CN-122015705-A - Hanging rail type contact line abrasion detection system and method

CN122015705ACN 122015705 ACN122015705 ACN 122015705ACN-122015705-A

Abstract

According to the rail-mounted contact line abrasion detection system and method, a reverse compensation mechanism is introduced to the technical bottleneck of measurement distortion caused by high-frequency nonlinear vibration in the prior art, and laser point cloud is reversely restored in an algorithm level, so that vehicle body vibration artifacts are effectively eliminated. Meanwhile, the problem that the traditional ICP easily falls into a local extremum when treating a flattened contact line with serious abrasion is solved, so that the repeatability error of abrasion detection is reduced to a sub-millimeter level, and the confidence level is ensured. And reversely guiding the two-dimensional image to generate a mask by utilizing the precisely registered geometric topological relation of the three-dimensional point cloud. The time consumption of reasoning is greatly reduced by more than 80%, the requirement of the embedded terminal (such as raspberry pie and Jetson Nano) with limited calculation force on high-frame-rate real-time detection is perfectly met, the unification of data is ensured, the integral detection precision is improved, the contact line abrasion state and the bolt loosening state can be truly reflected, and the method is suitable for industrial large-scale use and popularization.

Inventors

WANG LIANGLIANG
Meng Yiling
HE YUXIN
MEI HAO
XU SHEN
WANG XUEXIN
CHENG BIN
TIAN JINXING
SUN CHANGFEI
GUO KERAN
ZHOU JIANLU
YE HONGYU

Assignees

西安建筑科技大学

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (7)

1. The rail hanging type contact line abrasion detection system comprises a rail hanging type contact line abrasion detection device which is hung at the bottom of a bus bar, wherein a contact line extending along the length direction is arranged in the middle of the bottom end of the bus bar, and a plurality of pre-tightening bolts are arranged on two opposite side walls of the bus bar along the length direction; the rail-mounted contact line abrasion detection device comprises a moving mechanism and an obstacle avoidance mechanism, wherein the moving mechanism can drive the rail-mounted contact line abrasion detection device to move along a busbar, and the obstacle avoidance mechanism can drive the rail-mounted contact line abrasion detection device to avoid an obstacle on the busbar; the inertial measurement unit is arranged at the gravity center position of the hanging rail type contact line abrasion detection device and is used for detecting the acceleration and the angular velocity of the hanging rail type contact line abrasion detection device and transmitting the acceleration and the angular velocity to the controller; the absolute value encoder is arranged on the moving mechanism and used for detecting the travelling distance of the moving mechanism and transmitting the travelling distance to the controller; The area array camera is arranged on the side wall of the rail-mounted contact line abrasion detection device and is used for shooting two-dimensional images of the two side walls of the bus and transmitting the two-dimensional images to the controller, wherein the two-dimensional images are specifically two-dimensional pixel images containing pre-tightening bolts of the two side walls of the bus; The line laser profiler is arranged below the area array camera, and an outgoing line beam of the line laser profiler crosses the section of the contact line and forms an included angle with the optical axis of the area array camera; the three-dimensional lattice image comprises a contact line shape curve image and two side lattice images at the bottom of the bus; The contact line shape curve image specifically comprises a curve which is composed of a plurality of points and reflects the shape of the cross section edge of the contact line bottom, and the lattice image on the two sides of the bus bottom specifically comprises a lattice image which is composed of a plurality of points and reflects the shape of the bottom end of the two side walls of the bus bottom; The controller set up in hanging rail formula contact line wearing and tearing detection device inside, the controller is used for: Controlling the moving mechanism to move along the bus bar; Controlling an obstacle avoidance mechanism to avoid an obstacle; setting sampling step sizes of a line laser profiler, an area array camera and an inertial measurement unit; Synchronously sampling the line laser profiler and the area array camera according to a fixed step length; performing image correction on the contact line shape curve image to obtain a standard contact line shape curve image; And performing image processing on the standard contact line shape curve image, the lattice images on two sides of the bottom of the busbar and the two-dimensional image, so as to obtain the abrasion condition of each position of the contact line and the loosening condition of the pre-tightening bolt.
2. A contact wire wear detection method based on the rail mounted contact wire wear detection system of claim 1, comprising the steps of: step 1, setting sampling step sizes of a line laser profiler and an area array camera; Step 2, enabling the moving mechanism to move at a constant speed along the bus, and enabling the line laser profiler and the area array camera to sample simultaneously when the moving distance reaches the sampling step length set in the step 1; the position in the sampling is recorded as the current position; Step 3, carrying out image correction on the contact line shape curve image, taking the corrected three-dimensional lattice image as a standard contact line shape curve image, and entering step 4; step 4, setting a surface curvature judgment threshold value of the contact line; Judging whether abrasion of the contact line occurs at the current position or not according to the surface curvature of the curve in the standard contact line shape curve image and the relationship between the surface curvature and the surface curvature judgment threshold value; step5, respectively projecting central lines of bottoms of two sides of the bus in the dot matrix images of two sides of the bottom of the bus into corresponding two-dimensional images to serve as two-dimensional datum lines; taking the two-dimensional datum line as a reference, and circling an area where the pre-tightening bolt is positioned in the two-dimensional image as a target area; performing dimension reduction and noise resistance treatment on a target area to obtain a target image only containing the pre-tightening bolts, and identifying loosening conditions of the pre-tightening bolts in the target image; and 6, repeating the steps 2-5 until the rail-mounted contact line abrasion detection device reaches the bus bar end point, and acquiring the abrasion condition of the contact line at each sampling position of the bus bar and the loosening condition of the pre-tightening bolt.
3. The contact line wear detection method of the rail mounted contact line wear detection system according to claim 2, wherein in step 1, the sampling step size is 5-15mm.
4. The contact line wear detection method of a rail mounted contact line wear detection system of claim 2, wherein step 3 specifically comprises the sub-steps of: Step 31, calculating the roll angle and pitch angle of the rail-mounted contact line abrasion detection device according to the current position of the rail-mounted contact line abrasion detection device during current sampling, the speed during current sampling, the acceleration and the angular speed during current sampling by using an error state extended Kalman filtering algorithm; Step 32, constructing a reverse kinematics compensation matrix of each point in the contact line shape curve image according to the roll angle and the pitch angle obtained by calculation in the step 31; step 33, for any point in the three-dimensional lattice image, performing inverse transformation by using an inverse kinematics compensation matrix corresponding to the point to obtain a corrected point; and traversing each point in the three-dimensional lattice image by using the method, acquiring a corrected contact line shape curve image, and taking the corrected contact line shape curve image as a standard contact line shape curve image.
5. The contact line wear detection method of a rail mounted contact line wear detection system of claim 4, wherein step 4 specifically comprises the sub-steps of: Step 41, setting a surface curvature determination threshold value, as follows: Wherein, the Representing a surface curvature determination threshold; a mathematically expected mean value representing the standard CAD section surface curvature of the contact line; Representing the tolerance sensitivity adjustment coefficient, ; Standard deviation of the surface curvature of a standard CAD section representing the contact line; step 42, selecting one end point of the curve for the standard contact line shape curve image, and constructing the point neighborhood point set selected this time A covariance matrix; For said The covariance matrix performs eigenvalue decomposition to obtain three eigenvalues arranged in order from small to large ; And 43, calculating the surface curvature corresponding to the point selected at this time by taking the ratio of the minimum characteristic value to the sum of the three characteristic values, wherein the surface curvature is represented by the following formula: Wherein, the Representing the surface curvature corresponding to the point selected at this time; Step 44, if the surface curvature of the selected point Surface curvature determination threshold value Then the point selected this time wears out and the point is designated as the wear point, and the process proceeds to step 46; if the surface curvature of the selected point is the same Surface curvature determination threshold value Step 45, if the corresponding position of the point selected at the present time is not worn; Step 45, selecting a point adjacent to the point selected in step 45 in the standard contact line shape curve image again, and repeating steps 43-44 until all points in the standard contact line shape curve image are traversed or abrasion points are obtained; if all points in the standard contact line shape curve image are traversed and no abrasion points exist, the contact line at the current position is free from abrasion; If the wear point is obtained, all the surface curvatures Surface curvature determination threshold value Is defined as an unworn point, step 46 is entered; step 46, for the standard contact line shape curve image, selecting the point of the other end point of the curve, repeating steps 42-45 until another abrasion point is obtained; step 47, respectively selecting unworn points adjacent to the two wear points as two hanging points; Step 48, correcting all unworn points and hanging points by using an ICP accurate matching algorithm according to the standard CAD section of the contact line; Connecting two corrected hanging ring points, obtaining real coordinates of the two corrected hanging ring points, connecting the two hanging ring points, taking a straight line formed by connecting the two corrected hanging ring points as a wearing line at the current position of a contact line, and taking a region formed by the wearing line and the bottom of a standard CAD section as a wearing region at the current position of the contact line.
6. The contact line wear detection method of a rail mounted contact line wear detection system of claim 5, wherein step 5 specifically comprises the sub-steps of: Step 51, extracting a central line of one side of the bus bottom from the lattice image of the one side as a space three-dimensional geometric datum line; step 52, projecting the space three-dimensional geometric datum line onto a two-dimensional image of the corresponding side wall of the busbar to form a two-dimensional datum line; step 53, translating towards the direction of the pre-tightening bolt in the two-dimensional image by taking the two-dimensional datum line as a reference until translating to the bottom of the pre-tightening bolt, and circling the area where the pre-tightening bolt is positioned as a target area; step 54, identifying pre-tightening bolts in a target area by using a dynamic mask generation algorithm according to a standard design drawing of the busbar; Step 55, outputting the loosening state of the pre-tightening bolt by using YOLOv-tiny target detection network; And 56, extracting the center line of the side from the dot matrix image of the other side of the bottom of the bus bar, taking the center line as a space three-dimensional geometric datum line, and repeating the steps 52-55 to obtain the loosening state of the pre-tightening bolts of the two side walls of the bus bar.
7. The method for detecting contact line abrasion of the on-orbit contact line abrasion detecting system according to claim 6, wherein when the step 52 projects the spatial three-dimensional geometric reference line onto the two-dimensional image of the corresponding side wall of the busbar, specifically, each point of the spatial three-dimensional geometric reference line is projected onto the two-dimensional image of the corresponding side wall of the busbar to form a reference point corresponding to each point of the spatial three-dimensional geometric reference line one by one, and further, the two-dimensional reference line is formed by a plurality of reference points; The projection transformation formula of any point in the space three-dimensional geometric datum line is as follows: Wherein X, Y, Z respectively represent three-dimensional coordinate components of any one point on the spatial three-dimensional geometric reference line; u and v respectively represent coordinates corresponding to points projected onto the two-dimensional image by points on the spatial three-dimensional geometric reference line; Representing depth values of points projected onto the two-dimensional image under an area array camera coordinate system; K represents an internal reference matrix of the area array camera; and the joint external parameter matrix from the coordinate system of the linear laser profiler to the coordinate system of the area array camera is represented.

Description

Hanging rail type contact line abrasion detection system and method Technical Field The invention belongs to the technical field of intelligent operation and maintenance of rail transit and machine vision detection, and particularly relates to a rail hanging type contact line abrasion detection system and method. Background The busbar sets up in the tunnel is inside, and the busbar lower part is provided with the contact line along length direction, and this kind of system is the key equipment that the train safety and stability got the stream. The contact line is used as a part directly rubbed with the pantograph, and the abrasion condition of the contact line is directly related to the power supply reliability and the operation safety. If the abrasion exceeds the safety limit and is not replaced in time, serious accidents such as broken lines, arc discharge and the like can be caused, and the operation of the subway is interrupted. In the prior art, there is a device capable of being mounted on a busbar to move and avoid an obstacle, for example, a clamping walking device of a rail-mounted contact line abrasion detection robot is given in chinese patent CN 121105936B. However, in the extreme environment where the space of the subway tunnel is limited, the multi-source noise is coupled and there is no external navigation signal (GPS rejection), when automatic detection of the contact wires based on such a device is required, the existing detection technology exposes the following significant drawbacks: first, the detection dynamic measurement accuracy is low. In the prior art, a line laser profiler is adopted to collect a three-dimensional lattice image, and the existing method is highly dependent on the stability of a detection platform, but the bus is rigid and is in a zigzag trend, and the rigidity mutation exists at the joint of the bus, so that distortion is generated when a detection device is over the obstacle, the vibration of the vehicle body is misjudged as the profile change of a contact line, and a great false abrasion error is introduced. Secondly, in the prior art, a YOLOv-tiny target detection network is usually adopted to output the loosening state of a bolt, the YOLOv-tiny target detection network is a well-known target detection network with an open source, but because the illumination in a subway tunnel is uneven, dust and oil are densely distributed, and strong anti-light spots exist on the surface of an aluminum alloy busbar, the anti-light spots exist on the surface of the aluminum alloy busbar Some background noise is highly susceptible to errors by the algorithm as a bolt or to causing missed detection. Meanwhile, the background area of the contact net detection accounts for more than 80% in the whole image, the convolution operation on the whole image leads to extremely high calculation redundancy, and real-time processing with high frame rate is difficult to realize on embedded edge equipment (such as raspberry pie, jetson and the like) with limited calculation power. Thirdly, in the prior art, space-time fracture exists during detection, the contact line abrasion (3D geometric quantity) and the fastener state (2D texture quantity) serve as two completely independent isolated tasks, and various sensors (a laser, a camera and an inertial navigation module) respectively acquire data asynchronously according to different frequencies. This "self-contained" architecture results in multi-modal data that is not precisely aligned in "time stamps" and "mileage coordinates". In summary, the detection accuracy of the detection method in the prior art is insufficient, and the contact line abrasion state and the bolt loosening state cannot be truly reflected. Disclosure of Invention The invention aims to provide a rail hanging type contact line abrasion detection system and method, which are used for solving the problems that the detection accuracy of the detection method in the prior art is insufficient and the contact line abrasion state and the bolt loosening state cannot be truly reflected. In order to solve the technical problems, the invention adopts the following technical scheme: The rail hanging type contact line abrasion detection system comprises a rail hanging type contact line abrasion detection device which is hung at the bottom of a bus bar, wherein a contact line extending along the length direction is arranged in the middle of the bottom end of the bus bar, and a plurality of pre-tightening bolts are arranged on two opposite side walls of the bus bar along the length direction; the rail-mounted contact line abrasion detection device comprises a moving mechanism and an obstacle avoidance mechanism, wherein the moving mechanism can drive the rail-mounted contact line abrasion detection device to move along a bus bar, and the obstacle avoidance mechanism can drive the rail-mounted contact line abrasion detection device to avoid an obstacle on the bus bar; the inertial measurement