SAE和BiLSTM-SA在轴承剩余寿命预测中的研究

Application of SAE and BiLSTM-SA for Bearing Residual Life Prediction

  • 摘要: 在轴承剩余寿命预测中,传统方法存在轴承振动信号的多域特征信息冗余与高维特征的降维问题。为了解决这一问题,提出基于稀疏自编码器(SAE)特征融合与双向长短期记忆网络(BiLSTM)并结合自注意力机制(SA)的预测方法。首先,对原始信号进行多域特征提取,构建包含时域、频域和时频域指标的初始特征集合;然后,基于特征相关性、鲁棒性和单调性三个维度建立综合评价体系,筛选出评分高于预设阈值的敏感退化特征作为模型输入,并通过SAE对时域、频域及时频域提取的特征进行融合降维,得到低维的融合特征。最后,将融合特征输入到BiLSTM-SA模块中,进一步提取时序信息并进行特征权重分配,并在PHM2012数据集上进行验证。结果表明,该方法与与BiLSTM-SA、SAE-BiLSTM和SAE-BiGRU三种模型相比,所提方法在多个评价指标上均展现出更优异的性能,证明其对轴承剩余寿命预测的有效性。

     

    Abstract: In the prediction of the remaining life of bearings, the traditional method has the problem of information redundancy in the multi-domain features of bearing vibration signals and dimensionality reduction of high-dimensional features. In order to solve this problem, a prediction method based on Sparse Autoencoders (SAE) feature fusion and Bi-directional Long Short-term Memory (BiLSTM) combined with Self-Attention (SA) is proposed. Prediction method. First, multi-domain feature extraction is performed on the original signal to construct an initial feature set containing time, frequency and time-frequency domain metrics; then, a comprehensive evaluation system is established based on the three dimensions of feature relevance, robustness and monotonicity, and sensitive degraded features with scores higher than the preset thresholds are screened as the input to the model, and the features extracted from time, frequency and time-frequency domains are fused and downgraded by SAE to obtain the low-dimensional fusion features. Finally, the fused features are input into the BiLSTM-SA module to further extract the timing information and assign feature weights, and validated on the PHM2012 dataset. The results show that the proposed method exhibits better performance in several evaluation indexes compared with the three models with BiLSTM-SA, SAE-BiLSTM and SAE-BiGRU, proving its effectiveness in predicting the remaining life of bearings.

     

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