基于虚拟装配特征的虚拟装配研究

主要研究虚拟环境中产品的虚拟装配问题。在研究以往学者对装配特征定义的基础上 ,结合虚拟装配的特点 ,提出了虚拟装配特征的概念 ,虚拟装配特征不仅描述了产品中零件间的约束关系 ,而且描述了产品的公差。在充分考虑了公差对产品装配工艺计划和产品可装配性影响的情况下 ,提出了装配工艺计划算法。     

集成化产品装配设计与模糊评价方法研究

研究了集成化产品装配设计与模糊价方法。基于用户定义的特征,进行产品特征造型和产品装配设计,建立了产品实例库;基于产品实例进行参数化结构设计,自动生成产品的三维装配图;从ＣＡＤ系统中,对产品装配体进行了自动产品装配特征识别;基于所建立的产品装配模型自动产生品装配数据的中性文件。     

产品可装配性评价技术的研究现状和发展方向

阐述了产品可装配性评价技术产生的背景,分析了影响产品可装配性的因素,综述了近20年来国内外关于产品可装配性评价技术的发展现状,分析了现有评价技术中存在的不足。产品可装配性评价技术发展水平的相对滞后。已成为DFA一步发展和虚拟装配技术发展的瓶颈问题,因此评价技术的进一步研究,对于整个虚拟装配技术的发展有着特别重要的意义,最后提出了今后产品可装配性评价技术的研究方向。     

基于模糊神经网络产品设计的可装配性评价

首先建立了基于模糊神经网络的可装配性评价模型,然后将产品的可装配性分为零件级可装配性和装配顺序级可装配性,并将影响零件可装配性的因素分为零件装配特征的对称性、零件易于装配的形状特征个数、零件易于识别和零件易于抓取的形状特征个数,将影响装配顺序可装配性的因素分为总的操作数．非装配操作、装配工具的更换次数、平行的装配任务的数量、基础件的重定向次数和装配方向,建立了评价指标体系。最后将评价模型应用于某产品可装配性的评价。     

基于推理的有向图拓扑排序装配顺序规划及优化研究

装配顺序规划是虚拟装配中的重要研究内容。在阐述有向图拓扑排序技术原理的基础上,研究了基于推理的将有向图拓扑排序技术应用到产品装配顺序规划中的方法,探讨了应用可装配性评价技术得出最优装配顺序的途径。依据这些理论和算法在MDT平台上开发了一个箱体类产品的装配顺序自动规划系统,并以一个齿轮减速器为例进行了验证。     

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。     

基于I-DEAS平台的产品装配仿真系统的开发

对于尚处在设计阶段的产品来说,可装配性好坏最直观的效果是在计算机上仿真产品的实际装配过程。为此提出并实现了一种基于I-DEAS平台的装配仿真系统,该系统可有效地对产品的可装配性进行评价,并验证装配工艺规划结果,并在此基础上生动直观地进行产品的预装配,以检测与装配有关的问题而无需实物模型。     

Integrated knowledge-based assembly sequence planning

This paper presents a novel approach and system for the automatic generation, selection and evaluation, optimisation, and simulation of assembly plans. The information and knowledge about a product and its assembly (e.g. assembly constraints, solid model and CAD database, heuristic rules) are described using a hybrid approach and model with numeric and symbolic representation. A new methodology is presented to generate all feasible assembly sequences of the product by reasoning and decomposing the feasible subassemblies, and representing them by the assembly Petri net modelling. Qualitative strategic constraints are then used to evaluate the feasible assembly sequences. In order to obtain a good assembly sequence, some quantitative criteria such as assembly time and cost, workstation number, operator number, and part priority index are applied to select the optimal assembly sequence. Based on DFA analysis, MTM time analysis, and assemblability analysis, estimates are made of the assembly time and cost of the product when each of these sequences is used. A knowledge-based system KAPSS has been developed to achieve the integration of generation, selection evaluation, and visualisation of the assembly sequences.     

集成化面向装配的设计研究

提出用多重装配连接图表示产品中零件之间的多重装配关系,用模糊连接图中的结点和连接边的模糊度来模糊评价产品可装配性。对产品装配体,进行自动装配特征识别,基于所建立的产品装配模型自动产生产品装配数据的中性文件。建立了产品可装配性评价体系;基于产品装配数据和装配知识,对产品可装配性进行模糊定量评价,从而指导产品装配设计,实现了CAD/DFA的信息集成。     

基于CATIA中DELMIA的虚拟装配技术的应用

以某产品的模具为例,对虚拟装配技术在模具产品上的运用进行了初步的探讨,从虚拟装配的实现流程、产品的层次结构划分、装配顺序规划及路径规划进行了分析,并基于CATIA实现了该产品组件的装配过程仿真,确定了合理的装配顺序和路径,为虚拟装配技术在产品上的深入应用提供了有益的探索。结合装配工艺的特点和要求,提出了基于虚拟装配技术进行装配工艺设计的流程;最后针对装配工艺设计的实现方法和软件系统做了概述。     

基于Pro/E3.0的三环减速器的虚拟装配及运动仿真

主要利用Pro/ENGINEER WildFire3.0对三环减速器进行三维实体建模、虚拟装配及运动学仿真.采用参数化设计理念,给出了一种变位渐开线直齿圆柱齿轮和内齿轮板的精确画法.通过Pro/E3.0的虚拟装配及运动仿真技术,优化了产品设计,缩短了新产品的开发周期,提高了产品的可靠性.     

基于方向变换矩阵的三维装配草图生成方法

针对求解方案设计获得的可行方案的空间布局及可视化表达问题，提出了三维装配草图的一种自上而下设计方法，建立了方向变换矩阵，并通过其分解描述子装配体在空间的布局。基于三维实体造型平台，提出了相应的算法加以实现。通过一个设计实例验证该生成方法及算法可行、有效。     

虚拟装配技术在雷达装配中的应用

虚拟装配技术是虚拟制造领域的核心技术之一。重点介绍了虚拟装配核心技术及虚拟装配环境构建,并在此基础上以雷达某部件为例,在eM-Engineer软件虚拟环境下,对其装配过程进行演示,以可视化方式实现了对其可装配性的研究。     

支持设计和工艺过程的装配模型

产品装配建模是对产品进行设计评价的基础,ＳＴＥＰ是支持产品整个生命周期的产品信息数据交换标准;本文提出了反映设计过程和装配过程的二叉树装配模型。采用面向对象的技术,用ＳＴＥＰ的ＥＸＰＲＥＳＳ－Ｇ 对装配单元进行描述,便于产品的可装配性评价及与其它应用领域如ＣＡＤ、ＣＡＭ 等的集成。     

Application of Virtual Assembly Tools for Improving Product Design

Virtual product creation and product design analysis are essential for studies in the investigation into assembly feasibility and help reveal practical manufacturing constraints. This paper demonstrates an application of a virtual assembly tool DYNAMO for a grill plate assembly. Virtual simulation and assembly verification is illustrated. Both virtual simulation and assembly verification enable designers to identify potential assembly difficulties encountered in manufacturing and thus save time and cost in real production. The paper also examines factors that influence the efficiency of assembly, namely, assembly method, assembly sequence, and assembly time. Suggestions for redesign for assembly improvement provided by some design for assembly methods are also discussed.     

虚拟装配工艺设计技术研究与应用

阐述虚拟装配工艺设计技术内涵及其体系结构,深入分析其所涉及的CAD系统与虚拟现实系统间的数据转换、碰撞检测技术、装配规划与仿真以及装配运动导航与准确定位等关键技术,并应用该技术,以商品化CAD系统Pro/E为建模工具,在VC与WTK平台及ORACLE数据库的支持下开发了一个虚拟装配工艺设计原型系统HIT-VAPD,实现了虚拟现实环境下的产品装配工艺规划与设计.实际应用表明,该系统可显著提高装配工艺设计效率,减少设计缺陷.     

Concurrent tolerance design for manufacture and assembly with a game theoretic approach

This paper proposes a game theoretic approach for concurrent tolerance design considering the practical manufacturing process and assembly process, to achieve lower manufacturing cost and good product assemblability. The optimization objectives and constraints for concurrent tolerance design for manufacture and assembly are discussed, and the key technologies for concurrent tolerance design with game theory are investigated, including the strategy set division, payoff calculation, and Nash equilibrium evolution. An optimization algorithm is proposed to achieve concurrent tolerance design with a game theoretic approach, and the genetic algorithm is used to conclude the Nash equilibrium of the game for manufacture and assembly. Finally, a case study is given to verify the proposed approach.     

Efficient method of assembly sequence planning based on GAAA and optimizing by assembly path feedback for complex product

In the process of complex product assembly, assembly resources (fixtures, tools, operations, and so on) must enter assembly environment with parts together to rapidly finish product assembly. Assembly planning must take assembly resources into account fully. But, designer cannot plan every assembly procedure because of the lack of assembly resources during assembly design. Then, it will cause assembly failures and redesign for assembly easily. This paper investigates an efficient method of assembly sequence planning based on genetic algorithm and ants algorithm (GAAA) and optimizing by assembly path feedback to assembly process planning including assembly resources for complex products. Firstly, a new GAAA is investigated to rapidly plan assembly sequence in order to solve the nondeterministic polynomial-bounded problem in high searching and solving efficiency. Secondly, on the basis of the assembly sequence, a B-Rep filling algorithm which can form a swept volume between the part and its kinetic orientation is developed to plan assembly path interactively. Thirdly, the performance of the assembly path according to the assembly sequence is analyzed and sent back to avoid the most of assembly collisions and interventions during product assembly design. Lastly, we develop a simulating system to simulate assembly sequence and path based on component application architecture for CATIA V5. The simulating result proved that the proposed method of assembly sequence planning based on GAAA and optimizing by assembly path feedback for complex products is efficient. Assembly optimal design including assembly resources can work well.     

基于功能分析的定量面向装配的设计方法研究

提出一种新的基于功能分析的定量面向装配的设计方法．并且给出分析产品可装配性的模糊评价模型和相关的实验数据．分析结果证明了方法的可靠性和有效性。     

装配虚拟边界及其仿真研究

针对装配件与装配夹具之间的定位特征在实际装配过程中存在浮动错位,且不能用装配件特征的最大实体实效边界来判断装配件的可装配性问题,提出了装配虚拟边界(Assembly Virtual Boundary,ASVB)概念,研究采用VisVSA公差分析软件对装配虚拟边界进行了模拟仿真和分析,所提出的方法可为浮动错位情形下的公差设计分析提供参考。