Rapid one-of-a-kind product development

In today’s global market, more and more manufacturing companies have realised that the ability to quickly develop a customised product in an economic and efficient way is critical for them to survive in the keen competitive international market, particularly for one-of-a-kind production (OKP) companies. A new generation of OKP systems needs to be developed to maintain competitiveness in the global marketplace and to improve the ability to rapidly combine the strengths of manufacturing partners to meet market needs. In this paper, the main objectives of rapid OKP development in the global manufacturing environment are discussed. The background of recent approaches for rapid development of OKP products is reviewed. After systematically reviewing the existing OKP systems and recent developments of new technology and systems, the authors discuss current issues and requirements for developing a new generation of OKP systems for rapidly producing OKP products. At the end of this paper, a reference system structure is proposed for rapid development of OKP products in the global manufacturing environment .     

A framework for generating product production information for mass customization

As mass customization companies grow their business, the amount of custom information required to run the business increases. This paper proposes an information technology (IT) framework to solve this problem through automatic generation of information. The framework uses the concept of information templates or models and a rule-based system to generate manufacturing instructions. The templates combine the knowledge of bill-of-materials and resources while applying constraints to ensure the resulting custom product conforms to performance specifications. The feasibility and effectiveness of the framework and concepts are empirically validated by a case study implementation at a company that mass produces customized windows and doors in Calgary, Canada.     

Rapid one-of-a-kind production

To shorten the product development cycle time and reduce the cost at the same time, which is very critical for the survival of those small and mid-sized one-of-a-kind production (SMOKP) companies, various computer communication, simulation and computer aided engineering and management techniques have been widely used in these SMOKP companies. However, according to our study, the applications of these advanced computer technologies in these SMOKP companies are lack of system integration and synergy, which result in communication errors, reworks, duplications and hence a longer product development lead time and a higher cost. To solve this problem, an inter/intranet based computer aided rapid product development system is presented in this paper. This system consists of a number of inter/intranet based computer models or subsystems for supporting rapid development of a one-of-a-kind product. It also employs a novel concurrent product development strategy called “prototype based incremental product development strategy” and an integrated product data structure called “product production structure”. Some industrial implementations of the proposed system, product development strategy and product data structure are also reported in the paper.     

Rapid one-of-a-kind production

To shorten the product development cycle time and reduce the cost at the same time, which is very critical for the survival of those small and mid-sized one-of-a-kind production (SMOKP) companies, various computer communication, simulation and computer aided engineering and management techniques have been widely used in these SMOKP companies. However, according to our study, the applications of these advanced computer technologies in these SMOKP companies are lack of system integration and synergy, which result in communication errors, reworks, duplications and hence a longer product development lead time and a higher cost. To solve this problem, an inter/intranet based computer aided rapid product development system is presented in this paper. This system consists of a number of inter/intranet based computer models or sub-systems for supporting rapid development of a one-of-a-kind product. It also employs a novel concurrent product development strategy called “prototype based incremental product development strategy” and an integrated product data structure called “product production structure”. Some industrial implementations of the proposed system, product development strategy and product data structure are also reported in the paper.     

Object-Oriented Petri Nets with Changeable Structure (OPNs-CS) for Production System Modelling

We propose object-oriented Petri nets with changeable structure (OPNs-CS) in this paper for effective modelling of production systems with changing structures. Two mechanisms for carrying out the structural changes in OPNs-CS are defined. One is for the modification of message passing relationships between distinct OPNs and the other is for adding of OPNs to, and the removing of OPNs from, a model. A case study is provided to show that OPNs-CS can cope with both the uncertainties which may exist during the model-building phase of a one-of-a-kind production (OKP) system and the structural changes of the system which often occur while the production system is in operation.     

OKP产品开发模式特征分析及实现方法研究

随着企业越来越关注客户需求,力求达到对市场的快速响应,单件产品生产(OKP)成为本世纪一种新的制造范例。OKP的高度定制化及其如何快速满足顾客需求是困扰OKP企业的难题所在。分析OKP生产模式的基本思想,研究这种产品开发模式的重要特征,提出一种在全球制造环境下实现OKP产品快速开发的具体方法。为我国OKP企业成功实施产品开发、提高企业竞争力提供了借鉴。     

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.     

A decision support system for rapid one-of-a-kind product development

A decision support system (DSS) is a specific class of computerized information systems that support decision-making activities. Such a system has become paramount in supporting manufacturing activities with the development of World Wide Web (WWW) technology in recent years. The research and development of a knowledge-based DSS dedicated to rapid one-of-a-kind products (OKPs), however, has, to the author’s knowledge, rarely been directly studied. This work presents a knowledge-based DSS for supporting decision-making activities in developing OKPs using broad knowledge base content. The underlying architecture of the proposed system is a system that manages and optimizes the data, information and knowledge in the product development process. A knowledge structure model is proposed in this paper, and a comprehensive set of expert knowledge and analytical/numerical methods are integrated into the system to automate intelligent decision-making. Case studies have shown that the knowledge-based DSS is able to help OKP companies develop new products more quickly by sharing optimization tools, information and knowledge to reduce possible errors and rework.     

Automatic control of a One-of-a-Kind Production cell

This paper reports the outcome of a research project which aims to solve the problems in automatic control of the shop floor in One-of-a-Kind Production (OKP) through developing a prototype control system for an experimental OKP cell at the laboratory. The main problems in automatic control of the shop floor in OKP are the frequent changes of product structure or type and consequent changes of production system configuration. These changes in OKP make it necessary to have a highly flexible and robust automatic control system. To resolve the problems, a distributed control system has been developed at the CIM laboratory of the Department of Production, Aalborg University, Denmark. This control system has enough flexibility and robustness to cope with the aforementioned changes in OKP. To support the design and implementation of the control system, several concepts, algorithms and control principles, such as task logic routes, address code of production resources, automatic task decomposition algorithm, generic control modules and distributed control principles are also proposed in this paper.     

全自动塑钢门窗三位热熔焊接机的研究与开发

为促进塑料门窗优质高产、全面普及,研制出新型的全自动塑钢门窗三位热熔焊接机。文中阐述了总体方案;解决了研发过程中的一些技术问题,提高了机器的自动化水平和可靠性;采用正交试验法确定了该机最优焊接工艺参数;最后介绍了"┏┳┓"型焊接实例,并分析其焊缝形貌特征。该机适用于塑钢门窗焊接工序,具有结构紧凑、自动高效等优点。     

基于结构预映射的产品建模

零件建模和装配建模是产品建模的两个方面,对制造企业的竞争力有重要影响。在当前的计算机辅助设计系统（Computer-aided design,CAD）中,尽管两者已高度集成,它们在过程层面仍然存在相互割裂的现象。为此,提出一种基于结构预映射（Structure pre-mapping,SPM）的产品建模方法。首先对产品建模过程及SPM进行系统分析,明确实现SPM需要完成的主要任务;其次,详细阐述SPM的内涵,并对其进行形式化定义,以便于在CAD系统中描述;第三,基于前期发展的装配特征偶概念,对存在于设计者头脑中的设计意图（表现为抽象配合结构和配合行为）进行系统建模,形成实现SPM的基础;第四,提出基于SPM的产品建模原理,进而展示相应的框架,并分析框架的功能模块及其实现方法;最后,通过HP发动机空气过滤器头部组件的产品建模实例论证方法的可行性。该方法可在过程层面上提高产品建模的集成程度,对于现有CAD建模理论和技术体系的丰富和发展有一定的积极意义。     

Research of design and analysis integrated information modeling framework for multibody mechanical system: with its application in the LHD design

Many complex mechanical products can be considered as multibody systems; 3D computer-aided design (CAD), multibody dynamics, finite element-based strength and fatigue analyses, optimization, and other CAE tools, are often used to develop this kind of product. But design is difficult and challenging because of information inconsistence among different engineering domains, and isolated information model islands exist. Lots of research are attracted to design and analysis information integration, but attentions are mainly focused on integration of CAD–finite element analysis (FEA), supporting the bottom-up design principle, while multibody dynamics analysis for analyzing global performance of a mechanical system is rarely considered, which follows the top-down design principle. In this paper, a novel multilevel system representation modeling framework for supporting both bottom-up and top-down or mixed design methods is proposed. It can integrate the product design CAD models with multibody dynamics, finite element-based strength and fatigue analyses, realizing a CAD–dynamic–FEA–fatigue analysis integration. It can also support data exchange and transfer in multidomain analyses. The framework is illustrated with a case study of a load haul dump (LHD) design using currently available software tools. Furthermore, a design case study of the working unit of the LHD is given to highlight the applicability of the modeling framework for multibody mechanical systems. It has been demonstrated that the framework can describe information exchanging and integration among CAD, FEA-based strength and fatigue analyses, and multibody dynamics analysis during a multibody mechanical product design process.     

大型单件小批生产的计划与控制模式

大型单件小批生产是大型企业集团的典型生产模式之一,这类企业的生产计划与控制是企业管理的重要组成部分,本文在深入研究各种生产计划与控制模式的基础上,提出了网络计划和MRP计划相结合的一种实用模式,并简要介绍支持该模式和HEC－PPC系统,从而为大型单件小批生产类型企业的生产计划与控制问题,提出了一种可行的解决方案和途径。     

ATmage16在电动门窗实验台上的应用研究

为了更好地满足人们对汽车整体性能不断提高的要求,设计了控制凌志LS400轿车电动门窗工作的控制器。介绍了以ATmegal6单片机为核心的控制器的设计思路、控制方式以及硬件电路设计和程序设计的要点。该控制器可用于各种速度／温度控制装置,对进一步研究电动门窗等汽车电器系统具有一定的启发作用。     

基于产品全生命周期的产品规划建模与应用

市场竞争的不断升级迫使企业将产品价值的挖掘延伸至产品的全生命周期,这为企业带来了更多的产品创新空间和盈利机会,但同时也带来了产品决策的难题。首先以设计域理论为基础建立了一个能够有效表明基于全生命周期系统化特征的产品规划建模框架,以确保产品决策能够有效地融合设计人员的产品设计理念、市场人员对产品需求的分析、生产人员对产品实现过程的分析以及售后服务人员对产品服务过程的分析;接下来,以产品进化设计为研究对象,提出了基于全生命周期的产品规划所必须依赖的决策指标体系和有效表明其权衡取舍机制的建模方法;最后通过在家用轿车产品上的应用,具体表明了方法的有效性和实用价值。提出的方法明确了企业不同的参与者在产品规划过程中需要进行信息交互的具体内容,建立了以不断完善产品信息建构体系为导向的决策机制,是一个符合企业实际需要的系统化方法。     

CAD系统中三维实体建模及在教学中的应用

三维建模是应用CAD系统进行产品设计的重要步骤。提出了一种新的三维建模方法——折叠法，应用其概念和原理可以开发出先进的三维建模CAD系统。该系统可应用于机械制图课中并对教学改革产生深远的影响。     

基于XML的CAD系统和虚拟装配系统之间的数据转换

针对计算机辅助设计系统和虚拟装配系统之间的模型转换问题,提出了基于特征的统一的产品层次信息模型,采用XML中性文档和三角面片模型文件,通过信息分解的方法,分别将在产品建模系统中建立的产品层次信息模型中的装配信息和几何拓扑信息与三角面片信息通过数据转换接口转换到虚拟装配系统中,并在虚拟装配系统中通过映射关系进行模型重构,较好地解决了计算机辅助设计系统和虚拟装配系统之间信息共享的问题,通过实例验证了研究成果的可行性。     

钢坯吊具集成设计系统的研究与开发

基于计算机辅助技术(Computer-Aided Design,CAD)和计算机辅助工程(Computer-Aided Engineering,CAE)集成技术,为实现机械产品的设计流程化、自动化,将三维参数化CAD/CAE系统及输出功能集成到统一界面,形成了开放式的结构设计和分析系统.以钢坯吊具为例,介绍了钢坯吊具集成设计系统的框架组成、设计方案及流程,为大型机械结构的集成设计系统提供开发思路,有利于产品的标准化、系列化及提高产品的科学化管理.     

工艺规划为核心的产品协同研发生产平台

为实现具有市场竞争力产品的高端研发,并具备较高的质量及成本控制能力,文中提出构建以工艺规划为核心的产品数字化研发生产平台的解决思路.平台框架包含计算机辅助设计、产品数据管理、计算机辅助工艺规划和协同制造模块;通过工艺与设计、生产两端的数据共享,实现设计、工艺数据和生产的高效协同;通过工艺规划方案的功能描述,展现了一个为...