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虚拟装配是虚拟现实技术在产品设计领域的一个重要应用 .为了从运动学与动力学的角度来考察虚拟装配过程中零件的运动 ,以便更真实地反映虚拟环境中零件装配运动的本质规律 ,提出了一种虚拟装配环境中用于将装配几何约束自动映射为运动副约束的基于运动自由度分析的物理约束生成方法 ,同时 ,提出了基于变刚度弹簧模型的装配力交互输入方法 ,并实现了位移输入与装配力输入的映射 .另外 ,还给出了基于物理模型的虚拟装配的基本过程 .该方法在虚拟设计与装配原型系统的研究与开发中已得到实现 . 相似文献
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Assembly modelling is the process of capturing entities and activity information related to assembling and assembly. Currently, most CAD systems have been developed to ease the design of individual components, but are limited in their support for assembly designs and planning capability, which are crucial for reducing the cost and processing time in complex design, constraint analysis and assembly task planning. This paper presents a framework of a two-handed virtual assembly (VA) planner for assembly tasks, which coordinates two hands jointly for feature-based manipulation, assembly analysis and constraint-based task planning. Feature-based manipulation highlights the important assembling features (e.g. dynamic reference frames, moving arrow, mating features) to guide users for the ease of assembly and in an efficient and fluid manner. The users can freely navigate and move the mating pair along the collision-free path. The free motion of two-handed input in assembly is further restricted to the allowable motion guided by the constraints recognised on-line. The allowable motion in assembly is planned by the logic steps derived from the analysis of constraints and their translation in the progress of assembly. No preprocessing or predefined assembly sequence is necessary since the planning is produced in real-time upon the two-handed interactions. Mating features and constraints in databases are automatically updated after each assembly to simplify the planning process. The two-handed task planner has been developed and experimented for several assembly examples including a drill (12-parts) and a robot (17-parts). The system can be generally applied for the interactive task planning of assembly-type applications. 相似文献
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传统的力触觉渲染多采用阻抗控制,不能很好地满足虚拟装配的应用要求,相比之下导纳控制模式更适用这一领域.为此提出一种基于导纳控制的双线程力觉渲染构架,并给出相应的力觉渲染算法.首先建立用于导纳控制的动力学模型,并讨论了碰撞和约束这2个状态下的力觉渲染;为了使用力觉交互接口进行虚拟装配中的小间隙装配,提出物理约束与几何约束结合的力觉渲染方法;最后针对物理计算和力反馈循环2个线程刷新频率不匹配的问题,利用二次拉格朗日多项式进行数值插值,实现了力觉交互接口的平稳输出.通过力反馈设备与自主开发的虚拟装配原型系统VAPP的连接与应用,验证了所提出的算法满足虚拟装配系统中力觉交互的应用要求. 相似文献
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随着虚拟现实技术的逐渐成熟,研究者们已将其引入到工程领域,为实现虚拟设计与虚拟装配过程的集成,避免现有的虚拟装配系统中,虚拟环境与CAD系统间所必需进行的复杂的、无谓的数据传输,描述了一个基于多通道的、集成的虚拟设计与虚拟装配系统VDVAS。在该系统中,设计得可以通过直接三维操作和语音命令直观方便地建立机械零件及其装配模型,并通过交互拆装来得到零件的装配顺序和装配路径等信息,VDVAS的一个重要特征在于,可通过集成虚拟设计与虚拟装配过程,使设计者能在一个集成的虚拟环境中修改零件几何(假如在装配过程中发现零件存在设计缺陷的话)。 相似文献
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Virtual assembly has been widely used in product development. However, virtual operation and actual operation are different in time and space, the simulation of interactive virtual assembly cannot support the assembly operation's process planning directly. In this paper, the solution for assembly operation's process planning is developed based on interactive virtual assembly. According to the solution, interactive assembly operation is used to obtain the actions of operation sequence. The actions are mapped into the data of a real operation action to obtain real operation actions. Then assembly operation cards can be obtained. To support the assembly operation actions obtained through virtual assembly simulation, a product assembly model is proposed. An operation semantic model is used to replace the geometric constraint model of assembly, which contains several ordered geometric constraints and some engineering restriction conditions. To test the solution and the models, one process planning example of an automobile engine is introduced. The results verified the feasibility and the effectiveness of the methods. 相似文献
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面向虚拟环境的装配体模型研究 总被引:8,自引:1,他引:7
人机交互是虚拟装配的本质特性和技术瓶颈,能反映交互过程的装配体模型构造,是虚拟装配领域的一个关键问题,给出一种时序的装配体模型,对时序的聚合关系、时序的约束关系以及时序的行为结构给出定义和分析,为实现该模型,还给出了零件的中间模型和对象复杂行为构造,同时对虚拟装配直接操作的交互过程、交互模式及装配工艺知识给出了时序的形式描述,这是连接人机交互与装配体模型以及模型与工艺生成的桥梁.一致的表示模型减少了交互装配信息的冗余性,有利于提高交互信息的复用,为交互生成工艺提出了新方法。 相似文献
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计算机辅助装配系统设计是计算机应用于制造业的重要技术之一,在实际工作中具有非常重要的意义.本文通过对装配工艺的分析,提出一种基于网络化的虚拟装配的方法. 相似文献
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虚拟环境中面向装配设计的数据场景图研究 总被引:4,自引:2,他引:4
作为虚拟环境中的数据结构,场景图的构建是虚拟现实技术领域的重要研究问题之一。针对虚拟装配设计系统的要求,讨论现有商业VR软件在开发虚拟装配设计时存在的限制,提出一个基于场景图的多层次虚拟装配设计模型VAM.在现有VR软件和VAM的基础上,说明了虚拟装配设计时的路径规划、序列生成、零件之间的约束关系等的表示和应用。 相似文献
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针对装配的动态过程显著地表现出连续与离散共存的混杂特性,研究了面向虚拟装配的混杂系统建模以及控制器设计方法.提出了混杂基本结构对应于单个装配对象的建模方法,有效地避免了由于装配零部件过多给模型造成的复杂性,并在此基础上,运用最小干预安全控制器对装配过程中的不合法结构实施控制,最后以某汽车底盘总装中两个装配对象为例,给出了具体的动态描述及其建模和控制器设计。证明了该方法的可行性和有效性. 相似文献
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Markus Schlattmann Ferenc Kahlesz Ralf Sarlette Reinhard Klein † 《Computer Graphics Forum》2007,26(3):467-476
In this paper we present a novel computer vision based hand-tracking technique, which is capable of robustly tracking 6+4DOF of the human hand in real-time (at least 25 frames per second) with the help of 3 (or more) off-the-shelf consumer cameras. ‘6+4DOF’ means that the system can track the global pose (6 continuous parameters for translation and rotation) of 4 different gestures. A key feature of our system is its fully automatic real-time initialization procedure, which, along with a sound tracking-lost detector, makes the system fit for real-world applications. Because of this, our method acts as an enabling technology for uncumbersome hand-based 3D Human-Computer-Interaction (HCI). Previously, using the hand as an at least 6DOF input device involved the use of either datagloves or markers. Using our tracking we evaluated the use of the hand as an input device for two prevalent Virtual Reality applications: fly-through exploration of a virtual world and a simple digital assembly simulation. 相似文献
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航空发动机教学实验系统的虚拟装配技术研究 总被引:1,自引:0,他引:1
航空发动机虚拟教学实验系统的建设是将VR(Virtual Reality)技术与实验相结合的一次综合性的实验探索与尝试.该系统是将虚拟装配及拆卸、模化实验、模型流场的动态显示及发动机试车等综合仿真实验系统,重点论述了教学实验系统开发中的虚拟装配技术,在对虚拟装配的研究现状分析和总结的基础上,对航空发动机虚拟装配的关键技术和虚拟装配系统的实现方法进行了分析和研究,包括基于数据手套的虚拟手操作、实时碰撞检测、装配路径和装配顺序规划等问题.最后还展示了利用航空发动机三维可视化虚拟装配系统完成虚拟装配操作的实例,并分析了虚拟装配系统与传统装配相比较的优势和特点. 相似文献
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虚拟装配仿真系统相关技术的研究 总被引:1,自引:0,他引:1
研究了一种等离子体增强化学气相沉积(PECVD)装备虚拟装配仿真系统,介绍了系统的装配模型以及装配顺序和路径的规划.建立了虚拟装配仿真场景结构图,并采用细节层次技术对仿真场景进行优化.为了能够实时、方便地修改装配序列和装配路径,准确地描述零部件在装配或拆卸过程中的位置姿态信息,提出了一种虚拟装配的描述语言代码(V代码)和虚拟装配函数(V函数).最后采用基于包围盒逐层分解的干涉检验方法,实现装配过程的干涉检验.该仿真系统有助于缩短产品开发周期、提高设计质量、降低装配成本. 相似文献
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并行工程角度出发的机械虚拟原型是集成了产品的设计、分析,不断迭代、优化的过程,模型的协调一致性是保证设计过程完整的关键,如产品模型在CAD模型与机械多体动力学模型中的一致性表达。在这种观点下,该文提出在建立基于组件的机械系统虚拟原型时,从CAD中抽取多体动力学模型构件的物理属性,研究了国产三维实体设计软件CAXA环境下,基于多刚体系统动力学笛卡尔方法,从CAD模型映射多刚体动力学分析模型语义的实现方案。分析了多刚体系统动力学模型语义下,多体动力学约束模型坐标基变换关系的抽取。实验结果表明,从CAD中抽取多体动力学模型的物理属性的方案是可行的。可以用于建立基于组件的多体系统虚拟原型的分析模型,实现自主开发设计、分析集成的机械虚拟原型。 相似文献
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Interactive modeling and simulation of virtual manufacturing assemblies: An agent-based approach* 总被引:3,自引:0,他引:3
In this paper, an agent-based design and development of an interactive virtual environment for a manufacturing assembly process is described. Agents in the assembly are identified through their respective responsibilities and are implemented so that they coordinate between one another to accomplish the PC assembly/disassembly process. The robot agent, crucial to the assembly operation, is designed to handle multiple failure situations, wherein it coordinates with the part agent to accommodate the failure. 相似文献