Abstract:
The efficient and reliable intelligent monitoring of long-distance grouting pipelines is crucial for ensuring their normal operation. To address the clogging issues often encountered during the transportation process, a monitoring approach combining Distributed Acoustic Sensing (DAS) technology and a frequency-band-based point cloud registration model (FR-LoFTR-2D) is proposed. A frequency-band denoising module (FR) is used for preprocessing the clogging data, which is then converted into Frequency Band Energy (FBE). Based on this, a point cloud registration model is developed for the recognition of clogging points. Additionally, a camera projection module (2D) is employed to perform dimensionality reduction and spatial point coordinate transformation, improving the visualization of the positioning results. This approach aims to resolve the issue of clogging point localization in long-distance grouting pipelines. To evaluate the proposed technique, experimental models of a 129.71 m outdoor loop pipeline and a 513m industrial loop pipeline were constructed and used for model development and validation. The test results indicate that the FR module can effectively filter out pipeline vibration noise induced by the grouting pump, while preserving the characteristic signals. For the FBE three-dimensional images obtained from the DAS phase conversion, the FR-LoFTR-2D model can effectively achieve feature registration and clogging point localization. In the outdoor loop test and industrial loop test, the model’s clogging point localization accuracy was 92.4% and 89.3%, respectively. When the pipeline length increased by approximately 297%, the model's recognition accuracy decreased by approximately 3.1%. This study applies DAS for full-coverage monitoring of long-distance grouting pipelines and, based on the characteristics of the monitoring data, develops the FR-LoFTR-2D clogging recognition model, providing an intuitive and effective solution for monitoring and clogging point localization in long-distance grouting pipelines.