Method, device and equipment for detecting track

Abstract

The invention provides a method, device and equipment for detecting a track, and relates to the technical field of electromagnetic measurement. The method comprises the following steps: collecting measurement data of a track surface through a multi-channel eddy current sensor array; carrying out interpolation processing on the amplitude data of the collected measurement data so as to obtain the distribution of the amplitude of the measurement data along a first direction; the first direction is parallel to the top surface of the track, and the first direction is perpendicular to the extending direction of the track; determining a coordinate corresponding to an extreme value of the amplitude of the measurement data distributed along the first direction; the transverse center position of the track is determined according to the coordinates corresponding to the extreme value; wherein the position of the transverse center of the track is the center position of the track in the first direction. According to the method for detecting the track, the high-precision transverse center position can be obtained, and reliable standard information is provided for transverse alignment of the detected object and the sensor.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic measurement technology, and in particular to a method, device and equipment for detecting tracks. Background Art

[0002] In modern society, tracks play a vital role in the safety and reliability of railway operations, so non-destructive testing and scanning testing of tracks are required.

[0003] In the prior art, in order to reduce wear of the detection equipment during operation, in the absence of a physical connection between the rail and the detection probe, this detection requires ensuring that the detection probe is correctly aligned with the rail.

[0004] Therefore, it is crucial to ensure that the detection probe is correctly aligned with the rail so that rail defects can be detected accurately and timely. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the first aspect of the present application provides a method for detecting a track, the method comprising:

[0006] Collecting measurement data on the track surface through a multi-channel eddy current sensor array;

[0007] Performing interpolation processing on the amplitude data of the collected measurement data to obtain a distribution of the amplitude of the measurement data along a first direction; the first direction is parallel to the top surface of the track and perpendicular to the extension direction of the track;

[0008] determining coordinates corresponding to extreme values ​​of the distribution of the amplitude of the measurement data along the first direction;

[0009] The transverse center position of the track is determined according to the coordinates corresponding to the extreme values; wherein the transverse center position of the track is the center position of the track in the first direction.

[0010] Optionally, determining the transverse center position of the track according to the coordinates corresponding to the extreme value includes:

[0011] The transverse center position of the track is determined according to the deviation between the coordinate corresponding to the extreme value and the center of the multi-channel eddy current sensor array, where the deviation is the position deviation between the center of the multi-channel eddy current sensor array and the transverse center of the track.

[0012] Optionally, the measurement data includes one or more of an induced voltage, an inductance signal, or an impedance signal; or, the measurement data includes one or more of a phase of a signal or a mismatch amount of a multi-channel sensor array.

[0013] Optionally, measurement data collected from the track surface by a multi-channel eddy current sensor array includes:

[0014] Determine the layout and parameters of the multi-channel eddy current sensor array based on the track size;

[0015] energizing at least one coil in the multi-channel eddy current sensor array;

[0016] An electromagnetic response signal is received by at least one adjacent coil of the at least one coil.

[0017] Optionally, exciting at least one coil in the multi-channel eddy current sensor array includes: numbering all the coils in sequence, and exciting the coils in turn in the order of the numbers.

[0018] Optionally, receiving the electromagnetic response signal through at least one adjacent coil of the at least one coil includes:

[0019] Any two adjacent coils form a coil pair;

[0020] Collect the amplitude data of the measurement data of any set of coil pairs.

[0021] Optionally, the measurement data meets the following requirements:

[0022]

[0023] Among them, I e is the current amplitude applied to the excitation coil, Ω is the surface of the measurement space, and E T 、E R is the electric field strength generated by the excitation coil and the receiving coil, Δσ is the conductivity of the track, j is the imaginary unit, ω is the excitation frequency, H T 、H R is the magnetic field strength generated by the excitation coil and the receiving coil, Δμ is the magnetic permeability of the track, and dV is the volume element.

[0024] Optionally, performing interpolation processing on the amplitude data of the collected measurement data includes:

[0025] interpolating the real signal of the measurement data; and / or

[0026] Perform interpolation processing on the imaginary signal of the measurement data.

[0027] Optionally, after determining the horizontal center position of the track according to the coordinates corresponding to the extreme value, the method further includes:

[0028] The lift-off height of the multi-channel eddy current sensor array is changed, and the actual value of the lateral center position of the track is determined according to the different lift-off heights.

[0029] Optionally, after determining the transverse center position of the track according to the coordinates corresponding to the extreme values, the method further includes:

[0030] The multi-channel eddy current sensor array is controlled to perform real-time offset and feedback by generating a control signal in real time until the multi-channel eddy current sensor array is located at the lateral center of the track.

[0031] Optionally, determining the coordinates corresponding to the extreme value of the distribution of the amplitude of the measurement data along the first direction includes:

[0032] The coordinates corresponding to the extreme values ​​of the distribution of the amplitude of the real signal of the measurement data along the first direction are determined.

[0033] Optionally, determining the coordinates corresponding to the extreme value of the distribution of the amplitude of the measurement data along the first direction includes:

[0034] The local weighted regression filter is used to make the interpolated measurement data have a unique extreme value, and the coordinates corresponding to the unique extreme value are determined.

[0035] Optionally, the multi-channel eddy current sensor array includes a first row of coils and a second row of coils arranged in parallel in the second direction; the first row of coils and the second row of coils respectively include a plurality of coils arranged along the first direction; and the three coils in the multi-channel eddy current sensor array that are closest to each other along the second direction are distributed in an equilateral triangle; in a plane perpendicular to the top surface of the track, the second direction is perpendicular to the first direction.

[0036] A second aspect of the present application provides a device for track centering, for detecting the center of the track according to the method provided in the first aspect of the present application, the device comprising:

[0037] A multi-channel eddy current sensor array for collecting measurement data from the track surface;

[0038] a preprocessing module, configured to perform interpolation processing on the amplitude data of the collected measurement data, thereby obtaining a distribution of the amplitude of the measurement data along a first direction;

[0039] an analysis module, configured to determine coordinates corresponding to extreme values ​​of the distribution of the amplitude of the measurement data along the first direction;

[0040] The calculation module is used to determine the horizontal center position of the track according to the coordinates corresponding to the extreme values.

[0041] Optionally, the calculation module is used to:

[0042] The transverse center position of the track is determined according to the deviation between the coordinate corresponding to the extreme value and the center of the multi-channel eddy current sensor array, where the deviation is the position deviation between the center of the multi-channel eddy current sensor array and the transverse center of the track.

[0043] Optionally, the measurement data includes one or more of an induced voltage, an inductance signal, or an impedance signal; or, the measurement data includes one or more of a phase of a signal or a mismatch amount of a multi-channel sensor array.

[0044] Optionally, the multi-channel eddy current sensor array is specifically used for:

[0045] Determine the layout and parameters of the multi-channel eddy current sensor array based on the track size;

[0046] energizing at least one coil in the multi-channel eddy current sensor array;

[0047] An electromagnetic response signal is received by at least one adjacent coil of the at least one coil.

[0048] Optionally, the multi-channel eddy current sensor array is further specifically used for:

[0049] All coils are numbered in sequence and the coils are excited in turn in the order of their numbers.

[0050] Optionally, the multi-channel eddy current sensor array is further specifically used for:

[0051] Any two adjacent coils form a coil pair;

[0052] Collect the amplitude data of the measurement data of any set of coil pairs.

[0053] Optionally, the measurement data meets the following requirements:

[0054]

[0055] Among them, I e is the current amplitude applied to the excitation coil, Ω is the surface of the measurement space, and E T 、E R is the electric field strength generated by the excitation coil and the receiving coil, Δσ is the conductivity of the track, j is the imaginary unit, ω is the excitation frequency, H T 、H R is the magnetic field strength generated by the excitation coil and the receiving coil, Δμ is the magnetic permeability of the track, and dV is the volume element.

[0056] Optionally, the preprocessing module is specifically used to:

[0057] interpolating the real signal of the measurement data; and / or

[0058] Perform interpolation processing on the imaginary signal of the measurement data.

[0059] Optionally, the device further includes a processing module for changing the lift-off height of the multi-channel eddy current sensor array and determining the actual value of the lateral center position of the track according to different lift-off heights.

[0060] Optionally, the processing module is further configured to:

[0061] The multi-channel eddy current sensor array is controlled to perform real-time offset and feedback by generating a control signal in real time until the multi-channel eddy current sensor array is located at the lateral center of the track.

[0062] Optionally, the analysis module is specifically used to:

[0063] The coordinates corresponding to the extreme values ​​of the distribution of the amplitude of the real signal of the measurement data along the first direction are determined.

[0064] Optionally, the analysis module is further configured to:

[0065] The local weighted regression filter is used to make the interpolated measurement data have a unique extreme value, and the coordinates corresponding to the unique extreme value are determined.

[0066] Optionally, the multi-channel eddy current sensor array includes a first row of coils and a second row of coils arranged in parallel in the second direction; the first row of coils and the second row of coils respectively include a plurality of coils arranged along the first direction; and the three coils in the multi-channel eddy current sensor array that are closest to each other along the second direction are distributed in an equilateral triangle; in a plane perpendicular to the top surface of the track, the second direction is perpendicular to the first direction.

[0067] A third aspect of the present application provides a device for track centering, the device comprising:

[0068] A second aspect of the present application provides a device for detecting a track, for detecting a deviation between a track center and a center of a multi-channel eddy current sensor array;

[0069] The actuating mechanism is used for controlling the multi-channel eddy current sensor array to move in a first direction according to the deviation, so that the center of the multi-channel eddy current sensor array is aligned with the center of the track.

[0070] The beneficial effects that this application can achieve are:

[0071] The present application provides a sensor lateral alignment detection method that can collect measurement data from a sensor coil array through a multi-channel eddy current system, and uses interpolation and other curve drawing methods to obtain a smooth measurement curve, and obtains the lateral center position of the rail based on the coordinates corresponding to the extreme values ​​of the curve. The estimated value of the lateral center position obtained by the above method is close to the actual value, and the error of the estimated value is small, which improves the measurement accuracy and provides reliable standard information for the lateral alignment of the rail and the sensor. In addition, the sensor coil array in the present application increases the lateral length, increases the lateral coverage range of the rail, and improves the efficiency of detecting the lateral center position of the rail. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 A flow chart of a method for detecting a track provided in an embodiment of the present application;

[0073] Figure 2 A schematic diagram of an optional coil structure provided in an embodiment of the present application;

[0074] Figure 3 A schematic diagram of an optional arrangement of multiple coils and a schematic diagram of a measurement sequence provided in an embodiment of the present application;

[0075] Figure 4 A schematic diagram of the magnetic field range that can be generated by each of the multiple coils provided in an optional embodiment of the present application;

[0076] Figure 5 A schematic diagram of lateral alignment detection between a track and a multi-channel eddy current sensor array provided in an embodiment of the present application;

[0077] Figure 6 A schematic diagram of interpolation results of real induced voltage measured by a multi-channel eddy current sensor array provided in an embodiment of the present application;

[0078] Figure 7 A schematic diagram of a curve formed by the real voltage measurement value of each coil provided in an optional embodiment of the present application;

[0079] Figure 8 A schematic diagram of a curve formed by an optional imaginary voltage measurement value of each coil provided in an embodiment of the present application;

[0080] Figure 9 A schematic diagram of a filtered curve of an optional real voltage measurement value of each coil provided in an embodiment of the present application;

[0081] Figure 10 A graph showing comparison results of the actual lateral center position of the track and the estimated lateral center position of the track when the center position of the multi-channel eddy current sensor array provided in an embodiment of the present application is at different lift-off heights;

[0082] Figure 11 Schematic diagram of the lateral center position estimation error of the track when the center position of the multi-channel eddy current sensor array provided in an embodiment of the present application is at different lift-off heights.

[0083] Reference numerals:

[0084] 1: Magnetic core; 2: Coil; 3: Distance between the lateral center position of the track and the center position of the multi-channel eddy current sensor array; 4: Multi-channel eddy current sensor array; 5: Lift-off height of the multi-channel eddy current sensor array; 6: Track. DETAILED DESCRIPTION

[0085] In order to help those skilled in the art better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0086] In the embodiment of the present application, based on the horizontal plane of the top of the track, the first direction is the direction perpendicular to the extension of the track, and the second direction is the direction in which the track extends. Therefore, the horizontal center position of the track is the center position of the track in the first direction.

[0087] To address the issues presented in the background art, existing technologies have addressed track centering issues through structural alignment systems. These typically employ laser ranging, visual recognition, or track edge tracking to ensure that the detection platform can move along the track centerline, thereby achieving track centering. However, while these alignment methods can achieve track centering, they are unable to adapt to complex road conditions and, when the track is obstructed, are unable to perform real-time correction of track centering errors.

[0088] In addition to the aforementioned methods of using structural alignment systems to achieve track alignment, flaw detection systems can also be used. For example, devices using ultrasonic, eddy current, or electromagnetic acoustic transducer (EMAT) principles focus on detecting internal defects in the track. Specifically, current eddy current measurement typically uses a single pair of coils to detect the track's lateral center. Using a single set of coils, the track is directly inspected by excitation and reception signals. Single-pair eddy current testing devices are characterized by simple structure and low cost. Alternatively, the differential signal from two pairs of coils is used to detect the track's lateral center. The two pairs of independent coils are arranged symmetrically, and the reference and detection signals output by the two pairs of coils are differentiated by a differential amplifier circuit, thereby achieving track inspection. However, whether using a single or two-pair eddy current testing device, the coils are typically large and have limited coverage due to the limited number of coils. This results in low spatial resolution of the measurement signal, hindering accurate track inspection and requiring mobile sensing. Furthermore, the high coil resistance requires high drive power and energy consumption. In addition, the above-mentioned flaw detection equipment usually has problems such as probe offset, coupling anomaly, and detection blind spots due to insufficient centering accuracy.

[0089] In summary, it is obvious that the existing technology is currently unable to achieve unified coordination of precise alignment and high-sensitivity flaw detection under the same control system. It can only achieve independent detection of track alignment and flaw detection, which increases the cost of track alignment and flaw detection and the complexity of equipment, and reduces the efficiency of track alignment and flaw detection.

[0090] Based on this, the inventors discovered that eddy current measurements can be performed using small coils. Small coils have a smaller sensitive area, resulting in higher spatial resolution of the measurement signal, thus improving the accuracy of eddy current measurements. As coil size decreases, its coverage area also decreases. This can be achieved by increasing the number of small coils to ensure coverage of the track's transverse center. Furthermore, the reduced coil size reduces the overall coil resistance, thereby reducing the energy consumption required for eddy current measurement.

[0091] This embodiment of the application utilizes a high-speed electromagnetic measurement system to acquire measurement data from a small coil array sensitive to changes in the track center position. The track center is estimated based on the extreme values ​​of the measurement data curve. Furthermore, within the sensitive area of ​​the small coil array, single-frame measurements can accurately locate the track center at various probe liftoff heights, enabling both track inspection and calibration as well as defect detection.

[0092] Therefore, the embodiment of the present application provides a method for track centering, which aims to determine the transverse center position of the track based on eddy current technology so as to facilitate subsequent flaw detection and other inspections of the track. Figure 1 As shown, the above method includes the steps of:

[0093] S1. Collect measurement data of the track surface through a multi-channel eddy current sensor array.

[0094] A multi-channel eddy current sensor array is a highly efficient nondestructive testing device based on eddy current testing technology. By using multiple independent sensor channels operating simultaneously or in a time-sharing manner, it can achieve rapid and high-precision detection of surface and near-surface defects, electrical conductivity, magnetic permeability, and other parameters. The multi-channel eddy current sensor array includes a multi-channel probe composed of multiple independent coils, a signal processing system, and an imaging system. It can accurately detect the lateral center position of the object being tested and, in turn, detect surface or deep-seated defects. The multi-channel probe generates an electromagnetic response signal by induction between the multiple independent coils within it and the track.

[0095] In an embodiment of the present application, a multi-channel eddy current sensor array adopts an integrated installation of a centering system, a flaw detection system, and a track tracking system, thereby avoiding a decrease in detection repeatability due to the superposition of errors caused by the offset of each module or the individual centering of each module.

[0096] Figure 2This is an optional structural diagram of the coil provided in the embodiment of the present application. Figure 2 As shown, a magnetic core 1 is provided inside the coil 2, and the magnetic core 1 is arranged along the central axis of the coil 2. The coil is a core component in the eddy current detection equipment and can directly affect the magnetic field distribution, energy conversion efficiency and detection sensitivity.

[0097] In some embodiments, step S1 may specifically be collecting measurement data of the track surface in real time through a multi-channel eddy current sensor array.

[0098] In some embodiments, step S1 specifically includes:

[0099] Determine the layout and parameters of the multi-channel eddy current sensor array based on the track size;

[0100] energizing at least one coil in the multi-channel eddy current sensor array;

[0101] An electromagnetic response signal is received by at least one adjacent coil of the at least one coil.

[0102] In the above embodiment, the layout and parameters of the multi-channel eddy current sensor array need to be determined based on the track size. For example, the size of the track in the first direction is determined to determine the number of coils 2 arranged along the first direction in the multi-channel eddy current sensor array, as well as parameters such as the size of each coil 2 and the spacing between adjacent coils. This allows the multi-channel eddy current sensor array to cover the transverse center position of the track, thereby completing the measurement of the transverse center position of the track.

[0103] After determining the relative position between the track and the multi-channel eddy current sensor array, at least one coil in the multi-channel eddy current sensor array is excited, and the electromagnetic response signal is received by at least one adjacent coil of the at least one coil, and the at least one adjacent coil of the at least one coil is the receiving coil. For example, see Figure 3 , when coil d is the excitation coil, at least one of coils b, c, e, and f is the receiving coil. For example, the distance between any two coils (e.g., the distance between the center axes of the two coils) is less than or equal to 3 mm. In a specific embodiment, Figure 3The arrangement manner and measurement sequence of the multiple coils 2 in the multi-channel eddy current sensor array shown in the figure, the multi-channel eddy current sensor array includes a first row of coils and a second row of coils arranged in parallel in the second direction. Among them, the first row of coils and the second row of coils include a plurality of coils 2 arranged along the first direction, and the plurality of coils in the first row of coils are arranged in an interlaced manner with the plurality of coils in the second row of coils. Therefore, the two coils arranged in an interlaced manner in the first row of coils and the second row of coils can be formed into a coil pair, and each coil pair includes an excitation coil and a receiving coil. The three coils in adjacent coil pairs are arranged in an equilateral triangle, that is, the spacing between any coil and any of the two adjacent coils is the same. In one embodiment, adjacent coil pairs can share a coil, which can be used as a receiving coil for the previous coil pair or as an excitation coil for the next coil pair. As in the multi-channel eddy current sensor array set up as described above, the coils in adjacent coil pairs arranged in an equilateral triangle, the area near the midpoint of their connection has a higher sensitivity, such as Figure 4 As shown. Therefore, the combination of multiple adjacent coil pairs in the multi-channel eddy current sensor array enables the sensitivity near the midpoint area to effectively cover a certain range, ensuring that the multi-channel eddy current sensor array can cover the center position area of ​​the track along the first direction, thereby ensuring that the multi-channel eddy current sensor array can accurately collect key data in the lateral direction area of ​​the track, which is suitable for detecting fluctuations on the rail surface. In the embodiment of the present application, the structure and parameters of the coil pairs in the multi-channel eddy current sensor array will affect the coverage range of its sensitivity. Therefore, a suitable multi-channel eddy current sensor array can be selected based on parameters such as the size of the track.

[0104] In a specific embodiment, all coils in the multi-channel eddy current sensor array can be numbered in sequence and the coils can be excited in turn according to the numbering sequence. Figure 3 As shown, when coil a is used as an excitation coil, an alternating current is passed through coil a. The alternating current in coil a generates an alternating magnetic field (i.e., an excitation magnetic field). The excitation magnetic field generates induced eddy currents in the track. The induced eddy currents generate a reverse magnetic field, which is superimposed with the excitation magnetic field of the excitation coil to form a total magnetic field. The coils adjacent to coil a capture the changes in the total magnetic field to generate measurement data. For example, when coil a is used as an excitation coil, the coil b adjacent to it can be used as a receiving coil. For example, all coils are excited, and an adjacent coil of the excitation coil is used as a receiving coil. For example, coil a is first used as an excitation coil, and the adjacent coil b is used as a receiving coil. Then coil b is used as an excitation coil, and the adjacent coil c of coil b is used as a receiving coil... until all coils in the multi-channel eddy current sensor array are excited in sequence.

[0105] In another specific embodiment, rather than energizing a single excitation coil and then receiving data via a single receiving coil as described above, multiple coils can be simultaneously excited to acquire measurement data from multiple coils. Because there is a linear relationship between energizing a single coil and receiving data via a single coil and energizing multiple coils to acquire measurement data from multiple coils as described above, these two coil excitation and receiving methods can also be converted to each other.

[0106] In some embodiments, the measurement data includes one or more of an induced voltage, an inductance signal, or an impedance signal. In other embodiments, the measurement data may also include parameters such as the phase of the signal or the mismatch of the multi-channel sensor array (indicating the degree of deviation between the current state and the optimal alignment state).

[0107] In some embodiments, the induced voltage on the track surface collected by the multi-channel eddy current sensor array is caused by any receiving coil, the corresponding excitation coil and the object being measured. The induced voltage satisfies:

[0108]

[0109] Among them, I e is the current amplitude applied to the excitation coil, Ω is the surface of the measurement space, and E T 、E R is the electric field strength generated by the excitation coil and the receiving coil, Δσ is the conductivity of the track, j is the imaginary unit, ω is the excitation frequency, H T 、H R is the magnetic field strength generated by the excitation coil and the receiving coil, Δμ is the magnetic permeability of the track, and dV is the volume element. According to the above formula, the amplitude data of the induced voltage of all coil pairs in the multi-channel eddy current sensor array are collected, and step S2 is executed based on the amplitude data of the induced voltage of each coil pair.

[0110] It should be noted that due to the skin effect of the electromagnetic field, the induced magnetic field attenuates in the deep layer of the track. Therefore, the track surface in this application refers to the track surface and the range of 0 to 5 cm below the track surface.

[0111] S2. Interpolate the amplitude data of the collected measurement data to obtain a distribution of the amplitude of the measurement data along a first direction; the first direction is parallel to the top surface of the track and perpendicular to the extension direction of the track.

[0112] In some embodiments, in order to make the peak of the curve formed by continuous but limited measurement data correspond exactly to the center, it is necessary to perform interpolation processing on the real signal and / or imaginary signal of the measurement data, such as the induced voltage, inductance signal, impedance signal, phase of the signal, or mismatch of the multi-channel sensor array, to generate more points and form an interpolation curve, thereby obtaining the distribution of the amplitude of the measurement data along the first direction. For the selection of the real signal and the imaginary signal, refer to Figure 7 and Figure 8 As can be seen from the figure, the real signal changes more significantly than the imaginary signal at different starting point values. Therefore, the real signal is more suitable for determining the center position of the rail. For example, the amplitude data of the real signal of the collected induced voltage is processed by interpolation to obtain the following: Figure 6 The curve shown. Figure 6 In the figure, the abscissa is the offset displacement between the transverse center position of the multi-channel eddy current sensor array and the transverse center position of the track, and the ordinate is the real signal amplitude of the induced voltage corresponding to different offset displacements. Figure 6 The square icon in the middle represents the real signal amplitude of the induced voltage corresponding to each coil pair in the multi-channel eddy current sensor array, and the curve represents the measurement data curve obtained by interpolating each measured voltage using the interpolation method.

[0113] It should be noted that interpolation is a method for estimating the value of an unknown point by constructing a function using known discrete data points. It can construct a function between known data points, accurately passing through all points, and estimate intermediate or nearby values. In one specific embodiment, cubic interpolation can be used to obtain the measured data curve, ensuring the continuity and smoothness of the interpolation result.

[0114] In some embodiments, step S2 may specifically be to perform real-time interpolation processing on the amplitude data of the collected measurement data, thereby determining in real time whether the multi-channel eddy current sensor array is currently in the optimal alignment state based on the interpolated data.

[0115] S3. Determine the coordinates corresponding to the extreme value of the distribution of the amplitude of the measurement data along the first direction.

[0116] Optionally, the horizontal center position of the multi-channel eddy current sensor array is used as the reference point (i.e., the coordinate origin), and the coordinate of the collected voltage amplitude is the distance between the coordinate corresponding to the amplitude signal and the horizontal center position of the multi-channel eddy current sensor array. In some other embodiments, the coordinate origin can also be other reference points. Figure 6 It can be seen that the extreme value of the interpolation curve is located near the horizontal axis 0. At this time, the lateral center position of the multi-channel eddy current sensor array is closest to the lateral center position of the object being measured. In this way, the lateral center position of the track can be accurately determined by the position of the positioning coil pair.

[0117] In a specific embodiment, when the multi-channel eddy current sensor arrays are lifted at the same frequency and different frequencies, the real signal of the induced voltage shows a more significant change than the imaginary signal, so the real signal is used to determine the track center. Therefore, it is necessary to determine the coordinates corresponding to the extreme value of the distribution of the amplitude data of the real signal of the induced voltage along the first direction, such as Figure 6 As shown, in order to obtain a more accurate lateral center position of the track.

[0118] In some embodiments, due to the presence of measurement noise, the average measurement value may not be unique. Therefore, it is necessary to take the average of multiple measurement data for multiple measurements, or to apply an appropriate filter to eliminate noise artifacts, which helps to obtain a smooth curve and a unique extreme value. In a specific embodiment, the interpolated induced voltage data can be made to have a unique extreme value by using local weighted regression filtering, and the coordinates corresponding to the unique extreme value can be determined. In another embodiment, a "robust low baseline fitting" filter can also be used to generate a filtered curve with a single peak, such as Figure 9 As shown, the embodiment of the present application does not limit the filtering method of the interpolated measurement data, as long as the interpolated measurement data can have a unique extreme value.

[0119] S4. Determine the transverse center position of the track according to the coordinates corresponding to the extreme values; wherein the transverse center position of the track is the center position of the track in the first direction.

[0120] like Figure 6 As shown in the figure, when the horizontal axis is near 0, the curve has a unique extreme value, indicating that the amplitude of the induced voltage collected by a set of coil pairs is the only extreme value of the curve. At this time, the deviation between the coordinate corresponding to this extreme value and the coordinate origin is the deviation between the transverse center position of the multi-channel eddy current sensor array and the transverse center position of the track.

[0121] In some embodiments, after determining the lateral center position of the track according to the coordinates corresponding to the extreme values, the step further includes:

[0122] The multi-channel eddy current sensor array is controlled to perform real-time offset and feedback by generating a control signal in real time until the multi-channel eddy current sensor array is located at the lateral center position of the track. Specifically, when the probe of the multi-channel eddy current sensor array is located near the extreme value of the induced voltage amplitude, the multi-channel eddy current sensor array can be controlled by generating a control signal in real time to continue offsetting and provide real-time feedback until it is offset to the optimal centering position, thereby realizing a closed loop of "detection-feedback-adjustment", thereby improving the centering accuracy of the method and the continuity of detection. In a specific embodiment, the extreme value of the induced voltage amplitude can be the collected induced voltage amplitude less than or equal to ±1%, ±5%, ±10%, ... of the extreme value of the measured value. The embodiment of the present application does not limit the range near the extreme value, as long as the signal control of the multi-channel eddy current sensor array to the optimal centering position can be achieved when the probe performs real-time feedback.

[0123] In summary, the sensor alignment detection method provided by the present application, compared with the prior art which uses the differential signal of a single coil pair or a double coil pair to reflect the lateral center position of the object to be measured, the present application uses a small-size, high-density sensor coil array to significantly improve the spatial resolution of the measurement signal, and increases the sensitivity within the range of the lateral center position, thereby effectively improving the efficiency and accuracy of the detection of the object to be measured.

[0124] At the same time, the present application realizes the closed-loop control process of real-time signal acquisition, real-time signal analysis, real-time judgment of the centering status of the multi-channel eddy current sensor array, and real-time control of the multi-channel eddy current sensor array to adjust the centering position, thereby achieving continuous maintenance of the multi-channel eddy current sensor array in the optimal centering state under complex road conditions and maintaining uninterrupted detection, thereby ensuring the accuracy and reliability of the centering and improving the detection efficiency.

[0125] In addition, this application innovatively integrates the track alignment system and the flaw detection system into the same equipment platform, achieving functional integration and thus reducing the weight and cost of the equipment.

[0126] A second aspect of the embodiments of the present application provides a device for detecting a track, which is used in accordance with the device for detecting a track provided in the first aspect of the embodiments of the present application. The device includes:

[0127] A multi-channel eddy current sensor array for collecting measurement data from the track surface;

[0128] a preprocessing module, configured to perform interpolation processing on the amplitude data of the collected measurement data, thereby obtaining a distribution of the amplitude of the measurement data along a first direction;

[0129] an analysis module, configured to determine coordinates corresponding to extreme values ​​of the distribution of the amplitude of the measurement data along the first direction;

[0130] The calculation module is used to determine the horizontal center position of the track according to the coordinates corresponding to the extreme values.

[0131] Optionally, the measurement data includes one or more of an induced voltage, an inductance signal, or an impedance signal; or, the measurement data includes one or more of a phase of a signal or a mismatch amount of a multi-channel sensor array.

[0132] Optionally, the multi-channel eddy current sensor array is specifically used for:

[0133] Determine the layout and parameters of the multi-channel eddy current sensor array based on the track size;

[0134] energizing at least one coil in the multi-channel eddy current sensor array;

[0135] An electromagnetic response signal is received by at least one adjacent coil of the at least one coil.

[0136] In some optional embodiments, the multi-channel eddy current sensor array is further specifically used for:

[0137] All coils are numbered in sequence and the coils are excited in turn in the order of their numbers.

[0138] Optionally, the multi-channel eddy current sensor array is further specifically used for:

[0139] Any two adjacent coils form a coil pair;

[0140] Collect the amplitude data of the induced voltage of any set of coil pairs.

[0141] In the above embodiment, the induced voltage satisfies:

[0142]

[0143] Among them, I e is the current amplitude applied to the excitation coil, Ω is the surface of the measurement space, and E T 、E R is the electric field strength generated by the excitation coil and the receiving coil, Δσ is the conductivity of the track, j is the imaginary unit, ω is the excitation frequency, H T 、H R is the magnetic field strength generated by the excitation coil and the receiving coil, Δμ is the magnetic permeability of the track, and dV is the volume element.

[0144] In some optional embodiments, the preprocessing module is specifically configured to:

[0145] interpolating the real signal of the measurement data; and / or

[0146] Perform interpolation processing on the imaginary signal of the measurement data.

[0147] In some optional embodiments, the apparatus further includes a processing module for changing the lift-off height of the multi-channel eddy current sensor array and determining an actual value of the transverse center position of the rail according to different lift-off heights.

[0148] In some optional embodiments, the processing module is further configured to:

[0149] The multi-channel eddy current sensor array is controlled to perform real-time offset and feedback by generating a control signal in real time until the multi-channel eddy current sensor array is located at the lateral center of the track.

[0150] In some optional embodiments, the analysis module is specifically configured to:

[0151] The coordinates corresponding to the extreme values ​​of the distribution of the amplitude of the real signal of the measurement data along the first direction are determined.

[0152] In some optional embodiments, the analysis module is further configured to:

[0153] The local weighted regression filter is used to make the interpolated measurement data have a unique extreme value, and the coordinates corresponding to the unique extreme value are determined.

[0154] In the above embodiment, the multi-channel eddy current sensor array includes a first row of coils and a second row of coils arranged in parallel in the second direction; the first row of coils and the second row of coils respectively include a plurality of coils arranged along the first direction; and the three coils in the multi-channel eddy current sensor array that are closest to each other along the second direction are distributed in an equilateral triangle; in a plane perpendicular to the top surface of the track, the second direction is perpendicular to the first direction.

[0155] A third aspect of an embodiment of the present application provides a device for track centering, the device comprising:

[0156] A second aspect of the present application provides a device for detecting a track, for detecting a deviation between a track center and a center of a multi-channel eddy current sensor array;

[0157] The actuating mechanism is used for controlling the multi-channel eddy current sensor array to move in a first direction according to the deviation, so that the center of the multi-channel eddy current sensor array is aligned with the center of the track.

[0158] Example

[0159] A method for track centering provided in an embodiment of the present application is suitable for detecting the transverse center position of a rail so as to facilitate subsequent flaw detection of the rail.

[0160] like Figure 5As shown, the multi-channel eddy current sensor array 4 and the track 6 are arranged vertically, and the plane of the multi-channel eddy current sensor array 4 is perpendicular to the central axis of the track. The distance between the track 6 and the multi-channel eddy current sensor array 4 is the lift-off height 5 of the multi-channel eddy current sensor array, and the offset between the center position of the track 6 and the center position of the multi-channel eddy current sensor array 4 is the center-to-center lateral spacing.

[0161] according to Figure 5 , executing step S1, determining the lift-off height 6 of the multi-channel eddy current sensor array and the relative positions of the track 6 and the multi-channel eddy current sensor array 4. The multi-channel eddy current sensor array 4 provided in this application already covers the lateral center position range of the track 6, thereby ensuring the sensitivity coverage range of the multi-channel eddy current sensor array 4 and obtaining the accurate lateral center position of the track.

[0162] like Figure 3 As shown, the parameters of the multi-channel eddy current sensor array 4 and the excitation and measurement sequence are determined based on the lateral dimensions of the track and the corresponding structure and dimensions of the multi-channel eddy current sensor array 4. This embodiment of the present application provides a multi-channel eddy current sensor array comprising 16 coils, and its specific parameters and measurement sequence are shown in Tables 1 and 2.

[0163] Table 1 Parameter examples of multi-channel eddy current sensor array and track

[0164]

[0165]

[0166] Table 2 Example of coil excitation and measurement sequence in a multi-channel eddy current sensor array

[0167] # 1 2 3 4 5 6 7 8 9 9 11 12 13 14 15 Excitation coil a b c d e f g h i j k l m n o receiving coil b c d e f g h i j k l m n o p

[0168] After determining and providing the parameters of the multi-channel eddy current sensor array 4 and the measurement order of the coils, as well as the measurement positions of the track 6 and the multi-channel eddy current sensor array 4, the induced voltages of all coil pairs in the multi-channel eddy current sensor array 4 are collected through the multi-channel eddy current sensor array 4.

[0169] In the embodiment of the present application, the induced voltage of the receiving coil in any set of coil pairs can be calculated using the following formula:

[0170]

[0171] Among them, I e is the current amplitude applied to the excitation coil, Ω is the surface of the measurement space, and E T 、E Ris the electric field strength generated by the excitation coil and the receiving coil, Δσ is the conductivity of the track, j is the imaginary unit, ω is the excitation frequency, H T 、H R is the magnetic field strength generated by the excitation coil and the receiving coil, Δμ is the magnetic permeability of the track, and dV is the volume element.

[0172] The induced voltage is calculated according to the above formula and a discrete graph is drawn, as shown in the following example: Figure 6 As shown in the figure, the square icons represent the induced voltages between 15 adjacent coil pairs measured in the embodiment of the present application. The horizontal axis of the discrete graph represents the offset between the transverse center position of the multi-channel eddy current sensor array 4 and the transverse center position of the track 6, and the vertical axis represents the real signal amplitude of the induced voltage.

[0173] After obtaining the induced voltage in each pair of coils, the multi-channel eddy current sensor array 4 executes step S2 to obtain an interpolation curve by interpolation. The cubic interpolation is used and based on the amplitude data of the real part signal of the induced voltage of the 15 pairs of coils, a measurement curve containing 1500 data points is obtained, such as Figure 6 As shown in the curve. Figure 6 It can be seen that cubic interpolation is used to draw multiple discrete points into a continuous curve, which ensures the accuracy of the measurement.

[0174] After obtaining the measurement data curve, steps S3 and S4 are executed to determine the transverse center position of the track 6 according to the extreme value of the interpolation curve. Figure 5 and Figure 6 It can be seen that the extreme value of the interpolation curve is located near the horizontal center of the horizontal axis, which is 0. Figure 5 It can be concluded that the offset between the center position of the multi-channel eddy current sensor array 4 and the transverse center position of the track can be understood as: the offset between the transverse center position of the transverse axis corresponding to the induced voltage of the coil pair located at the transverse center position of the multi-channel eddy current sensor array 4 and the transverse center position of the multi-channel eddy current sensor array 4 corresponding to 0. Therefore, by determining the extreme value of the interpolation curve, the position of the coil pair corresponding to the extreme value of the curve can be determined, and thus the transverse center position of the track can be determined.

[0175] In other embodiments, by changing the liftoff height 5 of the multi-channel eddy current sensor array and the center position of the multi-channel eddy current sensor array 4, steps S1 to S4 are repeated to obtain different interpolation curves. For probe lifts within a range of 1 mm to 5 mm, the track center position can be estimated by acquiring a single frame of continuous measurement data from the coil array, eliminating the need to scan the track surface. Figure 10 and Figure 11The track center estimation results of the lateral position and lift-off height of different multi-channel eddy current sensor arrays are shown respectively. In order to ensure that the center position of the track is located in the sensitive area of ​​the coil array, reference is made to Figure 10 , it is necessary to measure and evaluate the distance between the track center and the center of the multi-channel eddy current sensor array between -6.32mm and 6.32mm. Figure 10 and Figure 11 It can be seen that when the multi-channel eddy current sensor array 4 is raised by 1mm, 3mm and 5mm respectively relative to the height of the above embodiment, the distance between the center position of the track 6 and the multi-channel eddy current sensor array 4 is less than 6mm. The track center estimation result calculated according to the method provided in this application is close to the actual value, and the paired estimation error value is less than 0.9mm, which ensures the alignment accuracy of the lateral center position of the track.

[0176] This application provides a method for detecting rails. This method uses a multi-channel eddy current system to collect measurement data from the method. It then uses interpolation and other methods to create a smooth measurement curve. The coordinates corresponding to the curve's extreme values ​​are then used to determine the rail's lateral center position. The estimated lateral center position obtained using this method is close to the actual value, with minimal error, improving measurement accuracy and providing reliable standard information for lateral alignment between the rail and the method.

[0177] Furthermore, the method for detecting rails in this application increases the lateral length, broadening the lateral coverage of the rails and improving the efficiency of detecting the lateral center position of the object being measured. Furthermore, compared to single or dual coil pairs, the coils in this application are smaller, significantly improving the spatial resolution of the measurement signal. This allows for both object centering and rail flaw detection, achieving the integration of a centering and flaw detection system.

[0178] The above is a schematic description of the present invention, but is not limited thereto. The accompanying drawings only show one embodiment of the present invention. If researchers in this field propose a structural form similar to the technical solution without departing from the purpose of the present invention, it should fall within the scope of protection of the present invention.

Claims

1. A method for detecting a track, characterized in that The method comprises: Collecting measurement data on the track surface through a multi-channel eddy current sensor array; Performing interpolation processing on the amplitude data of the collected measurement data to obtain a distribution of the amplitude of the measurement data along a first direction; the first direction is parallel to the top surface of the track and perpendicular to the extension direction of the track; determining coordinates corresponding to extreme values ​​of the distribution of the amplitude of the measurement data along the first direction; The transverse center position of the track is determined according to the coordinates corresponding to the extreme values; wherein the transverse center position of the track is the center position of the track in the first direction.

2. The method according to claim 1, characterized in that Determining the transverse center position of the track according to the coordinates corresponding to the extreme values ​​includes: The lateral center position of the track is determined according to the deviation between the coordinates corresponding to the extreme value and the center of the multi-channel eddy current sensor array, where the deviation is the position deviation between the center of the multi-channel eddy current sensor array and the lateral center of the track.

3. The method according to claim 1, characterized in that The measurement data includes one or more of an induced voltage, an inductance signal, or an impedance signal; or the measurement data includes one or more of a phase of a signal or a mismatch amount of the multi-channel sensor array.

4. The method according to claim 2, characterized in that The method of collecting the measurement data of the track surface by using the multi-channel eddy current sensor array includes: Determining the layout and parameters of the multi-channel eddy current sensor array based on the track size; energizing at least one coil in the multi-channel eddy current sensor array; An electromagnetic response signal is received by at least one adjacent coil of the at least one coil.

5. The method according to claim 4, characterized in that The exciting at least one coil in the multi-channel eddy current sensor array includes: numbering all the coils in sequence, and exciting the coils in turn according to the order of the numbers.

6. The method according to claim 3 or 4, characterized in that The receiving of the electromagnetic response signal by at least one adjacent coil of the at least one coil comprises: Any two adjacent coils form a coil pair; The amplitude data of the induced voltage of any group of the coil pairs is collected.

7. The method according to claim 6, characterized in that The induced voltage satisfies: Among them, I e is the current amplitude applied to the excitation coil, Ω is the surface of the measurement space, and E T 、E R is the electric field strength generated by the excitation coil and the receiving coil, Δσ is the conductivity of the track, j is the imaginary unit, ω is the excitation frequency, H T 、H R is the magnetic field strength generated by the excitation coil and the receiving coil, Δμ is the magnetic permeability of the track, and dV is the volume element.

8. The method according to claim 1, characterized in that The interpolation processing of the amplitude data of the collected measurement data includes: performing interpolation processing on the real signal of the measurement data; and / or An interpolation process is performed on the imaginary signal of the measurement data.

9. The method according to claim 1, characterized in that After determining the transverse center position of the track according to the coordinates corresponding to the extreme values, the method further includes: The lift-off height of the multi-channel eddy current sensor array is changed, and the actual value of the lateral center position of the track is determined according to the different lift-off heights.

10. The method according to claim 1, characterized in that After determining the transverse center position of the track according to the coordinates corresponding to the extreme values, the method further includes: The multi-channel eddy current sensor array is controlled to perform real-time offset and feedback by generating a control signal in real time until the multi-channel eddy current sensor array is located at the transverse center of the track.

11. The method according to claim 9, characterized in that Determining the coordinates corresponding to the extreme value of the distribution of the amplitude of the measurement data along the first direction includes: The coordinates corresponding to the extreme value of the distribution of the amplitude of the real signal of the measurement data along the first direction are determined.

12. The method according to claim 1, characterized in that Determining the coordinates corresponding to the extreme value of the distribution of the amplitude of the measurement data along the first direction includes: The interpolated measurement data is made to have a unique extreme value through local weighted regression filtering, and the coordinates corresponding to the unique extreme value are determined.

13. The method according to claim 1, wherein The multi-channel eddy current sensor array includes a first row of coils and a second row of coils arranged in parallel in a second direction; the first row of coils and the second row of coils respectively include a plurality of coils arranged along the first direction; and the three coils in the multi-channel eddy current sensor array that are closest to each other along the second direction are distributed in an equilateral triangle; in a plane perpendicular to the top surface of the track, the second direction is perpendicular to the first direction.

14. A device for detecting a track, used for detecting the center of the track according to the method according to any one of claims 1 to 13, characterized in that: The device comprises: A multi-channel eddy current sensor array for collecting measurement data from the track surface; a preprocessing module, configured to perform interpolation processing on the amplitude data of the collected measurement data, thereby obtaining a distribution of the amplitude of the measurement data along a first direction; an analysis module, configured to determine coordinates corresponding to extreme values ​​of the distribution of the amplitude of the measurement data along the first direction; A calculation module is used to determine the transverse center position of the track according to the coordinates corresponding to the extreme values.

15. A device for track centering, characterized in that The device comprises: The device for detecting a track according to claim 14, configured to detect a deviation between a center of the track and a center of a multi-channel eddy current sensor array; An actuating mechanism is used for controlling the displacement of the multi-channel eddy current sensor array in a first direction according to the deviation, so that the center of the multi-channel eddy current sensor array is aligned with the center of the track.

Images