Bridge underwater pile pier structure defect reconstruction method based on laser scanning device

Abstract

The invention relates to a bridge underwater pile pier structure defect reconstruction method based on a laser scanning device, which comprises a laser scanner and a driving unit which is connected with the laser scanner and drives the laser scanner to slide with an annular first guide rail, the inner wall of the detection frame is fixedly provided with a second guide rail which vertically extends to allow the first guide rail to slide, the second guide rail is internally and vertically provided with a screw rod, and the screw rod drives the first guide rail to slide. The damage position, shape and depth of the pile pier are reconstructed, reconstruction of the bridge underwater pile pier structure appearance defects is achieved, and then a numerical model can be established for calculation and analysis. Compared with an existing reconstruction method, the method has the advantages that the numerical model corresponding to the pile pier structure with the defects can be established, and reliable technical support is provided for safety assessment and maintenance of the bridge structure.

Description

Technical Field

[0001] The invention relates to a method for reconstructing structural defects of an underwater bridge pile pier based on a laser scanning device. Background Art

[0002] As the key load-bearing structure of the bridge, the damage detection and assessment of the underwater pile pier structure is crucial to the service life and safety of the entire bridge. Traditional methods for detecting damage to bridge piers mostly use manual visual inspection or image-based qualitative detection methods. Although these methods can detect cracks, peeling or other surface defects on the surface of the structure to a certain extent, it is difficult to accurately measure the depth and size of the defects.

[0003] In recent years, with the development of laser scanning technology, its application in the field of three-dimensional space mapping and structural reconstruction has gradually become popular. The laser scanning device can quickly obtain three-dimensional point cloud data on the surface of the pile pier, and analyze these data through algorithms to reconstruct the apparent shape and damage characteristics of the pier. However, the existing technology mainly focuses on digitally restoring the original structure and corresponding defects, without considering the computability of the reconstructed model. The restored model cannot establish a corresponding numerical model for calculation and analysis. Traditional underwater pile pier structure detection methods rely on manual detection or image-based surface analysis, which makes it difficult to accurately measure the depth of defects and difficult to model and calculate and analyze pile pier structures based on this.

[0004] To this end, the present invention develops a method for reconstructing structural defects of underwater bridge piles and piers based on a laser scanning device. Summary of the invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a method for reconstructing the defects of underwater pile pier structures of bridges based on a laser scanning device. The method not only has a reasonable structure, but also can quickly and accurately measure the depth size of the apparent defects of the pile pier structure, obtain the detection data of the defect depth, and establish a numerical model of the apparent defects of the underwater pile pier structure of the bridge after coordinate conversion processing of the data. This model can be used for finite element simulation calculations, providing reliable modeling technical support for bridge maintenance and safety assessment.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a detection device based on laser scanning, comprising a laser scanner 1 and a driving unit 3 connected to the laser scanner and driving it to slide on a ring-shaped first guide rail 2, the first guide rail is vertically slidably connected in a detection frame 4, and a second guide rail 5 extending vertically for the first guide rail to slide is fixed on the inner wall of the detection frame, a screw rod 6 is vertically arranged in the second guide rail and drives the first guide rail to slide, the screw rod is rotatably connected in the second guide rail and the end is driven to rotate by a motor, the detection frame and the first guide rail are respectively formed by two groups of half frames 7 and two groups of half rings 8, and a locking assembly 9 for combined locking is provided between the two groups of half frames, and the detection end of the laser scanner faces the axis center of the first guide rail.

[0007] Furthermore, a plurality of sliders 10 are evenly spaced along the outer circumference of the first guide rail, and the sliders are all U-shaped with two ends respectively disposed on both sides of the second guide rail.

[0008] Furthermore, there are four groups of second guide rails, and four groups of corresponding sliders are arranged one by one, among which only two groups of second guide rails away from the locking assembly are provided with screw rods, and the two second guide rails are provided with sliding grooves 12 for the screw rod nuts 11 to pass through to connect the sliders.

[0009] Furthermore, the locking assembly includes a buckle 13 rotatably connected to one half of the frame, the buckle is provided with a through hole 14, and the other half of the frame is provided with a screw hole 15 for the buckle or bolt to pass through for locking.

[0010] Furthermore, buckles and screw holes are provided at the upper and lower ends of the detection frame.

[0011] Furthermore, the driving unit comprises a driving frame 16, which is rotatably connected to a driving wheel 17 that slides along the first guide rail, and the laser scanner is fixedly connected to the driving frame.

[0012] Furthermore, the half rings are semicircular in shape, and the joints of the two groups of half rings correspond to the U-shaped openings of the two sliders, that is, after the two groups of half rings are spliced, the bolts 18 are passed through the U-shaped openings of the sliders to fasten them.

[0013] A working method for a bridge underwater pile pier structure defect reconstruction method based on a laser scanning device is carried out in the following steps: the reconstruction method includes considering the bridge underwater pile pier structure as a cylinder in a polar coordinate system, and the cylinder is curled into a plane based on a spatial rectangular coordinate system. The curling process involves a conversion relationship between the polar coordinate system of the cylinder and the spatial rectangular coordinate system, wherein the x-coordinate and the y-coordinate represent the position of the cylinder surface, and the z-coordinate represents the depth of the defect.

[0014] Furthermore, the z coordinate in the spatial rectangular coordinate system is used to represent the depth of the defect. The defect depth data detected by the laser scanning device is converted into a z coordinate, and the z coordinate value is assigned to the x and y coordinates of the corresponding cylindrical surface position; the coordinates of the point in the spatial rectangular coordinate system are (x, y, z), and the coordinates converted into the polar coordinate system are The conversion process is as follows: Calculate the value of the polar radius (r): Calculate the value of the polar angle (θ): (Note that the range of (θ) is determined by the positive or negative value of (x). If (x<0), Calculate the azimuth Values:

[0015] Further, the assigned x, y, z spatial rectangular coordinate data are converted back into a polar coordinate system to form a reconstructed model of the underwater pile pier structure with defects; that is, the coordinates of the point in the polar coordinate system are set to The coordinates converted into the spatial rectangular coordinate system are ((x, y, z)). The conversion process is as follows: Calculate the value of (x): Calculate the value of (y): Calculate the value of (z):

[0016] Compared with the prior art, the present invention has the following beneficial effects: the depth of the apparent defects of the pile pier to be inspected is measured by a laser scanner, and the driving unit and the lead screw drive the laser scanner to move in the circumferential and vertical directions respectively, so as to achieve a more comprehensive detection of the apparent defects of the pile pier. Compared with manual exploration and measurement, it not only improves the accuracy and efficiency of the detection data, but also reduces the risks brought by manual detection, which is safe and convenient.

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of the structure of a driving unit in an embodiment of the present invention;

[0020] Figure 3 Schematic diagram of the connection of the screw rod in the embodiment of the present invention;

[0021] Figure 4 is a flowchart of a reconstruction method in an embodiment of the present invention;

[0022] Figure 5Schematic diagram of the pile pier structure in the polar coordinate system according to the embodiment of the present invention;

[0023] Figure 6 It is a development diagram of the outer surface of the pile pier in the embodiment of the present invention in a spatial rectangular coordinate system;

[0024] Figure 7 It is a schematic diagram after assigning defect depth in a spatial rectangular coordinate system in an embodiment of the present invention;

[0025] Figure 8 Schematic diagram of the underwater pile pier structure with defects converted into a polar coordinate system in an embodiment of the present invention, that is, a schematic diagram of the reconstructed model.

[0026] In the figure: 1-laser scanner, 2-first guide rail, 3-driving unit, 4-detection frame, 5-second guide rail, 6-screw, 7-half frame, 8-half ring, 9-locking assembly, 10-slider, 11-screw nut, 12-slide groove, 13-buckle, 14-through hole, 15-screw hole, 16-driving frame, 17-driving wheel, 18-bolt. DETAILED DESCRIPTION

[0027] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below with reference to the accompanying drawings for detailed description.

[0028] like Figures 1 to 8 As shown, a method for reconstructing structural defects of underwater bridge piles and piers based on a laser scanning device comprises a laser scanner 1 and a driving unit 3 connected to the laser scanner and driving it to slide on a first circular guide rail 2, wherein the first guide rail is vertically slidably connected in a detection frame 4, a second guide rail 5 vertically extending for the first guide rail to slide is fixed on the inner wall of the detection frame, a screw rod 6 is vertically arranged in the second guide rail and drives the first guide rail to slide, the screw rod is rotatably connected in the second guide rail and the end thereof is driven to rotate by a motor, the detection frame and the first guide rail are respectively formed by two groups of half frames 7 and two groups of half rings 8, and a locking assembly 9 for combined locking is arranged between the two groups of half frames, and the detection end of the laser scanner faces the axis of the first guide rail. The laser scanner can move along the circular direction of the first guide rail to detect the damage condition of the pile pier surface.

[0029] In the embodiment of the present invention, a plurality of sliders 10 are evenly spaced along the outer circumference of the first guide rail. The sliders are all U-shaped and the two ends are respectively arranged on both sides of the second guide rail.

[0030] In the embodiment of the present invention, there are four groups of second guide rails, and four groups of corresponding sliders are arranged one by one, among which only two groups of second guide rails away from the locking assembly are provided with screw rods, and the two second guide rails are provided with sliding grooves 12 for the screw rod nuts 11 to pass through to connect the sliders.

[0031] In the embodiment of the present invention, the locking assembly includes a buckle 13 rotatably connected to one half of the frame, the buckle is provided with a through hole 14, and the other half of the frame is provided with a screw hole 15 for the buckle or bolt to pass through for locking.

[0032] In the embodiment of the present invention, buckles and screw holes are provided at the upper and lower ends of the detection frame.

[0033] In the embodiment of the present invention, the driving unit comprises a driving frame 16, which is rotatably connected to a driving wheel 17 that slides along the first guide rail, and the laser scanner is fixedly connected to the driving frame.

[0034] In the embodiment of the present invention, the half ring is in a semicircular arc shape, and the joints of the two sets of half rings correspond to the U-shaped openings of the two sliders, that is, after the two sets of half rings are spliced, the bolts 18 are passed through the U-shaped openings of the sliders to fasten them.

[0035] The reconstruction method mainly includes the following steps:

[0036] S1: The underwater pile pier structure of the bridge is regarded as a cylindrical model with equal size parameters. By mapping the geometric size characteristics of the cylinder into the polar coordinate system, a complete pile pier structure model is established.

[0037] S2: Based on the polar coordinate system, the surface of the cylinder is rolled up into a plane, which is represented by a spatial rectangular coordinate system. The rolling process involves the conversion between the polar coordinate system and the spatial rectangular coordinate system. In the conversion process, the x-coordinate and y-coordinate of the spatial rectangular coordinate system are used to represent the position coordinates of the surface of the cylinder, and the z-coordinate is used to represent the depth value of the apparent defect of the pile pier. Suppose the coordinates of the point in the spatial rectangular coordinate system are (x, y, z), and the coordinates converted to the polar coordinate system are The conversion process is as follows: Calculate the value of the polar radius (r): Calculate the value of the polar angle (θ): (Note that the range of (θ) is determined by the positive or negative value of (x). If (x<0), Calculate the azimuth Values:

[0038] S3: Obtain the apparent defect depth data of the pile pier by the laser scanning device, and convert the defect depth data into the z coordinate in the spatial rectangular coordinate system. Assign the z coordinate value to the x and y coordinates of the corresponding cylinder surface position, so as to establish a plane model of the defective pile pier structure in the spatial rectangular coordinate system.

[0039] S4: Convert the plane model in the spatial rectangular coordinate system back to the polar coordinate system to generate a reconstructed model of the underwater pile pier structure with defects. That is, the coordinates of the point in the polar coordinate system are The coordinates converted into the spatial rectangular coordinate system are ((x, y, z)). The conversion process is as follows: Calculate the value of (x): Calculate the value of (y): Calculate the value of (z):

[0040] The laser scanner is installed in a waterproof component, which is waterproof. When the laser scanner enters the water to detect the pile, the waterproof component can prevent the laser scanner from directly contacting the water and causing damage. It should be noted that the side of the waterproof component facing the pile is transparent, and the laser emitted by the laser scanner can smoothly reach the surface of the pile through the transparent side for scanning and detection.

[0041] The laser scanner performs laser marking, measures the distance value from the laser scanner to the laser marking, and detects the apparent defect depth of the pile pier through the distance value measured by the laser marking.

[0042] Laser dot measurement technology, especially the method based on point laser, provides an effective solution for measuring the defect depth for the reconstruction of pile pier surface defects. By using point laser technology to measure the pile pier surface, the complex three-dimensional structure problem is simplified into a two-dimensional depth problem for processing. Combined with defect depth information and area recognition technology, the size information parameters of the defect contour can be measured, and then the two-dimensional model of the pile pier surface defect can be analyzed. Not only does it improve the accuracy and efficiency of detection, but it can also be effectively applied to the field of bridge detection, solving problems that are difficult to solve with traditional detection methods. In addition, for the detection of pile pier defect size deviation, two-dimensional laser dot measurement technology can be used for non-contact measurement. This technology obtains accurate laser dot data by scanning the pile pier surface. After processing, the size information of the pile pier and the two-dimensional characteristics of the surface defect can be obtained, thereby evaluating its size deviation. This method avoids the error of manual measurement and improves the efficiency and accuracy of detection. Laser dot measurement technology, especially combined with two-dimensional laser dot technology, provides an efficient and accurate solution for the detection of pile pier surface defects, which is of great significance for ensuring the safety of bridges and extending their service life.

[0043] The working process of the pile pier detection device of this embodiment is as follows: first, the device unlocking buckle is separated in half, and hoisted to the two sides of the pile pier to be detected, close together to enclose it, and then the buckle is locked. At this time, the first guide rail is sleeved on the pile pier. The laser scanner is turned on to perform laser marking on the surface defects of the pile pier. The drive unit is turned on to drive the laser scanner to move along the annular first guide rail (around the outer circumference of the pile pier). At the same time, the screw is turned on to drive the first guide rail to move in the up and down directions. Under the action of the drive unit and the screw, the laser scanner can more comprehensively scan the surface defects of the pile pier and obtain the depth detection data of the surface defects of the pile pier structure.

[0044] The main steps of the pile pier defect reconstruction method of this embodiment are as follows: first, the underwater pile pier structure of the bridge is regarded as a cylindrical model with equal size parameters, and a complete pile pier structure model is established by mapping the geometric size characteristics of the cylinder into the polar coordinate system; secondly, based on the polar coordinate system, the surface of the cylinder is curled and unfolded into a plane, which is represented by the spatial rectangular coordinate system, and the curling process involves the conversion between the polar coordinate system and the spatial rectangular coordinate system. In the conversion process, the x-coordinate and y-coordinate of the spatial rectangular coordinate system are used to represent the position coordinates of the surface of the cylinder, and the z-coordinate is used to represent the depth value of the apparent defect of the pile pier. Then, the apparent defect depth data of the pile pier is obtained by the laser scanning device, and the defect depth data is converted into the z-coordinate in the spatial rectangular coordinate system. The z-coordinate value is assigned to the x- and y-coordinates of the corresponding position of the cylinder surface, so as to establish a plane model of the defective pile pier structure in the spatial rectangular coordinate system. Finally, the plane model in the spatial rectangular coordinate system is converted into the polar coordinate system, so as to generate a reconstructed model of the underwater pile pier structure with defects. The reconstructed model can be used for finite element simulation and numerical calculation, and the safety, ultimate bearing capacity and other index parameters of relevant structural mechanical properties can be evaluated through simulation analysis of defective pile pier structures.

[0045] In this document, unless otherwise specified or limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0046] In this document, the directions or positional relationships indicated by terms such as "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", and "horizontal" are based on the directions or positional relationships shown in the accompanying drawings and are only for the clarity of expressing the technical solutions and the convenience of description, and therefore should not be understood as limitations of the present invention.

[0047] In this document, the terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and may also include additional elements not expressly listed.

[0048] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A detection device based on laser scanning, characterized in that: It includes a laser scanner and a driving unit connected to the laser scanner and driving it to slide with a first annular guide rail, the first guide rail is vertically slidably connected in a detection frame, a second guide rail extending vertically for the first guide rail to slide is fixed on the inner wall of the detection frame, a screw rod is vertically arranged in the second guide rail and drives the first guide rail to slide, the detection frame and the first guide rail are respectively formed by two groups of half frames and two groups of half rings, a locking assembly for combined locking is arranged between the two groups of half frames, and the detection end of the laser scanner faces the axis center of the first guide rail.

2. The detection device based on laser scanning according to claim 1, characterized in that: A plurality of sliding blocks are evenly spaced along the outer circumference of the first guide rail. The sliding blocks are all U-shaped and the two ends are respectively arranged on both sides of the second guide rail.

3. The detection device based on laser scanning according to claim 2, characterized in that: There are four groups of second guide rails in total, and four groups of corresponding sliders are arranged one by one. Among them, only two groups of second guide rails far away from the locking assembly are provided with screw rods, and the two second guide rails are provided with sliding grooves for screw rod nuts to pass through to connect with the sliders.

4. The detection device based on laser scanning according to claim 1, characterized in that: The locking assembly comprises a buckle rotatably connected to one half of the frame, the buckle is provided with a through hole, and the other half of the frame is provided with a screw hole for the buckle or bolt to pass through for locking.

5. The detection device based on laser scanning according to claim 4, characterized in that: Buckles and screw holes are provided at the upper and lower ends of the detection frame.

6. The detection device based on laser scanning according to claim 1, characterized in that: The driving unit comprises a driving frame, the driving frame is externally rotatably connected with a driving wheel that slides along the first guide rail, and the laser scanner is fixedly connected to the driving frame.

7. The detection device based on laser scanning according to claim 2, characterized in that: The half rings are in a semicircular arc shape, and the joints of the two groups of half rings correspond to the U-shaped openings of the two sliders, that is, after the two groups of half rings are spliced, bolts are passed through the U-shaped openings of the sliders to fasten them.

8. A method for reconstructing structural defects of underwater bridge piles and piers based on a laser scanning device, characterized in that: The detection device based on laser scanning as claimed in any one of claims 1 to 7 is used, and the following steps are performed: scanning and measuring the surrounding pile pier of the laser scanner are realized by the driving unit in cooperation with the screw rod; the underwater pile pier structure of the bridge is regarded as a cylindrical model with equal size parameters, and a complete pile pier structure model is established by mapping the geometric size characteristics of the cylinder into the polar coordinate system; The reconstruction method includes treating the underwater pile pier structure of the bridge as a cylinder in a polar coordinate system, and the cylinder is curled into a plane based on the spatial rectangular coordinate system. The curling process involves the conversion relationship between the polar coordinate system of the cylinder and the spatial rectangular coordinate system, where the x-coordinate and the y-coordinate represent the position of the surface of the cylinder, and the z-coordinate represents the depth of the defect.

9. The method for reconstructing underwater bridge pile pier structure defects based on a laser scanning device according to claim 8, characterized in that: The z coordinate in the spatial rectangular coordinate system is used to represent the depth of the defect. The defect depth data detected by the laser scanning device is converted into the z coordinate, and the z coordinate value is assigned to the x and y coordinates of the corresponding cylindrical surface position; the coordinates of the point in the spatial rectangular coordinate system are (x, y, z), and the coordinates converted into the polar coordinate system are (r, , ), the conversion process is as follows: Calculate the value of the polar radius (r): (r = ); Calculate the polar angle ( ) value: ) (Note that the positive and negative values ​​of (x) should be used to determine ( ) value range, if (x<0), you need to ( ) value to adjust); calculate the azimuth ( ) value: ).

10. The method for reconstructing underwater bridge pier structure defects based on a laser scanning device according to claim 9, characterized in that: The assigned x, y, z spatial rectangular coordinate data are converted back into a polar coordinate system to form a reconstruction model of the underwater pile pier structure with defects; that is, the coordinates of the point in the polar coordinate system are (r, , ), converted to the coordinates in the spatial rectangular coordinate system ((x, y, z)), the conversion process is as follows: Calculate the value of (x): (x = r sin( ) cos( )); Calculate the value of (y): (y = r sin( ) sin( )); Calculate the value of (z): (z = r cos( )).

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