基于循环神经网络的输电线路绝缘子缺陷检测研究

传统输电线路绝缘子缺陷检测方法在应用过程中容易受外界因素干扰,导致缺陷检测速度慢,为此提出基于循环神经网络的输电线路绝缘子缺陷检测方法。对采集的输电线路绝缘子图像预处理,根据处理后的图像利用循环神经网络确定绝缘子缺陷特征,以此对绝缘子缺陷位置进行定位,从而实现输电线路绝缘子缺陷检测。实验结果表明,与实验对比方法相比,基于循环神经网络的输电线路绝缘子缺陷检测方法在绝缘子缺陷检测过程中的速度更快,实际应用效果较好。     

浅谈输电线路中红外测温技术的应用

论述了红外测温的工作原理及诊断方法,重点介绍了输电线路设备开展红外测温检测时常用的方法,并对各种方法进行了比较分析。介绍了江门局输电设备红外检测中发现的发热缺陷实例,对引起线路设备发热的常见原因进行了分析。     

输电线路智能型液压修补机视觉检测算法研究

为了提高输电线路的供电可靠性,降低输电线路由于运行时间长、外部气候条件恶劣以及电磁环境复杂等造成的导线故障,采用输电线路智能型液压修补机代替人工作业进而降低电网人身风险事故。进行了基于Faster R-CNN的输电线路智能型液压修补机视觉检测算法研究;建立了基于Faster R-CNN的螺栓与导线缺陷检测模型,将训练好的Faster R-CNN导线缺陷检测模型在福建某110 kV输电线路上完成作业实验,证明了所建立的基于Faster R-CNN的输电线路智能型液压修补机视觉检测算法的有效性。     

基于深度学习算法的高压输电线路隐患自动检测方法

为实现输电线路多元状态的全面、准确检测,提高线路运行的安全性和稳定性,文章提出了一种基于深度学习算法的高压输电线路隐患自动检测方法。通过卷积神经网络构建模型,提取输电线路图像运行特征,并对该特征分类识别,实现对线路潜在隐患问题的自动检测。实验结果表明,该方法进行自动检测得到的准确率为98%,查全率为96%,查准率为97%,F1分数为97%,且将其应用于不同隐患类型的识别后,准确率均高于95%。该方法为电力系统的智能化检测提供了有效的技术支持。     

基于机器视觉的表面缺陷检测方法研究进展

基于机器视觉的表面缺陷检测以无接触、无损伤、自动化程度高及安全可靠等突出优点被广泛应用于各种工业场景中,尤其随着深度学习技术的快速发展,视觉缺陷检测有助于提高产品及装备的智能化水平。综述分析了表面缺陷检测的常用方法、通用数据集、检测结果评价指标和现阶段面临的关键问题。首先,将缺陷检测方法分为传统基于图像处理的缺陷检测、基于传统机器学习模型的缺陷检测及基于深度学习的缺陷检测,并对各种方法进一步细分归类和对比分析,总结了每种方法的优缺点和适用场景;然后,对目前常用的缺陷检测结果评价方法做出了描述,进一步探讨了表面缺陷检测应用在实际工业产品检测过程中关键问题——小样本问题,重点剖析了小样本问题的解决方法和无监督学习在解决这类问题上的优势;最后,从提高缺陷检测方法的工业适用性角度展望了下一步研究方向。     

基于深度学习的表面缺陷检测技术研究进展

随着计算机视觉技术的快速发展,基于深度学习的表面缺陷检测技术实现了爆发式的应用,并逐步成为了主流发展方向。基于深度学习的缺陷检测技术可以近似为计算机视觉任务中的分类、检测、分割等任务,其主要目的是找出物体表面缺陷的类别和所在位置,相较于传统图像处理方法,深度学习在特征提取能力和环境适应能力上优势明显。以缺陷数据标签类型为依据,对近年来基于深度学习的表面缺陷检测技术进行梳理划分,总结目前技术的优点与不足,重点阐述了监督学习下的三种缺陷检测方法。探讨了表面缺陷检测技术面临的小样本以及不平衡样本等关键问题：对于小样本问题目前有结构优化、数据增广、迁移学习等解决方法;针对不平衡样本问题,介绍了近年来热点的无监督、弱监督与半监督学习模型。随后介绍了常用的工业表面缺陷数据集并展现了近年来提出的算法在NEU数据集上的应用效果。最后对进一步的研究工作提出展望,希望能给缺陷检测研究提供有意义的参考。     

一种输电线路三跨点下工程机械的改进Faster-RCNN检测方法

为解决输电线路三跨点下由于工程机械入侵导致的跳闸问题,提出一种基于改进Faster-RCNN的大型机具检测算法.该方法以深度学习目标检测算法中的Faster R-CNN作为基本模型,首先研究了不同特征提取网络对模型检测准确度的影响,然后考虑到检测目标与模型的适配问题,使用k-means++算法对输电线路监控数据集中入侵...     

±800 kV特高压直流换流站阀厅换流变端子金具缺陷分析及优化设计

特高压直流输电线路工程换流站阀厅的换流变和阀塔是阀厅中关键且贵重的设备,其安装不可避免地存在允许范围内的误差,多台设备的累积误差可能造成连通过流的金具无法安装。鉴于此,通过对换流变端子金具进行优化设计,有效解决了累积误差造成实际安装距离和理论设计存在偏差导致的金具无法安装问题。     

基于机器视觉的表面缺陷检测方法研究进展

在半导体、PCB、汽车装配、液晶屏、3C、光伏电池、纺织等行业中,产品外观与产品性能有着千丝万缕的联系。表面缺陷检测是阻止残次品流入市场的重要手段。利用机器视觉的技术进行检测效率高、成本低,是未来发展的主要方向。本文综述了近十年来基于机器视觉的表面缺陷检测方法的研究进展。首先给出了缺陷的定义、分类以及缺陷检测的一般步骤;然后重点阐述了使用传统图像处理方式、机器学习、深度学习进行缺陷检测的原理,并比较和分析了优缺点,其中传统图像处理方式分为分割与特征提取两个部分,机器学习包含无监督学习和有监督学习两大类,深度学习主要囊括了检测、分割及分类的大部分主流网络;随后介绍了30种工业缺陷数据集以及性能评价指标;最后指出缺陷检测方法目前存在的问题,对进一步的工作进行了展望。     

高压输电线路红外检测技术分析与探索

为了使红外检测技术能够在高压输电线路接头检测方面更深入、更精确地应用,结合目前红外检测现状,对近年来高压输电线路耐张线夹、跳线线夹、接续管等线路金具的典型检测案例及在实际检测过程中影响红外检测的原因进行了分析,为今后如何开展红外检测工作、如何进一步加强红外检测在高压输电线路上的应用、如何预防高压输电线路接头发热提供了一定的参考。     

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.