面向集成数据模型的逆向工程系统研究

在集成逆向工程系统研究现状的基础上,建立由数字化子系统、模型重构子系统和产品制造子系统三部分组成的面向集成数据模型的逆向工程系统框架结构.对系统实现的关键技术及系统集成的数据转换技术进行研究,并重点介绍实现远程逆向工程技术的方法.通过应用实例验证该集成系统可有效地缩短产品制造周期、降低产品设计及开发成本.     

逆向工程技术及其应用研究

首先介绍了逆向工程的含义及其工作流程,阐述了三维点数据采集的过程及原理,讨论了利用逆向工程软件Geomagic对排气歧管点云数据进行处理,介绍了曲面的创建及造型过程.最后根据用户要求,利用逆向工程技术,实现了对排气歧管复杂曲面的逆向设计与曲面重构.实践表明,利用逆向工程技术可以显著提高产品的设计效率.     

逆向工程技术的研究现状及发展趋势

随着测量技术和计算机技术的发展，以实体为研究对象，利用逆向工程技术对产品进行建模、仿真、优化及新产品开发成为现代设计的一大热点。本文阐述了逆向工程的基本概念、产品几何形状的数字化技术、测量数据的预处理技术、模型重建等，并对逆向工程的未来趋势进行了展望。     

支持产品生命周期的远程服务系统研究与开发

分析了现有的产品生命周期管理理论,详细论述了产品全生命周期服务理论以及通过远程服务方式实现产品生命周期服务的思想。根据产品全生命周期服务的需要,系统地研究和分析了远程服务的组织模式,如一对一、一对多、服务联盟以及第三方服务模式等。在对远程服务理论研究的基础上,进一步研究了实现远程服务所需的一些关键支持技术,提出了基于J2EE应用服务器和中间件开发技术且支持过程集成的远程服务集成平台体系结构,并针对这些研究成果,给出了已实现的远程服务系统。     

基于Web的快速模具远程制造服务系统

数字化和网络化已成为当前制造业最为显著的生产特征。为了改变快速模具的传统制造模式为基于Internet的异地协同开发制造模式,解决逆向工程(RE)、快速成形(RP)、快速模具(RT)设备低利用率与企业得不到快速成形与制造(RP&M)技术服务的矛盾,缩短模具的生产制造周期,迎合新产品快速开发的需求。研究和开发了基于Web的快速模具远程制造服务系统。首先介绍了基于RE/计算机辅助设计(CAD)/RP快速模具开发制造系统的工作流程及其组成;然后阐述了远程制造服务系统的功能设计和关键技术的实现;最后构建了服务系统运行的Web平台。该系统旨在集成已有的RE、CAD、计算机辅助分析(CAE)、RP技术及以此为基础的快速模具制造技术,并以万维网(WWW)为支撑,以RP&M服务中心和各生产力促进中心为服务载体,以为远程用户、服务中心、协同制造企业提供方便快捷的技术信息平台、电子商务平台、制造服务平台为服务宗旨。     

基于云计算的产品远程定制系统的设计

本文针对产品远程定制的特点,建立基于云计算平台的云+端四层体系结构。通过分析产品定制设计和仿真的需求,设计出产品定制应用的设计与仿真服务,采用Eucalyptus云计算平台、Euca2ool、Portal以及Portlet技术等来实现系统,使用户可以获取更高的计算能力、存储空间及软件服务,从而实现个性化的产品远程定制。     

快速逆向工程的研究

为适应时代对产品少量多样化的需求，运用测绘技术，快速将目标实物的三维外形数字化，将实物原型迅速地转变为CAD模型是快速逆向工程面临的关键技术。综合国内外快速逆向工程技术的研究和应用现状，从快速测量和快速建模相结合的角度出发，分析了快速逆向工程几何测量的特点和需要进一步解决的主要问题，最后对逆向工程的研究重点提出建议。     

逆向工程技术研究进展

逆向工程是指从实物样件获取产品数学模型、进而开发出同类的先进产品的技术，目前逆向工程技术CAD/CAM等先进制造技术结合，并发展为CAD/CAM系统中一个相对独立的研究领域，其关键技术问题主要包括：形状表面数字化、3维模型重建、集成逆向工程系统等，文章回顾了国内外的研究现状及商业软件开发情况，对目前逆向工程研究与应用存在的问题及解决的对策提出了讨论。     

塑料模具制品快速创新再设计与逆向工程

阐述了逆向工程的关键技术,提出逆向工程是实现模具制品快速再设计的重要途径;同时指出逆向工程也绝非仅仅是对已有产品的简单复制,产品设计的快速性和局部创新性才是其可持续发展的灵魂.进而给出了基于逆向工程产品局部创新设计需要考虑产品的可成型性、实用性能以及尊重知识劳动等因素,最后讨论了面向局部创新设计逆向工程的技术关键点.     

TCESS的建立和与PDM系统集成的研究

制造企业的竞争体现在T、Q、C、S、E五要素，随着市场的发展，各个企业产品的质量和成本的差异缩小到一定程度后，服务开始成为客户选择产品的重要因素。文章讨论了以客户服务为中心的远程客户工程支持系统TCESS的基本组成和基本功能，分析了它和企业PDM系统的关系，并且结合同济大学CIMS研究中心的远程服务示范系统的开发，给出了远程客户支持系统的实现方案以及PDM系统SmarTeam的集成方法。     

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...     

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.     

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.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.