A Method for 3D Geometric Reconstruction of Tunnel

Abstract

The present invention proposes a tunnel three-dimensional geometric reconstruction method that takes into account segment segmentation and segment assembly, including the following steps: (1) a mapping method for expanding the tunnel three-dimensional point cloud to a two-dimensional image; (2) a tunnel image segmentation method; (3) Tunnel segment reconstruction based on model matching. The invention proposes a three-dimensional tunnel geometric model reconstruction method coupled with data and model-driven thinking, and reconstructs a multi-scale shield tunnel geometric model. Based on the data-driven idea, the point cloud is first converted into a binary image, and then the tunnel point cloud is segmented at the ring-by-ring scale and the segment scale by using morphology and template matching algorithms. The sealing grooves and bolt holes between segments are more prominent on the binary image, and the image itself also contains the mapping topology relationship between the original point cloud and pixels. Based on the observation that each ring of the tunnel contains only one capping block, we transformed the segment segmentation problem into a template matching problem under the least squares constraint based on binary images to realize the segmentation of tunnel segments, and then based on the idea of ​​model-driven , the reconstruction problem on the scale of the shield tunnel segment is transformed into the matching problem of the segment point cloud and the model library, the type, size and position of various segments are obtained, and the assembly of the tunnel segment is completed.

Description

technical field [0001] The invention relates to a tunnel three-dimensional geometric reconstruction method considering data-driven segment segmentation and model-driven segment assembly, and belongs to the technical field of laser radar remote sensing data intelligent processing and analysis. Background technique [0002] The subway tunnel is a public transportation system with a complex underground space structure. Due to the influence of comprehensive factors such as ground building loads, soil disturbance, and construction around the tunnel, the shape, size, or spatial position of the tunnel will change. At present, how to efficiently and Accurate monitoring of subway tunnel deformation is a hot and difficult issue in underground engineering research. Traditional tunnel deformation monitoring uses instruments such as total stations, levels, and convergent gauges to periodically collect monitoring point data for analysis of tunnel deformation. The traditional monitoring m...

AI Technical Summary

Problems solved by technology

These emerging technologies reduce manual operations, have a high degree of automation, a short monitoring cycle, strong continuity of monitoring data, and high accuracy, but they also have certain limitations: for example, ground aperture radar needs to arrange monitoring points on the inner wall of the tunnel. Can damage the physical structure of the inner walls of the tunnel

However, the section-based tunnel deformation monitoring method also has great limitations: a) This method is only suitable for the measurement of geometric structures such as tunnel section convergence measurement and chord length measurement, and cannot monitor tunnel lining surface shedding, segment cracks, etc. b) When analyzing the tunnel deformation by fitting the tunnel section, the change of the overall geometric shape of the tunnel section can be monitored, but the changes caused by uneven force cannot be monitored. Local nonlinear changes in the tunnel section; c) As a discrete monitoring method, the section monitoring method ignores the continuity of tunnel deformation

However, this method is very sensitive to the noise of the tunnel lining, and often requires human-computer interaction, which seriously reduces the degree of automation of the method

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