改进PSO优化的小波神经网络在压力传感器温度补偿中的研究

针对电阻应变式压力传感器在实际工作环境使用中出现温度漂移,进而影响测量精度的问题,提出了基于粒子群算法(PSO)优化小波神经网络的温度补偿方法,通过PSO算法优化小波神经网络的参数,克服基本人工神经网络收敛速度慢,容易陷入局部极值的缺陷。研究结果表明：该方法能有效地消除环境温度对电阻应变式压力传感器输出的影响,经过温度补偿后其压力传感器的全温区准确度提高到了0.136 4%,温度漂移明显得到改善,提高了压力传感器的稳定性和准确性。     

在线黏度测量中的温度特性研究及其补偿

对一类智能应变黏度传感器的工作原理进行了阐述,解析了影响该传感器温度特性的因素.系统基于温度补偿和差分放大电路的集成实现传感器零漂温度校正,采用DS18B20-PAR单总线温度传感器进行温度测量和基于BP算法的神经网络进行温度补偿和校正,使得黏度传感器的输出信号为测量信号的单值函数,消除了温度的影响,试验结果证实提高了测量精度.     

基于MAX1452硅压力传感器温度补偿系统的设计

针对硅压阻式传感器存在的温度漂移误差和输出信号的非线性提出了利用MAX1452温度调理芯片进行补偿的方案。描述了传感器温度补偿系统的整体构架,着重阐述了MAX1452的补偿原理以及对传感器的补偿过程。测试结果表明传感器经过补偿以后,在-40~80℃的温度范围内输出的信号与压力成较好的线性关系,测量的误差小于0.8%。     

智能化差动电容角位移传感器的研究

介绍了一种智能化差动电容角位移传感器，它利用PICl6F877单片机实现对差动电容角位移传感器敏感元件的输出进行智能化处理。优点是减少电气干扰和温度漂移，消除电路网络参数的不对称影响，提高传感器的稳定性和可靠性。     

LabVIEW下基于BP神经网络的温度补偿虚拟压力测量系统设计

压力传感器的输入输出通常存在非线性，而且输出会因工作环境温度的改变，使其零点、灵敏度均发生漂移。为消除温度对压力传感器测量结果的影响，在LabVIEW下实现虚拟压力测量系统，并应用反向传播（BP，Back Propagation）神经网络，通过样本对网络进行训练，并将该BP网络以动态链接库的形式提供给LabVIEW调用。测试结果表明温度补偿效果非常好，同时具备传感器测量值的转换和非线性校正功能，该应用BP神经网络的虚拟压力测量系统具有很大的实用价值。     

光寻址电位传感器的噪声分析与信号处理方法研究

鉴于光寻址电位传感器(LAPS)的响应信号较弱,传统的抽取频域基波分量的方法易受信号漂移和随机噪声的影响,提出了一种基于频域分量均方根和卡尔曼滤波的两步信号处理方法。基于光寻址电位传感器件的理论模型构建了其等效电路模型,推导得到输出信号的表达式,分析了漂移与噪声产生的原因及其抑制方法。通过实验检测了不同pH值的溶液,并采集了系统输出的光电流信号。求取信号傅里叶变换后频域中的基波分量、二次谐波分量、三次谐波分量的谱线幅值的均方根,然后对归一化电流-偏压(I-V)特性曲线进行卡尔曼滤波。实验结果表明,相对于单纯抽取基波分量的方法,基于频域分量均方根和卡尔曼滤波的两步信号处理方法使检测结果的均方差(MSE)降低了97%,显著减少了信号漂移和随机噪声对检测结果的影响。     

一种大刚度传动轴的扭矩测量方法

介绍一种适用于大刚度传动轴扭矩测量的扭传感器，可以在不同降低传动轴刚度的条件下获得较大的扭矩输出信号。     

一种新型磁电感应式动态非接触扭矩传感器

对一种基于非晶态合金及磁电感应的非接触测量扭矩传感器进行了研究。首先,介绍了传感器的结构和原理。然后,分析了传感器的输出特性、灵敏度及非线性误差。最后,在扭矩试验机上进行了试验,通过试验分析了这种扭矩传感器的测量精度以及气隙、线圈匝数、激磁电流强度、频率对测量灵敏度的影响。试验结果表明,设计的传感器具有输出信号强、结构简单、便于安装、同时还能测量转速等特点。     

硅荷重传感器

本文提出了一种新型的扩散硅荷重传感器。介绍了一种微计算机软件补偿技术,以消除或减小由扩散硅器件的输出温度影响、零点温度影响、零点漂移和非线性带来的误差,从而提高了硅荷重传感器的精度。     

一种可弥补信号缺陷的细分方法

由于受到光栅制造、传感器设计和调试等技术的限制,光栅传感器不可避免地存在某些缺陷,如信号幅值不稳定、信号中心电平漂移等。这些缺陷直接影响到整个光栅测量系统的精度,成为光栅测量系统最普遍存在的误差源。本文详细给出了一种新的细分方法,使用此方法可有效地消除信号幅值不稳定和信号中心电平漂移对系统精度的影响     

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.