航空学报 > 2022, Vol. 43 Issue (9): 625479-625479   doi: 10.7527/S1000-6893.2021.25479

基于提升卷积神经网络的航空发动机高速轴承智能故障诊断

韩淞宇1, 邵海东1, 姜洪开2, 张笑阳3   

  1. 1. 湖南大学 机械与运载工程学院, 长沙 410082;
    2. 西北工业大学 民航学院, 西安 710072;
    3. 中国航空工业集团公司西安航空计算技术研究所 民机事业部, 西安 710065
  • 收稿日期:2021-03-12 修回日期:2021-03-30 出版日期:2022-09-15 发布日期:2021-06-18
  • 通讯作者: 邵海东,E-mail:hdshao@hnu.edu.cn E-mail:hdshao@hnu.edu.cn
  • 基金资助:
    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)

Intelligent fault diagnosis of aero-engine high-speed bearings using enhanced CNN

HAN Songyu1, SHAO Haidong1, JIANG Hongkai2, ZHANG Xiaoyang3   

  1. 1. College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China;
    2. School of Civil Aviation, Northwestern Polytechnical University, Xi'an 710072, China;
    3. Civil Aircraft Department, AVIC Xi'an Aeronautics Computing Technique Research Institute, Xi'an 710065, China
  • Received:2021-03-12 Revised:2021-03-30 Online:2022-09-15 Published:2021-06-18
  • Supported by:
    National Key Research and Development Program of China (2020YFB1712100); National Natural Science Foundation of China (51905160); Natural Science Foundation of Hunan Province (2020JJ5072)

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。

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

Abstract: 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.

Key words: aero-engine high-speed bearings, intelligent fault diagnosis, enhanced convolutional neural network, unbalanced data, multi-scale feature extraction, adaptive weighting, loss function compensation

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