共查询到19条相似文献,搜索用时 125 毫秒
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基于代理的可重构制造执行系统研究 总被引:3,自引:1,他引:3
为构建基于代理的可重构制造执行系统,将重构划分为实体重构和实体关系重构,提出了基于代理模型、角色模型和特征模型实现重构的方法,建立了基于代理模型、角色模型和特征模型的可重构制造执行系统,并通过工序任务外协实例说明了如何用上述方法实现重构。 相似文献
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模型驱动的制造执行系统可重构方法 总被引:2,自引:1,他引:1
基于组件的制造执行系统重构效率较低、管理困难,为此,提出了一种模型驱动的工程方法,从全生命周期的角度和较高的抽象层次规划实现制造执行系统的重构。引入可重构资产的概念,设计了可重构资产元模型,构建了面向制造执行系统重构的领域建模语言,以准确描述重构相关的需求和决策信息。介绍了重构过程中的模型转换与存储技术。最后,通过航天企业的实例验证了该可重构方法。 相似文献
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一种面向重构的业务过程模型 总被引:8,自引:2,他引:8
为提高业务模型的动态性和灵活性,提出了一种面向重构的业务过程模型RO-BPM。该模型由业务对象、业务操作、业务活动和业务过程等基本要素构成。在分析面向重构的业务过程模型应具备特征的基础上,定义业务对象的状态转换空间,根据业务活动导致业务对象发生的不同状态转换,将业务活动分为关键活动和辅助活动两类。业务过程即抽象为由关键活动构成的垂直子过程和由辅助活动构成的水平子过程的集成,以实现业务过程中频繁变化部分与相对稳定部分的分离。给出了RO-BPM中重构的分类和相应的实现机制,并通过实例验证了RO-BPM的有效性。 相似文献
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基于混合层次分析法的可重构制造系统重构方案选择 总被引:1,自引:0,他引:1
为解决可重构制造系统重构过程中构形选择的决策问题,建立了综合考虑定性和定量因素的构形评选层次结构模型,并提出了一种易于使判断矩阵满足一致性的混合层次分析决策方法.将混合层次分析法应用于一个实例,按步骤介绍了采用该方法选择重构方案的过程.实例分析表明,混合层次分析法简化了定性判断过程和定量因素的权重计算,为快速确定可重构制造系统重构方案提供了一种实用的方法. 相似文献
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可重构制造系统成本模型 总被引:2,自引:2,他引:2
分析了可重构制造系统的时间要素和成本构成,给出了成本构成模型。定义了节约因子αi、残留因子λi和时间价值因子σT,αi表示重构固定投资Ci和初始固定投资Co间的关系,λi表示固定投资未来价值与现价值间的折旧关系,σT表示未来投入成本的折现关系。分析了αi与Ci的关系,给出了5种生产需求下的Ci模型。最后建立了可重构制造系统近似成本模型,并进行了影响因素趋势分析。 相似文献
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为提高复杂产品装配规划的效率,针对当前装配模型不能有效支持结构重构的问题,分析了重构对装配模型中信息变更的影响,提出了一种基于装配关系元的装配关系模型表达方法,实现了装配模型中关系信息和层次信息的柔性关联,进一步给出了可重构装配模型的信息组织方法和存储机制。在引入相关重构算法概念的基础上,给出了装配模型信息动态管理维护算法,以保证装配模型信息在重构前后的完整性与一致性。通过产品实例说明了上述研究成果的可行性和实用性。 相似文献
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基于敏捷制造单元的车间动态重构 总被引:1,自引:0,他引:1
为适应现代车间的敏捷化需求,提出了一种基于敏捷制造单元的车间动态重构方法.车间的动态重构是一个优化制造资源,进而构造面向产品的敏捷制造单元,形成虚拟车间的过程,采用数学规划和模糊理论相结合的方法,优化制造资源.同时,提出了一种基于不完全知识和进化博弈理论的动态单元重构模型,它能够面向不确定的需求目标,采用自下而上和自上而下相结合的方法,快速生成稳定优化的可重构制造单元,从而实现敏捷车间的组织再设计.该模型求解采用协同进化算法,并通过实例,验证了该方法的可行性和有效性. 相似文献
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企业信息系统重构过程与重构性能评价 总被引:3,自引:1,他引:2
为适应业务环境的快速变化,企业信息系统需要频繁地重构。面对一个重构需求,有多种不同的重构方案可供选择。目前缺乏对重构方案的性能进行全面评估的手段以协助系统维护人员选择性能最优的重构方案。在对重构的性质进行归纳的基础上,形式化地描述了信息系统实施重构的过程,将重构过程抽象为重构需求在业务模型、软件模型、运行模型之间的映射。采用定量和定性相结合的方式,从复杂性、敏捷性和风险性3个方面,建立了一套刻画系统重构方案性能的评价指标体系,并给出了相应的评估过程。通过应用实例,说明了该研究结果可为企业信息系统重构过程的标准化和重构性能的改善提供重要的参考依据。 相似文献
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This paper studies a nonlinear receding horizon control guidance strategy for spacecraft formation reconfiguration on libration orbits in the Sun–Earth system. For comparison, a linear quadratic soft terminal control strategy is also considered for the same reconfiguration missions. A novel symplectic iterative numerical algorithm is proposed to obtain the optimal solution for the nonlinear receding horizon control strategy at each update instant. With the aid of the quasilinearization method, a high-efficiency structure-preserving symplectic method is introduced in the iterations, and the optimal control problem is replaced successfully by a series of sparse symmetrical linear equations. Several typical spacecraft formation reconfiguration missions including resizing, rotating and slewing reconfigurations and their combinations are numerically simulated to show the effectiveness of the nonlinear receding horizon guidance strategy based on the proposed symplectic algorithm. Through these simulations, the nonlinear receding horizon control strategy is shown to have obvious advantages in convergence and parameter sensitivity compared with a linear quadratic soft terminal control strategy. Monte Carlo stochastic simulations are used to test the robustness of the nonlinear receding horizon control guidance in dealing with measurement and execution errors. 相似文献
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敏捷制造单元动态重构研究 总被引:5,自引:2,他引:3
重构是实现敏捷制造单元的关键技术之一。本文首先给出了敏捷制造单元的定义 ,然后明确了敏捷制造单元重构的必要性 ,接着对敏捷制造单元重构问题进行了深入的分析 ,明确了重构问题的实质是制造资源的选择和组织问题 ,在此基础上提出了一种基于整数规划和排序聚类的重构算法 ,最后 ,用实例对算法加以验证 相似文献
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作为实现企业柔性生产的一种重要方式,重构对响应日益增强的个性化市场需求具有重要作用.针对模块化智能特性下生产系统的快速重构需求,围绕数字孪生驱动的模块化生产系统(DT-MPS)的架构及运行机制展开研究;在此基础上提出一种面向D T-M PS的重构方法,并重点围绕D T-M PS的建模方法和重构机制展开研究.以某企业模块... 相似文献
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Improved net rewriting system-based approach to model reconfiguration of reconfigurable manufacturing systems 总被引:1,自引:1,他引:0
Jun Li Xianzhong Dai Zhengda Meng 《The International Journal of Advanced Manufacturing Technology》2008,37(11-12):1168-1189
This work aims at presenting a method for rapidly reconfiguring Petri net (PN) models of reconfigurable manufacturing systems (RMS). We start with introducing the model of improved net rewriting systems (INRS), which supports dynamic structural changes in a PN model without losing its important behavioral properties, i.e., liveness, boundedness (or safeness), and reversibility. Based on INRS, the method for rapid reconfiguration of Petri net models for RMS is proposed and an implementation algorithm is designed as well. In our method, changes in a RMS configuration adjusted with production demands can be rapidly formalized into graph rewriting rules of an INRS called model reconfigurator whose underlying Petri net is the existing Petri net model. Subsequently, by applying these rewriting rules, the existing Petri net model can be reconfigured rapidly into a new one for the RMS with a new configuration. Validity of the resulting Petri net model can be guaranteed naturally throughout the whole reconfiguration process and thereby there is no need for verification. A case study is provided that demonstrates the reconfiguration process of a Petri net model for a reconfigurable manufacturing cell. The given case study shows that the proposed method is capable for reconfiguring PN models of RMS in a rapid and successive manner, without requiring verification. 相似文献
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Assessment of manufacturing systems reconfiguration smoothness 总被引:1,自引:0,他引:1
Ayman M. A. Youssef Hoda A. ElMaraghy 《The International Journal of Advanced Manufacturing Technology》2006,30(1-2):174-193
The effect of the configuration selection on the smoothness and easiness of manufacturing systems reconfiguration process cannot be neglected, especially when dealing with reconfigurable manufacturing systems (RMS). The term “reconfiguration smoothness” is introduced in this paper to address this issue. In order to evaluate the level of reconfiguration smoothness (RS), a metric was developed to provide a relative measure of the expected cost, time, and effort required to convert from one configuration to another. This metric is composed of three components representing different levels of reconfiguration, namely; market-level reconfiguration smoothness (TRS), system-level reconfiguration smoothness (SRS), and machine-level reconfiguration smoothness (MRS). Rules are introduced to guide the development of execution plans for system-level reconfiguration, which we call “reconfiguration planning”. These plans help reduce the physical effort of reconfiguring the system. A case study is presented to demonstrate the use of the developed metric followed by sensitivity analysis to show the effect of changing different metric parameters. The results show how the developed metric provides a powerful relative assessment tool for the transitional smoothness between a current configuration and a number of candidate feasible configurations for the next period. This can affect the configuration selection decisions at the beginning of each configuration period. 相似文献