Railway vehicle communication cable broken wire array eddy current detection probe, system and method

Abstract

The invention belongs to the technical field of eddy current detection. The rail vehicle communication cable broken wire array eddy current detection probe comprises a plane winding displacement coil and a differential three-dimensional coil array, the plane winding displacement coil is used for applying high-frequency excitation, and the differential three-dimensional coil array is used for sensing broken wire defect magnetic field disturbance; the differential three-dimensional coil array comprises a plurality of differential three-dimensional coil pairs, each differential three-dimensional coil pair comprises a first three-dimensional coil and a second three-dimensional coil, the first three-dimensional coil is arranged at the position where the magnetic field disturbance gradient of the planar winding displacement coil is maximum, and the second three-dimensional coil is arranged at the position where the magnetic field disturbance gradient of the planar winding displacement coil is minimum. The detection bottleneck of a thick insulating layer is broken through, the channel consistency of the array probe is optimized, the detection efficiency and precision of the communication cable under the large lift-off working condition are greatly improved, interference is effectively restrained, the structural adaptability is high, and effective recognition of the broken wire in the cable can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of eddy current testing, in particular to a rail vehicle communication cable broken wire array eddy current testing probe, system and method. BACKGROUND

[0002] The rail vehicle communication cable undertakes the core functions of efficient transmission of train group electric energy and interconnection of key electrical equipment, and the stability and long-term reliability of its signal and energy transmission are crucial to system operation. Under the continuous operation state of the train, the cable inside the cable bears significant periodic dynamic mechanical stress, mainly in the form of extrusion and friction wear. During the service period, such repeated stress can induce fatigue cumulative damage of the internal cable of the cable, eventually leading to cable fracture failure, which will directly cause the electrical performance degradation of the electrical connector (such as increased contact resistance and decreased current carrying capacity), and thus pose a potential threat to the stability of the rail vehicle traction power supply system and the operation safety of the whole vehicle.

[0003] Although the eddy current testing technology is widely used in defect identification of surfaces with conductive materials, it has great limitations in detecting internal broken wires of rail vehicle communication cables. The outer rubber insulation layer of the rail vehicle communication cable is relatively thick (generally greater than 5mm), and the induced magnetic field generated by the traditional eddy current testing method under large lift-off (i.e. the distance between the detection probe and the surface of the detected workpiece is large) conditions decays severely, making it difficult to effectively detect the internal copper broken wires. In addition, due to the uncertainty of the disturbance magnetic field diffusion caused by the lift-off, the channel consistency of the array probe detection is difficult to adjust, and the single-channel probe detection of a complete cable requires a long time, which seriously restricts the detection efficiency. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a rail vehicle communication cable broken wire array eddy current testing probe, system and method, which breaks through the detection bottleneck of thick insulation layer, optimizes the channel consistency of the array probe, greatly improves the detection efficiency and precision of the communication cable under large lift-off conditions, effectively suppresses interference, has strong structure adaptability, and can effectively identify the internal broken wires of the cable.

[0005] To achieve the above-mentioned purpose, the present application is realized by the following technical solutions: In a first aspect, the present application provides a rail vehicle communication cable broken wire array eddy current testing probe.

[0006] The rail vehicle communication cable broken wire array eddy current testing probe comprises a planar wire coil and a differential stereo coil array, the planar wire coil is used to apply high-frequency excitation, and the differential stereo coil array is used to induce broken wire defect magnetic field disturbance. The differential stereo coil array comprises a plurality of differential stereo coil pairs, each differential stereo coil pair comprising a first stereo coil and a second stereo coil, the first stereo coil being arranged at a position where the magnetic field disturbance gradient of the planar array coil is maximum, and the second stereo coil being arranged at a position where the magnetic field disturbance gradient of the planar array coil is minimum.

[0007] In an implementation form of the first aspect of the application, a ferrite core is arranged in each of the first stereo coil and the second stereo coil.

[0008] In an implementation form of the first aspect of the application, the planar array coil is a rectangular racetrack array coil arranged in multiple turns, and a central axis of the rectangular racetrack array coil is arranged at the position where the magnetic field disturbance gradient is minimum.

[0009] As a further limitation of the first aspect of the application, the long racetrack array coil region of the rectangular racetrack array coil is an effective region of the probe, and a plurality of differential stereo coil pairs are arranged at equal intervals in the effective region of the probe, each differential stereo coil pair independently outputting an induced result.

[0010] In an implementation form of the first aspect of the application, a flexible shell is further included, and the planar array coil and the differential stereo coil array are arranged in the flexible shell, and a wear-resistant bottom layer of the flexible shell is in the same shape as a surface curvature of the rail vehicle communication cable.

[0011] In an implementation form of the first aspect of the application, the planar array coil is printed on a flexible substrate.

[0012] In a second aspect, the application provides a rail vehicle communication cable broken wire array eddy current detection method.

[0013] A rail vehicle communication cable broken wire array eddy current detection method uses the rail vehicle communication cable broken wire array eddy current detection probe of the first aspect of the application, and comprises the following processes: The rail vehicle communication cable broken wire array eddy current detection probe is attached along a circumference of the rail vehicle communication cable, and is scanned at a uniform speed along an axial direction of the rail vehicle communication cable, and each differential stereo coil pair independently outputs; According to the output signal of each differential stereo coil pair, the degree and position of the broken wire are determined.

[0014] In an implementation form of the second aspect of the application, the output of each stereo coil is : , , , represents interference noise of the peak position of the magnetic field disturbance gradient, represents a defect disturbance signal, is a sensitive coefficient of local magnetic field disturbance of the coil pair at the central axis of the planar array coil, The correlation coefficient between the position noise of the center axis of the planar array coil and the peak value area noise of the magnetic field disturbance gradient.

[0015] In an implementation form of the second aspect of the present application, determining the broken wire position according to the output signals of each differential stereo coil pair comprises: The plurality of differential stereo coil pairs are sequentially scanned for broken wire positions, and when each differential stereo coil pair senses a broken wire at a certain position or the number of differential stereo coil pairs sensing a broken wire at a certain position is greater than a set threshold, it is determined that a broken wire exists at the position.

[0016] In an implementation form of the second aspect of the present application, determining the broken wire degree according to the output signals of each differential stereo coil pair comprises: The broken wire degree is divided according to the mean value of the output signals of all differential stereo coil pairs, or the broken wire degree is divided according to the maximum value of the output signals of all differential stereo coil pairs.

[0017] In a third aspect, the present application provides a rail vehicle communication cable broken wire array eddy current detection system, comprising the rail vehicle communication cable broken wire array eddy current detection probe of the first aspect of the present application.

[0018] The beneficial effects of the present application are as follows: The present application innovatively develops a rail vehicle communication cable broken wire array eddy current detection probe, which comprises a planar array coil and a differential stereo coil array. The planar array coil provides high-frequency excitation, and the differential stereo coil array is responsible for sensing the defect magnetic field disturbance. In each pair of differential stereo coils, one is located at the array coil with the maximum magnetic field disturbance gradient to sense local defects, and the other is located at the center axis with the minimum gradient to balance the eddy current field. An iron core is arranged in each coil, which can break through the detection bottleneck of thick insulation layer, optimize the consistency of the array probe channel, greatly improve the detection efficiency and accuracy, effectively suppress interference, and has strong structural adaptability, and can effectively identify the internal broken wire (broken wire degree and broken wire position) of the cable.

[0019] This invention innovatively proposes an eddy current detection method for broken wire arrays in rail vehicle communication cables. The output of the three-dimensional coil is set as the difference between the signal at the peak position of the magnetic field disturbance gradient and the signal at the central axis position of the planar coil. Simultaneously, by combining the sensitivity coefficient of the coil at the central axis to local magnetic field disturbances, the correlation coefficient between the noise at the central axis position and the noise in the peak region of the magnetic field disturbance gradient, the interference noise and defect disturbance signal at the peak position are separated. This yields the output result of the three-dimensional coil. This method solves the problems of defect disturbance signals being easily masked by interference noise and low signal identification in traditional eddy current detection. It overcomes the limitation of noise and effective signal aliasing in single-position signal detection, breaks through the difficulty of signal separation under thick insulation layers or complex working conditions, improves the extraction accuracy of defect disturbance signals, enhances the signal-to-noise ratio of the detected signal, and allows weak broken wire defect signals to be presented more clearly. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 A schematic diagram of the detection principle of a broken wire array eddy current detection probe for rail vehicle communication cables provided as an exemplary embodiment of the present invention; Figure 2 A finite element simulation of the local disturbance magnetic field gradient curve of a planar ribbon coil provided as an exemplary embodiment of the present invention; Figure 3 Provided as an exemplary embodiment of the present invention Figure 2 Internal structure diagram of the eddy current detection probe for broken wire array of rail vehicle communication cable, designed by finite element simulation of planar cabling. Figure 4 A schematic diagram of a broken wire array eddy current detection probe for rail vehicle communication cables provided as an exemplary embodiment of the present invention; Figure 5 A comparison diagram of channel consistency results when the array eddy current detection probe detects the same broken wire inside the cable, as an exemplary embodiment of the present invention. Detailed Implementation

[0022] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] The service environment of communication cables for rail vehicles is complex. They must withstand multiple influences such as vibration, friction, and temperature fluctuations during train operation. Moreover, the cable surface is mostly arc-shaped with uneven thickness of the outer insulation layer, making it difficult for traditional rigid probes to achieve a tight fit, resulting in severe signal attenuation. At the same time, the consistency of the multi-channel array probe directly affects the reliability of the detection results, while a single-channel design cannot meet the requirements for efficient scanning.

[0024] To address the shortcomings of existing solutions, this implementation proposes an eddy current detection probe for broken wires in rail vehicle communication cables based on planar cable excitation. Based on the principle of planar cable excitation combined with differential three-dimensional coil array reception, the distribution of the differential three-dimensional coil array is designed to achieve high detection efficiency for broken wires under large lifting conditions. Specifically, it consists of two parts: a planar cable coil and a differential three-dimensional coil array. The planar cable coil applies high-frequency excitation, while the differential three-dimensional coil array senses the magnetic field disturbance of the broken wire defect. For each pair of differential coils, one is located at the cable section with the largest magnetic field disturbance gradient in the planar cable coil, used to sense local magnetic field disturbances; the other is located at the central axis with the smallest magnetic field disturbance gradient, used to balance the eddy current field intensity. Ferrite cores are placed inside each three-dimensional coil to further improve the detection sensitivity of broken wire defects. This probe achieves high detection efficiency for rail vehicle communication cables under large lifting conditions. The specific detection principle is as follows: Figure 1 As shown, after excitation by planar cabling, the maximum and minimum disturbance gradients are generated respectively. The two work together on the differential vertical coil array to finally achieve multi-channel signal output.

[0025] More specifically, the planar ribbon coil in this implementation is a long strip raceway ribbon coil (including multi-turn rectangular coils), fabricated using flexible printed circuit board (FPCB) technology. This planar ribbon coil can effectively suppress the lift-off effect of eddy currents and generate a large-scale uniform eddy current field. The long raceway region of the rectangular raceway can form a large-scale uniform magnetic field region, providing a stable excitation magnetic field environment for the arrangement of differential three-dimensional coil arrays. The multi-turn arrangement can enhance the magnetic field strength, improve the magnetic field's penetration ability through thick insulating layers, and alleviate the problem of severe magnetic field attenuation under large lift-off conditions.

[0026] In the cable layout design, the coil line width, spacing, and number of turns are all optimized based on the principle of "balance between magnetic field uniformity and penetration": the selection of line width and spacing should avoid mutual inductance interference between adjacent coils, while ensuring that the overall resistance of the coil is within a reasonable range to avoid excessive energy loss under high-frequency excitation; the design of the number of turns takes into account the actual working conditions such as insulation layer thickness and detection distance, and seeks a balance between magnetic field strength and coil impedance to ensure that the excitation magnetic field can effectively penetrate the thick insulation layer and act on the metal wire inside the cable.

[0027] Optionally, the planar ribbon cable coil is printed on a flexible substrate. After the differential three-dimensional coil array is arranged, the flexible substrate is placed inside a flexible shell. The wear-resistant bottom layer of the flexible shell is tile-shaped with the same curvature as the cable surface to ensure the probe fits the cable.

[0028] In this implementation, the selection of the flexible substrate must meet multiple requirements: First, flexibility, which can adapt to the curved surface of the communication cable of the rail vehicle to achieve a tight fit between the probe and the cable; second, insulation, which prevents short circuits between the coil and the external structure and ensures stable transmission of the excitation signal; third, environmental resistance, which can withstand temperature changes (-40℃~85℃), vibration and slight friction during the operation of the rail vehicle to ensure long-term service stability; and fourth, dimensional stability, which is not easily deformed under temperature changes and mechanical stress to avoid coil parameter drift affecting detection accuracy.

[0029] In some other implementations, planar ribbon cable coils are printed on a flexible substrate, and after the differential three-dimensional coil array is arranged, the wear-resistant layer at the bottom of the flexible substrate is set to a tile shape with the same curvature as the cable surface; or, after the planar ribbon cable coils are printed on a flexible substrate, the planar ribbon cable coils and the differential three-dimensional coil array are arranged, and a flexible shell is used to seal the planar ribbon cable coils and the differential three-dimensional coil array. In this case, the flexible substrate directly serves as the base plate of the flexible shell, and the wear-resistant layer at the bottom of the flexible substrate is still set to a tile shape with the same curvature as the cable surface.

[0030] Optionally, when a flexible shell is present, the following assembly process can be used: The first step is flexible substrate pretreatment: Select a flexible substrate material that combines flexibility, insulation and temperature resistance, clean and level its surface to remove impurities and residual stress, ensure the accuracy and stability of subsequent coil printing, and avoid coil parameter drift caused by substrate deformation.

[0031] The second step is the fabrication and fixing of the planar ribbon coil: The planar ribbon coil is fabricated on the pre-treated flexible substrate using flexible printed circuit technology (FPCB) to ensure the regularity and spacing of the coil traces. After printing, a curing process is performed to enhance the bonding strength between the coil and the substrate. Then, the flexible substrate with the printed planar ribbon coil is laid flat in the preset mounting position inside the flexible shell and fixed with high-temperature resistant and vibration-resistant adhesive material to ensure that the coil does not shift under the vibration environment of train operation.

[0032] The third step is the assembly of the differential 3D coil array: Following the magnetic field disturbance gradient distribution determined by finite element simulation, the differential 3D coil pairs are positioned and installed within the effective area of ​​the planar coil array. The first and second coils of each differential 3D coil pair must strictly correspond to the preset maximum and minimum positions of the magnetic field disturbance gradient. During installation, high-precision positioning fixtures are used to ensure the spatial orientation consistency of the coils, avoiding signal differences between channels due to installation deviations. After assembly, the pins of each 3D coil are neatly arranged to ensure stable connection with the external signal processing module.

[0033] The fourth step is ferrite core embedding: A ferrite core of appropriate size is embedded in the internal cavity of each first and second three-dimensional coil. During the embedding process, it is ensured that the core is tightly fitted to the inner wall of the coil without any loose gaps, so as to give full play to the magnetic field focusing and enhancement effect of the ferrite core, improve the coil's sensitivity to magnetic field disturbances caused by broken wire defects, and suppress the attenuation of the magnetic field in the thick insulation layer.

[0034] Step 5, Flexible Housing Encapsulation: The flexible substrate equipped with the planar ribbon coil and differential 3D coil array is encapsulated inside the flexible housing. The wear-resistant bottom layer of the flexible housing is tightly attached to the flexible substrate to ensure the overall flexibility and structural integrity of the probe after encapsulation. During the encapsulation process, a signal transmission interface is reserved, and the interface is sealed to prevent dust, moisture and other impurities from entering, thereby improving the environmental adaptability of the probe.

[0035] In this implementation, a differential three-dimensional coil array is used to sense normal eddy current disturbances. The use of differential reception can improve the sensitivity of wire breakage detection while suppressing common-mode noise. In each pair of differential three-dimensional coils, one is located at the location of the coil with the largest magnetic field disturbance gradient to sense local magnetic field disturbances, and the other is located at the central axis location with the smallest magnetic field disturbance gradient to balance the eddy current field intensity. This receiver design can further reduce lift-off effect interference. In this implementation, the magnetic field disturbance gradient refers to the sensitivity to local disturbance magnetic field sensing. The magnetic field at the central axis of the coil in the long runway coil is only sensitive to overall changes, and its sensitivity to local disturbances is the weakest.

[0036] In this implementation, each three-dimensional coil is equipped with a ferrite core. The introduction of the ferrite core is a key design to improve detection sensitivity and break through the detection bottleneck of thick insulation layer. Ferrite material has the characteristics of high permeability, low coercivity and low loss. Its role is mainly reflected in the following three aspects: (1) Magnetic field focusing effect. The ferrite core can concentrate the dispersed magnetic field generated by the planar wire coil, so that the magnetic field energy is concentrated in the induction area of ​​the coil, enhance the magnetic field strength, improve the magnetic field penetration ability of the thick insulation layer, and ensure that the magnetic field can effectively reach the thick insulation layer under the large lifting condition. (1) The metal wire inside the cable induces eddy currents of sufficient strength; (2) Improve the sensing sensitivity. The converged magnetic field makes the magnetic field disturbance signal caused by the wire breakage defect more concentrated. The three-dimensional coil can capture the disturbance signal more accurately, greatly improve the amplitude of the defect signal, and enable the weak wire breakage defect signal to be effectively separated from the background noise, thereby improving the detection capability of minor wire breakage, local wire breakage and other defects; (3) Suppress magnetic field diffusion: The ferrite core can limit the diffusion range of the magnetic field, reduce the magnetic field interference between adjacent coil pairs, and optimize the channel consistency of the array probe. At the same time, the suppression of magnetic field diffusion can also reduce the interference of the external environment on the detection magnetic field and improve the anti-interference capability of the probe.

[0037] In this implementation, for a single three-dimensional differential coil pair, it is assumed that the interference noise at the peak position of the magnetic field disturbance gradient is... The defect disturbance signal is ,but: (1); (2); (3); In the formula, The output of the three-dimensional coil is for the peak region of the magnetic field disturbance gradient. To output a three-dimensional coil at the central axis position, The output is the difference between the two. This is the sensitivity coefficient of the coil at the central axis to local magnetic field disturbances. The correlation coefficient between the noise at the center axis position and the noise in the peak region of the magnetic field disturbance gradient; In this implementation, the long track area of ​​the rectangular cable arrangement serves as the effective area of ​​the probe. Within this area, the magnetic field distribution is uniform. To achieve comprehensive cable coverage scanning, multiple differential 3D coil pairs are arranged at equal intervals within the effective area. The core advantages of this equal-interval arrangement are: firstly, it ensures no blind spots during scanning, as the detection range of each coil pair is interconnected, covering the entire cable surface; secondly, it helps ensure the consistency of multi-channel signals, as the uniform spacing ensures that the magnetic field environment of each coil pair is essentially the same, reducing channel differences caused by uneven magnetic field distribution; and thirdly, it facilitates subsequent signal processing and location positioning, as the equal-interval layout allows the location of broken wire defects to be quickly calculated using the coil pair number and scanning speed.

[0038] Each differential 3D coil pair outputs an independent sensing signal. This independent output design enables multi-channel parallel detection, significantly improving detection efficiency. Compared to traditional single-channel probes that need to scan the entire cable point by point, the array design of this invention can simultaneously detect multiple areas of the cable. The detection efficiency is positively correlated with the number of coil pairs, and the number of coil pairs can be flexibly adjusted according to actual detection needs, balancing detection efficiency and equipment cost.

[0039] like Figure 2 , Figure 3 The figures show the local disturbance magnetic field gradient curve of the planar coil in finite element simulation and the internal structure of the eddy current detection probe for broken wire array of rail vehicle communication cable designed based on the simulation. A differential three-dimensional coil receiving array is constructed according to the number of coil turns and the corresponding magnetic field disturbance gradient distribution in the finite element simulation.

[0040] like Figure 4 The diagram shows a schematic of an eddy current detection probe for broken wire arrays in rail vehicle communication cables based on wire excitation. The detection target is the outermost layer of cable near the rubber insulation layer. This layer of cable consists of 30 small strands of cable spirally wound together, each strand with a diameter of 3.5 mm, and the rubber insulation layer is 7 mm thick. During scanning, the probe is placed circumferentially along the cable and scans at a uniform speed axially. Each receiving differential 3D coil pair outputs independently. By analyzing the output signal of each differential 3D coil pair, the degree and location of the broken wire can be determined.

[0041] In this implementation, the scanning speed must be kept constant to avoid speed fluctuations that could lead to inconsistent signal acquisition time intervals and affect the positioning accuracy of the broken wire location. The selection of the scanning speed needs to comprehensively consider detection efficiency and signal resolution. Too fast a speed may result in insufficient signal acquisition and the omission of minor broken wire defects; too slow a speed will reduce detection efficiency and increase detection costs. In practical applications, the scanning speed can be flexibly adjusted according to the cable length and detection accuracy requirements, but it is necessary to ensure that the speed remains consistent throughout the same detection task. During the scanning process, it is necessary to ensure that the scanning path of the probe is parallel to the cable axis to avoid path deviation that could lead to overlapping or omission of detection areas. This can be achieved by marking guide lines on the cable surface or using auxiliary guiding devices to ensure the straightness of the scanning path. During the scanning process, it is necessary to avoid strong magnetic fields, strong electric fields, and other interference sources near the probe, as strong interference sources can cause distortion of the excitation magnetic field and induction signal, affecting the detection results. At the same time, it is necessary to maintain stable temperature and humidity in the detection environment to avoid extreme environmental conditions that could cause fluctuations in probe performance.

[0042] In this implementation, each differential three-dimensional coil pair outputs an independent induction signal. The signal acquisition module needs to establish an independent signal transmission channel with each coil pair to ensure that the signal transmission delay of each channel is consistent. Synchronous acquisition technology is adopted, and the acquisition time of all channels is controlled by a unified clock signal to ensure that the signals of each coil pair can be acquired synchronously at the same time, avoiding the deviation in the location of the broken wire due to the acquisition time difference. The sampling frequency needs to be determined according to the frequency of the high-frequency excitation signal and the characteristic frequency of the broken wire defect to ensure that the sampling frequency satisfies the Nyquist sampling theorem, can completely capture the waveform characteristics of the defect signal, and avoid signal aliasing that leads to information loss. During the sampling process, the signal needs to be filtered in real time to initially remove high-frequency noise and improve signal quality.

[0043] In this implementation, the determination of the wire breakage location is based on the collaborative analysis of multi-channel signals, and the specific rules are as follows: Multiple differential 3D coil pairs sequentially scan the area to be inspected along the cable axis. Each coil pair outputs a differential signal in real time during the scanning process. When a broken wire defect exists at a certain location, that location will be sequentially scanned and covered by multiple coil pairs. Each coil pair will sense the magnetic field disturbance caused by the defect and output the corresponding defect signal.

[0044] The judgment logic is divided into two cases: First, when all differential 3D coil pairs sense a defect signal at a certain location, it is determined that there is a broken wire at that location. This judgment method has an extremely low false detection rate and is suitable for scenarios with extremely high detection accuracy requirements. Second, when the number of coil pairs that sense a defect signal at a certain location is greater than a set threshold, it is determined that there is a broken wire at that location. The threshold setting needs to be adjusted according to the false detection rate and false negative rate requirements of the actual application scenario. For example, in a rapid screening scenario, the threshold can be appropriately lowered to improve detection efficiency; in a precision detection scenario, the threshold can be increased to ensure detection accuracy.

[0045] In addition, the specific coordinates of the broken wire location are calculated as follows: based on the scanning speed and signal acquisition time, combined with the arrangement spacing of the coil pairs, the time point at which each coil pair senses the defect signal is determined, and the axial position of the defect is calculated by the time difference and scanning speed; combined with the circumferential arrangement position of the coil pairs, the circumferential position of the defect is determined, and finally the precise location of the broken wire location is achieved.

[0046] In this implementation, the degree of wire breakage is determined based on the amplitude characteristics of the differential signal. The core logic is that the amplitude of the defect signal is positively correlated with the degree of wire breakage: the more wires broken and the larger the area of ​​wire breakage, the more severe the magnetic field disturbance, and the larger the amplitude of the differential signal. The specific determination method is as follows: Method 1: Classify based on the average output signal of all differential 3D coil pairs. Calculate the average output signal of all coil pairs that sensed the defect, and compare the average with a preset severity grading threshold to classify into levels such as minor wire breakage, moderate wire breakage, and severe wire breakage. This average-based classification method comprehensively reflects the overall situation of the wire breakage defect, avoiding misjudgments caused by signal fluctuations from a single coil pair.

[0047] Method 2: Classify based on the maximum value of the output signal from all differential 3D coil pairs. Select the maximum value of the output signal from all coil pairs that sensed the defect, and compare the maximum value with a preset severity grading threshold to determine the degree of wire breakage. This maximum value classification method highlights the characteristics of the most severely broken area and is suitable for detection scenarios sensitive to locally severe wire breakage.

[0048] The setting of severity grading thresholds must be based on extensive experimental data and practical application experience, combined with cable usage requirements and maintenance standards, to clearly define the signal amplitude range corresponding to different degrees of wire breakage, ensuring that the grading results can provide a valid basis for cable maintenance decisions. For example, minor wire breakage corresponds to a small signal amplitude, and regular monitoring can be recommended; moderate wire breakage corresponds to a medium signal amplitude, and timely maintenance should be arranged; severe wire breakage corresponds to a large signal amplitude, and the cable should be immediately shut down and replaced to avoid safety accidents.

[0049] Figure 5 This image shows a comparison of channel consistency results when an array eddy current detection probe detects the same broken wire inside a cable. It can be seen that the probe can detect the magnetic field disturbance of the broken wire, and the signal consistency is good when different differential 3D coils scan the same broken wire defect, meeting the requirements of an array probe.

[0050] Alternatively, in some other implementations, the specifications (such as diameter and insulation thickness) of the communication cable for rail vehicles differ from the service conditions (such as ambient temperature and vibration intensity). Targeted optimization design is required to ensure that the probe and detection method can be adapted to different conditions and to ensure the stability of the detection performance.

[0051] For cable insulation layers of varying thicknesses (commonly greater than 5mm), adaptation can be achieved through the following methods: Adjust the high-frequency excitation frequency of the planar ribbon cable coil according to the insulation layer thickness. For thicker insulation layers, appropriately reduce the excitation frequency to increase the magnetic field penetration depth, ensuring the magnetic field effectively reaches the internal metal cable; for thinner insulation layers, appropriately increase the excitation frequency to improve detection sensitivity and capture minor wire breakage defects. For different insulation layer thicknesses, select ferrite cores with different permeability. For thicker insulation layers, use high-permeability cores to enhance magnetic field focusing and penetration; for thinner insulation layers, use medium-permeability cores to ensure detection sensitivity while avoiding signal saturation caused by excessively strong magnetic fields.

[0052] For communication cables of different diameters in rail vehicles, a flexible structural design can achieve adaptability: the wear-resistant bottom layer of the flexible shell and the overall structure have good flexibility, and can elastically deform according to the cable diameter to ensure a tight fit with cables of different diameters; for cables with large diameter differences, the fit can be further improved by replacing the wear-resistant bottom layer module with different curvature specifications, and the compatibility range covers the diameter specifications of common rail vehicle communication cables; for small diameter cables, a bundling fixing method can be used to tightly bind the probe to the cable surface for scanning; for large diameter cables, magnetic or snap-on fixing methods can be used to ensure the stability of the probe during the scanning process and avoid the probe from loosening due to the large cable diameter.

[0053] Rail vehicles operate under complex conditions including vibration, temperature fluctuations, and electromagnetic interference. The following design features can enhance anti-interference capabilities: the coil module inside the probe is elastically fixed, and the flexible shell is made of flexible material, capable of absorbing vibration energy and reducing the impact of vibration on the coil's position and electrical performance; simultaneously, the coil pins use flexible connections to prevent pin breakage or poor contact due to vibration; materials with excellent temperature resistance are selected for the coil, substrate, and flexible shell to ensure stable probe performance parameters without significant drift within a temperature range of -40℃ to 85℃; high-temperature resistant wires are used for the coil conductors to prevent short circuits caused by insulation aging under high-temperature environments; the wiring of the planar ribbon coil and differential 3D coil array employs a shielded design to reduce the impact of external electromagnetic interference on the signal; shielded cables are used for signal transmission lines to further suppress electromagnetic interference; and digital filtering algorithms are used during signal processing to remove noise signals caused by electromagnetic interference.

[0054] This implementation also proposes a broken wire array eddy current detection system for rail vehicle communication cables, including the probe described above, as well as a signal generator module, a power amplifier module, a signal acquisition module, a signal processing module, and a display and storage module.

[0055] The signal generator module is used to generate high-frequency excitation signals to provide an excitation source for the planar ribbon coil. The frequency and amplitude of the excitation signal can be flexibly adjusted according to the detection conditions.

[0056] The power amplifier module amplifies the high-frequency excitation signal generated by the signal generator to ensure that the excitation signal can drive the planar ribbon coil to generate a magnetic field of sufficient strength.

[0057] The signal acquisition module is used to connect with the differential three-dimensional coil array of the probe, synchronously acquire the output signals of each coil pair, convert the analog signals into digital signals, and transmit them to the signal processing module.

[0058] The signal processing module uses an embedded processor or computer to run signal processing algorithms and perform differential calculations, filtering, feature extraction, and determination of the location and degree of wire breakage on the acquired digital signals.

[0059] The display and storage module is used to display the judgment results (fracture location, degree of fracture, detection time, etc.) of the signal processing module in real time in the form of graphics and text, and at the same time store the detection data and signal waveforms for easy subsequent query, analysis and traceability.

[0060] After the system starts up, the modules work together according to the following process: The first step is parameter setting: set the detection parameters through the display module, including high-frequency excitation frequency, scanning speed, filament breakage grading threshold, and position determination threshold; The second step is the generation and amplification of the excitation signal: the signal generator module generates a high-frequency excitation signal according to the set parameters, which is then amplified by the power amplifier module and input to the planar ribbon coil of the probe. The third step is the generation and induction of magnetic field: Under the action of a high-frequency excitation signal, the planar coil generates an alternating magnetic field. The magnetic field penetrates the cable insulation layer and induces eddy currents in the internal metal wire. If there is a broken wire defect, the eddy current distortion will cause magnetic field disturbance, and the differential three-dimensional coil array should induce the disturbance signal. The fourth step is signal acquisition and conversion: the signal acquisition module synchronously acquires the induced signals of each coil pair, converts the analog signals into digital signals, and transmits them to the signal processing module; The fifth step is signal processing and judgment: the signal processing module performs differential calculation, filtering, and feature extraction on the digital signal, and determines the location and extent of the wire breakage based on a preset threshold. Step 6, Result Display and Storage: The display module displays the judgment results such as the location and degree of wire breakage in real time, and the storage module stores the detection data and signal waveforms, completing one detection process.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An eddy current detection probe for broken wire arrays in rail vehicle communication cables. Its features are, Includes: a planar ribbon coil and a differential three-dimensional coil array, wherein the planar ribbon coil is used to apply high-frequency excitation, and the differential three-dimensional coil array is used to sense magnetic field disturbances caused by wire breakage defects; The differential three-dimensional coil array includes multiple differential three-dimensional coil pairs. Each differential three-dimensional coil pair includes a first three-dimensional coil and a second three-dimensional coil. The first three-dimensional coil is arranged at the position where the magnetic field disturbance gradient of the planar ribbon coil is the largest, and the second three-dimensional coil is arranged at the position where the magnetic field disturbance gradient of the planar ribbon coil is the smallest.

2. The eddy current detection probe for broken wire arrays in rail vehicle communication cables as described in claim 1, characterized in that, Both the first and second three-dimensional coils are equipped with ferrite cores.

3. The eddy current detection probe for broken wire arrays in rail vehicle communication cables as described in claim 1, characterized in that, The planar coil is a rectangular track coil with multiple turns, and the central axis of the rectangular track coil is located at the position of minimum magnetic field disturbance gradient.

4. The eddy current detection probe for broken wire arrays in rail vehicle communication cables as described in claim 3, characterized in that, The long track layout area of ​​the rectangular track layout is the effective area of ​​the probe. Multiple differential three-dimensional coil pairs are arranged at equal intervals within the effective area of ​​the probe, and each differential three-dimensional coil pair independently outputs the sensing result.

5. The eddy current detection probe for broken wire arrays in rail vehicle communication cables as described in any one of claims 1-4, characterized in that, The planar ribbon cable coil is printed and arranged on a flexible substrate; Alternatively, both the planar ribbon coil and the differential three-dimensional coil array are arranged within a flexible housing, wherein the wear-resistant bottom layer of the flexible housing has the same shape as the surface curvature of the rail vehicle communication cable.

6. A method for detecting eddy current array breaks in communication cables for rail vehicles, characterized in that, Using the eddy current detection probe for broken wire arrays in rail vehicle communication cables as described in any one of claims 1-5, The process includes the following: The broken wire array eddy current detection probe of the rail vehicle communication cable is attached to the circumference of the rail vehicle communication cable and scans at a constant speed along the axial direction of the rail vehicle communication cable. Each differential three-dimensional coil pair outputs independently. The degree and location of wire breakage are determined based on the output signal of each differential three-dimensional coil pair.

7. The eddy current detection method for broken wire arrays in rail vehicle communication cables as described in claim 6, characterized in that, The output of each of the three-dimensional coils for: ,in, , , The interference noise representing the peak location of the magnetic field disturbance gradient. This represents a defect disturbance signal. This is the sensitivity coefficient of the coil at the central axis of the planar ribbon coil to local magnetic field disturbances. This is the correlation coefficient between the noise at the center axis position of the planar ribbon coil and the noise in the peak region of the magnetic field disturbance gradient.

8. The eddy current detection method for broken wire arrays in rail vehicle communication cables as described in claim 6, characterized in that, Determining the location of the broken wire based on the output signal of each differential three-dimensional coil pair includes: Multiple differential three-dimensional coils sequentially scan the broken wire location. When each differential three-dimensional coil pair senses a broken wire at a certain location, or when the number of differential three-dimensional coil pairs that sense a broken wire at a certain location is greater than a set threshold, it is determined that a broken wire exists at this location.

9. The eddy current detection method for broken wire arrays in rail vehicle communication cables as described in claim 6, characterized in that, The degree of wire breakage is determined based on the output signal of each differential three-dimensional coil pair, including: The degree of wire breakage is classified according to the average value of the output signals of all the differential three-dimensional coil pairs; or, the degree of wire breakage is classified according to the maximum value of the output signals of all the differential three-dimensional coil pairs.

10. A broken wire array eddy current detection system for railway vehicle communication cables, characterized in that, Including the eddy current detection probe for broken wire array of rail vehicle communication cable as described in any one of claims 1-5.

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