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针对主元分析(Principal component analysis, PCA)和局部保持投影(Locality preserving projections, LPP)方法在降维过程中分别只能保留数据集的整体信息和局部信息,提出一种基于局部整体结构保持投影的贝叶斯故障检测与辨识方法(Local and global structure preserving projections and bayes, LGSPP-Bayes)。首先,将正常工况操作下的原始数据通过局部整体结构保持投影方法投影到低维特征空间,得到高维到低维的数据转换矩阵;然后通过设计贝叶斯分类器来进行故障检测;最后当检测到故障后通过计算贝叶斯分类函数的大小来识别故障种类。将LGSPP-Bayes方法应用于TE过程,仿真结果表明对故障的检测优于其他方法,并且可以很好地将故障种类识别出来。 相似文献
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配电网故障识别、分类与定位对快速隔离故障和保证电网安全运行具有重要意义。以大数据驱动法为基础,提出了最少测量单元选择和区域最佳节点选择两种算法,两种算法基于分类特征评估法,在节点的选择策略上有所不同。分别使用决策树分类器和随机森林分类器验证算法性能,在仅使用7%的节点数据时算法1的最高准确率达91%,算法2使用16%节点数据的最高精度达到85%。实验结果表明,提出的算法无需使用全部节点的数据,可以在系统观测性较低的情况下,实现配电网馈线故障线路智能识别定位,具有测量节点数量少、准确率高等优势。 相似文献
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在分布式系统中,系统的规模庞大,结构复杂,这使得故障数据的收集十分困难;为了对分布式系统进行故障诊断,文章提出了一种基于不完全故障数据的故障诊断方法;首先,应用非对称比较方法进行系统的故障诊断;其次,将系统的故障诊断转化为一个二分类问题;最后,根据系统运行的部分症状数据,应用线性支持向量机模型对系统中的节点状态进行分类;模拟实验表明,文章提出的方法能有效的识别出系统中的故障;此外为了进一步提高该方法的执行效率,可以采用系统的部分症状数据将故障节点限定在一定的范围内。 相似文献
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针对车辆被盗、非授权驾驶等车辆安全问题和公车私用现象,提出基于GPS技术实时地进行车辆跟踪和定位,实现车辆轨迹汇报、防盗等功能。在Linux环境下,使用C语言编写了一套简单的车辆定位系统,系统采用GPS模块,实时地采集车辆的经纬度、海拔高度、车辆行驶速度等信息,实现了车辆定位信息的记录、输出、锁定、打印功能,并通过TCP协议将车辆监控数据上传到网页上,实现让监控人员可以清晰地查看车辆行驶状况的功能。并使用QT设计了一个显示界面输出定位信息,同时实现了根据时间将符合条件的定位数据进行筛选的功能。 相似文献
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现有的车牌定位方法几乎都需要先对白天夜晚的场景进行分类,在图像中存在其他灰度剧烈变化区域时,这种场景分类容易影响到车牌定位的准确率;为了对获取到的车辆图像进行准确地定位,提出了一种改进的灰度跳变车牌定位算法,首先加入了光照补偿,使得不需要对白天和晚上的场景进行分类;然后进行了长竖线的噪声去除,可以在背景比较复杂的情况下准确定位车牌;并对精确定位出的车牌进行边框的去除,有利于下一步的字符分割;另外,对OpenCV计算机视觉库的库函数的利用,算法的复杂度得到了简化,从而更好地满足了车牌识别系统的实时性;通过对出入口处采集到的分辨率为704×576的300张图片进行测试,定位率高于95%,对白天和夜晚获取的图像有很好的适应性,满足设计要求。 相似文献
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为了降低光纤光缆故障率和缩短光缆网络故障诊断时间,提出了一种基于光功率测试和光时域反射仪的光纤故障监测方法;利用光功率测试技术对光缆性能进行实时监控并预警光缆故障;分析光纤功率衰减的原因,计算得到光缆修理增加的长度,设计了修正故障地点的算法;当光缆网络发生故障时,利用光时域反射仪测试故障位置,并利用误差检测算法对电缆衰减进行分析排除,对故障地点进行故障位置修正以便快速抢修;结果表明,该方法可以降低光缆网络故障率,在故障定位中可以提高光缆故障定位的精度,计算的故障位置与实际故障位置的误差不超过10 m,可以进行实时快速的维修,对于运营时间较长的光缆网络的效果更明显,具有较好的应用价值。 相似文献
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以飞机导线短路故障和断路故障为研究对象,目的在于寻求一种测试方法能够提高应用时域反射测量原理进行故障诊断与定位的精度。按照实际机场工程应用背景,设计了以便携式工控机为控制核心、以LabVIEW为驱动软件的飞机导线故障诊断与定位系统。根据信号传播特性,提出了基于互相关算法的故障定位方法,消除了系统误差的影响。计算机仿真和实物测试结果表明该系统具有测试过程方便、准确性高的优点,为提高民航机务维修质量具有促进作用。 相似文献
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Huaiqian Bao Zhaoting Shi Jinrui Wang Zongzhen Zhang Guowei Zhang 《Entropy (Basel, Switzerland)》2021,23(8)
Fault diagnosis of mechanical equipment is mainly based on the contact measurement and analysis of vibration signals. In some special working conditions, the non-contact fault diagnosis method represented by the measurement of acoustic signals can make up for the lack of contact testing. However, its engineering application value is greatly restricted due to the low signal-to-noise ratio (SNR) of the acoustic signal. To solve this deficiency, a novel fault diagnosis method based on the generalized matrix norm sparse filtering (GMNSF) is proposed in this paper. Specially, the generalized matrix norm is introduced into the sparse filtering to seek the optimal sparse feature distribution to overcome the defect of low SNR of acoustic signals. Firstly, the collected acoustic signals are randomly overlapped to form the sample fragment data set. Then, three constraints are imposed on the multi-period data set by the GMNSF model to extract the sparse features in the sample. Finally, softmax is used to as a classifier to categorize different fault types. The diagnostic performance of the proposed method is verified by the bearing and planetary gear datasets. Results show that the GMNSF model has good feature extraction ability performance and anti-noise ability than other traditional methods. 相似文献
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故障的自动诊断和修复是云计算提供持续服务的关键。为了提高云环境下故障自动诊断的性能,本文提出了一种包含相似性替代图和检测图的故障诊断框架。首先,根据相似性将系统的运行指标和事件构成替代图,对替代图中的节点进行分组,使得同一组中的节点可以相互替代。其次,根据事件的时间关系将故障表示为事件的序列,通过排名的方法识别出关键事件并以此构成故障模式。最后,提出了一种基于贝叶斯方法的故障诊断算法。实验表明,本文提出的故障诊断方法与著名的fingerprints方法相比,故障诊断的准确性更高,诊断效率更快。 相似文献
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在地铁屏蔽门系统的故障诊断中,传统方法存在效率低、人工负担重等缺陷。为此,设计了基于故障树的故障诊断专家系统。先用屏蔽门的资料构建出扩展故障树,然后使用早期不交化和模块化等方法将其简化成基本故障树,求出最小割集。在故障树的基础上,设计了专家系统的知识获取和表示机制,建立了知识库。在构建推理机时,采用了双向推理、全自动推理、半自动推理、人工回溯等策略,提高了诊断效率和可信度。该系统可与综合监控系统进行接口,能对相关信息进行推理分析,对潜在故障进行预警,对已发生故障进行快速定位和诊断,出具故障报告和处理建议书,并提供故障模拟及培训功能。试用者的反馈意见表明该系统具有较好的实用价值。 相似文献
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工作流系统的故障自动诊断和定位是云计算环境提供持续服务的基础。为了提高工作流系统的故障诊断准确性,本文提出了一种基于有色Petri网的故障诊断方法。首先,用开放世系模型对工作流进行建模。然后,提出了一种基于有色Petri网的故障模型。最后,将工作流的开放世系模型转化为有色Petri网故障模型,并提出了相应的多故障诊断方法。实验表明,本文提出的方法不仅故障定位的准确率和执行效率高于相关算法,还能有效的识别系统中的多个故障。 相似文献
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GAO Hui-Fen TAO Rui-Bao 《理论物理通讯》2006,46(11)
The electronic states in Thus-Morse chain (TMC) and generalized Fibonacci chain (GFC) are studied by solving eigenequation and using transfer matrix method. Two model Hamiltonians are studied. One contains the nearest neighbor (n.n.) hopping terms only and the other has additionally next nearest neighbor (n.n.n.) hopping terms. Based on the transfer matrix method, a criterion of transition from the extended to the localized states is suggested for GFC and TMC. The numerical calculation shows the existence of both extended and localized states in pure aperiodic system. A random potential is introduced to the diagonal term of the Hamiltonian and then the extended states are always changed to be localized. The exponents related to the localization length as a function of randomness are calculated. For different kinds of aperiodic chain, the critical value of randomness for the transition from extended to the localized states are found to be zero, consistent with the case of ordinary one-dimensional systems. 相似文献
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GAO Hui-Fen TAO Rui-Bao 《理论物理通讯》2006,46(5):929-934
The electronic states in Thus-Morse chain (TMC) and generalized Fibonacci chain (GFC) are studied by solving eigenequation and using transfer matrix method. Two model Hamiltonians are studied. One contains the nearest neighbor (n.n.) hopping terms only and the other has additionally next nearest neighbor (n.n.n.) hopping terms. Based on the transfer matrix method, a criterion of transition from the extended to the localized states is suggested for CFC and TMC. The numerical calculation shows the existence of both extended and localized states in pure aperiodic system. A random potential is introduced to the diagonal term of the Hamiltonian and then the extended states are always changed to be localized. The exponents related to the localization length as a function of randomness are calculated. For different kinds of aperiodic chain, the critical value of randomness for the transition from extended to the localized states are found to be zero, consistent with the case of ordinary one-dimensional systems. 相似文献
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Kazue Kudo 《Entropy (Basel, Switzerland)》2022,24(8)
Detecting many-body localization (MBL) typically requires the calculation of high-energy eigenstates using numerical approaches. This study investigates methods that assume the use of a quantum device to detect disorder-induced localization. Numerical simulations for small systems demonstrate how the magnetization and twist overlap, which can be easily obtained from the measurement of qubits in a quantum device, changing from the thermal phase to the localized phase. The twist overlap evaluated using the wave function at the end of the time evolution behaves similarly to the one evaluated with eigenstates in the middle of the energy spectrum under a specific condition. The twist overlap evaluated using the wave function after time evolution for many disorder realizations is a promising probe for detecting MBL in quantum computing approaches. 相似文献