Method for measuring geometric parameters and abrasion of rigid contact network based on point cloud data

Abstract

The invention discloses a rigid contact network geometric parameter and abrasion measurement method based on point cloud data, and relates to the technical field of rail transit, and the method comprises the following steps: S1, collecting contact network point cloud image data in real time, and screening out a busbar-conductor point cloud profile area in the contact network point cloud image data; s2, extracting all busbar feature line segments in the busbar point cloud profile area; s3, performing rotation correction on the busbar-conductor point cloud profile area; and S4, clustering and fitting the corrected conductor point set in the conductor point cloud profile area by using a least square method to obtain a standard circle where the conductor is located and a conductor wear straight line, and measuring and outputting geometric parameters and wear of the overhead line system by using the standard circle and the wear straight line. According to the method, the noise interference is eliminated by adopting the minimum region method, the direction integral and the least square clustering, so that the precision of the measured abrasion and geometric parameters reaches the millimeter level, and the precision is high.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit, and more specifically to a method for measuring geometric parameters and wear of a rigid catenary based on point cloud data. Background Art

[0002] Electrified power supply is the most important energy supply mode for urban rail operations in China. The power supply line is usually an overhead rigid catenary, and the vehicle takes power through an on-vehicle pantograph. During operation, the current collection quality and the service life of the pantograph-catenary are directly affected by the geometric parameters and wear of the overhead rigid catenary.

[0003] In order to ensure operation safety, it is necessary to monitor the geometric parameters and wear of the rigid catenary. The current monitoring methods are mostly manual fixed-point measurements, which are costly, labor-intensive, poor in timeliness, and limited in measurement points. The ideal detection scheme is to design on-vehicle equipment to continuously measure and provide real-time feedback during vehicle operation.

[0004] Collecting the pantograph point cloud data in real time by on-vehicle equipment and using the pantograph point cloud data to measure the geometric parameters and wear of the rigid catenary is a relatively ideal monitoring method. However, the difficulty in point cloud data processing lies in that there are noise interferences, overall rotation and partial distortion of the busbar profile in dynamic acquisition. These disturbances are often full of randomness and have no regular pattern to follow, resulting in poor measurement accuracy of geometric parameters and wear. Summary of the Invention

[0005] In order to overcome the defects existing in the above-mentioned prior art, the present invention discloses a method for measuring geometric parameters and wear of a rigid catenary based on point cloud data. The present invention extracts the rigid busbar and conductors from the catenary cross-section point cloud data and measures their geometric parameters and wear. The present invention designs a minimum zone method and a direction integration method to extract the busbar feature line segments in the original point cloud, further designs a rotation correction method, and finally designs a geometric parameter and wear measurement based on least squares clustering, realizing the purpose of monitoring the geometric parameters and wear of the rigid catenary.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is: A method for measuring geometric parameters and wear of a rigid catenary based on point cloud data, comprising the following steps: I. Data Acquisition S1. Collect the catenary point cloud image data in real time, and screen out the busbar-conductor point cloud profile area in the catenary point cloud image data; Preferably, the step S1 includes: collecting the catenary point cloud image data in real time by using on-vehicle equipment, the on-vehicle equipment is assembled on the roof of the vehicle, and during the vehicle traveling process, the on-vehicle equipment performs point cloud imaging on the catenary according to the structured light imaging principle to obtain the catenary point cloud image data; In the contact point cloud image data, the abscissa w represents the pulling value direction of the pantograph-catenary contact, and the ordinate h represents the guiding height direction of the pantograph-catenary contact; in the contact point cloud image data, the busbar-conductor point cloud profile area is screened out, and the busbar-conductor point cloud profile area includes the busbar point cloud profile area and the conductor point cloud profile area.

[0007] II. Extraction of the characteristic profile of the busbar S2. Based on the minimum zone method and the direction integration method, extract all the busbar characteristic line segments in the busbar point cloud profile area, and all the busbar characteristic line segments are combined to form the busbar characteristic profile; In the present invention, the minimum zone method is adopted to control the range of the search area, avoid blind search, and can greatly reduce the search steps and suppress the interference of noise.

[0008] Direction integration can obtain the directed length of the search path in the minimum search area, and further judge the validity of the search points according to the path length and the length of the fitted straight line to avoid noise interference.

[0009] Preferably, step S2 includes the following steps: S21. Set the slope range ( -k, k ) and the length range ( d min , d max ) of the straight lines in the busbar point cloud profile area according to prior knowledge; S22. Based on the slope range and the length range, use the judgment condition of the minimum zone method to find the point set S 1 that meets the judgment condition in the busbar point cloud profile area; Preferably, in step S22, the judgment condition of the minimum zone method includes: in the busbar point cloud profile area, in the direction perpendicular to the straight line equation y formed by two points, extract the points whose distance to the straight line equation y is less than the distance threshold d m . When the number of the extracted points is greater than the quantity threshold N , it indicates that there is a straight line between the two points that meets the judgment condition, and the points that meet the judgment condition form the point set S 1.

[0010] Step S22 includes: S221. Randomly select a point as the starting point p 1 in the busbar point cloud profile area, search for another point p 2, and determine the straight line equation formed by point p 1 and point p 2y , where the point p 1 and the point p The distance between 2 d Satisfies ( d min , d max ); the point p 1 and the point p The linear equation formed by 2 y The slope of k p1p2 Satisfies ( -k, k ); S222. Traverse the remaining points in the busbar point cloud profile area, and extract the points that satisfy the distance to the linear equation y Less than the distance threshold d m The points form a point set S 1, the number of points in the point set S 1 n Is greater than the quantity threshold N .

[0011] The said distance d , slope k p1p2 , linear equation y , point set S 1 includes: Among them, d Is the point p 1, the point p 2, x p1 , x p2 Are respectively the points p 1, the point p 2 abscissas, y p1 , y p2 Are respectively the points p 1, the point p 2 ordinates, d min , d max Are respectively the minimum and maximum values of the distance, k p1p2 Is the slope of the linear equation y , k Is the slope threshold, b p1p2 Is the intercept of the linear equation, y , x Are respectively the ordinate and abscissa of the linear equation, S1 is a point set, x p , y p are the horizontal and vertical coordinates of the point P , and d m is the distance threshold.

[0012] S23. Use the direction integral judgment condition to exclude the interference of concentrated points in the busbar point cloud profile area, and further judge whether the discreteness of the points in the point set S 1 meets the requirements. If it meets the requirements, fit the points in the point set S 1 into a straight line, obtain the slope and intercept of the fitted straight line, and use the fitted straight line as the busbar feature line segment; Preferably, the S23 step includes: performing a direction integral on the distances between adjacent points in the point set S 1, and judging whether the result of the direction integral meets the direction integral judgment condition. If it meets the requirements, consider the point set S 1 as the discrete point set of a certain straight line in space, and fit the points in the point set S 1 into a straight line to obtain the slope and intercept of the fitted straight line.

[0013] Preferably, in the S23 step, the direction integral, the direction integral judgment condition, the slope and intercept of the fitted straight line include: Among them, d cal is the direction integral, n is the number of points in the point set S 1, d i is the distance between adjacent points in the point set S 1, p is the ratio, d is the point p 1, point p 2, p min is the ratio threshold, k ´ is the slope of the fitted straight line, b ´ is the intercept of the fitted straight line, x i and y i are the horizontal and vertical coordinates of the points in the point set S 1, respectively.

[0014] S24. Repeat the S21 - S23 steps to traverse all the points in the busbar point cloud profile area, obtain all the busbar feature line segments in the busbar point cloud profile area, and exclude the isolated line segments in the busbar feature line segments according to the spatial symmetry relationship of the busbar to obtain the busbar feature profile.

[0015] III. Rotation correction S3. Based on the busbar feature line segments in the busbar feature profile, perform rotation correction on the busbar-conductor point cloud profile area; Preferably, the step S3 includes: using the two busbar feature line segments in the busbar feature profile close to the conductor point cloud profile area as the rotation correction baseline of the busbar, and rotating the busbar-conductor point cloud profile area based on the rotation correction baseline so that the sum of the slopes of the two rotated rotation correction baselines is 0.

[0016] In the present invention, the reason for performing rotation correction on the busbar-conductor point cloud profile area is that: the rotation of the profile is usually caused by factors such as vehicle body shaking or camera distortion, resulting in the contact point and wear position deviating from the actual position, and at this time, there will be a large error in the measurement accuracy. After rotation correction, the measurement accuracy can be improved, and the subsequent wear measurement operation can be made simple due to the approximately symmetrical relationship on both sides.

[0017] IV. Measuring geometric parameters and wear measurement S4. Cluster and fit the conductor point set in the corrected conductor point cloud profile area using the least squares method to obtain the standard circle where the conductor is located and the conductor wear line, and measure the catenary geometric parameters and wear using the standard circle and the wear line and output them.

[0018] In the present invention, the least squares method is used for fitting to find the center and radius of the circle, and noise is quickly suppressed by setting a threshold to locate the point cloud data closest to the actual conductor profile, reducing the error caused by noise disturbance.

[0019] 4.1 Least squares method for circular arc point cloud clustering Preferably, in the step S4, the obtaining of the standard circle where the conductor is located includes: S411. Using the least squares method, fit the circular arc points in the conductor point set S into a circle; The step S411 includes: wherein, f is the least squares method, x c ´, y c ´ are the abscissa and ordinate of the center of the fitted circle respectively, r ´ is the radius of the fitted circle, n is the number of circular arc points in the conductor point set, x i , y i are the abscissa and ordinate of the circular arc points in the conductor point set respectively, S1 is the arc point in the set of traverse points.

[0020] S412. Remove the points in the arc points of the set of traverse points whose distances to the center of the fitted circle are greater than ( S ´ + r ´) or less than ( g ´ - r ´), where g ´ is the radius of the fitted circle and r ´ is the adjustment threshold. g Adjust the threshold. S413. Repeat steps S411 - S412 until all the arc points in the set of traverse points S satisfy that the distances to the center of the fitted circle are within the interval r ´ - g , r ´ + g , and obtain the standard circle.

[0021] 4.2 Least Squares Straight Line Point Cloud Clustering Preferably, in step S4, the obtaining of the wire wear straight line includes: S421. Use the least squares method to fit the straight line points in the set of traverse points S into a straight line l ; Step S421 includes: where f is the least squares method, k ´, b ´ are the slope and intercept of the straight line l respectively, n is the number of straight line points in the set of traverse points, x i , y i are the abscissa and ordinate of the straight line points in the set of traverse points respectively.

[0022] S422. Remove the straight line points in the set of traverse points S whose distances to the straight line l are greater than the threshold; S423. Repeat steps S421 - S422 until all the straight line points in the set of traverse points S satisfy that the distances to the straight line l are less than or equal to the threshold, and take the straight line l as the wear straight line.

[0023] 4.3 Measure Geometric Parameters and Wear Based on the Standard Circle and the Fitted Straight Line Preferably, in step S4, the measurement of the catenary geometric parameters and wear using the standard circle and the wear straight line includes: finding the intersection points of the standard circle and the wear straight line A , B , and using the intersection points A , B to calculate the wear chord length d AB and the geometric parameters ( x C , y C ).

[0024] In the present invention, the geometric parameter is the pantograph-catenary contact point, and the midpoint of the wear position is used as the pantograph-catenary contact point in the present invention.

[0025] In step S4, the wear chord length d AB and the geometric parameters ( x C , y C ) include: Among them, d AB is the wear chord length, x A , x B are the abscissas of point A and point B respectively, y A , y B are the ordinates of point A and point B respectively, x C is the abscissa of the pantograph-catenary contact point, y C is the ordinate of the pantograph-catenary contact point.

[0026] In the present invention, the wear chord length and the abscissa and ordinate of the pantograph-catenary contact point are obtained.

[0027] Subsequently, the system can monitor the wear chord length and, according to the vehicle positioning information, can provide real-time feedback on the wear degree of the catenary at different points on the line. When an anomaly is detected, it will give a real-time warning to remind the relevant department to conduct timely maintenance, reducing unnecessary wear on the line; at the same time, by collecting a large amount of line wear data, analyzing the line wear characteristics to optimize the line.

[0028] By monitoring the horizontal and vertical coordinates of the pantograph-catenary contact point, continuous measurement of the points on the line can be carried out. When it is detected that the geometric parameters deviate from the design values, an alarm can be issued for confirmation and maintenance, reducing the probability of safety accidents.

[0029] Advantages of the present invention: 1. In the present invention, the rigid busbar and the conductor are extracted from the catenary cross-section point cloud data, and their geometric parameters and wear are measured. The present invention designs the minimum area method and the direction integration method to extract the busbar feature line segments in the original point cloud, excluding the distortion and interference of the busbar. Further, the rotation correction method is designed to correct the rotation of the busbar-conductor. Finally, the geometric parameters and wear measurement based on the least squares clustering are designed to improve the accuracy while avoiding interference.

[0030] 2. The on-vehicle point cloud acquisition device of the present invention is suitable for large-scale automated measurement and has high efficiency; the minimum area method, direction integration, and least squares clustering are used to exclude noise interference, making the measured wear and geometric parameter accuracy reach the millimeter level, with high precision; objectivity and repeatability are good, and it is not affected by human factors. Description of the drawings

[0031] Figure 1 is the method flow of the present invention; Figure 2 is the point cloud profile of the "busbar-conductor" of the present invention; Figure 3 is the schematic diagram of rotation + distortion + noise in the abnormal point cloud data of the present invention; Figure 4 is the schematic diagram of noise interference in the abnormal point cloud data of the present invention Figure 1 ; Figure 5 is the schematic diagram of noise interference in the abnormal point cloud data of the present invention Figure 2 ; Figure 6 is the schematic diagram of profile search of the present invention; Figure 7 is the schematic diagram of minimum area and direction integration of the present invention; Figure 8 is the schematic diagram of feature line rotation correction of the present invention; Figure 9 is the schematic diagram of rotation correction result of the present invention; Figure 10 is the schematic diagram of wear chord length and pantograph-catenary contact point of the present invention. Detailed implementation manners

[0032] The following will clearly and completely describe the concept, specific structure, and technical effects generated by the present invention in combination with the embodiments and the drawings, so as to fully understand the purpose, features, and effects of the present invention.

[0033] Example 1 A method for measuring geometric parameters and wear of a rigid catenary based on point cloud data, as Figure 1 shown, includes the following steps: S1. Collect the point cloud image data of the catenary contact points in real time, and screen out the bus-bar - conductor point cloud profile area in the point cloud image data of the catenary contact points; S2. Based on the minimum zone method and the direction integral method, extract all the bus-bar feature line segments in the bus-bar point cloud profile area, and the combination of all the bus-bar feature line segments constitutes the bus-bar feature profile; S3. Based on the bus-bar feature line segments in the bus-bar feature profile, perform rotational correction on the bus-bar - conductor point cloud profile area; S4. Use the least squares method to cluster and fit the conductor point set in the corrected conductor point cloud profile area to obtain the standard circle where the conductor is located and the conductor wear line, and measure the geometric parameters and wear of the catenary using the standard circle and the wear line and output them.

[0034] The main steps of this embodiment are as follows: (1) Analysis of on-vehicle rigid catenary contact point cloud data. The following difficulties are included: 1) Interference and rotation make it impossible to find the correct pantograph-catenary contact point; 2) The measurement of geometric parameters and wear should reach the accuracy of millimeters. Based on the accuracy of current point cloud devices, perturbations of more than 3 points will cause an error of more than 1 mm.

[0035] (2) Extract the rigid bus-bar point cloud profile, and based on the minimum zone method and the direction integral method, extract the bus-bar feature line segments.

[0036] (3) Perform rotational correction on the bus-bar based on the feature line segments.

[0037] (4) Realize the measurement of the geometric parameters and wear of the contact wire based on the clustering of the least squares method.

[0038] Example 2 On the basis of Example 1, this embodiment further elaborates on step S1. Step S1 is the analysis of on-vehicle rigid catenary contact point cloud data. According to the principle of structured light imaging, point cloud imaging of the catenary is performed. The device is assembled on the roof of the vehicle, and real-time point cloud collection is carried out during the vehicle's travel. Figure 2 is the point cloud profile collected by the device.

[0039] From Figure 2 it can be seen that there is a large amount of noise interference in the field of view. The part that really needs attention - "bus-bar - conductor", Figure 2 in w represents the pull-out value direction of the pantograph-catenary contact, h represents the conductor height direction of the pantograph-catenary contact.

[0040] Ideally, such as Figure 2 the profile in, without interference, distortion and rotation, in which case it is easy to measure geometric parameters and wear. However, in the actual operating environment, such as Figure 3 , Figure 4 and Figure 5 shown, various abnormal situations often occur in the obtained original point cloud, such as distortion, interference or rotation, etc.

[0041] Based on Figure 3 , Figure 4 and Figure 5 the data in, there are the following difficulties in measuring geometric parameters and wear: (1) Interference and rotation make it impossible to find the correct pantograph-catenary contact point; (2) To measure geometric parameters and wear with an accuracy of millimeters, based on the accuracy of current point cloud devices, perturbations of more than 3 points will result in an error of more than 1 mm.

[0042] Based on the above difficulties, the present invention proposes the following solutions: (1) First, use the region method and the direction integration method to extract the characteristic line segments of the busbar - Figure 6 in l 1, l 2, l 3, l 4, and remove interference; (2) Correct according to the geometric relationship of the profile in space to eliminate rotational perturbations; (3) Based on the fitting of arcs and line segments, conduct wear measurement.

[0043] Embodiment 3 Based on Embodiment 2, this embodiment further elaborates on step S2. Step S2 is the extraction of the characteristic profile of the busbar based on the minimum region method and the direction integration method.

[0044] Such as Figure 6 shown, take l 1, l 2, l 3, l 4 as the characteristic profile of the busbar, which is theoretically a straight line segment with a fixed length and symmetry, and is extracted using the minimum region method and the line segment integration method.

[0045] 1. Set the slope range ( -k, k ) and the length range ( d min , d max ) of the straight line in the profile area of the busbar point cloud according to prior knowledge; 2. Use the minimum region method to judge the conditions to exclude noise interference. As Figure 7 shown, in the direction perpendicular to the straight line y and toy The distance is less than d m the number of points is greater than the threshold N , indicating that there may be a straight line between the two points.

[0046] The specific implementation is as follows: (1) In the busbar point cloud profile area, randomly select a point as the starting point p 1, search for another point p 2, determine the point p 1 and the point p 2 to form the straight line equation y , where the point p 1 and the point p 2 the distance between d satisfies ( d min , d max ), the point p 1 and the point p 2 to form the straight line equation y the slope of k p1p2 satisfies ( -k, k ); (2) Traverse the remaining points in the busbar point cloud profile area, and extract the points that satisfy the distance to the straight line equation y is less than the distance threshold d m to form a point set S 1, the number of points in the point set S 1 n is greater than the quantity threshold N .

[0047] Distance d , slope k p1p2 , straight line equation y , point set S 1 includes: Among them, d is the point p 1, point p 2 the distance between, x p1 , x p2 are respectively the points p 1, point p 2 abscissas, y p1 , y p2 are respectively the points p 1, point p 2 ordinates,d min , d max are the minimum and maximum values of the distance, respectively, k p1p2 is the straight-line equation y of the slope, k is the slope threshold, b p1p2 is the intercept of the straight-line equation, y , x are the ordinate and abscissa of the straight-line equation, respectively, S 1 is a point set, x p , y p is a point P of the abscissa and ordinate, d m is the distance threshold.

[0048] 3. After satisfying the minimum area judgment condition, use the direction integral judgment condition to exclude the interference of concentrated points in the busbar point cloud profile area, and further judge whether the discreteness of the points in the point set S 1 meets the requirement. If it meets, fit the points in the point set S 1 into a straight line, obtain the slope and intercept of the fitted straight line, and use the fitted straight line as the busbar feature line segment, specifically including: Perform a direction integral on the distances between adjacent points in the point set S 1, and judge whether the result of the direction integral meets the direction integral judgment condition. If it meets, regard the point set S 1 as a discrete point set of a certain straight line in space, and fit the points in the point set S 1 into a straight line to obtain the slope and intercept of the fitted straight line.

[0049] The direction integral, the direction integral judgment condition, the slope and intercept of the fitted straight line include: Among them, d cal is the direction integral, n is the number of points in the point set S 1, d i is the distance between adjacent points in the point set S 1, p is the ratio, d is the point p 1, point p 2, p min is the ratio threshold, k ´ is the slope of the fitted straight line, b´ is the intercept of the fitting line, x i and y i are the abscissa and ordinate of the points in the point set S 1 respectively.

[0050] By traversing all the points in the space through steps 1, 2, and 3, the interference of the isolated point set can be excluded, and the Figure 6 line segment information in l 1, l 2, l 3, l 4 can be obtained. For example, there is interference from approximate line segments in Figure 4 and Figure 5 , and more implementation segments will be found, such as l 5, l 6... Then, the isolated line segments are excluded according to the spatial symmetry relationship of the busbar.

[0051] Embodiment 4 Based on Embodiment 3, this embodiment further elaborates on step S3. Step S3 is to perform rotational correction on the busbar based on the characteristic line segment.

[0052] Take the l 2, l 3 obtained in step S2 as the baseline for the rotational correction of the busbar. Rotate as shown in Figure 8 . After the rotation is completed, the slopes of l 2, l 3 satisfy the following formula, and all the points of the busbar rotate together with the rotation angle of l 2, l 3 to obtain the correction result as shown in Figure 9 .

[0053] Among them, k l2 is the slope of the busbar line segment l 2, k l3 is the slope of the busbar line segment l 3.

[0054] Embodiment 5 Based on Embodiment 4, this embodiment further elaborates on step S4. Step S4 is clustering based on the least squares method to realize the measurement of the geometric parameters and wear of the contact line.

[0055] After obtaining the corrected busbar point cloud data, the point set l between 2 and l 3 SClustering is performed using the least squares method to obtain the arc where the wire is located and the worn chord length, and then geometric parameters and wear are obtained. As Figure 9 shown, S there are interferences, and the perturbation of two point clouds will result in an error exceeding 1 mm. To eliminate the error, the present invention adopts the methods of fitting and clustering to improve the accuracy while avoiding interferences.

[0056] 1. Least Squares Method for Arc Point Cloud Clustering (1) Using the least squares method, fit the arc points in the wire point set S into a circle, including: where, f is the least squares method, x c ´, y c ´ are the abscissa and ordinate of the center of the fitted circle respectively, r ´ is the radius of the fitted circle, n is the number of arc points in the wire point set, x i , y i are the abscissa and ordinate of the arc points in the wire point set respectively, S 1 is the arc point in the wire point set.

[0057] (2) Among the arc points in the wire point set S , remove the points whose distance to the center of the fitted circle is greater than ( r ´ + 0.5) or less than ( r ´ - 0.5), where r ´ is the radius of the fitted circle; (3) Loop steps (1) and (2) until all the arc points in the wire point set S satisfy that the distance to the center of the fitted circle is in the interval r ´ - 0.5, r ´ + 0.5], and obtain the standard circle c .

[0058] 2. Least Squares Method for Line Point Cloud Clustering (1) Using the least squares method, fit the line points in the wire point set S into a line l , including: where, f is the least squares method, k ´, b ´ are the slope and intercept of the line l respectively, nis the number of straight-line points in the wire point set, x i 、 y i are the abscissa and ordinate of the straight-line points in the wire point set respectively.

[0059] (2)Remove the straight-line points in the wire point set S whose distance to the straight line l is greater than 0.25 mm; S423. Loop through steps (1) and (2) until all the straight-line points in the wire point set S satisfy that the distance to the straight line l is less than or equal to 0.25 mm, and take the straight line l as the worn straight line.

[0060] 3. Measure geometric parameters and wear based on the standard circle and the fitted straight line.

[0061] After steps 1 and 2, fit the point set l between 2 and l 3 to obtain the straight line S and the circle l as shown in c . Find the intersection points of the arc and the straight line to obtain Figure 10 , and calculate the wear chord length A 、 B and geometric parameters ( d AB . x C , y C ).

[0062] Among them, d AB is the wear chord length, x A 、 x B are the abscissas of point A and point B respectively, y A 、 y B are the ordinates of point A and point B respectively, x C is the abscissa of the pantograph-catenary contact point, y C is the ordinate of the pantograph-catenary contact point.

[0063] The above has specifically described the embodiments of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalents or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A method for measuring geometric parameters and wear of a rigid catenary based on point cloud data, characterized in that, It includes the following steps: S1. Real-time collect the contact point cloud image data, and screen out the bus-bar - conductor point cloud profile area in the contact point cloud image data; S2. Based on the minimum area method and the direction integration method, extract all the bus-bar feature line segments in the bus-bar point cloud profile area, and the combination of all the bus-bar feature line segments constitutes the bus-bar feature profile; S3. Based on the bus-bar feature line segments in the bus-bar feature profile, perform rotation correction on the bus-bar - conductor point cloud profile area; S4. Use the least square method to cluster and fit the conductor point set in the corrected conductor point cloud profile area to obtain the standard circle where the conductor is located and the conductor wear straight line, and measure and output the catenary geometric parameters and wear using the standard circle and the wear straight line.

2. The method for measuring the geometric parameters and wear of a rigid catenary based on point cloud data according to claim 1, wherein, Step S1 includes: Using on-vehicle equipment to real-time collect the contact point cloud image data. The on-vehicle equipment is assembled on the roof of the vehicle. During the vehicle's travel, the on-vehicle equipment performs point cloud imaging on the catenary according to the structured light imaging principle to obtain the contact point cloud image data; In the contact point cloud image data, the abscissa w represents the pulling value direction of the pantograph-catenary contact, and the ordinate h represents the guide height direction of the pantograph-catenary contact; in the contact point cloud image data, the bus-bar - conductor point cloud profile area is screened out, and the bus-bar - conductor point cloud profile area includes the bus-bar point cloud profile area and the conductor point cloud profile area.

3. The geometric parameter and wear measurement method of a rigid catenary based on point cloud data according to claim 1, characterized in that, Step S2 includes the following steps: S21. Set the slope range ( -k,k ) and the length range ( d min , d max ) of the straight lines in the busbar point cloud profile area according to prior knowledge; S22. Based on the slope range and length range, use the minimum zone method to determine the condition and find the point set that meets the determination condition in the busbar point cloud profile area S 1; S23. Use the direction integral judgment condition to exclude the interference of concentrated points in the busbar point cloud profile area, and further judge whether the discreteness of the points in point set S 1 meets the requirements. If it meets the requirements, then fit the points in point set S 1 into a straight line, obtain the slope and intercept of the fitted straight line, and use the fitted straight line as the busbar feature line segment; S24. Repeat steps S21 - S23, traverse all the points in the bus-bar point cloud profile area, obtain all the bus-bar feature line segments in the bus-bar point cloud profile area, and exclude the isolated line segments in the bus-bar feature line segments according to the spatial symmetry relationship of the bus-bar to obtain the bus-bar feature profile.

4. The method for measuring the geometric parameters and wear of a rigid catenary based on point cloud data according to claim 3, characterized in that In step S22, the determination conditions of the minimum area method include: in the busbar point cloud profile region, in the direction perpendicular to the straight line equation formed by two points y , the points whose distance to the straight line equation y is less than the distance threshold d m are extracted. When the number of extracted points is greater than the quantity threshold N , it indicates that there is a straight line between the two points that meets the determination conditions, and the points that meet the determination conditions form a point set S 1. Step S22 includes: S221. Randomly select a point as the starting point in the busbar point cloud profile area p 1. Search for another point p 2. Determine the point p 1 and the point p 2 to form the straight-line equation y , where the point p 1 and the point p 2 between the distances d satisfy ([[]] d min , d max ), the point p 1 and the point p 2 to form the straight-line equation y of the slope k p1p2 satisfy ([[]] -k,k ); S222. Traverse the remaining points in the busbar point cloud profile area, and extract the points that satisfy the distance to the straight line equation y is less than the distance threshold d m to form a point set S 1. The number of points in the point set S is greater than the quantity threshold n ; N ; The said distance d , slope k p1p2 , linear equation y , point set S 1 includes: Among them, d is the point p 1. The distance between point p 2, x p1 , x p2 are respectively the abscissas of point p 1 and point p 2, y p1 , y p2 are respectively the ordinates of point p 1 and point p 2, d min , d max are respectively the minimum and maximum values of the distance, k p1p2 is the slope of the straight line equation y , k is the slope threshold, b p1p2 is the intercept of the straight line equation, y , x are respectively the ordinate and abscissa of the straight line equation, S 1 is a point set, x p , y p are the abscissa and ordinate of point P , d m is the distance threshold.

5. The method for measuring the geometric parameters and wear of a rigid catenary based on point cloud data according to claim 3, characterized in that Step S23 includes: performing a directional integration on the distances between adjacent points in point set S 1, and determining whether the result of the directional integration meets the directional integration determination condition. If it meets, consider point set S 1 as the discrete point set of a certain straight line in space, and fitting the points in point set S 1 into a straight line to obtain the slope and intercept of the fitted straight line.

6. The method for measuring geometric parameters and wear of a rigid catenary based on point cloud data according to claim 5, characterized in that, In step S23, the direction integration, the direction integration judgment condition, the slope and intercept of the fitted straight line include: Among them, d cal is the directional integral, n is the point set S the number of points in 1, d i is the point set S the distance between adjacent points in 1, p is the ratio, d is the point p 1, point p the distance between 2, p min is the ratio threshold, k ´ is the slope of the fitted line, b ´ is the intercept of the fitted line, x i and y i are respectively the abscissa and ordinate of the points in the point set S 1.

7. The method for measuring the geometric parameters and wear of a rigid catenary based on point cloud data according to claim 1, characterized in that, Step S3 includes: Use the two bus-bar feature line segments close to the conductor point cloud profile area in the bus-bar feature profile as the rotation correction baseline of the bus-bar, and rotate the bus-bar - conductor point cloud profile area based on the rotation correction baseline so that the sum of the slopes of the two rotated rotation correction baselines is 0.

8. A method for measuring geometric parameters and wear of a rigid catenary based on point cloud data according to claim 1, characterized in that, In step S4, the obtaining of the standard circle where the conductor is located includes: S411. Using the least squares method, fitting the arc points in the wire point set S into a circle, including: Among them, f is the least squares method, x c ´, y c ´ are the abscissa and ordinate of the center of the fitted circle respectively, r ´ is the radius of the fitted circle, n is the number of arc points in the set of traverse points, x i 、 y i are the abscissa and ordinate of the arc points in the set of traverse points respectively, S 1 is the arc point in the set of traverse points; S412. Remove the points in the arc points of the wire point set S whose distance to the center of the fitted circle is greater than ( r ´ + g ) or less than ( r ´ - g ), where r ´ is the radius of the fitted circle, and g is the adjustment threshold. S413. Repeat the steps of S411 - S412 until all the circular arc points in the wire point set S satisfy that the distance to the center of the fitted circle is within the interval r ´ - g , r ´ + g , and obtain the standard circle.

9. The method for measuring the geometric parameters and wear of a rigid catenary based on point cloud data according to claim 1, characterized in that In step S4, the obtaining of the conductor wear straight line includes: S421. Using the least squares method, fitting the straight line points in the wire point set S into a straight line l , including: Among them, f is the least squares method, k ´, b ´ are the slope and intercept of the straight line l respectively, n is the number of straight line points in the set of traverse points, x i , y i are the abscissa and ordinate of the straight line points in the set of traverse points respectively; S422. Remove the straight-line points in the set of wire points S whose distances to the straight line l are greater than the threshold value. S423. Repeat the steps of S421 - S422 until all the straight - line points in the wire point set S satisfy that the distance to the straight line l is less than or equal to the threshold value, and regard the straight line l as the worn - out straight line.

10. A method for measuring geometric parameters and wear of a rigid catenary based on point cloud data according to claim 1, characterized in that, In step S4, the measurement of the catenary geometric parameters and wear using the standard circle and the wear straight line includes: finding the intersection points of the standard circle and the wear straight line A , B , and using the intersection points A , B to calculate the wear chord length d AB and geometric parameters ( x C , y C ), including: Among them, d AB is the wear chord length, x A and x B are the abscissas of points A and B respectively, y A and y B are the ordinates of points A and B respectively, x C is the abscissa of the pantograph-catenary contact point, y C is the ordinate of the pantograph-catenary contact point.

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