A PDES/STEP-based model and system for concurrent integrated design and assembly planning

Product data exchange and interfacing between different CAD/CAM systems are of great importance to the development of concurrent integrated design environments and computer integrated manufacturing systems. This paper presents a STEP-based method and system for concurrent integrated design and assembly planning. An integrated object model for mechanical systems and assemblies is first defined by a hierarchy of structure, geometry and feature. The structure is represented as a component-connector or joint multi-level graph with both hierarchical functional and assembly relations. These hierarchical relation models are then used for uniformly describing their causal relations both for assembly level and feature based single part level. The generic product assembly model is organized according to STEP, using mostly the entities of integrated resources and partly self-defined entities, which are necessary for design and assembly planning. Based on the generic product assembly model, STEP-based strategies and agent concepts are used for agent-based concurrent integration of design and assembly planning. A prototype system, consisting of a CAD system, a product modeling system, an assembly planning system, and an assembly evaluation system is developed, in which product data can be exchanged between these subsystems. Details about the implementation of the system are addressed. The integrated design and assembly planning system can support the introduction of a new product. The results of assembly planning are feedback to the stage of assembly design to improve on the design. A case study is carried out for assembly-oriented design of a gearbox, to illustrate the proposed approach and to validate the developed system.     

A user requirement driven framework for collaborative design knowledge management

In today’s competitive global marketplace and knowledge-based economy, user requirement becomes an important input information for enterprises to develop new product and a critical factor to drive product collaborative design evolution. Meanwhile, there remains no consensus on how best to support knowledge activities and significant challenges to establishing design information management facing to rapid collaborative product development with dynamic user requirement. This paper introduces solutions for designer to deal with dynamic user requirement information through requirement evaluation and prediction method. In this study, we propose a user requirements-oriented knowledge management concept that is based on a four level hierarchy map model with special regard to knowledge collaboration and information communication. Furthermore, a novel distributed concurrent and interactive user requirement database was constructed, and the framework driven by user requirement was put forward to support collaborative design knowledge management. Finally, the service robot design project of a start-up company is used as a case study to explain the implementation of proposed framework.     

面向并行设计的智能决策支持系统研究

基于并行设计支撑环境讨论了智能决策支持系统的重要性，论述了基于知识的并行设计过程和基于小循环的并行设计过程模型，建立了复杂产品并行智能决策支持框架，阐明了适合并行设计智能决策支持系统的领域知识描述模型，并以方案设计智能决策支持系统为例进行了验证。     

基于知识的机械产品并行设计

探讨面向对象的知识表达与推理方法以及知识的集成化组织结构。提出并行设计中多知识源相互合作交流和通过动态信息交换进行协同求解的策略。开发了以知识库系统为核心,以集成化产品信息模型为基础的机械产品并行设计系统。     

A CAE-integrated distributed collaborative design system for finite element analysis of complex product based on SOOA

Large-scale finite element analysis of complex product needs a wider support from external CAE resources. This paper proposes a method of the distributed concurrent and collaborative design in the distributed intelligent resources environment to use Web-based extended manufacturing resources for product development. The CAE-integrated distributed collaborative design system architecture and enabling techniques are presented. Distributed CAE service resources on the Internet are achieved through Jini^TM and service object-oriented architecture technologies. These CAE software tool resources are encapsulated as service providers in the system. A case study of railway bogie development is presented, and the Pro/E, HyperMesh, Ansys and HumanExpert service providers dynamically invoked and integrated as a temporary service federated environment with no need to know the exact location of a provider beforehand, flexibility can be well achieved, and collaborative design in the system can be implemented in the distributed dynamic environment. Compared with the traditional design system, some preliminary results indicate this architecture can shorten the cycle of service exchange, and strongly support concurrent and collaborative design of the complex product.     

ICADS: Intelligent Car Audio Design System for product planning

This paper describes the development of a system, ICADS (Intelligent Car Audio Design System), that can be used to effectively support product development engineers in car audio product design. We have demonstrated the use of expert system technology and the technique of quality function deployment (QFD) in supporting car audio design planning. QFD is applied as a knowledge acquisition method in this study to support car audio design teams in the development of products in a structured way that relates market demand via engineering specifications to parts specifications. We believe that other industries can use a similar approach for developing an expert system that can support product design planning.     

A decision support system for product design in concurrent engineering

Compared with the traditional sequential design method, concurrent engineering is a systematic approach to integrate concurrent design of products and their related processes. One of the key factors to successfully implement concurrent engineering is information technology. In order to design a product and its manufacturing process simultaneously, information on product features, manufacturing requirements, and customer demands must be processed while the design is concurrently going on. There is an increased understanding of the importance of the correct decisions being made at the conceptual design and development stages that involve many complex evaluation and decision-making tasks. In order to promote the efficiency in concurrent product development, appropriate evaluation and decision tools need to be provided. In this paper, the characteristics of fuzzy, multi-stage evaluation and decision making in concurrent product development process are analyzed and a decision support system for product design in concurrent engineering is presented. An example is given to illustrate the application of the system.     

A knowledge-based master model approach exemplified with jet engine structural design

Successful product development requires the consideration of multiple engineering disciplines and the quantification of tradeoffs among conflicting objectives from the very early design phases. The single-largest challenge to do so is the lack of detailed design information. A possible remedy of this issue is knowledge-based engineering. This paper presents a knowledge-based master model approach that enables the management of concurrent design and analysis models within different engineering disciplines in relation to the same governing product definition. The approach is exemplified on an early phase structural design of a turbo-fan jet engine. The model allows geometric-, structural mechanics- and rotor-dynamic- models to be concurrently integrated into a multi-disciplinary design and optimization loop.     

面向并行设计的虚拟原型技术研究

虚拟原型技术是在虚拟的逼真环境下,对产品设计信息进行协同仿真验证的有效手段,它可有效支持并行设计,缩短产品开发周期,在分析了虚拟原型与并行的关系后,提出了基于域对象的虚拟原型建模与仿真方法,并阐述了支持虚拟原型的集成框架的关键技术。     

Cost-effective design for injection molding

It is commonly agreed that a large proportion of the ultimate product cost is determined at product design stage. Therefore, a cost-effective design cannot be obtained unless all cost issues are resolved at early design stage. Therefore, instead of performing cost estimation after design, research presented in this paper aims to provide on-line cost evaluation and advisory to help product designers avoid cost-ineffective design. The objective can be obtained by (1) identifying factors that might affect product cost at each product design stage, (2) developing a design for cost effectiveness methodology that accommodates the concepts of concurrent engineering, and (3) developing a computer-based design for cost effectiveness system based on the proposed methodology. In this research, we focus on injection molding product design due to the advantages of injection molding process, such as high production rates, excellent quality and accuracy of the parts, and very long mold life. This paper first reviews and characterizes the conventional molding product development process with an emphasis on the identification of cost factors. Based on the results of process characterization, a cost model is developed, which depicts the relationships between cost factors and product development activities, as well as their relationships with product geometry. According to the product life cycle activities and the cost model, a design for cost effectiveness process is proposed. The process and the cost model are then employed for the development of a computer-based product design for cost effectiveness as one of the module of an integrated design for injection molding environment.     

Developing a quantitative intelligent system for implementing concurrent engineering design

This research focuses on the development of a quantitative intelligent system for implementing concurrent engineering design. The paper first discusses the task of concurrent engineering design and the basic requirements for conducting integrated concurrent engineering design. The proposed quantitative intelligent system approach combines qualitative reasoning, based upon design and manufacturing knowledge, and quantitative evaluation and optimization, conducted using design information and manufacturing data generated in the knowledge-based reasoning. The method allows considerations on non-operating principle aspects of a product to be incorporated into the design phase, such as manufacturing, maintenance, service, recycle, etc., with an emphasis on production costs. The proposed method serves as a convenient software tool for gathering information required in the concurrent engineering design process and integrates tasks from different parts of the product development life cycle, particularly function design, manufacturability analysis and production cost estimation. A prototype software system is developed based upon this method using Smalltalk-80. In the prototype system, concurrent engineering design is carried out by: (1) describing and representing design requirements; (2) generating feasible design candidates and evaluating their design functions; (3) representing design geometry; (4) finding the associated production processes and predicting the production costs of each feasible design; and (5) identifying the costeffective design that satisfies given design requirements and requires minimum production costs.     

The use of semantic networks to support concurrent engineering in semiconductor product development

The design of semiconductor devices is an extremely complex and costly process. Numerous design and test iterations are typically necessary to finally complete a successful device. Competition in the industry has forced semiconductor manufacturers to reduce design cycle times and costs. One method now being used to accomplish these objectives is concurrent engineering. This paper will review how concurrent engineering is being integrated into semiconductor device development and how artificial intelligence-based models will support concurrent engineering implementation. Major changes are needed in design simulation, methods of knowledge sharing, and incorporating best practices. A semantic network is proposed that retains the knowledge of a product in a central repository as various engineers contribute to the product's development. The knowledge contained in this central repository can be referenced for applicability by engineers during product design, development, and production.     

复杂耦合系统设计过程动态规划

产品复杂性导致了大容量耦合任务集的存在,而新产品上市时间是企业的核心竞争力;从而对耦合任务集设计过程进行规划、使其设计周期在任务期限内是敏捷制造模式下企业提高市场竞争力的一个有效手段。由此,基于并行工程的思想,论文提出了基于任务期限的耦合任务集设计过程规划模型,并由此构造了一个两层动态规划实现模型,为有效地管理与协调复杂耦合系统设计过程提供了一种途径。最后进行了实例验证。     

基于实例的产品设计知识获取方法及实现

现代产品设计是面向市场、功能驱动以及基于新知识的设计，而知识获取是关键步骤。采用设计实例的形式对已有设计进行封装和组织，通过产品设计实例面向对象表达模型，将设计需求（包括性能需求、环境约束和成本约束）、设计任务、设计过程和设计方案封装在一个设计实例中，体现了功能驱动、面向市场的现代设计特征。在此基础上，利用Sybase公司的PowerDesigner8.0建模工具，进一步提出产品设计实例的获取模型，并对实例获取的关键技术进行了讨论。以滑动轴承设计为工程应用背景，选择应用于涡轮机的四油叶径向滑动轴承为设计实例，详细描述了集成于SolidWorks2000的滑动轴承设计实例获取模块的应用过程，验证了上述模型的正确性和可行性。通过对设计实例进行表达、获取和存储，为后续的基于实例推理的产品设计方法打下基础，同时以对外提供功能的形式对并行设计环境下的功能检索提供支持，推动现代产品概念设计自动化进程。     

Development of a computer-aided concurrent net shape product and process development environment

This paper presents a systematic approach to developing a collaborative environment for computer-aided concurrent net shape product and process development. This approach includes the steps of (1) conventional development process analysis, (2) development process re-engineering, (3) computer-based system functional requirements analysis, (4) system framework design, and (5) system modeling, integration and implementation. This environment can support concurrent net shape product and process development by providing and integrating functions of product data management, process management and development advisory tools. The results of this research will facilitate the rationalization and automation of net shape product and process development and thus improve the efficiency and quality, and reduce the cost of net shape product development.

IDEF structural analysis methodology was employed to capture the characteristics of net shape product and process development process. The concept of concurrent engineering was used to re-engineer the development process. The technology of system engineering was used to design the computer-aided system framework. Object-oriented analysis, modeling and design methodology, knowledge engineering and data engineering techniques were employed for system modeling and implementation.     

基于实例模板的产品杂交配置设计

产品杂交配置设计是产品智能与创新设计方法的研究热点。基于产品模板配置设计概念,结合产品杂交配置设计需求,定义了面向杂交配置设计的知识库模型,提出了基于实例模板的机械产品杂交配置总体框架,给出了需求驱动、知识制导的产品杂交配置设计算法。该方法提供了统一的模型和框架,可有效支持各类机械产品杂交配置设计系统的研究和开发。     

Towards computer-aided configuration design for the life cycle

In modern design, life-cycle concerns such as recycling and service are receiving increased attention. The configuration design phase, where the product and component structure is established, is of particular importance when designing for the life cycle. In this paper, the foundation for a CAD system supporting configuration design for the life cycle is presented. A prototypical CAD system, called CODA (Configuration Design of Assemblies), is under development based on this foundation. A discussion on the supported product and component representation is given, followed by a portrayal of some of the capabilities to support life-cycle design. Specifically, requirements are identified for the information needed to support design for assembly, disassembly, service, recycling, and reuse. A case study involving the (re)design of a hand-held tape recorder with respect to improved disassemblability and recyclability is utilized to highlight some of the capabilities of the current system. With the new product and component representation embodied in CODA, improved support over current CAD systems is provided for configuration design and life-cycle design assessments.     

Product relationships management enabler for concurrent engineering and product lifecycle management

The current competitive industrial context requires more flexible, intelligent and compact product lifecycles, especially in the product development process where several lifecycle issues have to be considered, so as to deliver lifecycle oriented products. This paper describes the application of a novel product relationships management approach, in the context of product lifecycle management (PLM), enabling concurrent product design and assembly sequence planning. Previous work has provided a foundation through a theoretical framework, enhanced by the paradigm of product relational design and management. This statement therefore highlights the concurrent and proactive aspect of assembly oriented design vision. Central to this approach is the establishment and implementation of a complex and multiple viewpoints of product development addressing various stakeholders design and assembly planning points of view. By establishing such comprehensive relationships and identifying related relationships among several lifecycle phases, it is then possible to undertake the product design and assembly phases concurrently. Specifically, the proposed work and its application enable the management of product relationship information at the interface of product-process data management techniques. Based on the theory, models and techniques such as described in previous work, the implementation of a new hub application called PEGASUS is then described. Also based on web service technology, PEGASUS can be considered as a mediator application and/or an enabler for PLM that externalises product relationships and enables the control of information flow with internal regulation procedures. The feasibility of the approach is justified and the associated benefits are reported with a mechanical assembly as a case study.     

公理化设计与DFA集成的产品信息模型

在公理化设计理论的基础上，讨论了产品设计过程中功能要求的分解以及从功能域向结构域的曲折映射过程；建立了产品功能一结构层次模型和面向装配设计的产品信息模型．该产品信息模型不仅能够描述产品的层次结构信息，而且能够描述零部件之间的装配关系信息，能够实现CAD／CAE／CAPP/CAM的信息集成，为产品并行开发过程的信息集成打下良好的基础．以发动机减速器为例，对产品的功能树、结构树以及装配模型和装配关联矩阵的形成进行了说明。     

面向问题的多领域设计过程管理方法

现代产品设计的复杂性要求设计过程管理向高层转移,并能支持多领域并行设计,针对这种需求,文中提出基于问题解决模型的设计过程管理的概念与方法,将设计过程视为问题定义、规划与求解的过程,并利用过程描述语言捕获领域知识,通过设计过程文法,实现设计问题的求解与映射,该方法抓住设计过程的本质,可为设计者提供高层次跨领域的设计过程管理支持为设计周期的缩短提供了可能。