Development of a metal selector system

There are an increasing number of different material types currently available for a number of industrial applications. A designer must not only have the ability to decide upon a suitable material for a specific product but also be able to optimise that choice. It is expected that an information source such as the proposed database will provide all the necessary facts and figures to aid both designers and manufacturing engineers. In this paper, a metal selecting system is designed and developed for use in design and manufacturing applications. Incorporated into the system are two main features, browse and search. These allow the user to sift through information manually or enter multi-constraint criteria respectively. Retrieval of information is achieved by in-built queries and information is displayed in two media, forms and reports, with printouts available. All features can be used as part of a sequential screening process, guiding the user to an eventual metal shortlist or selection.     

A component-based product data management system

Companies today have been attempting to expand their Internet infrastructures to cope with the growth of global business environments. In modern manufacturing industries, they are migrating their legacy product data management (PDM) systems to Web-based systems (being an essential tool of eManufacturing) to use the Internet. Accordingly, recent advances in PDM technology have dealt with the use of Web-based technology. Some research and development on Web-based PDM systems has been described in the literature, but those efforts have technical limits. They are not adequately available, secure, reliable, and scalable for global enterprise services. This paper describes the design of a component-based product data management (CPDM) system for supporting global manufacturing. The CPDM system is aimed at assuring flexibility, security, stability, and maintainability by utilizing a standard architecture of J2EE technology. The CPDM system consists of three tiers based on the J2EE architecture. The first is the presentation tier implemented as JSP/servlet components to allow users to access the system through a Web browser. The second is the business logic tier, which is implemented as Enterprise JavaBeans (EJB) components to handle the core PDM functionality. The third level is the data tier, composed of a database and vault for the physical files. To develop the components of the CPDM system, a component-based development (CBD) approach is proposed. The associated component development procedure is illustrated with examples. The CPDM system is also tested for its performance.     

Extraction of manufacturing information from design-by-feature solid model through feature recognition

Feature recognition is the key to the computer-aided design (CAD) and computer-aided manufacturing (CAM) integration to build a computer-integrated manufacturing system. There are two approaches to CAD feature recognition: platform-dependent and platform-independent. In the platform-independent approach, the part’s geometrical data are extracted from a neutral file such as DXF, IGES, or STEP. In contrast, the platform-dependent approach extracts the information of the design features directly from a design-by-feature solid model through the object-oriented model of a part. This paper explains a platform-dependent approach which is implemented to translate design features into manufacturing information. This approach begins with simplification using the suppression of fillets, and clustering non-intersecting design features is done. Then, the rule-based method is employed in order to recognize machining features. Finally, the needed manufacturing information such as tool accessing direction, dimensions, material removal regions, and geometrical and topological data is recognized. The application of the proposed system would be exhibited in generating machine path code for rapid prototyping and CNC machines and providing a database for computer-aided process planning. The proposed system was implemented on Autodesk Inventor and successfully tested for many complex 3D models.     

An Information Modelling Framework to Support Intelligent Concurrent Design and Manufacturing of Sheet Metal Parts

Sharing of information is an important issue in supporting integrated and rapid product development. The use of information modelling technology is a promising approach for solving the problems of the intensive sharing of information in a concurrent and rapid product development cycle. This paper explores the definition and the structure of a framework of information modelling for the concurrent design and manufacturing of sheet metal parts. This framework aims to build an information bridge to fill the gap between the sheet metal part design and manufacturing systems. It is based on abstract handling principles of entities called zero thickness and zero bend radius principles. Based on this framework, information models can be built for information sharing by different systems. Knowledge bases that support intelligent concurrent design and manufacturing can also be created. In this paper, a two-branch tree based stepping-structure information modelling methodology for sheet metal parts is described, and a case study is given.     

基于Pro/E二次开发夹具标准件参数化设计技术研究

目前夹具设计、制造手段的落后已经成为制约产品质量和生产率提高的“瓶颈”，本文针对机床夹具设计时标准件的重复建模，提出基于Pro／E二次开发的夹具标准件三维模型自动生成的办法。通过输入标准件的相关参数即可获得自动生成的标准件，然后通过图形的Web显示技术，实现网页图形的浏览，从而提高效率。     

行业产品的Internet信息搜索研究

专门的行业领域信息搜索问题和通用的搜索引擎有较大的区别，本文首先设计了一个面向行业产品的信息搜索系统的实现框架，探讨了行业信息的特征表示，特征匹配的实现这个前台信息数据的主动获取过程，同时也讨论了集中式行业信息数据的信息检索这一后台信息检索问题，通过该系统，可以方便行业内的企业用户和技术人员快速，高效地获取比较精确和技术性强的信息。     

电动机端盖的参数化设计

电动机端盖是一种系列化的产品．对于同一类型的产品其结构模型基本上是不变的．所不同的只是产品结构尺寸的不同．因此可利用Pro／E的单一数据库的特点实现参数化设计．同时利用VB的可视化特点，对Pro／E的用户界面进行封装，运用交互方式输入零件信息，自动生成电动机端盖零件。     

Mechanical Product Disassembly Sequence and Path Planning Based on Knowledge and Geometric Reasoning

A feature-based assembly model is proposed for disassembly sequence planning, and establishing a correct and practical disassembly path for the part in the product, based on geometric reasoning and knowledge. The fundamental assembly modelling strategy for a product is based on the mating features of its parts. An algorithm is introduced which uses the information provided by the mating features of parts in the product to find the candidate parts for disassembly and to carry out disassembly path planning. A complete and accurate interference checking approach is used to ensure no global collision while disassembling a part. In some cases, it cannot be implemented by geometric reasoning alone, so a set of criteria and heuristic rules based on knowledge, constraints, relationships among parts, and quantitative disassemblability assessment are used. It can also be carried out interactively by the user when necessary. The proposed method is integrated with the CAD model of the product. The user can visually disassemble the product while planning, so it is easier to carry out the disassembly planning and generate an optimal sequence.     

满足装配建模的标准件库的设计与实现

在装配建模过程中,三维标准零件是构成产品模型整体的一个不可缺少的部分。 本文深入分析了面向装配的标准件库的信息结构,提出和实现了满足装配建模的一 种标准件建库方法和建库工具。系统具有友好的用户界面和方便的标准件装配操作。     

Approach to the production environment design task within factory coordination

In a discrete parts batch manufacturing environment, there are different data flows concerning the design of products and manufacturing facilities, customer orders, purchase of materials, production control and delivery of orders. Traditionally, because of the functional allocation of tasks within an organization, there is little integration of information between the production control task and the design of manufacturing facilities. One of the objectives of the design of manufacturing facilities tasks is to efficiently organize a production environment to manufacture a range of products. With a greater relationship between these two tasks, we feel that the complexity of the production control task is reduced. This reduction in complexity arises from a reduction in the range of possible problems that can occur and an increase in the predictability of events through more effective organization of a production environment. Factory coordination is part of an approach to shopfloor control which recognizes this principle by establishing a relationship between the design of a production environment and the control of product flow throughout a factory. This relationship is established through a modular architecture for factory coordination. The production environment design element of the architecture for factory coordination is concentrated on. Using a methodology for describing systems, known as SADT, three main tasks associated with this approach are described; process planning, maintenance of a cellular layout, and manufacturing systems analysis.     

基于WWW/Internet个性化制造系统的构造方法研究

在分析异地设计、协同设计系统的基础上,提出了一种基于WWW/Internet个性化制造系统结构。个性化制造系统就是在Internet环境下,能够使个体用户参与企业的产品设计与制造过程,从而实现产品的个性化,提高产品创新能力。讨论了在个性化制造系统实现中的几个技术问题——产品信息模型、以产品类为导向的产品设计方法组件,以及基于Web的产品驱动模式。     

Computer aided manufacturing planning for mass customization: part 3, information modeling

To facilitate the computer-aided manufacturing planning (CAMP) for mass customization, an information model is developed for integrating the information exchange in different levels of CAMP activities. The correlative relationships between product design and manufacturing processes are established by using an object-oriented system analysis model so that the manufacturing system design can be adaptive to the change of the product design. The information model is implemented in a prototype CAMP system for part family.     

法兰盘类零件检索式CAPP系统在数控加工中的设计与实现

针对数控加工中零件信息的多样性,整合CAPP和NC中的共用资源,设计法兰盘类零件的检索式CAPP系统。检索式CAPP系统建立在成组技术基础上,利用零件的工艺相似性,通过检索和修改标准工艺(典型工艺)规程来制定相应的工艺规程[2]。在设计中涉及到成组技术、特征编码以及数据库设计与开发等关键技术。在实例开发中,以成组技术为理论指导,用Access创建零件工艺数据库,VB开发相应程序。该系统可直接检索已有的零件,可对任意法兰盘类零件进行特征编码,并判断其族类,对已有的族类检索出相似工艺,修改后保存,可为数控加工编程做准备。     

超大扭矩高精度分度回转装置设计理论与CAD程序开发

超大扭矩高精度分度回转装置是大型转子加工中的关键部件,常用在大型数控机床实现零件的精确分度。为提高分度回转装置分度精度和设计效率,需要找出影响分度装置精度的关键因素,探究超大扭矩高精度分度回转装置设计方法,在此基础上,采用Matlab开发分度装置计算机辅助设计(CAD)程序,该程序利用Matlab软件的GUI进行程序界面设计,可预先将不同规格的零部件参数通过用户界面写入数据库,当负载变更时,可以随时调用数据库的参数,快速查询可替换零部件,实现高可靠性高精度分度回转装置的快速设计。     

A Distributive and Collaborative Concurrent Product Design System through the WWW/Internet

Concurrent engineering involves the integration of people, tools, information, and processes into a responsive and efficient system. This paper addresses a key requirement in distributed concurrent engineering, namely, the ability for geographically dispersed and disparate parties, having heterogeneous computing platforms, to exchange design and manufacturing data. The development of an effective and efficient collaborative product design support environment based on the WWW/Internet is presented. A new method that reduces the transmission time through the use of macro files is proposed to realise the real-time communication, together with a monitoring methodology for synchronising group operations, and maintaining consistency of shared CAD models in a cooperative design review (co-modifying) process. Based on the proposed methods, a software interface has been developed to extend the traditional single location CAD software system to a multi-location application for coordinated product design through the Internet. This software interface was coded in Java. The architecture is a connection-oriented client/server structure using TCP/IP protocol. Unigraphics on a UNIX Workstation and MicroStation on Windows NT have been successfully integrated. The findings of this paper allow product designers to exchange and share product data, communicate with team members, modify geometry data on particular aspects of the design, and maintain operations consistency in all the distributed cooperative sites on a wide variety of platforms.     

动态扩充的零件库系统的研究与开发

在对零件库设计方法进行了深入研究和分析的基础上 ,提出了基于 C/ S模式的零件库系统构架 ,设计了链表式数据库 ,并提出了基于链表式数据库的动态匹配算法 ,实现了零件库 (含组合件 )系统的动态扩充和零件及组合件尺寸参数的离线编辑功能 ,从而大大地提高了零件库、组合件库的建库效率 ,所开发的零件库系统已应用于“基于知识的机床夹具 CAD系统”,取得了良好的效果     

基于STEP的制造资源能力建模及其应用研究

分析了并行工程对制造资源的需求特点,基于ＳＴＥＰ建立了制造资源能力模型,采用面向对象技术,建立了制造资源库和制造知识库;基于制造资源和制造知识,进行零件可制造性评价与反馈,从而指导产品设计。     

Manufacturing e-quality through integrated web-enabled computer vision and robotics

This paper investigates the development of a Web-based quality control system with the use of Internet-based computer machine vision. Such a system allows designers located far from the production facility to monitor, control, and program the quality inspection process as the product design evolves. Quality control tasks are performed and monitored remotely through the Web where Internet-based machine vision sensors inspect part dimensions and tolerance while Internet-enabled robots perform the necessary robotic operations. The remote quality monitoring system—which lets the user monitor the part status including data, image, and video through the Internet—is built using Java. The use of Java allows for interconnection and data transfer between the different components of the Web-based quality system and the robots. The ability to access and control quality control devices via the Web benefits the current manufacturing environment in the following ways: ubiquitous access to the production floor, remote control/programming/monitoring capability, and integration of production equipment into information networks for improving efficiency and product quality.     

基于灰相似关系和多维关联约束的新产品初始配置方法

为了解决新产品开发策划中将目标新产品概念模型中的结构化功能技术特性快速转化成新产品初始结构配置的问题,建立了多维关联约束的零部件资源库模型,针对分解后的新产品功能技术特性要求,根据零部件灰相似关系从零部件库查找出对应匹配或近似匹配的候选实例,按照零部件对产品总体功能技术作用的重要度排序,通过多维关联约束驱动和迭代匹配,逐步形成各零部件的总体候选方案,并根据综合匹配度确定最终匹配方案及其待改型设计和新设计的零部件。最后,通过一个实例对所提出的方法进行了验证。     

A concurrent manufacturing strategy for One-of-a-Kind Products with complicated sculptured surfaces

In this paper, we propose a computer-aided system for concurrently designing and manufacturing a customised or One-of-Kind Production (OKP) mould or die which has complicated sculptured surfaces. Considering the OKP production characteristics of high customisation and concurrent product development and production, we believe that the concurrent consideration of both the design and the manufacturability of a mould or a die would be necessary. This concurrence can be realised by providing timely manufacturability information feedback after a design is completed or a feature is modified or added in the design. The other problem is that the sculptured surface geometry model of a mould or a die does not contain any machining information. Hence we developed an intermediate data model for capturing manufacturing features when we are modelling the geometric form of a mould or a die. The system is based on CADDS5 which is a commercial CAD/CAM system. Two modules for data extraction, coverting and modelling as well as for manufacturability analysis have been developed and added to CADDS5. Using this computer-aided system; a designer can interrogate geometry and machining constraint information through a user friendly interface to avoid defects and inefficiency resulting from an earlier design, and can finalise the design by making quick incremental adjustments. The system has been implemented in a mould and die manufacturing company in China. This implementation leads to less rework and shorter lead time.