虚拟现实环境下产品装配定位导航技术研究

基于自由度归约方法进行约束分析，在理解与识别设计者的装配操作和意图基础上，通过空间几何角度分析，根据装配关系建立装配约束关系树，实现了虚拟现实环境下的产品装配的定位导航，该方法在汽车发动机的虚拟装配中得到了较好的应用。     

基于虚拟现实环境下的装配技术的探讨

介绍了虚拟现实技术的概念和特征;讨论了虚拟装配技术的定义与分类、虚拟装配过程以及装配建模技术、装配规划技术、装配评估、实时图形处理技术和干涉检验技术等;分析虚拟现实技术在制造业中的应用并对其发展趋势进行了简单的阐述.     

虚拟现实环境下交互式船舶装配序列规划研究

针对传统装配序列规划方法解空间大、模型简单的问题,提出了应用虚拟现实技术解决船舶装配序列规划问题的方法。该方法分为虚拟拆卸和方案评价两个阶段,分析了虚拟装配平台上进行虚拟拆卸的基本流程和关键技术——虚拟环境下的实体模型表达和基于装配约束的运动导航。建立了船舶装配序列评价模型,确定了零件重量、装配时间、装配稳定性和装配过程难度等面向手工装配的评价指标。最后,用某船舶机舱区域的规划实例进行了验证,结果表明该方法生成的装配序列对实际船舶装配生产具有指导作用。     

产品装配分析环境的构建

采用Visual C 编程语言,在现有CAD系统的基础上,以Object ARX为开发工具,建立了产品装配分析系统基本结构,可直观演示人机交互拆、装过程,分析装配几何体设计中的缺陷,提取相关装配特征信息,进行装配顺序分析和工艺规划。在Open Inventor虚拟现实软件开发包的基础上,开发了虚拟装配环境,构建了虚拟装配系统的结构框架,实现了从CAD环境到虚拟装配环境产品几何模型数据的传递,演示了产品在虚拟环境下的拆卸过程。     

虚拟现实技术在机械产品装配中的应用

从虚拟现实技术的角度,研究分析虚拟装配的相关技术及虚拟装配系统的设计流程;结合发动机曲柄连杆机构给出虚拟装配的一般步骤;指出成功完成虚拟装配的关键在于虚拟手的操作,提出虚拟手抓取的满足条件.     

面向机器人装配的产品装配特征

基于机器人装配的特点 ,从 3个方面描述了产品的装配特征 ,将产品的装配特征表达为零件级特征、关联功能级特征和工艺级特征 ,据此特征可便利地进行产品的装配规划和可装配性评价。介绍了产品装配分析系统的结构框架 ,它可为后续生产活动提供信息。     

基于特征的产品装配建模系统

分析了特征概念在装配领域的意义和作用。描述了表达产品自顶向下设计过程的装配模型的内容,建立了一个基于特征的产品装配模型,并在此基础上给出了系统的具体实现和应用实例。     

I-DEAS平台下基于装配特征识别的装配技术

提出一种基于装配特征识别的装配技术。根据装配设计过程中的工程装配语义建立装配知识库。装配时,设计者只需选取待装配件,系统就会根据待装配件的装配特征搜索装配知识库并识别出零件间的工程装配语义,然后转化为系统能理解的装配关系。开发了基于I—DEAS的装配平台,实践证明,这种装配技术能重复使用装配信息,有效提高装配设计的效率。     

产品装配特征的分类与表达技术的研究

将产品的装配特征表达为零件级特征、关联功能级特征和工艺级特征的集合 ,详细描述了各个特征的表达方式。介绍了产品装配分析系统的结构框架 ,它可对产品装配各环节进行分析并为后续生产活动提供信息 ,为并行环境下的信息集成奠定基础。     

虚拟环境中产品装配技术的研究

本文介绍了虚拟环境中产品装配的一般理论、方法以及所采用的一些技术,并着重讨论了实体模型建立、装配规划 及装配顺序的优化和评价等问题,指出了一般虚拟装配系统的不足。     

The application of virtual reality to tasks in manufacturing and assembly engineering

Virtual Reality is a developing technology for which a range of applications are heing explored by different international research groups. This paper describes recent research in the application of Virtual Reality to two important manufacturing and assembly tasks which have a direct influence on the speed of introduction of new products. The tasks are the production of planning documentation for assembled products and the design and planning of the cable harnesses which form part of all electro-mechanical assemblies. The research completed so far demonstrates the potential of Virtual Reality, even at its current stage of technological development, to make a significant contribution in both these cases.     

虚拟现实中基于用户的数字化产品开发模式

产品数字化技术是目前研究的热门,通过对现代产品开发模式的探讨,提出了基于用户的产品数字化开发模式(DPDTC),并对其实现的功能和核心问题作了初步说明。     

基于虚拟环境下的产品开发技术研究

虚拟产品开发技术不仅可真正实现设计与过程的集成,同时它还可促进异地分布式协同产品开发的实现。本文介绍了虚拟产品开发的技术内涵、研究内容,结合以往对虚拟产品开发领域的研究成果,对虚拟产品开发的体系结构进行了初步探索。     

Constrained behavior manipulation for interactive assembly in a virtual environment

Interactive assembly based on virtual reality offers users an opportunity to interact with a virtual prototyping rather than a physical one and to validate assembly performance of products in a realistic way. Such evaluations could be available very early in the product development process ahead of any physical prototyping. The reduction or elimination of physical prototyping needed for assembly performance validation can substantially shorten the product development cycle and reduce development cost. Although virtual reality technology provides users an intuitive and immersive 3D interactive interface, it tends to be inaccurate because humans have difficulty in performing precise positioning tasks. Therefore, it is necessary to implement effective motion manipulation for assembly operations so that users can perform precise positioning efficiently in virtual assembly systems. This paper presents a constrained behavior management approach that realizes assembly relationship recognition, constraint solution and constrained motion for interactive assembly in a virtual environment. A constrained behavior manager (CBM) has been developed and applied in virtual assembly systems. Test cases confirm that constrained behavior manipulation proposed in this paper not only increases the efficiency of assembly relationship recognition, but also facilitates assembly interaction in a virtual environment.     

虚拟产品设计过程中零部件之间的隶属关系问题

针对虚拟产品设计过程中，零部件之间的隶属关系问题进行了研究，指出了虚拟产品设计过程中产品零部件之间的隶属关系不明确这一问题产生的原因，并研究了用计算机操作系统中，“树形目录结构”管理文件的原理来表示虚拟产品设计过程中零部件之间的隶属关系的方法.     

虚拟装配环境中的装配模型表达技术研究

针对虚拟装配领域常用产品模型表达方法的信息完整性与操作效率之间的矛盾,提出面向过程的装配模型复合表达法,并应用于集成虚拟装配系统。该方法的装配模型主要包括层次结构的装配树模型、复合表达的零件模型、面向过程的约束模型和路径模型。零件采用B—rep、面片和凸包等3种模型复合表达。集成虚拟装配系统的测试结果表明,该模型表达方法能够满足虚拟装配过程的信息表达要求,并能较好地支持虚拟装配过程中的实时交互。     

基于装配工艺规程的产品虚拟装配技术

描述了VPD环境下的产品装配模型，建立了产品装配模型的数据结构，定义了产品装配模型系统的结构组成及模块功能；参照加工工艺规程，提出了虚拟产品装配工艺规程的概念；结合挤塑模和轻型客车的虚拟装配、活塞连杆机构及发动机的运动过程，实现了基于真实动画感的VPD环境下的产品虚拟装配及虚拟工作过程仿真。     

A novel optimal assembly algorithm for haptic interface applications of a virtual maintenance system

A virtual maintenance system in a virtual environment can be used to simulate a real-world maintenance system. The efficiency of the simulation depends mainly on the assembly/disassembly task sequence. During simulation, path planning of mechanical parts becomes an important factor since it affects the overall efficiency of the maintenance system in terms of saving energy and time. Therefore, planners must consider the path-planning factors under constraints such as obstacles and the initial/final positions of the parts, as well as the assembly sequence such as number of gripper exchanges and direction changes. We propose a novel optimal assembly algorithm that considers the assembly sequence of mechanical parts and the path-planning factors for a virtual maintenance simulation system. The genetic algorithm is used to determine the optimal sequence of parts to minimize the numbers of gripper exchanges and direction changes, as well as find a repulsive force radius by using the potential field method to generate the shortest optimal distance for transferring each part during the assembly operation. By applying the proposed algorithm to a virtual maintenance system, users can be haptically guided to the optimized assembly solution during mechanical parts assembly operations. This paper was recommended for publication in revised form by Associate Editor Jong Hyeon Park Christiand received a B.Eng. degree in Mechanical Engineering from University of Indonesia in 2006. He then went on to receive his M.Eng. from Gyeongsang National University in 2008. He is currently a member of engineering staff at Electronics and Telecommunication Research Institute (ETRI) in Daejeon, Korea. Jungwon Yoon received the B.S. degree in precision mechanical engineering in 1998 from the Chonbuk National Univ., Korea, and the M. S. degree in the Department of Mechatronics in 2000 from Gwangju Institute of Science and Technology (GIST), Kwangju, Korea, where he received the Ph.D. in 2005. He had worked as a senior researcher in Electronics Telecommunication Research Institute (ETRI), Daejeon, Korea, and a visiting researcher at Virtual Reality Lab, the Rutgers University, U.S.A, from 2001 to 2002. In 2005, he joined the School of Mechanical & Aerospace Engineering, Gyeongsang National University, Jinju, Korea, where he is currently an assistant professor. His research interests include virtual reality haptic devices & locomotion interfaces, and rehabilitation robots.