A method for measuring geometric parameters and wear of rigid contact network based on point cloud data

Abstract

The present invention discloses a method for measuring the geometric parameters and wear of a rigid contact network based on point cloud data, relating to the field of rail transit technology. The method comprises the following steps: S1, real-time acquisition of contact network point cloud image data, and screening of the bus-conductor point cloud profile area in the contact network point cloud image data; S2, extraction of all bus feature line segments within the bus point cloud profile area; S3, rotational correction of the bus-conductor point cloud profile area; S4, clustering and fitting the conductor point set within the corrected conductor point cloud profile area using the least squares method to obtain a standard circle where the conductor lies and a conductor wear line, and using the standard circle and the wear line to measure and output the contact network geometric parameters and wear. The present invention employs the minimum area method, directional integration, and least squares clustering to eliminate noise interference, resulting in high-precision millimeter-level wear and geometric parameter measurements.

Description

Technical Field

[0001] The present invention relates to the field of rail transportation technology, and more particularly to a method for measuring geometric parameters and wear of a rigid contact network based on point cloud data. Background Art

[0002] Electrified power supply is the primary energy source for urban rail operations in my country. Power lines typically utilize an overhead rigid catenary system, with trains drawing power via onboard pantographs. The quality of current drawn and the lifespan of the pantograph and catenary during operation are directly affected by the geometric parameters and wear of the overhead rigid catenary system.

[0003] To ensure operational safety, rigid catenary systems require monitoring of their geometric parameters and wear. Current monitoring methods rely primarily on manual, fixed-point measurements, which are costly, labor-intensive, time-sensitive, and require limited measurement locations. The ideal monitoring solution would be to design onboard equipment that continuously measures and provides real-time feedback during vehicle operation.

[0004] On-board equipment collects point cloud data from the catenary in real time and uses it to measure the geometric parameters and wear of the rigid catenary, making it an ideal monitoring method. However, processing point cloud data is difficult due to the presence of noise interference, overall busbar profile rotation, and partial distortion during dynamic acquisition. These disturbances are often random and lack regularity, resulting in poor accuracy in geometric parameter and wear measurements. Summary of the Invention

[0005] To overcome the shortcomings of the aforementioned prior art, the present invention discloses a method for measuring the geometric parameters and wear of rigid contact networks based on point cloud data. The method extracts rigid busbars and conductors from the point cloud data of a contact network cross section and measures their geometric parameters and wear. The method employs a minimum area method and directional integral method to extract busbar feature segments from the original point cloud. Furthermore, a rotation correction method is employed, and finally, a least-squares clustering-based geometric parameter and wear measurement method is designed to monitor the geometric parameters and wear of rigid contact networks.

[0006] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0007] A method for measuring geometric parameters and wear of a rigid contact network based on point cloud data comprises the following steps:

[0008] 1. Data Collection

[0009] S1. collecting contact network point cloud image data in real time, and screening out the busbar-conductor point cloud outline area in the contact network point cloud image data;

[0010] Preferably, step S1 includes: using a vehicle-mounted device to collect contact network point cloud image data in real time, wherein the vehicle-mounted device is mounted on the roof of the vehicle, and when the vehicle is moving, the vehicle-mounted device performs point cloud imaging on the contact network according to the structured light imaging principle to obtain the contact network point cloud image data;

[0011] In the contact network point cloud image data, the horizontal coordinate w Indicates the direction of the pull-out value of the bow-catenary contact, the vertical coordinate h Indicates the conductor height direction of the pantograph-catenary contact; in the contact network point cloud image data, the busbar-conductor point cloud contour area is screened out, and the busbar-conductor point cloud contour area includes the busbar point cloud contour area and the conductor point cloud contour area.

[0012] 2. Busbar feature profile extraction

[0013] S2. Based on the minimum area method and the directional integral method, all bus feature line segments in the bus point cloud outline area are extracted, and all bus feature line segments are combined to form the bus feature outline;

[0014] In the present invention, the minimum area method is adopted to control the range of the search area and avoid blind search, which can greatly reduce the number of search steps and suppress noise interference.

[0015] Directional integration can obtain the directed length of the search path in the minimum search area. The validity of the search point can be further judged based on the path length and the length of the fitting line to avoid noise interference.

[0016] Preferably, step S2 comprises the following steps:

[0017] S21. Set the slope range of the straight line in the bus point cloud profile area according to prior knowledge ( -k,k ) and length range ( d min , d max );

[0018] S22. Based on the slope range and length range, use the minimum area method to find the point set that meets the judgment conditions in the bus point cloud outline area. S 1;

[0019] Preferably, in step S22, the minimum area method judgment condition includes: in the bus point cloud outline area, the equation of the straight line perpendicular to the two points is y In the direction of y The distance is less than the distance threshold d m When the number of extracted points is greater than the threshold NWhen , it means that there is a straight line between the two points that meets the judgment condition, and the points that meet the judgment condition form a point set S 1.

[0020] Step S22 includes:

[0021] S221. Randomly select a point as the starting point in the bus point cloud outline area p 1. Search for another point p 2. Determine the point p 1 and point p 2 is the equation of a straight line y , where the point p 1 and point p The distance between 2 d satisfy( d min , d max ),point p 1 and point p 2 is the equation of a straight line y The slope k p1p2 satisfy( -k,k );

[0022] S222, traverse the remaining points in the bus point cloud outline area and extract the points that satisfy the straight line equation y The distance is less than the distance threshold d m The points constitute a point set S 1. Point Set S 1The number of midpoints n Greater than the quantity threshold N .

[0023] The distance d , slope k p1p2 , equation of a straight line y , point set S 1 includes:

[0024]

[0025] in, d for point p 1. Point p The distance between 2, x p1 、 x p2 Points p 1. Point p The horizontal axis of 2, y p1 、 y p2 Pointsp 1. Point p The vertical coordinate of 2, d min 、 d max are the minimum and maximum distances, respectively. k p1p2 is the equation of a line y The slope of k is the slope threshold, b p1p2 is the intercept of the line equation, y 、 x are the ordinate and abscissa of the straight line equation, S 1 is the point set, x p 、 y p for point P The horizontal and vertical coordinates of d m is the distance threshold.

[0026] S23, use the direction integral judgment condition to eliminate the interference of the concentrated points in the bus point cloud contour area, and further judge the point set S Whether the discrete degree of the points in 1 meets the requirements, if so, the point set S The points in 1 are fitted into a straight line, the slope and intercept of the fitted line are obtained, and the fitted line is used as the characteristic line segment of the busbar;

[0027] Preferably, step S23 includes: S The distance between adjacent points in 1 is integrated in the direction, and the result of the direction integration is judged to see whether it meets the direction integration judgment condition. If it meets the condition, the point set is S 1 is considered as a discrete set of points on a line in space, and the point set S The points in 1 are fitted into a straight line, and the slope and intercept of the fitted line are obtained.

[0028] Preferably, in step S23, the directional integral, directional integral judgment condition, slope and intercept of the fitting line include:

[0029]

[0030] in, d cal is the directional integral, n Point set S 1The number of midpoints, d i Point set S The distance between adjacent points in 1, p is the ratio, d for point p 1. Pointp 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 Point sets S 1. The horizontal and vertical coordinates of the point.

[0031] S24. Repeat steps S21-S23 to traverse all points in the bus point cloud outline area to obtain all bus feature line segments in the bus point cloud outline area, and eliminate isolated line segments in the bus feature line segments according to the spatial symmetry relationship of the bus to obtain the bus feature outline.

[0032] 3. Rotation Correction

[0033] S3. performing rotation correction on the busbar-conductor point cloud contour area based on the busbar feature line segments in the busbar feature contour;

[0034] Preferably, step S3 includes: using two bus feature line segments in the bus feature profile close to the wire point cloud profile area as the rotation correction baseline of the bus, rotating the bus-wire 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.

[0035] In this invention, rotation correction is performed on the busbar-conductor point cloud profile area because profile rotation is often caused by factors such as vehicle sway or camera distortion, causing contact points and wear locations to deviate from their actual positions, resulting in significant errors in measurement accuracy. Rotation correction improves measurement accuracy and, while achieving near-left-right symmetry, simplifies subsequent wear measurement.

[0036] 4. Measuring geometric parameters and wear measurement

[0037] S4. Cluster and fit the wire point set in the corrected wire point cloud contour area using the least squares method to obtain the standard circle where the wire is located and the wire wear line. The standard circle and the wear line are used to measure the contact network geometric parameters and wear and output them.

[0038] In the present invention, the least squares method is used for fitting to find the center and radius of the circle, and the noise is quickly suppressed by setting the threshold value to locate the point cloud data closest to the actual wire profile, thereby reducing the error caused by noise disturbance.

[0039] 4.1 Least Squares Arc Point Cloud Clustering

[0040] Preferably, in step S4, obtaining the standard circle where the wire is located includes:

[0041] S411, using the least squares method, the wire point set S The arc points in are fitted into a circle;

[0042] Step S411 includes:

[0043]

[0044] in, f is the least squares method, x c ´、 y c ' are the horizontal and vertical coordinates of the center of the fitted circle, 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 horizontal and vertical coordinates of the arc points in the wire point concentration, S 1 is the arc point in the wire point concentration.

[0045] S412, the wire point set S Among the arc points, the distance to the center of the fitting circle is greater than ( r ´+ g ) or less than ( r ´- g ) points are removed, where r ´ is the radius of the fitted circle, g Adjust the threshold;

[0046] S413, loop S411-S412 steps until the wire point set S All arc points in the circle satisfy the distance from the center of the fitting circle in the interval [ r ´- g , r ´+ g ], obtain the standard circle.

[0047] 4.2 Least Squares Linear Point Cloud Clustering

[0048] Preferably, in step S4, obtaining the wire wear straight line includes:

[0049] S421, using the least squares method, the wire point set S The straight line points in the l ;

[0050] Step S421 includes:

[0051]

[0052] in, f is the least squares method, k ´、 b ' are straight lines l The slope and intercept of n is the number of straight line points in the traverse point set, x i 、 y i They are the horizontal and vertical coordinates of the straight line points in the wire point set respectively.

[0053] S422、Set the wire point S The straight line point in the middle, to the straight line l Remove the straight line points whose distance is greater than the threshold;

[0054] S423, loop S421-S422 steps until the wire point set S All the straight line points in the l If the distance is less than or equal to the threshold, the straight line l As a straight line of wear.

[0055] 4.3 Measuring geometric parameters and wear based on standard circle and fitting line

[0056] Preferably, in step S4, the use of the standard circle and the wear line to measure the contact network geometric parameters and wear includes: finding the intersection of the standard circle and the wear line A 、 B , and using the intersection A 、 B Calculate the wear chord length d AB and geometric parameters ( x C , y C ).

[0057] In the present invention, the geometric parameter is the pantograph-catenary contact point, and the present invention uses the midpoint of the wear position as the pantograph-catenary contact point.

[0058] In step S4, the wear chord length d AB and geometric parameters ( x C , y C )include:

[0059]

[0060] in, d AB is the wear chord length, x A、 x B Points A ,point B The horizontal axis, y A 、 y B Points A ,point B The vertical coordinate, x C is the horizontal coordinate of the pantograph-catenary contact point, y C is the vertical coordinate of the pantograph-catenary contact point.

[0061] In the present invention, the wear chord length and the horizontal and vertical coordinates of the pantograph-catenary contact point are obtained.

[0062] The subsequent system monitors the wear chord length and, based on vehicle positioning information, can provide real-time feedback on the degree of contact network wear at different points along the line. When an anomaly is detected, a real-time alarm is issued to remind relevant departments to conduct timely maintenance and reduce unnecessary wear on the line. At the same time, by collecting a large amount of line wear data and analyzing the line wear characteristics, the line is optimized.

[0063] By monitoring the horizontal and vertical coordinates of the pantograph-catenary contact points, the points on the line can be continuously measured. When the geometric parameters are detected to deviate from the design values, an alarm can be issued for confirmation and maintenance to reduce the probability of safety accidents.

[0064] Beneficial effects of the present invention:

[0065] 1. This invention extracts rigid busbars and conductors from contact network cross-section point cloud data and measures their geometric parameters and wear. This invention employs the minimum area method and directional integral method to extract busbar feature segments from the original point cloud, eliminating busbar distortion and interference. A rotation correction method is further designed to correct busbar-conductor rotation. Finally, a least-squares clustering-based geometric parameter and wear measurement method is designed to avoid interference while improving accuracy.

[0066] 2. The vehicle-mounted point cloud acquisition equipment of the present invention is suitable for large-scale automated measurement and has high efficiency. It adopts the minimum area method, directional integration and least squares clustering to eliminate noise interference, so that the measured wear and geometric parameters have an accuracy of millimeter level and have high precision. It has good objectivity and repeatability and is not affected by human factors. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 The present invention method process;

[0068] Figure 2 This is the point cloud outline of the “busbar-conductor” of the present invention;

[0069] Figure 3 This is a schematic diagram of rotation + distortion + noise in the point cloud data anomaly of the present invention;

[0070] Figure 4 This is a schematic diagram of noise interference in point cloud data anomalies in the present invention. Figure 1 ;

[0071] Figure 5 This is a schematic diagram of noise interference in point cloud data anomalies in the present invention. Figure 2 ;

[0072] Figure 6 This is a schematic diagram of the profile search of the present invention;

[0073] Figure 7 This is a schematic diagram of the minimum area and directional integration of the present invention;

[0074] Figure 8 This is a schematic diagram of the characteristic linear rotation correction of the present invention;

[0075] Figure 9 This is a schematic diagram of the rotation correction result of the present invention;

[0076] Figure 10 Schematic diagram of the worn string length and the contact point of the bow and catenary according to the present invention. DETAILED DESCRIPTION

[0077] The following will provide a clear and complete description of the concept, specific structure and technical effects of the present invention in conjunction with the embodiments and drawings, so as to fully understand the purpose, features and effects of the present invention.

[0078] Example 1

[0079] A method for measuring geometric parameters and wear of rigid contact network based on point cloud data, such as Figure 1 As shown, the following steps are included:

[0080] S1. collecting contact network point cloud image data in real time, and screening out the busbar-conductor point cloud outline area in the contact network point cloud image data;

[0081] S2. Based on the minimum area method and the directional integral method, all bus feature line segments in the bus point cloud outline area are extracted, and all bus feature line segments are combined to form the bus feature outline;

[0082] S3. performing rotation correction on the busbar-conductor point cloud contour area based on the busbar feature line segments in the busbar feature contour;

[0083] S4. Cluster and fit the wire point set in the corrected wire point cloud contour area using the least squares method to obtain the standard circle where the wire is located and the wire wear line. The standard circle and the wear line are used to measure the contact network geometric parameters and wear and output them.

[0084] The main steps of this embodiment are as follows:

[0085] (1) Analysis of on-board rigid catenary point cloud data. Difficulties include: 1) Interference and rotation make it impossible to find the correct pantograph-catenary contact point; 2) The measurement of geometric parameters and wear must achieve millimeter-level accuracy. Based on the accuracy of current point cloud equipment, disturbances of more than three points will result in an error of more than 1mm.

[0086] (2) Extract the point cloud outline of the rigid busbar and extract the busbar feature line segments based on the minimum area method and directional integral method.

[0087] (3) Perform rotation correction on the busbar based on the characteristic line segments.

[0088] (4) Clustering based on the least squares method is used to achieve contact line geometric parameters and wear measurement.

[0089] Example 2

[0090] This embodiment further elaborates on step S1, which analyzes the point cloud data of the vehicle-mounted rigid catenary network. Based on the principle of structured light imaging, the catenary network is imaged using a device mounted on the vehicle roof, which collects point cloud data in real time while the vehicle is in motion. Figure 2 The point cloud silhouette collected by the device.

[0091] from Figure 2 It can be seen that there is a lot of noise interference in the field of view, and the part that really needs attention is the "bus-wire". Figure 2 middle w Indicates the direction of the pull-out value of the pantograph-catenary contact, h Indicates the direction of the bow-catenary contact.

[0092] Ideally, Figure 2 The profile in the image is free of interference, distortion and rotation. In this case, it is easy to measure geometric parameters and wear. However, in actual operating conditions, Figure 3 、 Figure 4 and Figure 5 The situation shown here often occurs, and the original point cloud obtained has various abnormalities, such as distortion, interference, or rotation.

[0093] based on Figure 3 、 Figure 4 and Figure 5 There are the following difficulties in measuring geometric parameters and wear using data from:

[0094] (1) Interference and rotation make it impossible to find the correct pantograph-catenary contact point;

[0095] (2) The measurement of geometric parameters and wear must achieve millimeter-level accuracy. Based on the accuracy of current point cloud equipment, a disturbance of more than 3 points will produce an error of more than 1 mm.

[0096] Based on the above difficulties, the present invention proposes the following solutions: (1) First, the regional method and directional integral method are used 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 disturbance; (3) Perform wear measurement based on the fitting of arcs and line segments.

[0097] Example 3

[0098] This embodiment further elaborates on step S2 based on embodiment 2. Step S2 is the extraction of busbar feature profile based on the minimum area method and the directional integration method.

[0099] like Figure 6 As shown l 1. l 2. l 3. l 4 is the characteristic profile of the busbar, which is theoretically a symmetrical straight line segment of fixed length and is extracted using the minimum area method and line segment integration method.

[0100] 1. Set the slope range of the straight line in the bus point cloud profile area based on prior knowledge ( -k,k ) and length range ( d min , d max );

[0101] 2. Use the minimum area method to determine the conditions and eliminate noise interference, such as Figure 7 As shown, perpendicular to the straight line y in the direction of y 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.

[0102] The specific implementation is:

[0103] (1) Randomly select a point as the starting point in the bus point cloud contour area p 1. Search for another point p 2. Determine the point p 1 and point p 2 is the equation of a straight line y , where the pointp 1 and point p The distance between 2 d satisfy( d min , d max ),point p 1 and point p 2 is the equation of a straight line y The slope k p1p2 satisfy( -k,k );

[0104] (2) Traverse the remaining points in the bus point cloud contour area and extract the points that satisfy the straight line equation y The distance is less than the distance threshold d m The points constitute a point set S 1. Point Set S 1The number of midpoints n Greater than the quantity threshold N .

[0105] distance d , slope k p1p2 , equation of a straight line y , point set S 1 includes:

[0106]

[0107] in, d for point p 1. Point p The distance between 2, x p1 、 x p2 Points p 1. Point p The horizontal axis of 2, y p1 、 y p2 Points p 1. Point p The vertical coordinate of 2, d min 、 d max are the minimum and maximum distances, respectively. k p1p2 is the equation of a line y The slope of k is the slope threshold, b p1p2 is the intercept of the line equation, y 、 xare the ordinate and abscissa of the equation of the line, S 1 is the point set, x p 、 y p for point P The horizontal and vertical coordinates of d m is the distance threshold.

[0108] 3. After the minimum area judgment condition is met, the direction integral judgment condition is used to eliminate the interference of the concentrated points in the bus point cloud contour area, and further judge the point set S Whether the discrete degree of the points in 1 meets the requirements, if so, the point set S The points in 1 are fitted into a straight line, and the slope and intercept of the fitted line are obtained. The fitted line is used as the characteristic line segment of the busbar, specifically including:

[0109] Point Set S The distance between adjacent points in 1 is integrated in the direction, and the result of the direction integration is judged to see whether it meets the direction integration judgment condition. If it meets the condition, the point set is S 1 is considered as a discrete set of points on a line in space, and the point set S The points in 1 are fitted into a straight line, and the slope and intercept of the fitted line are obtained.

[0110] Directional integral, directional integral judgment conditions, slope and intercept of the fitting line include:

[0111]

[0112] in, d cal is the directional integral, n Point set S 1The number of midpoints, d i Point set S The distance between adjacent points in 1, p is the ratio, d for 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 Point sets S 1. The horizontal and vertical coordinates of the point.

[0113] By traversing all points in the space through steps 1, 2, and 3, the interference of isolated point sets can be eliminated, and we can obtain Figure 6 Line segment information in l 1. l 2. l 3. l 4. Such as Figure 4 and Figure 5 There is interference from approximate line segments in , and more implementation segments will be found, such as l 5. l 6……, then exclude isolated line segments based on the spatial symmetry of the busbar.

[0114] Example 4

[0115] This embodiment further elaborates on step S3 based on embodiment 3. Step S3 is to perform rotation correction on the busbar based on the characteristic line segment.

[0116] The obtained in step S2 l 2. l 3 as the baseline for the rotation correction of the busbar, such as Figure 8 After the rotation is completed, l 2. l The slope of 3 satisfies the following formula, and all bus points follow l 2. l 3 together, we get Figure 9 Correction results shown.

[0117]

[0118] in, k l2 Bus segment l The slope of 2, k l3 Bus segment l The slope of 3.

[0119] Example 5

[0120] This embodiment further elaborates on step S4 based on embodiment 4. Step S4 is clustering based on the least squares method to achieve contact line geometric parameters and wear measurement.

[0121] Get the corrected bus point cloud data and l 2 and l The set of points between 3 S Use the least squares method to perform clustering, obtain the arc where the wire is located and the wear chord length, and then obtain the geometric parameters and wear. Figure 9 As shown, S There is interference in the point cloud, and the disturbance of two point clouds will result in an error of more than 1mm. In order to eliminate the error, the present invention adopts fitting and clustering methods to avoid interference while improving accuracy.

[0122] 1. Least squares arc point cloud clustering

[0123] (1) Using the least squares method, the wire point set S The arc points in are fitted into a circle, including:

[0124]

[0125] in, f is the least squares method, x c ´、 y c ' are the horizontal and vertical coordinates of the center of the fitted circle, 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 horizontal and vertical coordinates of the arc points in the wire point concentration, S 1 is the arc point in the wire point concentration.

[0126] (2) Set the wire point set S Among the arc points, the distance to the center of the fitting circle is greater than ( r ´+0.5) or less than ( r ´-0.5) points are removed, where r ´ is the radius of the fitted circle;

[0127] (3) Repeat steps (1) and (2) until the wire point set S All arc points in the circle satisfy the distance from the center of the fitting circle in the interval [ r ´-0.5, r ´+0.5], the standard circle is obtained c .

[0128] 2. Least Squares Linear Point Cloud Clustering

[0129] (1) Using the least squares method, the wire point set S The straight line points in the l ,include:

[0130]

[0131] in, f is the least squares method, k ´、 b ' are straight lines l The slope and intercept of n is the number of straight line points in the traverse point set, x i 、y i They are the horizontal and vertical coordinates of the straight line points in the wire point set respectively.

[0132] (2) Set the wire point set S The straight line point in the middle, to the straight line l The straight line points with a distance greater than 0.25mm are removed;

[0133] S423, loop steps (1) and (2) until the wire point set S All the straight line points in the l The distance is less than or equal to 0.25mm, the straight line l As a straight line of wear.

[0134] 3. Measure geometric parameters and wear based on standard circles and fitting lines.

[0135] After steps 1 and 2, l 2 and l The set of points between 3 S Point fitting to obtain a straight line l and circle c ,like Figure 10 As shown. Find the intersection of the arc and the straight line to get A 、 B , and calculate the wear chord length d AB and geometric parameters ( x C , y C ).

[0136]

[0137] in, d AB is the wear chord length, x A 、 x B Points A ,point B The horizontal axis, y A 、 y B Points A ,point B The vertical coordinate, x C is the horizontal coordinate of the pantograph-catenary contact point, y C is the vertical coordinate of the pantograph-catenary contact point.

[0138] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without departing from the spirit of the present invention. These equivalents or substitutions are all included in the scope defined by the claims of the present invention.

Claims

1. A method for measuring geometric parameters and wear of rigid contact network based on point cloud data, characterized in that: The following steps are involved: S1. collecting contact network point cloud image data in real time, and screening out the busbar-conductor point cloud outline area in the contact network point cloud image data; S2. Based on the minimum area method and the directional integral method, all bus feature line segments in the bus point cloud profile area are extracted. All bus feature line segments are combined to form a bus feature profile, including the following steps: S21. Set the slope range of the straight line in the bus point cloud profile area according to prior knowledge ( -k,k ) and length range ( d min , d max ); S22. Based on the slope range and length range, use the minimum area method to find the point set that meets the judgment conditions in the bus point cloud outline area. S 1; S23, use the direction integral judgment condition to eliminate the interference of the concentrated points in the bus point cloud contour area, and further judge the point set S Whether the discrete degree of the points in 1 meets the requirements, if so, the point set S The points in 1 are fitted into a straight line, the slope and intercept of the fitted line are obtained, and the fitted line is used as the characteristic line segment of the busbar; S24, repeating steps S21-S23, traversing all points in the bus point cloud outline area, obtaining all bus feature line segments in the bus point cloud outline area, and eliminating isolated line segments in the bus feature line segments according to the spatial symmetry relationship of the bus to obtain the bus feature outline; S3. performing rotation correction on the busbar-conductor point cloud contour area based on the busbar feature line segments in the busbar feature contour; S4. Cluster and fit the wire point set in the corrected wire point cloud contour area using the least squares method to obtain the standard circle where the wire is located and the wire wear line. The standard circle and the wear line are used to measure the contact network geometric parameters and wear and output them.

2. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: Step S1 includes: using a vehicle-mounted device to collect contact network point cloud image data in real time, wherein the vehicle-mounted device is mounted on the vehicle roof, and when the vehicle is moving, the vehicle-mounted device performs point cloud imaging of the contact network according to the structured light imaging principle to obtain contact network point cloud image data; In the contact network point cloud image data, the horizontal coordinate w Indicates the direction of the pull-out value of the pantograph-catenary contact, the vertical coordinate h Indicates the conductor height direction of the pantograph-catenary contact; in the contact network point cloud image data, the busbar-conductor point cloud contour area is screened out, and the busbar-conductor point cloud contour area includes the busbar point cloud contour area and the conductor point cloud contour area.

3. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: In step S22, the minimum area method judgment conditions include: in the bus point cloud outline area, the equation of the straight line perpendicular to the two points y In the direction of y The distance is less than the distance threshold d m When the number of extracted points is greater than the threshold N When , it means that there is a straight line between the two points that meets the judgment condition, and the points that meet the judgment condition form a point set S 1; Step S22 includes: S221. Randomly select a point as the starting point in the bus point cloud outline area p 1. Search for another point p 2. Determine the point p 1 and point p 2 is the equation of a straight line y , where the point p 1 and point p The distance between 2 d satisfy( d min , d max ),point p 1 and point p 2 is the equation of a straight line y The slope k p1p2 satisfy( -k,k ); S222, traverse the remaining points in the bus point cloud outline area and extract the points that satisfy the straight line equation y The distance is less than the distance threshold d m The points constitute a point set S 1. Point Set S 1The number of midpoints n Greater than the quantity threshold N ; The distance d , slope k p1p2 , equation of a straight line y , point set S 1 includes: in, d for point p 1. Point p The distance between 2, x p1 、 x p2 Points p 1. Point p The horizontal axis of 2, y p1 、 y p2 Points p 1. Point p The vertical coordinate of 2, d min 、 d max are the minimum and maximum distances, respectively. k p1p2 is the equation of a line y The slope of k is the slope threshold, b p1p2 is the intercept of the line equation, y 、 x are the ordinate and abscissa of the equation of the line, S 1 is the point set, x p 、 y p for point P The horizontal and vertical coordinates of d m is the distance threshold.

4. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: Step S23 includes: S The distance between adjacent points in 1 is integrated in the direction, and the result of the direction integration is judged to see whether it meets the direction integration judgment condition. If it meets the condition, the point set is S 1 is considered as a discrete set of points on a line in space, and the point set S The points in 1 are fitted into a straight line, and the slope and intercept of the fitted line are obtained.

5. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: In step S23, the directional integral, directional integral judgment condition, slope and intercept of the fitting line include: in, d cal is the directional integral, n Point set S 1The number of midpoints, d i Point set S The distance between adjacent points in 1, p is the ratio, d for 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 Point sets S 1. The horizontal and vertical coordinates of the point.

6. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: Step S3 includes: using two bus feature line segments in the bus feature profile close to the wire point cloud profile area as the rotation correction baseline of the bus, rotating the bus-wire 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.

7. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: In step S4, obtaining the standard circle where the conductor is located includes: S411, using the least squares method, the wire point set S The arc points in are fitted into a circle, including: in, f is the least squares method, x c ´、 y c ' are the horizontal and vertical coordinates of the center of the fitted circle, 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 horizontal and vertical coordinates of the arc points in the wire point concentration, S 1 is the arc point where the conductor points are concentrated; S412, the wire point set S Among the arc points, the distance to the center of the fitting circle is greater than ( r ´+ g ) or less than ( r ´- g ) points are removed, where r ´ is the radius of the fitted circle, g Adjust the threshold; S413, loop S411-S412 steps until the wire point set S All arc points in the circle satisfy the distance from the center of the fitting circle in the interval [ r ´- g , r ´+ g ], obtain the standard circle.

8. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: In step S4, obtaining the wire wear straight line includes: S421, using the least squares method, the wire point set S The straight line points in the l ,include: in, f is the least squares method, k ´、 b ' are straight lines l The slope and intercept of n is the number of straight line points in the traverse point set, x i 、 y i are the horizontal and vertical coordinates of the straight line points in the wire point set respectively; S422、Set the wire point S In the straight line point, to the straight line l The straight line points whose distance is greater than the threshold are removed; S423, loop S421-S422 steps until the wire point set S All the straight line points in the l If the distance is less than or equal to the threshold, the straight line l As a straight line of wear.

9. The method for measuring geometric parameters and wear of a rigid contact network based on point cloud data according to claim 1, characterized in that: In step S4, the use of the standard circle and the wear line to measure the contact network geometric parameters and wear includes: finding the intersection of the standard circle and the wear line A 、 B , and using the intersection A 、 B Calculate the wear chord length d AB and geometric parameters ( x C , y C ),include: in, d AB is the wear chord length, x A 、 x B Points A ,point B The horizontal axis, y A 、 y B Points A ,point B The vertical coordinate, x C is the horizontal coordinate of the pantograph-catenary contact point, y C is the vertical coordinate of the pantograph-catenary contact point.

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