BWKNet: Toward an interpretable neural network with bi-damped wavelet for fault diagnosis of rolling bearing
摘要
Despite the widespread adoption of convolutional neural networks (CNNs) in bearing fault diagnosis due to their superior nonlinear feature extraction capabilities, the inherent opacity of their end-to-end architecture raises interpretability concerns. To address the mismatch between conventional wavelets (e.g., Morlet, Laplace) and actual bearing fault pulse responses, this study proposes a novel softmax-activated bi-damped wavelet and establishes a physics-informed wavelet convolution layer. We further develop BWKNet – an interpretable model architecture integrating the proposed bi-damped wavelet convolution layer with a ResNet18 backbone enhanced by a plug-and-play lightweight local attention module. Comprehensive evaluations demonstrate the model’s effectiveness, achieving recognition accuracies of 99.86 % on the Case Western Reserve University dataset and 98.15 % on the Nanchang Railway Bureau dataset. The proposed model combines physical interpretability through customized wavelet convolution layer design with data-driven learning capabilities, supported by systematic interpretation via priori empowerment and attributional explanations. This work provides a solution for fault diagnosis interpretability.