Mobile tunnel laser detection data processing method

Abstract

The invention relates to a mobile tunnel laser detection data processing method. The method comprises steps of acquiring original, actual tunnel section point cloud data; correcting tunnel section mileage data based on accumulated errors; performing tunnel point deformation analysis, convergent diameter analysis, multi-phase data comparison and analysis and comparison and analysis of multiple measurement manners according to point cloud on the inner wall of the tunnel, so as to acquire tunnel deformation situation; determining whether the tunnel section point cloud is within a standard profileenclosed by limiting points by using a horizontal ray method, so as to determine whether invasion points exist; converting section point cloud data into a designed absolute coordinate system, so as to restore a design line type of the tunnel; and performing texture mapping by using an orthogonal projection image of the inner wall of the tunnel so as to acquire a 3D model of the tunnel. In the method, tunnel deformation analysis, mileage correction, boundary detection, recovery of the design line type of the tunnel and 3D modelling of the tunnel can be performed according to the original, actual section, and data is processed rapidly.

Description

technical field [0001] The invention relates to the technical field of tunnel detection data processing, in particular, the invention relates to a method for processing laser detection data of a moving tunnel. Background technique [0002] As the number and scale of tunnels in our country increase year by year, the rapid monitoring and detection of tunnel structure status becomes particularly important. Mobile laser scanning measurement technology is a technology that is more concerned and researched in the industry at present, but in the past, mobile laser detection systems mostly installed scanners on track detection trolleys, and integrated odometers, displacement sensors, inertial navigation systems, GPS, etc. A variety of sensors are designed to obtain tunnel point cloud data in an absolute coordinate system. [0003] Tunnel detection generally characterizes its deformation law by analyzing its cross-section, but the current technology mostly extracts the tunnel cross-...

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Problems solved by technology

The advantage of this method is that the inspection is thorough and comprehensive. The disadvantage is that it consumes more manpower and material resources, and there will be errors in the process of making the limit detection vehicle. For different tunnel conditions, the limit detection vehicle must be stretched. , the detection process is more cumbersome

Moreover, there are few researches on 3D reconstruction of tunnels at present, and most of them are based on professional 3D visualization modeling software for 3D display.

[0006] Chinese invention patent CN104792274A discloses a method for measuring the convergence deformation of a circular tunnel. A three-dimensional laser scanner is used to obtain the coordinates of the working base point and the tunnel point cloud of each station, and the working base point is used as the splicing reference point to merge the tunnel point cloud into In the unified reference coordinate system, the point cloud of multi-ring pipe joints is divided according to the pipe joints. According to the improved cylindrical surface fitting algorithm, the point cloud of one-ring pipe joints is fitted to a cylindrical surface and the coordinates of the pipe joint axis points are extracted. The cylindrical surface is projected onto the plane along the axis of the pipe joint to obtain a two-dimensional tunnel point cloud contour line, which is fitted to an ellipse according to the ellipse fitting algorithm, and the ellipse is expanded along the axis into a three-dimensional elliptical cylinder, and then the three-dimensional convergence of the entire tunnel is obtained Deformation. In this patent, before performing convergent deformation analysis on the tunnel, it is necessary to transform the coordinate system of the point cloud measured by the laser scanner, and also perform ellipse fitting and construct a three-dimensional elliptical cylinder. The process is complicated. low efficiency

[0007] Chinese invention patent CN106548510A discloses a method for generating a shield tunnel structure model, using a three-dimensional laser scanner to scan the tunnel to be modeled to obtain initial point cloud data, determine the three-dimensional axis coordinate data and mileage data of the initial point cloud data, and The initial point cloud data is divided into a plurality of segments, and each segment is assigned a mileage value according to the mileage data, and each segment is obtained according to the mileage value and the three-dimensional axis coordinate data. The cross-sectional point cloud data of the ring segment, parameterizing each of the cross-sectional point cloud data, forming a cross-sectional parameter model of each of the ring segments, and constructing a parameterized family of each of the ring segments, Combine all the described cross-section parameter models to form a tunnel structure model. In this method, when constructing the tunnel model, it is necessary to construct the cross-section parameter models of each ring segment and then combine them, so the time spent is long and the splicing process There will be errors in the model, and the accuracy of the obtained tunnel structure model is low

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