【作者】 胡勇；

【导师】 范秀敏；

【作者基本信息】 上海交通大学 ， 机械制造及其自动化， 2013， 博士

【摘要】 面向数字样机的设计评审是复杂产品开发过程中的重要环节，随着产品功能和结构的日趋复杂，产品研发及制造过程中的分工越来越精细，给产品数字样机的设计评审和质量风险管理带来了困难，基于网格的协同虚拟现实环境为处于异地设计环境下进行复杂产品数字样机设计评审提供了可行的解决方案。虚拟现实技术经过十余年的发展，已在越来越广泛的领域中得到应用，成为设计公司、生产企业提高竞争力的一项重要手段；网格技术作为一种前瞻的面向广域网的分布式计算模式，是传统的并行和分布式计算在深度和广度上的拓展，为虚拟现实应用在更广的范围内利用资源和提供服务成为可能。为支持异地复杂机械产品研发，本文对数字样机协同评审的支撑技术进行了研究，对网格环境下实时评审资源与任务管理、复杂产品海量数据模型可视化方法以及网格评审环境中协同交互模式等进行了深入探讨，并在上述研究的基础上，开发了一个灵活、可扩展的网格虚拟现实环境，较好地满足了复杂机械产品数字样机的设计及协同评审需求。本文的主要工作体现在以下几个方面：(1)针对复杂机械产品设计的特点及现有数字样机评审环境在分布式协同评审支持上的不足，基于网格计算模型，构建了一个面向数字样机协同评审的多层体系结构，并给出基于网格虚拟现实环境的协同评审方法。该体系结构的关键由私有网格支撑平台、基于服务的分布式并行渲染模块和协同评审应用服务三个部分组成。(2)从多用户实时协同评审的需求出发，通过分析网格系统中资源的异构问题，提出了适合多用户实时协同评审的资源与任务管理模型，该模型使用基于Web Services的信息索引中心保存系统的资源和任务信息，为用户任务的资源分配和启动提供任务代理服务，而在各个网格节点上由本地资源管理服务负责节点资源的注册和本地作业进程的启动和监控，形成新的专属网格支撑服务平台，这有助于提高评审的灵活性，降低异构资源共享及参与的实现难度。(3)建立了基于服务的分布式并行渲染技术框架。面向机械产品数字样机协同评审的需求，研究了复杂产品设计评审中的难点，设计了基于网格动态资源进行分布式渲染计算的实现方案，并给出了实现原型。面向大规模数据实时处理的需求，研究了大规模数据分布式协同评审中的效率瓶颈问题，提出了一种基于多线程的并行数据处理算法，提高了处理效率。(4)提出了多用户协同交互操作方案，该方案能够支持将地理分散的用户接入到一个统一的虚拟环境中，共同对虚拟产品进行装配操作评审。用户可以采用多种自然的虚拟现实交互手段，如数据手套、位置跟踪设备等，同时也支持键盘鼠标等常规交互方式。每个用户在虚拟空间中都有一个独立的映射对象，该对象代表用户在虚拟空间中的位置等属性，并可与其他用户对象进行交互。该方案提供了一致的接口规范，建立了统一的基于协同用户对象的交互和管理视图，便于各领域开发者进行评审或仿真工具的集成与开发。(5)开发了一个面向机械产品数字样机装配评审的网格虚拟现实环境VRGrid，并进行了实例的设计应用。VRGrid系统可以汇聚当前的空闲计算资源，在提高资源利用效率的同时，完成单个计算机所不能完成的大规模数据可视化任务。通过汽车整车数字样机协同评审进行了应用示范，即开发实现了多用户协同虚拟评审应用服务。该应用服务充分验证了网格虚拟现实环境及其协同评审技术可以有效地支持机械类产品的设计评审。更多还原

【Abstract】 Digital mockup review is an important part of iterated development forcomplex product. The more complex of product functionality and structure,the more refined divided in product manufacturing which come with thediffcult of digital mockup review and quality control. Grid-basedcollaborative virtual reality environment could provide solution for digitalmockup review of complex product. Virtual reality has been developed formore than ten years, and has been applied in more and more fields, and be animportant tools which could help designer and manufacture promote theircompitition ability. Grid computing, as an enabling technology toInternet-wided distributed computing, tracked the traditional parallel anddistributed computing, enable virtual reality to utilize resource over andprovide services to a wider extent of Internet.Focus on collaborative digital mockup review of complex machine, thisdissertation has studied resource and task management of simulation resourcein grid environment, huge data model visualization for complex productdigital mockup, collaborative interaction mode under grid qualification and soon. Based on above study, we implement a flexible and extensible grid-based virtual reality environment which can satisfy the design requirement ofcomplex mechanical product. Our focuses and achievements in thisdissertation were listed below:(1) According to the characteristics of complex mechanical product designand the shortage of present digital mockup review environment could notsupport collaborative review in dispersed location, a new extensiblearchitecture for collaborative review environment is proposed, and thecorresponding collaborative review method is also improved. The architectureconsists of private grid support platform module, service-based distributedparallel rendering module and collaborative review application service.(2) A new resource and task management model for multi-userscollaborative realtime review is proposed, according to the analysis ofresource asynchronous of grid system. The model uses a task proxy servicebased on Web Services index center to save system resources and taskinformation for resource allocation and tasks started in each grid node. Localresource management services are responsible for the registration, localstart-up and monitoring of the service process. The model is helpful topromote the agility of review and reduce the implementation diffculty ofreview.(3) A services-based parallel rendering framework was implemented.According to the requirement of mechanical digital mockup review, studied the bottleneck of complex product design and review, a new parallel renderingframework based on grid dynamic resource is proposed and implemented.According to the requirement of huge data process in real time, studied thebottleneck of distributed simulation with huge data, a multi-thread-basedparallel data process algorithm is proposed, and optimized the low detailprocess, improved the efficency of process.(4) A collaborative interaction scheme with multiple users is raised, whichscheme allow geographical dispersed users connect to a uniform virtualenvironment, and manipulate or review the digital mockup. The participatormay use various natual virtual reality interactive peripherals, such as digitalhands, positon tracking device, the normal interactive tools, for examplemouse and keyboard, are also supported. Each participator has acorresponding virtual object in the vitual environment, which object containthe name, position etc. of users and could interact with other user objects. Theinteraction mode has provided a consistent interface criterion and set up auniform interaction and management view based on user objects, which isconvenient for developer to integrate or design the new simulation tools.(5) A prototype system named VRGrid (Virutal Reality Grid) formechanical digital mockup review was developed; its case study is alsofinished. VRGrid could aggregate present idle compute resources to supportcollaborative review with huge data, which can excute the huge compute task which cannot be done with sinlge compute, as a result the resource usgagecould be advanced effectively. With VRGrid, we were designed andimplemented an application case: collaborative review service. The abovecase study has been used to verify the validity and effectiveness of VRGrid.更多还原