Error analysis of IMU pipeline bending strain detection based on full-scale test

Abstract The strain identification technology based on inertial mapping unit (IMU) internal detectors is currently a widely used internal detection technology for identifying pipeline bending strain both domestically and internationally. It calculates the bending strain of the entire pipeline through the detected centerline coordinate data. However, there are issues such as abnormal vibration and noise during the actual operation of the inertial navigation internal detector, as well as trajectory deviation during the detector’s operation. This issue leads to a certain deviation between the strain detected by IMU and the actual strain of the pipeline. This article utilizes a self-designed full size pipeline bending strain loading device to conduct full size pipeline bending strain tensile tests. Compare the internal detection data obtained from the experiment with the actual bending strain data of the pipeline and conduct error analysis. The research conclusion indicates that as the bending strain increases, the error between the IMU detection strain and the actual strain of the pipeline increases. When there is vibration noise, the maximum error is 0.077% for 0.33% true strain, and the maximum error rate for larger strain segments is 27.1%. The comparison between noise reduction detection data and true strain shows that when the true strain is 0.12%, 0.21%, and 0.33%, the average error is 0.0285%, 0.0315%, and 0.0555%, respectively. The research conclusion provides technical support and guidance for obtaining true strain of pipelines based on IMU internal detection in the future.