虚拟装配技术在AMT选换档机构中的应用

文中阐述了虚拟装配技术基本原理、过程、方法及其在复杂系统中的应用技术.基于三维建模软件Pro/E,以AMT选换档机构为设计对象,进行了原理分析、三维建模和虚拟装配设计.先通过对复杂系统进行结构分析,将其分解成若干功能模块,各个功能模块相互独立,可分别进行装配,若某些功能模块结构仍较复杂,可重复分解,直至得到一系列简单的子系统,最后完成总装和干涉检验,以进一步检测虚拟装配的可靠性.实践表明,利用虚拟装配技术可有效地提高设计更改的速度,缩短产品研发周期,节约成本和提高产品装配质量.     

在EMPOWER中实现雷达的虚拟装配

虚拟装配技术是虚拟制造技术在设计和制造业中的重要应用领域之一。文中阐述了虚拟装配的原理和过程,以雷达产品中的天线座系统为对象,对其装配顺序进行规划,实况装配零件和部件,实现装配过程仿真。为虚拟装配技术在雷达产品中的应用做了初步的尝试和探索。     

虚拟装配技术的应用研究

分析阐述了虚拟装配技术的原理和过程，以挤压部件为产品设计对象，进行虚拟装配设计，并进行相应的装配检验，产生装配顺序与装配路径，制作装配动画，成功地在计算机虚拟环境中完成了产品的开发设计过程。     

复杂结构产品研究进展

讨论了复杂结构产品的定义。以复杂武器系统为应用背景，以其中的关键部件飞行仪器舱为研究对象，对这类复杂结构产品的研究现状以及研究过程中存在的问题进行了分析，论述了复杂结构产品的技术趋势，从数字化技术、虚拟现实和虚拟仿真技术、虚拟装配以及协同设计技术几个方面进行了分析。     

虚拟装配技术在自动引导车转向系统中的应用

阐述了虚拟装配技术基本原理、过程和方法,提出了基于SolidWorks三维建模软件,以自动引导车转向系统为设计对象,进行三维建模和虚拟装配设计.先通过虚拟装配关系识别捕捉设计者的意图,然后利用装配约束条件确定零件的装配路径,并完成其装配,最后对自动引导车转向系统进行相应的干涉检验,并进行动画制作,进一步检测虚拟装配的可靠性.实践表明,利用虚拟装配技术可有效地缩短产品研发周期,节约成本和提高产品装配质量.     

基于虚拟零部件的零等待约束复杂产品综合调度算法

针对复杂产品实际生产中工序间存在零等待约束的综合调度问题,提出一种基于设计结构矩阵和遗传算法的综合调度算法。该算法在提出零等待虚拟零部件、非零等待虚拟零部件、叉点虚拟零部件以及子虚拟零部件等概念的基础上,设计一种更为有效的基于数字化虚拟零部件下三角设计结构矩阵的编码方式,不仅满足了复杂产品的加工装配顺序约束关系,而且体现了工序间存在的零等待约束;设计了能满足加工装配顺序约束的遗传算子,避免了不可行子代个体转化操作;提出一种满足零等待约束的解码方法,且能确保染色体经过解码后能够产生主动调度。与现有算法进行对比试验,结果表明所提出的调度算法对于存在零等待约束的复杂产品综合调度问题具有良好的求解速度和质量。     

复杂产品装配现场动态实时可视化监控系统

为了解决复杂产品装配现场动态数据实时采集和组织复杂、实时监控困难等问题,引入工作流管理和电子看板技术,构建了一个面向复杂产品装配车间现场的动态实时可视化监控系统,建立了系统的运行流程和功能结构,阐述了基于流程和日常事务的动态数据采集模型构建、动态数据实时采集、动态数据组织模型构建、基于工位布局的车间现场可视化监控等关键实现技术。该系统以装配流程和日常事务为核心,实现了复杂产品装配车间现场的动态、实时、可视化监控和精细化管理。目前所开发的系统已在航天某所正式上线运行,应用效果良好。     

柴油机虚拟装配的研究

虚拟装配是近几年来出现的先进制造技术,它是在虚拟环境中,利用虚拟现实技术将设计的柴油机整机或部件三维模型进行预装配,在满足产品性能与功能的条件下,通过分析、评价、规划、仿真等改进产品的设计和装配结构,实现产品可装配性和经济性。本文主要介绍虚拟装配研究的现状、柴油机虚拟装配系统的总体结构及柴油机虚拟装配的关键技术。柴油机虚拟装配的关键技术包括虚拟装配建模技术、虚拟装配仿真技术、虚拟装配控制技术和虚拟装配支撑技术等。     

飞机虚拟装配技术应用及发展趋势分析

随着工业的发展,大型机械装备的设计、制造,尤其航空航天、军事装备领域发展较为迅速。大型装备的设计与生产带来的问题就是产品结构复杂、装配复杂,导致设计、生产过程经常出现差错。上个世纪80年代虚拟现实的概念提出,促进了大型装备虚拟装配技术的出现并迅速发展。虚拟装配就是充分利用现代信息技术,在虚拟的环境中开展产品设计、产品制造与产品装配,在生产之前完成装配过程,提前发现问题,减小差错。本文针对虚拟装配技术总结了其研究方向和研究重点,并基于工艺为中心的虚拟装配技术开展了飞机后机身模型构建、工艺设计、虚拟装配等工作。结合飞机后机身虚拟装配技术,跟踪后机身零部件生产、实际装配工作,总结和分析了虚拟装配技术在应用方面的问题。针对问题开展了虚拟装配技术发展趋势分析。     

某型雷达T/R组件的虚拟装配应用研究

分析阐述了虚拟装配技术的原理和一般过程,结合某型雷达T/R组件的虚拟装配设计思想,提出了虚拟装配技术的设计流程,并以某型雷达T/R组件为虚拟装配设计对象,进行相应的装配检验,成功地在计算机虚拟环境（Division Mockup）下完成了某型雷达T/R组件的虚拟装配设计.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.