摘要
航空发动机轴承长时间工作在高速重载的恶劣条件下,将不可避免地产生性能衰退甚至引发各种故障,自动准确的航空发动机高速轴承故障诊断方法有助于提升运行安全性和维修经济性。航空发动机高速轴承的原始振动信号具有强烈的非平稳性,且其故障样本数量远小于健康样本,传统的智能诊断方法更容易向大样本偏斜,从而导致诊断性能的降低。针对上述问题,提出了一种基于自适应权重和多尺度卷积的提升卷积神经网络(CNN)。首先构造多尺度卷积网络提取故障样本的多尺度特征,挖掘具有识别性的有用信息;然后设计自适应权重单元对多尺度特征进行加权融合,增加重要特征的贡献度,减少非相关特征的影响;最后采用Focal Loss作为损失函数,使训练过程中网络模型更关注故障样本和易混淆样本。通过航空发动机高速轴承振动数据的测试与分析,证实了所提方法在不平衡数据故障诊断任务中的可行性。
Aero-engine bearings usually operate for long hours under harsh conditions of high speed and heavy loads,inevitably leading to performance deterioration and even causing various faults,and automatic and accurate fault diagnosis methods for high-speed aero-engine bearings can help to improve operation safety and maintenance economy.The original vibration signals collected from aero-engine high-speed bearings have strong instability and the number of faulty samples is much smaller than that of healthy ones.The traditional intelligent diagnosis method tends to skew to large samples,thereby inducing degradation in diagnosis performance.To solve the above problem,we propose an enhanced convolutional neural network model based on adaptive weight and multi-scale convolution.A multi-scale convolution network is first constructed to extract multi-scale features of fault samples and mine useful identifying information.An adaptive weight unit is then designed to fuse the multi-scale features to increase the contribution of the important features while reducing the influence of unrelated features.Focal Loss is finally used as the loss function to enable the model to consider the small faulty samples and easily confused samples more.The test and analysis of aero-engine high-speed bearing vibration data confirm the feasibility of the proposed method in fault diagnosis tasks with unbalanced data.
作者
韩淞宇
邵海东
姜洪开
张笑阳
HAN Songyu;SHAO Haidong;JIANG Hongkai;ZHANG Xiaoyang(College of Mechanical and Vehicle Engineering,Hunan University,Changsha 410082,China;School of Civil Aviation,Northwestern Polytechnical University,Xi’an 710072,China;Civil Aircraft Department,AVIC Xi’an Aeronautics Computing Technique Research Institute,Xi’an 710065,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2022年第9期150-163,共14页
Acta Aeronautica et Astronautica Sinica
基金
国家重点研发计划(2020YFB1712100)
国家自然科学基金(51905160)
湖南省自然科学基金(2020JJ5072)。
关键词
航空发动机高速轴承
智能故障诊断
提升卷积神经网络
不平衡数据
多尺度特征提取
自适应权重
损失函数补偿
aero-engine high-speed bearings
intelligent fault diagnosis
enhanced convolutional neural network
unbalanced data
multi-scale feature extraction
adaptive weighting
loss function compensation
