百吨级汽车起重机分动器的开发

介绍了国外起重机分动器的产品情况,并结合汽车起重机的整车特点分析了汽车起重机分动器的设计技术难点,从分动器的主要技术参数确定、整体方案设计和高强度齿轮传动、强制润滑和散热系统、全时驱动差速器、前输出结构及壳体设等方面介绍了百吨级汽车起重机分动器的设计,通过对分动器进行台架和装车试用,验证了分动器总成的开发效果。     

梯形图设计软件的重构技术

为解决梯形图（LD）设计过程中大量复用片段引起的设计繁琐等问题,提出了将重构技术应用于梯形图设计软件中的相关理论研究和实现。该理论包含梯形图构件模型和构件重构模型,着重探讨了构件组装方式和构件间结构关系,最终实现了梯形图程序设计的动态可重构。实验结果表明,该设计软件可有效地提高梯形图设计效率,优化内存利用率,并且具有广泛的通用性和适应性。     

定制产品需求知识重构及粗糙集分析方法

对定制产品需求知识进行多粒度分解与重构建模,然后将粗糙集理论引入需求知识处理分析过程,提出基于粗糙集理论的需求知识分析与约简方法,对需求知识的重要度进行权衡评价,从而指导产品的定制设计过程。结合项目实施,将以上方法在空分装备产品的需求知识构建与分析中进行应用,证明了所提方法的适应性和有效性。     

大型复杂零件反求软件开发及功能实现

在大尺寸复杂零件反求设计实际应用过程中,往往需要正向设计软件能够直接处理点云数据而逆向设计软件能够直接进行参数化实体造型。针对这一实际工程需要,对点云数据获取与预处理、多视测量与数据拼接、复杂曲面特征提取与重构等理论和方法进行研究,以VC++6.0为开发工具,借助UG/OPENAPI平台开发了RETOOL反求系统;该系统可内嵌于UG NX系统,实现了正向设计软件能够直接处理点云数据的功能;以风机叶片等零件为应用实例详细阐述了RETOOL系统用户界面、点云数据获取、特征点提取和特征曲线拟合等模块开发过程。     

基于生长型设计的产品反求

当前的反求工程研究大多集中于三维重构和快速成型方面,而针对产品的反求设计理论与系统研究较少.文中引入了产品功能结构分解重构原理与广义定位原理的生长型设计理论,在此基础上开发了支持后续创新设计的产品反求系统.从已有产品的实体模型出发,应用生长型设计理论对产品设计过程进行回溯,将产品分解为由功能元组成的功能原型,然后通过功能元之间的耦合作用实现对需求原型的反求,支持基于产品功能结构进行的产品结构方案的创新设计.     

基于3D打印的手压充电筒设计与开发

随着先进制造业不断发展,3D打印技术作为一种新兴的制造方式,可推动工业产品设计与应用。基于3D打印的手压充电筒的设计与开发,通过手绘设计出产品的外观及结构设计,基于3D打印技术、模型三维数据扫描、三维造型软件曲面重构与质量分析相结合,快速成型出产品,再将样品进行试装配,便于设计师达到客户需求,从而大大减少产品设计到成型的周期,节省产品研发成本的目的。     

板件拼装焊接线可重构监控软件设计

以板件拼装焊接线监控软件为研究对象,对监控软件的可重构进行设计。通过对板件拼装焊接线控制系统重构过程进行分析,并结合一般监控软件的功能与特点,对板件拼装焊接线监控软件的关键需求进行分析,然后以监控软件的可重构配置性、可重用性、实时监控以及操作便捷性为设计目的,从软件的通信设计、数据可配置以及配置操作界面等角度对焊接线监控软件进行设计,提出了基于"组冗余与项选择"的数据配置策略,实现了对监控软件的数据配置。板件拼装焊接线监控软件可满足当焊接线系统发生重构时,能够通过监控软件操作界面的简单配置而无需重新编译就可实现监控软件的快速重构,从而对重构后的焊接线系统进行监控。     

大功率分动器润滑散热系统的设计与试验研究

大功率分动器作为某多轴超重型底盘传动系统的关键部件,具有传递转矩大、转速高、环境温差大等特点,单纯依靠飞溅润滑和自然风冷散热已无法满足多轴超重型底盘高机动性、高越野性和极限环境温度的使用需求,需采用强制润滑系统对分动器内部各产热点尤其是轴承位置进行润滑。因此,首先建立了传动部件各产热点的功率热能模型,通过热平衡条件估计各润滑点和总体的流量需求,然后建立液压仿真分析模型,设计匹配润滑系统管路;同时,针对动力传动系统功率大,自然风冷散热无法满足分动器热平衡要求的问题,通过计算分动器的表面风速、散热表面积评估分动器箱体自身的散热能力,并根据散热量需求匹配外置的风冷散热器和风扇。最后,通过台架和跑车试验,验证了所设计的大功率分动器强制润滑散热系统能够满足某多轴超重型底盘的各项使用要求。     

面向可适应性的稳健性产品平台规划方法

为更好地快速响应市场的多样化需求,引入面向可适应性的产品平台结构概念。根据稳健设计与可适应设计在提升产品适应外部环境变化的能力、考虑设计变更及以低成本获得高质量产品方面的一致性,提出了面向可适应性的稳健性产品平台规划方法,在产品平台规划初期就开始考虑产品的稳健性,并使设计具有可适应性,以避免后期出现大的返工。以公理设计理论为指导,通过“Zigzagging”映射,依照功能需求分析及三种类型的划分,合理提炼特征设计参数,建立产品平台的功能要求和设计参数矩阵。将灰色系统理论应用到产品平台的稳健设计中,结合试验设计与关联度方差分析,合理识别平台参数和变型参数。然后分两阶段进行稳健优化,确定产品族基体产品和每个变型产品的设计参数的最佳设计方案。通过卷筒组产品族的规划实例,说明了该方法的可行性和实用性。     

基于信息公理的产品平台可适应性评价方法

基于产品平台的产品族规划是实现大规模定制规模经济和范围经济性的有效途径,是产品创新和快速满足用户多样化需求的有效方法。具有可适应性的产品平台,可为产品族的变型、演化与升级提供支撑。分析了可适应产品平台的规划策略、结构组成和内部关系,要求产品平台应具有适应客户需求变化的能力。从平台的重用性、定制性、接口柔性和升级能力四个方面考虑,以公理设计理论中的信息量作为测度衡量平台适应客户需求更改的能力,提出了平台设计可适应性的计算方法。最后以轨道式集装箱门式起重机平台的可适应性评价为例,验证了该方法的可行性和实用性。     

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.     

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....     

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。     

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.