A catenary wear measurement method of an overhead line intelligent inspection robot
By collecting point cloud data and performing profile matching through an intelligent contact wire inspection robot, the problems of time-consuming, labor-intensive, and inaccurate traditional contact wire wear measurement have been solved, achieving efficient and accurate wear detection that is adaptable to contact wires of different shapes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTHWEST JIAOTONG UNIV
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-29
AI Technical Summary
Existing methods for measuring contact wire wear are time-consuming and labor-intensive, and their accuracy is insufficient for non-standard circular contact wires. They are also unable to adapt to complex working conditions and have poor robustness.
The system uses an intelligent contact network inspection robot to collect point cloud data, extracts the contact line point cloud profile using 3D structured light imaging equipment, and measures wear by matching the profile. It is applicable to both standard and non-standard circular contact lines.
It achieves efficient and accurate contact wire wear detection, saves manpower and time costs, adapts to contact wires of different shapes, and improves the automation and real-time performance of the detection.
Smart Images
Figure CN122107989A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of flexible contact network point cloud data processing and flexible contact network wear measurement technology, and more specifically to a method for measuring contact wire wear of an intelligent contact network inspection robot. Background Technology
[0002] As the operating time of high-speed railways increases, equipment wear and aging are becoming increasingly serious. As an indispensable component of high-speed railway operation, the safe and stable power supply of overhead contact line equipment is of paramount importance to the daily work of railway power supply professionals.
[0003] As a crucial component of the pantograph-catenary current collection system in high-speed trains, the contact wire must not exhibit any abnormalities during high-speed operation. Severe contact wire wear poses a significant safety hazard to high-speed railway operations. However, contact wire wear measurement is often overlooked in routine maintenance, and scheduling unified measurement windows is time-consuming and labor-intensive. The significance of wear measurement lies in its ability to dynamically monitor equipment hazards, allowing for more targeted planning of key remedial projects and equipment maintenance cycles, thereby achieving the goals of improving quality, reducing costs, and increasing efficiency. With the deepening research into the health system of the overhead contact system, contact wire wear measurement and prediction can serve as an important component, providing data support for "condition-based maintenance of the overhead contact system."
[0004] Existing methods for measuring contact wire wear have several drawbacks. For example, traditional manual point-based inspection methods are time-consuming and labor-intensive, and while ensuring measurement accuracy, they fall short in terms of saving manpower and time costs. Furthermore, some methods are primarily designed based on the assumption that the contact wire surface is a standard circle; they are not applicable to non-standard circular contact wires (such as elliptical or irregular shapes), resulting in poor algorithm versatility. When the wire wear surface is severely uneven or irregular, these methods fail to determine the amount of wear or exhibit significant detection errors, and they lack robustness for detecting wear on flexible contact wires operating under complex conditions. Summary of the Invention
[0005] To overcome the shortcomings of the existing technology, this invention discloses a method for measuring contact wire wear using an intelligent contact wire inspection robot. This invention employs an intelligent contact wire inspection robot equipped with a 3D structured light imaging device to collect raw point cloud data of the flexible contact wire, extract the contact wire point cloud profile from the point cloud data, match the contact wire point cloud profile with the standard contact wire point cloud profile, and measure the contact wire wear based on the matching result. This contact wire wear measurement method based on a 3D structured light camera can effectively replace traditional manual fixed-point inspection for contact wire wear detection, enabling continuous monitoring of changes in contact wire wear. While ensuring measurement accuracy, it saves manpower and time costs, effectively improving work efficiency.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for measuring contact wire wear using an intelligent overhead contact line inspection robot includes the following steps: I. Raw Point Cloud Data Acquisition S1. Collect raw point cloud data of the flexible contact network; Preferably, in step S1, an intelligent inspection robot for the contact network, equipped with a 3D structured light imaging device, is used to collect raw point cloud data of the flexible contact network.
[0007] II. Flexible Contact Line Profile Extraction S2. The arc search method based on noise suppression is used to extract the contact line point cloud profile from the original point cloud data of the flexible contact wire. Preferably, step S2 includes: S21. Set the required search radius range based on prior knowledge. r min , r max ), This represents the minimum search radius. This represents the maximum search radius. Preferably, in step S21, the radius range is:
[0008] in, This represents the minimum search radius. This represents the maximum search radius. This refers to the standard radius of the contact wire in the operating circuit.
[0009] S22. Randomly select 3 points from the original point cloud data of the flexible contact network. A ( x 1, y 1), B ( x 2, y 2) and C ( x 3, y 3) Determine the center of the circle ( x c , y c ) and radius r , where the radius r belong( r min , r max ); Step S22 includes:
[0010]
[0011]
[0012]
[0013]
[0014]
[0015] in, for AB The coordinates of the midpoint; for BC The coordinates of the midpoint; for AB The distance between them; for BC The distance between them; for AB The slope; for BC The slope; For AB Midpoint and AB The slope of a perpendicular line segment; For BC Midpoint and BC The slope of a vertical line segment.
[0016] S23. Traverse the remaining points in the original point cloud data of the flexible contact network and extract them to the center of the circle. x c , y c The distance of ) belongs to the interval (r- ,r+ The points form a point set. S 3. Extract the center of the circle ( x c , y c The distance of ) belongs to the interval (0, r+) The points form a point set. S 4; among which, Preset distance; S24, Determine the point set S 3 and point set S 4. Does the noise suppression condition meet? If so, then the point set... S In point 3, the point represents a segment of an arc and serves as the contact line point cloud outline. S .
[0017] Preferably, in step S24, the noise suppression condition includes: point set S The number of midpoints in 3 is greater than the threshold.n And point set S 3 and point set S 4. The number of elements in the intersection and the set of points S The ratio of the number of elements with a value of 4 is greater than the threshold. p min .
[0018] Step S24 also includes: dividing the point set S By fitting the points in step 3, the center of the circle can be obtained. and radius .
[0019] Step S24 includes:
[0020]
[0021]
[0022]
[0023] III. Silhouette Matching S3. Match the contact line point cloud profile with the corresponding standard contact line point cloud profile in the discrete template library; wherein, the discrete template library includes a variety of standard contact line point cloud profiles of different specifications, and the contact line includes standard circular contact lines and non-standard circular contact lines. Preferably, step S3 includes: S31. Establish a discrete template library containing various standard point cloud profiles of contact wires based on the nominal specifications of the contact wire, and find the standard point cloud profile of the contact wire corresponding to the point cloud profile of the contact wire in the discrete template library. S32. The least squares method is used to fit the points in the contact line point cloud profile to obtain the center O of the fitted circle. and radius R ; Preferably, step S32 includes:
[0024] in, n This indicates the number of points in the contact line point cloud profile; i Indicates the first i One point; Represents the coordinates of a point within the contact line point cloud outline; S This represents the outline of the contact line point cloud.
[0025] S33. Take half of the angle formed by the center O and the left and right endpoints of the contact line point cloud profile as the direction angle of the moving contact line standard point cloud profile. S34. Move the center of the contact line standard point cloud profile along the direction angle, starting from the center of the fitted circle. Stop moving when the average distance between the left and right arc regions in the contact line point cloud profile and the contact line standard point cloud profile is less than the threshold.
[0026] IV. Wear Measurement S4. Measure the wear of the contact line by using the contact line point cloud profile after profile matching and the standard contact line point cloud profile.
[0027] Preferably, step S4 includes: S41. Traverse the contact line point cloud outline S All points are obtained from the wear chord length point set. S c ; where, during the traversal of each point a At that time, find the midpoint of the contact line standard point cloud outline. a nearest point b and calculate the points a and points b Distance between d Determine distance d If it is greater than the threshold, then it represents a point. a On the worn chord length, the point a Add to the wear chord length point set S c middle; Preferably, step S41 includes:
[0028] in, Points in the cloud outline of the contact line a The coordinates; Points in the standard point cloud profile of the contact line b The coordinates; For point a and points b The distance between them; For the set of point cloud outlines of the contact line; This is the set of standard point cloud outlines of the contact line after it has been moved.
[0029] S42. Determine the set of points for determining wear chord length. S c If the number of midpoints exceeds a threshold, then the number of midpoints is determined based on the wear chord length point set. S c The wear chord length C is calculated from the left and right endpoints, and the distance between the wear chord length C and the lowest point of the contact line standard point cloud profile is taken as the wear height X. The wear area is calculated based on the left and right endpoints of the wear chord length C. s。
[0030] Preferably, in step S42, the wear area s for:
[0031] in, The area of wear; The radius of the standard point cloud profile of the contact line; The central angle corresponding to the wear chord length.
[0032] The beneficial effects of this invention are: 1. This invention employs a 3D structured light camera-based contact wire wear measurement method. This method can effectively replace traditional manual fixed-point detection for contact wire wear detection, and can continuously detect changes in contact wire wear. While ensuring measurement accuracy, it saves manpower and time costs, and effectively improves work efficiency.
[0033] 2. This invention uses profile extraction and profile matching to measure the wear of flexible contact wires, and can measure the wear of both standard and non-standard circular contact wires, making it highly versatile.
[0034] 3. This invention utilizes structured light measurement technology to provide high-precision three-dimensional data for high-precision wear measurement. Furthermore, it establishes a discrete profile of the standard contact wire and uses profile matching technology to make the measurement of wear on flexible contact wires more accurate. This method can continuously detect changes in conductor wear, rather than measuring only at specific points, which helps to comprehensively understand the condition of the conductor. It saves manpower and time, has a high degree of automation, and offers strong real-time performance on a vehicle-mounted basis. Attached Figure Description
[0035] Figure 1 This is a flowchart of the flexible contact wire wear measurement method of the present invention; Figure 2 This is a schematic diagram of the data acquisition system of the present invention; Figure 3 This is a panoramic view of the original point cloud and a magnified view of the contact line of the present invention; Figure 4 This is a schematic diagram of the standard contact line profile of the present invention; Figure 5 This is a schematic diagram of the original point cloud of the present invention; Figure 6 This is a schematic diagram showing the optimal center, radius, and orientation angle of the original point cloud of the present invention; Figure 7 This is a schematic diagram illustrating the moving matching of the acquired profile and the standard profile in this invention; Figure 8 This is a schematic diagram of the wear chord length point set of the present invention; Figure 9 This is a schematic diagram of the measurement results of the present invention. Detailed Implementation
[0036] 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 accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention.
[0037] A method for measuring contact wire wear in an intelligent overhead contact line inspection robot, such as Figure 1 As shown, this includes: raw point cloud input, profile extraction, profile matching, wear measurement, etc.
[0038] The specific steps of the method of the present invention are as follows: Step 1: Acquisition of raw point cloud data The input data of this invention is based on the raw data of the overhead contact line collected by an intelligent inspection robot for overhead contact lines that includes a 3D structured light imaging device. The schematic diagram of the acquisition system is shown below. Figure 2 As shown. The original panoramic cloud map is as follows. Figure 3 As shown, the contact line profile that this invention focuses on occupies only a small part of the field of view (dashed box in the figure), which includes other components of the contact wire and noise. The point cloud of the contact line needs to be extracted from the panoramic image later.
[0039] Step 2: Extraction of Flexible Contact Line Profile Based on the original point cloud panoramic image obtained in Step 1, the contact line profile is extracted. The purpose of this step is to remove interfering point clouds from the panoramic image and obtain the desired contact line point cloud profile. This invention employs a circular arc search method based on noise suppression, the specific process of which is as follows.
[0040] Set the required search radius range based on prior knowledge. r min , r max The setting depends on the specific conditions of the line, and is usually the standard radius of the contact wire in the operating line. r std Add or subtract 1.5mm.
[0041]
[0042] in, This represents the minimum search radius. This represents the maximum search radius. This refers to the standard radius of the contact wire in the operating circuit.
[0043] Three points were randomly selected from the original panoramic image. A ( x 1, y 1), B ( x 2, y2) and C ( x 3, y 3) Determine the center of the circle ( x c , y c ) and radius r ,in r belong( r min , r max ).
[0044]
[0045]
[0046]
[0047]
[0048]
[0049]
[0050] in, for AB The coordinates of the midpoint; for BC The coordinates of the midpoint; for AB The distance between them; for BC The distance between them; for AB The slope; for BC The slope; For AB Midpoint and AB The slope of a perpendicular line segment; For BC Midpoint and BC The slope of a vertical line segment.
[0051] Iterate through the remaining points and extract the point set. S 3, where the distance from a point to the center of the circle belongs to the interval (r- ,r+ )—— =0.5mm. Extract point set. S 4, where the distance from a point to the center of the circle belongs to the interval (0, r+). Noise suppression conditions, S The number of points in 3 is greater than the threshold n, and S 3 and S4. The sum of the number of elements in the intersection S The ratio of the number of elements in 4 is greater than p min —— p min =0.6. If S 3 and S 4. If the noise suppression condition is met, then the set will be... S In 3, the point represents an arc. S By fitting the midpoints of the three points, the center of the circle can be obtained. and radius .
[0052]
[0053]
[0054]
[0055]
[0056] Step 3: Shape Matching Step 3.1 Establishing the Standard Profile Because various contact wire specifications exist in my country's operating lines, the raw point cloud data collected is susceptible to noise and profile jitter. To improve measurement accuracy, this invention matches the collected contact wire profile with a standard contact wire profile, and performs wear measurements based on the matching results. First, a discrete template library is established according to the nominal specifications of the contact wire, such as... Figure 4 The figure shows the standard profiles of contact wires of different specifications.
[0057] Step 3.2 Matching the contact line point cloud profile with the standard profile The purpose of profile matching is to fit the collected point cloud onto a standard profile in preparation for wear measurement. The specific steps are as follows: (1) Input the original point cloud set S ,like Figure 5 As shown.
[0058] (2) Obtain the center and direction angle of movement of the original point cloud. The least squares method is used to process the input point cloud set. S By performing a fitting operation, the optimal center O can be obtained: And radius: R The formula is as follows:
[0059] in, n This indicates the number of points in the contact line point cloud profile; i Indicates the first i One point; Represents the coordinates of a point within the contact line point cloud outline; S This represents the outline of the contact line point cloud.
[0060] Half of the angle formed by the center O and the left and right endpoints A and B of the original point cloud is taken as the direction angle θ for the next step of moving the standard profile. Figure 6 As shown.
[0061] (3) Matching the standard profile and the acquired profile. The center O' of the standard profile is moved along the direction determined by θ, starting from the center O of the fitted circle; the movement stops when the average distance between the left and right arc regions of the original point cloud and the standard profile is less than 0.1 mm, such as... Figure 7 As shown.
[0062] Step 4: Wear Measurement In Step 3, the matching of the standard profile and the acquired profile is implemented, and wear measurement is performed based on the matching results. The point set of wear chord lengths is obtained by traversing all the original point clouds. The specific process is as follows: 1. Obtain the set of points containing the worn chord length. S c .
[0063] (1) such as Figure 8 As shown, traversal S All points in the original point set, when traversing to the original point set S In a When the point is a standard profile set, find the standard profile set. S std Mid-distance point a nearest point b .
[0064]
[0065] in, Points in the cloud outline of the contact line a The coordinates; Points in the standard point cloud profile of the contact line b The coordinates; For point a and points b The distance between them; For the set of point cloud outlines of the contact line; This is the set of standard point cloud outlines of the contact line after it has been moved.
[0066] (2) Obtained from (1) d The minimum value, if d >0.5mm, representing a On the worn chord length, then a Add to S c middle.
[0067] (3) Repeat (1) and (2) to guide the traversal to completion S All points in the middle.
[0068] 2. Calculate wear.
[0069] like Figure 9 As shown, obtain S c Later, when S c When the number of midpoints is greater than 5, according to S c The left and right endpoints can be used to calculate the chord length C of the wear. Based on the wear location, the wear height X is calculated from the lowest point of the standard profile along the chord. The wear area is calculated based on the left and right endpoints of the chord length. s .
[0070]
[0071] in, The area of wear; The radius of the standard point cloud profile of the contact line; The central angle corresponding to the wear chord length.
[0072] The embodiments of the present invention have been described in detail above, but 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 contact wire wear using an intelligent overhead contact line inspection robot, characterized in that, Includes the following steps: S1. Collect raw point cloud data of the flexible contact network; S2. The arc search method based on noise suppression is used to extract the contact line point cloud profile from the original point cloud data of the flexible contact wire. S3. Match the contact line point cloud profile with the corresponding standard contact line point cloud profile in the discrete template library; wherein, the discrete template library includes a variety of standard contact line point cloud profiles of different specifications, and the contact line includes standard circular contact lines and non-standard circular contact lines. S4. Measure the wear of the contact line by using the contact line point cloud profile after profile matching and the standard contact line point cloud profile.
2. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 1, characterized in that, Step S2 includes: S21. Set the required search radius range based on prior knowledge. r min , r max ), This represents the minimum search radius. This represents the maximum search radius. S22. Randomly select 3 points from the original point cloud data of the flexible contact network. A ( x 1, y 1), B ( x 2, y 2) and C ( x 3, y 3) Determine the center of the circle ( x c , y c ) and radius r , where the radius r belong( r min , r max ); S23. Traverse the remaining points in the original point cloud data of the flexible contact network and extract them to the center of the circle. x c , y c The distance of ) belongs to the interval (r- ,r+ The points form a point set. S 3. Extract the center of the circle ( x c , y c The distance of ) belongs to the interval (0, r+) The points form a point set. S 4; among which, Preset distance; S24, Determine the point set S 3 and point set S 4. Does the noise suppression condition meet? If so, then the point set... S In point 3, the point represents a segment of an arc and serves as the contact line point cloud outline. S .
3. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 2, characterized in that, In step S21, the minimum search radius is the standard radius of the contact wire minus 1.5 mm, and the maximum search radius is the standard radius of the contact wire plus 1.5 mm.
4. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 2, characterized in that, In step S24, the noise suppression condition includes: point set S The number of points in the 3-point system is greater than the threshold. n And point set S 3 and point set S 4. The number of elements in the intersection and the set of points S The ratio of the number of elements with a value of 4 is greater than the threshold. p min .
5. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 1, characterized in that, Step S3 includes: S31. Establish a discrete template library containing various standard point cloud profiles of contact wires based on the nominal specifications of the contact wire, and find the standard point cloud profile of the contact wire corresponding to the point cloud profile of the contact wire in the discrete template library. S32. The least squares method is used to fit the points in the contact line point cloud profile to obtain the center O of the fitted circle. and radius R ; S33. Take half of the angle formed by the center O and the left and right endpoints of the contact line point cloud profile as the direction angle of the moving contact line standard point cloud profile. S34. Move the center of the standard point cloud profile of the contact line along the direction angle, starting from the center of the fitted circle. Stop moving when the average distance between the left and right arc regions in the contact line point cloud profile and the standard point cloud profile of the contact line is less than the threshold.
6. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 5, characterized in that, Step S32 includes: in, n Indicates the number of points in the point cloud outline of the contact line; i Indicates the first i One point; Represents the coordinates of a point within the contact line point cloud outline; S This represents the outline of the contact line point cloud.
7. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 1, characterized in that, Step S4 includes: S41. Traverse the contact line point cloud outline S All points are obtained from the wear chord length point set. S c ; where, during the traversal of each point a At that time, find the midpoint of the contact line standard point cloud outline. a nearest point b and calculate the points a and points b Distance between d Determine distance d If it is greater than the threshold, then it represents a point. a On the worn chord length, the point a Add to the wear chord length point set S c middle; S42. Determine the set of points for determining wear chord length. S c If the number of midpoints exceeds a threshold, then the number of midpoints is determined based on the wear chord length point set. S c The wear chord length C is calculated from the left and right endpoints, and the distance between the wear chord length C and the lowest point of the contact line standard point cloud profile is taken as the wear height X. The wear area is calculated based on the left and right endpoints of the wear chord length C. s .
8. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 7, characterized in that, Step S41 includes: in, Points in the cloud outline of the contact line a The coordinates; Points in the standard point cloud profile of the contact line b The coordinates; For point a and points b The distance between them; For the set of point cloud outlines of the contact line; This is the set of standard point cloud outlines of the contact line after it has been moved.
9. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 7, characterized in that, In step S42, the wear area s for: in, The area of wear; The radius of the standard point cloud profile of the contact line; The central angle corresponding to the wear chord length.
10. The method for measuring contact wire wear of an intelligent overhead contact line inspection robot as described in claim 1, characterized in that, In step S1, a smart inspection robot for the overhead contact line, equipped with a 3D structured light imaging device, is used to collect raw point cloud data of the flexible overhead contact line.