Abstract:To address the difficulty of monitoring small leaks in buried gas pipelines, leakage vibration signals are collected by a distributed fiber optic vibration sensing system. These signals are converted into two-dimensional images using continuous wavelet transform. An improved MobileNetV3-Bidirectional Long Short-Term Memory (BiLSTM) network is proposed to identify real-time leakage signals under simulated working conditions. The network possesses memory capabilities for leakage time series and features lightweight recognition. Experimental results show that the network achieves an overall classification accuracy of 95.96% under four leakage conditions. Under a leakage pressure of 0.1 MPa, it realizes reliable identification of micro-leakage with a 1/16 inch aperture. Compared with traditional Convolutional Neural Networks (CNNs), the recognition accuracy improves by about 10%–12%, and the average training speed is significantly increased. The proposed method is expected to meet the monitoring requirements for gas pipeline leakage under low pressure and small aperture conditions.