Hoist fault diagnosis method integrating time series signal denoising model
摘要
The vibration time-series signals generated during hoist operation are often accompanied by complex noise, which severely hampers the accurate identification of bearing fault features. Therefore, denoising the time-series signals from hoist operation is crucial to improving the reliability of fault diagnosis. This paper proposes a vibration signal denoising model that integrates U-Net and Transformer architectures. The core design involves inserting multi-layer Transformer encoders into the bottleneck of the U-Net structure. This fusion mechanism leverages the U-Net’s skip connections to preserve high-resolution local signal details while simultaneously utilizing the Transformer’s self-attention mechanism to capture long-range temporal dependencies in the down-sampled features, enabling end-to-end signal denoising that effectively distinguishes periodic fault signatures from noise. Furthermore, a two-stage hoist fault diagnosis method is introduced. First, the proposed denoising model denoises the raw 1D vibration signal. Second, the denoised signal is transformed into a 2D time-frequency representation via Continuous Wavelet Transform (CWT), which is then fed into a ResNet18 model for final fault classification. Comparative evaluations with various common denoising and fault diagnosis algorithms confirm the superiority of the proposed approach. Under both low and high noise conditions, the proposed fault diagnosis method achieves an average accuracy of 99.8%.