An object-oriented simulation and extension for tandem AGV systems

An object-oriented simulation modelling environment, AgvTalk, is presented to provide flexible modelling capabilities for the simulation of many alternative automated guided vehicle (AGV) systems. The hierarchical features and modularity of AgvTalk create possibilities for the extension and reuse of simulation object components. The detailed behaviour of each object in the AGV system can also be modelled easily and exactly in AgvTalk because there are no limiting modelling constructs. The modelling capabilities of AgvTalk are demonstrated by designing and simulating a conceptually different configuration AGV system, known as the tandem configuration. For the tandem and conventional AGV systems, the characteristics and design methodology in AgvTalk are described. Simulations between the two systems are compared using AgvTalk in a job shop environment.     

机械系统协同仿真环境中软件集成技术研究

于Agent、Adapter技术对协同仿真环境中软件集成技术进行研究,以服务组件的形式建立分布式环境下仿真软件的集成框架,通过面向对象技术对客户端软件调用细节的封装,实现平台与仿真软件松散耦合和平台扩展性。构建了多Agent模式下的客户端组件模型,封装Agent的获取和调用细节,同时对负载平衡算法和并发控制机制进行了设计,解决了多Agent模式下的负载平衡和并发冲突问题。所提出的方案已初步应用到机械系统协同仿真环境中,并取得了较好的效果。     

CAD/CAE协同仿真技术应用研究

通过对主流CAD/CAE软件及其插件和专用接口的研究,分析了协同仿真技术的特点和流程,结合实例阐述了协同仿真的具体步骤、相关技巧以及仿真过程中的注意事项.     

An object-oriented conceptual model of a collaborative product development management (CPDM) system

It is apparent that the development or implementation of a collaborative product development management (CPDM) system in an enterprise should be based on the right understanding of core domain objects, their main attributes, and their relationships to other objects in the product development domain. For this purpose, an object-oriented conceptual model of a CPDM system based on a top-down approach is presented in this paper. For building the conceptual model systematically, this paper proposes the 4P2C modeling views, which are multi-faceted views of engineering information that provides an integrated and consistent perspective on engineering information. The 4P2C stands for product, process, project, participant, cost, and collaboration. Based on the 4P2C modeling views, six sub-models are constructed that eventually constitute a complete conceptual CPDM model. In each sub-model, the decomposition of core domain objects, their main attributes, and their relationships to other objects are represented in detail. A prototype application program along with an illustrative cost calculation example is also presented to demonstrate that the proposed CPDM model will enable enterprises to maintain consistency in product data efficiently throughout the product life cycle.     

产品配置管理系统中数据库关键技术的研究

目的为了有效地组织和管理好机械产品数据和信息,并且提高已有资源的利用率,研究产品配置系统的数据库设计无疑是一项重要的工作。方法提出一种从树状结构过渡到部分网状的产品配置数据结构,并引入到数据库设计中,在PDM的关系数据库管理系统中,实现对产品数据的面向对象表示。结果基于SmarTeam-PDM创建符合于产品配置系统的数据结构,构造一个适合用户需要的数据库。结论采用基于关系数据库的面向对象技术,实现产品配置系统数据库设计,提高了基于PDM的产品配置系统开放性和适应能力,为设计类似系统数据库提供了参考。     

面向对象技术在车辆动力学仿真中的应用

分析了车辆动力学仿真的主要问题,建立了基于面向对象方法的车辆动力学仿真系统的体系结构,分析了系统的类并建立了类图,给出了在车辆动力学仿真中建立usecase和交互图的方法.根据所建立的软件模型,开发了相应的仿真软件.应用本文所开发的软件分别对车辆的直线制动和转弯制动安全性和稳定性这两种工况进行了仿真计算,计算结果符合车辆运行的实际情况.面向对象方法所具有的封装、继承等特点使系统具有结构清晰、扩展和维护方便等特点,为车辆控制系统的开发奠定了基础.     

面向对象的模块化柔性生产线并行设计研究

针对模块化柔性生产线方案设计系统的复杂性,研究了面向对象的并行设计系统。通过把设计过程分解为对系统若干对象的设计,提出了面向对象的模块化柔性生产线并行设计过程模型。在此基础上建立统一的全局数据模型,开发了箱体类零件柔性生产线并行设计原型系统,以支持加工对象的特征设计、工艺规划、系统配置结构设计、模块化机床、刀具等设计的并行运行,并进行了实例验证。     

Agent technology for collaborative process planning: a review

Agent technology has been considered as a promising approach for developing process planning systems and optimizing process plans in a distributed environment. A number of researchers have attempted to use agent technology in process planning for the purpose of integrating systems, tools and algorithms which are geographically distributed. In this paper, the historical background of agent technology is systematically reviewed. A comprehensive review of agent technology and its applications in manufacturing is presented including the applications of agent in scheduling, control, and enterprise integration and supply chain management. The focus of the paper is on how agent technology can be further developed in the support of collaborative process planning as well as its future research issues and directions in process planning. The current research directions in computer aided process planning (CAPP) and issues in traditional CAPP approaches are also discussed. Three agent-based approaches for process planning are presented. Finally, the key issues in developing agent-based collaborative process planning systems are summarized.     

The development of a collaborative design chain reference model for the motorcycle industry

A well-defined and flexible design chain reference model forms the basis for promoting collaborative design chain. The Special Interest Group under the Design Chain Council proposed the design chain operations reference (DCOR) in an attempt to assist enterprises building a design chain modeling frameworks. To date, DCOR version 1.0 only provides preliminary definitions, such as those for major design procedures, and lacks an example of best practices in the industry. Additionally, few studies have attempted this research issue. This study integrates the concepts of design chain, collaborative product design, and collaborative product commerce in a proposed collaborative design chain operations reference model (CDCORM) based on DCOR as a reference for developing a collaborative design chain system in the product lifecycle. The CDCORM consists of four hierarchical levels: collaborative design chain business model; collaborative design chain cooperative model; collaborative design-chain process model; and, a collaborative design chain operational model. Based on project management, the CDCORM has five core procedures-product plan, concept design, detail design, design review, and design amend. This study also assesses the effectiveness of the CDCORM by applying it to the motorcycle industry. In summary, this study extends the DCOR model and proposes a complete collaborative design chain reference model and implements a system in the motorcycle industry as a case study. This case study serves as a best practices example for the motorcycle industry.     

基于面向对象技术的尺寸精度设计专家系统研究

本文采用先进的面向对象技术完成了尺寸精度及配合设计专家系统的建造工作,运用专家系统完成机械设计与制造是比较理想的方法。     

液压机械传动多领域虚拟样机集成与协同仿真

利用Pro／E、ADAMS、EASY5三种软件建立了液机械无级传动系统各子系统模型,完成了ADAMS／EASY5接口变量设计,将各子模型集成为ADAMS／EASY5协同仿真虚拟样机动力学模型。对液压机械无级传动系统纯液压段进行了协同仿真分析,得到了动力传动系统的动态特性曲线。本文的研究结论将为涉及多学科的液压机械无级传动系统的设计过程提供强大的支持,为其应用提供重要的理论依据。     

Reverse engineering employing a 3D laser scanner: A case study

An important step in many manufacturing processes is the definition of the three-dimensional form of an object's shape. A common example is the definition of a designer's model created in clay or wood. A three-dimensional laser scanner offers the advantage of speed and non-contact sensing compared to traditional touch probe sensing. The three-dimensional data produced have been used in a multi-patch reverse engineering program in order to model objects where many types of surface patches, such as quadric and free-form, are blended together on one object. The surface reconstruction algorithms have been demonstrated to provide accurate and smooth surfaces that are suitable for CAD database integration and CNC machine toolpath generation. The algorithms have been implemented in an interactive 3D surface modelling program that produces surfaces compatible with current CAD/CAM systems. The application of the technology to the reverse engineering of a typical injection moulded part is described.     

EDXRD安检系统衍射谱数据库的仿真研究

能量色散X射线衍射(EDXRD)系统在安检领域具有重要的应用前景。基于能量色散X射线衍射原理,以ICDD-JCPDS数据作为初始能谱信息,分析了X射线光源、系统结构、探测器分辨率及物质衰减效应对衍射能谱的影响,建立了与系统特性相对应的衍射谱仿真模型。利用该模型,仿真了不同结构参数EDXRD系统的衍射谱,仿真谱和实际测量结果吻合。在此基础上,仿真了海洛因和NH_4NO_3在不同晶体结构下的衍射能谱,为EDXRD安检系统的识别数据库提供了一种有效的构建方法。     

A collaborative model for capacity expansion of the IC foundry industry

Collaborative project management is becoming a key means of survival for managing the integrated circuit (IC) foundry business. Starting a new IC foundry fabrication project involves complex organizational collaboration and systems integration. In the past, the lack of adequate theoretical approaches to combine parallel systems has led to poor integration of information and poor communication. This paper presents an object-oriented reference model for helping the project managers and the participants to better manage the collaborative relationship and systems integration during the expansion of new IC fabrication foundries. The tool set of the architecture of integrated information systems (ARIS) is applied to describe the interaction between the organization, events, functions, and the systems flow. An object-oriented analysis approach is used to represent the architecture of the collaborative model. A prototype Web-based platform is constructed to demonstrate the model for the capacity expansion of the IC foundry industry and show the improved communication channel.     

反求工程中复杂曲面边界线的自动提取技术

复杂曲面零件表面的几何模型构造是反求工程的研究重点之一 ,根据零件表面的数字化数据提取零件表面的边界是构造零件几何模型的关键步骤。针对完全散乱的、无组织的“点云”数据 ,从工程应用的角度出发 ,提出了一种自动构造曲面边界曲线的方法 ,它分为两个步骤 ,首先 ,利用分割方法得到一条能包围曲面的所有数字化点的曲线 ,然后将该曲线模拟为橡皮筋 ,通过能量最小原理自动修正曲线得到理想的曲面边界。实践证明 ,通过该方法得到的边界曲线能满足工程应用的需要     

面向再制造的基于PRO/E的仿真技术研究

介绍了以手动变速箱、减速器为模型的拆卸仿真技术。首先利用PRO/E中的Mecha-nism机构仿真模块,在Pro/Engineer环境下执行运动仿真,实现变速箱的装配运动仿真;再利用VC下的MFC的对话框技术,设计面向再制造的拆卸仿真界面,通过界面可实现产品拆卸序列的规划、实现产品拆卸动作和拆卸再制造性评估,最后编写相应的Pro/Toolkit算法程序,实现产品的目标拆卸仿真。提出了应用层次概率模糊认知法规划产品的拆卸序列和产品拆卸性评价的方法,并给出了相应的函数及算法。     

基于虚拟现实的交互式自行车模拟器研究

交互式自行车模拟器是集动感及力觉提示、力学仿真以及计算机图形学等技术于一体的动感模拟器系统。本文提出了由运动生成及力觉反馈系统,运动学／动力学仿真系统、视景仿真系统、地形数据库系统组成的自行车模拟器系统总体结构,并详细地介绍了各个子系统的功能和关键技术。     

A study of advanced die-casting technology integrating CAD/RP/FEA for Zn castings

By means of computer aided engineering (CAE) is developed an integrate CAD/RP/FEA system to assist reducing the lead-time of die-castings design and upgrade the die-casting manufacturing technology parameters for zinc castings. The rapid die-casting methodology developed integrates: conceptual design; virtual prototyping (VP), rapid prototyping (RP), P-Q² technique, finite element analysis (FEA) to improve die-casting process and numerical control (NC) to upgrade die-casting manufacturing parameters. Thermal fluid flow and heat transfer modelling are performed to simulate die-casting manufacture technology to predict defects, increase yield and to improve the manufacturing process. An improved die-casting manufacturing process supported via CAD/RP/FEA technologies and NC control are demonstrated through a die-casting case study to manufacture sound zinc die-castings and conclusions are presented.     

一种基于CT图像反求技术的实体几何造型方法

基于 CT图像的反求是反求工程中的重要内容 ,由 CT图像反求重建出的表面模型只包含了表面几何信息 ,而实体几何模型具有完备的几何和拓扑信息。针对 CAD造型系统中实体模型的特点 ,本文提出一种基于 CT图像反求技术的实体几何造型方法。应用 CT图像反求技术重建出物体的三维表面模型 ,在重建出的拟合曲面三角片序列的基础上 ,采用半边结构来表达重建的表面模型 ,并将该过程作为本研究所开发的特征造型原型系统 3D-Modeler2 .0中的一种造型方法     

基于仿真的生产系统规划技术研究

现代生产系统是复杂的离散制造系统,传统生产线的设计过多地依靠经验和手工演算,缺少科学性,很难达到预期结果.其中生产线的设计与生产线设备的利用率、产品的生产时间和生产线的效率等密切相关.采用先进的生产线规划与仿真技术,可以对生产系统的性能进行评价,在生产规划的早期对其系统进行优化与调整,以便得到较高的生产率.以某发动机缸盖的生产线的规划为对象,采用面向对象的离散系统仿真软件eM-Plant软件构建生产线仿真模型并进行了生产线生产能力、设备的利用率和生产效率的分析,为生产线的优化提供了技术依据.在此基础上采用生产线规划软件FactoryCAD构建了发动机缸盖生产线的3D数字模型,为发动机缸盖生产线的设计提供了技术依据.