共查询到20条相似文献,搜索用时 281 毫秒
1.
航空发动机转子振动信号的早期故障分析 总被引:1,自引:0,他引:1
由于飞机涡扇发动机是旋转动力机械,早期故障振动信号具有周期性的特点,可将多重自相关用于检测微弱周期性振动信号;针对某型航空发动机空中停车前的早期故障振动信号,通过多重自相关运算,再对信号进行频谱分析,就能准确检测出淹没于强噪声中的微弱周期性信号的频率信息和幅值信息;多重自相关检测方法能够从复杂的航空发动机振动信号中提取出早期的微弱故障信号,从而对早期故障进行有效的分析。 相似文献
2.
军用航空发动机振动问题十分突出,是困扰设计、研制、生产和使用新一代发动机的瓶颈。分析论述了高质量数据采集是发动机振动故障监控的关键、基于振动故障机理和数据驱动的智能诊断、人工自愈原理与振动故障自愈调控系统、航空发动机整机动平衡与自动平衡等原理和技术,并对其团队40年从事状态监测诊断的研究成果及工程应用作简要回顾。提出了未来航空发动机振动故障监控智能化的发展目标和建议。 相似文献
3.
随着飞机多电全电技术的迅猛发展,电力系统在飞机中的重要程度不断提升,而电弧故障是航空电力系统多发的一类电气故障,会引起飞机火灾,轻则烧毁线路,重则引起飞机坠毁。因此,航空交流故障电弧的研究对保障飞机电力系统的安全十分重要。针对传统航空交流故障电弧模型种类单一、难以准确模拟真实故障电弧的特点,基于航空交流故障电弧试验标准下点接触电极、点接触截断和松动接线柱试验中得到的故障电弧电压、电流特性进行分析后,提出模型改进方法,形成航空交流电弧仿真优化策略,从而涵盖所提航空交流电弧试验标准下的故障电弧特性。通过MATLAB/Simulink完成了电弧模型的搭建,对电弧数据及模型仿真结果进行特征量提取及比较,验证了航空交流故障电弧模型仿真策略和方法的有效性。 相似文献
4.
5.
基于小波包分析的航空发动机故障诊断 总被引:2,自引:1,他引:2
航空发动机是一种复杂的旋转机械,故障种类多面且难以辨别。为了保定飞行安全,对航空发动机的故障进行正确、快速地检测,在分析航空发动机故障特征的基础上,利用发动机振动信号的时域指标判断发动机工作是否正常,再对存在故障的发动机振动信号进行小波包分解,作出频带能量图来进一步识别故障。按上述方法对某型涡轮风扇发动机在飞行中空中停车的振动信号作了分析,准确地识别出了故障。结果表明,小波包分解方法进行航空发动机故障诊断具有简单、直观的实际应用价值。 相似文献
6.
根据人耳听觉特性,利用Mel倒谱系数提取有利于发动机振动故障识别的特征;前向神经网络的反向传播算法对类别数目小、但分类困难的模式识别问题有良好的分类效果;针对Mel倒谱系数分析提取的发动机振动故障分类的特征,分别采用BP网络和RBF网络对飞机发动机振动故障进行识别;结果表明:Mel倒谱系数的维数可以改变,选择合适的的Mel特征参数可以有效地提高发动机故障的识别率;RBF网络的故障识别率较高。 相似文献
7.
8.
在飞行实时状态监控过程中,强震动环境下的发动机碰摩故障检测的准确性,关系到飞行的安全.在强震动环境下,发动机转静容易发生碰摩故障,多个碰摩故障往往是同时发生的,但是,故障的振动信号之间不存在之间关联.碰摩故障特征彼此独立,故障特征数据之间缺少可直接建立的关联.传统的故障挖掘方法在发动机转静碰摩故障检测的过程中,只能 根据振动信号对这种故障进行检测,振动信号本身存在很多干扰,也很难包括所有的碰摩故障特征,导致故障检测不准确.为解决上述问题,提出采用改进关联规则挖掘的强震动环境下的发动机碰摩故障检测方法.针对飞机发动机碰摩数据进行关联聚类处理,获取样本空间的分类矩阵,并对发动机碰摩数据进行更新.根据更新结果,计算发动机碰摩数据关联概率值,得到概率决策,针对飞行器碰摩数据进行关联规则挖掘,实现发动机碰摩数据故障优化检测.实验结果表明,利用改进关联规则算法进行强震动环境下的发动机转静碰摩故障检测,极大的缩短了检测时间,降低了漏检率,提高了检测精确度. 相似文献
9.
在灰色预测模型的基础上,提出了改进背景值和初始值两种优化形式,对灰色系统进行优化,并应用小波包分解技术提取发动机转子振动信号的故障特征作为灰色预测系统的输入值,实现了对发动机转子的故障预测;通过实验仿真证明,这个优化灰色预测模型预测精度高,误差小,应用于航空发动机转子故障预测是完全可行和有效的. 相似文献
10.
11.
飞机发动机故障往往表现出一种故障表征出多种特征信号,同一特征信号还可能反映了不同的故障的特点,而传统的基于灰色理论的飞机发动机故障预测由于只考虑表征发动机故障的一个特征参数或单独考虑几个特征参数,使得预测的准确性不能满足实际工程需要。针对某型发动机故障,借鉴灰色预测建模和信息融合的思想,提出了基于多故障特征参数的发动机故障预测模型,使得多个相关特征参数时间序列不仅可以为各自的预测提供相关信息,也可为其他序列预测提供必要的信息,增加了预测的准确性。仿真验证结果表明,该预测模型具有较高的预测准确性,是一个有效的预测模型。 相似文献
12.
EGT(Exhaust Gas Temperature,排气温度)测量通道故障是一种典型的航空发动机测量系统故障,如果试验过程中不能及时发现,就存在不能及时排除EGT超温、发动机喘振、发动机异常停车等故障的可能,造成重大安全隐患。通过对EGT测量通道故障现象和数据的分析,提出了一种EGT测量通道故障模糊神经网络检测算法。该算法将高压转速偏差、低压转速偏差和排气温度偏差作为模糊逻辑系统的输入参数,通过模糊推理实现故障检测。高压转速、低压转速和排气温度的估计值通过试飞数据训练的神经网络估计模型获得。理论分析和试飞数据验证结果表明,该方法具备实时检测EGT测量通道故障的能力,且具有良好的稳定性,可以满足工程应用要求。 相似文献
13.
Kexin Zhang Bin Lin Jixin Chen Xinlong Wu Chao Lu Desheng Zheng Lulu Tian 《计算机系统科学与工程》2022,42(1):351-360
Deep learning techniques have outstanding performance in feature extraction and model fitting. In the field of aero-engine fault diagnosis, the introduction of deep learning technology is of great significance. The aero-engine is the heart of the aircraft, and its stable operation is the primary guarantee of the aircraft. In order to ensure the normal operation of the aircraft, it is necessary to study and diagnose the faults of the aero-engine. Among the many engine failures, the one that occurs more frequently and is more hazardous is the wheeze, which often poses a great threat to flight safety. On the basis of analyzing the mechanism of aero-engine surge, an aero-engine surge fault diagnosis method based on deep learning technology is proposed. In this paper, key sensor data are obtained by analyzing different engine sensor data. An aero-engine surge dataset acquisition algorithm (ASDA) is proposed to sample the fault and normal points to generate the training set, validation set and test set. Based on neural network models such as one-dimensional convolutional neural network (1D-CNN), convolutional neural network (RNN), and long-short memory neural network (LSTM), different neural network optimization algorithms are selected to achieve fault diagnosis and classification. The experimental results show that the deep learning technique has good effect in aero-engine surge fault diagnosis. The aero-engine surge fault diagnosis network (ASFDN) proposed in this paper achieves better results. Through training, the network achieves more than 99% classification accuracy for the test set. 相似文献
14.
针对支持向量机算法存在的不足,研究了一种基于稀疏贝叶斯框架的机器学习方法——相关向量机在航空发动机故障检测中的应用。排气温度是进行发动机监控与故障诊断的重要依据,应用相关向量机对其进行预测。通过仿真实验,证明了相关向量机方法在样本数据较少的情况下只产生了很少的相关向量,并且能够及时准确地预测出发动机排气温度;同时可以使用真实值与预测值的相对误差作为系统是否发生故障的判断依据。 相似文献
15.
16.
Jane Huffman Hayes Inies R. Chemannoor E. Ashlee Holbrook 《Software Testing, Verification and Reliability》2011,21(4):299-325
Fault links represent relationships between the types of code faults, or defects, and the types of components in which faults are detected. For example, our prior work validated that a fault link exists between Controller components and Control/Logic faults (such as unreachable code). Fault link information can guide code reviews, walkthroughs, testing, maintenance, and can advise fault seeding. In this paper, we use fault links to augment code reviews. Two experiments were undertaken to evaluate the usefulness of fault links, one with 26 Computer Science students and another with 24 software engineering professionals. The first experiment showed that fault link information assisted in finding more total defects and more ‘hard to detect’ defects, in the same amount of time, in a Java component of an online course management application. The experiment was repeated with professionals, adding a second Java component from the same application. For the second experiment, more total defects were found by the participants using fault link information for one of the two components and more hard to detect defects were found, in the same amount of time, in both Java components. The group using fault link information for code walkthroughs found, on average, 1.7–2 times more faults and 2–3 times more hard faults than the control group. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
17.
针对流线型AUV舵故障,提出了基于Elman神经网络的故障诊断方法。基于蚁群算法优化改进型Elman神经网络,建立了AUV角速度运动模型,通过蚁群算法和梯度下降法对改进型Elman神经网络训练的对比分析,验证了蚁群算法优化的改进型Elman神经网络具有训练速度快,不易陷入最优解等特点。提出了基于角速度残差检测舵故障,再通过定角度航行和定速直航的主动诊断方式,判定舵故障类型的故障诊断方法,探讨了基于角速度残差和角度残差的变化趋势来诊断舵卡死和舵变形故障的故障决策方法。对流线型AUV的舵变形及舵卡死故障进行了水池模拟实验,实验结果验证了所提方法的有效性。 相似文献
18.
19.
Panayiotis M. Papadopoulos Vasso Reppa Marios M. Polycarpou Christos G. Panayiotou 《IEEE/CAA Journal of Automatica Sinica》2020,7(3):638-655
The enormous energy use of the building sector and the requirements for indoor living quality that aim to improve occupants’ productivity and health, prioritize Smart Buildings as an emerging technology. The Heating, Ventilation and Air-Conditioning (HVAC) system is considered one of the most critical and essential parts in buildings since it consumes the largest amount of energy and is responsible for humans comfort. Due to the intermittent operation of HVAC systems, faults are more likely to occur, possibly increasing eventually building’s energy consumption and/or downgrading indoor living quality. The complexity and large scale nature of HVAC systems complicate the diagnosis of faults in a centralized framework. This paper presents a distributed intelligent fault diagnosis algorithm for detecting and isolating multiple sensor faults in large-scale HVAC systems. Modeling the HVAC system as a network of interconnected subsystems allows the design of a set of distributed sensor fault diagnosis agents capable of isolating multiple sensor faults by applying a combinatorial decision logic and diagnostic reasoning. The performance of the proposed method is investigated with respect to robustness, fault detectability and scalability. Simulations are used to illustrate the effectiveness of the proposed method in the presence of multiple sensor faults applied to a 83-zone HVAC system and to evaluate the sensitivity of the method with respect to sensor noise variance. 相似文献