共查询到17条相似文献,搜索用时 218 毫秒
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提出了一种用于可重构制造单元故障恢复的策略与方法, 允许故障发生时, 通过对用于正常操作控制的Petri网形式的监督控制器进行局部、临时性的修改, 实现故障的恢复. 首先, 提出改进的网重写系统, 可用于动态改变Petri网模型结构. 然后,提出了基于改进的网重写系统的故障恢复方法, 其中改进的网重写系统用于操作、引导Petri网监督控制器由错误状态进入正确状态. 故障恢复后监督控制器的结构与期望属性维持不变. 最后, 以实例演示了该故障恢复方法的应用, 证实了方法的有效性. 相似文献
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讨论了离散事件控制器快速综合与重构方面研究的意义以及存在的问题,介绍了基于改进的网重写系统的Petri网离散事件控制器快速综合与重构理论与方法的研究进展及其仿真系统开发。 相似文献
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可重写Petri网:位置可重写及性质分析 总被引:1,自引:0,他引:1
针对Petri网对动态系统重构形式化描述和建模能力的不足,提出了可重写Petri网和位置可重写Petri网的基本概念.分析了位置可重写Petri网保持有界性、保守性、可重复性及活性等性质.给出了位置可重写Petri网保持活性的一个充要条件.证明了共享合成Petri网是位置可重写Petri网的一个实例,建立了退化的位置可重写Petri网模拟共享合成Petri网的算法.所得结果能够为动态重构系统的Petri网形式化建模提供理论方法,为大规模动态分布式系统的形式化验证提供有效途径. 相似文献
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可重构制造系统的可重构控制器 总被引:10,自引:1,他引:10
可重构控制器是可重构制造系统的重要组成部分之一。该文提出了可重构控制器的体系结构。分析了实现可重构制造系统的可重构控制的方法。仿真研究表明可重构控制是实现可重构制造系统控制系统可重构的有效方法。 相似文献
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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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文中针对自重构机器人的重构问题提出了一种基于网络的分析方法.自重构模块机器人"AMOEBA-I"的9种不同构形组成了一个构形网络.机器人的每种构形被看成带有权值的有向构形网络中的一个节点.一种构形向另一种构形的转换可描述为一条非负值的有向路径.将图论应用于构形变化的分析,根据构形的拓扑信息相应定义了重构路径、可重构矩阵和路径矩阵.在此基础上,将图论中的算法应用于重构路径的计数和最佳重构路径的选择.数值分析与仿真实验结果验证了该方法的可行性.同时,该方法还可以用于其他自重构机器人的构形控制与自重构规划. 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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《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
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Sébastien Henry Eric Zamaï Mireille Jacomino 《Engineering Applications of Artificial Intelligence》2012,25(4):824-836
To respond rapidly to the highly volatile market, the reconfigurable manufacturing systems (RMS) have brought forward challenging issues. First of all there is a need to build a formal model of a manufacturing configuration. Second it has to be rather easy to derive the models associated to the manufacturing configuration changes (reconfiguration) from such an initial model. An off-line method of rapid design of an optimal logic control law (configuration) based on Petri net (PN) is presented in this paper. From a controlled system modeling point of view, the main characteristics of the level 1 of the CIM architecture are depicted. Subsequently, the formal tool used in the automated planning field is extended to provide a controlled system model. The concept of operation is structured in order to introduce the behavioral properties of the operations. A four-step method is then proposed to design a logic control law that satisfies several goals: reduction of the lead time, satisfaction of the work orders objectives, minimization of the time cycle. Finally, the proposed design method is illustrated on a manufacturing cell. 相似文献
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Reconfigurability is essential for semiconductor manufacturing systems to remain competitive. Reconfigurable systems avoid costly modifications required to change and adapt to changes in product, production and services. A fully automated, collaborative, and integrated while reconfigurable manufacturing system proves cost-effective in the long term and is a promising strategy for the semiconductor manufacturing industry. However, there is a lack of computing models to facilitate the design and development of control and management systems in a truly reconfigurable manner. This paper presents an innovative computing model for reconfigurable systems and controlled manufacturing processes while allowing for the integration of modern technologies to facilitate reconfiguration, such as radio frequency identification (RFID) and reconfigurable field programmable gate array (FPGA). Shop floor manufacturing activities are modeled as processes from a business perspective. A process-driven formal method that builds on prior research on virtual production lines is proposed for the formation of a reconfigurable cross-facility manufacturing system. The trajectory of the controlled manufacturing systems is optimized for on-demand production services. Reconfigurable process controllers are introduced in support of the essential system reconfigurability of future semiconductor manufacturing systems. Implementation of this approach is also presented. 相似文献
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Yang Cao Hoda A. ElMaraghy Ahmed Azab 《Journal of Intelligent and Robotic Systems》2007,50(4):419-439
The increased use of changeable characteristics in modern manufacturing and robotic systems and applications call for improved
system control design that offers some degree of reconfigurability. The need for control reconfiguration of robotic systems
arises due to some inherent characteristics of the robotic system, variations of robot parameters due to environmental changes,
major task changes typical in production changeover or manufacturing system reconfiguration, or geometry changes due to the
reconfiguration of modular manipulators. In this paper, a reconfigurable controller, the Supervisory Control Switching System
(SCSS), is proposed to meet the new on-line demands for changeability in robotic systems. The SCSS is capable of selecting
the most suitable controller for a particular task or situation, from separate controllers designed a priori. The applicability
and effectiveness of the developed switching control scheme have been illustrated through computer simulations of an AdeptOne
SCARA manipulators carrying out assembly tasks. 相似文献
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This paper deals with a problem of reconfigurable manufacturing systems (RMSs) design based on products specifications and reconfigurable machines capabilities. A reconfigurable manufacturing environment includes machines, tools, system layout, etc. Moreover, the machine can be reconfigured to meet the changing needs in terms of capacity and functionality, which means that the same machine can be modified in order to perform different tasks depending on the offered axes of motion in each configuration and the availability of tools. This problem is related to the selection of candidate reconfigurable machines among an available set, which will be then used to carry out a certain product based on the product characteristics. The selection of the machines considers two main objectives respectively the minimization of the total cost (production cost, reconfiguration cost, tool changing cost and tool using cost) and the total completion time. An adapted version of the non- dominated sorting genetic algorithm (NSGA-II) is proposed to solve the problem. To demonstrate the effectiveness of the proposed approach on RMS design problem, a numerical example is presented and the obtained results are discussed with suggested future research. 相似文献
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可重构制造系统的多Agent模型 总被引:1,自引:0,他引:1
论文在介绍可重构制造系统重构方法的基础上,给出了可重构制造系统多Agent模型的结构,并详细描述了基于该模型的可重构车间加工系统的重构算法,最后对重构算法进行仿真验证了该算法的可行性。 相似文献