In-situ monitoring of clamp-repair-induced displacements in the submarine pipeline using a MEMS accelerometer array: A sea trial

Abstract

The positioning and displacement monitoring of submarine pipelines is crucial for delivering operational feedback and early warning during its external structural repair processes, particularly in turbid sea areas reliant on diver operations. However, conventional numerical simulation and engineering geophysical techniques are unable to obtain real-time state data amidst repairs. In this study, we develop a monitoring system based on Micro-Electro-Mechanical Systems accelerometer arrays (MEMS-AA) to capture positional and displacement changes in the pipeline. By employing a positioning ring to connect the MEMS-AA with the pipeline, the spatial attitude changes in the MEMS-AA can accurately reflect the displacement of the pipeline. Moreover, a novel method is introduced to reconstruct the spatial attitude of the MEMS-AA, which solves the rotation matrix by the three-axis components of the accelerometer in the gravity field utilizing the greedy search algorithm. Through simulations, we validated the accuracy and effectiveness of the proposed method under the influence of varying ocean noises. The sea trials conducted in Hangzhou Bay demonstrate that our monitoring system can successfully capture real-time pipeline displacement associated with repair operations, providing valuable guidance for engineering operations to ensure the structural integrity of the pipeline.