A method for three-dimensional reconstruction and siltation topography analysis of a multi-beam sonar pipeline

Abstract

This invention belongs to the field of pipeline non-destructive testing and image processing technology, and relates to a method for three-dimensional reconstruction and sedimentation morphology analysis of pipelines using multi-beam sonar. The method performs polar coordinate transformation and intensity annotation on frame-by-frame sonar echo data to generate cross-sectional point clouds; performs rigid registration on adjacent frames and generates confidence metrics based on the median and interquartile range of the residuals; searches for temporally non-adjacent but spatially similar frame pairs to establish loop closure constraints; constructs a pose graph with the poses of each frame as nodes and registration and loop closure constraints as edges, and uses confidence-weighted global optimization to eliminate cumulative drift; and separates the pipe wall and sedimentation surface based on nominal cross-sectional geometric priors combined with echo intensity features and calculates sedimentation morphology parameters. This invention effectively eliminates the global geometric drift caused by the unidirectional accumulation of frame-by-frame registration errors in long-distance pipeline inspection, ensuring the consistency of the elevation benchmark and the reliability of the quantitative analysis of sedimentation morphology.

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