Wavelet-driven differentiable architecture search for planetary gear fault diagnosis

With the advancement of artificial intelligence and the accumulation of industrial big data, intelligent diagnosis methods based on deep learning have become the mainstream for diagnosing mechanical faults in manufacturing systems. Despite this, developing high-performance neural network models for specific tasks necessitates a substantial amount of expert knowledge. This consumes a considerable amount of time in the trial-and-error process, thereby constraining the progress in neural network development. Neural architecture search (NAS) offers a solution to address this problem. However, the feature extraction operators in the existing NAS search space are primarily imported from other fields, leading to domain bias and a lack of interpretability. To address these challenges, we present a NAS method driven by wavelets. To be specific, the wavelet operators that can extract fault related features from vibration signals is added to the search space, and the gradient optimization strategy is utilized to search the optimal architecture from the hypernet. The effectiveness of the proposed method is validated through a dataset specific to planetary gears. Upon comparison with other models, it is evident that the proposed method exhibits superior performance across all added noise levels.