A virtual prototyping system for rapid product development

This paper describes a virtual prototyping (VP) system that integrates virtual reality with rapid prototyping (RP) to create virtual or digital prototypes to facilitate product development. The proposed VP system incorporates two new simulation methodologies, namely the dexel-based and the layer-based fabrication approaches, to simulate the powder-based and the laminated sheet-based RP processes, respectively. The dexel-based approach deposits arrays of solid strips to form a layer, while the layer-based approach directly forms a complete layer by extruding the slice contours. The layer is subsequently stacked up to fabricate a virtual prototype. The simulation approaches resemble the physical fabrication processes of most RP systems, and are therefore capable of accurately representing the geometrical characteristics of prototypes. In addition to numerical quantification of the simulation results, the system also provides stereoscopic visualisation of the product design and its prototype for detailed analyses. Indeed, the original product design may be superimposed on its virtual prototype, so that areas with dimensional errors beyond design limits may be clearly highlighted to facilitate point-to-point analysis of the surface texture and the dimensional accuracy of the prototype. Hence, the key control parameters of an RP process, such as part orientation, layer thickness and hatch space, may be effectively tuned up for optimal fabrication of physical prototypes in subsequent product development. Furthermore, the virtual prototypes can be transmitted via the Internet to customers to facilitate global manufacturing. As a result, both the lead-time and the product development costs can be significantly reduced.     

Combining Digital and Traditional Visualisation Techniques in Community-Based Planning and Design

Public participation is a key component in environmental planning and design. Yet too often, architects and planners are not equipped with effective tools and visualisation techniques to generate meaningful public input. Architects and planners are increasingly turning to computer technology; computer imaging can be used to support exploration of alternatives by enabling community members to visualise opportunities and scenarios before committing to a course of action (McClure, 1997). This paper explains how a Geographic Information System (GIS) and an artist played critical roles in a participatory planning process in Chicago's Pilsen neighbourhood. The GIS provided community leaders, planners, architects and designers with an interactive visualisation of the neighbourhood context. It also provided examples of design prototypes in relation to their geographic context. The artist, on the other hand, translated neighbourhood residents' ideas into quick sketches, merging their ideas and thoughts into a shared neighbourhood vision. Both of these elements – the GIS and the human artist – provided a means for residents to visualise past, present, and future neighbourhood conditions, enabling them to have a greater voice in the design of their neighbourhood. Our findings suggest that effective visualisation may be achieved through combining traditional and computerised visualisation tools, and that effective visualisation could assist in bridging the gap between professional designers and non-designers.     

A versatile virtual prototyping system for rapid product development

This paper presents a versatile virtual prototyping (VP) system for digital fabrication of multi-material prototypes to facilitate rapid product development. The VP system comprises a suite of software packages for multi-material layered manufacturing (MMLM) processes, including multi-toolpath planning, build-time estimation and accuracy analysis, integrated with semi-immersive desktop-based and full-immersive CAVE-based virtual reality (VR) technology. Such versatility makes the VP system adaptable to suit specific cost and functionality requirements of various applications.

The desktop-based VR system creates a semi-immersive environment for stereoscopic visualisation and quality analysis of a product design. It is relatively cost-effective and easy to operate, but its users may be distracted by environmental disturbances that could possibly diminish their efficiency of product design evaluation and improvement. To alleviate disturbance problems, the CAVE-based VR system provides an enclosed room-like environment that blocks out most disturbances, making it possible for a design team to fully concentrate and collaborate on their product design work.

The VP system enhances collaboration and communication of a design team working on product development. It provides simulation techniques to analyse and improve the design of a product and its fabrication processes. Through simulations, assessment and modification of a product design can be iterated without much worry about the manufacturing and material costs of prototypes. Hence, key factors such as product shape, manufacturability, and durability that affect the profitability of manufactured products are optimised quickly. Moreover, the resulting product design can be sent via the Internet to customers for comments or marketing purposes. The VP system therefore facilitates advanced product design and helps reduce development time and cost considerably.     

Automated merging of software prototypes

As software becomes more complex, more sophisticated development and maintenance methods are needed to ensure software quality. Computer-aided prototyping achieves this via quickly built and iteratively updated prototypes of the intended system. This process requires automated support for keeping track of many independent changes and for exploring different combinations of alternative changes and refinements. This article formalizes the update and change merging process, extends the idea to multiple changes to the same base prototype, and introduces a new method of slicing prototypes. Applications of this technology include automatic updating of different versions of existing software with changes made to the baseline version of the system, integrating changes made by different design teams during development, and checking consistency after integration of seemingly disjoint changes to the same software system.     

Comparison of intelligent CSCW architectures for the evaluation of agile manufacturing systems designs

Computer Supported Collaborative Work (CSCW) or Group Decision Support System (GDSS) can provide an efficient decision-making environment for multidisciplinary teams faced with the challenge of evaluating agile manufacturing systems. In this article, we describe the development and evaluation of CSCW prototypes to aid the systematic evaluation of agile manufacturing systems. An industrial case study involving the evaluation of alternative design configurations of a cellular manufacturing system for agile manufacturing was used for testing with 12 multidisciplinary student teams. The results obtained suggest that engineering design teams can obtain productivity improvements through the use of CSCW tools. In this study, we also found that an enhanced GDSS with a neural network module for preference aggregation outperformed a basic CSCW in: (1) decision quality, (2) users' satisfaction and agreement, and (3) consensus. © 1999 John Wiley & Sons, Inc.     

An e-contracting reference architecture

Business-to-business e-contracting aims at automating the contracting process between companies. It improves the efficiency of the contracting process and enables the introduction of new business models that can be supported by companies. For the development of an e-contracting system, an architecture is required that describes the system components and the communication channels between them. This paper presents a reference architecture for the development of e-contracting systems. The architecture is designed on the basis of a requirement analysis of e-contracting systems. Established architectural principles are used in its design. The architecture can serve as a foundation in the analysis and design of concrete architectures of e-contracting systems. Furthermore, it can be used as a standardization model that facilitates system integration and communication of ideas. Its value for both software architects and business professionals makes it an important tool in the analysis and implementation of e-contracting systems.     

Survey of collaborative drawing support tools

Along with recent experiments in the design of communication or computer tools for supporting various kinds of group working, the development ofcollaborative drawing systems has emerged as a notable research area within the field of Computer-Supported Cooperative Work. This paper reports a survey of the experiments in collaborative drawing support tools with an objective of reviewing how the issues of supportingcollaborative design have been addressed by the research prototypes. The survey is presented in three parts: (1) findings from the observations of group interaction in drawing and design activities, (2) a framework for classifying the design issues experimented with by prototypes developers, and (3) a categorisation of the current prototype systems by interrelating the patterns of group use observed with the system features classified. The survey indicates that there are currently at least three different strategies of developing collaborative drawing support tools, which reflect the existence of diversified understanding and technological responses to what and how human collaboration in design may be supported.     

网格模式下的高校教学平台研究与设计

在21世纪,网格即将成为第三代Internet。它是把整个因特网整合成一台巨大的超级计算机,实现资源的全面共享。而网络教学平台是以学生为中心,以网络和计算机为媒介,利用计算机模拟教学专家的思维过程,形成开放式的教与学交互系统。探讨了基于网格环境下网络教学平台的设计,充分发挥网络教学平台的作用,它的实现将对网络教育资源的全面共享和充分互用有着十分重要的意义。     

循环经济模式下的可持续设计

在全球环境日益恶化、资源日趋匮乏的背景下,可持续发展的思想受到了普遍的重视。可持续发展融入设计领域所形成的可持续设计也得到了普遍的关注。但是,可持续设计的理念和方法并没有快速地运用在设计项目中。可持续设计必须得到经济系统的强力支持才能得到有效的推广。循环经济就是适合可持续设计发展的经济模式。文章将从企业的角度出发,探索企业在循环经济模式下实施可持续设计的有效方式,从而推动企业设计战略的变革。     

Design evaluation and modification of mechanical systems in virtual environments

Design is one of the most important stages in the manufacturing cycle and influences all the subsequent stages of product development. In the context of today’s iterative design methodology, the modification of any design is a process involving many evaluations and improvements to the solutions chosen in earlier stages. For this purpose, in the most recent decade, 3D computer simulations have become common tools used within industry. Whilst virtual reality (VR) technology is seen as the interaction technology of the future, much of the current research in this area is carried out to explore the potential benefits and added value brought by the integration of this into standard software technologies currently used at various stages in manufacturing life cycle. A lot of attention has been given to exploring the usability and benefits of interactive VR for assembly planning, knowledge elicitation and design and simulation. However, little research has focussed on the analytical aspects of the design process, for example in the use of VR as an interface for simulation software in finite element methods and multi-body systems. This paper introduces research focussing on applications of virtual environments (VEs) for interactive design evaluation and modification adapted and used with standard simulation software. The use of such interactive visualisation offers the engineer more realistic real-time representations of the design and advanced facilities to interact with the model during the design process. While design evaluation is based mainly on visualisation; design modification requires interactive changes of the model during the simulation, and the interfaces described here highlights such applications. In this work, two software prototypes have been developed using VR technology. First, a software tool called design evaluation in virtual environments is presented together with an application in civil engineering to illustrate the mode of operation and added value of the use of an interactive visualisation environment. Linking the simulation software with the VE provides real time bi-directional communication of graphical information which can be successfully achieved even within the limits of current computer technology. The tool includes a suite of software modules and a user interface to facilitate the link between the simulation results and the VE. The second tool facilitates the design modification in virtual environments system by providing real time dynamic simulation. Two dynamic approaches are investigated in order to study the real time simulation issues in the context of design modification and system performance: the classic approach based on rigid interconnected bodies, and a new and novel approach developed by the authors based on particles dynamics. Both implementations have been tested and compared on a mechanism application under the same computing conditions. The research applications presented demonstrate the practicality, flexibility and versatility of the visualisation in virtual environment in design evaluation and modification. However, the computer efficiency whilst carrying out real time dynamic simulation is limiting the range of applications to models of moderate size; however, this is an improvement on previous similar applications.     

IPTES: A concurrent engineering approach for real-time software development

The constantly increasing concurrency, complexity, and risks associated with the industrial development of real-time embedded computer systems has been approached in different ways in recent years. In Esprit project no. EP5570, called IPTES, a methodology and a supporting environment to support the Boehm's spiral process are being developed. The prototyping environment will enable the specification, development, and verification of executable system models so that different parts of the system may represent different modeling levels and yet can be executed as a total system. Concurrent engineering problems in connection with multi-supplier, distributed software development are also addressed in the IPTES environment. In the IPTES project the concept of heterogeneous prototyping is proposed as a solution. Each of the development teams may use relatively abstract models of the other parts of the systems as a testbed (environment model) for their own part, yet they can proceed developing their own part full speed by means of advancing the maturity of their part to the next abstraction level(s). The IPTES environment provides a set of tools to help in the process of creating, analyzing, and testing distributed heterogeneous prototypes.     

UDP Hole Punching在视频会议系统中的应用

随着宽带网络技术的发展,基于IP网络的多点视频会议系统得到了广泛的应用.为了解决网络地址资源匮乏的问题,大量企业和部门的网络采用内部IP地址,通过NAT路由器与公共网络通信,但是NAT技术在某些情况下又给用户之间的通信造成了一些困难.深入研究了基于UDP Hole Punching穿透NAT路由器进行通信的方法,在此基础上设计并实现了一套实用的多媒体多点视频会议系统.     

Integration of manufacturing services into virtual environments over the internet

Virtual reality (VR) is a rapidly developing technology that has a wide spectrum of industrial and commercial applications. Networked (distributed or shared) virtual environments (VE) are of growing interest to modern manufacturing industry; a dominating use of networked virtual manufacturing environments (VMEs) is on-line visualisation and collaborative control of 3D information. This has to be supported by real-time data transfer. To meet a broad range of common requirements for Internet-based VE communications, particularly for virtual manufacturing and collaborative design and control, this paper presents a networked virtual environment system that is designed to support networked virtual design and manufacturing. The system is implemented with manufacturing message specification (MMS) standards so as to integrate a range of manufacturing services into networked VEs over the Internet.     

一种基于网络拓扑的蠕虫病毒仿真模型研究

近年来频繁暴发的大规模计算机网络病毒对Internet的安全造成了严重威胁。为了有效地研究网络病毒的扩散、检测与控制,掌握病毒在Internet上的行为过程,本文综合运用拓扑学与计算机仿真的基础理论,设计对一类典型病毒——蠕虫的网络攻击行为进行模拟仿真。在系统设计方面借鉴了传统扩散模型的定性分析方法,以真实的网络拓扑结构为输入,模拟三种不同的扩散机制作用下的蠕虫病毒扩散过程。实验结果表明,通过该模型可以实现对指定计算机网络病毒的更加客观的定量描述。     

Towards agent systems engineering

The term “ ” has became a buzzword these days, not only in academic circles, but also in some computer magazines and application fields of computer science like manufacturing and logistics. Hence, there is a pressing need for a design methodology for multi-agent systems. Or even stronger, there is a demand for an agent engineering technology, which includes computer assistance during the design phases, for the validation of the designed system, and for the implementation of the multi-agent system as a physically distributed system. This status report will introduce the field of multi-agent systems and its design. Three prominent applications will serve as a first motivation of the theme. Based on the ideas of the agent examples a discussion on the term agent will serve as a first motivation of the theme. Based of the theme. Based on the ideas of the agent architecture of an agent, its communication capabilities, and planning in a multi-agent context. After this broad technical introduction the main topic of this work will be tackled. An introduction to five methodologies for the design of multi-agent systems will be given and a new one, the method, will be presented. Eventually a brief discussion about the multi-agent design approaches will be given, the missing correlations to the task definitions will be critizised, and further research directions will be proposed.     

Virtual Video Prototyping

Computing power is an integrated part of our physical environment, and since our physical environment is three-dimensional, the virtual studio technology, with its unique potential for visualizing digital 3D objects and environments along with physical objects, offers an obvious path to pursue in order to envision future usage scenarios in the domain of pervasive computing.We label the work method virtual video prototyping, which grew out of a number of information systems design techniques along with approaches to visualization in the field of architecture and set design.We present a collection of virtual video prototyping cases and use them as the platform for a discussion, which pinpoint advantages and disadvantages of working with virtual video prototyping as a tool for communication, experimentation and reflection in the design process. Based on more than ten cases we have made the observations that virtual video prototypes 1) are a powerful medium of communication in development teams and for communication with industry partners and potential investors, 2) support both testing and generating ideas 3) are particular suited for addressing spatial issues and new ways of interacting. In addition practical use of virtual video prototypes has indicated the need to take into account some critical issues including a) production resources, b) hand-on experience, and c) the seductive power of virtual video prototypes.     

Web-based environment for mechanism simulation integrated with CAD system

The present work describes the architecture of a new approach addressing the sharing of virtual prototypes over the Web with standard programming tools. The usage of standard Web-based technologies leads to easier, effective and more general applications suitable for small and medium size companies with limited resources in that field of research. Designers not only exchange just geometry data, but also more information about design knowledge and design solutions, and collaboration is performed on remote locations. In this work the framework is proposed to model a mechanical product focusing on behavioural criteria. In order to avoid time-consuming virtual model preparation, product variety is defined in single configuration file. The configuration file is covering all the variations, with formalisation of the assembly structure and linking the parts and attributes in uniform way. It enables visualisation of the models from different modelling systems and allows interactive changes and evaluation of the virtual prototype.     

An intelligent assistant for requirements validation

The process of determining user requirements for software systems is often plagued with uncertainty, ambiguity, and inconsistency. Rapid prototyping offers an iterative approach to requirements engineering that can be used to alleviate some of the problems with communication and understanding. Since the systems development process is characterized by changing requirements and assumptions, involving multiple stakeholders with often differing viewpoints, it is beneficial to capture the justifications for the decisions in the development process in a structured manner. Thisdesign rationale captured during requirements engineering can be used in conjunction with the rapid prototyping process to support various stakeholders involved in systems development. CAPS (the Computer Aided Prototyping System) has been built to help software engineers rapidly construct prototypes of proposed software systems. REMAP (Representation and MAintenance of Process knowledge) provides a conceptual model and mechanisms to represent and reason with (design) rationale knowledge. In this paper, we describe how in the context of evolving requirements, the CAPS system augmented with REMAP helps firm up software requirements through iterative negotiations via examination of executable prototypes and reasoning with design rationale knowledge.     

A systematic review of shared visualisation to achieve common ground

This paper reports a systematic review of shared visualisation based on fifteen papers from 2000 to 2013. The findings identified five shared visualisation strategies that represent the ways implemented to process data sharing and knowledge to arrive at the desired level of understanding. Four visualisation techniques were also identified to show how shared cognition is made possible in designing tools for mediating data or knowledge among the users involved. These findings provide research opportunities in integrating rich interactive data visualisation for mobile-based technologies as an effective mean in supporting collaborative work. Finally, social, task and cognitive elements which can be significantly supported by shared visualisation and a guideline for future researchers seeking to design shared visualisation-based systems are presented.