A multi-scale temporal convolutional capsule network with parameter-free attention module-dynamic routing for intelligent diagnosis of rolling bearing

Abstract We proposed a multi-scale temporal convolutional capsule network model coupled with a parameter-free attention module and dynamic routing mechanism to analyze complex vibration signals for diagnosing the health of bearings. The proposed method utilizes a capsule network as the fundamental architecture. Instead of a convolutional neural network, a temporal convolutional network is employed. Additionally, a multi-scale feature fusion module is integrated into the capsule network structure to dynamically extract various layers of features from fault samples, enhancing the discriminatory capability of abnormal data. Subsequently, the parameter-free attention module and dynamic routing mechanism are employed to construct digital capsules. This allows the smallest unit capsule in a single layer to carry more information, enhance the similarity between the instance primary capsule and the fault capsule, reduce the interference of irrelevant features to the model, and improve the accuracy of fault type recognition. Finally, a multi-scale temporal convolutional capsule network model that integrates feature extraction and pattern recognition is established to perform end-to-end diagnosis of the bearing. Experimental findings suggest that the proposed method outperforms other deep learning methods in terms of accuracy and robustness. It can provide a theoretical basis and implementation path for the detection and diagnosis of train wheelset bearing time series abnormal data.