Precise assembling method for bridge girder sections

Abstract

The invention relates to a bridge girder section precise assembling method, and belongs to the technical field of bridge construction.The bridge girder section precise assembling method comprises the steps that spherical prisms are arranged at the ends of the splicing ends of girder section rods, the ends of the splicing ends are scanned through a scanner, a total station is arranged on erected girder sections, and the total station is used for scanning the splicing ends of the girder section rods; then, reverse modeling at the splicing ends of the girder segments is established, the bridge girder erection machine is controlled to adjust the poses and the displacement of the girder segments, bolt hole groups of the unerected girder segments and the erected girder segments are subjected to registration butt joint, precise splicing is achieved, and the steps are repeated to enable the next unerected girder segments to continue to be spliced; according to the invention, the spherical prism is installed at the end of the girder section of the bridge to serve as a positioning mark, the handheld three-dimensional scanner is used to scan the end in detail, coordinates of key feature points are accurately extracted by using an intelligent algorithm, real-time monitoring is carried out through the total station, monitoring data are processed through the intelligent algorithm, and the optimal butt joint pose of the girder section is automatically calculated. And the truss section assembly precision and efficiency are improved.

Description

Technical Field

[0001] The present application relates to the technical field of bridge construction, and in particular to a method for accurately assembling bridge truss segments. Background Art

[0002] In the field of modern bridge construction, especially in the construction of kilometer-level long-span railway bridges, the precise assembly technology of bridge truss segments is particularly critical. Long-span bridges are widely favored for their beautiful lines, strong spanning capacity and efficient structural performance. However, with the increasing complexity of bridge design and the improvement of construction precision requirements, how to ensure the precise docking of bridge truss segments during construction has become an important challenge to ensure the overall project quality, safety and timely completion.

[0003] Traditional bridge truss segment assembly methods rely on manual measurement and experience-based operations, using total stations, levels and other traditional measurement tools for positioning and docking. This method may be able to meet basic needs when dealing with simple structures, but when faced with complex long-span bridge projects, problems such as human errors, low operating efficiency and poor adaptability to complex spatial relationships gradually become prominent, which directly affects construction accuracy and project progress, and increases project costs.

[0004] The current method of scanning the truss segment by using a base station scanner has the problem of insufficient progress. Although this scanning method can cover a large measurement range, when it is necessary to capture small details such as the ends of rods or complex geometric shapes, its limited spatial resolution and the accumulation of long-distance measurement errors may lead to the loss of key information and deviations in measurement results. Especially on bridge trusses with complex structures and multiple mutually shielding parts, the poor adaptability of the base station scanner further affects the overall measurement quality. Therefore, although the base station scanner has its convenience in some scenarios, its disadvantage of insufficient accuracy is obvious in projects that pursue high-precision bridge truss segment assembly, and a higher-precision measurement solution is needed to meet engineering needs. Summary of the invention

[0005] The embodiment of the present application provides a method for accurately assembling bridge truss segments to solve the problem of insufficient precision in assembling existing steel trusses in the related art.

[0006] The present application provides a method for accurately assembling bridge truss segments, comprising the following steps:

[0007] A spherical prism is arranged on the joint end of each truss rod;

[0008] Scan the end of the splicing end with a scanner to extract the coordinates of the bolt hole group and the spherical prism at the splicing end;

[0009] A total station is set up on the erected truss section so that the total station can measure the spherical prism on the joint end of the erected truss section and the unerection truss section, and then a reverse modeling is established at the joint end of the truss section to determine the spatial position of the truss section rod end;

[0010] According to the data results of reverse modeling, the bolt hole groups of the erected truss section and the bolt hole groups of the unerection truss section are matched and registered one by one;

[0011] Calculate the data of translation and rotation matrix generated by the matching and registration of each end of the truss segment, and control the bridge erection machine to adjust the truss segment posture and displacement, so that the bolt hole groups of the unerected truss segment and the erected truss segment are aligned and docked to achieve precise assembly;

[0012] Repeat the above steps to continue splicing the next unerection truss segment.

[0013] In some embodiments, the specific process of setting the spherical prism at the joint end of each truss rod is as follows:

[0014] Three spherical prisms are arranged on any end of the spliced ​​end of each truss segment rod, the spherical prism located at the lower chord rod is installed on the top of the end, and the spherical prism located at the upper chord rod is installed at the bottom of the end.

[0015] In some embodiments, the specific process of extracting the coordinates of the bolt hole group and the spherical prism at the splicing end is:

[0016] The RANSAC algorithm is used to extract the coordinates of the center of the bolt hole and the center of the prism at the splicing end.

[0017] In some embodiments, the specific process of extracting the coordinates of the center of the bolt hole and the center of the spherical prism using the RANSAC algorithm is as follows:

[0018] Preliminary screening of point cloud data through a straight-through filter to exclude irrelevant noise points;

[0019] Simplify the point cloud through voxel downsampling method to reduce the computational burden while retaining key geometric information;

[0020] Use the RANSAC algorithm to identify bolt holes and prisms in the point cloud;

[0021] Finally, the least square method is used to perform circular or spherical geometric fitting to accurately determine the center coordinates of the bolt hole and the spherical prism.

[0022] In some embodiments, a total station is arranged on the erected truss segment so that the total station can measure the spherical prism at the splicing end of the erected truss segment and the unerected truss segment, and then a reverse modeling is established at the splicing end of the truss segment to determine the specific process of the spatial position of the truss segment rod end:

[0023] A total station is set on the erected truss section so that the total station can automatically measure all the spherical prisms on the joint ends of the erected truss section and the unerection truss section;

[0024] The coordinates measured by the total station are used as the target point cloud, and the truss rod ends measured in the beam field are used as the source point cloud. The algorithm is used to use the coordinates of the center of the spherical prism as the common point to determine the position of the truss rod ends in space, complete the reverse modeling of the truss splicing end, and accurately determine the spatial position of the truss rod ends.

[0025] In some embodiments, an algorithm is used to determine the position of the truss segment rod end in space using the coordinates of the center of the spherical prism as a common point, and reverse modeling is completed at the truss segment splicing end. The specific process of accurately determining the spatial position of the truss segment rod end is as follows:

[0026] The Umeyama algorithm is used to compare and analyze the source point cloud and the target point cloud, and the coordinates of the center of the spherical prism are used as the common point connecting the two.

[0027] The spatial transformation matrix of the source point cloud and the target point cloud is obtained, and the matrix is ​​applied to the source point cloud to complete the reverse modeling and accurately determine the spatial position of the end of the truss segment.

[0028] In some embodiments, according to the data results of the reverse modeling, the specific process of matching and aligning the bolt hole groups of the erected truss sections with the bolt hole groups of the unerection truss sections is as follows:

[0029] Set the ends of the trussed sections A1, A2, A3 and A4, and set the ends of the untrussed sections B5, B6, B7 and B8;

[0030] Through the Umeyama algorithm, it can be known that the matching of the ends of the erected truss segments and the unerected truss segments is A1 and B5, A2 and B6, A3 and B7, and A4 and B8.

[0031] In some embodiments, the specific process of calculating the translation and rotation matrix data generated by the matching and registration of the ends of the truss segments and the docking, controlling the bridge erection machine to adjust the truss segment posture and displacement, and making the bolt hole groups of the unerected truss segments and the erected truss segments aligned and docked to achieve precise assembly is as follows:

[0032] Automatically calculate the translation and rotation matrix data required for each end registration;

[0033] The optimal rotation matrix and translation vector are calculated by minimizing the average distance from the source point cloud to the target point cloud, and then the minimum workload of each end moving to the corresponding end of the truss segment is calculated so far;

[0034] By inputting the calculated translation and rotation matrices into the bridge-building machine, the bridge-building machine is controlled to adjust the position and displacement of the truss segments to achieve precise assembly.

[0035] In some embodiments, the specific process of repeating the above steps to continue splicing the next unassembled truss segment is:

[0036] After the initial assembly is completed, the space of the ends of the remaining truss segments changes, and the monitoring, registration and posture adjustment are repeated for the remaining unassembled ends;

[0037] Intelligent algorithms are used based on new real-time monitoring data until all ends are precisely docked and assembled to ensure the accuracy and stability of the bridge's overall structure.

[0038] In some embodiments, before the truss segments are assembled into truss segments, a prompt mark is set around the spherical prism, and after the assembly is completed, it is determined that the end of each truss segment is provided with a spherical prism.

[0039] The beneficial effects of the technical solution provided by this application include:

[0040] The spherical prism can be used to make the ends of the truss segment rods joints a common point. The total station can be used to automatically measure the joint positions of the unerected truss segments and the erected truss segments. Then, the algorithm is used to determine the positions of the ends of the truss segment rods in space, so that the reverse modeling of the truss segment splicing can be obtained. Then, the bolt hole groups of the unerected truss segments and the erected truss segments are aligned. The algorithm is then used to calculate the translation and rotation matrix required for the unerected truss segments and the erected truss segments when the bolt hole groups need to be aligned, and the position with the minimum movement is found. The truss segment posture is adjusted, and the bolt hole groups of the unerected truss segments and the erected truss segments are aligned for the initial assembly.

[0041] The preliminary coordinates of the spliced ​​truss rods can be automatically measured through spherical prisms, bolt hole groups, three-dimensional scanning and total stations. The coordinates of the two spliced ​​truss rods can then be accurately calculated again using algorithms, and the splicing coordinates between the spliced ​​ends of the two truss rods can be determined again, thereby improving accuracy and avoiding the poor adaptability of base station scanners that affects the overall measurement quality on bridge trusses with complex structures and multiple mutually obstructed parts caused by scanning only with scanners.

[0042] By installing spherical prisms as positioning marks at the ends of bridge truss segments, using a handheld 3D scanner to scan the ends in detail, and using an intelligent algorithm to accurately extract the coordinates of key feature points, real-time monitoring is performed through a total station, and the monitoring data is processed through an intelligent algorithm to automatically calculate the optimal docking position of the truss segments, thereby improving the accuracy and efficiency of truss segment assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 Flowchart provided for the embodiment of the present application;

[0045] Figure 2 A schematic diagram of the structure of a spherical prism provided in an embodiment of the present application;

[0046] Figure 3 A schematic diagram of the connection between the unerection truss section and the erection truss section provided in the embodiment of the present application.

[0047] 1. Truss section has been erected; 2. Truss section has not been erected; 3. Spherical prism. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0049] The embodiment of the present application provides a method for accurately assembling bridge truss segments, which can solve the problem of insufficient precision in the existing assembly of steel trusses.

[0050] See also Figure 1-3 As shown, the embodiment of the present application provides a method for accurately assembling bridge truss segments, comprising the following steps:

[0051] Step 1, arranging a spherical prism 3 on the joint end of each truss segment rod;

[0052] Step 2, scanning the end of the splicing end by a scanner to extract the coordinates of the bolt hole group of the splicing end and the spherical prism 3;

[0053] Step 3, a total station is set on the erected truss segment 1, so that the total station can measure the spherical prism 3 on the splicing end of the erected truss segment 1 and the unerected truss segment 2, and then a reverse modeling is established at the splicing end of the truss segment to determine the spatial position of the truss segment rod end;

[0054] Step 4: According to the data results of reverse modeling, the bolt hole groups of the erected truss segment 1 and the bolt hole groups of the unerection truss segment 2 are matched and registered one by one;

[0055] Step 5: Calculate the data of the translation and rotation matrix generated by the matching and registration of the ends of the truss segments, and control the bridge erection machine to adjust the truss segment posture and displacement, so that the bolt hole groups of the unerected truss segment 2 and the erected truss segment 1 are aligned and docked, so as to achieve accurate assembly;

[0056] Step 6: Repeat the above steps to continue splicing the next unerection truss section 2.

[0057] When it is necessary to assemble truss segments to form truss segments, firstly, three spherical prisms 3 are set at both ends of each truss segment rod as positioning prisms, and the positions of the three spherical prisms 3 cannot be located on the same horizontal and vertical lines. Then, the ends of the truss segment rods are scanned by a scanner to extract the bolt hole group and the coordinates of the spherical prisms 3 at the spliced ​​ends of the truss segment rods. Then, a total station is set on the erected truss segment 1. The position of the total station can measure all the spherical prisms 3 on the erected truss segment 1 and the unerected truss segment 2. Here, the position where the erected truss segment 1 is used to construct the bridge deck is preferably selected. Because the erected truss segment 1 is a fixed truss segment, the total station is set on the erected truss segment 1 to make the total station more stable and reduce shaking and deviation, thereby improving measurement accuracy.

[0058] The positions of the unerected truss section 2 and the erected truss section 1 can be automatically measured by the total station, and the coordinates measured by the total station are used as the target point cloud, and the ends of the rods measured in the beam field are used as the source point cloud. The intelligent algorithm is used to take the coordinates of the center of the spherical prism 3 as the common point to determine the position of the ends of the truss rods in space, complete the reverse modeling of the truss interface, and accurately determine the spatial position of the rod ends.

[0059] Then, according to the results of reverse modeling, the bolt hole groups of the erected truss segment 1 can be matched and aligned one by one with the bolt hole groups of the unerected truss segment 2, and the translation and rotation matrices required for the end alignment of the unerected truss segment 2 and the erected truss segment 1 can be automatically calculated. Taking the end with the smallest working movement as the reference, the calculated translation and rotation matrices are input into the bridge-erecting machine to control the bridge-erecting machine to adjust the truss segment posture and displacement, so that the bolt hole groups of the unerected truss segment 2 and the erected truss segment 1 can be accurately matched and docked.

[0060] After the initial assembly is completed, the end space of the remaining truss segments changes, and the remaining un-jointed truss segments continue to be assembled. Each joint assembly requires re-detection, alignment and posture adjustment, and the assembly strategy is iteratively optimized according to the new real-time monitoring data through the algorithm until the ends of all truss segments are accurately joined.

[0061] In some optional embodiments, see Figure 1-3 As shown, in the bridge truss segment precise assembly method, the specific process of step 1, setting the spherical prism 3 at the splicing end of each truss segment rod is:

[0062] Step 101, three spherical prisms 3 are arranged on any end of the spliced ​​end of each truss segment rod, the spherical prism 3 located at the lower chord rod is installed on the top of the end, and the spherical prism 3 located at the upper chord rod is installed on the bottom of the end.

[0063] In this embodiment, the spherical prism 3 is firstly welded to the end of the truss rod with the base. The spherical prism 3 cannot be located in a horizontal horizontal line, but should be placed in a scattered manner. Then, the end is scanned by a handheld three-dimensional laser scanner. The spacing between each coding point is within 15 cm and cannot be arranged regularly.

[0064] In some optional embodiments, see Figure 1-3 As shown, in the bridge truss segment precise assembly method, the specific process of step 2, extracting the coordinates of the splicing end bolt hole group and the spherical prism 3 is:

[0065] Step 202: Use the RANSAC algorithm to extract the coordinates of the center of the bolt hole at the splicing end and the coordinates of the center of the prism

[0066] In this embodiment, the specific process of step 202, using the RANSAC algorithm to extract the coordinates of the center of the bolt hole and the center of the spherical prism 3, is as follows:

[0067] Step 2021: Preliminarily filter the point cloud data through a straight-through filter to eliminate irrelevant noise points and improve data quality;

[0068] Step 2022, simplifying the point cloud by voxel downsampling method, reducing the computational burden while retaining key geometric information;

[0069] Step 2023, using the RANSAC algorithm to identify bolt holes and prisms in the point cloud;

[0070] Step 2024: Finally, the least square method is applied to perform circular or spherical geometric fitting to accurately determine the center coordinates of the bolt hole and the spherical prism 3.

[0071] In some optional embodiments, see Figure 1-3 As shown, in the bridge truss segment precise assembly method, step 3, a total station is set on the erected truss segment 1, so that the total station can measure the spherical prism 3 on the splicing end of the erected truss segment 1 and the unerected truss segment 2, and then the reverse modeling of the truss segment splicing end is established to determine the specific process of the spatial position of the truss segment rod end:

[0072] Step 301, a total station is arranged on the erected truss segment 1, so that the total station can automatically measure all the spherical prisms 3 on the splicing ends of the erected truss segment 1 and the unerection truss segment 2;

[0073] Step 302: take the coordinates measured by the total station as the target point cloud, and the ends of the truss rods measured at the beam field as the source point cloud. Use the algorithm to take the coordinates of the center of the spherical prism 3 as the common point to determine the position of the ends of the truss rods in space, complete the reverse modeling at the splicing end of the truss, and accurately determine the spatial position of the ends of the truss rods.

[0074] In this embodiment, step 302, using an algorithm to determine the position of the truss segment rod end in space with the coordinates of the center of the spherical prism 3 as a common point, completing the reverse modeling of the truss segment splicing end, and accurately determining the specific process of the spatial position of the truss segment rod end is:

[0075] Step 3021: Use the Umeyama algorithm to compare and analyze the source point cloud and the target point cloud, and use the coordinates of the center of the spherical prism 3 as the common point connecting the two.

[0076] Step 302: Obtain the spatial transformation matrix of the source point cloud and the target point cloud, apply the matrix to the source point cloud, complete the reverse modeling, and accurately determine the spatial position of the end of the truss segment.

[0077] In some optional embodiments, see Figure 1-3 As shown, in the bridge truss segment precise assembly method, the specific process of step 4, according to the data results of reverse modeling, making the bolt hole group of the erected truss segment 1 and the bolt hole group of the unerection truss segment 2 correspond to each other one by one is:

[0078] Step 401, setting the ends A1, A2, A3 and A4 of the erected truss segment 1, and setting the ends B5, B6, B7 and B8 of the unerection truss segment 2;

[0079] Step 402: Through the Umeyama algorithm, it can be known that the end matching of the erected truss segment 1 and the unerected truss segment 2 is A1 matches B5, A2 matches B6, A3 matches B7, and A4 matches B8.

[0080] In some optional embodiments, see Figure 1-3 As shown, in the bridge truss segment precise assembly method, step 5, calculates the data of the translation and rotation matrix generated by the matching and registration of each end of the truss segment rod, controls the bridge erection machine to adjust the truss segment posture and displacement, and makes the bolt hole groups of the unerected truss segment 2 and the erected truss segment 1 align and dock, and the specific process of achieving precise assembly is as follows:

[0081] Step 501: Automatically calculate the translation and rotation matrix data required for the registration of each terminal.

[0082] Step 502, calculating the best rotation matrix and translation vector by minimizing the average distance from the source point cloud to the target point cloud, and then calculating the minimum workload of each end moving to the corresponding truss segment end so far;

[0083] Step 503: By inputting the calculated translation and rotation matrices into the bridge-building machine, the bridge-building machine is controlled to adjust the posture and displacement of the truss segments to achieve precise assembly.

[0084] In this embodiment, the method for calculating the minimum workload is:

[0085] First, the translation workload is calculated by the translation vector, which is: t = [t x ,t y ,t z ];

[0086] Translation distance calculation: The translation distance is:

[0087] Then calculate the rotation angle: The rotation angle θ can be calculated from the rotation matrix using the Rodriguez rotation formula, Where TrR is the trajectory of the rotation matrix.

[0088] Then calculate the comprehensive working movement W: the working movement considering the translation distance and rotation angle: W = W 1 D+W 2 θ, where W 1 and W 2 It is a weighted coefficient and is adjusted according to the actual operation difficulty and construction requirements.

[0089] Then select the best tip: compare the W calculated for each tip, and select the tip with the smallest W value as the target for the first pose adjustment.

[0090] Finally, the rotation matrix and translation matrix instructions for the selected terminal pair are input into the bridge erection machine to complete the assembly of the terminal.

[0091] In some optional embodiments, see Figure 1-3 As shown, in the bridge truss segment precise assembly method, the specific process of step 6, repeating the above steps to continue to assemble the next unassembled truss segment 2 is:

[0092] Step 601: After the initial assembly is completed, the space of the ends of the remaining truss segments changes, and the monitoring, registration and posture adjustment are repeated for the remaining unassembled ends;

[0093] Step 602: Use intelligent algorithms based on new real-time monitoring data until all ends are accurately docked and assembled to ensure the accuracy and stability of the overall bridge structure.

[0094] The remaining unjointed ends of the truss segments are precisely aligned and their positions adjusted. Real-time monitoring is performed using a total station to collect the position data of the ends. The RANSAC algorithm is then used to extract key features from the point cloud. The ICP algorithm is then used to calculate the optimal translation and rotation matrices for each end, thereby evaluating and selecting the ends with the smallest working movement. The end positions are then finely adjusted using a bridge erection machine. This process is repeated until all ends are accurately joined, ensuring the accuracy and stability of the overall bridge structure.

[0095] In some optional embodiments, see Figure 1-3As shown, in the bridge truss segment precise assembly method, before the truss segment rods are assembled into truss segments, prompt marks are set around the spherical prisms 3, and after the assembly is completed, it is determined that the end of each truss segment is provided with a spherical prism 3.

[0096] During the stage of assembling the truss segments into truss segments, there is a risk of damaging the spherical prism 3 tooling due to the need for large-scale movement. In order to avoid this problem, eye-catching warning signs are applied around the spherical prism 3, which not only plays a protective role, but also enhances the vigilance of on-site staff to important measuring tooling. After the assembly is completed, careful inspection is carried out to ensure that the spherical prism 3 on the end of each truss segment is intact and in the correct position. This step is crucial for the subsequent precise measurement and truss segment docking work, ensuring the smooth progress of the entire process from preliminary assembly to final positioning, and providing a solid foundation for ensuring the precise assembly of bridge truss segments.

[0097] Working principle and process of this application:

[0098] When it is necessary to assemble truss segments to form truss segments, firstly, three spherical prisms 3 are set at both ends of each truss segment rod as positioning prisms, and the positions of the three spherical prisms 3 cannot be located on the same horizontal and vertical lines. Then, the ends of the truss segment rods are scanned by a scanner to extract the bolt hole group and the coordinates of the spherical prisms 3 at the spliced ​​ends of the truss segment rods. Then, a total station is set on the erected truss segment 1. The position of the total station can measure all the spherical prisms 3 on the erected truss segment 1 and the unerected truss segment 2. Here, the position where the erected truss segment 1 is used to construct the bridge deck is preferably selected. Because the erected truss segment 1 is a fixed truss segment, the total station is set on the erected truss segment 1 to make the total station more stable and reduce shaking and deviation, thereby improving measurement accuracy.

[0099] The positions of the unerected truss section 2 and the erected truss section 1 can be automatically measured by the total station, and the coordinates measured by the total station are used as the target point cloud, and the ends of the rods measured in the beam field are used as the source point cloud. The intelligent algorithm is used to take the coordinates of the center of the spherical prism 3 as the common point to determine the position of the ends of the truss rods in space, complete the reverse modeling of the truss interface, and accurately determine the spatial position of the rod ends.

[0100] Then, according to the results of reverse modeling, the bolt hole groups of the erected truss segment 1 can be matched and aligned one by one with the bolt hole groups of the unerected truss segment 2, and the translation and rotation matrices required for the end alignment of the unerected truss segment 2 and the erected truss segment 1 can be automatically calculated. Taking the end with the smallest working movement as the reference, the calculated translation and rotation matrices are input into the bridge-erecting machine to control the bridge-erecting machine to adjust the truss segment posture and displacement, so that the bolt hole groups of the unerected truss segment 2 and the erected truss segment 1 can be accurately matched and docked.

[0101] After the initial assembly is completed, the end space of the remaining truss segments changes, and the remaining un-jointed truss segments continue to be assembled. Each joint assembly requires re-detection, alignment and posture adjustment, and the assembly strategy is iteratively optimized according to the new real-time monitoring data through the algorithm until the ends of all truss segments are accurately joined.

[0102] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and 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 it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0103] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0104] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for accurately assembling bridge truss segments, characterized in that: include: A spherical prism (3) is arranged on the joint end of each truss rod; Scanning the end of the splicing end with a scanner to extract the coordinates of the bolt hole group and the spherical prism (3) of the splicing end; A total station is arranged on the erected truss section (1) so that the total station can measure the spherical prism (3) at the joint end of the erected truss section (1) and the unerection truss section (2), and then a reverse modeling is established at the joint end of the truss section to determine the spatial position of the truss section rod end; According to the data results of the reverse modeling, the bolt hole groups of the erected truss section (1) and the bolt hole groups of the unerection truss section (2) are matched and registered one by one; Calculate the data of the translation and rotation matrix generated by the matching and registration of the ends of the truss segments and then docking them, and control the bridge erection machine to adjust the truss segment posture and displacement, so that the bolt hole groups of the unerected truss segment (2) and the erected truss segment (1) are aligned and docked, thereby achieving accurate assembly; Repeat the above steps to continue splicing the next un-erection truss section (2).

2. The bridge truss segment precise assembly method according to claim 1, characterized in that: The specific process of arranging the spherical prism (3) at the joint ends of each truss segment rod is as follows: Three spherical prisms (3) are arranged on any end of the spliced ​​end of each truss segment rod, the spherical prism (3) located on the lower chord rod is installed on the top of the end, and the spherical prism (3) located on the upper chord rod is installed on the bottom of the end.

3. The bridge truss segment precise assembly method according to claim 1, characterized in that: The specific process of extracting the coordinates of the bolt hole group and the spherical prism (3) at the splicing end is as follows: The RANSAC algorithm is used to extract the coordinates of the center of the bolt hole and the center of the prism at the splicing end.

4. The bridge truss segment precise assembly method according to claim 3, characterized in that: The specific process of using the RANSAC algorithm to extract the coordinates of the center of the bolt hole and the center of the spherical prism (3) is as follows: Preliminary screening of point cloud data through a straight-through filter to exclude irrelevant noise points; Simplify the point cloud through voxel downsampling method to reduce the computational burden while retaining key geometric information; Use the RANSAC algorithm to identify bolt holes and prisms in the point cloud; Finally, the least square method is used to perform circular or spherical geometric fitting to accurately determine the center coordinates of the bolt hole and the spherical prism (3).

5. The bridge truss segment precise assembly method according to claim 1, characterized in that: A total station is set on the erected truss section (1) so that the total station can measure the spherical prism (3) at the splicing end of the erected truss section (1) and the unerected truss section (2), and then a reverse modeling is established at the splicing end of the truss section to determine the specific process of the spatial position of the truss section rod end: A total station is arranged on the erected truss section (1), so that the total station can automatically measure all the spherical prisms (3) on the spliced ​​ends of the erected truss section (1) and the unerection truss section (2); The coordinates measured by the total station are used as the target point cloud, and the ends of the truss segments measured at the beam field are used as the source point cloud. The algorithm is used to determine the position of the ends of the truss segments in space using the coordinates of the center of the spherical prism (3) as the common point, complete the reverse modeling of the truss segment splicing end, and accurately determine the spatial position of the ends of the truss segments.

6. The bridge truss segment precise assembly method according to claim 5, characterized in that: The algorithm is used to determine the position of the truss segment rod end in space with the coordinates of the center of the spherical prism (3) as the common point, and the reverse modeling of the truss segment splicing end is completed. The specific process of accurately determining the spatial position of the truss segment rod end is as follows: The Umeyama algorithm is used to compare and analyze the source point cloud and the target point cloud, and the coordinates of the center of the spherical prism (3) are used as the common point connecting the two. The spatial transformation matrix of the source point cloud and the target point cloud is obtained, and the matrix is ​​applied to the source point cloud to complete the reverse modeling and accurately determine the spatial position of the truss segment rod end.

7. The bridge truss segment precise assembly method according to claim 1, characterized in that: According to the data results of the reverse modeling, the specific process of matching and aligning the bolt hole groups of the erected truss section (1) with the bolt hole groups of the unerection truss section (2) is as follows: The ends A1, A2, A3 and A4 of the trussed section (1) are provided, and the ends B5, B6, B7 and B8 of the untrussed section (2) are provided; Through the Umeyama algorithm, it can be known that the end matching of the erected truss segment (1) and the unerection truss segment (2) is A1 matches B5, A2 matches B6, A3 matches B7, and A4 matches B8.

8. The bridge truss segment precise assembly method according to claim 7, characterized in that: The specific process of calculating the translation and rotation matrix data generated by the matching and registration of the ends of the truss segments and the docking, controlling the bridge erection machine to adjust the truss segment posture and displacement, so that the bolt hole groups of the unerected truss segment (2) and the erected truss segment (1) are aligned and docked, and realizing accurate assembly is as follows: Automatically calculate the translation and rotation matrix data required for each end registration; The optimal rotation matrix and translation vector are calculated by minimizing the average distance from the source point cloud to the target point cloud, and then the minimum workload of each end moving to the corresponding end of the truss segment is calculated so far; By inputting the calculated translation and rotation matrices into the bridge-building machine, the bridge-building machine is controlled to adjust the position and displacement of the truss segments to achieve precise assembly.

9. The bridge truss segment precise assembly method according to claim 1, characterized in that: The specific process of repeating the above steps to continue splicing the next unframed truss segment (2) is as follows: After the initial assembly is completed, the space of the ends of the remaining truss segments changes, and the monitoring, registration and posture adjustment are repeated for the remaining unassembled ends; Intelligent algorithms are used based on new real-time monitoring data until all ends are precisely docked and assembled to ensure the accuracy and stability of the bridge's overall structure.

10. The bridge truss segment precise assembly method according to claim 1, characterized in that: Before the truss segments are assembled into truss segments, a prompt mark is set around the spherical prism (3), and after the assembly is completed, it is determined that the end of each truss segment is provided with a spherical prism (3).

Images