An ultrasonic nondestructive testing device for high-speed rail transit rail safety monitoring

Abstract

This invention relates to the field of rail inspection technology and discloses an ultrasonic non-destructive testing device for safety monitoring of rails in high-speed rail transit. The device includes: a support frame, shaped like a groove; an ultrasonic detector disposed within the support frame; two rail wheels fixed to the bottom centerline of the support frame; the travel controller mounted on the support frame and used to control the travel speed of the rail wheels; a first telescopic movement unit disposed on one side of the two rail wheels; a second telescopic movement unit disposed on the side of the two rail wheels away from the first telescopic movement unit; and a control module electrically connected to the ultrasonic detector and the travel controller, the control module being used to control the travel controller based on the ultrasonic signals collected by the ultrasonic detector. This invention achieves coordinated optimization of detection and motion.

Description

Technical Field

[0001] This invention relates to the field of rail inspection technology, and more specifically, to an ultrasonic non-destructive testing device for safety monitoring of rails in high-speed rail transit. Background Technology

[0002] During long-term service, high-speed rail tracks are prone to internal defects such as railhead damage, railbed cracks, and rail web fatigue due to repeated wheel-rail interactions, seriously threatening operational safety. Therefore, regular non-destructive testing of rails is a crucial step in ensuring the safe operation of rail transit.

[0003] Currently, the most commonly used non-destructive testing method for rails is ultrasonic testing. Ultrasonic testing is widely used in rail flaw detection operations due to its sensitivity to internal volumetric defects and its large detection depth. Existing ultrasonic testing devices are mainly divided into two categories: one is large rail flaw detection vehicles, which integrate multi-channel ultrasonic probes and can automatically travel along the rails to perform inspections. However, these devices are bulky, expensive, and require a dedicated track working window, making them difficult to apply to daily inspections or rapid inspections of local sections of the line. The other category is handheld ultrasonic flaw detectors, where the probe is manually held and scanned section by section along the rail. This method is flexible and convenient, but has low detection efficiency, high labor intensity, and the consistency of the detection path is difficult to guarantee, easily leading to missed detections or misjudgments due to human factors.

[0004] To address the aforementioned issues, some existing technologies disclose small inspection trolleys that can straddle rails, relying on rail wheels for guidance and equipped with drive wheels for autonomous movement. However, such devices still have the following shortcomings in practical applications: placing and removing the device from the rails is cumbersome, typically requiring the entire device to be inserted from one end of the rail or lifted with auxiliary tools, resulting in low assembly and disassembly efficiency and hindering rapid transfer across multiple sections; most devices lack closed-loop control capabilities to automatically adjust the travel speed based on real-time detection signals, and cannot respond autonomously when encountering defects or obstacles, posing a risk of collision or insufficient detection data integrity.

[0005] Therefore, it is necessary to provide an ultrasonic non-destructive testing device for the safety monitoring of rails in high-speed rail transit to solve the problems of existing small inspection trolleys straddling rails, which have cumbersome placement and removal operations, low disassembly and assembly efficiency, are not conducive to rapid transfer of multiple sections, lack closed-loop control capability to automatically adjust the travel speed based on real-time detection signals, and cannot respond autonomously when encountering defects or obstacles, resulting in collision risks or insufficient integrity of detection data. Summary of the Invention

[0006] In view of this, the present invention proposes an ultrasonic non-destructive testing device for safety monitoring of rails in high-speed rail transit. It aims to solve the problems of existing small inspection trolleys straddling rails, which have cumbersome placement and removal operations, low disassembly and assembly efficiency, are not conducive to rapid transfer of multiple sections, lack closed-loop control capability to automatically adjust the travel speed based on real-time detection signals, and cannot respond autonomously when encountering defects or obstacles, resulting in collision risks or insufficient integrity of detection data.

[0007] This invention proposes an ultrasonic non-destructive testing device for safety monitoring of rails in high-speed rail transit, comprising: The support frame is groove-shaped; An ultrasonic detector is installed inside the support frame; The system includes two rail wheels, which are fixed to the bottom centerline of the support frame. The travel controller is mounted on the support frame and is used to control the travel speed of the rail wheels. The first telescopic moving unit is disposed on one side of the two rail wheels, and the top of the first telescopic moving unit is fixed on the support frame; the first telescopic moving unit includes two first telescopic rods, two first traveling wheels and a first controller, the first telescopic rods are fixed on the support frame, the first traveling wheels are fixed at the end of the first telescopic rod away from the support frame, and the first controller is electrically connected to the first telescopic rods to control the extension and retraction of the two first telescopic rods; The second telescopic moving unit is disposed on the side of the two rail wheels away from the first telescopic moving unit, and the top of the second telescopic moving unit is fixed on the support frame; the second telescopic moving unit includes two second telescopic rods, two second traveling wheels and a second controller, the second telescopic rods are fixed on the support frame, the second traveling wheels are fixed at the end of the second telescopic rod away from the support frame, and the second controller is electrically connected to the second telescopic rods to control the extension and retraction of the two second telescopic rods; The control module is electrically connected to the ultrasonic detector and the driving controller. The control module is used to control the driving controller based on the ultrasonic signals collected by the ultrasonic detector.

[0008] Furthermore, the control module includes: The acquisition unit is used to acquire ultrasonic signals and the travel speed of the rail wheels; The defect judgment unit is used to determine whether there are defects or obstacles in the rail based on the ultrasonic signal. If there are defects, the defect level is judged. If there are obstacles, an obstacle warning is issued. A speed control unit is used to send speed control signals to the driving controller according to the defect level and obstacle level to adjust the driving speed.

[0009] Furthermore, when the defect judgment unit is used to determine whether there are defects or obstacles in the rail based on the ultrasonic signal, it includes: The ultrasonic signal is filtered, amplified, and converted from analog to digital to obtain a digital echo signal; Extract the echo features of the digital echo signal; wherein the echo features include amplitude features, propagation time features, and spectral features; The extracted echo features are compared with a preset database of rail reference features that are free of defects and obstacles. The deviation is calculated, and the presence of defects or obstacles in the rail is determined based on the deviation.

[0010] Furthermore, when determining whether there are defects or obstacles in the rail based on the deviation, the following steps are included: When the deviation exceeds a preset first defect threshold, a defect is determined to exist, and the defect level is classified as minor defect, medium defect, or severe defect according to the magnitude of the deviation. When an abnormal peak of non-rail echo appears in the digital echo signal, and the amplitude of the abnormal peak exceeds a preset second obstacle threshold and the duration exceeds a preset time window, an obstacle is determined to exist.

[0011] Furthermore, when the speed control unit sends a speed control signal to the driving controller based on the defect level and obstacle level to adjust the driving speed, it includes: If an obstacle is detected, an emergency braking signal is sent to the driving controller to stop the rail wheels. At the same time, the obstacle location and warning information are sent to the remote monitoring center through the communication unit built into the control module.

[0012] Furthermore, when the speed control unit is used to send a speed control signal to the driving controller according to the defect level and obstacle level to adjust the driving speed, it further includes: If a minor defect is detected, a speed reduction signal is sent to the driving controller to reduce the driving speed to a preset first safe speed. If a moderate defect is determined to exist, a further deceleration signal is sent to the driving controller to reduce the driving speed to a preset second safe speed; wherein the second safe speed is lower than the first safe speed; If a serious defect is determined to exist, an emergency deceleration signal is sent to the driving controller to the minimum safe crawl speed, which is lower than the second safe speed. When a defect is detected, the defect location, defect level, and detection data are sent to the remote monitoring center via the communication unit. After the vehicle leaves the defect area, the driving speed is restored. The detection data includes ultrasonic signals, digital echo signals, and echo characteristics.

[0013] Furthermore, when the defect level is medium or severe, the detection data is verified. The driving controller is controlled to make the ultrasonic detector travel back and forth in the defect section at least once, and the sampling frequency of the ultrasonic detector is adjusted to re-acquire the ultrasonic signal to obtain re-inspection data. The re-inspection data is compared with the detection data, and the latest defect level is determined based on the comparison results.

[0014] Furthermore, adjusting the sampling frequency of the ultrasonic detector includes: The adjusted sampling frequency is higher than the original sampling frequency; among which, The sampling frequency multiplier is determined based on the defect level: if the defect level is medium, the sampling frequency is increased to twice the initial detection sampling frequency; if the defect level is severe, the sampling frequency is increased to four times the initial detection sampling frequency. After the verification is completed, the initial detection sampling frequency will be restored.

[0015] Furthermore, when determining the latest defect level based on the comparison results, the process includes: If the defect level determined based on the re-inspection data is consistent with the initial defect level, then the initial defect level will be the latest defect level. If the defect level determined based on the re-inspection data is inconsistent with the initial defect level, the defect level determined based on the re-inspection data will be the latest defect level.

[0016] Furthermore, the ultrasonic non-destructive testing device for high-speed rail safety monitoring also includes a telescopic handle, which is fixed to one side of the support frame; The telescopic handle includes a telescopic rod and an anti-slip handrail. The bottom of the telescopic rod is fixed to the support frame, and the anti-slip handrail is fixed to the end of the telescopic rod away from the support frame.

[0017] Compared with existing technologies, the advantages of this invention are as follows: The support frame is grooved, providing a mounting base for the ultrasonic detector. Two rail wheels are fixed to the bottom centerline of the support frame, ensuring that the device remains aligned with the longitudinal centerline of the rail as it rolls along the top surface, avoiding blind spots in detection. When placing the device, firstly, the first or second telescopic rod is retracted, lifting the first or second traveling wheel off the top surface of the rail, completing rapid alignment and straddle installation of the device on the rail. After alignment, both the first and second telescopic rods are retracted, and the operator controls the device's direction of travel. When removing the device from the rail, the first or second telescopic rod is extended again, causing the first or second traveling wheel to slide the rail wheel off the rail. Then, both the first and second telescopic rods are extended, improving ease of assembly and disassembly. The control module forms a detection-motion closed loop, adjusting the travel speed in real time based on the ultrasonic signal to achieve coordinated optimization of detection and motion. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the ultrasonic non-destructive testing device for high-speed rail safety monitoring provided in an embodiment of the present invention; Figure 2 A functional block diagram of the control module provided in an embodiment of the present invention.

[0019] In the diagram: 100, support frame; 200, ultrasonic detector; 310, rail wheel; 320, travel controller; 400, first telescopic moving unit; 410, first telescopic pole; 420, first traveling wheel; 430, first controller; 500, second telescopic moving unit; 510, second telescopic pole; 520, second traveling wheel; 530, second controller; 600, telescopic handle; 610, telescopic pole body; 620, anti-slip handrail. Detailed Implementation

[0020] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] In some embodiments of this application, see Figure 1 As shown, this embodiment provides an ultrasonic non-destructive testing device for safety monitoring of rails in high-speed rail transit, comprising: The support frame 100 is groove-shaped; An ultrasonic detector 200 is disposed within the support frame 100; The system includes two rail wheels 310, which are fixed to the bottom centerline of the support frame 100. The travel controller 320 is mounted on the support frame 100 and is used to control the travel speed of the rail wheels 310. A first telescopic moving unit 400 is disposed on one side of the two rail wheels 310, and the top of the first telescopic moving unit 400 is fixed on the support frame 100; the first telescopic moving unit 400 includes two first telescopic rods 410, two first traveling wheels 420 and a first controller 430, the first telescopic rods 410 are fixed on the support frame 100, the first traveling wheels 420 are fixed at the end of the first telescopic rods 410 away from the support frame 100, and the first controller 430 is electrically connected to the first telescopic rods 410 to control the extension and retraction of the two first telescopic rods 410; The second telescopic moving unit 500 is disposed on the side of the two rail wheels 310 away from the first telescopic moving unit 400, and the top of the second telescopic moving unit 500 is fixed on the support frame 100; the second telescopic moving unit 500 includes two second telescopic rods 510, two second traveling wheels 520 and a second controller 530, the second telescopic rods 510 are fixed on the support frame 100, the second traveling wheels 520 are fixed at the end of the second telescopic rods 510 away from the support frame 100, and the second controller 530 is electrically connected to the second telescopic rods 510 to control the extension and retraction of the two second telescopic rods 510; The control module is electrically connected to the ultrasonic detector 200 and the driving controller 320. The control module is used to control the driving controller 320 according to the ultrasonic signals collected by the ultrasonic detector 200.

[0022] Understandably, the support frame 100 is groove-shaped, providing a mounting base for the ultrasonic detector 200. Two rail wheels 310 are fixed to the bottom centerline of the support frame 100, ensuring the device remains aligned with the longitudinal centerline of the rail as it rolls along the top surface, avoiding blind spots. When placing the device, first control the retraction of the first telescopic rod 410 or the second telescopic rod 510, lifting the first traveling wheel 420 or the second traveling wheel 520 off the top surface of the rail, completing the rapid alignment and straddle installation of the device on the rail. After alignment, both the first telescopic rod 410 and the second telescopic rod 510 are retracted, and the operator controls the device's direction of travel. When removing the device from the rail, the first telescopic rod 410 or the second telescopic rod 510 is extended again, causing the first traveling wheel 420 or the second traveling wheel 520 to slide the rail wheels 310 off the rail. Then, both the first telescopic rod 410 and the second telescopic rod 510 are extended, improving ease of assembly and disassembly. The control module forms a detection-motion closed loop, adjusting the driving speed in real time based on ultrasonic signals to achieve coordinated optimization of detection and motion.

[0023] In practical implementation, the device is first placed on one side of the rail to be tested. The control module drives the first telescopic rod 410 or the second telescopic rod 510 to retract through the first controller 430 or the second controller 530, so that the two traveling wheels on the corresponding side are lifted off the top surface of the rail. At this time, the device only relies on the traveling wheel on the other side and the two rail wheels 310 for temporary support. The operator slides the device in from the side of the lifting wheel along the lateral direction, so that the two rail wheels 310 are accurately straddled on the center line of the top surface of the rail, completing the quick alignment and straddle installation. After the alignment is completed, the control module instructs the first telescopic rod 410 and the second telescopic rod 510 to retract, so that all traveling wheels on the left and right sides are further lifted off the top surface of the rail and the surface of the sleeper. At this time, the device is completely supported by the two rail wheels 310. The operator sets the running direction through the control module and drives the rail wheels 310 to roll along the top surface of the rail, driving the device forward. During operation, the ultrasonic detector 200 continuously emits ultrasonic pulses into the rail and receives echo signals. The control module collects the echo signals in real time and compares them with preset defect-free benchmark features. When the echo signal is normal, the current travel state is maintained. When the echo signal shows abnormal features, the control module determines the type and level of the abnormality and sends a speed adjustment command to the travel controller 320, realizing closed-loop collaborative optimization of detection and motion behavior. After the detection operation is completed, the control module commands the first telescopic rod 410 or the second telescopic rod 510 to extend, causing the corresponding side traveling wheel to extend downward and contact the sleeper or track bed surface. Using the support force provided by the traveling wheel on that side, the rail wheel 310 slides off the rail. Subsequently, the control module commands both the first telescopic rod 410 and the second telescopic rod 510 to extend, so that the traveling wheels on both sides are fully extended, making it easy for the operator to remove the device from the rail and push it to the next inspection section.

[0024] See Figure 2As shown, in some specific embodiments of this application, the control module includes: The acquisition unit is used to acquire ultrasonic signals and the travel speed of the rail wheel 310; The defect judgment unit is used to determine whether there are defects or obstacles in the rail based on the ultrasonic signal. If there are defects, the defect level is judged. If there are obstacles, an obstacle warning is issued. A speed control unit is used to send a speed control signal to the driving controller 320 according to the defect level and obstacle level to adjust the driving speed.

[0025] Understandably, by setting up an acquisition unit to simultaneously acquire ultrasonic detection signals and the speed of the traveling wheels, the device can simultaneously grasp the internal state of the rail and its own motion parameters during the detection process, providing a data basis for subsequent judgment and control. The defect judgment unit performs real-time analysis of the ultrasonic signals, which can not only automatically identify whether there are defects or obstacles in the rail, but also further distinguish the defect level or provide obstacle warnings, avoiding the lag and subjective errors of manual interpretation. The speed control unit sends the corresponding speed adjustment signal to the travel controller 320 based on the level results output by the defect judgment unit, realizing the instant feedback and closed-loop adjustment of the motion behavior by the detection results.

[0026] In some specific embodiments of this application, when the defect judgment unit is used to determine whether there is a defect or obstacle in the rail based on the ultrasonic signal, it includes: The ultrasonic signal is filtered, amplified, and converted from analog to digital to obtain a digital echo signal; Extract the echo features of the digital echo signal; wherein the echo features include amplitude features, propagation time features, and spectral features; The extracted echo features are compared with a preset database of rail reference features that are free of defects and obstacles. The deviation is calculated, and the presence of defects or obstacles in the rail is determined based on the deviation.

[0027] Understandably, the original ultrasonic signal is first filtered, amplified, and converted from analog to digital to eliminate environmental noise and circuit interference, converting it into a processable digital echo signal. Then, amplitude features, propagation time features, and spectral features are extracted from the digital echo signal. These three dimensions reflect echo intensity, defect depth / distance, and frequency response caused by material changes, respectively. Finally, the extracted fused features are compared item by item with a pre-established database of defect-free and obstacle-free rail reference features. The comprehensive deviation is calculated, and the presence of defects or obstacles in the rail is determined based on whether the deviation exceeds a threshold. Filtering, amplification, and analog-to-digital conversion improve signal quality and avoid misjudgments; multi-dimensional feature extraction can distinguish different types of anomalies (such as internal cracks, railhead damage, or foreign objects in the ballast bed), enhancing identification accuracy; and the comparison with the reference feature database enables quantitative and standardized automatic judgment, eliminating the differences in human experience, thereby improving the reliability and real-time performance of rail safety monitoring.

[0028] In some specific embodiments of this application, determining whether there is a defect or obstruction in the rail based on the deviation includes: When the deviation exceeds a preset first defect threshold, a defect is determined to exist, and the defect level is classified as minor defect, medium defect, or severe defect according to the magnitude of the deviation. When an abnormal peak of non-rail echo appears in the digital echo signal, and the amplitude of the abnormal peak exceeds a preset second obstacle threshold and the duration exceeds a preset time window, an obstacle is determined to exist.

[0029] Understandably, by setting independent defect thresholds and obstacle thresholds, it is possible to accurately distinguish between internal material defects in the rail and external foreign objects on the rail surface, avoiding misreporting ballast, snow accumulation, etc., as rail damage; at the same time, the defect level classification can provide a quantitative basis for subsequent speed control, enabling differentiated responses.

[0030] In the specific implementation process, the deviation of the defect-free benchmark feature library is normalized to the range of 0~100, and the first defect threshold is set to 15: when the deviation is between 15 and 30, it is judged as a minor defect; 30~60 is a moderate defect; and greater than 60 is a severe defect. For obstacle judgment, echo samples of typical stones, ballast, or rail surface oil are collected in advance, and their minimum amplitude is set as the second obstacle threshold (e.g., 1.5 times the amplitude of the benchmark echo). The upper limit of the duration of short-term interference (e.g., instantaneous electrical noise) is set as a preset time window (e.g., 5 milliseconds). Only when the abnormal peak simultaneously meets the condition of exceeding the threshold in amplitude and lasting for more than 5 milliseconds is it confirmed as a real obstacle, thereby effectively suppressing false triggering. Specifically, the specific values ​​of the above-mentioned first and second defect thresholds can be determined through offline calibration experiments based on the rail material, detection frequency, and on-site working conditions, and are pre-stored in the control module.

[0031] Specifically, in the process of normalizing the deviation of the defect-free reference feature library to the range of 0-100, multiple ultrasonic tests are first performed on a standard rail section that is defect-free and free of obstructions to collect a large number of reference echo signals. Three types of features are extracted: amplitude, propagation time, and spectrum. The mean and standard deviation of each feature are calculated to construct a multi-dimensional reference feature vector. Then, for the echo features extracted from the actual tests, the Mahalanobis or Euclidean distance between them and the reference feature vector is calculated as the original deviation. To map this deviation to the continuous range of 0-100, the lower limit (corresponding to a completely defect-free state, usually set to 0) and upper limit (corresponding to the equivalent of a standard artificial defect such as a Φ2mm flat-bottomed hole, with the deviation set to 100) of the deviation are determined in advance through field experiments. The lower limit of the deviation is the average deviation obtained from multiple tests on the defect-free section (usually close to 0), and the upper limit of the deviation is the average deviation obtained from repeated tests on the artificially defective sample plus three times the standard deviation. If the original deviation is below the lower limit, it is taken as 0; if it is above the upper limit, it is taken as 100. This quantifies all possible defect responses into the range of 0 to 100, which facilitates the subsequent defect level classification (e.g., below 15 no defects, 15 to 30 slight defects, 30 to 60 moderate defects, and above 60 severe defects).

[0032] In some specific embodiments of this application, when the speed control unit is used to send a speed control signal to the driving controller 320 according to the defect level and obstacle level to adjust the driving speed, it includes: If an obstacle is detected, an emergency braking signal is sent to the driving controller 320 to stop the rail wheel 310 from moving. At the same time, the obstacle location and warning information are sent to the remote monitoring center through the communication unit built into the control module.

[0033] Understandably, on the one hand, emergency braking can stop the device before it comes into contact with an obstacle, preventing the rail wheel 310 from colliding with or straddling the obstacle, thereby preventing the device from overturning, derailing, or the ultrasonic detector 200 from being damaged, ensuring the safety and continuous operation capability of the equipment itself; on the other hand, sending the obstacle location and early warning information to the remote monitoring center in real time allows maintenance personnel to be aware of line abnormalities in a timely manner and arrange for manual removal or detour handling, thereby effectively reducing the risk of train operation safety accidents caused by foreign objects on the rail surface, and realizing the organic combination of the detection device's own active protection and line safety early warning.

[0034] In practice, the device is manually pushed by the operator, moving along the rail at a speed of 2 km / h (approximately 0.56 m / s). The ultrasonic detector 200 continuously emits pulses towards the rail surface. When an abnormal peak appears in the digital echo signal with an amplitude exceeding a preset second obstacle threshold (e.g., 2.5 times the normal rail surface echo amplitude) and a duration exceeding 5 milliseconds, the defect judgment unit identifies it as an obstacle and controls the device to stop. The 4G / 5G communication unit built into the control module sends the current GPS / BeiDou location coordinates, timestamp, and "rail surface obstacle" warning type to the remote monitoring center. After the obstacle is cleared, the monitoring center can remotely send a reset command, and the device resumes normal detection operations.

[0035] In some specific embodiments of this application, when the speed control unit is used to send a speed control signal to the driving controller 320 according to the defect level and obstacle level to adjust the driving speed, it further includes: If a minor defect is detected, a speed reduction signal is sent to the driving controller 320 to reduce the driving speed to a preset first safe speed. If a moderate defect is determined to exist, a further deceleration signal is sent to the driving controller 320 to reduce the driving speed to a preset second safe speed; wherein the second safe speed is lower than the first safe speed; If a serious defect is determined to exist, an emergency deceleration signal is sent to the driving controller 320 to the minimum safe crawl speed, wherein the minimum safe crawl speed is lower than the second safe speed; When a defect is detected, the defect location, defect level, and detection data are sent to the remote monitoring center via the communication unit. After the vehicle leaves the defect area, the driving speed is restored. The detection data includes ultrasonic signals, digital echo signals, and echo characteristics.

[0036] Understandably, the graded speed reduction strategy can reasonably balance detection accuracy and operational efficiency according to the severity of defects. For minor defects, the speed is reduced appropriately to ensure data integrity without significantly affecting the progress. For moderate defects, the speed is further reduced to increase the ultrasonic sampling density. For severe defects, the vehicle passes through at a crawling speed to obtain the highest resolution echo signal, avoiding missed or false detections. After leaving the defect area, the speed is automatically restored, reducing manual intervention. The ultrasonic signal, digital echo signal, and echo characteristics are uploaded together, providing raw data support for remote expert review and historical comparison, thus improving the accuracy and traceability of rail damage characterization.

[0037] In practice, the device is manually steered by the operator and travels along the rail at a normal detection speed of 3 km / h (approximately 0.83 m / s). When the defect assessment unit determines that there is a railhead defect with a deviation of 28 at a weld (within the minor defect range of 15-30), the speed control unit sends a deceleration signal, reducing the travel speed to the first safe speed of 2 km / h (approximately 0.56 m / s). The device passes through the defect section at this speed and collects 500 A-type scan waveforms. After traveling 20 meters, the deviation falls below the threshold, and the speed automatically recovers to 3 km / h. Subsequently, a deviation of 65 (a serious defect) is detected on another curve section. The speed control unit immediately reduces the speed to the minimum safe creep speed of 0.5 km / h, and simultaneously packages the defect location (K125+340), the severity of the defect, and 100 consecutive frames of ultrasonic signals, digital echo signals, and spectral characteristics, and sends them to the monitoring center via 5G. After online analysis, the center engineers confirmed it to be a transverse crack at the rail base and immediately arranged for emergency repairs.

[0038] Furthermore, to ensure the signal-to-noise ratio and spatial resolution of ultrasonic testing, the driving speed must be matched with the sampling frequency and probe coverage width. The lower the speed, the more sampling points per unit length, and the stronger the ability to identify minute defects. Secondly, considering the controllability and safety of manual operation, the speed should be controlled within the range that the operator can stably push, stop in an emergency, and without generating dangerous inertia (usually 0.5km / h to 3km / h). Based on this, the first safe speed (e.g., 2 km / h) corresponds to minor defects. At this speed, the device travels at a speed slightly lower than the normal detection speed (3 km / h), which increases sampling density without significantly affecting overall efficiency, and is easily controllable by hand. The second safe speed (e.g., 1 km / h) corresponds to moderate defects. The speed is further reduced to increase the number of ultrasonic pulse transmission / reception cycles, obtaining richer echo details, while the operator can focus more on controlling the direction. The lowest safe crawling speed (e.g., 0.5 km / h) corresponds to severe defects. At this speed, the device is almost in a creeping state, allowing for repeated scanning of the defective section, minimizing vibration interference, ensuring coupling stability, and thus obtaining the highest confidence level of detection data. All of the above speed values ​​can be determined through field calibration experiments. On rail samples containing different equivalent artificial defects, repeated detections were performed at different speeds, and the defect detection rate and false alarm rate were statistically analyzed to ultimately determine the optimal upper limit of the speed for each level.

[0039] In some specific embodiments of this application, when the defect level is a medium defect or a severe defect, it is determined that the detection data should be verified, the driving controller 320 is controlled to make the ultrasonic detector 200 travel back and forth in the defect section at least once, and the sampling frequency of the ultrasonic detector 200 is adjusted to re-acquire ultrasonic signals to obtain re-inspection data. The re-inspection data is compared with the detection data, and the latest defect level is determined based on the comparison results.

[0040] Understandably, by conducting repeated inspections and sampling at higher frequencies, random errors caused by poor coupling, vibration noise, or transient interference in a single inspection can be effectively eliminated, resulting in more detailed and reliable echo signals. By comparing the initial inspection results with the re-inspection results, the level determined can avoid misjudging serious defects as medium defects, leading to insufficient maintenance, and also avoid misjudging medium defects as serious defects, leading to over-maintenance, thereby improving the accuracy, redundancy, and reliability of the device in determining critical defects.

[0041] In one specific embodiment, the device is manually operated by an operator at a normal speed of 2 km / h to inspect the rails. An initial inspection at a railhead yields a deviation of 45 (within the medium defect range of 30-60), and the control module records the defect start and end points as K12+100 to K12+108. Upon receiving a re-inspection command, the device retreats to K12+095 and then travels back and forth twice between K12+095 and K12+113 at a speed of 1 km / h. Simultaneously, the sampling frequency of the ultrasonic detector 200 is increased from the initial 2MHz to 4MHz (doubled), acquiring 600 A-type scan waveforms per round trip. The re-inspection data is compared frame-by-frame with the initial inspection data, revealing good consistency in echo amplitude and no significant drift in spectral characteristics. The average re-inspection deviation is calculated to be 47, still within the medium defect range, maintaining the original level. The device then sends a message "Confirmed as a medium defect after re-inspection" along with the re-inspection waveform data to the remote monitoring center via the communication unit. If the average deviation of the re-inspection rises to 68 (falling into the critical defect range), the level will be updated to critical defect and reported.

[0042] In some specific embodiments of this application, adjusting the sampling frequency of the ultrasonic detector 200 includes: The adjusted sampling frequency is higher than the original sampling frequency; among which, The sampling frequency multiplier is determined based on the defect level: if the defect level is medium, the sampling frequency is increased to twice the initial detection sampling frequency; if the defect level is severe, the sampling frequency is increased to four times the initial detection sampling frequency. After the verification is completed, the initial detection sampling frequency will be restored.

[0043] Understandably, by driving the sampling frequency differentially through defect level, the re-inspection process can obtain matching signal resolution for defects of different severity. Medium defects can be re-inspected with a 2x frequency without generating excessive data volume, while severe defects can be re-inspected with a 4x frequency to capture finer echo details (such as diffraction waves from microcracks), thus providing high-fidelity data for accurate verification of defect levels. At the same time, the initial frequency is restored in a timely manner after verification, avoiding the increased data storage pressure and power consumption caused by long-term high-frequency sampling, thus achieving an optimized balance between detection accuracy and resource consumption.

[0044] In a specific embodiment, the device initially inspects the rail at a sampling frequency of 2.5MHz, finding a deviation of 38 (moderate defect) at a certain location. The control module initiates a re-inspection, adjusting the sampling frequency of the ultrasonic detector 200 to 5MHz (doubled). It travels back and forth once through the defective section, acquiring 600 sets of A-type scan waveforms. The defect echo boundaries in the re-inspection waveforms are clear, and comparison confirms the defect level remains moderate. The device then exits the defective section, and the sampling frequency automatically returns to 2.5MHz. In another inspection, the initial deviation is 76 (severe defect). During the re-inspection, the sampling frequency is adjusted to 10MHz (four times). After two round trips, the high-frequency data clearly distinguishes the secondary reflection wave after the defect echo, confirming the defect as a transverse crack at the rail base extending to the rail web. The defect level is ultimately confirmed as severe. After the re-inspection, the sampling frequency returns to 2.5MHz, and the device continues inspection at normal speed.

[0045] In some specific embodiments of this application, determining the latest defect level based on the comparison results includes: If the defect level determined based on the re-inspection data is consistent with the initial defect level, then the initial defect level will be the latest defect level. If the defect level determined based on the re-inspection data is inconsistent with the initial defect level, the defect level determined based on the re-inspection data will be the latest defect level.

[0046] Understandably, independently verifying the initial inspection through re-inspection retains the rapid confirmation efficiency when the initial and re-inspections are consistent, while also providing a correction mechanism for discrepancies. When the re-inspection reveals a more severe defect, it avoids the safety hazard of insufficient repair; conversely, when the re-inspection finds that the initial inspection was over-judged, it prevents the waste of resources caused by excessive repair. This invention uses more reliable, higher-resolution re-inspection data as the final judgment basis, improving the accuracy, credibility, and rationality of defect level determination.

[0047] In a specific embodiment, the device detects a rail section at an initial sampling frequency of 2MHz. The initial deviation is 46, which is judged as a medium defect. After initiating a re-inspection, the sampling frequency is increased to 4MHz, and the device travels back and forth across the defective section once. The re-inspection data is analyzed and the average deviation is calculated to be 49, still within the medium defect range (30~60), consistent with the initial inspection level. Based on this, the control module determines the latest defect level as medium defect and maintains the original inspection plan. In another scenario, the initial inspection deviation is 54 (medium defect), but during the re-inspection, richer echo details are collected at 4MHz, and the calculated average deviation rises to 71 (severe defect), inconsistent with the initial inspection level. The control module updates the latest defect level to severe defect and sends the corrected level and re-inspection waveform data to the remote monitoring center through the communication unit. At the same time, the travel speed is further reduced to the minimum safe crawl speed of 0.5km / h. Conversely, if the initial inspection deviation is 73 (serious defect), and the re-inspection reveals that the abnormality is due to uneven coupling agent, and the average re-inspection deviation drops to 48 (medium defect), then the control module will adjust the latest defect level to medium defect.

[0048] In some specific embodiments of this application, the ultrasonic non-destructive testing device for high-speed rail transit rail safety monitoring also includes a telescopic handle 600, which is fixed to one side of the support frame 100. The telescopic handle 600 includes a telescopic rod 610 and an anti-slip handrail 620. The bottom of the telescopic rod 610 is fixed to the support frame 100. The anti-slip handrail 620 is fixed to the end of the telescopic rod 610 away from the support frame 100.

[0049] Understandably, the telescopic handle 600 provides operators with a stable handhold, facilitating manual pushing, lifting, and lateral sliding of the device. Especially during device placement, removal, and straddling alignment, the telescopic rod 610 can be adjusted in length according to the operator's height and working posture, preventing bending or overextension and reducing labor intensity. The anti-slip handle 620 enhances grip safety and prevents hand slippage. Simultaneously, the telescopic structure allows the handle to retract to its minimum length when not in use, reducing the overall size of the device and facilitating storage and transportation. This design significantly improves the device's human-machine interface and on-site operational convenience.

[0050] In a specific embodiment, the telescopic handle 600 uses two sections of stainless steel telescopic tubes, with the inner and outer tubes positioned by a spring-loaded locking pin. The telescopic range is adjustable, and the handrail is covered with rubber to form a non-slip handrail 620. When placing the device, the operator holds the telescopic handle 600 and slides the device into place from one side of the rail. After the inspection is completed, the operator retracts the telescopic rod 610.

[0051] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0052] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0053] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0054] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An ultrasonic non-destructive testing device for safety monitoring of rails in high-speed rail transit, characterized in that, include: The support frame is groove-shaped; An ultrasonic detector is installed inside the support frame; The system includes two rail wheels, which are fixed to the bottom centerline of the support frame. The travel controller is mounted on the support frame and is used to control the travel speed of the rail wheels. The first telescopic moving unit is disposed on one side of the two rail wheels, and the top of the first telescopic moving unit is fixed on the support frame; the first telescopic moving unit includes two first telescopic rods, two first traveling wheels and a first controller, the first telescopic rods are fixed on the support frame, the first traveling wheels are fixed at the end of the first telescopic rod away from the support frame, and the first controller is electrically connected to the first telescopic rods to control the extension and retraction of the two first telescopic rods; The second telescopic moving unit is disposed on the side of the two rail wheels away from the first telescopic moving unit, and the top of the second telescopic moving unit is fixed on the support frame; the second telescopic moving unit includes two second telescopic rods, two second traveling wheels and a second controller, the second telescopic rods are fixed on the support frame, the second traveling wheels are fixed at the end of the second telescopic rod away from the support frame, and the second controller is electrically connected to the second telescopic rods to control the extension and retraction of the two second telescopic rods; The control module is electrically connected to the ultrasonic detector and the driving controller. The control module is used to control the driving controller based on the ultrasonic signals collected by the ultrasonic detector.

2. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 1, characterized in that, The control module includes: The acquisition unit is used to acquire ultrasonic signals and the travel speed of the rail wheels; The defect judgment unit is used to determine whether there are defects or obstacles in the rail based on the ultrasonic signal. If there are defects, the defect level is judged. If there are obstacles, an obstacle warning is issued. A speed control unit is used to send speed control signals to the driving controller according to the defect level and obstacle level to adjust the driving speed.

3. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 2, characterized in that, The defect determination unit is used to determine whether there are defects or obstacles in the rail based on the ultrasonic signal, including: The ultrasonic signal is filtered, amplified, and converted from analog to digital to obtain a digital echo signal; Extract the echo features of the digital echo signal; wherein the echo features include amplitude features, propagation time features, and spectral features; The extracted echo features are compared with a preset database of rail reference features that are free of defects and obstacles. The deviation is calculated, and the presence of defects or obstacles in the rail is determined based on the deviation.

4. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 3, characterized in that, The process of determining whether there are defects or obstacles in the rail based on the deviation includes: When the deviation exceeds a preset first defect threshold, a defect is determined to exist, and the defect level is classified as minor defect, medium defect, or severe defect according to the magnitude of the deviation. When an abnormal peak of non-rail echo appears in the digital echo signal, and the amplitude of the abnormal peak exceeds a preset second obstacle threshold and the duration exceeds a preset time window, an obstacle is determined to exist.

5. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 2, characterized in that, The speed control unit, used to send speed control signals to the driving controller according to the defect level and obstacle level to adjust the driving speed, includes: If an obstacle is detected, an emergency braking signal is sent to the driving controller to stop the rail wheels. At the same time, the obstacle location and warning information are sent to the remote monitoring center through the communication unit built into the control module.

6. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 2, characterized in that, When the speed control unit is used to send a speed control signal to the driving controller according to the defect level and obstacle level to adjust the driving speed, it further includes: If a minor defect is detected, a speed reduction signal is sent to the driving controller to reduce the driving speed to a preset first safe speed. If a moderate defect is determined to exist, a further deceleration signal is sent to the driving controller to reduce the driving speed to a preset second safe speed; wherein the second safe speed is lower than the first safe speed; If a serious defect is determined to exist, an emergency deceleration signal is sent to the driving controller to the minimum safe crawl speed, which is lower than the second safe speed. When a defect is detected, the defect location, defect level, and detection data are sent to the remote monitoring center via the communication unit. After the vehicle leaves the defect area, the driving speed is restored. The detection data includes ultrasonic signals, digital echo signals, and echo characteristics.

7. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 6, characterized in that, When the defect level is medium or severe, the detection data is verified. The driving controller is controlled to make the ultrasonic detector travel back and forth in the defect section at least once, and the sampling frequency of the ultrasonic detector is adjusted to re-acquire the ultrasonic signal to obtain re-inspection data. The re-inspection data is compared with the detection data, and the latest defect level is determined based on the comparison result.

8. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 7, characterized in that, Adjusting the sampling frequency of the ultrasonic detector includes: The adjusted sampling frequency is higher than the original sampling frequency; among which, The sampling frequency multiplier is determined based on the defect level: if the defect level is medium, the sampling frequency is increased to twice the initial detection sampling frequency; if the defect level is severe, the sampling frequency is increased to four times the initial detection sampling frequency. After the verification is completed, the initial detection sampling frequency will be restored.

9. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 7, characterized in that, When determining the latest defect level based on the comparison results, the following steps are included: If the defect level determined based on the re-inspection data is consistent with the initial defect level, then the initial defect level will be the latest defect level. If the defect level determined based on the re-inspection data is inconsistent with the initial defect level, the defect level determined based on the re-inspection data will be the latest defect level.

10. The ultrasonic non-destructive testing device for high-speed rail safety monitoring according to claim 1, characterized in that, The ultrasonic non-destructive testing device for high-speed rail safety monitoring also includes a telescopic handle, which is fixed to one side of the support frame. The telescopic handle includes a telescopic rod and an anti-slip handrail. The bottom of the telescopic rod is fixed to the support frame, and the anti-slip handrail is fixed to the end of the telescopic rod away from the support frame.

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