非接触式气动位移传感器的分类

<正> 非接触式气动传感器,由于使用效果好,结构简单,工作可靠等优点,所以在各种自动化生产过程中得到了广泛的应用。它可以高精度地(在十分之几微米以内)测量线值尺寸,检测容易变形的工件,还能在高温、振动和具有放射性条件下工作。按工作原理非接触式气动传感器可以分为下列几种类型。普通型式气动传感器:这种型式气动传感器的工作是根据从测量喷咀出来的气流被测量     

自动测量筛选机的设计

大批量零件在接触检测中存在各种弊端,设计一台提供非接触式自动测量薄壁圆环类零件的自动化机器。该机器实现了零件的自动上料、视觉图像处理、良品和不良品的分拣,大大提高了检测效率和质量。     

面向回转类零件圆度的机器视觉测量方法与试验

针对工程应用中回转类零件的圆度测量精度不高、效率低等问题,提出了基于改进的Zernike矩亚像素边缘特征提取算法的回转类零件圆度视觉测量方法。建立了回转类零件轴截面图像的机器视觉测量系统,在分析零件轴截面图像特征的基础上,将传统的Zernike矩算法与最大类间方差法相结合得到改进的快速算法,提高了亚像素边缘点的定位精度。建立了轴截面圆度测量数学模型,应用标准量块对系统进行标定,实现了回转类零件直径与圆度的非接触式测量。试验结果表明,该方法不仅可使直径与圆度的测量达到亚像素级精度,还避免了传统测量方法造成的低效率与误判,实现了快速、准确、非接触式测量。     

气动内孔测量头和校对规

<正> 气动测量头是气动测量中直接用于测量工件的尺寸、几何形状和位置偏差的传感器.气动内孔测量头用于测量孔尺寸。它是由进气管路、测量喷嘴及测量头体所组成.当被测工件的孔径尺寸变化时,会引起气动量仪上的气动参量变化,从而实现精密测量。气动参量的变化信号是由气动内孔测量头输出的。根据测量的工作原理,气动内孔测量头分为非接触式和接触式两类。     

盘、轴类零件检测平台的研究与应用

根据盘、轴类零件的结构尺寸参数特性,基于三坐标测量机安装高精度转台和机器视觉测量装置,利用高精度转台建立零件测量空间坐标,使加工基准和测量基准重合。通过测量路径规划,实现零件表面质量和形位公差参数的高效、高精度测量,达到零件尺寸的非接触式自动化测量。经实验对比可知,在保证检测质量的前提下,检测效率提升35%以上。     

高精度非接触式自动外径测量方法研究

针对我国目前零件产品在线检测自动化程度不高,无法完全和零件生产的精度和能力相匹配的问题,在研究非接触式测量原理的基础上,对高精度、大直径的零件产品特点进行分析,采用数字CMOS激光传感器的作为测量工具,提出了多台传感器并行的测量方法.同时,在不增加成本的情况下,分析研究了测量精度提升的改进方法.实验结果与分析表明,此高精度非接触式自动外径测量系统可以完成5 μm精度的零件测量,自动判定合格并且声光电的方式报告判定结果.此系统提高了零件产品在线检测自动化程度,避免了人工测量的不足.     

基于CCD成像的外圆纵向磨削表面粗糙度在线测量

为了提高外圆磨削加工零件表面粗糙度的测量效率,可以采用在线测量的方法.基于CCD成像技术,利用激光图谱比较法以及图像傅立叶变换后的能量谱,对外圆纵向磨削后的零件表面粗糙度进行非接触式在线测量,并判定加工零件表面粗糙度的等级.使用的测量方法,可以实现在线检测表面粗糙度的目的,达到了预想的效果.     

圆柱体零件圆度与圆柱度非接触测量系统

圆度和圆柱度是圆柱体零件的重要检测项目.针对目前圆柱体零件圆度与圆柱度采用人工接触式测量,存在效率低、精度差、易损伤零件等缺点,设计了基于激光位移传感器的圆柱体零件圆度与圆柱度非接触测量系统.这一测量系统基于误差分离技术,利用标准球和标准环规测量,分离出偏心误差、回转运动误差、导轨误差,进而提高检测精度.通过自律验证法,基于这一测量系统对不同圆柱体零件进行多组对比检测试验.试验结果表明,这一测量系统检测精度达到10 μm,可以实现圆柱体零件圆度和圆柱度的检测,提高检测效率和检测质量.     

小孔气动塞规的试验研究

成批生产中,小孔孔径通常用塞规测量。测量方法和量具都比较简单。但用塞规测量时松紧不易掌握,容易划伤被测孔表面,塞规本身也易磨损。使用非接触式的气动测量可以克服上述缺点。但是用一般的喷嘴档板气动测量方法,测量小于φ3毫米的小孔时,由于测头小,制造困难,同时测头的变换倍率低,需要配用放大器,因此限制了气动测量的应用。本文提出了一种非接触式的小孔气动塞规测量方法,巧妙地把上述两种方法的长处结合起来。这种方法经过试验研究取得十分满意效果,证明它简单实用,具有较高测量精度。     

火车车轴轴径测量检测装置设计与研究

轴类回转体零件一直是机械设备中一种非常重要的零件,传统的接触式轴径测量方法存在精度低、线形范围小等缺点,激光扫描仪、边缘检测方法等局限于小直径轴径检测。为了提高检测精度以及检测效率,基于机器视觉测量原理,设计了方便于在线非接触式轴径误差检测装置。此装置设计简单、操作方便,经试验验证,可以保证较高的检测精度,且适用于大尺寸轴径测量。     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.