一种面向方案设计的装配建模表示方法

ＣＡＤ系统对方案设计支持的关键是建立独立于几何细节而又表达的功构关系的装配模型,本文试图运用逻辑装配单元的定义来实现产品功能需求和结构表现间的有效关联,分别讨论了方案设计中功能描述和几何构形表示方式,形式化表达了方案设计的逻辑造型和装配建模过程,给出了支持自顶向下方案设计的装配模板定义,为方案设计的计算机辅助实现作了有益的尝试。     

基于定性立体模型的产品可装配/拆卸性分析

探讨如何在尚未确定完整的定量信息的概念设计阶段实现计算机辅助设计产品可装配／拆卸性分析的问题，首先分析了概念设计的产品信息特点，提出定性装配模型的概念，该模型描述了零件间的壮配关系和零件的定性形状，然后提出一种可装配／拆卸性分析方法，该方法以定性的位置和形状为基本信息，通过分析零件的可移动性和移动方向，进行零件的装配／拆卸性分析。     

A geometric modelling framework for conceptual structural design from early digital architectural models

Computer support for conceptual structural design is still ineffective. This is due, in part, to the fact that current computer applications do not recognize that structural design and architectural design are highly interdependent processes, particularly at the early stages. The goal of this research is to assist structural engineers at the conceptual stage with early digital architectural models. This paper presents a geometric modeling framework for facilitating the engineers’ interactions with architectural models in order to detect potential structural problems, uncover opportunities, respect constraints, and ultimately synthesize structural solutions interactively with architectural models. It consists of a process model, a representation model and synthesis algorithms to assist the engineer on demand at different stages of the design process. The process model follows a top-down approach for design refinements. The representation model describes the structural system as a hierarchy of entities with architectural counterparts. The algorithms rely on geometric and topologic relationships between entities in the architectural model and a partial structural model to help advance the synthesis process. A prototype system called StAr (Structure-Architecture) implements this framework. A case study illustrates how the framework can be used to support the conceptual structural design process.     

面向网络化协同模板技术的模板设计标记语言

提出了基于XML、面向协同设计的模板设计标记语言———TDML,提炼了TDML的定义及特征,阐述了TDML的语法及语义,并介绍了协同模板可视化设计环境及其包含的有关TDML实现与设计的运行框架;针对该框架下的模板解释器及模板分割与复合、模板结构和参数分离与合并等操作模块进行了描述,给出了模板与可视化造型库的接口.最后以冷冲模与沙发为实例,验证了TDML在协同模板可视化设计系统中的有效性.     

符号方案三维实体化的自动化方法研究

如何将创新设计过程中得到的符号方案生成直观的图形方案，是机械概念设计中的关键技术问题，通过对符号方案的邻接矩阵元素进行分析，得到机构的结构组成、构件连接关系等信息；运用符号方案的尺度矩阵确定各装配构件的二维几何尺度，在面向对象二次开发的环境下，基于三维参数化平台，实现构件的三维实体化；根据构件所处空间位置，按后台预置装配方法得到三维虚拟实体装配图。上述过程基于面向对象的环境，输入／读入概念设计得到符号方案后，系统自动地将符号方案生成三维虚拟实体方案。     

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.     

A smart conflict resolution model using multi-layer knowledge graph for conceptual design

Reducing the impact of conflicts on requirement-function-structure mapping in the early stage of product design is an important measure to achieve conceptual innovation, which relies on accurate reasoning of multi-domain knowledge. As product requirements become more personalized and diverse, traditional discrete knowledge organization and reasoning methods are difficult to adapt to the challenges of continuity and precision in conceptual solution. Knowledge graphs with complex networks have obvious advantages in association detection, knowledge visualization, and explainable reasoning of implicit knowledge, which offer innovative opportunities for conflict resolution in conceptual design. Therefore, a smart conflict resolution model using a multi-layer Knowledge Graph for Conceptual Design(mKGCD) is proposed in this study. A knowledge expression form of FBS-oriented design patent vocabulary is proposed, which is used for knowledge entity recognition and relation extraction based on natural language processing. A label mapping method based on inventive principles is used for patent classification and a four-layer semantic network for conflict resolution is constructed. Through semantic distance calculation, the designer's requirements for function/behavior/structure are smart deployed to obtain appropriate knowledge. A case study of the conceptual design of a collapsible installation and handling equipment demonstrates the feasibility of the proposed approach. The proposed method can not only meet the functional solution and innovation in the context of different design requirements, but also effectively improve the design efficiency in the iterative design process by means of multiple meanings of one graph.     

Conceptual design, manufacturability evaluation and preliminary process planning using function-form relationships in stamped metal parts

A large number of design decisions are made during the conceptual design of a part. However, there are few representation and reasoning tools for decision support during conceptual design. The conceptual design stage is characterized by a lack of complete geometric information. Existing geometric modelers require complete geometric information, while a functional reasoning methodology using a <verb, noun > representation is typically too terse. In this paper, we present a new representation called sketching abstraction for conceptual design, using the function-form relations in a design. The functionally critical part of the geometry is presented using a set of functional features, while the rest of the geometry is abstracted as a set of linkages. Part functionality is correlated with the sketching abstraction using data structures called function-form matrices. The sketching abstraction is annotated using a set of primitives, and a set of grammar rules are used to extract canonical relationships between the functional features. The sketching abstraction can be used for extracting designs that are geometrically dissimilar but functionally similar, thus providing the designer with ideas for design alternatives. The sketching abstraction can also be used to carry out domain-dependent manufacturability evaluation checks. A further use of sketching abstractions is to initiate the development of a process plan for manufacturing. Sketching abstractions are related to the solid model of a part. Thus, this representation provides a link between pure functional and pure geometric representations. The domain of application is stamped metal parts. We present the part functionality and the features used in this domain. We also illustrate the use of sketching abstractions for conceptual design, manufacturability evaluation and preliminary process planning.     

Knowledge-based approach and system for assembly oriented design,Part I: the approach

Assembly is one of the most important stages for product development. Assembly-oriented design (AOD) is a new approach to designing assemblies, which uses a number of design and analysis tools to help the designer plan out and analyze candidate assembly schemes prior to having detailed knowledge of the geometry of the parts. Using this approach, many assembly schemes can be inexpensively evaluated for their ability to deliver the important characteristics of the final product. This research proposes a knowledge-based approach and develops an expert design system to support top-down design for assembled products. The presentation of research report is divided into two parts: the knowledge-based approach (Part I) and the knowledge-based expert design system (Part II). This paper is the first part of the report (Part I), which mainly proposes a knowledge-based approach and framework for intelligent assembly oriented design. The proposed approach focuses on the integration of product design, assemblability analysis and evaluation, and design for assembly with economical analysis. It differs from the existing approaches adopting the part-first bottom-up modeling technique, in which a hybrid model related to design problem-solving including function–behavior–structure model, feature-based geometric model, and parametric constraint model is used as a comprehensive intelligent framework for assembly modeling and design in a top-down manner from the conceptual level to the detailed level. Through the use of intelligent approach and framework, concurrent engineering knowledge can be effectively incorporated into the assembly design process, and a knowledge-based expert design system can be implemented.     

Knowledge-based approach and system for assembly-oriented design,Part II: the system implementation

Assembly is one of the most important stages for product development. Assembly-oriented design (AOD) is a new approach to designing assemblies, which uses a number of design and analysis tools to help the designer plan out and analyze candidate assembly schemes prior to having detailed knowledge of the geometry of the parts. Using this approach, many assembly schemes can be inexpensively evaluated for their ability to deliver the important characteristics of the final product. This research proposes a knowledge-based approach and develops an expert design system to support top-down design for assembled products. The presentation of research report is divided into two parts: the knowledge-based approach (Part I) and the knowledge-based expert design system (Part II). This paper is the second part of the report (Part II). It will focus on the development of knowledge-based expert design system for assembly oriented design. The knowledge-based assembly oriented design system, i.e., the assembly oriented design expert system (AODES) is constructed to integrate assembly modeling and design, assembly planning, assemblability analysis and evaluation within a concurrent engineering environment. This intelligent system is implemented by integrating object-oriented representation, constraint-based modeling, rule-based reasoning, truth maintenance, and interfacing to database management system and CAD module, in which fuzzy logic based knowledge representation and inference technique are also applied to deal with uncertain data and knowledge in the design process. The developed system differs from the existing systems adopting part-first bottom-up modeling technique, in which a comprehensive intelligent framework is used for assembly modeling and design in a top-down manner from the conceptual level to the detailed level. It is able to help obtain better design ideas, provide users with suggestions so as to create and improve a design, and therefore give users the possibility to assess and reduce the total production cost at an early stage during the design process. Through the use of the system, the concurrent engineering knowledge can be effectively incorporated into the assembly design process in an integrated manner. A case assembly design shows that the intelligent modeling and design system is feasible.     

Knowledge intensive Petri net framework for concurrent intelligent design of automatic assembly systems

The integration of design and planning of flexible assembly system has been recognized as a tool for achieving efficient assembly in a production environment that demands assembly with a high degree of flexibility. This paper proposes a concurrent intelligent approach and framework for the design of robotic flexible assembly systems. The principle of the proposed approach is based on the knowledge Petri net formalisms, incorporating Petri nets with more general problem-solving strategies in AI using knowledge-based system techniques. The complex assembly systems are modeled and analyzed by adopting a formal representation of the system dynamic behaviors through knowledge Petri net modeling from the specifications and the analysis of those models. A template is first defined for a knowledge Petri net model, and then the models for assembly system individuals are established in the form of instances of the template. The design of assembly systems is implemented through a knowledge Petri net-based function–behavior–structure model. The research results show that the proposed knowledge Petri net approach is applicable for design, simulation, analysis and evaluation, and even layout optimization of the flexible assembly system in an integrated intelligent environment. The integration of assembly design and planning process can help reduce the development time of assembly systems.     

用三维几何约束构建概念化设计阶段的三维布局

概念化设计是产品设计中的一个重要环节，其主要任务是实施产品结构的空间布局，并确定连接关系．由于概念化设计阶段产品结构信息不明确，因此现有的三维设计工具(如solidedge7．0，MDT等)无法有效支持概念化阶段的设计活动．在对装配关系进行抽象的基础上，利用三维约束与驱动实现概念化设计阶段的空间布局设计活动，为进行三维设计工具自顶向下的设计模式奠定了基础．     

An integrated temporal data model incorporating time series concept

Most temporal data models have concentrated on describing temporal data based on versioning of objects, tuples or attributes. The concept of time series, which is often needed in temporal applications, does not fit well within these models. The goal of this paper is to propose a generalized temporal database model that integrates the modeling of both version-based and time-series based temporal data into a single conceptual framework. The concept of calendar is also integrated into our proposed model. We also discuss how a conceptual Extended-ER design in our model can be mapped to an object-oriented or relational database implementation.     

A framework for collaborative top-down assembly design

This paper presents a new system framework for collaborative top-down assembly design. Different from current computer-aided design (CAD) systems, the framework allows a group of designers to collaboratively conduct product design in a top-down manner. In our framework, a multi-level and distributed assembly model is adopted to effectively support collaborative top-down assembly design. Meanwhile, fine-granularity collaborative design functionalities are provided. First, the coupled structural parameters involved in the distributed skeleton models of the product can be collaboratively determined by the correlative designers based on fuzzy and utility theory. Second, agent based design variation propagation is achieved to ensure the consistency of the multi-level and distributed assembly model during the whole design process. Third, collaborative design of assembly interfaces between the components assigned to different designers is supported. The prototype implementation shows that our framework works well for supporting practical collaborative top-down assembly design.     

产品的相似性推理:一种描述逻辑的方法

采用产品本体理论对设计进行本体标注，得到对应产品设计的形式化概念，在此基础上通过本体的推理——基于描述逻辑的知识推理，对产品进行分类．文中分别就设计的相似性和基于实例的设计中实例间的相似性推理提出了明确的算法，并通过实例进行了说明．     

INTELLIGENT CAD SYSTEM IN CONCURRENT ENGINEERING ENVIRONMENT: A KNOWLEDGE-BASED APPROACH

The objective of this paper is to investigate specific methodologies for conceptual design and to establish a computational framework for an intelligent CAD system in a concurrent engineering environment. The main idea in developing such a system is to help designers in conceiving better design ideas within given sets of design, manufacturing, and assembly constraints. It is, therefore, essential to integrate intelligently diverse knowledge sources from different fields of manufacturing (e.g., design, process planning, assembly, inspection). When an object creation process is complete, the system analyzes the structure in consultation with its intelligent computational modules (“local experts”) to make sure that no functional, geometric design or manufacturing constraints are invalidated and to suggest an alternative better design, whenever possible. The paper also discusses the implementation of a prototype system for automated fixture design in the proposed concurrent engineering environment.     

Multiobjective layout optimization of robotic cellular manufacturing systems

This paper proposes a multiobjective layout optimization method for the conceptual design of robot cellular manufacturing systems. Robot cellular manufacturing systems utilize one or more flexible robots which can carry out a large number of operations, and can conduct flexible assemble processes. The layout design stage of such manufacturing systems is especially important since fundamental performances of the manufacturing system under consideration are determined at this stage. In this paper, the design criteria for robot cellular manufacturing system layout designs are clarified, and objective functions are formulated. Next, layout design candidates are represented using a sequence-pair scheme to avoid interference between assembly system components, and the use of dummy components is proposed to represent layout areas where components are sparse. A multiobjective genetic algorithm is then used to obtain Pareto optimal solutions for the layout optimization problems. Finally, several numerical examples are provided to illustrate the effectiveness and usefulness of the proposed method.     

基于虚拟化技术的卫星控制系统软件构件库运行监控与可信验证技术

动态系统建模工具可以按照设定的仿真步长对控制器的行为动态模拟,也可以在仿真环境下模拟控制器所在的系统架构和动态数据交互,因此传统的卫星控制系统方案设计时一般采用在同一模型建模体系进行,并进行相应的控制算法设计。但是由于动态系统建模工具其自身的时钟步长和数据流处理逻辑,不能完全模拟目标机的内部ALU逻辑和真实外围设备工作行为,可能与真实物理环境要求的系统有一定的出入,造成对承载卫星控制器功能的目标机CPU处理系统存在一定程度的失真,影响仿真效果。提出了一种基于虚拟化技术的卫星控制系统软件构件库可信验证技术,使用虚拟化技术实现对真实物理目标机功能的完全模拟,运用软件非干涉运行监控技术,获取可信的开发证据和应用证据,利用协同仿真组件和卫星控制系统方案设计的控制算法模型对各个软件构件进行动态同步仿真验证。