以网络为中心的协同特征造型

在网络化同步协同设计环境中,如何实现CAD系统之间的实时数据交换和模型同步,成为协同几何造型的关键问题。文中提出了一种新的复制式协同特征造型方法,该方法将现有的特征造型技术与分布计算、网络通信技术相结合,通过简单的造型消息交换来实现增量式协同造型,可以较好地满足几何模型实时同步的需要,而且也部分地解决了异构CAD软件之间的数据交换问题;并详细地介绍了协同造型通信协议、对象引用机制、以及分布式协同造型系统。     

Maintaining constraints of UML models in distributed collaborative environments

Constraint maintenance plays an important role in keeping the integrity and validity of UML models in embedded software design. While constraint maintenance capabilities are reasonably adequate in existing UML modeling applications, little work has been done to address the distributed constraint maintenance issue in multi-user collaborative modeling environments. The nature of the issue is to maintain constraint consistently across distributed sites in a collaborative modeling environment in the face of concurrency. In this paper, we propose a novel solution to this issue, which can retain the effects of all concurrent modeling operations even though they may cause constraint violations. We further contribute a distributed constraint maintenance framework in which the solution is encapsulated as a generic engine that can be mounted in a variety of single-user UML modeling applications to support collaborative UML modeling and distributed constraint maintenance in embedded software design processes. This framework has been implemented in a prototype distributed collaborative UML modeling application CoRSA.     

A methodological approach for user interface development of collaborative applications: A case study

In the last few years, the production of systems which support learning and group work has been high. However, the design and development of these types of systems are difficult, mainly due to the multidisciplinarity involved. Furthermore, the Graphic User Interface (GUI) of an application is receiving greater attention, since it can be decisive in determining if the application is accepted or rejected by users. Model-based design is a widespread technique in the user interface development process. While reviewing approaches that deal with the modeling and design of user interfaces supporting collaborative tasks, we have detected that there is no proposal that links interactive and collaborative issues. We have introduced a methodological approach to solve this shortcoming. This approach is called CIAM (Collaborative Interactive Application Methodology) and it is composed of several stages in which conceptual models are created using CIAN (Collaborative Interactive Application Notation). These models start by modeling the organization in which the application will be used, as well as the tasks that must be supported. In the initial stages, the organization and the collaborative tasks are modeled using high-level specifications. In the following stages, the level of detail increases and, finally, the interaction between the individual users and the application is modeled using ConcurTaskTrees (CTT) notation. The interaction model acts as a bridge between the design and the implementation of the Graphic User Interface. In this paper we present our methodological approach and an example of applying this method for user interface design of collaborative and interactive applications.     

基于主模型的协同设计软件架构技术研究

运载火箭总体方案论证过程中,由于涉及专业多、专业间迭代交互频繁、设计方案多变等特点,容易造成多专业协同设计时版本与技术状态的不统一,需要研究针对运载火箭产品的通用建模方法,并开发相应的软件系统;基于统一数据源的协同设计理念,结合运载火箭总体设计与数据模型特点,通过定义基础信息模型、概念模型、参数模型、外部定义模型4种数据模型,提出了针对运载火箭产品的通用主模型构建方法;将此通用建模方法软件化,搭建了基于主模型的协同设计软件系统整体架构;此架构包含主模型管理系统、主模型建模工具及应用客户端三部分,实现了多专业协同设计过程中数据与版本的统一管理、技术状态一致性分析、谱系追踪、数据展示与应用等功能;该主模型建模工具与客户端软件系统的实现,为运载火箭的总体协同设计提供了工具支撑。     

基于多学科协同的起升设备设计系统

系统中集成了多个学科的仿真工具,支持分布式协同建模及协同仿真,其中采用了专家系统技术、自动参数化建模技术、数据库管理等技术.     

协同语义特征造型系统的研究

针对目前大多数造型系统都是面向单用户环境开发,且造型过程依赖于特征的创建历程,提出以基于细胞元的语义特征造型系统为基础,采用B/S和C/S相结合的方式构造协同框架,进行协同造型的方法。介绍了系统的逻辑设计及网络实现方法。系统可为多用户提供在互联网上同时编辑同一个特征模型的协同设计环境,设计人员可根据特征依赖图（FDG）得到所需的视图,由于网络传输的是造型操作命令,而不是完整的图像信息,因此网络负荷较小,响应速度快。     

Semantic Web based innovative design knowledge modeling for collaborative design

This paper describes a study about how to use the Semantic Web technologies for innovative design knowledge modeling in a multi-agent distributed design environment. Semantic Web based knowledge modeling for innovative design is proposed as prelude to the meaningful agent communication and knowledge reuse for collaborative work among multidisciplinary organizations. A model for innovative design is proposed at first, based on which a knowledge schema is brought forward. For sharing the design knowledge among an internet-based or distributed work team, even globally, A RDF-based knowledge model is presented to realize its representation on Semantic Web. A Semantic Web based repository for innovative design and its API for topper Semantic Web applications have been also constructed. The proposed knowledge modeling extends traditional product modeling with capabilities of innovative design, knowledge sharing and distributed problem solving, and is employed as a content language within the messages in the proposed multi-agent system architecture. The proposed approach is viewed as a promising knowledge management method that facilitates the implementation of computer supported cooperative work in innovative design of Semantic Web applications.     

网络协同三维零件设计技术及系统研究

结合当前三维零件设计协同工作的需求，基于三维参数化特征设计、特征编码技术和网络通信技术，研究开发了具有C/S体系结构的三维零件设计工具。利用泛命令的思想，将造型命令卉分为网络命令和本地命令，大大减少了网络中传递的数据量；通过组织相应的网络数据结构，较好地实现了网络环境下零件级产品协同参数化造型设计。     

支持参数和公差设计的多学科协同建模

分析了多学科协同设计的耦合关系，提出支持参数和公差设计的多学科协同建模．首先。获得设计初始阶段各领域专家给出的约束条件和设计变量的大致范围；然后，抽取所有领域中在参数和公差设计阶段的耦合参数和相关约束；最后，构建产品的变动约束网络模型．在多学科协同建模中，考虑了不等式约束条件的转化、微分方程形式约束的转化、参数和公差的综合，以及与三维CAD系统的集成；为进一步实现参数和公差协同求解奠定了基础。     

协同三维几何建模动态访问技术研究*

为解决协同设计过程中几何模型的动态访问问题,提出一种基于Web的协同设计环境下三维几何建模动态访问的分布式体系结构、异类CAD系统之间的动态数据交换组织模式。同时,提出一种面向对象的基于优先权限的乐观并发控制协议,保证模型动态访问在各站点操作的执行结果之间的一致性。在这些技术的共同作用下实现了协同三维几何建模动态访问技术,并通过具体实例验证了该技术的可行性。     

Role-based viewing envelopes for information protection in collaborative modeling

Information security and assurance are new frontiers for collaborative design. In this context, information assurance (IA) refers to methodologies to protect engineering information by ensuring its availability, confidentiality, integrity, non-repudiation, authentication, access control, etc. In collaborative design, IA techniques are needed to protect intellectual property, establish security privileges and create ‘need to know’ protections on critical features. Aside from 3D watermarking, research on how to provide IA to distributed collaborative engineering teams is largely non-existent.This paper provides a framework for IA within collaborative design. It is based on a technique we call role-based viewing, which is achieved through integration of multi-resolution geometry and security models. In this way, 3D models are geometrically partitioned, and the partitioning is used to create multi-resolution mesh hierarchies that obscure, obfuscate, or remove sensitive material from the view of users without appropriate permissions. This approach is the basis for our prototype system FACADE (the Framework for Accesscontrol in Computer-Aided Design Environments), a synchronous multi-user collaborative modeling environment. In FACADE, groups of users work in a shared 3D modeling environment in which each user's viewing and modeling privileges are managed by a central access control mechanism. In this manner, individual users see only the data they are allowed to see, at the level of detail they are permitted to see it.     

基于特征重排的协同设计系统研究

随着协同虚拟环境概念的提出,使得多用户之间基于特征的建模设计成为可能并迫切需要一个有效、灵活并支持异地分布的多用户协同工作的系统。在文献[2]提出的特征重排思想的基础上对协同设计系统进行研究,提出了一个基于特征重排的协同设计应用系统模型,详细探讨了模型系统的结构,重点阐述了该系统模型中当用户不按照初始设计顺序提交特征造型信息时,服务器如何依据特征重排的思想对特征进行布尔操作保持与原始造型一致,这对于提高协同设计的效率有重要意义。     

基于网络的协同CAD特征建模技术研究

探讨了协同工作模式和建模的需求，论述了一种结合C／S和B／S结构优势的三维CAD协同建模系统的结构和实现，通过对三维以数化特征技术，网络通信技术和特征编码技术等关键技术的研究，初步实现了局域网环境下零件级产品协同参数化造型设计和Internet上的模型信息发布。     

A method for topological entity correspondence in a replicated collaborative CAD system

In order to utilize the potential advantages of replicated collaborative CAD system to support natural, free, fast and less-constrained multi-user human-to-human interaction, a local-locking mechanism, which can provide fast modeling response, is adopted as concurrency control mechanism for a replicated on-line collaborative CAD system. A human–human interactive modeling is achieved by immediate local execution of modeling operations and exchange of modeling operations across all collaborative sites real-time. In particular, an approach to achieve topological entity correspondence across collaborative sites during modeling procedure, which is critical to guarantee the correctness and consistency of collaborative modeling result, is proposed. A prototype system based on the ACIS geometric modeling kernel is implemented to verify availability of the proposed solution.     

面向定制化牙科产品的协同设计系统的研究

为了快速设计和制造定制化牙科产品,结合牙科产品的特点,分析了定制化牙科产品协同设计系统中各组织间的协同作用、产品协同设计过程以及协同设计系统的结构;以定制化托槽为例,研究了结合托槽设计及选区激光熔化快速成型的协同设计系统的产品设计制造流程,运用统一建模语言建立了定制化托槽的协同设计过程.实例表明,采用该系统,牙科产品开发商与牙科医生协作实现快速设计并制造定制化产品.     

支持协同商品设计活动的动态联盟系统研究

文章基于创新的协同商品设计思路,从产品概念设计阶段出发,对其支持系统——协同商品动态设计联盟进行了系统论述。介绍了协同商品动态设计联盟知识体系,提出了动态联盟快速生长的思想,研究了联盟建模过程,给出了实现联盟成员快速评价的两个基本条件——联盟成员历史行为库和开放式接入方法,最后通过系统原型的开发验证了所述方法的有效性。     

基于特征重排的协同设计系统研究

随着协同虚拟环境概念的提出，使得多用户之间基于特征的建模设计成为可能并迫切需要一个有效、灵活并支持异地分布的多用户协同工作的系统。在文献[2]提出的特征重排思想的基础上对协同设计系统进行研究，提出了一个基于特征重排的协同设计应用系统模型，详细探讨了模型系统的结构，重点阐述了该系统模型中当用户不按照初始设计顺序提交特征造型信息时，服务器如何依据特征重排的思想对特征进行布尔操作保持与原始造型一致，这对于提高协同设计的效率有重要意义。     

复杂产品协同设计中数据建模与驱动方法

针对在传统基于工作流的协同设计中,不同专业设计人员交流和任务协调困难导致产品设计效率低下的问题,提出复杂产品"一元三层"数据模型和基于数据驱动的复杂产品协同设计技术。首先采用多维多粒度的数据建模和本体描述方法完成了对复杂产品的信息建模,然后采用基于本体的语义检索技术完成协同设计过程任务的数据订阅,最后实现基于数据订阅/发布的复杂产品任务协同技术。实验结果表明,基于数据驱动的复杂产品协同设计技术解决了传统协同设计过程中不同专业设计人员之间交流与任务协调的困难,实现复杂产品协同设计过程的螺旋式上升,从而提高了产品设计效率。     

协同特征造型系统CFM的设计

在已有研究的基础上,设计了一个基于标识的复制式协同特征造型系统。设计和实现了基于消息协议XMP的分布式消息系统,在消息系统的基础上,通过在特征造型客户端及服务器之间传送各种XML格式的消息,解决了协同设计中的数据交换、协同设计、模型一致性及快速响应问题。