Bridge deformation monitoring method and system based on three-dimensional laser scanning

Abstract

The invention relates to the technical field of bridge detection, in particular to a bridge deformation monitoring method and system based on three-dimensional laser scanning, and the system comprises a processor, a plurality of first infrared targets arranged on a bridge girder, and a plurality of second infrared targets vertically arranged along a bridge cable bent tower. The bridge cable tower is provided with a first three-dimensional laser scanner which is matched with the first infrared target to carry out deformation detection on a bridge girder, the bridge girder is provided with a second three-dimensional laser scanner which is matched with the second infrared target to carry out deformation detection on the bridge cable tower, and the device further comprises an adjusting mechanism. The first three-dimensional laser scanner and the second three-dimensional laser scanner are installed on the cable bent tower and the main beam through the adjusting mechanism, and when the processor detects that the cable bent tower and / or the main beam are / is deformed, the processor controls the adjusting mechanism to conduct adjustment so that the first three-dimensional laser scanner and / or the second three-dimensional laser scanner can be kept at the initial position. The deformation monitoring accuracy of the main beam and the cable bent tower of the stay cable bridge can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge detection, and particularly relates to a method and system for bridge deformation monitoring based on three-dimensional laser scanning. Background Art

[0002] As a cable-stayed system, a cable-stayed bridge has a greater spanning capacity than a girder bridge and is the most important bridge type for long-span bridges. A cable-stayed bridge is composed of many steel cables directly connected to the cable tower, and the cable-stayed bridge mainly consists of a cable tower, a main girder, and cable stays. Whether during the bridge construction process or the daily maintenance of the bridge, the deformation monitoring of the cable-stayed bridge is very important.

[0003] Currently, it is a relatively common detection method to detect bridge deformation through three-dimensional laser scanning technology. The principle is to respectively set a plurality of infrared targets on the main girder and the cable tower, and then set three-dimensional laser scanners on the cable tower and the main girder. Through the cooperation of the corresponding three-dimensional laser scanners and infrared targets, the point cloud information of the main girder and the cable tower is obtained, so as to respectively detect the deformation conditions of the main girder and the cable tower of the cable-stayed bridge. However, the disadvantage of the above detection method is that the three-dimensional laser scanner is fixed on the cable tower and the main girder, and its position cannot be adjusted after installation. If it is detected that the cable tower and / or the main girder is deformed, the three-dimensional laser scanner will also change slightly relative to its initial position during installation, which is likely to cause the distance and angle between the three-dimensional laser scanner and the corresponding infrared target to change due to the change in the position of the three-dimensional laser scanner. The position coordinates of the infrared target are calculated based on the distance and angle between the three-dimensional laser scanner and the infrared target. Compared with the situation where the position of the three-dimensional laser scanner remains unchanged and only the position change of the infrared target due to the deformation of the main girder and / or the cable tower is used to measure the point cloud coordinates reflecting the deformation of the main girder and / or the cable tower, the change in the position of the three-dimensional laser scanner (equivalent to the measurement source) is likely to cause the measured point cloud coordinates to be inaccurate, thereby reducing the accuracy of the detection result. Summary of the Invention

[0004] The present invention aims to provide a method and system for bridge deformation monitoring based on three-dimensional laser scanning to improve the accuracy of deformation monitoring of the main girder and the cable tower of a cable-stayed bridge.

[0005] A bridge deformation monitoring system based on 3D laser scanning, comprising a processor, a plurality of first infrared targets arranged on the main beam of the bridge, and a plurality of second infrared targets arranged vertically along the cable tower of the bridge. A first 3D laser scanner for detecting the deformation of the main beam of the bridge in cooperation with the first infrared target is provided on the cable tower of the bridge, and a second 3D laser scanner for detecting the deformation of the cable tower in cooperation with the second infrared target is provided on the main beam of the bridge. The system further includes an adjustment mechanism. Both the first 3D scanner and the second 3D laser scanner are installed on the cable tower and the main beam through the adjustment mechanism. When the processor detects that the cable tower and / or the main beam is deformed, the processor controls the adjustment mechanism to adjust so that the first 3D laser scanner and / or the second 3D laser scanner is maintained at the initial position.

[0006] The beneficial effects of the present invention are as follows: In the present invention, a first 3D laser scanner for detecting the deformation of the main beam of the bridge in cooperation with the first infrared target is provided on the cable tower of the bridge, so as to realize the deformation monitoring of the main beam. By providing a second 3D laser scanner for detecting the deformation of the cable tower in cooperation with the second infrared target on the main beam of the bridge, the deformation monitoring of the cable tower is realized.

[0007] When the main beam is deformed, the position of the second 3D laser scanner located on the main beam will change slightly. The second 3D laser scanner is adjusted from the current position back to the initial position through the adjustment mechanism, so as to ensure the accuracy of the position coordinates of each infrared target on the cable tower detected, thereby improving the accuracy of the cable tower deformation monitoring.

[0008] When the cable tower is deformed, the position of the first 3D laser scanner located on the cable tower will change slightly. The first 3D laser scanner is adjusted from the current position back to the initial position through the adjustment mechanism, so as to ensure the accuracy of the position coordinates of each infrared target on the main beam detected, thereby improving the accuracy of the main beam deformation monitoring.

[0009] A preferred embodiment of the present invention is that: Second infrared targets are provided on both sides of the first 3D laser scanner, and first infrared targets are provided on both sides of the second 3D laser scanner.

[0010] The beneficial effect is that: Second infrared targets are provided on both sides of the first 3D laser scanner in the present invention. Thus, the deformation conditions at the cable tower where the first 3D laser scanner is located can be detected more accurately and targeted through the multiple second infrared targets near both sides of the first 3D laser scanner. Then, based on the deformation conditions, the displacement of the first 3D laser scanner can be analyzed, and thus the action of the adjustment mechanism can be controlled targeted to adjust the position of the first 3D laser scanner, making the position adjustment of the first 3D laser scanner more accurate.

[0011] Second infrared targets are provided on both sides of the second 3D laser scanner. Thus, the deformation of the main girder where the second 3D laser scanner is located can be detected more accurately and specifically through multiple second infrared targets near both sides of the second 3D laser scanner. Then, the displacement of the second 3D laser scanner can be analyzed based on this deformation condition, and the action of the adjustment mechanism can be controlled accordingly to make the position adjustment of the second 3D laser scanner more accurate.

[0012] A preferred embodiment of the present invention is that: the processor pre-stores the initial position coordinates of the first 3D laser scanner and the second 3D laser scanner. When the processor detects that the cable tower and / or the main girder is deformed, the processor calculates the current position coordinates of the first 3D laser scanner and the second 3D laser scanner, and based on the current position coordinates and the initial position coordinates, controls the adjustment mechanism to drive the first 3D laser scanner and / or the second 3D laser scanner to reset from the current position to the initial position.

[0013] The beneficial effect is that: after the cable tower and / or the main girder is deformed, the positions of the first 3D laser scanner and the second 3D laser scanner installed on the cable tower and the main girder will shift compared with the initial positions. The processor calculates the distances that the first 3D laser scanner and / or the second 3D laser scanner should move horizontally and vertically towards the initial positions based on the initial position coordinates stored in the system and the current position coordinates, and then controls the adjustment mechanism to drive the first 3D laser scanner and / or the second 3D laser scanner to reset from the current position to the initial position, realizing precise fine-tuning of the positions of the first 3D laser scanner and the second 3D laser scanner.

[0014] A preferred embodiment of the present invention is that: the adjustment mechanisms of the first 3D laser scanner and the second 3D laser scanner are the same, and both include an installation surface distance adjustment structure and a position adjustment structure along the installation surface direction.

[0015] The beneficial effect is that: through the installation surface distance adjustment structure, the distance between the 3D laser scanner and the installation surface can be adjusted, and through the position adjustment structure along the installation surface direction, the position of the 3D laser scanner along the installation surface direction can be adjusted.

[0016] A preferred embodiment of the present invention is that: both the installation surface distance adjustment structure and the position adjustment structure along the installation surface direction adopt adjustment cylinders. The structure is simple, the installation is convenient, and the cost is low.

[0017] A preferred embodiment of the present invention is that: the directions in which the first 3D scanner and the second 3D laser scanner emit lasers towards the first infrared target and the second infrared target respectively are the same as the direction of the cable stay of the bridge.

[0018] The beneficial effects are as follows: Through this design of the present invention, through the cooperation of the first 3D scanner and the first infrared target, not only can the deformation of the main beam be detected, and through the cooperation of the second 3D laser scanner and the second infrared target, not only can the deformation of the cable tower be detected, but also if initially, the laser emitted by the first 3D scanner located on the cable tower can be received by the first infrared target located on the main beam, and the stay cable is not deformed initially, the first length of the stay cable when it is not deformed can be calculated by calculating the distance between the first 3D scanner and the reception of the first infrared target. Further, as a calibration method, the second length of the stay cable when it is not deformed can be calculated by calculating the distance between the second 3D scanner and the reception of the second infrared target. Combining the first length and the second length can accurately obtain the initial length of the stay cable. If the stay cable is deformed later, and if the deformation amplitude exceeds the preset threshold, it will cause the first infrared target not to receive the laser emitted by the first 3D scanner. As a verification means for whether the deformation amplitude of the stay cable exceeds the preset threshold, if the second infrared target also does not receive the laser emitted by the second 3D scanner, it verifies that the current deformation amplitude of the stay cable exceeds the threshold and an alarm prompt is required.

[0019] A bridge deformation monitoring method based on 3D laser scanning includes the following: The first 3D laser scanner emits lasers to a plurality of first infrared targets located on the bridge main beam to obtain the point cloud of the bridge main beam, and the second 3D laser scanner emits lasers to a plurality of second infrared targets located on the bridge cable tower to obtain the point cloud of the bridge cable tower; The processor determines whether there is deformation in the bridge main beam and the bridge cable tower respectively according to the point cloud of the bridge main beam and the point cloud of the bridge cable tower; If there is deformation in the bridge main beam, the processor issues an adjustment signal to control the adjustment mechanism to adjust the position of the first 3D laser scanner to keep the first 3D laser scanner at the initial position; if there is deformation in the bridge cable tower, the processor issues an adjustment signal to control the adjustment mechanism to adjust the position of the second 3D laser scanner to keep the second 3D laser scanner at the initial position.

[0020] The bridge deformation monitoring method based on 3D laser scanning further includes the following: When the processor detects that the cable tower and / or the main beam is deformed, the processor calculates the current position coordinates of the first 3D laser scanner and the second 3D laser scanner, and calculates the distance to be adjusted based on the current position coordinates and the initial position coordinates, and controls the adjustment mechanism to drive the first 3D laser scanner and / or the second 3D laser scanner to reset from the current position to the initial position.

[0021] When the main beam deforms in the method of the present invention, the position of the second 3D laser scanner on the main beam will change slightly. The second 3D laser scanner is adjusted from the current position back to the initial position through the adjustment mechanism, so as to ensure the accuracy of the position coordinates of each infrared target on the pylon, thereby improving the accuracy of pylon deformation monitoring.

[0022] When the pylon deforms, the position of the first 3D laser scanner on the pylon will change slightly. The first 3D laser scanner is adjusted from the current position back to the initial position through the adjustment mechanism, so as to ensure the accuracy of the position coordinates of each infrared target on the main beam, thereby improving the accuracy of main beam deformation monitoring. Brief Description of the Drawings

[0023] Figure 1 It is a schematic diagram of an embodiment of the bridge deformation monitoring system based on 3D laser scanning of the present invention.

[0024] Figure 2 It is a schematic diagram of the installation of infrared targets and 3D laser scanners in the bridge deformation monitoring system based on 3D laser scanning of the present invention.

[0025] Figure 3 It is a schematic diagram of the structure of the adjustment mechanism in the embodiment of the present invention. Detailed Embodiment

[0026] The following describes the preferred embodiments of the present invention with reference to the drawings. It should be understood that the described preferred embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0027] Terms such as "first" and "second" in the specification, claims, and embodiments of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence.

[0028] The present invention will be further described in detail below through preferred specific embodiments: The reference numerals in the drawings of the specification include: main beam 1, pylon 2, first infrared target 3, first 3D laser scanner 4, second infrared target 5, second 3D laser scanner 6, stay cable 7, vertical adjustment cylinder 8, support plate 9, horizontal adjustment cylinder 10, mounting plate 11, mounting seat 12, elastic block 13.

[0029] As shown in the attached Figure 1 、 Figure 2The following discloses a bridge deformation monitoring system based on three-dimensional laser scanning, which includes a processor, a plurality of first infrared targets arranged on the bridge main girder, and a plurality of second infrared targets arranged vertically along the bridge pylon. A first three-dimensional laser scanner for detecting the deformation of the bridge main girder in cooperation with the first infrared target is provided on the bridge pylon, and a second three-dimensional laser scanner for detecting the deformation of the bridge pylon in cooperation with the second infrared target is provided on the bridge main girder.

[0030] In this embodiment, second infrared targets are provided on both sides of the first three-dimensional laser scanner, and first infrared targets are provided on both sides of the second three-dimensional laser scanner. The directions in which the first three-dimensional scanner and the second three-dimensional laser scanner emit laser beams towards the first infrared target and the second infrared target respectively are the same as the direction of the bridge stay cables. Specifically, a first infrared target is provided on one side of each stay cable at the main girder end, and a second three-dimensional laser scanner is provided on the other side. A first three-dimensional laser scanner is provided on one side of each stay cable at the pylon end, and a second infrared target is provided on the other side. In this way, not only can the direction of the laser beam emitted by the three-dimensional laser scanner be the same as the axial direction of the stay cable, but also it can be ensured that second infrared targets are arranged on both sides of each first three-dimensional laser scanner, and first infrared targets are arranged on both sides of each second three-dimensional laser scanner, so as to more accurately detect the deformation at the positions where the first three-dimensional laser scanner and the second three-dimensional laser scanner are located, and thus achieve precise adjustment.

[0031] In this embodiment, both the first three-dimensional scanner and the second three-dimensional laser scanner are installed on the pylon and the main girder through an adjustment mechanism. When the processor detects that the pylon and / or the main girder is deformed, the processor controls the adjustment mechanism to make adjustments so that the first three-dimensional laser scanner and / or the second three-dimensional laser scanner remain in the initial position. The adjustment mechanisms of the first three-dimensional laser scanner and the second three-dimensional laser scanner are the same, and both include an installation surface distance adjustment structure and a position adjustment structure along the installation surface direction. Both the installation surface distance adjustment structure and the position adjustment structure along the installation surface direction adopt adjustment cylinders. As shown in the appendix Figure 3The figure shows a schematic diagram of the adjustment mechanism of this embodiment, including a mounting base 12 with a hollow interior. It also includes a vertical adjustment cylinder 8, the cylinder body of the vertical adjustment cylinder 8 is located inside the mounting base 12, a through hole is opened at the top of the mounting base 12, and the piston rod of the vertical adjustment cylinder 8 passes through the through hole and extends outside the mounting base 12. A support plate 9 is fixed to the upper end of the piston rod of the vertical adjustment cylinder 8. A horizontal adjustment cylinder 10 is provided on the support plate 9. An installation plate 11 is provided at the end of the piston rod of the horizontal adjustment cylinder 10. A three-dimensional laser scanner is installed on the upper part of the installation plate 11. In this embodiment, two elastic blocks 13 are arranged side by side at the top of the mounting base 12, and the bottom of the installation plate 11 is in contact with the top of the elastic blocks 13. Since the elastic blocks 13 are elastic, their tops will always abut against the bottom of the installation plate 11 as the installation plate 11 moves up and down and will not separate from the installation plate 11. Therefore, the elastic blocks 13 always play a role in stabilizing and guiding the installation plate 11 when it moves horizontally.

[0032] The processor has previously stored the initial position coordinates of the first three-dimensional laser scanner and the second three-dimensional laser scanner. When the processor detects that the pylon and / or the main girder are deformed, the processor calculates the current position coordinates of the first three-dimensional laser scanner and the second three-dimensional laser scanner, and based on the current position coordinates and the initial position coordinates, controls the adjustment mechanism to drive the first three-dimensional laser scanner and / or the second three-dimensional laser scanner to reset from the current position to the initial position. In this embodiment, the initial position coordinates of the first three-dimensional laser scanner and the second three-dimensional laser scanner are set as the origin coordinates, that is, both are (0, 0, 0). By the first three-dimensional laser scanner emitting laser and returning, the position coordinates of each first infrared target can be calculated. Based on the position coordinates of multiple first infrared targets, connecting lines in space can analyze the deformation conditions of the main girder, including the deformation amplitude of each position segment of the main girder. Based on the deformation amplitude of each position segment, the displacement amounts of the second three-dimensional laser scanner in the horizontal and vertical directions at the corresponding positions can be calculated. Based on the calculated displacement amounts, the processor sends a control signal to the adjustment mechanism to control the adjustment mechanism to drive the second three-dimensional laser scanner to move the corresponding horizontal displacement along the direction same as the installation surface through the horizontal adjustment cylinder, and drive the second three-dimensional laser scanner to move the corresponding vertical displacement along the direction perpendicular to the installation surface through the vertical adjustment cylinder, so that the second three-dimensional laser scanner returns to the initial position. The position adjustment principle of the first three-dimensional laser scanner is the same as that of the second three-dimensional laser scanner.

[0033] This embodiment also discloses a method for monitoring bridge deformation based on three-dimensional laser scanning, including the following content: The first 3D laser scanner emits lasers towards multiple first infrared targets located on the bridge girder, thereby obtaining the bridge girder point cloud. The second 3D laser scanner emits lasers towards multiple second infrared targets located on the bridge tower, thereby obtaining the bridge tower point cloud; The processor determines whether the bridge girder and the bridge tower are deformed respectively according to the bridge girder point cloud and the bridge tower point cloud; If the bridge girder is deformed, the processor issues an adjustment signal to control the adjustment mechanism to adjust the position of the first 3D laser scanner so that the first 3D laser scanner remains at the initial position. If the bridge tower is deformed, the processor issues an adjustment signal to control the adjustment mechanism to adjust the position of the second 3D laser scanner so that the second 3D laser scanner remains at the initial position.

[0034] After the processor detects that the tower and / or the girder is deformed, the processor calculates the current position coordinates of the first 3D laser scanner and the second 3D laser scanner, and calculates the distance to be adjusted based on the current position coordinates and the initial position coordinates, and controls the adjustment mechanism to drive the first 3D laser scanner and / or the second 3D laser scanner to reset from the current position to the initial position.

[0035] The preferred embodiments of the present application have been described in detail above in conjunction with the accompanying drawings. Typical well-known structures and common general knowledge technologies in the preferred embodiments are not described in detail here. Those of ordinary skill in the art can, under the inspiration given by this embodiment, combine their own abilities to complete and implement the technical solution of the present invention. Some typical well-known structures, well-known methods or common general knowledge technologies should not become an obstacle for those of ordinary skill in the art to implement the present application.

[0036] The scope of protection required by the present application shall be subject to the content of its claims, and the content recorded in the invention content, specific implementation manners and the drawings of the description is used to interpret the claims.

[0037] Within the scope of the technical concept of the present application, several variations can also be made to the specific implementation manners of the present application, and these modified specific implementation manners should also be regarded as within the scope of protection of the present application.

Claims

1. A bridge deformation monitoring system based on 3D laser scanning, comprising a processor, a plurality of first infrared targets arranged on the main beam of the bridge, and a plurality of second infrared targets arranged vertically along the bridge pylon. A first 3D laser scanner for detecting the deformation of the main beam of the bridge in cooperation with the first infrared targets is provided on the bridge pylon, and a second 3D laser scanner for detecting the deformation of the bridge pylon in cooperation with the second infrared targets is provided on the main beam of the bridge, characterized in that: It further includes an adjustment mechanism. The first 3D scanner and the second 3D laser scanner are both installed on the cable tower and the main girder through the adjustment mechanism. When the processor detects that the cable tower and / or the main girder is deformed, the processor controls the adjustment mechanism to adjust so that the first 3D laser scanner and / or the second 3D laser scanner remains in the initial position.

2. The bridge deformation monitoring system based on 3D laser scanning according to claim 1, wherein: Second infrared targets are provided on both sides of the first 3D laser scanner, and first infrared targets are provided on both sides of the second 3D laser scanner.

3. The bridge deformation monitoring system based on three-dimensional laser scanning according to claim 1, characterized in that: The processor has previously stored the initial position coordinates of the first 3D laser scanner and the second 3D laser scanner. After the processor detects that the cable tower and / or the main girder is deformed, the processor calculates the current position coordinates of the first 3D laser scanner and the second 3D laser scanner, and based on the current position coordinates and the initial position coordinates, controls the adjustment mechanism to drive the first 3D laser scanner and / or the second 3D laser scanner to reset from the current position to the initial position.

4. The bridge deformation monitoring system based on 3D laser scanning according to claim 1, characterized in that: The adjustment mechanisms of the first 3D laser scanner and the second 3D laser scanner are the same, and both include an installation surface distance adjustment structure and a position adjustment structure along the installation surface direction.

5. The bridge deformation monitoring system based on three-dimensional laser scanning according to claim 4, characterized in that: Both the installation surface distance adjustment structure and the position adjustment structure along the installation surface direction adopt adjustment cylinders.

6. The bridge deformation monitoring system based on 3D laser scanning according to claim 1, characterized in that: The directions in which the first 3D scanner and the second 3D laser scanner respectively emit lasers towards the first infrared target and the second infrared target are the same as the direction of the cable stay of the bridge.

7. A bridge deformation monitoring method based on three-dimensional laser scanning, characterized in that, It includes the following: The first 3D laser scanner emits lasers towards a plurality of first infrared targets located on the bridge main girder, thereby obtaining the bridge main girder point cloud, and the second 3D laser scanner emits lasers towards a plurality of second infrared targets located on the bridge cable tower, thereby obtaining the bridge cable tower point cloud; The processor respectively determines whether the bridge main girder and the bridge cable tower are deformed according to the bridge main girder point cloud and the bridge cable tower point cloud; If the bridge main girder is deformed, the processor issues an adjustment signal to control the adjustment mechanism to adjust the position of the first 3D laser scanner so that the first 3D laser scanner remains in the initial position; if the bridge cable tower is deformed, the processor issues an adjustment signal to control the adjustment mechanism to adjust the position of the second 3D laser scanner so that the second 3D laser scanner remains in the initial position.

8. The method for bridge deformation monitoring based on 3D laser scanning according to claim 7, characterized in that: After the processor detects that the cable tower and / or the main girder is deformed, the processor calculates the current position coordinates of the first 3D laser scanner and the second 3D laser scanner, and calculates the distance to be adjusted based on the current position coordinates and the initial position coordinates, and controls the adjustment mechanism to drive the first 3D laser scanner and / or the second 3D laser scanner to reset from the current position to the initial position.

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