虚拟数字制造的建模与模拟研究

本文描述了虚拟数控零部件制造车间的建模与模拟结构，分析了设备模型和材料模型，虚拟车间模型，用户操作，数控零部件模型，虚拟车间模拟，模拟接口等模块的建立，讨论了虚拟数控制造的实时性和并行控制问题。     

船体零部件制造数字化车间物流仿真技术研究

将船体零部件制造与物流仿真技术相结合,借助Flexsim物流仿真软件构建了某船体零部件制造数字化车间的场地、生产对象以及加工设备的仿真模型.通过模拟仿真,研究了船体零部件数字化制造车间的物流管理技术.     

船体零部件制造车间数字化物流现状及标准研究

以船体零部件制造车间生产物流为研究对象,在智能造船背景下,分析我国船厂船体零部件制造车间数字化物流现状及发展趋势。结合我国现行零部件制造车间生产物流标准现状,提出车间数字化物流标准需求,为数字化车间建立奠定一定基础。     

虚拟车间动态重构模型的研究

阐述了敏捷制造模式下，车间的功能除了具有常规的生产管理和控制功能外，还具有实现单元动态重构的功能和通过网络对外合作的功能。在分析了虚拟车间动态重构的系统的关键技术的基础上，提出了基于多代理机的虚拟车间动态重构模型，讨论了Ａｇｅｎｔ之间的协商机制。     

基于VERICUT的虚拟制造技术研究

介绍数控加工仿真软件VERICUT的作用与功能,并通过具体实例阐述利用该软件进行数控虚拟制造的一般步骤,证明VERCUT软件在虚拟制造技术中的优越性。     

美国航天工业中精密检测工艺的崛起

近年来,精密检测工艺在美国航天制造业中正日益发挥着重要的作用,从事产品质量检测业务的有关公司正致力于凭借数控计算机和监控计算机高效率地测量航天兵工厂生产的零部件,并凭借高精度监测设备大幅度地提高检测航天产品的能力。本文以美国伊利诺斯州一家私人公司——马尔特克斯公司为实例作一介绍。 该公司是一家拥有检测车间的私人公司,其车间里安装有高精度检测设备,主要业务是检测美国国内专业部门(通用电气公司、普罗特和怀特尼诸公司)制造的飞机零部件。该公司承包喷气式战斗机发动机的裸金属环圈、密     

CAM-CNC一体化

虚拟与真实的无缝连接实现精确的加工模拟,提高一次性加工成功率随着制造业的日趋成熟,数控加工技术的不断普及和深化,CAM加工编程技术和CNC生产制造系统这两个个体已经不是制造业者最关心的热点。如何优化加工方法,提高生产力,降低成本,掌控制造的每个细节逐渐成为了大家讨论的焦点。在今     

船体零部件制造车间数字化物流参考模型标准研究

随着物联网及智能制造技术的发展,船舶制造企业的转型升级也是十分紧迫的,船舶制造是典型的离散制造,具备场地大、流程复杂等特点,零件数量更是达到百万量级,船体零部件制造车间物流工作是提高生产效率和节约经济成本的关键环节。本文对船体零部件制造车间物流系统的体系架构和系统组成开展研究,建立相应的参考模型,形成相应标准供船舶制造企业在进行转型升级、场地改造、搭建数字化物流等工作时参考。     

Alliance车钩内腔装配体约束关系求解

虚拟装配仿真作为虚拟制造实施的核心技术之一,其主要任务是用可视化手段研究和解决产品的可装配性问题。文中在Pro/E参数化建模的基础上,应用其装配模块,以Alliance车钩各零部件模型为应用对象,进行内腔装配体约束关系求解。     

基于智能Agent资源导航的虚拟制造组织构建机制研究

为支持网络经济下的制造企业/组织能够构建和运作虚拟制造组织(Virtual Manufacturing Organization,VMO),在构建了智能Agent模型的基础上,分析、探讨了基于智能Agent的资源导航机制和友元资源搜索定位的VMO构建机制,并运用该机制在车间层面搭建了智能制造原型系统,从原理上验证了VMO构建机制的可行性和有效性。     

虚拟机械加工环境的建造

在研究虚拟现实技术，数控加工技术的基础,开发出一个虚拟加工环境，其中主要包括车间、机床、夹具等场景，该环境包括三坐标铣削加工中心等５台机床，机床实现了仿真加工能力，车间提供了用户漫游功能。同时该环境实现了对零件可加工性、加工参数合理性的评价。     

FMS中CAPP与CAM集成技术的研究

介绍了一个适用于FMS的CAPP／CAM集成系统。它由创成法CAPP系统，NC自动编程系统和它们之间的接口等主要部分组成。系统采用基于特征的零件描述方法作为集成环境下统一的零件信息模型。由CAPP系统生成的工艺规程，通过接口文件自动传输给NC编程系统，经过特征识别后，从特征NC程序库中调用相应的特征数控程序，实现NC自动编程，为检验NC程序的错误，系统还具有刀具轨迹仿真功能，系统用户界面友好，经加工验证，可用于生产。     

Virtual prototyping and manufacturing planning by using tri-dexel models and haptic force feedback

This paper presents a new method of using the tri-dexel volumetric models and a haptics force feedback for virtual prototyping and manufacturing planning. In the proposed method, the initial polyhedral surface model is converted to a tri-dexel volumetric model by using a depth-peeling dexelization algorithm. In the virtual prototyping process, the tri-dexel volumetric model is updated by the swept volume of a moving cutter via a haptic force feedback interface device. A collision detection algorithm is proposed for the virtual sculpting and the pencil-cut planning with real-time haptic force feedback to the users. Tool paths are generated for machining the virtual sculpted parts via the simulation and verification on a virtual CNC machine tool before they are actually machined. Computer implementation and practical examples are also presented in this paper. The proposed method enables the haptic-aided virtual prototyping and manufacturing planning of complex surface parts.     

Virtual prototyping and manufacturing planning by using tri-dexel models and haptic force feedback

This paper presents a new method of using the tri-dexel volumetric models and a haptics force feedback for virtual prototyping and manufacturing planning. In the proposed method, the initial polyhedral surface model is converted to a tri-dexel volumetric model by using a depth-peeling dexelization algorithm. In the virtual prototyping process, the tri-dexel volumetric model is updated by the swept volume of a moving cutter via a haptic force feedback interface device. A collision detection algorithm is proposed for the virtual sculpting and the pencil-cut planning with real-time haptic force feedback to the users. Tool paths are generated for machining the virtual sculpted parts via the simulation and verification on a virtual CNC machine tool before they are actually machined. Computer implementation and practical examples are also presented in this paper. The proposed method enables the haptic-aided virtual prototyping and manufacturing planning of complex surface parts.     

An Internet-enabled image- and model-based virtual machining system

Virtual reality (VR) can be described as a four-dimensional (4-D) simulation of the real world, including the 3-D geometry space, 1-D time and the immersive or semi-immersive interaction interface. VR applications in mechanical-related research areas are becoming popular, e.g. virtual layout design, virtual prototyping, Internet-based virtual manufacturing, etc. However, research in VR applications is facing conflicting requirements for high rendering quality and near real-time interactivity. This paper represents an Internet-based virtual machining system that builds an integrated VR scene, which combines images and models, to overcome the above conflicts. This research is divided into three parts: first, image mosaics techniques are used to implement an Internet-based virtual workshop, which is an image-based virtual scene. The method of obtaining original sequential images, the principle of image mosaics to realize automatic seamless stitching, and projection transformation matrices to reconstruct a closed inward-facing space are presented. Secondly, a model-based virtual milling machine has been constructed with three detailed approaches: a category-based dynamic graph structure to support collision detection, a relation-oriented collision detection method to improve the efficiency of collision detection, and a dynamic modelling method to model a dynamic workpiece object. Finally, an Internet-based virtual milling system, which is the integration of the image-based virtual workshop and the model-based virtual CNC machine, is constructed using the reposition method to achieve visual consistency of the virtual objects and images. This system, which includes an integrated scene, combines the advantages of image-based VR and model-based VR. Consequently, this system has both high rendering quality and good real-time interactivity.     

模具生产车间情景仿真建模

针对模具生产过程的复杂性,一般的数学建模又难以全面描述模具生产车间的运作过程,采用面向对象的仿真技术对模具制造系统进行建模,并通过与模具企业的ERP生产管理系统模块建立数据接口,以实际生产数据驱动仿真运行。提出了构建模具制造过程情景仿真系统的总体思路和方法,开发了某模具企业某车间的情景仿真系统,并通过该车间实际模具交货期和仿真系统预测的模具交货期进行对比,验证了该情景仿真系统的有效性。     

Capacity assignment of virtual manufacturing cells by applying lot size harmonization

Decentralized manufacturing cells minimize the lead time of products. However, technical and economical restrictions can prohibit the installation of permanent cells. A possibility to overcome these restrictions is 'virtual manufacturing cells'. These cells are defined by production teams who are responsible for the complete process of a group of products. Unlike permanent cells, the layout can be kept in a workshop structure. This results in a double competition between the orders and between production teams for the use of capacities. A new approach to solving this double competition is to limit the occupation time of capacity units. Combined with alternating access to resources by the production teams, this ensures a clearly defined order sequence. A successful way to achieve the limitation of occupation time is the harmonization of lot sizes. This analytical method should be supported by simulation to consider the dynamic behaviour. The authors have developed a simulation reference model to limit the expense of simulation studies for this purpose.     

快速编程NC模板的开发与应用

在建立数控加工知识库的基础上,应用Cimatron软件建立了对应的程序模板与零件加工模板．应用模板可以快速完成程序编制,提高数控编程的质量与效率,并实现基于知识的加工,规范工艺路线与工艺参数．并以实例说明了NC模极的创建与应用．     

Detailed short term simulation of workshop operations

This paper is concerned with prediction of machine utilization and specific work-batch completions in a manufacturing workshop which employs dispatching rules for work loading. Predictions from a simple iterative computer simulation are compared with those from a real-time manual simulation. The computer simulation is varied by adjusting the number of iterations and the allocated process capacities, and conclusions are drawn on the best method of achieving improvement in the fit of the model. The technique is applied on a microcomputer, but it can be implemented on a mini or mainframe if manufacturing information data flies currently exist. It will be of value in short term allocation of flexible resources, in supplying detailed predictions of individual work batch completions to improve service levels or in short term planning of maintenance to coincide with machine idle periods.     

Integrated simulation application design for short-term production scheduling

This paper focuses on the development of an integrated short-term production scheduling simulation model for a complex manufacturing operation. The decision making tool has a front-end user data interface built with Microsoft Access and Visual Basic for Applications software. The model assists production planners to make informed decisions on how best to schedule simultaneously two lanes of daily or weekly production on a unique plastic parts manufacturing line. The advantages and disadvantages (model weaknesses) of using the simulation model, especially as a scheduling tool, are discussed. In this particular application, we find that the advantages far outweigh the disadvantages.