CN-122015818-A - Method for detecting eccentricity of railway line bridge by air-rail cooperation

CN122015818ACN 122015818 ACN122015818 ACN 122015818ACN-122015818-A

Abstract

The invention discloses an eccentric detection method of a railway line bridge with air-rail cooperation, which comprises the steps of S1, establishing a line control network consisting of a plane control network and a height control network, S2, measuring the relative position of a rail and an on-line structure at the cross section of a bridge, S3, measuring the relative position of a beam edge and the on-line structure at the cross section of the bridge, and S4, carrying out space-time synchronization and fusion on data obtained in the S2 and the S3 to obtain a line bridge eccentric measurement result. The method has the advantages of high detection efficiency, accurate detection, high safety and low labor cost.

Inventors

Fan Tanqi
ZHAO QIAN
AN RAN
ZHANG YU
NIU YONGXIAO
LIN YONGWEI
QIN SHOUPENG
OuYang Quanhuan
HUANG WEILI
ZHENG HEMIN
TAN ZHAO
DENG JIWEI
QI CHUNYU
WANG RAN
SHI DEBIN
CUI BIN

Assignees

中国铁路设计集团有限公司

Dates

Publication Date: 20260512
Application Date: 20251225

Claims (10)

1. The method for detecting the eccentricity of the railway line bridge by the cooperation of the empty rail and the rail is characterized by comprising the following steps of: S1, establishing a line control network consisting of a plane control network and a height control network; s2, measuring geometric parameters of a track by taking the line control network as a reference, combining calibration values of an inertial navigation center and a laser radar center, calculating track line data of the laser radar center in different sampling time sequences, carrying out mobile three-dimensional scanning on an on-line structure of a railway bridge, fusing the obtained laser scanning data and the track line data into a three-dimensional point cloud of the on-line structure of the railway bridge, converting a track center coordinate into a track mileage, selecting a position of a bridge cross section, extracting the cross section of the position from the three-dimensional point cloud data, and measuring the relative position of a beam edge at the cross section and the on-line structure; s3, designing an unmanned aerial vehicle route according to the geometric parameters of the track obtained in the S2, collecting route line data of unmanned aerial vehicle flight and laser data on two sides of a bridge by taking the route control network as a control reference, unifying a mileage system of unmanned aerial vehicle measurement data, extracting a cross section of three-dimensional point cloud on the outer side of the bridge according to the method of the S2, and measuring the relative position of a beam edge and an on-line structure at the cross section; and S4, carrying out data fusion on the measurement results of the S2 and the S3 to obtain a line bridge eccentricity measurement result.
2. The method for detecting eccentricity of a railway line bridge according to claim 1, wherein the laser scanning data in S2 includes a distance measurement value synchronized with time And scanning angle [ ] ) Global coordinates of each point in the three-dimensional point cloud Calculated by Euler transformation: ; Wherein, the For rotation of the matrix, the Euler angles in the trajectory are used (Yaw), (Pitching), (Roll) pressing The sequential construction is as follows: ; Is a translation vector ; For the point coordinates of the laser scanner on the track inspection instrument in the local coordinate system, the distance measurement value is used for measuring the distance And scan angle And (3) calculating: ; Wherein, the Is a horizontal angle; is a vertical angle.
3. The method for detecting the eccentricity of a railway line bridge according to claim 1, wherein the geometric parameters of the track in S2 include a dimensional parameter of the track, a geometric parameter of the shape, and a three-dimensional coordinate of a center line of the track , , ) The method for converting the track center coordinates into track mileage comprises the following steps: s231, orbital line fitting, comprising: (1) Straight line segment fitting, setting a straight line equation as The solution of the least squares method is shown as follows: , ; (2) Fitting a circular curve, namely setting the center of the circular curve as the center of the circle Radius of The sum of squares of the residuals is minimized as shown in the following equation: ; (3) Moderating curve fitting, namely adopting a cubic parabola model, Is a radius of a circular curve, To mitigate the total length of the curve, then: ; s232, a linear reference system is established, and the interconversion of the track center coordinates and the track mileage is realized through the forward calculation and the backward calculation of the mileage point coordinates, and the specific steps are as follows: 1) Converting mileage into coordinates: for straight line segments, the conversion formula is: , ; Wherein the method comprises the steps of The coordinates are the starting point coordinates of the straight line segment; is azimuth; Is mileage; for a circular curve segment, the conversion formula is: , ; Wherein the method comprises the steps of R is the radius of the circular curve section; the starting mileage of the circular curve segment; Is the initial tangential angle; For the mild curve segment, the conversion formula is: , ; Wherein the method comprises the steps of L is an integral variable, which represents a variable in the process of calculating the length of the curve; To mitigate the starting mileage of the curve segment; 2) Converting the coordinates into mileage, wherein the mileage is calculated iteratively by the following formula: , , Wherein the method comprises the steps of Is a positive calculation formula, and is characterized by that, Is a derivative thereof; ≥0。
4. The method for detecting eccentricity of a railway line bridge according to claim 1, wherein the method for extracting a cross section from three-dimensional point cloud data in S2 comprises: S241, calculating the position of the cross section of the bridge: according to the fitting result of the design file or the track center line, calculating Three-dimensional coordinates of the center of the track on the cross section at mileage Azimuth angle of tangent line And gradient of ; S242, constructing a bridge cross section equation: the bridge cross section is perpendicular to the track center line, and the plane equation is expressed as: , Wherein, the , , , ; S243, point cloud extraction: extracting point cloud data in the bridge cross section range from the three-dimensional point cloud by using the equation in S242 to form a bridge cross section point set : , Wherein, the The point is the ith point in the point set of the bridge cross section, and N is the total point in the point set.
5. The method for detecting eccentricity of a railway line bridge according to claim 1, wherein the step of measuring the relative position of the beam edge and the on-line structure at the cross section in S2 is as follows: S251, denoising the point cloud, namely removing outlier noise points in the 2D point cloud by using statistical filtering or radius filtering; S252, point cloud classification, namely separating left and right guardrail point clouds by dividing operation by taking the design distance and the height difference of the guardrail relative to the track as space threshold values, and separating left and right rail point clouds by dividing operation by taking the line spacing design value and the clinical line height difference design value as space threshold values; s253, performing cluster analysis, namely performing DBSCAN clustering on the guardrail point cloud, and further extracting the point cloud of the guardrail and the steel rail; s254, performing guardrail top point cloud fitting, namely performing straight line fitting on the guardrail top point cloud to obtain a left guardrail top coordinate Top coordinates of right guard rail ; And S255, calculating the relative position from the line center to the guardrail, namely respectively extracting the coordinates of the center point of the line steel rail through a geometric characteristic method or a template matching method, and calculating the relative position from the line center to the guardrail.
6. The method for detecting eccentricity of a railway line bridge according to claim 5, wherein when calculating the relative position of the center of the line to the guardrail in step S255: For a single-wire bridge, mileage is extracted first Center point of left rail of line at cross section Center point of right rail of line Calculating the distance from the centers of the left and right steel rails to the guard rail And the difference in height 、 The formula is as follows: wherein X L ,Y L ,X R ,Y R is the abscissa and the ordinate of the top coordinates of the left guardrail and the right guardrail respectively; for a two-wire bridge, first extract Left rail center point of left line at cross section Center point of left line and right rail Center point of right line left rail Center point of right rail Measuring the distance from the centers of the left and right lines to the guard rail And And a height difference And The formula is as follows:
7. the railway line bridge eccentricity detection method according to claim 6, wherein: The step of designing the unmanned aerial vehicle route in the S3 is as follows: s311, calculating an outer expansion parallel path: And (2) calculating the normal vector direction of each centerline node according to the geometric parameters of the track measured in the step (S2), and then expanding the centerline nodes outwards by 10 meters to generate parallel paths, wherein the mathematical expression is as follows: ; Wherein the method comprises the steps of Is the coordinate difference of the centerline nodes of adjacent 1m, Coordinates of a midline node; for a railway curve section, the outward expansion direction is adjusted by combining the curvature radius, so that the intersection or abrupt change of paths is avoided; S312, navigational altitude control: unmanned aerial vehicle fly height Should be higher than the elevation of the rail surface Low and low , 3-5 Meters, which comprises: ; if the route passes through the obstacle in the flight process, the height or the transverse offset should be dynamically adjusted to ensure the safety distance; S313, optimizing the route; the relative positions of the beam edges and the in-line structure at the cross section are measured as follows: S351, denoising the point cloud, namely removing outlier noise points in the 2D point cloud by using statistical filtering or radius filtering; s352, classifying point clouds, namely selecting a proper threshold value according to the top coordinates of the left guardrail and the right guardrail measured in the S2, and separating the left guardrail point cloud and the right guardrail point cloud through a segmentation operation; s353, clustering, namely clustering the guardrail point clouds, and further extracting the point clouds of the edges of the guardrails and the beams; S354, fitting the point cloud at the top of the guardrail, namely performing straight line fitting on the point cloud at the top of the guardrail to obtain the top coordinate of the left guardrail Top coordinates of right guard rail Extracting the top corner point of the beam edge based on a straight line fitting method, and obtaining the coordinates of the top corner point of the left beam edge Corner coordinates of top of right beam edge ; S355, calculating the relative position from the top corner point of the beam edge to the guardrail, namely extracting mileage Flat distance between top of left guard rail and left beam edge of cross section of position And the difference in height Flat distance between top of right guard rail and edge of right beam And the difference in height Distance between left and right beam edges of bridge : 。
8. The method of claim 5, wherein the track line data in S3 includes in-flight position (X, Y, Z) and attitude data, and the laser data includes time-synchronized ranging values and scan angles; and calculating global coordinates of each point in the three-dimensional point cloud according to the path line data of the unmanned aerial vehicle, the calibration values of the laser radar and the POS system and the laser data, and finally generating the three-dimensional point cloud outside the bridge.
9. The method for detecting the eccentricity of a railway line bridge according to claim 1, wherein the measured value of the eccentricity of the line bridge in S4 is obtained by performing data fusion according to the data of the relative positions of the track at the cross section and the on-line structure obtained in S2 and the data of the relative positions of the beam edge at the cross section and the on-line structure obtained in S3, so as to realize high-precision relative measurement of the eccentricity of the line bridge; The measuring line bridge eccentricity value comprises the following conditions: (1) For a single-line bridge straight line segment, the line bridge eccentricity P is shown as follows: ; Wherein, the And The distances from the centers of the left steel rail and the right steel rail to the guardrails measured in the step S255 are respectively; As the distance from the left rail top to the left beam edge measured in S355, The distance between the top of the right guardrail and the edge of the right beam measured in S355; (2) For a single-line bridge curve section, the influence of initial eccentricity is required to be considered, an initial eccentricity phenomenon is generated because a bridge plane is a fold line, a line design center line is not overlapped with a beam span design center line, the initial eccentricity phenomenon is generated at the positions of the middle point and the two ends of the beam span, the line bridge eccentricity P is shown in the following formula according to the principle that the center line bisects the chord length (equal to the center distance of a bridge pier or the breast wall surface of a bridge abutment to the center of the bridge) of the center line of the bridge according to the planar arrangement of the upper beam of the curve in a design drawing: ; Wherein, the And The distances from the centers of the left steel rail and the right steel rail to the guardrails measured in the step S255 are respectively; As the distance from the left rail top to the left beam edge measured in S355, The distance between the top of the right guardrail and the edge of the right beam measured in S355; In order to be a track gauge, the track gauge, The bridge pier is ultrahigh, the value of which can be obtained by measuring geometric parameters in the track in S21, wherein L is the center distance of the bridge pier or the distance from the breast wall surface of the bridge abutment to the center of the bridge pier, and the bridge length can be approximately taken; (3) For the straight line segment of the double-line bridge, the design center line of the left and right line lines coincides with the design center line of the left and right beam spans (the line facing the left side of the large mileage is the left line), the actual distance from the line center line to the edge of the beam is measured, and then the actual distance from the design center line of the beam spans to the edge of the beam is compared with the distance from the design center line of the beam spans to the edge of the beam, the line bridge eccentric values of the left and right lines are calculated respectively And The following formula is shown: ; ; Wherein, the And The distances from the centers of the left steel rail and the right steel rail to the guardrails measured in the step S255 are respectively; As the distance from the left rail top to the left beam edge measured in S355, The distance between the top of the right guardrail and the edge of the right beam measured in S355; as the track gauge, in S21 the track internal geometry measurements are available; for the design distance from the center of the left line to the left beam edge, The design distance from the center of the right line to the edge of the right beam is obtained through design data; (4) For the curve section of the double-line bridge, considering the influence of initial eccentricity, calculating the eccentric values of the left and right lines And The following formula is shown: ;
10. The railway line bridge eccentricity detection method according to any one of claims 1 to 9, wherein in S1: The method comprises the steps of arranging GNSS reference stations in a form of GNSS continuous operation reference stations or GNSS temporary stations in a plane control network, wherein the interval between the GNSS reference stations is 15-25 km, arranging a GNSS encryption point at the middle position of the GNSS reference stations with the interval of more than 18km, and calculating the plane coordinates of the encryption point by the GNSS encryption point joint measurement plane control network; The elevation control network is tested according to four equal level measurement standards and is in the same point with GNSS of the plane control network as far as possible, wherein the distance between all elevation points is controlled to be about 4km, elevation encryption control points are arranged for paragraphs with the distance being greater than 4km, and the all-line elevation control points and the high Cheng Jiami control points are measured by adopting the four equal level measurement standards and are combined with high-level control points with known elevations along the line.

Description

Method for detecting eccentricity of railway line bridge by air-rail cooperation Technical Field The invention relates to the technical field of railway work, in particular to a method for detecting the eccentricity of a railway line bridge by utilizing air-rail cooperation. Background The eccentricity of the railway line bridge refers to the offset of the actual center line of the railway line and the designed center line of the beam body in the horizontal direction under the factors of dynamic load, temperature change, foundation settlement and the like of a railway line and bridge joint (line bridge system). The line bridge eccentricity is the result of multi-factor coupling effects such as improper design pre-eccentricity setting, improper construction process, improper maintenance method in the operation period, degradation of bridge material performance, geological condition influence and the like. Meanwhile, the line bridge eccentric can lead the bridge to bear larger uneven load, and long-term uneven load can lead to fatigue damage and damage of the bridge, threaten transportation safety and increase the workload of bridge repair and maintenance. Therefore, the detection and the correction of the eccentricity of the railway line bridge are very important works in the railway operation and maintenance period. Only if the eccentricity of the bridge is accurately and rapidly detected, the effective correction of the eccentricity of the bridge can be ensured. At present, the method for detecting the eccentricity of the railway line bridge comprises three methods of total station measurement, laser ranging and photogrammetry: 1. The total station measuring method is that total stations are erected at key points of bridges and lines, horizontal distance and elevation difference are synchronously measured, and an eccentric value is calculated by combining design drawings, and the total station measuring method has the advantages of high accuracy (reaching millimeter level), suitability for complex terrains or scenes needing multi-angle measurement, such as curved bridges or ramp sections, and the defects of low efficiency and large workload due to the need of manual point collection. 2. The laser distance measuring method is to utilize a laser distance measuring instrument to directly obtain the distance data of measuring points and to quickly calculate the eccentric value by combining with the positioning mark. The method has high efficiency, is especially suitable for large-span bridges or occasions needing to reduce manual intervention, but has higher requirements on the intensity of ambient light, wherein strong light or fog can influence the precision. In addition, because the rail and the beam edge are not in the same field of view, they cannot be observed at the same time, resulting in poor accuracy. 3. And in the photogrammetry, the high-resolution camera is used for shooting the associated images of the bridge and the line, and the three-dimensional modeling software is used for extracting the space coordinates and analyzing the axis deviation. The method can generate a visual report, is convenient for archiving and remote review, and is commonly used for periodic monitoring or historical data comparison. Photogrammetry is generally used for detecting the relative change of the eccentric of the bridge, and has the defects of high internal data processing capacity, high requirements on measuring personnel and equipment, and excessive cost. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide the method for detecting the eccentricity of the railway line bridge by the aid of the air-rail cooperation, and the method can be used for accurately, efficiently and low-cost detecting the eccentricity of the railway line bridge. The invention further aims to provide an accurate railway ballast thickness detection method. For this purpose, the invention adopts the following technical scheme: a method for detecting eccentricity of a railway line bridge by air-rail cooperation comprises the following steps: S1, establishing a line control network consisting of a plane control network and a height control network; s2, measuring geometric parameters of a track by taking the line control network as a reference, combining calibration values of an inertial navigation center and a laser radar center, calculating track line data of the laser radar center in different sampling time sequences, carrying out mobile three-dimensional scanning on an on-line structure of a railway bridge, fusing the obtained laser scanning data and the track line data into a three-dimensional point cloud of the on-line structure of the railway bridge, converting a track center coordinate into a track mileage, selecting a position of a bridge cross section, extracting the cross section of the position from the three-dimensional point cloud data, and measuring the relative position of a beam ed