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

Abstract

The present application relates to a kind of bridge underwater pile pier structure defect reconstruction methods based on laser scanning device, including laser scanner and with laser scanner connection and drive its with annular first guide rail sliding drive unit, first guide rail vertical sliding connection in a detection frame, second guide rail is fixed on the inner wall of detection frame and is extended vertically to be used for the sliding of first guide rail, the second guide rail is vertically provided with screw rod and first guide rail is driven to slide by it, the depth data of pile pier apparent defect site is obtained by the above device, data is processed in combination with coordinate conversion, reconstructs the damage location, shape and depth of pile pier, reconstructs the apparent defect of bridge underwater pile pier structure, and then can establish numerical model to calculate and analyze.It is compared with prior art reconstruction method, the numerical model corresponding to the pile pier structure with defect can be established by the present application, to provide reliable technical support for the safety evaluation and maintenance of bridge structure.

Description

TECHNICAL FIELD

[0001] The present application relates to a bridge underwater pile pier structure defect reconstruction method based on a laser scanning device. BACKGROUND

[0002] The bridge underwater pile pier structure is a key load-bearing structure of the bridge, and its damage detection and evaluation are crucial to the service life and safety of the entire bridge. Traditional bridge pier damage detection methods mostly use manual visual inspection or image-based apparent qualitative detection means. These methods can find surface cracks, spalling or other apparent defects of the structure to some extent, but 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 structure reconstruction has gradually become popular. Laser scanning devices can quickly obtain three-dimensional point cloud data of the pile pier surface, and analyze these data through algorithms to reconstruct the apparent shape and damage characteristics of the pier. However, existing technologies mainly focus on digitizing the original structure and corresponding defects, without considering the computability of the reconstructed model, and 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 apparent analysis, which is difficult to accurately measure the depth of the defect, and is difficult to model and calculate and analyze the pile pier structure based on this.

[0004] Therefore, the present application develops a bridge underwater pile pier structure defect reconstruction method based on a laser scanning device. SUMMARY

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

[0006] In order to solve the above technical problems, the technical scheme of the present application is: a detection device based on laser scanning, comprising a laser scanner 1 and a driving unit 3 connected with the laser scanner and driving the laser scanner to slide on a ring-shaped first guide rail 2, the first guide rail vertically slidingly connects 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 lead screw 6 is vertically arranged in the second guide rail and drives the first guide rail to slide, the lead screw is rotationally connected in the second guide rail and the end portion is driven to rotate by a motor, the detection frame and the first guide rail are respectively formed by two sets of half frames 7 and two sets of half rings 8, a locking assembly 9 for combination and locking is arranged between the two sets of half frames, and the detection end of the laser scanner faces the shaft center of the first guide rail.

[0007] Further, the first guide rail is uniformly distributed with a plurality of sliding blocks 10 at intervals along the outer periphery, and the sliding blocks are all U-shaped and arranged at both sides of the second guide rail respectively.

[0008] Further, the second guide rail is provided with four groups, and four groups of sliding blocks are arranged one by one correspondingly, wherein only the two second guide rails away from the locking assembly are provided with lead screws, and the two second guide rails are provided with sliding grooves 12 for the lead screw nut 11 to pass out to connect the sliding blocks.

[0009] Further, the locking assembly comprises a buckle 13 rotationally connected to one of the half frames, a through hole 14 is formed in the buckle, and a screw hole 15 for the lock buckle or bolt to pass through for locking is formed in the other half frame.

[0010] Further, the detection frame is provided with a buckle and a screw hole at the upper and lower ends.

[0011] Further, the driving unit comprises a driving frame 16, a driving wheel 17 sliding along the track of the first guide rail is rotationally connected outside the driving frame, and the laser scanner is fixedly connected to the driving frame.

[0012] Further, the half ring is in the shape of a semicircular arc, and the butt joint of the two sets of half rings corresponds to the U-shaped opening of the two sliding blocks, that is, the two sets of half rings are spliced and are fastened by the bolt 18 transversely passing through the U-shaped opening of the sliding block.

[0013] A working method of a bridge underwater pile pier structure defect reconstruction method based on a laser scanning device, which is performed according to the following steps: the reconstruction method comprises regarding the bridge underwater pile pier structure as a cylinder in a polar coordinate system, taking the space rectangular coordinate system as a reference, curling the cylinder into a plane, and the curling process involves the conversion relationship between the polar coordinate system of the cylinder and the space rectangular coordinate system, wherein 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.

[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 this z-coordinate value is assigned to the x and y coordinates of the corresponding position on the surface of the cylinder. Let the coordinates of a point in the spatial rectangular coordinate system be (x, y, z), which is converted to the coordinates in the polar coordinate system as follows: 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 values ​​for (θ) is determined by the sign of (x). If (x < 0), the range of values ​​for (θ) needs to be adjusted.) (Adjust the value); calculate the azimuth angle. Value:

[0015] Furthermore, the assigned x, y, z spatial rectangular coordinate data are converted back to polar coordinates to form a reconstructed underwater pile pier structure with defects; that is, let the coordinates of the points in the polar coordinate system be... The coordinates are converted to ((x,y,z)) in a Cartesian coordinate system. 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 advantages: by using a laser scanner to measure the depth of surface defects of the pile pier to be inspected, the drive 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 inspection of surface defects of the pile pier. Compared with manual probing and measurement, it not only improves the accuracy of the inspection data and the inspection efficiency, but also reduces the risks brought about by manual inspection, making it safe and convenient.

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

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

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

[0020] Figure 3 This is a schematic diagram of the lead screw connection in an embodiment of the present invention;

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

[0022] Figure 5A schematic view of a pile structure in polar coordinate system in the embodiment of the present application;

[0023] Figure 6 A development view of the outer surface of the pile in the spatial rectangular coordinate system in the embodiment of the present application;

[0024] Figure 7 A schematic view of the defect depth in the spatial rectangular coordinate system in the embodiment of the present application;

[0025] Figure 8 A schematic view of the underwater pile structure with defects in the polar coordinate system in the embodiment of the present application, i.e. a reconstruction model schematic view.

[0026] In the figure: 1-laser scanner, 2-first guide rail, 3-driving unit, 4-detection frame, 5-second guide rail, 6-screw rod, 7-half frame, 8-half ring, 9-locking assembly, 10-sliding block, 11-screw rod nut, 12-sliding 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 application more obvious and easy to understand, the following specific examples are described in detail below, and the drawings are used as reference.

[0028] As shown in Figures 1-8 A bridge underwater pile structure defect reconstruction method based on a laser scanning device, comprising a laser scanner 1 and a driving unit 3 connected with the laser scanner and driving it to slide on the annular first guide rail 2, the first guide rail is vertically slidingly connected in a detection frame 4, a second guide rail 5 extending vertically is fixed on the inner wall of the detection frame for the first guide rail to slide, a screw rod 6 is vertically arranged in the second guide rail and drives the first guide rail to slide, the screw rod is rotationally 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 sets of half frames 7 and two sets of half rings 8, the two sets of half frames are provided with locking assemblies 9 for combination and locking, and the detection end of the laser scanner faces the axis of the first guide rail. The laser scanner can move along the annular direction of the first guide rail to detect the damage of the pile surface.

[0029] In the embodiment of the present application, a plurality of sliding blocks 10 are uniformly distributed along the outer periphery of the first guide rail, and the sliding blocks are U-shaped and arranged at both ends of the second guide rail.

[0030] In the embodiment of the present application, the second guide rail is provided with four groups, and four groups of sliding blocks are arranged one by one, and only the 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 nut 11 to pass out to connect the sliding blocks.

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

[0032] In this embodiment of the invention, the detection frame is provided with buckles and screw holes at both the upper and lower ends.

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

[0034] In this embodiment of the invention, the semi-circular ring is semi-circular in shape, and the joint of the two sets of semi-circular rings corresponds to the U-shaped opening of the two sliders. That is, after the two sets of semi-circular rings are spliced, the bolts 18 pass through the U-shaped opening of the sliders to secure them.

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

[0036] S1: Treat the underwater pile pier structure of the bridge as a cylindrical model with equal dimensional parameters, and establish a complete pile pier structure model by mapping the geometric dimensional features of the cylinder to the polar coordinate system.

[0037] S2: Based on the polar coordinate system, the surface of the cylinder is rolled up and unfolded 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. During the conversion, the x and y coordinates of the spatial rectangular coordinate system are used to represent the position coordinates of the cylinder surface, and the z coordinate is used to represent the depth value of the apparent defects of the pile pier. Let the coordinates of a point in the spatial rectangular coordinate system be (x, y, z), which is converted to the coordinates in the polar coordinate system as follows: 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 values ​​for (θ) is determined by the sign of (x). If (x < 0), the range of values ​​for (θ) needs to be adjusted.) (Adjust the value); calculate the azimuth angle. Value:

[0038] S3: Obtain the depth data of apparent defects on the pile pier using the laser scanning device, and convert the defect depth data into z-coordinates in a spatial rectangular coordinate system. Assign the z-coordinate values ​​to the x and y coordinates of the corresponding cylindrical surface positions, thereby establishing a planar model of the defective pile pier structure in a spatial rectangular coordinate system.

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

[0040] The laser scanner device is in a waterproof member, which is waterproof treated. In the process of detecting the pile pier underwater, the waterproof member can prevent the laser scanner from being damaged by directly contacting water. It should be noted that the side of the waterproof member facing the pile pier is transparent, and the laser emitted by the laser scanner can pass through the transparent side to reach the surface of the pile pier for scanning detection.

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

[0042] Laser dotting measurement technology, especially the point laser-based method, provides an effective solution for measuring defect depth for pile pier surface defect reconstruction. By using point laser technology for pile pier surface measurement, the complex three-dimensional structure problem is simplified to 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 a two-dimensional model of the pile pier surface defect can be analyzed. Not only does it improve the detection accuracy and efficiency, but it can also be effectively applied to the field of bridge detection, solving the problem that traditional detection methods cannot solve. In addition, for the detection of pile pier defect size deviation, two-dimensional laser dotting measurement technology can be used for non-contact measurement. This technology acquires accurate laser dotting data through scanning the pile pier surface, and after processing, the size information of the pile pier and the two-dimensional features of the surface defect can be obtained, thereby evaluating the size deviation. This method avoids the error of manual measurement, improves the efficiency and accuracy of detection. Laser dotting measurement technology, especially combined with two-dimensional laser dotting 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 prolonging their service life.

[0043] The working process of the pile detection device of the embodiment is as follows: first, the device is unlocked, the buckle is opened, and the device is hoisted to the two sides of the pile to be detected, and then the buckle is locked after the two sides are closed to each other, at this time, the first guide rail is sleeved on the pile. The laser scanner is turned on to perform laser dotting on the surface defects of the pile, the driving unit is turned on to drive the laser scanner to move along the annular first guide rail (around the outer periphery of the pile), and the lead screw is turned on to drive the first guide rail to move in the up-down direction. The laser scanner can comprehensively scan the surface defects of the pile under the action of the driving unit and the lead screw, and the depth detection data of the surface defects of the pile structure can be obtained.

[0044] The main steps of the pile defect reconstruction method of the embodiment are as follows: first, the underwater pile structure of the bridge is regarded as a cylindrical model with equal size parameters, the geometric size characteristics of the cylinder are mapped into a polar coordinate system, and a perfect pile structure model is established; second, based on the polar coordinate system, the surface of the cylinder is curled and unfolded into a plane, which is represented by a 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 and y coordinates 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 surface defects of the pile. Then, the depth data of the surface defects of the pile are obtained by the laser scanning device, and the defect depth data are 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 surface position of the cylinder, so as to establish a plane model of the pile structure with defects 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 reconstruction model of the underwater pile structure with defects. The reconstruction model can be used for finite element simulation and numerical calculation, and the safety, ultimate bearing capacity and other related structural mechanical performance index parameters of the pile structure with defects can be evaluated through simulation and analysis of the pile structure with defects.

[0045] In this document, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0046] In this document, the terms "up", "down", "front", "back", "left", "right", "top", "bottom", "inside", "outside", "vertical", "horizontal" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of expressing the technical scheme clearly and conveniently, therefore cannot be understood as a limitation on the present application.

[0047] In this document, the terms "comprise", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0048] The above description is only specific embodiments of the application, but the protection scope of the application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered by the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for reconstructing defects in underwater bridge pier structures based on a laser scanning device, characterized in that: The device includes a laser scanner and a drive unit connected to the laser scanner and driving it to slide on a first annular guide rail. The first guide rail is vertically slidably connected within a detection frame. A second guide rail is fixedly provided on the inner wall of the detection frame, extending vertically to allow the first guide rail to slide. A lead screw is vertically arranged within the second guide rail and drives the first guide rail to slide. The detection frame and the first guide rail are respectively formed by combining two sets of half-frames and two sets of half-rings. A locking assembly for combining and locking is provided between the two sets of half-frames. The detection end of the laser scanner faces the axis of the first guide rail. The method employs the aforementioned laser scanning device and proceeds according to the following steps: A drive unit, in conjunction with a lead screw, scans and measures the surrounding pile pier using a laser scanner; the underwater bridge pile pier structure is treated as a cylindrical model with uniform dimensional parameters, and a complete pile pier structure model is established by mapping the geometric dimensional features of the cylinder to a polar coordinate system; the reconstruction method includes treating the underwater bridge pile pier structure as a cylinder in a polar coordinate system, wherein the cylinder is rolled into a plane based on a spatial rectangular coordinate system. This rolling process involves the conversion relationship between the cylindrical polar coordinate system and the spatial rectangular coordinate system, where the x and y coordinates represent the position of the cylinder's surface. The z-coordinate represents the depth of the defect; 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 scanner is converted into a z-coordinate, and this z-coordinate value is assigned to the x and y coordinates of the corresponding position on the surface of the cylinder. Let the coordinates of a point in the spatial rectangular coordinate system be (x, y, z), which is converted to the coordinates in the polar coordinate system as follows: The conversion process is as follows: Calculate the value of the polar radius r: Calculate the value of the polar angle (θ): Calculate azimuth Value:

2. The method for reconstructing defects in underwater bridge pier structures based on a laser scanning device according to claim 1, characterized in that: The first guide rail has a number of sliders evenly spaced along its outer periphery. The sliders are all U-shaped and their two ends are respectively located on both sides of the second guide rail.

3. The method for reconstructing defects in underwater bridge pier structures based on a laser scanning device according to claim 2, characterized in that: The second guide rail is provided in four sets, and the corresponding slider is provided in four sets. Only the two sets of second guide rails away from the locking component are provided with lead screws. The two second guide rails are provided with grooves for the lead screw nut to pass through to connect with the slider.

4. The method for reconstructing defects in underwater bridge pier structures based on a laser scanning device according to claim 1, characterized in that: The locking assembly includes a buckle rotatably connected to one half of the frame, the buckle having a through hole, and a screw hole on the other half of the frame for a buckle or bolt to pass through for locking.

5. The method for reconstructing defects in underwater bridge pier structures based on a laser scanning device according to claim 4, characterized in that: The detection frame is equipped with buckles and screw holes at both the top and bottom.

6. The method for reconstructing defects in underwater bridge pile pier structures based on a laser scanning device according to claim 1, characterized in that: The drive unit includes a drive frame, on which a drive wheel is rotatably connected and slides along the first guide rail track. The laser scanner is fixedly connected to the drive frame.

7. The method for reconstructing defects in underwater bridge pier structures based on a laser scanning device according to claim 2, characterized in that: The semi-circular ring is semi-circular in shape, and the joint of the two sets of semi-circular rings corresponds to the U-shaped opening of the two sliders. That is, after the two sets of semi-circular rings are spliced, they are fastened by bolts passing through the U-shaped opening of the sliders.

8. The method for reconstructing defects in underwater bridge pile pier structures based on a laser scanning device according to claim 1, characterized in that: The assigned x, y, z spatial rectangular coordinate data are converted back to polar coordinates to form a reconstructed underwater pile pier structure model with defects; that is, let the coordinates of a point in the polar coordinate system be... Convert the coordinates to (x, y, z) in a Cartesian coordinate system. The conversion process is as follows: Calculate the value of x: Calculate the value of y: Calculate the value of z:

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