network, there must be the beginning of the active controller which can get the maximum permissible behavior. The initial identification is given. At the same time, the iterative setup of the maximum allowable behavior controller of the S3PR network is put forward in combination with the sufficient conditions. in each iteration, the algorithm uses a deadlock detection method of mixed integer programming to obtain a beacon and add to control. A large number of instances validate the method Effectiveness. This study can be considered as an entry to the basic beacon theory Step application. 2. In the flexible manufacturing system, the deadlock control based on the beacon is often faced with the computational complexity and structure complexity problem. In order to reduce the structural complexity of the controller, the basic beacon theory is successfully applied to the ordinary Pe in that tri-network, the analysis of the selection of basic beacon and its controllability still need to be given in view of the more complex resource allocation in the general Petri net system In order to improve the extended application of the basic beacon in the general Petri net, the extension of the general Petri net-WS3PR network system is introduced for the first time. the concept of a beacon. The extended beacon is a complex that can reflect the resources in its original beacon Considering the topological structure and weight information of the WS3PR network system, the concept of extended basic beacon is put forward, and the improved basic beacon definition is given. At the same time, based on the graph theory, the initial resource weighted digraph is introduced in the WS3PR network, and the structure isomorphic network is proposed. The concept of a system. For different network systems with a homogeneous structure, one can share one. Group basic beacon. 3. A class of general Petri net-GLS3PR network system is defined, which can be used to model the flexible manufacturing system. The structure characteristics of the analysis are analyzed. An efficient and strict minimum beacon and base are proposed for GLS3PR network. The method for extracting the beacon comprises the following steps of: introducing an extended beacon concept through a structure analysis, Basic beacon definition. Based on graph theory, the initial resource digraph can be used to calculate all the basic beacon. The system of GLS3PR is introduced in this paper. The resource-weighted digraph is obtained from the initial resource-weighted digraph under certain constraint conditions. Group-constrained derived sub-graphs. Taking into account the GLS3PR network structure, using these subgraphs, all strictly minimal beacons are established and all the strictly minimal beacons are extracted. The method of expanding the beacon. In addition, according to the relation between the beacon and the constraint-derived sub-graph, the extended basic signal is given. A large number of experimental results show that the basic beacon obtained by this method is compact and more suitable for GL The S3PR network system. 4. In order to improve the structure complexity and behavior permissibility of the active controller, a kind of general Petri net-S4PR network system is put forward. In this paper, by analyzing the common Petri net system, the deadlock of the general Petri net system can be reflected by the non-sufficient identification of the beacon, while the basic beacon theory is the active control with simple design structure. in that S4PR network system, the non-fully identify beacon is divided into a base beacon and a slave beacon, and the controllability of the slave beacon can be in ord to obtain a set of basic beacon which are compact and suitable, an extended basic beacon concept is introduced in a S4PR network system through a structure analysis, the method only adds a controller to the basic beacon, in addition, that license line is obtain by the arc-back-arc algorithm output by the design control library,
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TH165;TP273
【参考文献】
相关期刊论文 前1条
1 李志武,王安荣;基于Petri网的柔性制造系统一种预防死锁方法(英文)[J];自动化学报;2003年05期
，本文编号：2373843
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