Bridge bridge deck linear rapid measurement method and system based on multi-source data fusion

Abstract

The application discloses a kind of bridge bridge deck linear fast measurement methods based on multi-source data fusion, comprising: determining measurement area, with field control point as reference, complete equipment calibration;Complete bridge deck structure relative coordinate point cloud data, absolute coordinate and elevation data acquisition;With field control point as reference, coordinate is unified and constructs the three-dimensional model of bridge deck structure under absolute coordinate system;Including point cloud slice analysis, Gaussian filter residual method, elevation difference calculation and curve fitting, the method is extracted including the elevation of bridge deck and concrete pedestal, flatness, overall linear curve in parameter, the thickness and distribution characteristics of concrete between each structure layer are calculated by comparing layer point cloud, then deviation analysis is carried out to the extracted parameter in combination with design standard;According to the analysis result, output adjustment suggestion in concrete pouring stage, output positioning correction parameter in track slab installation stage.The efficient collection of bridge deck linear and related parameters is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge engineering measurement and ballastless track construction control, and more particularly to a bridge deck linear rapid measurement method and system based on multi-source data fusion. BACKGROUND

[0002] In the construction and operation process of long-span bridges, the accurate measurement and dynamic control of bridge deck linear (covering core parameters such as elevation, flatness, longitudinal slope, and transverse curvature) are key links to ensure the long-term safety of bridge structures and the comfort of train operation. In high-precision construction scenarios such as ballastless track laying, the linear measurement accuracy directly determines the track laying quality and post-operation stability. The traditional bridge deck linear measurement method widely used in the current industry takes total station and electronic level as the core equipment and adopts manual single-point measurement mode, which exposes many unavoidable shortcomings in actual application.

[0003] From the perspective of measurement efficiency and data integrity, the traditional single-point collection mode is limited by manual operation processes, requiring point-by-point deployment of measurement points, equipment setup, and reading recording. For the several-kilometer bridge deck range of long-span bridges, a single full-bridge measurement often takes several days, seriously slowing down the construction progress. At the same time, discrete point data can only cover limited measurement points, and cannot form a continuous bridge deck geometric shape record. When facing minor defects such as bridge deck local depression and edge protrusion, it is easy to miss the measurement due to sparse measurement points, making it difficult to fully reflect the bridge deck linear details and posing hidden dangers for subsequent construction quality assessment.

[0004] In terms of measurement accuracy and data collaboration, the traditional method is restricted by multiple factors: centering and leveling errors in manual operation processes, environmental disturbances such as wind and temperature changes on the construction site, and cumulative errors when splicing measurement data from different sections, which together cause large fluctuations in measurement result accuracy, making it difficult to meet the millimeter-level precision control requirements of ballastless track laying. More importantly, the traditional method lacks an efficient multi-source data fusion mechanism. The high-density point cloud collected by the three-dimensional laser scanner (only reflecting relative positions) and the absolute coordinates and elevation data obtained by the total station and electronic level are mutually disjointed, making it difficult to achieve collaborative correlation of geometric shape and accurate coordinates and to conduct comprehensive analysis of multi-dimensional linear parameters.

[0005] The limitations of traditional measurement methods are more pronounced in response to the unique requirements of ballastless track construction. Ballastless track involves multi-layered composite structures such as concrete bases and track slabs, demanding extremely high standards for the alignment of each structural layer and the uniformity of concrete thickness between layers. Traditional methods can only perform discrete point measurements on a single structural layer, failing to provide integrated analysis of multi-layered structures and making it difficult to accurately control the interlayer fit and thickness distribution characteristics. Furthermore, traditional measurements are mostly staged static inspections, unable to provide real-time feedback on alignment deviations during construction, and thus cannot provide dynamic data support for processes such as concrete pouring adjustments and track slab positioning corrections, failing to meet the real-time control requirements of high-precision ballastless track construction. Therefore, developing a bridge deck alignment measurement method that integrates the advantages of multi-source data, balances measurement efficiency and accuracy, and is adaptable to multi-layered structural analysis has become an urgent problem to be solved in the industry. Summary of the Invention

[0006] This invention aims to solve the problems of low efficiency, insufficient data density, limited accuracy, and lagging construction control in the existing measurement of bridge deck alignment of long-span bridges. It provides a rapid measurement and control method based on multi-source data fusion to achieve efficient acquisition, accurate analysis, and dynamic control of bridge deck alignment and related parameters.

[0007] To address the aforementioned deficiencies or improvement needs of existing technologies, as a first aspect of this invention, the present invention provides a method for rapid measurement of bridge deck alignment based on multi-source data fusion, comprising:

[0008] S1. Determine the measurement area, and calibrate the base station-type 3D laser scanner, total station, and electronic level based on the on-site control points;

[0009] S2. Obtain the relative coordinate point cloud data of the bridge deck structure using a 3D laser scanner, and simultaneously measure the absolute coordinates and elevation data using a total station and electronic level.

[0010] S3. Using the on-site control points as a reference, coordinate unification is carried out, multi-source data is integrated, and a three-dimensional model of the bridge deck structure in an absolute coordinate system is constructed.

[0011] S4. Based on the three-dimensional model of the bridge deck structure in the absolute coordinate system, parameters including the elevation, flatness, and overall linear curve of the bridge deck and concrete base are extracted by methods including point cloud slicing analysis, Gaussian filtering residual method, elevation difference calculation and curve fitting. The thickness and distribution characteristics of concrete between each structural layer are calculated by comparing the point clouds between layers. Then, deviation analysis is carried out on the extracted parameters in combination with the design standards to determine the difference between the current construction status and the design requirements.

[0012] S5. Based on the analysis results, output adjustment suggestions during the concrete pouring stage and positioning correction parameters during the track slab installation stage.

[0013] Further, the S1 field control point is CP III control network, the calibration includes three-dimensional laser scanner lens calibration, total station four-fold axis system error calibration, level The calibration includes three-dimensional laser scanner lens calibration, total station four-fold axis system error calibration, level

[0014] Further, the S3 coordinate unification process based on the field control point is:

[0015] The field CP III control network is set as the coordinate unification reference, and the coordinates of the field CP III control network in the absolute coordinate system are reference coordinates, denoted as , wherein is the absolute plane coordinate, is the absolute elevation, and the reference coordinate system is formed;

[0016] Suppose that any point in the bridge deck relative coordinate point cloud data collected by the base station type three-dimensional laser scanner is The coordinates only reflect the relative position relationship between points, without absolute coordinate reference;

[0017] Suppose that the absolute plane coordinates of the corresponding bridge deck key feature points measured by the total station are , and the absolute elevations of the corresponding points measured by the electronic level are , and the two together form the absolute coordinates of the feature points ;

[0018] The coordinate conversion relationship is established, and is taken as the reference, and the coordinate difference between and is calculated:

[0019] ,

[0020] ,

[0021] ,

[0022] The difference is taken as the conversion compensation, and substituted into all relative coordinate point cloud data to obtain the absolute coordinates of each point , wherein is the original relative coordinate;

[0023] After the coordinate conversion of all point cloud data is completed, the converted absolute coordinate point cloud data is compared with the absolute coordinate data directly measured by the total station and the electronic level. If the coordinate difference of any corresponding point is within the allowable error range, the coordinate unification is completed. If the error range is exceeded, the matching accuracy of the feature points is rechecked, and the above conversion steps are repeated until all data remains consistent under the same absolute coordinate system. ​

[0024] Further, the specific process of the S4 midpoint cloud slice is:

[0025] Let the point cloud set of the bridge deck structure three-dimensional model in the absolute coordinate system be , where represents the absolute plane horizontal coordinate, represents the absolute plane longitudinal coordinate, represents the absolute elevation, is the value range of the absolute coordinate parameter; a set of cross-section planes parallel to an axis is set along the bridge deck, and the plane equation is uniformly represented as , is a fixed coordinate axis, and axis or axis is taken; is the fixed coordinate value on the axis, ; the cross-section plane set is formed;

[0026] For each cross-section plane , the intersection of the cross-section plane and the point cloud set is calculated to obtain the point cloud subset in the plane: when or , ;

[0027] For all points in , the coordinate axis perpendicular to the fixed axis is sorted to obtain the ordered point cloud sequence , where when , or when , and or ;

[0028] The adjacent points and in are sequentially connected to form the bridge deck cross-section contour line in the cross-section plane , ; by comparing the coordinate parameter differences of , the geometric morphological change data of the bridge deck structure along the set axis direction are obtained.

[0029] Further, the specific method of the S4 elevation difference calculation is:

[0030] The ordered point cloud sequence obtained based on the point cloud slice analysis is , where is the fixed axis Vertical plane coordinates For the cutting plane on the fixed axis The coordinates on, This is the absolute elevation;

[0031] Based on the flatness detection units designed for the bridge deck, continuous point cloud segments are divided, and the point cloud within a certain detection segment is denoted as... , , To detect the number of point clouds within the segment;

[0032] Calculate detection segment mean elevation of all points within This average value is used as the "baseline elevation" for the test section;

[0033] For each point within the detection segment Calculate its elevation deviation from the baseline. Extract the maximum elevation deviation value within the detection section. ;

[0034] The maximum elevation deviation is calculated on a per-section basis. and the corresponding detection segment length The data is correlated to form a "maximum elevation deviation within the segment - detection length" data pair. By comparing with design standards, it is determined whether the flatness of the inspection section meets the standard, and the specific point with the largest deviation is located. .

[0035] Furthermore, the specific method for curve fitting in S4 is as follows:

[0036] An ordered point cloud sequence of the bridge deck along a set axis obtained from point cloud slices. , For axis mileage coordinates, Assuming absolute elevation, and based on the curvature change threshold of the designed alignment, the sequence is divided into several continuous smooth segments. The point cloud data of a certain smooth segment is denoted as... ;

[0037] In the smooth section Inside, take the first and last points. and Draw a straight line Calculate the distance to each of the remaining points within the segment. Vertical distance:

[0038] ,

[0039] Find The point corresponding to the maximum value ,by , , Draw a polyline for the vertex Calculate the distance from each point within this segment to The vertical distance, until all points All are less than the design tolerance.

[0040] By connecting the final broken lines of each smooth segment, a piecewise fitting curve that closely resembles the actual shape of the bridge deck is formed. The slope of each segment of the curve is then used to determine the curve's shape. Calculate the slope along the axis by using the ratio of the slope difference between adjacent segments to the mileage difference. The linear parameters are extracted by quantizing the curvature change.

[0041] Furthermore, the positioning correction parameters in S5 include the translation amount, rotation angle, and elevation adjustment value of the track plate.

[0042] As a second aspect of the present invention, the present invention provides a rapid measurement system for bridge deck alignment based on multi-source data fusion, comprising:

[0043] The measurement preparation and equipment calibration unit is used to determine the measurement area and calibrate the base station-type 3D laser scanner, total station and electronic level based on the field control points.

[0044] The multi-source data collaborative acquisition unit is used to acquire relative coordinate point cloud data of the bridge deck structure through a 3D laser scanner, and simultaneously use a total station and electronic level to measure absolute coordinate and elevation data.

[0045] The data fusion and modeling unit is used to unify coordinates based on on-site control points, fuse multi-source data, and construct a three-dimensional model of the bridge deck structure in an absolute coordinate system.

[0046] The parameter extraction and deviation analysis unit is used to extract parameters including the elevation, flatness, and overall linear curve of the bridge deck and concrete base based on the three-dimensional model of the bridge deck structure in the absolute coordinate system. It uses methods including point cloud slicing analysis, Gaussian filtering residual method, elevation difference calculation and curve fitting to extract parameters. It calculates the concrete thickness and distribution characteristics between each structural layer by comparing the point clouds between layers. Then, it performs deviation analysis on the extracted parameters in combination with the design standards to determine the difference between the current construction status and the design requirements.

[0047] The construction control and adjustment unit is used to output adjustment suggestions during the concrete pouring stage and positioning correction parameters during the track slab installation stage, based on the analysis results.

[0048] As a third aspect of the invention, the invention provides a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor of any step of the method for rapid measurement of bridge deck alignment based on multi-source data fusion.

[0049] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0050] 1. The bridge deck linear rapid measurement method based on multi-source data fusion of the present application, by taking the field CP III control network as the unified reference, special calibration is carried out on the base station type three-dimensional laser scanner, total station and electronic level, and synchronous multi-source data collaborative collection is carried out - the three-dimensional laser scanner obtains full-domain high-density point cloud data of the bridge deck, the total station measures the absolute plane coordinates, and the electronic level collects absolute elevation data, and ensures that the three types of data are time-synchronized. This technical feature effectively solves the problems of insufficient equipment precision and low data collection efficiency in traditional measurement, greatly shortens the time consumption of data collection of large-span bridge decks, and simultaneously compensates for the data density defects of single-point measurement through multi-device collaboration, providing full-domain, complete geometric and coordinate data support for subsequent analysis.

[0051] 2. The bridge deck linear rapid measurement method based on multi-source data fusion of the present application, by taking the CP III control network as the reference, the relative coordinate point cloud of the three-dimensional laser scanner is unified with the absolute coordinates and elevation data of the total station and electronic level by using the coordinate conversion algorithm, after denoising, filtering and point cloud simplification processing, the three-dimensional model of the bridge deck structure under the absolute coordinate system is constructed. This technical feature breaks through the limitation of poor multi-source data fusion in traditional measurement, eliminates the matching error between relative coordinates and absolute coordinates, so that the three-dimensional model can accurately present the actual geometric shape of the bridge deck and the concrete base. Compared with traditional discrete point modeling, the model resolution is significantly improved, providing a high-precision, full-dimensional spatial data basis for key parameter extraction and avoiding analysis deviation caused by data splicing error.

[0052] 3. The bridge deck linear rapid measurement method based on multi-source data fusion of the present application, by relying on the three-dimensional model under the absolute coordinate system, using methods such as point cloud slice analysis, elevation difference calculation and curve fitting, the elevation, flatness, overall linear curve and other parameters of the bridge deck and the concrete base are extracted, the thickness and distribution characteristics of the concrete of each structure layer of the ballastless track are obtained by comparing the point clouds between layers, and deviation analysis is carried out in combination with the design standard. This technical feature solves the problem of single-dimensional parameter analysis and construction control lag in traditional measurement, realizes collaborative analysis of multi-dimensional parameters, can accurately locate construction problems such as flatness overage and interlayer thickness anomaly, provides real-time data basis for concrete pouring adjustment and track slab positioning correction, and meets the dynamic control requirements of high-precision construction such as ballastless track. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 The flowchart of the bridge deck linear rapid measurement method based on multi-source data fusion of the present application;

[0054] Figure 2An overall schematic diagram of the ballastless track according to the embodiment of the present application;

[0055] Figure 3 A layered schematic diagram of the ballastless track according to the embodiment of the present application;

[0056] Figure 4 A system unit diagram according to the embodiment of the present application. DETAILED DESCRIPTION

[0057] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0058] Embodiment 1

[0059] Please refer to Figure 1 The embodiment 1 provides a bridge deck linear rapid measurement method based on multi-source data fusion, comprising:

[0060] S1. Determine the measurement area, and calibrate the base station type three-dimensional laser scanner, total station and electronic level with the on-site control point as the reference;

[0061] S2. Obtain the relative coordinate point cloud data of the bridge deck structure by the three-dimensional laser scanner, and simultaneously measure the absolute coordinates and elevation data by the total station and electronic level;

[0062] S3. Perform coordinate unification with the on-site control point as the reference, fuse the multi-source data, and construct the three-dimensional model of the bridge deck structure under the absolute coordinate system;

[0063] S4. Based on the three-dimensional model of the bridge deck structure under the absolute coordinate system, extract the parameters including the elevation, flatness, and overall linear curve of the bridge deck and concrete base by methods including point cloud slice analysis, Gaussian filter residual method, elevation difference calculation, and curve fitting, calculate the concrete thickness and distribution characteristics between the structure layers through the interlayer point cloud comparison, and then combine the design standard to carry out deviation analysis on the extracted parameters to judge the difference between the current construction state and the design requirement;

[0064] S5. According to the analysis result, output adjustment suggestions in the concrete pouring stage, and output positioning correction parameters in the track slab installation stage.

[0065] The embodiment 1 further expands the above steps; Figure 2 And Figure 3From bottom to top, they are reinforced concrete base, geotextile, self-compacting concrete layer and track slab. The reinforced concrete base is the foundation bearing layer of the whole structure, the geotextile plays a role of isolation and protection, the self-compacting concrete layer realizes the close combination of the track slab and the base, and the track slab is the key component directly bearing the track.

[0066] The three-dimensional model constructed by multi-source data fusion in this embodiment 1 can accurately extract the geometric parameters of each layer structure. For example, the thickness and distribution characteristics of the self-compacting concrete layer are calculated by comparing the point clouds between layers, the deviation is analyzed in combination with the design standard, and then the pouring adjustment of the self-compacting concrete is guided in the concrete pouring stage, the positioning correction parameters are output in the track slab installation stage, the linear matching and construction precision of each layer structure are ensured, and finally the overall construction quality of the ballastless track is guaranteed.

[0067] (1) Measurement preparation and equipment calibration

[0068] In the construction of long-span bridge deck and ballastless track, the bridge deck linear measurement needs to solve the problems of insufficient data density and fragmented multi-source data in traditional methods, and needs to build a unified and accurate implementation framework from the basic link. The measurement area covers the full width of the bridge deck and the construction range of each structure layer of the ballastless track, and key control nodes such as the beam end connection and track slab installation positioning points are marked to avoid missing measurement.

[0069] The CPⅢ control network already laid on site is used as a unified reference, and its plane coordinate and elevation data match the bridge construction design coordinate system, providing a consistent reference for subsequent data integration and eliminating data splicing errors caused by inconsistent traditional measurement references.

[0070] The measurement equipment is calibrated: the lens calibration of the base station type three-dimensional laser scanner is completed with a special calibration board to correct the imaging distortion; the shaft error correction of the total station is carried out to adjust the perpendicularity of the collimation axis, horizontal axis and vertical axis to ensure the plane coordinate measurement accuracy; the electronic level is tested and calibrated by the round trip measurement method to eliminate the system error of the height measurement, so that the accuracy of the three-dimensional laser scanner, total station and electronic level meets the millimeter-level control requirements of the ballastless track laying, laying a foundation for the subsequent synchronous acquisition of bridge deck relative coordinate point cloud, absolute coordinate and elevation data, and realizing efficient fusion of multi-source data.

[0071] (2) Multi-source data collaborative acquisition

[0072] ​After the completion of equipment calibration, the data acquisition link is entered immediately. A base station type three-dimensional laser scanner is used to cover the bridge concrete base, bridge deck pavement layer and track construction related structure with a set scanning path to carry out global three-dimensional scanning operation, to ensure that the scanning range covers the core construction area completely, and the point cloud data density obtained is not less than 50 points / m2. The high-density point cloud completely records the relative geometric shape of each structure surface, including concave, convex and other subtle features, to provide data support for subsequent accurate restoration of the spatial form of the bridge deck and concrete base.

[0073] Synchronously with the three-dimensional scanning, the total station and electronic level start collaborative measurement: the total station takes the CP III control network as a reference to measure each point of the key feature points in the network, such as the control points, the bridge deck beam end joint, the preset installation point of the track slab, and the bridge deck node corresponding to the support, to accurately collect the absolute plane coordinates of each point; the electronic level also takes the CP III control network as a reference to measure the elevation measurement points in the network and on the bridge deck at certain intervals to obtain the absolute elevation data of each point, forming a matching data group of absolute coordinates and elevation.

[0074] During the acquisition process, through a unified time synchronization device, the three-dimensional laser scanner, total station and electronic level complete data acquisition in the corresponding area within the same time period, avoiding differences in measurement environment caused by different starting times of equipment, and minimizing the interference of environmental factors such as temperature and humidity fluctuations, instantaneous wind changes and other factors on the measurement results of different equipment, to ensure the consistency of the three types of data in spatial position and time dimension, and to lay an accurate foundation for the subsequent coordinate unification and efficient fusion of multi-source data.

[0075] (3) Data fusion and modeling

[0076] After the completion of multi-source data acquisition, the data processing and modeling link is entered. The on-site CP III control network is taken as the coordinate unification reference, and the coordinates of the control network in the absolute coordinate system constitute the reference coordinate system as the reference standard for data fusion.

[0077] For the relative coordinate point cloud data collected by the three-dimensional laser scanner, the corresponding bridge deck key feature points measured by the total station and electronic level are selected, the relative coordinates of the feature points obtained by the scanner are matched with the absolute plane coordinates of the point measured by the total station and the absolute elevation measured by the electronic level, and the plane and elevation differences between the two groups of coordinates are calculated, which are used as the conversion compensation. The compensation is substituted into all point cloud relative coordinate data to complete the conversion of each point from relative coordinates to absolute coordinates, so that the point cloud data originally reflecting only the relative position is included in the absolute coordinate system.

[0078] In a preferred embodiment, the specific process of coordinate unification based on the on-site control points is as follows:

[0079] Set the field CIII control network as the coordinate unified reference, its coordinate in the absolute coordinate system is the reference coordinate, denoted as , wherein, is the absolute plane coordinate, is the absolute elevation, which constitutes the reference coordinate system;

[0080] Set any point in the bridge deck relative coordinate point cloud data collected by the base station type three-dimensional laser scanner as , which only reflects the relative position relationship between points and has no absolute coordinate reference;

[0081] Set the absolute plane coordinates of the corresponding bridge deck key feature points measured by the total station as , and the absolute elevation of the corresponding points measured by the electronic level as , which together constitute the absolute coordinate of the feature point;

[0082] Establish a coordinate conversion relationship, taking as the reference, and calculate the coordinate difference between and :

[0083] ,

[0084] ,

[0085] ,

[0086] Substitute the difference value as the conversion compensation into all relative coordinate point cloud data to obtain the absolute coordinates of each point , wherein is the original relative coordinate;

[0087] After conversion, compare the converted point cloud absolute coordinate data with the absolute coordinate data directly measured by the total station and electronic level. If the coordinate difference of all corresponding points is within the allowable error range, the coordinate unification and spatial matching of multi-source data are completed. If there are points exceeding the error range, recheck the accuracy of feature point matching, repeat the coordinate conversion steps until all data are consistent under the same absolute coordinate system.

[0088] Subsequently, process the fused multi-source data: remove abnormal points generated by environmental interference and equipment jitter through denoising algorithm, smooth data fluctuations using filtering technology, and then retain key geometric information and remove redundant data through point cloud simplification. Based on the processed effective data, construct a three-dimensional reverse model of the concrete base and bridge deck structure under the absolute coordinate system, which completely presents the actual geometric shape of the bridge deck and each structural layer, and provides intuitive and accurate model support for subsequent linear parameter extraction.​

[0089] (4) Parameter extraction and deviation analysis

[0090] After completing the construction of the three-dimensional model of the bridge deck structure in the absolute coordinate system, the parameter extraction and deviation analysis link is entered, which provides a basis for construction quality control through multi-dimensional data analysis. This link relies on the model to carry out point cloud slicing analysis, elevation difference calculation, and curve fitting, and simultaneously analyzes the interlayer characteristics of the multi-layer structure of the ballastless track, achieving comprehensive quantification of the bridge deck alignment and providing accurate guidance for construction adjustment.

[0091] In the point cloud slicing analysis, based on the model point cloud set, a set of slicing planes parallel to a certain axis is set along the bridge deck, and each plane corresponds to a specific coordinate value of the fixed coordinate axis. The intersection of the plane and the point cloud is extracted to form a point cloud subset, which is sorted according to the coordinates perpendicular to the fixed axis to obtain an ordered sequence, and the adjacent points are connected to form a cross-sectional contour line. By comparing the parameter differences of each contour line, the geometric shape changes of the bridge deck along the set axis are clearly presented, providing basic data for subsequent segmented analysis.

[0092] In a preferred embodiment, the specific process of point cloud slicing is as follows:

[0093] Let the point cloud set of the three-dimensional model of the bridge deck structure in the absolute coordinate system be , where represents the absolute plane horizontal coordinate, represents the absolute plane longitudinal coordinate, represents the absolute elevation, is the value range of the absolute coordinate parameter; a set of slicing planes parallel to a certain axis is set along the bridge deck, and the plane equation is uniformly represented as , is the fixed coordinate axis, taking axis or axis; is the fixed coordinate value on this axis, ; form a set of slicing planes ;

[0094] For each slicing plane , calculate the intersection of its point cloud set to obtain the point cloud subset in this plane: when , or ;

[0095] Sort all points in according to the coordinate axis perpendicular to the fixed axis to obtain the ordered point cloud sequence , where when , or ​Time, , and satisfy or ;

[0096] sequentially connecting adjacent points and forming a bridge deck cross-sectional profile line in the cross-sectional plane , , ; by comparing the coordinate parameter differences, the geometric morphological change data of the bridge deck structure along the set axis direction are obtained.

[0097] The elevation difference calculation is based on the ordered point cloud sequence obtained by slicing, and the point cloud segments are divided according to the design flatness detection unit. The elevation mean value in the segment is taken as the reference elevation line, the deviation of each point from the reference line is calculated, and the maximum deviation value is extracted. Combined with the detection segment length, a data pair is formed. This process converts the bridge deck flatness from an abstract form to a quantitative index, which directly serves the judgment of whether the flatness meets the standard.

[0098] In a preferred embodiment, the specific method of elevation difference calculation is:

[0099] Based on the ordered point cloud sequence obtained by point cloud slicing analysis , , wherein is the planar coordinate perpendicular to the fixed axis , is the coordinate value of the cross-sectional plane on the fixed axis , and is the absolute elevation; According to the flatness detection unit of the bridge deck design, the continuous point cloud segments are divided, and the point cloud in a certain detection segment is recorded as

[0100] , , , and is the number of point clouds in the detection segment;

[0101] The elevation mean value of all points in the detection segment is calculated , and the mean value is taken as the "reference elevation line" of the detection segment;

[0102] For each point in the detection segment, the elevation deviation of the point from the reference elevation line is calculated, and the maximum elevation deviation value in the detection segment is extracted ;

[0103] Taking the detection segment as the unit, the maximum elevation deviation is associated with the corresponding detection segment length to form a "maximum elevation deviation in the segment-detection length" data pair​ By comparing with design standards, it is determined whether the flatness of the inspection section meets the standard, and the specific point with the largest deviation is located. .

[0104] In the curve fitting stage, the ordered point cloud along the axial direction is divided into smooth segments according to the design curvature change threshold. Within each smooth segment, the distances from the remaining points to the straight line are calculated by drawing a straight line from the first and last points. The point with the largest distance is then combined with the first and last points to form a broken line. This calculation is repeated until the distances of all points are less than the design allowable deviation. The broken lines of each segment are then connected to form a piecewise fitting curve that closely matches the actual situation. The slope is calculated using the curve slope, and the curvature is quantified by the ratio of the slope difference between adjacent segments to the mileage difference. This allows for the precise extraction of core parameters such as the elevation of the bridge deck and concrete base, and the overall linear curve.

[0105] In a preferred embodiment, the specific method for curve fitting is as follows:

[0106] An ordered point cloud sequence of the bridge deck along a defined axis, obtained from point cloud slices. , For axis mileage coordinates, Assuming absolute elevation, and based on the curvature change threshold of the designed alignment, the sequence is divided into several continuous smooth segments. The point cloud data of a certain smooth segment is denoted as... ;

[0107] In the smooth section Inside, take the first and last points. and Draw a straight line Calculate the distance from each of the remaining points within the segment to... Vertical distance:

[0108] ,

[0109] Find The point corresponding to the maximum value ,by , , Draw a polyline for the vertex Calculate the distance from each point within this segment to The vertical distance, until all points All are less than the design tolerance.

[0110] By connecting the final broken lines of each smooth segment, a piecewise fitting curve that closely resembles the actual shape of the bridge deck is formed. The slope of each segment of the curve is then used to determine the curve's shape. Calculate the slope along the axis by using the ratio of the slope difference between adjacent segments to the mileage difference. The linear parameters are extracted by quantizing the curvature change.

[0111] For the multi-layer structure of the ballastless track, the concrete thickness and distribution characteristics between layers such as the base and the track slab are calculated by comparing the point cloud data of each structural layer, and the construction quality between layers is mastered. Finally, all the extracted parameters are compared with the design standards to carry out deviation analysis and clarify the differences between the current construction and the design requirements, providing data support for subsequent process adjustment and ensuring that the construction meets the precision standards.

[0112] (5) Construction control and adjustment

[0113] After completing the bridge line parameter extraction and deviation analysis, combined with the accurate data obtained by the early multi-source data fusion, the technical scheme is output for the two construction stages of concrete pouring and track slab installation, realizing the direct guidance of measurement data to construction.

[0114] In the concrete pouring stage, the bridge surface flatness deviation (the maximum elevation deviation of each detection section and the corresponding position), the linear curve deviation (the difference between the longitudinal slope, the transverse curvature and the design value), and the concrete thickness distribution characteristics (local thickness deficiency, uneven area coordinates) between layers are obtained by point cloud slicing, elevation difference calculation and interlayer comparison. Lock the weak areas of pouring. For the flatness overrunning section, combined with the elevation deviation distribution gradient, determine the specific range and boundary coordinates of the pouring and pouring; for the abnormal area of interlayer thickness, refer to the design thickness standard, calculate the adjustment value of the concrete pouring amount at the corresponding position. According to this, generate pouring adjustment suggestions, clarify the pouring amount distribution, pouring sequence, and key areas and time of vibration, guide the site construction, and reduce the subsequent linear deviation.

[0115] Before the track slab installation, integrate the concrete structure layer thickness distribution data (the thickness of each layer changes along the bridge mileage) and the bridge surface overall linear deviation parameters (the spatial distribution of longitudinal slope, transverse curvature and elevation deviation) obtained in the early stage, and establish a matching model of the design position of the track slab and the actual form of the bridge surface through the adaptive algorithm. For the bridge elevation deviation, combined with the design elevation of the track slab, calculate the millimeter-level elevation adjustment value of each track slab; according to the bridge surface plane linear deviation and the anchoring requirements of the track slab, determine the horizontal X-axis and Y-axis translation amount; combined with the curvature change of the curved section bridge surface and the track slab joint standard, calculate the rotation angle around the vertical axis, form the positioning correction parameter group containing the translation amount (X direction, Y direction), rotation angle and elevation adjustment value. The parameters are all corresponding to the track slab number and installation mileage coordinates. Output the parameters to the intelligent installation equipment of the track slab through the data interface, and the equipment automatically adjusts the installation posture to realize high-precision positioning of the track slab and ensure the quality of the ballastless track laying.

[0116] Example 2

[0117] Please refer to Figure 4 The embodiment 2 provides a bridge surface linear rapid measurement system based on multi-source data fusion, which comprises:

[0118] A measurement preparation and device calibration unit is configured to determine a measurement area, calibrate a base station type three-dimensional laser scanner, a total station and an electronic level based on a field control point;

[0119] A multi-source data collaborative acquisition unit is configured to acquire relative coordinate point cloud data of a bridge deck structure by using a three-dimensional laser scanner, and synchronously measure absolute coordinates and elevation data by using a total station and an electronic level;

[0120] A data fusion and modeling unit is configured to unify coordinates based on a field control point, fuse multi-source data and construct a three-dimensional model of a bridge deck structure under an absolute coordinate system;

[0121] A parameter extraction and deviation analysis unit is configured to extract parameters including elevations of a bridge deck and a concrete base, flatness, overall linear curves and the like based on a three-dimensional model of a bridge deck structure under an absolute coordinate system by using methods including point cloud slice analysis, Gaussian filter residual error method, elevation difference calculation and curve fitting, calculate the thickness and distribution characteristics of concrete between structure layers by comparing point clouds between layers, and perform deviation analysis on the extracted parameters in combination with design standards to determine the difference between a current construction state and design requirements;

[0122] A construction control and adjustment unit is configured to output adjustment suggestions during a concrete pouring stage and output positioning correction parameters during a track slab installation stage based on analysis results.

[0123] Embodiment 3

[0124] The embodiment 3 further provides a computer readable storage medium, and the computer readable storage medium stores a computer program. The computer program is executed by a processor to implement any step of the bridge deck linear rapid measurement based on multi-source data fusion.

[0125] The computer readable storage medium can include a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk and the like various storage program codes.

[0126] The computer readable storage medium provided in the present application is introduced in the above method embodiments, and the present application will not be repeated here.

[0127] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A rapid measurement method for bridge deck alignment based on multi-source data fusion, characterized in that, include: S1. Determine the measurement area, and calibrate the base station-type 3D laser scanner, total station, and electronic level based on the on-site control points; S2. High-density point cloud data of the entire bridge deck was acquired using a 3D laser scanner, absolute plane coordinates were measured using a total station, and absolute elevation data was collected using an electronic level, ensuring that the three types of data were synchronized in time. A coordinate transformation algorithm was then used to unify the relative coordinate point cloud data from the 3D laser scanner with the absolute coordinates and elevation data from the total station and electronic level, thus constructing a 3D model of the bridge deck structure in an absolute coordinate system. This process eliminated the matching error between relative and absolute coordinates, enabling the 3D model to accurately represent the actual geometry of the bridge deck and concrete base. Compared with traditional discrete point modeling, this avoids analytical biases caused by data splicing errors. S3. Using the on-site control points as a reference, coordinate unification is carried out, multi-source data is integrated, and a three-dimensional model of the bridge deck structure in an absolute coordinate system is constructed. S4. Based on the three-dimensional model of the bridge deck structure in the absolute coordinate system, parameters including the elevation, flatness, and overall linear curve of the bridge deck and concrete base are extracted by methods including point cloud slicing analysis, Gaussian filtering residual method, elevation difference calculation and curve fitting. The thickness and distribution characteristics of concrete between each structural layer are calculated by comparing the point clouds between layers. Then, deviation analysis is carried out on the extracted parameters in combination with the design standards to determine the difference between the current construction status and the design requirements. S5. Based on the analysis results, output adjustment suggestions during the concrete pouring stage and positioning correction parameters during the track slab installation stage; The process of calculating the concrete thickness and distribution characteristics between structural layers by comparing point clouds between layers is for multi-layer structures of ballastless track. It is to grasp the construction quality between layers and finally compare all extracted parameters with design standards to carry out deviation analysis and clarify the differences between the current construction and design requirements. The specific process of S5 is as follows: During the concrete pouring stage, based on the bridge deck smoothness deviation, linear curve deviation, and concrete thickness distribution characteristics between structural layers obtained through point cloud slicing, elevation difference calculation, and inter-layer comparison, weak pouring areas are identified. For road sections with excessive smoothness, the specific range and boundary coordinates of supplementary pouring and reduced pouring are determined by combining the elevation deviation distribution gradient. For areas with abnormal inter-layer thickness, the adjustment value of concrete pouring volume at the corresponding location is calculated with reference to the design thickness standard. Based on this, pouring adjustment suggestions are generated, clarifying the pouring volume distribution, pouring sequence, key areas for vibration, and duration for each area. Before installing the track slabs, the previously obtained data on the thickness distribution of the concrete structure layers and the overall alignment deviation parameters of the bridge deck are integrated. A matching model between the design position of the track slabs and the actual shape of the bridge deck is established through an adaptation algorithm. For the elevation deviation of the bridge deck, the millimeter-level elevation adjustment value of each track slab is calculated in combination with the design elevation of the track slabs. Based on the horizontal alignment deviation of the bridge deck and the anchorage requirements of the track slabs, the translation amounts in the horizontal X and Y axes are determined. Combining the curvature changes of the curved bridge deck and the standard of the track slab splicing joints, the rotation angle around the vertical axis is calculated, forming a positioning correction parameter set containing the X-axis translation amount, Y-axis translation amount, rotation angle, and elevation adjustment value. All parameters correspond to the track slab number and installation mileage coordinates. Among them, the thickness distribution data of the concrete structure layers is the variation law of the thickness of each layer along the bridge deck mileage; the overall alignment deviation parameters of the bridge deck are the spatial distribution of longitudinal slope, transverse curvature and elevation deviation.

2. The method for rapid measurement of bridge deck alignment based on multi-source data fusion according to claim 1, characterized in that, The field control points in S1 are the CPⅢ control network. The calibration includes 3D laser scanner lens calibration, total station quadruple axis error checking, and leveling instrument calibration. Including angle calibration, crosshair calibration, and circular bubble level calibration.

3. The method for rapid measurement of bridge deck alignment based on multi-source data fusion according to claim 1, characterized in that, The specific process of coordinate unification based on field control points in S3 is as follows: The field CPⅢ control network is set as the unified coordinate reference, and its coordinates in the absolute coordinate system are the reference coordinates, denoted as . ,in, For absolute planar coordinates, The absolute elevation forms the reference coordinate system; Let any point in the relative coordinate point cloud data of the bridge deck acquired by the base station-type 3D laser scanner be... This coordinate system only reflects the relative positional relationship between points and has no absolute coordinate reference. Assume the total station measurement and The corresponding absolute planar coordinates of the key feature points on the bridge deck are The absolute elevation of the corresponding point measured by the electronic level is The two together constitute the absolute coordinates of the feature point. ; Establish coordinate transformation relationships, in order to Based on the benchmark, through calculation and Coordinate difference between: ， ， ， Using this difference as a transformation compensation value, we substitute it into all relative coordinate point cloud data to obtain the absolute coordinates of each point. ,in The original relative coordinates are used. After completing the coordinate transformation of all point cloud data, the transformed absolute coordinate point cloud data is compared with the absolute coordinate data directly measured by the total station and electronic level. If the coordinate difference of any corresponding point is within the allowable error range, the coordinate unification is completed. If it exceeds the error range, the accuracy of feature point matching is rechecked, and the above transformation steps are repeated until all data are consistent under the same absolute coordinate system.

4. The method for rapid measurement of bridge deck alignment based on multi-source data fusion according to claim 1, characterized in that, The specific process of point cloud slicing in S4 is as follows: Let the point cloud set of the 3D model of the bridge deck structure in the absolute coordinate system be... ,in Represents the absolute plane x-coordinate, Represents the absolute plane ordinate, Represents absolute elevation. The range of values ​​for the absolute coordinate parameters; a set of cutting planes parallel to a certain axis are defined along the bridge deck, and the plane equations are uniformly expressed as... , To fix the coordinate axes, take shaft or axis; These are fixed coordinate values ​​on this axis. Forming a group of cutting planes ; For each cutting plane Calculate its relationship with the point cloud set The intersection of these points yields a subset of the point cloud within the plane: hour, or hour, ; right All the points and fixed shafts Sorting along the vertical coordinate axes yields an ordered point cloud sequence. ,in, hour, ,or hour, And satisfy or ; Connect in sequence Middle adjacent points and Forming a cutting plane Bridge deck cross-sectional profile , By comparison By analyzing the differences in coordinate parameters, data on the geometric shape changes of the bridge deck structure along a set axis direction can be obtained.

5. The method for rapid measurement of bridge deck alignment based on multi-source data fusion according to claim 4, characterized in that, The specific method for calculating the elevation difference in S4 is as follows: Ordered point cloud sequence obtained from point cloud slice analysis ,in, hour, ,or hour, And satisfy or ; Based on the flatness detection units designed for the bridge deck, continuous point cloud segments are divided, and the point cloud within a certain detection segment is denoted as... , To detect the number of point clouds within a segment, where, hour, ,or hour, ; Calculate detection segment mean elevation of all points within This average value is used as the "baseline elevation" for the detection section; For each point within the detection segment Calculate its elevation deviation from the baseline. Extract the maximum elevation deviation value within the detection section. ; The maximum elevation deviation is calculated on a per-section basis. and the corresponding detection segment length The data is correlated to form a "maximum elevation deviation within the segment - detection length" data pair. By comparing with design standards, it is determined whether the flatness of the inspection section meets the standard, and the specific point with the largest deviation is located. .

6. The method for rapid measurement of bridge deck alignment based on multi-source data fusion according to claim 4, characterized in that, The specific method for curve fitting in S4 is as follows: An ordered point cloud sequence of the bridge deck along a set axis obtained from point cloud slices. , For axis mileage coordinates, Assuming absolute elevation, and based on the curvature change threshold of the designed alignment, the sequence is divided into several continuous smooth segments. The point cloud data of a certain smooth segment is denoted as... ; In the smooth section Inside, take the first and last points. and Draw a straight line Calculate the distance to each of the remaining points within the segment. Vertical distance: ， Find The point corresponding to the maximum value ,by , , Draw a polyline for the vertex Calculate again the distance from each point within the segment to... The vertical distance, until all points All are less than the design tolerance. By connecting the final broken lines of each smooth segment, a piecewise fitting curve that closely resembles the actual shape of the bridge deck is formed. The slope of each segment of the curve is then used to determine the curve's shape. Calculate the slope along the axis by using the ratio of the slope difference between adjacent segments to the mileage difference. The linear parameters are extracted by quantizing the curvature change.

7. A rapid measurement system for bridge deck alignment based on multi-source data fusion, characterized in that, include: The measurement preparation and equipment calibration unit is used to determine the measurement area and calibrate the base station-type 3D laser scanner, total station and electronic level based on the field control points. The multi-source data collaborative acquisition unit is used to acquire high-density point cloud data of the entire bridge deck through a 3D laser scanner, measure absolute plane coordinates with a total station, and acquire absolute elevation data with an electronic level, ensuring that the three types of data are synchronized in time. A coordinate transformation algorithm is used to unify the relative coordinate point cloud data of the 3D laser scanner with the absolute coordinates and elevation data of the total station and electronic level, and construct a 3D model of the bridge deck structure in an absolute coordinate system. This process eliminates the matching error between relative and absolute coordinates, enabling the 3D model to accurately represent the actual geometry of the bridge deck and concrete base. Compared with traditional discrete point modeling, it avoids analysis deviations caused by data splicing errors. The data fusion and modeling unit is used to unify coordinates based on on-site control points, fuse multi-source data, and construct a three-dimensional model of the bridge deck structure in an absolute coordinate system. The parameter extraction and deviation analysis unit is used to extract parameters including the elevation, flatness, and overall linear curve of the bridge deck and concrete base based on the three-dimensional model of the bridge deck structure in the absolute coordinate system. It uses methods including point cloud slicing analysis, Gaussian filtering residual method, elevation difference calculation and curve fitting to extract parameters. It calculates the concrete thickness and distribution characteristics between each structural layer by comparing the point clouds between layers. Then, it performs deviation analysis on the extracted parameters in combination with the design standards to determine the difference between the current construction status and the design requirements. The construction control and adjustment unit is used to output adjustment suggestions during the concrete pouring stage and positioning correction parameters during the track slab installation stage, based on the analysis results. Among them, the process of calculating the concrete thickness and distribution characteristics between structural layers by comparing the point clouds between layers is for multi-layer structures of ballastless track. This is to grasp the construction quality between layers and finally compare all extracted parameters with the design standards to carry out deviation analysis and clarify the differences between the current construction and design requirements. The construction control and adjustment unit is specifically used for: During the concrete pouring stage, based on the bridge deck smoothness deviation, linear curve deviation, and concrete thickness distribution characteristics between structural layers obtained through point cloud slicing, elevation difference calculation, and inter-layer comparison, weak pouring areas are identified. For road sections with excessive smoothness, the specific range and boundary coordinates of supplementary pouring and reduced pouring are determined by combining the elevation deviation distribution gradient. For areas with abnormal inter-layer thickness, the adjustment value of concrete pouring volume at the corresponding location is calculated with reference to the design thickness standard. Based on this, pouring adjustment suggestions are generated, clarifying the pouring volume distribution, pouring sequence, key areas for vibration, and duration for each area. Before installing the track slabs, the previously obtained data on the thickness distribution of the concrete structure layers and the overall alignment deviation parameters of the bridge deck are integrated. A matching model between the design position of the track slabs and the actual shape of the bridge deck is established through an adaptation algorithm. For the elevation deviation of the bridge deck, the millimeter-level elevation adjustment value of each track slab is calculated in combination with the design elevation of the track slabs. Based on the horizontal alignment deviation of the bridge deck and the anchorage requirements of the track slabs, the translation amounts in the horizontal X and Y axes are determined. Combining the curvature changes of the curved bridge deck and the standard of the track slab splicing joints, the rotation angle around the vertical axis is calculated, forming a positioning correction parameter set containing the X-axis translation amount, Y-axis translation amount, rotation angle, and elevation adjustment value. All parameters correspond to the track slab number and installation mileage coordinates. Among them, the thickness distribution data of the concrete structure layers is the variation law of the thickness of each layer along the bridge deck mileage; the overall alignment deviation parameters of the bridge deck are the spatial distribution of longitudinal slope, transverse curvature and elevation deviation.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is executed by a processor according to any one of claims 1-6, a method for rapid measurement of bridge deck alignment based on multi-source data fusion.

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