Contact suspension positioning acquisition method and system

Abstract

The invention discloses a contact suspension positioning acquisition method and system, and belongs to the technical field of catenary detection.The method comprises the steps that an image of a catenary is acquired in real time through a contact suspension high-speed acquisition unit, the image of the catenary is recognized, and when it is recognized that a contact suspension wire clamp exists, the contact suspension wire clamp is detected; and determining the triggering time for triggering the contact suspension shooting unit to obtain the contact suspension image, and controlling the contact suspension shooting unit to shoot the contact suspension and store the shooting result when the triggering time is reached. According to the method provided by the invention, after the contact suspension is determined to be identified, another image acquisition device is used for acquiring and storing the image, so that the problem of redundancy of the acquired image caused by storing all the images is avoided. And the contact suspension area is determined by identifying the contact suspension wire clamp, so that the problems of missed shooting and the like caused by the fact that abnormal contact suspension (disconnection, breakage and loss states) cannot be accurately identified in a direct contact suspension identification mode are solved.

Description

Technical Field

[0001] This invention relates to the field of overhead contact line inspection technology, specifically to a contact suspension positioning and acquisition method and system. Background Technology

[0002] The railway overhead contact system is an important component of electrified railways, and its contact suspension directly affects the safety and stability of train operation. Therefore, it is necessary to conduct corresponding inspections on the contact suspension.

[0003] Traditional detection methods involve continuous image acquisition, which captures images of designated locations on the overhead contact line at a preset acquisition frequency. However, due to varying vehicle operating conditions, some acquired images may not be of the required contact suspension location, while images of the required contact suspension location may not be captured. This results in inaccurate positioning of the contact suspension images, leading to image redundancy and omissions. To avoid inaccurate positioning, existing technologies also employ contact suspension positioning and imaging methods, which acquire images only after identifying the contact suspension. However, this identification is based on the location of the suspension, so when abnormal contact suspension conditions exist (detachment, breakage, or loss), the location of the contact suspension cannot be accurately identified because it cannot be detected, resulting in missed images.

[0004] Therefore, existing technologies have problems such as large amounts of redundant data due to inaccurate positioning of the contact suspension in continuous shooting methods, display of contact suspension components in single image shooting, and missed shots caused by the inability to identify abnormal contact suspension feature images in contact suspension positioning shooting methods. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a contact suspension positioning and acquisition method and system to solve the problems of large amount of redundant data caused by inaccurate contact suspension positioning, display of contact suspension components in single image capture, and missed capture caused by the inability to identify abnormal contact suspension feature images in the contact suspension positioning and acquisition method.

[0006] To achieve the above objectives, this invention discloses a contact suspension positioning and data acquisition method. Specifically, the method includes the following steps:

[0007] When the overhead contact line inspection train is not running, the actual distance between the high-speed acquisition unit of the contact suspension at the front and the shooting unit of the contact suspension at the rear, which are set on the roof of the overhead contact line inspection train, in the direction of travel is obtained in advance. This actual distance is taken as the distance between the center of vision of the high-speed acquisition unit of the contact suspension and the shooting unit of the contact suspension in the direction of travel.

[0008] During the operation of the overhead contact line inspection train, the train speed is acquired in real time, and images of the overhead contact line are acquired in real time through the high-speed acquisition unit of the contact suspension. The images of the overhead contact line are then identified. When a contact suspension clamp is identified, the corresponding image of the overhead contact line is identified in the contact suspension area, and the trigger time for the contact suspension imaging unit to acquire the contact suspension image is determined.

[0009] The determination of the trigger time includes: determining the distance between the center point of the contact suspension clamp and the center point of the image in the direction of travel, converting the distance into an actual distance, and obtaining the trigger time by adding the actual distance to the distance of the center of the field of view in the direction of travel and dividing the sum by the speed of the contact wire detection train.

[0010] When the trigger time is reached, the contact suspension imaging unit is triggered to control the contact suspension imaging unit to take pictures of the contact suspension and store the picture results.

[0011] The beneficial effects are as follows: The method of the present invention avoids the problem of image redundancy caused by storing all images by using another image acquisition device to acquire and store images after identifying the contact suspension. In this invention, the contact suspension area is determined by identifying the contact suspension clamp, avoiding the problem of missed images caused by the inaccurate identification of abnormal contact suspension (detached, broken, or lost state) in the direct identification of contact suspension. Furthermore, when determining the trigger time for the contact suspension imaging unit to acquire contact suspension images, only images containing contact suspension clamps are further processed and signal triggered, and images of invalid areas are directly filtered out. This target-oriented processing method greatly reduces the generation of useless data. Moreover, by considering the distance of the already identified contact suspension clamp from the imaging center and using the confirmation method of the present invention, the contact suspension imaging unit not only avoids missing contact suspension images but also ensures that the acquired contact suspension images are as close as possible to the center of the imaging position, thereby avoiding the situation where contact suspension images are acquired but not completely acquired. Therefore, the method of the present invention solves the problems of large amount of redundant data caused by inaccurate positioning of contact suspension, display of contact suspension components in single image shooting, and missed shooting caused by the inability to identify abnormal contact suspension feature images in the contact suspension positioning and shooting method.

[0012] Furthermore, it also includes: before the overhead contact line inspection train is in operation, obtaining the minimum value of the distance between adjacent contact suspensions on the line where the overhead contact line inspection train is running; when the overhead contact line inspection train is in operation, determining the minimum triggering time interval for triggering the contact suspension imaging unit to acquire contact suspension images based on the ratio of the minimum value to the speed of the overhead contact line inspection train; after triggering the contact suspension imaging unit when the triggering time is reached, blocking the operation of triggering the contact suspension imaging unit within the minimum triggering time interval.

[0013] The method of this invention also incorporates basic information on high-speed and conventional railways, including a limit on the distance between adjacent contact suspensions. Therefore, before the catenary inspection train runs (i.e., before the acquisition of contact suspension images begins), this limit (i.e., the minimum distance between adjacent contact suspensions on the catenary inspection train's running line, where the distance is in the direction of travel) is first obtained. This limit, along with the real-time speed of the inspection train, is used to determine the minimum time required for one contact suspension to reach its adjacent contact suspension. Since no contact suspension image exists within this time interval, this time value is used as the minimum triggering time interval in this invention. Triggering signals within this time range are shielded, and invalid triggering signals are removed, thus avoiding the acquisition of redundant images within this time range, and further avoiding image redundancy. Furthermore, this invention takes into account that in the image acquisition of the high-speed acquisition unit for the contact suspension clamp, multiple consecutive images may be acquired for the same contact suspension clamp. In addition, this invention takes measures to ensure that the contact suspension clamp can be close to the center of the imaging position. Therefore, the trigger signals obtained for the contact suspension clamp in subsequent consecutive images are all multiple trigger signals. Thus, the method based on the minimum trigger time interval of this invention avoids the redundant images triggered by the trigger signal, ensuring that the contact suspension is in the middle position of the image in the captured image.

[0014] Furthermore, triggering the contact suspension imaging unit when the trigger time is reached includes: generating an analog signal to trigger the contact suspension imaging unit to capture images when the trigger time is reached, amplifying the analog signal, and sending the amplified analog signal to the contact suspension imaging unit.

[0015] Within the minimum trigger time interval, shielding the operation that triggers the contact suspension imaging unit includes: shielding the generated analog signal that triggers the contact suspension imaging unit to capture images within the minimum trigger time interval.

[0016] In this invention, after determining the trigger time, the signal is transmitted to the contact suspension imaging unit only when the trigger time is reached. Furthermore, the shielding operation is performed before transmission, that is, the minimum trigger time interval is used as the shortest time interval for sending the trigger signal, and the analog signal generated within the shortest time interval is shielded to remove invalid trigger signals and ensure that the contact suspension is in the center of the captured image.

[0017] Furthermore, the formula for calculating the trigger time is: T=[L+M(X1-X2)] / V, where T is the trigger time, L is the distance between the center of vision of the contact suspension high-speed acquisition unit and the contact suspension shooting unit in the direction of travel, M is the actual distance represented by a single pixel in the image in the direction of travel, X1 is the coordinate of the center point of the contact suspension clamp in the direction of travel in the image, X2 is the coordinate of the center point of the image in the direction of travel in the image, and V is the speed of the contact wire detection train.

[0018] This invention uses the driving direction as a reference to determine the distance L between the centers of the fields of view of the two modules, the high-speed acquisition unit and the shooting unit, in the driving direction. When the high-speed acquisition unit detects the contact suspension clamp, it calculates the coordinate position X1 of the center point of the contact suspension clamp in the driving direction of the image, the coordinate position X2 of the center point of the image in the driving direction of the image, and the actual distance M represented by a single pixel in the image in the driving direction of the image. Therefore, based on the calculation of M(X1-X2) in this invention, the actual distance between the center point of the contact suspension clamp and the center point of the image in the driving direction of the image is obtained. The sum of this actual distance and L is the actual distance from the contact suspension clamp to the center of the field of view of the shooting unit. Then, based on the obtained vehicle speed V, the optimal trigger time for imaging the contact suspension at the center of the field of view of the shooting unit is obtained.

[0019] Furthermore, the image recognition of the contact network includes: filtering and enhancing the image of the contact network to eliminate interference data in the image and improve the image clarity and contrast; and using the YOLOv5 model to perform target detection of the contact suspension clamp on the filtered and enhanced image.

[0020] Image recognition technology is becoming increasingly mature in the field of catenary inspection, and the level of automation and intelligence of image algorithms is improving. Therefore, this invention adopts image recognition technology and can achieve accurate positioning of catenary suspension clamps in all states by identifying them. In the image recognition process, filtering and image enhancement are performed first to eliminate interference data in the image and improve the image clarity and contrast, thereby improving the accuracy of subsequent recognition results. Furthermore, the YOLOv5 model is used to perform target detection on the catenary suspension clamps. This model has high robustness to catenary suspensions in all states (normal, detached, broken, lost), and can accurately locate the clamps even in complex backgrounds or abnormal conditions, solving the problem of missed identification caused by the looseness, detachment, or breakage of catenary suspensions when traditional direct identification of catenary suspensions is used.

[0021] To achieve the above objectives, the present invention also discloses a contact suspension positioning and acquisition system, which achieves the same beneficial effects as the above method. Specifically, the system includes: a contact suspension high-speed acquisition unit, a contact suspension imaging unit, an image processing unit, and a signal processing unit. With the driving direction as the forward direction, the contact suspension high-speed acquisition unit is arranged in front of the contact suspension imaging unit. The acquisition surfaces of both the contact suspension high-speed acquisition unit and the contact suspension imaging unit are perpendicular to the driving direction, and the acquisition surfaces are oriented towards the direction where the contact wire is located.

[0022] The high-speed acquisition unit for the contact suspension is used to acquire images of the contact network in real time during the operation of the contact network inspection train, and transmit the images to the image processing unit;

[0023] When the overhead contact line inspection train is not running, the image processing unit stores the actual distance between the high-speed acquisition unit and the shooting unit in the direction of travel as the distance between the center of view of the high-speed acquisition unit and the shooting unit in the direction of travel. When the overhead contact line inspection train is running, the image processing unit receives an image of the overhead contact line and identifies the image. When a contact suspension clamp is identified, the corresponding image of the overhead contact line is identified as being in the contact suspension area, and a trigger time is determined to trigger the shooting unit to acquire the contact suspension image. When the trigger time is reached, a trigger signal is transmitted to the signal processing unit. The determination of the trigger time includes: determining the distance between the center point of the contact suspension clamp in the direction of travel and the center point of the image in the image, converting this distance into an actual distance, and obtaining the trigger time by adding the actual distance to the distance of the center of view in the direction of travel and dividing the sum by the speed of the overhead contact line inspection train at this time.

[0024] The signal processing unit is used to process the trigger signal and then transmit it to the contact suspension shooting unit;

[0025] The contact suspension imaging unit is used to take pictures of the contact suspension and store the pictures when a trigger signal is received.

[0026] Furthermore, when the overhead contact line inspection train is not running, the image processing unit also stores the minimum value of the distance between adjacent contact suspensions on the track where the overhead contact line inspection train is running; when the overhead contact line inspection train is running, the image processing unit determines the minimum trigger time interval for triggering the contact suspension imaging unit to acquire contact suspension images based on the ratio of the minimum value to the speed of the overhead contact line inspection train, and after triggering the contact suspension imaging unit when the trigger time is reached, the operation of triggering the contact suspension imaging unit is blocked within the minimum trigger time interval.

[0027] Furthermore, the trigger signal is an analog signal, and processing the trigger signal includes amplifying the analog signal;

[0028] Within the minimum trigger time interval, shielding the operation that triggers the contact suspension imaging unit includes: shielding the generated analog signal that triggers the contact suspension imaging unit to capture images within the minimum trigger time interval.

[0029] Furthermore, the formula for calculating the trigger time is: T=[L+M(X1-X2)] / V, where T is the trigger time, L is the distance between the center of vision of the contact suspension high-speed acquisition unit and the contact suspension shooting unit in the direction of travel, M is the actual distance represented by a single pixel in the image in the direction of travel, X1 is the coordinate of the center point of the contact suspension clamp in the direction of travel in the image, X2 is the coordinate of the center point of the image in the direction of travel in the image, and V is the speed of the contact wire detection train.

[0030] Furthermore, the image recognition of the contact network includes: filtering and enhancing the image of the contact network to eliminate interference data in the image and improve the image clarity and contrast; and using the YOLOv5 model to perform target detection of the contact suspension clamp on the filtered and enhanced image.

[0031] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is a flowchart of the contact suspension positioning and data acquisition method in this embodiment;

[0033] Figure 2This is a layout diagram of the contact suspension positioning and acquisition system used in this embodiment on the roof of the contact wire inspection train;

[0034] Figure 3 This is a schematic diagram of the contact suspension high-speed acquisition unit structure used in the system of this embodiment;

[0035] Figure 4 This is a flowchart of the contact suspension positioning and acquisition system in this embodiment;

[0036] Figure 5 This is a schematic diagram of the implementation scheme of the contact suspension positioning and acquisition method in this embodiment.

[0037] In the diagram: 1-Contact suspension high-speed acquisition unit; 2-Contact suspension imaging unit; 3-High-speed camera; 4-Modulation light source; 5-Outer frame of rotating bracket; 6-Inner frame of rotating bracket; 7-Contact line; 8-Contact suspension. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art should understand that the embodiments described below are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Example of a contact suspension positioning and acquisition system

[0040] To avoid the problems of large amounts of redundant data, display issues in single-image capture of contact suspension components, and missed images caused by the inability to identify abnormal contact suspension features in existing contact suspension positioning and capturing methods, this embodiment of the system addresses these issues by setting up a high-speed contact suspension acquisition unit that continuously captures and stores images of the contact suspension components. This solves the image redundancy problem caused by capturing images of the contact wire mesh from all directions. Furthermore, the image processing unit in this embodiment acquires and identifies the images captured by the high-speed contact suspension acquisition unit in real time, based on the identification of the contact suspension clamps. This avoids missed images caused by the inability to identify contact suspension components in abnormal situations. In addition, the image processing unit in this embodiment also considers the position of the contact suspension clamps relative to the imaging center, so that the image is only taken and stored when the contact suspension clamps reach the imaging center of the contact suspension capturing unit, thus avoiding incomplete contact suspension imaging.

[0041] like Figure 2 As shown, the system in this embodiment includes a contact suspension high-speed acquisition unit 1, a contact suspension imaging unit 2, an image processing unit, and a signal processing unit. For example... Figure 3As shown, the arrow at the bottom indicates the direction of travel. With the direction of travel as the forward direction, the high-speed acquisition unit of the contact suspension is set in front of the contact suspension imaging unit. Therefore, during the train operation, the high-speed acquisition unit of the contact suspension always reaches a specific position before the contact suspension imaging unit. The acquisition surfaces of both the high-speed acquisition unit of the contact suspension and the contact suspension imaging unit are perpendicular to the direction of travel, and the acquisition surfaces are oriented towards the direction of the contact wire. Figure 3 The diagram illustrates the position of contact line 7. Therefore, the direction of the acquisition surface is perpendicular to the direction of travel, defining the plane in which the acquisition surface faces. Then, the specific angle of the acquisition surface towards the contact wire defines the angle, enabling the acquisition of images of the contact wire. Furthermore, the contact suspension imaging units are arranged on both sides of the contact line, allowing for comprehensive acquisition of images from both the front and back of the contact suspension. Figure 4 As shown, the contact suspension high-speed acquisition unit 1 in this embodiment includes a high-speed camera 3 and a modulation light source 4 disposed next to the high-speed camera 3. The modulation light source is set for supplementary lighting, so the emission direction of the modulation light source is the same as the direction of the acquisition surface of the high-speed camera. That is, a high frame rate camera is used in conjunction with the modulation light source for supplementary lighting to acquire images of the contact network and obtain clearer image data. In addition, the contact suspension high-speed acquisition unit 1 in this embodiment is also equipped with an angle-adjustable bracket. The upward shooting angle of the acquisition unit can be adjusted according to different line guide heights, and it is compatible with various line guide heights. The angle-adjustable bracket in this embodiment is a rotating bracket, which includes an outer frame 5 and an inner frame 6 disposed within the outer frame 5. Multiple mounting holes are provided on both the outer frame 5 and the inner frame 6. Bolts are passed through the corresponding mounting holes of the outer frame 5 and the inner frame 6 and nuts are used for fixing, thereby fixing the outer frame 5 and the inner frame 6. The mounting angle of the inner and outer frames can be adjusted by fixing them to different mounting holes, thereby adjusting the direction of the acquisition surface of the high-speed camera.

[0042] The high-speed acquisition unit for the contact suspension in this embodiment is used to acquire images of the contact network in real time during the operation of the contact network inspection train, and transmit the images to the image processing unit;

[0043] When the overhead contact line inspection train is not running, the image processing unit stores the actual distance between the high-speed acquisition unit and the imaging unit in the direction of travel as the distance between the center of view of the high-speed acquisition unit and the imaging unit in the direction of travel. When the overhead contact line inspection train is running, the image processing unit receives an image of the overhead contact line and uses it to identify the image of the overhead contact line. When a contact suspension clamp is identified, the corresponding image of the overhead contact line is identified in the contact suspension area, and the trigger time for triggering the imaging unit to acquire the image of the contact suspension is determined. When the trigger time is reached, the trigger signal is transmitted to the signal processing unit.

[0044] The signal processing unit processes the trigger signal and then transmits it to the contact suspension shooting unit;

[0045] The contact suspension imaging unit is used to take pictures of the contact suspension and store the pictures when a trigger signal is received.

[0046] The following is a detailed description of each module of the system in this embodiment:

[0047] 1. High-speed acquisition unit: Employs a high frame rate camera with modulated light source for illumination to acquire images of the overhead contact line suspension clamps. Each acquired image is 100,000 pixels in size and is used for target recognition.

[0048] Image Acquisition: After the device is started, the high-speed acquisition unit enters standby mode and receives speed information provided by other modules in real time. Based on the vehicle speed and the geometric relationship between the camera and the contact line, the acquisition frame rate is calculated in real time. The calculated frame rate is then used to trigger the high-speed camera to perform full-coverage image acquisition in real time.

[0049] Geometric correction: Using the camera's flat field correction function, distortion correction is performed on the acquired images to ensure the accuracy of the position and size of the clamp components in the acquired images under different angles and object distances.

[0050] 2. Image recognition and processing unit: Performs noise reduction and enhancement processing on the images captured by the high-speed acquisition unit, accurately identifies the position of the positioning clamp, and sets an effective trigger signal to the imaging unit by combining the vehicle travel distance calculated from the vehicle speed and the spacing between the overhead contact line suspensions.

[0051] Image enhancement: Gaussian filtering is used to remove image noise and eliminate interfering data (spots, reflections, etc.) to reduce ambient light and vibration interference. Simultaneously, histogram equalization is used to enhance the image, improving clarity and contrast under different lighting conditions or complex backgrounds.

[0052] Target Detection: Considering the requirements of detection scenario, detection speed, and detection accuracy, the YOLOv5 model is used for target detection of contact suspension clamps. A pre-trained model is used, combined with a contact clamp feature dataset for transfer learning, to improve detection accuracy.

[0053] Signal transmission: Calculate the vehicle travel distance based on the vehicle speed, and calculate the shortest time interval for triggering signal transmission by combining the distance between the contact suspensions and the geometric positional relationship between the high-speed acquisition unit and the shooting unit. Remove invalid trigger signals to ensure that the contact suspension is in the center of the image captured by the shooting unit.

[0054] Figure 5 The diagonal line in the middle shows a schematic diagram of the contact suspension. Figure 2 The image also shows the positional relationship between the contact suspension 8 and the system in this embodiment. The specific process of generating the trigger signal in this embodiment is as follows: 1) Both the high-speed acquisition unit and the shooting unit are installed on the roof of the detection vehicle, and the shooting direction is perpendicular to the driving direction. Taking the driving direction as the reference, the high-speed acquisition unit is installed in front of the shooting unit. The distance between the center of the field of view of the two modules in the driving direction is L meters (a fixed value after installation), and the distance between the two modules and the center of the rail is equal; 2) After the image captured by the high-speed acquisition unit detects the contact suspension clamp, the center point of the clamp in the driving direction in the image is calculated using the target recognition algorithm with the upper left corner of the image as the origin (0,0). The coordinates (X1, Y1) on the image, the coordinates (X2, Y2) of the center point of the image, and the actual distance M represented by a single pixel in the direction of travel in the image, combined with the obtained vehicle speed V, are used to calculate the optimal trigger time as: T=[L+M(X1-X2)] / V; 3) The shooting unit is controlled to take pictures of the contact suspension according to the calculated optimal trigger time; 4) Based on the basic information of high-speed railway and conventional railway, the distance between adjacent contact suspensions is greater than N meters. The minimum trigger time interval is calculated according to the vehicle speed as: T1=N / V. The trigger signals within the time range of (T, T+T1) are shielded to remove invalid trigger signals.

[0055] 3. Signal processing unit: Receives analog signals from the image recognition processing unit, amplifies the analog signals, and transmits them to the imaging unit.

[0056] 4. Imaging Unit: Upon receiving a trigger signal, two 25-megapixel high-definition cameras are activated to capture high-definition images of the front and back of the contact suspension at a fixed point. The captured high-definition images can be used for subsequent defect identification or manual inspection.

[0057] The workflow of this embodiment is as follows: the high-speed acquisition unit acquires images → the image recognition and processing unit processes the images → the image recognition and processing unit sends out analog signals → the signal processing unit forwards the analog signals → the imaging unit receives the signals → the imaging unit acquires and stores images of the front and back sides of the contact suspension. Figure 1 As shown, the specific methods and steps include the following:

[0058] When the overhead contact line inspection train is not running, the actual distance between the high-speed acquisition unit of the contact suspension set at the front and the shooting unit of the contact suspension set at the rear on the roof of the overhead contact line inspection train in the direction of travel is obtained in advance. This actual distance is used as the distance between the center of vision of the high-speed acquisition unit of the contact suspension and the shooting unit of the contact suspension in the direction of travel, and the minimum value of the distance between adjacent contact suspensions on the running line of the overhead contact line inspection train is obtained.

[0059] During the operation of the overhead contact line inspection train, the train speed is acquired in real time. Images of the overhead contact line are acquired in real time through the high-speed acquisition unit of the contact suspension. The images are filtered and enhanced. The YOLOv5 model is used to detect contact suspension clamps in the filtered and enhanced images. When a contact suspension clamp is detected, the distance between the center point of the contact suspension clamp and the center point of the image in the direction of travel is determined and converted into an actual distance. The actual distance is added to the distance of the center of the field of view in the direction of travel and divided by the speed of the overhead contact line inspection train to determine the trigger time for the contact suspension imaging unit to acquire contact suspension images. When the trigger time is reached, an analog signal is generated to trigger the contact suspension imaging unit to capture images. The analog signal is amplified and sent to the contact suspension imaging unit. The minimum trigger time interval for the contact suspension imaging unit to acquire contact suspension images is determined based on the ratio of the minimum value to the speed of the overhead contact line inspection train. After the contact suspension imaging unit is triggered when the trigger time is reached, the generated analog signal to trigger the contact suspension imaging unit is blocked within the minimum trigger time interval.

[0060] When the contact suspension imaging unit receives an analog signal, it takes a picture and stores the picture result.

[0061] This embodiment employs a high-speed camera and a synchronously triggered supplementary lighting system to perform full-coverage imaging of the contact suspension clamps. Using image enhancement and deep learning algorithms, it accurately identifies and locates the contact suspension clamps in all states. Simultaneously, based on train speed, it performs high-definition triggered imaging of the overhead contact line suspension. Specifically:

[0062] 1) High-speed full-coverage imaging and synchronous light source supplement: A high frame rate camera is used, paired with a precisely synchronized modulated light source, to ensure that the high-speed acquisition unit can perform full-coverage imaging of the contact suspension clamp under various environmental conditions, and no trigger signals received by the imaging unit are missed.

[0063] 2) Image enhancement and deep learning for accurate recognition: Image enhancement preprocessing techniques are used, including Gaussian filtering to remove noise (such as light spots and reflections) and histogram equalization to improve contrast. Combined with a YOLOv5-based deep learning model, the accuracy of recognition and positioning of suspension components under all conditions is significantly improved through transfer learning on the feature dataset of contact suspension clamps.

[0064] 3) Intelligent speed-adaptive trigger imaging: The vehicle travel distance is calculated based on the vehicle speed. Combined with the distance between the contact suspensions and the geometric positional relationship between the high-speed acquisition unit and the shooting unit, the shooting unit is dynamically positioned and triggered to ensure precise triggering timing, so that the contact suspension is always in the center of the image captured by the shooting unit.

[0065] 4) High-efficiency signal processing and high-resolution imaging: The integrated high-performance signal processing unit amplifies and accurately transmits the trigger signal to the imaging unit, triggering two 25-megapixel high-definition cameras to simultaneously acquire ultra-high-resolution images of the front and back of the contact suspension, providing accuracy assurance for subsequent defect detection.

[0066] This embodiment preprocesses the acquired contact suspension images to enhance image quality, introduces a deep learning model to extract features from the contact suspension clamps, and then uses a convolutional neural network to accurately identify the contact suspension clamps. This achieves accurate positioning and identification of contact suspensions in all states, solving the problem of missed detection of abnormal contact suspensions (such as detachment, breakage, and loss). Specifically:

[0067] 1) Image preprocessing techniques improve image quality: Image enhancement preprocessing algorithms are used to effectively suppress environmental noise (such as glare and vibration interference), optimize image clarity and contrast under different lighting and complex backgrounds, and ensure that high-quality and reliable data are provided for subsequent analysis.

[0068] 2) Deep learning feature extraction and accurate recognition: By using the YOLOv5 convolutional neural network and combining it with transfer learning for the features of the contact suspension clamp, high-precision recognition and positioning of contact suspension in all states (normal, detached, broken, lost) can be achieved, completely solving the problem of missed recognition caused by the looseness, detachment, and breakage of the contact suspension when directly identifying the contact suspension in the traditional way.

[0069] 3) Breakthrough in accurate detection of abnormal conditions: Unlike the method of directly identifying the suspension of the overhead contact line, the feature extraction and identification technology of the contact suspension clamps ensures comprehensive detection of abnormal contact suspension conditions (such as detachment, breakage, and loss), significantly improving the reliability and robustness of the detection.

[0070] 4) Systematic and precise positioning and efficient integration: It integrates high-speed image acquisition, intelligent image processing and trigger-based high-definition imaging technology to achieve precise positioning of contact suspension, eliminate redundant data and improve detection efficiency. At the same time, the modular system design can be seamlessly integrated into existing 4C detection equipment.

[0071] The system in this embodiment has the following technical effects and advantages:

[0072] 1. Avoid the acquisition of invalid and redundant data by the camera unit.

[0073] 1) Intelligent triggering mechanism reduces invalid images:

[0074] The system calculates the vehicle's travel distance based on its speed, and combines this with the spacing between the contact suspensions and the geometric positional relationship between the high-speed acquisition unit and the imaging unit to precisely calculate the shortest time interval for the trigger signal. The high-definition camera is triggered only when the contact suspension is centered in the image. This positioning-triggered imaging method avoids the generation of a large number of irrelevant and repetitive images, significantly reducing redundant data.

[0075] 2) High-efficiency target detection and signal optimization:

[0076] The image recognition processing unit quickly locates the contact suspension clamp using the YOLOv5 model, and only processes and triggers signals on images containing the contact suspension clamp; images of invalid areas are directly filtered out. This target-oriented processing method significantly reduces the generation of useless data.

[0077] 3) Modular system design focuses on key information:

[0078] The system employs a collaborative approach between a high-speed acquisition unit and an imaging unit. The high-speed acquisition unit performs full-coverage imaging only on key areas (contact suspension clamps and connecting wires), while the imaging unit performs high-definition imaging of specific points within the contact suspension area, rather than continuously and indiscriminately capturing the entire contact network. This modular design ensures that data acquisition focuses on relevant information, avoiding the massive amounts of redundant data generated by continuous full-coverage imaging in traditional methods.

[0079] 2. Accurate positioning of the contact suspension in the state of detachment, breakage, or loss is achieved by recognizing the wire clamp.

[0080] 1) High-speed full-coverage imaging and geometric correction:

[0081] The system employs a high-speed camera combined with a synchronously modulated light source to ensure comprehensive and complete image acquisition of the contact suspension while the train is running at high speed. The camera's flat-field correction function corrects distortion in the acquired images, eliminating image distortion caused by different angles or object distances. This ensures highly accurate position and size information of the contact suspension clamps and connecting wires, providing a reliable data foundation for subsequent clamp identification and processing.

[0082] 2) Deep learning-driven accurate object detection:

[0083] By utilizing the YOLOv5 deep learning model and optimizing it with a feature dataset of contact wire clamps through transfer learning, the system can quickly and accurately identify the location of contact wire clamps and their connecting wires. The model exhibits high robustness to all states of contact wire clamps (normal, detached, broken, missing), and can accurately locate clamps even in complex backgrounds or abnormal conditions, thus solving the problem of missed identification caused by the looseness, detachment, or breakage of contact wire clamps when directly identifying them using traditional methods.

[0084] 3) Intelligent speed adaptive triggering mechanism:

[0085] The system calculates the vehicle's travel distance based on its speed, and dynamically calculates the frame rate and the timing of trigger signal transmission by combining the spacing between the contact suspensions and the geometric positional relationship between the high-speed acquisition unit and the imaging unit, ensuring that the contact suspensions are always centered in the image. This intelligent triggering mechanism greatly improves the accuracy of positioning and avoids image deviations caused by changes in train speed.

[0086] The system has a simple structure and can be seamlessly integrated into existing 4C testing equipment.

[0087] Example of contact suspension positioning and data acquisition method

[0088] The method of this embodiment includes, when the catenary inspection train is not running, obtaining in advance the actual distance in the direction of travel between the high-speed acquisition unit of the contact suspension set at the front and the shooting unit of the contact suspension set at the rear on the roof of the catenary inspection train, using the actual distance as the distance in the direction of travel between the center of vision of the high-speed acquisition unit of the contact suspension and the shooting unit of the contact suspension, and obtaining the minimum value of the distance between adjacent contact suspensions on the running line of the catenary inspection train.

[0089] During the operation of the overhead contact line inspection train, the train speed is acquired in real time. Images of the overhead contact line are acquired in real time through the high-speed acquisition unit of the contact suspension. The images are filtered and enhanced. The YOLOv5 model is used to detect contact suspension clamps in the filtered and enhanced images. When a contact suspension clamp is detected, the distance between the center point of the contact suspension clamp and the center point of the image in the direction of travel is determined and converted into an actual distance. The actual distance is added to the distance of the center of the field of view in the direction of travel and divided by the speed of the overhead contact line inspection train to determine the trigger time for the contact suspension imaging unit to acquire contact suspension images. When the trigger time is reached, an analog signal is generated to trigger the contact suspension imaging unit to capture images. The analog signal is amplified and sent to the contact suspension imaging unit. The minimum trigger time interval for the contact suspension imaging unit to acquire contact suspension images is determined based on the ratio of the minimum value to the speed of the overhead contact line inspection train. After the contact suspension imaging unit is triggered when the trigger time is reached, the generated analog signal to trigger the contact suspension imaging unit is blocked within the minimum trigger time interval.

[0090] When the contact suspension imaging unit receives an analog signal, it takes a picture and stores the picture result.

[0091] The method in this embodiment can be implemented using the contact suspension positioning and acquisition system described above. Specifically, the contact suspension positioning and acquisition system implements the contact suspension positioning and acquisition method process, which has been described in detail in the contact suspension positioning and acquisition system embodiment and will not be repeated here.

[0092] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A contact suspension positioning and data acquisition method, characterized in that, Includes the following steps: When the overhead contact line inspection train is not running, the actual distance between the high-speed acquisition unit of the contact suspension at the front and the shooting unit of the contact suspension at the rear, which are set on the roof of the overhead contact line inspection train, in the direction of travel is obtained in advance. This actual distance is taken as the distance between the center of vision of the high-speed acquisition unit of the contact suspension and the shooting unit of the contact suspension in the direction of travel. During the operation of the overhead contact line inspection train, the train speed is acquired in real time, and images of the overhead contact line are acquired in real time through the high-speed acquisition unit of the contact suspension. The images of the overhead contact line are then identified. When a contact suspension clamp is identified, the corresponding image of the overhead contact line is identified in the contact suspension area, and the trigger time for the contact suspension imaging unit to acquire the contact suspension image is determined. The determination of the trigger time includes: determining the distance between the center point of the contact suspension clamp and the center point of the image in the direction of travel, converting the distance into an actual distance, and obtaining the trigger time by adding the actual distance to the distance of the center of the field of view in the direction of travel and dividing the sum by the speed of the contact wire detection train. When the trigger time is reached, the contact suspension imaging unit is triggered to control the contact suspension imaging unit to take pictures of the contact suspension and store the picture results.

2. The contact suspension positioning and acquisition method according to claim 1, characterized in that, Also includes: Before the overhead contact line inspection train is in operation, obtain the minimum value of the distance between adjacent contact suspensions on the line in which the overhead contact line inspection train is operating; When the overhead contact line inspection train is running, the minimum trigger time interval for triggering the contact suspension imaging unit to acquire contact suspension images is determined based on the ratio of the minimum value to the train's running speed. After the contact suspension imaging unit is triggered when the trigger time is reached, the operation of triggering the contact suspension imaging unit is blocked within the minimum trigger time interval.

3. The contact suspension positioning and acquisition method according to claim 2, characterized in that, Triggering the contact suspension imaging unit when the trigger time is reached includes: generating an analog signal that triggers the contact suspension imaging unit to capture images when the trigger time is reached, amplifying the analog signal and sending the amplified analog signal to the contact suspension imaging unit. Within the minimum trigger time interval, shielding the operation that triggers the contact suspension imaging unit includes: shielding the generated analog signal that triggers the contact suspension imaging unit to capture images within the minimum trigger time interval.

4. The contact suspension positioning and acquisition method according to claim 1, characterized in that, The formula for calculating the trigger time is: T=[L+M(X1-X2)] / V, where T is the trigger time, L is the distance between the center of vision of the contact suspension high-speed acquisition unit and the contact suspension shooting unit in the direction of travel, M is the actual distance represented by a single pixel in the image in the direction of travel, X1 is the coordinate of the center point of the contact suspension clamp in the direction of travel in the image, X2 is the coordinate of the center point of the image in the direction of travel in the image, and V is the speed of the contact wire detection train.

5. The contact suspension positioning and acquisition method according to claim 1, characterized in that, The identification of the contact wire image includes: filtering and enhancing the contact wire image to eliminate interference data in the image and improve the image clarity and contrast; and using the YOLOv5 model to detect the contact suspension clamps in the filtered and enhanced image.

6. A contact suspension positioning and acquisition system, characterized in that, It includes a high-speed acquisition unit for contact suspension, a shooting unit for contact suspension, an image processing unit, and a signal processing unit. With the driving direction as the forward direction, the high-speed acquisition unit for contact suspension is located in front of the shooting unit for contact suspension. The acquisition surfaces of both the high-speed acquisition unit for contact suspension and the shooting unit for contact suspension are perpendicular to the driving direction and are oriented towards the direction where the contact wire is located. The high-speed acquisition unit for the contact suspension is used to acquire images of the contact network in real time during the operation of the contact network inspection train, and transmit the images to the image processing unit; When the overhead contact line inspection train is not running, the image processing unit stores the actual distance between the high-speed acquisition unit and the shooting unit in the direction of travel as the distance between the center of view of the high-speed acquisition unit and the shooting unit in the direction of travel. When the overhead contact line inspection train is running, the image processing unit receives an image of the overhead contact line and identifies the image. When a contact suspension clamp is identified, the corresponding image of the overhead contact line is identified as being in the contact suspension area, and a trigger time is determined to trigger the shooting unit to acquire the contact suspension image. When the trigger time is reached, a trigger signal is transmitted to the signal processing unit. The determination of the trigger time includes: determining the distance between the center point of the contact suspension clamp in the direction of travel and the center point of the image in the image, converting this distance into an actual distance, and obtaining the trigger time by adding the actual distance to the distance of the center of view in the direction of travel and dividing the sum by the speed of the overhead contact line inspection train at this time. The signal processing unit is used to process the trigger signal and then transmit it to the contact suspension shooting unit; The contact suspension imaging unit is used to take pictures of the contact suspension and store the pictures when a trigger signal is received.

7. The suspended positioning and acquisition system according to claim 6, characterized in that, When the overhead contact line inspection train is not running, the image processing unit also stores the minimum value of the distance between adjacent contact suspensions on the line where the overhead contact line inspection train is running; when the overhead contact line inspection train is running, the image processing unit determines the minimum trigger time interval for triggering the contact suspension imaging unit to acquire contact suspension images based on the ratio of the minimum value to the speed of the overhead contact line inspection train, and after triggering the contact suspension imaging unit when the trigger time is reached, the operation of triggering the contact suspension imaging unit is blocked within the minimum trigger time interval.

8. The suspended positioning and acquisition system according to claim 7, characterized in that, The trigger signal is an analog signal, and processing the trigger signal includes amplifying the analog signal. Within the minimum trigger time interval, shielding the operation that triggers the contact suspension imaging unit includes: shielding the generated analog signal that triggers the contact suspension imaging unit to capture images within the minimum trigger time interval.

9. The suspended positioning and acquisition system according to claim 6, characterized in that, The formula for calculating the trigger time is: T=[L+M(X1-X2)] / V, where T is the trigger time, L is the distance between the center of vision of the contact suspension high-speed acquisition unit and the contact suspension shooting unit in the direction of travel, M is the actual distance represented by a single pixel in the image in the direction of travel, X1 is the coordinate of the center point of the contact suspension clamp in the direction of travel in the image, X2 is the coordinate of the center point of the image in the direction of travel in the image, and V is the speed of the contact wire detection train.

10. The suspended positioning and acquisition system according to claim 6, characterized in that, The identification of the contact wire image includes: filtering and enhancing the contact wire image to eliminate interference data in the image and improve the image clarity and contrast; and using the YOLOv5 model to detect the contact suspension clamps in the filtered and enhanced image.

Images