高铁车厢柔性预装配平台设计研究

针对高铁车厢预装配不可重用、柔性差及自动化程度低等问题,对高铁柔性预装配进行了研究,提出了由内外龙门及相应的机械手组成的预装配平台,内龙门机械手通过外龙门机械手提供动力实现了位置移动及装配点的定位。通过开发基于台达触摸屏和PLC分布式控制系统,实现了PLC控制程序和人机界面软件相结合的柔性预装配控制。通过上位机软件的规划及管理最终实现了预装配过程的自动化及智能化。现场试验结果表明,该系统实现了真实模拟车厢装配环境、准确定位车厢内关键零部件的位置,根据车厢情况灵活配置实现了柔性装配等多项功能,具有一定的实用性及推广价值。     

基于车厢轮廓离散法的高铁自动化柔性预装配技术研究

高铁车厢的预装配试验是高铁制造工艺链中的一个重要环节,现有的试验方法存在着生产成本高、重复利用率低的问题。基于对车厢结构特征及装配需求的分析,提出一种高铁车厢轮廓的离散表示方法,并研制了一套成本低、自动化程度高、驱动机构与执行机构分离的柔性预装配实验系统。样机试验表明,该系统可大幅降低高铁车厢预装配实验成本,提高预装配的精度及效率。     

适应自动钻铆的壁板预装配柔性定位装置设计

飞机壁板在预装配完成后,自动钻铆时需利用托板对其重新定位,降低了装配效率。结合飞机壁板的结构特点和自动钻铆工艺等,设计了一套能够适应自动钻铆的壁板预装配柔性定位装置,并利用遗传算法对其结构进行了优化。该装置可实现对多块飞机机身壁板的柔性预装配,并可与自动钻铆机良好的结合,避免了飞机壁板在自动钻铆机托架上的二次定位,提高了装配效率。     

分布环境下面向过程的协同预装配活动模型研究

为支持和规范分布环境下不同团队间面向过程的协同预装配活动，提出了支持面向过程的协同预装配活动模型，定义并分析了模型的组成；对模型中的协同装配操作并发控制方法和协同装配场景同步维护过程两个关键部分进行了详细的讨论和分析。利用模型建立了支持多主体的协同装配系统，通过示例说明和验证了模型的应用。     

基于Web的协同装配系统及其关键技术研究

利用网络资源，实施跨平台、跨地域的产品零部件预装配，快速验证产品的可装配性，协同进行了产品装配工艺规划，是当今面向装配设计的研究热点之一，按照Web体系的标准三层模式，以Internet使能数据格式虚拟现实造型语言作为产品模型的载体，基于Cortona API，采用VC＋＋编程，实现了协同装配系统框架，讨论了面向协同广义装配建模概念，装配子任务编码方法，装配人员评价指数确定原则，以及协同装配协议等关键技术，最后给出了一个应用实例。     

机器视觉在柔性制造生产线分拣机械手中的应用研究

为了解决柔性制造生产线机械手的智能化分拣问题,以并联机械手、工业相机和BS-8ML01型柔性生产线为基础,设计了一个基于机器视觉的分拣系统。该系统工业相机直接集成于机械手的定平台,以实现对传送带送来的工件进行图像采集及软件图像预处理。研究中对传统的Hough算法进行了改进,采用基于有序Hough变换的算法进行工件边缘的提取和定位,并以此对机械手的运动轨迹进行规划,采用Matlab对机械手的末端动平台进行动力学分析。最后样机实验表明,该基于机器视觉的分拣机械手算法稳定可靠,可广泛应用于一般小尺寸工件的分拣工作,提高了柔性制造生产线的自动化、智能化水平。     

基于实测数据的天线座数字化装配仿真技术

文中对现阶段车载情报类天线座的装配流程进行梳理,提炼各零部件的关键建模特征和装配特征,筛选识别关键装配参数,构建天线座数字化装配孪生虚体。通过导入关键零部件的实测数据,以满足传动装配质量为约束,快速生成天线座实际装配仿真模型。基于Creo2.0开发天线座数字化装配仿真软件,开展装配过程仿真,提前识别装配干涉,形成垫片修配环节作业指导并向装配现场发布,消除实物预装风险,实现由实物预装向虚拟预装模式的转变。最终以某型号车载雷达天线座为应用对象,完成天线座装配仿真技术的应用验证。     

面向多品种小批量产品的柔性装配系统研究

针对制造企业多品种小批量产品生产对敏捷性的要求,提出了一种柔性装配系统的设计方法,该柔性装配系统能够根据装配现场实时信息动态调整任务并通过控制系统控制现场实施。结合某企业实际情况实现了柔性装配过程的动态管理;利用Plant Simulation对该柔性装配系统进行了仿真研究,验证了该方案的可行性和有效性,为多品种小批量产品柔性装配的研究提供了有价值的参考。     

具有柔性浮动手爪和并联腕的装配机械手设计

机器人化装配是机器人研究与应用的一个热点。采用机器人进行自动化装配可以提高产品的生产效率和装配质量。而异形薄壁零件的自动化装配存在两大困难。即柔性抓取和姿态调整。装配机械手以吸盘作手爪可以实现柔性抓取，采用浮动结构可以实现准确定位，以并联机构作手腕可以实现调姿要求。本文介绍了柔性浮动手爪和并联手腕的设计思想和关键技术。     

面向直升机研发的数字化预装配技术的算法及应用研究

数字化预装配技术是当前计算机辅助技术中的热点问题。数字化设计制造技术在飞机设计制造中的应用,使得飞机设计制造技术体系、设计方法、设计理念、管理方法发生了根本性的变化。为了使数字化预装配技术在航空工业的直升机设计制造过程中发挥更好的作用,本文结合某型号直升机研发中DPA技术的应用,研究和探讨了DPA技术的关键算法:干涉检查算法以及装配/拆卸算法。     

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.     

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....     

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。     

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.