基于虚拟仪器的新型粗糙度测量系统的开发

利用轮廓仪与LabVIEW可视化的虚拟仪器系统开发平台相结合,本文开发了新的表面粗糙度测量系统。表面粗糙度评定参数的数学定义与功能模块程序相关分析,虚拟仪器的软件开发,实现了粗糙度多参数测量与评定。     

表面粗糙度的测量分析

表面粗糙度的测量方法很多,在具体的测量过程中要根据实际需要来选择不同的方法以满足不同的需求,本文着重介绍表面粗糙度参数选择、测量的方法以及在测量过程中的注意事项.     

石墨加工表面粗糙度图像评定方法

针对接触式测量脆性石墨材料表面粗糙度时存在探针和工件易损伤等问题,提出基于MATLAB进行表面粗糙度测量数据采集和处理的一种新方法。应用GUI(Graphical User Interface)图形界面回调函数(Callback)编写控件,设计易于用户交互的可脱离MATLAB环境独立运行图形界面粗糙度计算软件。通过MATLAB编写的程序对工件的表面形貌图像进行数字化预处理(灰度化,降噪,滤波等),进行轮廓边缘提取、轮廓边缘曲线数字化和最小二乘法拟合等计算,最终计算出图像灰度对应表面粗糙度,实现表面粗糙度计算和输出,通过试验验证了图像评定机械加工表面粗糙度系统准确性。     

在AutoCADR12／R13平台上实现表面粗糙度标注

论述用ＡＤＳ编写表面粗造度标注程序的方法。本程序是根据表面粗糙度的最新国家标准（ＧＢ３５０５８３，ＧＢ１０３１８３）的要求编制该程序的。为满足不同用户的需要，采用图形界面和指令并存的编程方式。     

光学干涉法在航天阀门产品表面粗糙度测量中的应用

航天阀门产品如活门壳体、阀芯等,其密封面处表面粗糙度的加工精度,对阀门密封性能起着至关重要的作用。采用垂直扫描光学干涉法,根据产品材质和表面形状等特性设置不同的测量参数,获得活门壳体平面形密封面、R形密封面和非金属阀芯密封面表面粗糙度的测量图像及测量结果。经测量不确定度分析,扩展相对不确定度小于10%,满足测量精度的要求,实现了毫米级小尺寸平面和曲面表面粗糙度的高精度非接触测量。     

虚拟仪器技术在粗糙度测量中的应用

传统的轮廓仪与虚拟仪器技术相结合 ,构建新的粗糙度测量系统 ,实现表面粗糙度多参数测量与评定。     

电容法测量表面粗糙度

在表面粗糙度的测量上,触针法是主要的检测方法,近年来光学法又有了很大发展,但它们各有特点,不能完全满足检测需要,我们根据平行板电容器的原理,用电容法测量表面粗糙度的四个参数,由实验中证实丁电容法测量粗糙度的可行性。电容法属于三维测量,仪器结构简单,操作方便,可以实现非接触测量。可用于加工中检验和大批量生产的车间。 一、电容法测量的基本原理     

表面粗糙度参数的计算机评定

介绍了最新国家标准中表面粗糙度的评定参数,通过程序实现了多项粗糙度参数的计算,并用实例说明了程序的有效性。     

三维表面粗糙度的表征和应用

表面粗糙度会直接影响零部件的耐磨性、密封性以及抗腐蚀性等,是评定机械加工和产品质量的重要指标。现代科技水平的不断提高对零件表面性能的要求也日益严苛。传统的二维表面粗糙度的测量和表征已经不再能够满足技术发展的要求,三维表面粗糙度由于能够更加全面、真实地反映工件表面的状态而受到人们的重视,成为研究热点。本文回顾了三维表面粗糙度的发展历史,系统地介绍了三维表面粗糙度参数及标准的发展现状,分析了表面形貌与功能特性的联系,概述了三维粗糙度参数在制造业、生物医疗、摩擦学与材料科学等领域的广泛应用,并进一步指出了三维表面粗糙度表征和应用的发展方向。未来随着相关研究(比如,三维测量的溯源性、重复性、参数表征体系等问题)的深入以及三维表面测量手段的发展,三维表面粗糙度参数也将不断完善和推广,并更多地与实际功能相结合来预测并指导生产,确保工件的表面质量。     

基于BP神经网络的车削Ti6Al4V高温钛合金表面粗糙度预测

针对Ti6 Al4 V高温钛合金轴类零件的车削加工过程,设计了Ti6Al4V高温钛合金全因素车削实验,对不同车削参数下表面粗糙度的数值进行了测量,然后以车削参数为输入变量,以表面粗糙度为响应,建立了神经网络预测模型。然后在同等条件下实施验证实验,验证了神经网络模型的预测精度。结果显示,文中研究建立的神经网络模型可以根据切削变量准确预测机械零件表面粗糙度。研究结果可为现场生产选择合适的切削参数提供理论指导,从而实现机械零件表面粗糙度的预测和控制。     

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.