差动结构的平面二维时栅位移传感器

为了解决采用两套高精度一维传感、装置测量二维位移时存在的测量系统复杂、检测同步性难保证和解耦运算复杂等问题,提出了一种基于差动结构的二维感应信号直接解耦方法,用于研究一种平面线圈型二维时栅位移传感器。立足于传统电磁式时栅技术,构建了二维位移直接解耦测量模型,并设计了传感器的基本结构。利用ANSYS Maxwell 建立了传感器三维结构模型并进行了电磁仿真,并对仿真结果进行误差分析和溯源。基于此研制了传感器样机并进行了实验。实验结果表明：样机在79.2 mm×79.2 mm测量范围内,X方向误差为91 μm,Y方向误差为74 μm,可实现二维位移同步检测和直接解耦测量,且测量系统结构简单、体积小,对研究更高性能的二维时栅具有重要参考价值。     

可抑制端部效应的平面磁场式直线时栅位移传感器

针对前期研制平面磁场式直线时栅位移传感器存在的端部效应致使匀速运动坐标系均匀度降低的问题,提出了一种抑制平面线圈端部效应的方法,构建均匀性更高的交变磁场,并研制出了一种可抑制端部效应的新型平面直线时栅位移传感器。建立了平面线圈励磁数学模型,分析端部效应对均匀磁场的影响程度,提出了双层互补式激励线圈结构抑制端部效应方案;建立了新型平面直线时栅位移测量模型,采用空间正交的双列激励单元,实现了行波信号的合成并通过仿真验证了方案的有效性;建立了仿真模型,分析端部效应对传感器测量精度的影响,并优化传感器参数;基于PCB工艺制造了量程为228 mm的新型传感器样机并与传统传感器样机展开了对比实验,实验结果表明,新型平面直线时栅位移传感器能够有效地抑制传感器的端部效应,提高测量精度,传感器对极内原始测量精度从±20μm提高到±10μm。     

基于多频磁场耦合的平面二维位移传感器

针对目前光刻机、超精密数控机床等高端超精密装备对于精准平面定位的要求,提出了一种基于多频磁场耦合的平面 二维位移传感器。 传感器组成为定尺和动尺,其中定尺由导磁基体和 X、Y 方向励磁线圈构成,动尺由导磁基体和 X、Y 方向感 应线圈构成。 通过对 X、Y 方向励磁线圈通入正余弦励磁信号,在定尺上构建出多频磁场耦合的二维均匀磁场阵列,动尺感应 出带有位移信息的电信号,经过理论推导和电磁仿真验证了多频磁场直接解耦差动结构和幅值调制解算方法的可行性,并对仿 真误差进行分析,并优化了传感器结构。 最后采用 PCB 工艺制作传感器样机并开展相关实验研究,实验结果表明:传感器在 150 mm×150 mm 的测量范围可对二维位移进行精确测量,其中 X 方向测量精度为±33. 08 μm,Y 方向测量精度为±36. 95 μm,优 化后的传感器样机 X、Y 方向原始对极内位移误差峰峰值在原有基础上降低了 49. 1% 和 50. 7% 。     

基于离散绕组的磁场式时栅位移传感器及误差特性

针对高精度位移传感器难以加工的难题,提出一种基于离散绕组的磁场式时栅位移传感器。通过设计离散激励绕组排布方式与感应绕组的形状控制感应位移信号的变化规律,通过组合测量方式实现精密位移测量。通过理论建模、仿真分析与实验验证揭示了激励信号误差和安装偏差对传感器测量精度的影响规律。实验结果表明：两路激励信号的幅值不等和安装偏差都会在对极内测量精度中直接引入直流分量误差和2次谐波误差,其中2次谐波误差是误差的主要成分。安装偏差越大,2次谐波误差越大,动尺沿Z轴偏摆姿态对测量精度的影响最大,沿Y轴翻转姿态引入的误差次之,沿X轴俯仰姿态引入的误差最小。误差修正后传感器在144 mm的测量范围内,测量误差峰峰值为4.5μm,分辨力为0.15μm。通过毫米级尺寸的激励和感应绕组实现微米级精度测量,可显著降低传感器的制造难度,具有重要的工程应用价值。     

基于平面驻波磁场的二维位移传感器 测量原理与结构优化

在芯片制造、智能制造、航空航天等领域,精密平面定位迫切需要平面两维度位移的同步独立精密测量。本文提出一种基于电磁感应原理的平面位移传感器,由动阵面和定阵面组成。定阵面由m×n个平面螺旋线圈阵列串联而成,通入交变励磁电信号时在测量平面产生平面驻波磁场。动阵面由四个螺旋线圈以2×2矩阵形式排列,感应出振幅随x轴和y轴位移变化的四路调制信号,并利用Cordic算法求解两维度位移量。本文首先介绍了传感器的工作原理,对电磁模型进行有限元分析,并对位移解算算法进行数值模拟。根据仿真结果对测量误差进行分析溯源,优化传感器结构。制作传感器样机开展了实验验证,验证了传感器结构和位移解耦方法的可行性。实验表明,传感器在节距内最大误差为48.7μm,分辨率为0.317μm,在147 mm×147 mm量程范围内,传感器线性度达到0.15%,为高精度电磁感应式平面二维位移传感器的进一步发展提供了理论支撑和实验指导。     

光场式时栅传感器信号产生与采集的硬件系统设计

针对传统光学位移传感器的制造设备昂贵及时栅传感器中存在的抗电磁干扰能力差、制造精度不高等问题,设计了一种基于交变光场时空耦合和光刻技术的光场式时栅传感器。根据光场式时栅传感器测量系统的要求,利用DDS技术生成了光场式时栅的激励信号,并完成了LED光源的驱动电路设计,得到了时栅的交变光场信号;设计了基于硅光电池的光信号采集及调理电路,获得了一路用于位移测量的电行波信号。实验表明:该系统能够稳定工作,在108 mm的测量范围内,光场式时栅的测量精度为±0.5μm。     

基于正交双行波磁场的平面二维时栅位移传感器

针对半导体行业、航空航天等领域对于精密二维位移测量的迫切需求,提出了一种基于正交双行波磁场的平面二维时 栅位移传感器。 传感器由定尺和动尺组成,定尺由导磁基体和沿 x、y 方向排列的两励磁线圈组成,动尺由导磁基体和沿 x、y 方 向排列的两层感应线圈组成。 当励磁线圈通入正余弦励磁信号时,在定尺上方产生分别沿 x 和 y 方向运动的正交双行波磁场。 通过对感应线圈输出的感应电信号进行解算得到 x 和 y 方向的位移值。 首先介绍了传感器的结构和工作原理,对传感器模型 进行了电磁场仿真;然后对仿真误差进行溯源分析,并优化传感器结构;最后采用印刷电路板技术制作了传感器样机,并设计相 应的电气系统进行实验验证。 实验结果表明该传感器在 160 mm×160 mm 测量范围内能够实现平面二维位移测量,x 方向节距 内位移误差峰峰值为 32. 8 μm, y 方向节距内位移误差峰峰值为 34. 5 μm。     

基于平面线圈线阵的直线时栅位移传感器

针对现有磁场式直线时栅位移传感器行波磁场产生过程中,齿槽的存在影响行波磁场的匀速性,提出基于平面线圈线阵的直线时栅位移传感器。无齿槽的结构形式提高了行波磁场的匀速性,可实现大极距下的高精度测量。传感器将施加正交信号的两相励磁线圈相间排列形成平面线圈线阵,产生的行波磁场通过磁场拾取线圈感应出电行波信号,处理后得到位移量。通过电磁场分析软件对传感器进行建模仿真,根据仿真结果得到测量误差;通过理论分析对测量误差进行分析溯源,并根据分析结果对传感器结构进行优化。基于分析和优化结果研制出传感器样机,并进行了精度实验。实验表明,传感器在240 mm内测量精度为±1μm,实现了精密测量。     

基于光敏阵列直接调制的单栅式时栅位移传感器

针对传统叠栅形式光栅存在制造难度大、安装要求高等缺点,提出了一种用时间细分空间的单栅式时栅位移传感器。从光的粒子性出发,分析了用正交变化的光场信号合成光场电行波的方法;用点阵发光二极管(LED)模块作为交变光源,用空间正交的光敏阵列直接耦合光强信号获取了反应空间位移的电行波信号;最后,通过检测电行波信号与激励信号过零点之间的时间差,实现了对空间直线位移的测量。研制了原理样机,采用普通机械加工方法对其进行了实验验证。结果表明,在440mm测量范围内,样机的测量精度可达±2μm。该单栅式时栅位移传感器减少了叠栅式传感器对安装工艺的要求,提高了抗干扰能力;采用的测量技术避免了传统粗光栅技术存在的精度难以提高、动态特性差等缺点,为光学位移测量提供了一种不通过精密机械细分来提高测量精度的方法。     

典型位移传感器分类研究与时栅传感器特点分析

对现有广泛使用的主要位移传感器和全新原理的时栅位移传感器,按其测量基准、测量原理、数学模型和刻划媒介等方面的不同进行了科学分类,分析其间的联系与差别、优势与不足、各自适用的场合等技术特征。介绍时栅在测量原理上的先进性,经权威部门——中国测试技术研究院检定:目前圆式、直线式时栅的测量精度分别达到±0.8″、±0.5μm/m,分辨力分别达到0.1″、0.1μm。为了使时栅的测量精度向纳米级测量精度迈进,对基于电场和光场原理的纳米时栅进行了分析。另外对时栅的衍生技术-寄生式时栅及其在极端特殊环境下的应用前景进行了简单介绍。     

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.