Vehicle-mounted highway tunnel deformation detection method

Abstract

The invention discloses a vehicle-mounted highway tunnel deformation detection method. The method comprises the following steps: constructing a binocular line laser vision system; the binocular line laser vision system comprises two global exposure cameras and a linear laser arranged between the two global exposure cameras, and laser output by the linear laser is parallel to a perpendicular bisector of a connecting line of optical centers of the two global exposure cameras; a plurality of binocular laser vision systems are arranged and installed on a vehicle-mounted platform which runs along the center line of the tunnel at a constant speed according to the shape of the inner contour of the section of the highway tunnel, and three-dimensional coordinate information of tunnel lining surface points is obtained in real time through the binocular laser vision systems. The visual field of each binocular laser visual system directly faces different areas of the tunnel section, it is guaranteed that the measurement precision in the visual field of the camera is consistent, the requirement for maximizing the visual field of the camera is met, and the measurement precision is improved. The technical problem that the vehicle-mounted highway tunnel section deformation measurement precision is not high in the prior art is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of highway tunnel civil construction structure detection, and in particular is a vehicle-mounted highway tunnel deformation detection method. Background Art

[0002] The measurement of the clearance dimensions of the main tunnel of the civil structure of a highway tunnel is an important part of the regular inspection of highway tunnels. The measurement of the clearance dimensions of the main tunnel requires accurate measurement of the deformation of the tunnel section. Currently, it can only be measured manually using a cross-section meter or a manual total station. Manual measurement has major drawbacks. First, it is difficult to ensure that all the measured points are on the same section. Second, the manual measurement speed is very slow. Finally, the point density obtained by manual measurement is too low, making it difficult to accurately calculate the shape and dimensions of the tunnel section. When measuring the deformation dimensions of highway tunnels by vehicle-mounted methods, conventional three-dimensional vision systems are difficult to achieve millimeter-level measurement accuracy due to the long object distance, and the detection speed is difficult to meet the requirements. Summary of the invention

[0003] In view of the shortcomings of the prior art, the object of the present invention is to provide a vehicle-mounted highway tunnel deformation detection method to solve the technical problem of low accuracy in measuring cross-sectional deformation of vehicle-mounted highway tunnels in the prior art.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions to achieve the above problems:

[0005] A vehicle-mounted highway tunnel deformation detection method specifically comprises the following steps:

[0006] Step 1: Build a binocular line laser vision system;

[0007] The binocular line laser vision system comprises two global exposure cameras and a line laser arranged between the two cameras, wherein the laser output by the line laser is parallel to the perpendicular bisector of the line connecting the optical centers of the two global exposure cameras;

[0008] Step 2: multiple binocular line laser vision systems are arranged according to the shape of the inner contour of the highway tunnel section and installed on a vehicle-mounted platform that travels at a constant speed along the center line of the tunnel. The three-dimensional coordinate information of the surface points of the tunnel lining is obtained in real time by using the multiple binocular line laser vision systems, that is, the three-dimensional coordinate information of multiple tunnel sections is obtained;

[0009] The inner profile of the highway tunnel section includes a vault and a pair of haunches and a pair of arch feet symmetrically arranged at both ends of the vault;

[0010] Step 3, performing denoising processing on the three-dimensional coordinate information of one of the tunnel sections obtained in step 2 to obtain the true three-dimensional coordinate information of the tunnel section;

[0011] Step 4, using the least square method based on geometric distance to fit the real three-dimensional coordinate information of the tunnel section obtained in step 3, to obtain a tunnel section shape contour curve;

[0012] Step 5: compare the tunnel section shape contour curve obtained in step 4 with the standard tunnel section contour curve point by point to determine whether the tunnel section is deformed and the amount of deformation;

[0013] Step 6, repeating steps 3 to 5 to obtain the deformation of all tunnel sections, that is, the deformation of the vehicle-mounted highway tunnel.

[0014] The present invention also includes the following technical features:

[0015] Step 2 specifically includes the following steps:

[0016] Step 2.1, respectively aligning the viewing angles of the plurality of binocular line laser vision systems with the chord lengths corresponding to the arch top, arch waist and arch foot; and calculating the viewing angles of each binocular line laser vision system and its installation position on the vehicle-mounted platform according to the chord lengths corresponding to the arch top, arch waist and arch foot;

[0017] Step 2.2, each binocular line laser vision system starts to collect the three-dimensional coordinates of the points on the tunnel section with the camera coordinate system as the origin;

[0018] Step 2.3, unify the three-dimensional coordinates of the points of the same tunnel section collected by each binocular line laser vision system into a common coordinate system, that is, obtain the three-dimensional coordinate information of one tunnel section, thereby obtaining the three-dimensional coordinate information of multiple tunnel sections.

[0019] Step three specifically includes the following steps:

[0020] Step 3.1, calculate the distance change Δd between a point on the tunnel section and the origin of the common coordinate system according to the following formula: i , and take it as the average of the distance differences between this point and its adjacent points;

[0021]

[0022] d i represents the distance between the i-th point on the tunnel section and the origin of the common coordinate system, i = 1, 2, 3…, m, where m is a positive integer;

[0023] Step 3.2, set the judgment threshold D, and judge the distance change value Δd calculated in step 3.1 i Whether Δd is satisfied i ≤D, if it is, the point is considered to be a valid point on the tunnel section, otherwise it is considered to be an interference point on the tunnel section. By eliminating the interference point, the real three-dimensional coordinate information of the tunnel section is obtained.

[0024] Compared with the prior art, the present invention has the following beneficial technical effects:

[0025] (I) In the present invention, when installing the binocular line laser vision system, the field of view of each binocular line laser vision system is directed to different areas of the tunnel section, thereby ensuring consistent measurement accuracy within the camera field of view and meeting the requirement of maximizing the camera field of view, thereby improving measurement accuracy; and solving the technical problem of low measurement accuracy of vehicle-mounted highway tunnel section deformation in the prior art.

[0026] (II) The present invention unifies the three-dimensional coordinates of tunnel section points collected by multiple binocular line laser vision systems, avoiding the subsequent data splicing of the three-dimensional coordinate points obtained by each binocular line laser vision system, and improving the efficiency of data processing.

[0027] (III) The present invention adopts a filtering method based on the distance change value to eliminate interference points on the tunnel section, eliminate the error of tunnel section fitting, and greatly improve the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the schematic diagram of binocular line laser vision system;

[0029] Figure 2 It is the internal 3D imaging principle diagram of the binocular line laser vision system;

[0030] Figure 3 This is the installation diagram of the binocular line laser vision system;

[0031] Figure 4 It is a schematic diagram of the correspondence between the binocular line laser vision system and the inner contour of the highway tunnel section.

[0032] The specific contents of the present invention are further explained in detail below in conjunction with embodiments. DETAILED DESCRIPTION

[0033] It should be noted that, unless otherwise specified, all components in the present invention are components known in the art.

[0034] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0035] The present invention provides a vehicle-mounted highway tunnel deformation detection method, which specifically comprises the following steps:

[0036] Step 1: Build a binocular line laser vision system;

[0037] The binocular line laser vision system includes two global exposure cameras and a line laser arranged between the two cameras, wherein the laser output by the line laser is parallel to the perpendicular midline of the line connecting the optical centers of the two global exposure cameras;

[0038] Step 2: multiple binocular line laser vision systems are arranged according to the shape of the inner contour of the highway tunnel section and installed on a vehicle-mounted platform that travels at a constant speed along the center line of the tunnel. The three-dimensional coordinate information of the surface points of the tunnel lining is obtained in real time by using the multiple binocular line laser vision systems, that is, the three-dimensional coordinate information of multiple tunnel sections is obtained;

[0039] The inner profile of the highway tunnel section includes the arch and a pair of arch waists and a pair of arch feet symmetrically arranged at both ends of the arch;

[0040] Step 3, performing denoising processing on the three-dimensional coordinate information of one of the tunnel sections obtained in step 2 to obtain the true three-dimensional coordinate information of the tunnel section;

[0041] Step 4, using the least square method based on geometric distance to fit the real three-dimensional coordinate information of the tunnel section obtained in step 3, to obtain a tunnel section shape contour curve;

[0042] Step 5: compare the tunnel section shape contour curve obtained in step 4 with the standard tunnel section contour curve point by point to determine whether the tunnel section is deformed and the amount of deformation;

[0043] Step 6, repeating steps 3 to 5 to obtain the deformation of all tunnel sections, that is, the deformation of the vehicle-mounted highway tunnel.

[0044] In the above technical solution, when installing the binocular line laser vision system, the field of view of each binocular line laser vision system is directed to different areas of the tunnel section, thereby ensuring consistent measurement accuracy within the camera field of view, meeting the requirement of maximizing the camera field of view, and improving measurement accuracy; solving the technical problem of low measurement accuracy of vehicle-mounted highway tunnel section deformation in the prior art.

[0045] The principle of binocular line laser vision system is as follows Figure 1 As shown in Figure 1, the factors that affect the measurement accuracy of the binocular vision system are the binocular camera pupil distance T and the parallax d. By increasing the camera pupil distance T and improving the camera resolution, the required measurement accuracy Z can be obtained.

[0046]

[0047] Where: f represents the focal length;

[0048] exist Figure 1 and Figure 2In the figure, P is the target point in space, Pl is the imaging point of P in the left camera coordinate system, xl is the x-axis coordinate value of Pl, Pr is the imaging point of P in the right camera coordinate system, xr is the x-axis coordinate value of Pr. Ol is the optical center of the left camera, Or is the optical center of the right camera, and f is the focal length of the camera.

[0049] Taking into account the installation space limitations on the vehicle, the camera pupil distance T must be within a certain range. The larger the camera resolution, the better. However, increased resolution will lead to increased hardware costs, so you can choose according to the specific situation.

[0050] Step 2 specifically includes the following steps:

[0051] Step 2.1, respectively align the viewing angles of multiple binocular line laser vision systems with the chord lengths corresponding to the arch top, arch waist and arch foot; and calculate the viewing angles of each binocular line laser vision system and its installation position on the vehicle-mounted platform according to the chord lengths corresponding to the arch top, arch waist and arch foot;

[0052] Step 2.2, each binocular line laser vision system starts to collect the three-dimensional coordinates of the points on the tunnel section with the camera coordinate system as the origin;

[0053] Step 2.3, unify the three-dimensional coordinates of the points of the same tunnel section collected by each binocular line laser vision system into a common coordinate system, that is, obtain the three-dimensional coordinate information of one tunnel section, thereby obtaining the three-dimensional coordinate information of multiple tunnel sections.

[0054] In the above technical solution, the three-dimensional coordinates of the tunnel section points collected by multiple binocular line laser vision systems are unified, avoiding the subsequent data splicing of the three-dimensional coordinate points obtained by each binocular line laser vision system, thereby improving the efficiency of data processing.

[0055] The arch top, arch waist, side walls and arch foot correspond to arcs of different diameters respectively, so that the camera's field of view is directly opposite to the chord length of each arc of the tunnel, ensuring the measurement accuracy of the binocular line laser vision system and maximizing the camera's field of view.

[0056] If 5 binocular line laser vision systems are used, according to Figure 4 Arrange them in the manner shown in the figure, use the three-dimensional coordinate system translation and rotation formula, according to the installation angle and position of the binocular line laser vision system, transform the five binocular line laser vision systems into a common coordinate system centered on the intersection of the tunnel centerline and the arch line ( Figure 3 right-hand coordinate system shown).

[0057] In step 2.1, the chord length is determined according to the arc angles corresponding to the arch top, arch waist and arch foot. The chord length is the field of view height of the binocular line laser vision system. The viewing angle of the binocular line laser vision system can be calculated according to the field of view height. The installation position of the binocular line laser vision system can be calculated according to the chord length position and the viewing angle of the binocular line laser vision system.

[0058] For example, in the section above the arch line of a highway tunnel, five arcs are divided according to the angle ranges corresponding to the arch top, arch waist and arch foot, and the angle corresponding to each arc is 45°. In order to ensure that the Z-axis measurement accuracy of each camera is evenly distributed, the camera is installed on the perpendicular midline of the chord length of the arc. The installation positions of the five cameras can be determined based on the camera object distance Z. By calculation, it can be determined that Figure 4 In polar coordinates, the corresponding polar diameter of binocular line laser vision system 1 and binocular line laser vision system 5 is R, and the corresponding polar angle is α 1 , α 5 , the corresponding polar diameter of binocular line laser vision system 2, binocular line laser vision system 3 and binocular line laser vision system 4 is r, and the corresponding polar angle is α 2 , α 3 , α 4 .

[0059] Step three specifically includes the following steps:

[0060] Step 3.1, calculate the distance change Δd between a point on the tunnel section and the origin of the common coordinate system according to the following formula: i , and take it as the average of the distance differences between this point and its adjacent points;

[0061]

[0062] d i represents the distance between the i-th point on the tunnel section and the origin of the common coordinate system, i = 1, 2, 3…, m, where m is a positive integer;

[0063] Step 3.2, set the judgment threshold D, and judge the distance change value Δd calculated in step 3.1 i Whether Δd is satisfied i ≤D, if it is, the point is considered to be a valid point on the tunnel section, otherwise it is considered to be an interference point on the tunnel section. By eliminating the interference point, the real three-dimensional coordinate information of the tunnel section is obtained.

[0064] In the above technical solution, considering that the points collected on the real tunnel section may have interference points caused by the facilities in the tunnel, a filtering method based on the distance change value is adopted to eliminate the interference points on the tunnel section and eliminate the error of tunnel section fitting, thereby greatly improving the measurement accuracy.

Claims

1. A vehicle-mounted highway tunnel deformation detection method, characterized in that: The specific steps include: Step 1: Build a binocular line laser vision system; The binocular line laser vision system comprises two global exposure cameras and a line laser arranged between the two cameras, wherein the laser output by the line laser is parallel to the perpendicular bisector of the line connecting the optical centers of the two global exposure cameras; Step 2: multiple binocular line laser vision systems are arranged according to the shape of the inner contour of the highway tunnel section and installed on a vehicle-mounted platform that travels at a constant speed along the center line of the tunnel. The three-dimensional coordinate information of the surface points of the tunnel lining is obtained in real time by using the multiple binocular line laser vision systems, that is, the three-dimensional coordinate information of multiple tunnel sections is obtained; The inner profile of the highway tunnel section includes a vault and a pair of waists and a pair of feet symmetrically arranged at both ends of the vault; Step 3, performing denoising processing on the three-dimensional coordinate information of one of the tunnel sections obtained in step 2 to obtain the true three-dimensional coordinate information of the tunnel section; Step 4, using the least square method based on geometric distance to fit the real three-dimensional coordinate information of the tunnel section obtained in step 3, to obtain a tunnel section shape contour curve; Step 5: compare the tunnel section shape contour curve obtained in step 4 with the standard tunnel section contour curve point by point to determine whether the tunnel section is deformed and the amount of deformation; Step 6, repeating steps 3 to 5 to obtain the deformation of all tunnel sections, that is, the deformation of the vehicle-mounted highway tunnel.

2. The vehicle-mounted highway tunnel deformation detection method according to claim 1, characterized in that: Step 2 specifically includes the following steps: Step 2.1, respectively aligning the viewing angles of the plurality of binocular line laser vision systems with the chord lengths corresponding to the arch top, arch waist and arch foot; and calculating the viewing angles of each binocular line laser vision system and its installation position on the vehicle-mounted platform according to the chord lengths corresponding to the arch top, arch waist and arch foot; Step 2.2, each binocular line laser vision system starts to collect the three-dimensional coordinates of the points on the tunnel section with the camera coordinate system as the origin; Step 2.3, unify the three-dimensional coordinates of the points of the same tunnel section collected by each binocular line laser vision system into a common coordinate system, that is, obtain the three-dimensional coordinate information of one tunnel section, thereby obtaining the three-dimensional coordinate information of multiple tunnel sections.

3. The vehicle-mounted highway tunnel deformation detection method according to claim 2, characterized in that: Step three specifically includes the following steps: Step 3.1, calculate the distance change Δd between a point on the tunnel section and the origin of the common coordinate system according to the following formula: i , and take it as the average of the distance differences between this point and its adjacent points; d i represents the distance between the i-th point on the tunnel section and the origin of the common coordinate system, i = 1, 2, 3…, m, where m is a positive integer; Step 3.2, set the judgment threshold D, and judge the distance change value Δd calculated in step 3.1 i Whether Δd is satisfied i ≤D, if it is, the point is considered to be a valid point on the tunnel section, otherwise it is considered to be an interference point on the tunnel section. By eliminating the interference point, the real three-dimensional coordinate information of the tunnel section is obtained.

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