装配序列约束下的飞机虚拟维修过程建模仿真

针对当前飞机虚拟维修过程模型固化,对维修复杂行为关系缺乏考虑,无法满足学员多样性实训需求的现状,充分考虑了飞机系统的复杂度、学员操作的不规范性和随机性等因素,依据各维修装配序列间的优先约束关系,构建了优先约束矩阵,进而定义了优先约束时间有色Petri网模型。在系统梳理维修实体及其维修操作行为的基础上,提出了虚拟维修实体操作元模型和元模型融合下的过程建模,阐述了基于优先约束时间有色Petri网的动态虚拟维修过程实现方法。最后,以A320飞机加油活门的某一个随机拆卸过程为例,进行建模仿真,验证了模型的有效性。     

基于过程模型的动态工作流的研究

为了使工作流系统在执行过程中支持动态可变性,分析了工作流过程定义阶段及流程执行阶段的动态性特征,提出了基于过程模型的动态工作流,并在动态工作流元模型中定义相应的操作原语和操作规则,采用动态建模的方法实现了工作流模型的动态演变.     

支持自顶向下设计的产品功能建模技术

自顶向下的设计模式符合一般的设计规律，而以几何建模技术为主的各种CAD系统难以真正地对这一过程提供支持。本文介绍了一种基于功能单元和功能特征的产品功能模型，它能够表达产品的功能结构和功能关系，并建立对零件形状特征的功能约束。功能建模系统同基于特征的产品建模系统相连接，能够实现自顶向下的产品设计。     

联机分析处理中的非规则维建模

预聚集技术通过预先计算并保存原始数据上的查询结果以实现联机分析处理系统的快速查询响应能力．然而，在实际应用中，许多非规则维的结构难以使用传统多维模型进行建模，从而影响了预聚集技术的使用．为此，基于子级别到父级别的部分映射定义级别之间的部分序关系，进而提出了一个支持非覆盖、非映上等非规则雏中维级别关系建模的维模型．同时，在维模型基础上，定义了支持非规则维的立方体模型以及典型的联机分析处理操作．多维模型与关系模式的转换定义和实例分析证明了该多维模型可以实现对各种非规则维的建模支持，保证了预聚集技术在联机分析处理中的使用．     

支持自顶向下设计的产品功能建模技术

自顶向上的设计模式符合一般的设计规律，面对几何建模技术为主的各种ＣＡＤ系统难以真正地对这一过程提供支持本文介绍了一种基于功能单元和功能特征的产品功能模型。它能够表达产品的功能结构和功能关系，并建立了对零件形状特征的功能约束。功能建模系统 基于特征的产品建模系统相连接，能够实现自顶向下的产品设计 。     

支持实体数控铣削仿真验证的Cuboid-Array模型的研究

研究了Z-Buffer，Dexel和Ray-representation建模思想和方法，提出Cuboid-array的实体近似建模方法．采用基于设计模型的实体数控仿真验证技术，以Cuboid-array表示干涉元素集合体，提出基于B-rep和Cuboid-array的双体建模的近似实体数控仿真验证技术．给出了基于Cuboid-array的数控仿真验证算法，研制了基于双体建模和双体显示的数控仿真验证实验系统，实现了面向过程和结果的实体数控仿真的集成、面向实体数控仿真和实体数控验证的集成，并给出了实验用例．     

一种基于状态机的形式化验证技术

状态机作为一种描述实体间交互或者单个实体行为的建模图,它具有丰富的直观图形化的符号。在许多模型的设计阶段都采用它来建模。但是因为缺乏精确完整的语义定义,给它的形式化验证带来困难。本文给出一种形式化操作语义,并概述基于形式化规则的验证技术。     

基于虚拟原型的产品建模与特征生成方法研究

本文着重研究虚拟原型技术中的两个关键问题 :产品概念设计建模、虚拟特征生成及其主要实现技术。给出了相关概念的定义与解释 ,深入分析了基于虚拟原型的概念设计需求和特点 ,介绍了基于虚拟原型的概念设计描述方法和设计过程。在分析虚拟原型的特征分类以及概念设计过程特点的基础上 ,提出一种基于虚拟原型的概念设计描述模型Ｖ ｄｅｓＭｏｄｅｌ,其核心特点是采用产品视图模型描述设计对象 ,将虚拟特征概念融入视图模型中 ,并采用可扩展“三维实体 约束图”描述设计对象之间的约束关系。Ｖ ｄｅｓＭｏｄｅｌ能有效地支持基于虚拟原型的…     

一种基于状态机的形式化验证技术

状态机作为一种描述实体间交互或者单个实体行为的建模图,它具有丰富的直观图形化的符号。在许多模型的设计阶段都采用它来建模。但是因为缺乏精确完整的语义定义,给它的形式化验证带来困难。本文给出一种形式化操作语义,并概述基于形式化规则的验证技术。     

基于特征技术的变型设计与产品装配建模

论述了特征技术在产品变型设计中的应用，讨论了装配模型及其建模技术。把特征技术变形设计理论以及实例推理技术应用于产品的装配模型的建模中。并给出了具体的建模方法。     

Reverse innovative design — an integrated product design methodology

Today’s product designer is being asked to develop high quality, innovative products at an ever increasing pace. To meet this need, an intensive search is underway for advanced design methodologies that facilitate the acquisition of design knowledge and creative ideas for later reuse. Additionally, designers are embracing a wide range of 3D digital design applications, such as 3D digitization, 3D CAD and CAID, reverse engineering (RE), CAE analysis and rapid prototyping (RP). In this paper, we propose a reverse engineering innovative design methodology called Reverse Innovative Design (RID). The RID methodology facilitates design and knowledge reuse by leveraging 3D digital design applications. The core of our RID methodology is the definition and construction of feature-based parametric solid models from scanned data. The solid model is constructed with feature data to allow for design modification and iteration. Such a construction is well suited for downstream analysis and rapid prototyping. In this paper, we will review the commercial availability and technological developments of some relevant 3D digital design applications. We will then introduce three RE modelling strategies: an autosurfacing strategy for organic shapes; a solid modelling strategy with feature recognition and surface fitting for analytical models; and a curve-based modelling strategy for accurate reverse modelling. Freeform shapes are appearing with more frequency in product development. Since their “natural” parameters are hard to define and extract, we propose construction of a feature skeleton based upon industrial or regional standards or by user interaction. Global and local product definition parameters are then linked to the feature skeleton. Design modification is performed by solving a constrained optimization problem. A RID platform has been developed and the main RE strategies and core algorithms have been integrated into SolidWorks as an add-in product called ScanTo3D. We will use this system to demonstrate our RID methodology on a collection of innovative consumer product design examples.     

Introducing blending operations in feature models

We describe the implementation of a blending facility in the context of a feature modelling system where solid and feature-based modelling operations can be utilized in parallel during the design process of a part. The definition of blends can be done in a graphical user interface by selecting edges to be blended. Feature recognition of blends facilitates the definition process of blends. Alternatively, a special feature editor can be used to add blends to the feature model. The particular implementation style chosen gives rise to aflexible and easy-to-use modelling tool.     

基于特征分解模式的软件产品线参考设计方法

基于特征的领域分析与建模技术是软件产品线开发中较为主流的需求建模方法,为描述产品线共性和可变性及其之间的关系提供了良好的支持。然而在现有特征模型基础上,如何指导系统开发人员进行软件系统的详细设计是亟待解决的问题。该问题主要体现在特征之间的结构与语义关系,以及特征的可变性如何映射为合理的系统设计模型这两个方面。针对上述问题,提出一种基于特征分解模式的软件产品线参考设计方法。该方法为特征模型中具有不同结构、不同语义的特征分解模式提供参考的详细设计方案,并提出相关聚类准则以支持对应全局特征模型的设计模型优化。最后,通过成绩录入软件产品线对该方法的有效性进行验证。     

以OOEDB为核心的集成化CAD/CAPP/CAM 系统GS-ICCC的设计与实现

ＧＳ－ＩＣＣＣ是一个以自行研制开发的面向对象工程数据库管理系统ＯＳＣＡＲ为核心的集成化ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统，它的主要特点是按照ＳＴＥＰ标准在全局产品数据模型基础上实现ＣＡＤ，ＣＡＰＰ，ＣＡＭ的信息集成，本文围绕着这一原则介绍了ＧＳ－ＩＣＣＣ的系统总体结构，ＯＳＣＡＲ功能组织，全局产品数据建模框架以系统集成的设计与实现。     

Integrating part and assembly modelling

Current modelling systems adequately support either modelling of parts or modelling of assemblies, whereas ideal modelling systems should adequately support both. To achieve this, a new modelling system has been developed, which uses enhanced multiple-view feature modelling. This advanced modelling approach provides specialised interpretations of a product for different development phases, by means of so-called feature views, and ways to keep these interpretations consistent, i.e. to make sure that they all represent the same product. The paper concentrates on the views that support detail design of parts and assembly design of the whole product, and the way these views are related and kept consistent. It describes the features and the tools that can be used to build and maintain the feature models of the views. An example modelling session is given to illustrate the benefits of such integrated modelling.     

Numeric and curve parameters for freeform surface feature models

The success of feature modelling systems depends to a large extent on offering user-friendly ways for specifying and varying feature models. In this paper, several new facilities are introduced for this.Numeric and curve parameters are presented for specification and variation of freeform surface feature models. Several properties of the parameters can be defined, such as the direction of evaluation for a curve parameter. In addition to parameters present in features, other parameters can be added to a feature model, including intersection curves between features.To provide these facilities, a new three-level structure is introduced, which includes a partially evaluated model that can capture new generic model entities, including feature intersection curves. The work has been implemented in a prototype surface feature modelling system with functionality for feature class definition, feature model creation, and advanced feature model variation through the new types of parameters.     

Multiple-view feature modelling for integral product development

To allow a designer to focus on the information that is relevant for a particular product development phase, is an important aspect of integral product development. Unlike current modelling systems, multiple-view feature modelling can adequately support this, by providing an own view on a product for each phase. Each view contains a feature model of the product specific for the corresponding phase. An approach to multiple-view feature modelling is presented that supports conceptual design, assembly design, part detail design and part manufacturing planning. It does not only provide views with form features to model single parts, as previous approaches to multiple-view feature modelling did, but also a view with conceptual features, to model the product configuration with functional components and interfaces between these components, and a view with assembly features, to model the connections between components. The general concept of this multiple-view feature modelling approach, the functionality of the four views, and the way the views are kept consistent, are described.     

面向集成的特征基产品建模系统研究

本文归纳总结了面向集成的产品建模CAD系统的当前特征及其发展趋势，指出了其发展的主要研究内容，并由此提出了面向集成的产品建模系统新的体系结构，重点论述了基于约束的特征基产品描述方法。     

Solid modelling in a virtual reality environment

This paper presents a constraint-based methodology for intuitive and precise solid modelling in a virtual reality (VR) environment. A hierarchically structured and constraint-based data model is developed to support solid modelling in the VR environment. A constraint reasoning engine is also developed to automatically deduce allowable motions for precise constraint-based 3D manipulations. A prototype system of product modelling has been successfully developed, and experimental results demonstrate the advantage of precise solid modelling through constraint-based manipulation in virtual environments.