一种软件特征模型扩展和演化分析方法

特征模型是面向特征的软件开发过程的重要概念和制品,该模型以特征为单位,刻画了领域产品的共性和可变性.在日趋频繁的软件演化过程中,保持特征模型的一致演化,对于支持高效的复用开发和按需配置至关重要.目前,大多数的研究是在需求层面进行共性和可变性分析,对特征模型的研究则集中在对共性和可变性的建模上.但是,由于特征变更在建模过程中存在"涟漪"效应,会导致新的共性和可变性演化.现有的分析方法还无法解决这个问题,会导致丢失一些潜在的产品共性,从而影响复用的效率.提出了一种特征模型扩展和演化分析方法.通过扩展特征关联关系和模型演化元操作,实现对特征变更"涟漪"效应的分析.发现潜在的产品共性,提出重构策略和半自动化的共性提取和特征重构支持方法.该方法还针对典型的配置冲突提出了冲突消解规则和策略.最后,通过案例分析验证了该方法的可用性和有效性.     

产品配置模型的演化与再配置

在分析产品配置的动态性、说明产品再配置的客观需求以及产品配置与产品再配置不同的基础上,提出了配置模型和配置单元演化的版本向上传播规则以及理想配置环境的三个不同层次,指出最理想的配置环境是能够描述配置模型的差异,并在不同时间对已配置产品进行再配置．最后给出了一个产品再配置的实现算法．     

网络化制造系统访问控制框架

建立SDACM对象模型的基础上,提出一个网络化制造系统的访问控制框架,研究了访问控制框架的工作流程以及框架与系统其他安全部件的关系。基于该框架开发的网络化制造原型系统在某企业应用中表明该框架能够满足网络化制造系统需求。     

云制造环境下个性化产品配置研究

在分析了云制造环境下的产品配置典型过程的基础上,总结了云制造环境下参与 者及制造资源组织的特点,包括产品配置过程需要兼顾不同参与方的利益,以及在产品配置求 解过程中需要覆盖不同制造服务实例的差异化属性的基础,提出了面向云制造的个性化产品配 置技术框架,阐述了面向产品配置的云服务模型、基于关联规则挖掘的产品初步配置以及基于 蚁群算法的产品完整配置 3 个关键问题的求解方法,为云制造环境下开展个性化产品配置提供 了一种新的思路。在模型设计及方案求解过程中,以轮式装载机产品配置作为示例进行了阐述, 验证了该方法的有效性和可行性。     

网络化工艺分工规划系统的研究

动态联盟企业面向复杂零件的工艺分工规划问题是网络化制造中的一个关键问题。针对该问题，提出了逻辑制造单元的概念，通过它在工艺分工规划和制造资源之间建立联系，研究了基于逻辑制造单元的制造资源能力建模、逻辑加工路线设计，以及面向逻辑加工路线的制造资源预配置和优化配置。最后针对复杂零件的制造，进行了基于制造资源优化配置的工艺分工规划系统体系结构设计，并给出了工作流程。     

一种面向服务的动态协同架构及其支撑平台

为了让面向服务的架构下的应用系统能够灵活地动态演化以适应底层因特网计算环境和用户需求的变化,该文提出了一种面向服务的动态协同架构．该架构引入内置的运行时体系结构对象来解耦系统中的各个服务构件,并通过该对象以体系结构的视角来重解释服务部件之间的引用和交互．这样就把体系结构这一抽象概念具体化为可直接操控的对象,从而可以利用面向对象程序设计语言的继承和多态等整套机制,导出一种面向体系结构的系统动态演化技术．为支持这一架构,设计并实现了一个支撑平台Artemis-ARC,为具有动态调整能力的面向服务应用系统的开发、运行和监控提供了一套可视化的集成环境．在此平台上还开发了一个简单的示例应用以展示动态调整的效果．     

可重构系统的演化修复机制

利用演化算法实现系统自修复是一种新的容错设计思路,但是演化是一个非常耗时的过程.已有的演化容错系统多属于静态演化,演化过程仅发生在系统设计阶段,系统在运行过程中不具有演化修复的能力.这类演化容错系统虽然可以避免演化耗时,但是只能修复已知错误,无法修复未知错误.针对上述问题,文中提出一种基于动态演化的修复机制,容错系统采用可重构系统和被检测系统的耦合设计方案.当被检测系统出现故障时,可重构系统通过系统演化实现在线自修复.为了减少演化耗时,系统根据错误类型采取不同措施:如果出现已知错误,系统直接在预置配置库中搜索修复配置;如果出现未知错误,则通过动态演化在线生成修复配置,并更新预置配置库.最后,将该容错设计方案用于典型电路的故障模式.实验结果表明,文中提出的演化修复机制提高了系统运行的实时可靠性,预置配置库设计减少了演化耗时.     

基于服务组合的可信软件动态演化机制

以基于服务组合的可信软件为研究对象,重点研究通过组合服务的动态演化机制保障网络化软件的可信性.首先,提出了一个合理性保持的演化操作集,避免复杂的验证过程,使得演化后的组合服务保持结构合理性;在此基础上,通过构造冗余路径的方式给出了一个面向可用性保障的组合服务演化方法;然后,针对组合服务动态演化过程中运行实例的处理,设计了一个组合服务演化中运行实例在线迁移算法,为正确实施演化提供支持;最后,设计实现了一个支持动态演化的组合服务执行引擎,并通过实验验证了所提出方法的有效性.     

一个面向服务的支持动态演化的软件模型

为了使面向服务的架构更适应动态演化的需求，提出了基于体系结构空间、支持动态演化的软件模型SASM．SASM是使用反射技术，通过具有因果相联的基层和元层来构造．基层由可运行的服务形成，元层是一个具备树形层次、层间存在求精关系的体系结构空间．该空间反映了需求的层次性，提供给用户不同抽象级别的视图和管理手段．通过对体系结构空间的观察，可获知系统的结构和行为信息．通过对体系结构空间的在线调整可实现对基层的修改进而实现系统的非预设动态演化，而空间中不同层次之间的求精关系保证了应用的完整性和演化的一致性．     

基于客户定制的产品配置

为了给客户提供一个直观和可视化的产品配置工具,研究了基于客户定制的产品配置模型,包括产品族功能模型、产品族装配模型以及产品配置知识的表达模型.利用该模型构建了一种面向客户基于Web的虚拟产品定制和展示环境,使得用户在该环境下可以提交需求目标,系统根据用户的需求进行配置,生成的产品三维实体模型可在浏览器中动态地观察和操作.     

Ontology-based reconfiguration agent for intelligent mechatronic systems in flexible manufacturing

This paper proposes a novel approach to achieving fast reconfiguration of modular manufacturing systems, based on an ontology-based reconfiguration agent. The agent uses ontological knowledge of the manufacturing environment for the purpose of reconfiguration without human intervention. The current mass customization era requires increased flexibility and agility in the manufacturing systems to adapt changes in manufacturing requirements and environments. Our configuration agent minimises the overheads of the current reconfiguration process by automating it. It infers facts about the manufacturing environment from the ontological knowledge model and then decides whether the current environment can support the given manufacturing requirements. This paper proposes the agent architecture enabling the integration between the high level planning with the distributed low level control compliant with the upcoming IEC 61499 function blocks standard.     

Rapid design and reconfiguration of Petri net models for reconfigurable manufacturing cells with improved net rewriting systems and activity diagrams

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.     

可重构制造系统监督控制器的自动重构

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.     

Automatic Reconfiguration of Petri Net Controllers for Reconfigurable Manufacturing Systems With an Improved Net Rewriting System-Based Approach

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.     

Systematic modeling and reusing of process knowledge for rapid process configuration

Rapid product development relies heavily on quick and reliable process planning and knowledge reuse. Process configuration borrows the principles of product configuration and applies them to process planning. It allows the reuse of hierarchical, historical and case-based manufacturing process knowledge to generate process plans efficiently and effectively. This paper presents a systematic knowledge model for manufacturing process cases. The model represents process knowledge at different levels of granularity and to facilitate process configuration. With this knowledge model the process knowledge is categorized into 6 levels: (i) core process skeletons, (ii) process networks, (iii) process routes, (iv) process segments, (v) processes/workplan, and (vi) operations/working step. Based on the systematic knowledge model, this paper also proposes an approach to achieve rapid process configuration by reusing the process knowledge and by performing the involved configuration rules so as to create an appropriate, reliable and effective process plan. The prototype for a graphical process planner based on this knowledge model is developed and an aerospace example is used to validate the proposed process knowledge model and process configuration.     

长时延NCS的结构特性与建模

研究网络控制系统的关键问题包括两个方面:控制算法和网络结构,其中网络结构决定了系统可靠性和稳定性,系统的实时性也取决于网络结构(包括拓扑结构和协议结构),建立网络结构模型是研究NCS的前提,文章介绍了典型的网络结构和结构抽象化描述方法,并分析了针对长时延的数学模型,该成果对研究NCS有很重要的意义。     

Decision-making method of reconfigurable manufacturing systems’ reconfiguration by a Gale-Shapley model

The companies need to rapid response to new product introduction, mix and demand changes to stay competitive. A reconfigurable manufacturing system can quickly react to changes in products and market. The control method to reconfigure the machines of a reconfigurable manufacturing system is crucial for the performance level. This paper proposes a reconfiguration decision-making method based on a Game-Theory algorithm, and in particular the Gale-Shapley model. A periodic review strategy is used to create two sets: one set of machine over-loaded and one set under-loaded. The Gale-Shapley model forms a coupled of over-loaded and under-loaded machines. The reconfiguration concerns the under-loaded machine of the coupled adding also the task performed by the over-loaded machine. This paper presents a simulation environment developed to evaluate the proposed method and highlight the main topics. The simulation results highlight how the game-theory approach developed improves all the performance measures with controlled number of machines’ reconfigurations.     

A simulation based methodology for evaluating product design and process configurations

The steady increase in the pace of innovation and new product development, market segmentation, shorter competitive life cycles, and rapid replacement or modification of design has led to an increasing demand for flexibility in manufacturing process configuration and operation. The lack of sufficient integration between product design and process capability often results in suboptimization of resource utilization and manufacturing system throughput. The effective design of manufacturing systems involves factors, both technical and qualitative in nature. This paper describes (1) a simulation based method for evaluating product design, material selection, and process configuration and capabilities, and (2) procedures for incorporating qualitative factors in the evaluation process.