CN110568059A - Nondestructive testing method and device for steel wire rope - Google Patents

Nondestructive testing method and device for steel wire rope Download PDF

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Publication number
CN110568059A
CN110568059A CN201910904849.4A CN201910904849A CN110568059A CN 110568059 A CN110568059 A CN 110568059A CN 201910904849 A CN201910904849 A CN 201910904849A CN 110568059 A CN110568059 A CN 110568059A
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Prior art keywords
wire rope
steel wire
magnetic flux
detected
defect
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张东来
张恩超
潘世旻
晏小兰
高伟
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Shenzhen Graduate School Harbin Institute of Technology
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Shenzhen Graduate School Harbin Institute of Technology
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Priority to CN201910904849.4A priority Critical patent/CN110568059A/en
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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01BMEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00Measuring arrangements characterised by the use of electric or magnetic means
    • G01B7/02Measuring arrangements characterised by the use of electric or magnetic means for measuring length, width or thickness
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/83Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws by investigating stray magnetic fields

Abstract

the invention provides a nondestructive testing method and a nondestructive testing device for a steel wire rope, wherein the method comprises the following steps of: acquiring a magnetic flux signal of a steel wire rope to be detected through a magnetic flux detection sensor, and acquiring a magnetic leakage signal of the steel wire rope to be detected through a magnetic field intensity detection sensor; preprocessing the magnetic flux signal and the magnetic leakage signal, obtaining a magnetic flux characteristic value according to the preprocessed magnetic flux signal, and obtaining a magnetic leakage characteristic value according to the preprocessed magnetic leakage signal; obtaining the defect width of the steel wire rope to be tested according to the magnetic flux characteristic value and the magnetic leakage characteristic value; comparing the defect width of the detected steel wire rope with a preset width threshold value; if the defect width is larger than or equal to a preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value; and if the defect width is smaller than a preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value and the magnetic leakage characteristic value. The invention can identify all types of defects of the detected steel wire rope, and has high quantitative accuracy of section loss.

Description

nondestructive testing method and device for steel wire rope
Technical Field
The invention belongs to the technical field of steel wire rope detection, and particularly relates to a method and a device for carrying out steel wire rope nondestructive detection on a steel wire rope by detecting magnetic flux and magnetic leakage field quantity.
Background
The steel wire rope is widely applied to the fields of industry, civilian use, military use and the like. Over the service life, various damages to the steel wire rope are inevitable, which can significantly reduce the mechanical properties of the material, such as strength, toughness, plasticity and the like, and seriously affect the safe use of the material, so that the steel wire rope needs to be checked regularly. The cross-section loss of the steel wire rope defect directly influences the quality of the steel wire rope, so that the quantitative detection of the cross-section loss of the steel wire rope defect is most important.
Electromagnetic detection is the most commonly used and effective method, and includes both saturated excitation and unsaturated excitation conditions. Under the unsaturated excitation condition, strict requirements are imposed on a detection sensor, environment, a mode and the like, and an accurate quantitative result cannot be obtained; the defect under the unsaturated excitation condition can be avoided under the saturated excitation condition, the precision of quantitative detection can be improved, and the method is better applied to actual detection.
under the condition of saturated excitation, the method can be divided into two methods of magnetic flux detection and magnetic flux leakage detection. The magnetic flux detection mainly detects the amount of change in magnetic flux of an object to be detected, the magnetic flux including main magnetic flux, leakage magnetic flux, yoke magnetic flux, and the like. The method has the advantages that when the axial width of the detected defect is larger, the detected flux value is directly related to the section loss area of the detected object, so that the section loss area of the detected object can be directly calculated through the detected flux value; however, when the axial width of the defect is small, the detected flux value is not only related to the cross-sectional loss area of the measured object, but also related to the axial width of the defect, which presents a complex nonlinear relationship, and the cross-sectional loss area cannot be quantitatively detected, or the detection accuracy is very low. The magnetic leakage detection mainly detects the magnetic leakage field intensity on the surface of a detected object through a sensor array. The advantage of this method is a high recognition rate for defects with small axial width. However, for defects with large axial width, the information of the defects cannot be accurately identified, and the cross-section loss amount cannot be quantitatively detected, so that the quantitative analysis can be performed only by complex calculation methods such as a neural network. This method can only identify surface defects and cannot identify internal defects. The method can train specific artificial neural network classification identification only by making a large number of standard defects, and if the type of the steel wire rope is changed, the artificial neural network needs to be retrained.
therefore, the current electromagnetic detection method cannot quantitatively detect the loss of all defective sections of the steel wire rope, and has low detection precision and complex calculation.
Disclosure of Invention
the invention aims to provide a nondestructive testing method and a nondestructive testing device for a steel wire rope, and aims to combine magnetic flux detection and magnetic flux leakage detection to identify all types of defects of the tested steel wire rope and improve quantitative accuracy of section loss.
The invention is realized in such a way that a steel wire rope nondestructive testing method comprises the following steps:
step S10, acquiring a magnetic flux signal of the steel wire rope to be detected through a magnetic flux detection sensor, and acquiring a magnetic leakage signal of the steel wire rope to be detected through a magnetic field intensity detection sensor;
step S20, preprocessing the magnetic flux signal and the magnetic leakage signal of the steel wire rope to be detected, obtaining the magnetic flux characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux signal, and obtaining the magnetic leakage characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic leakage signal;
Step S30, obtaining the defect width of the tested steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value;
Step S40, comparing the defect width of the detected steel wire rope with a preset width threshold value;
If the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected;
and if the defect width of the detected steel wire rope is smaller than the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect.
in a further technical solution of the present invention, in step S20, the step of preprocessing the magnetic flux signal of the measured wire rope includes:
carrying out outlier rejection, noise filtering and baseline elimination on the magnetic flux signal of the steel wire rope to be detected;
the step of removing the wild points of the magnetic flux signals of the detected steel wire rope comprises the following steps:
Removing wild points of a magnetic flux signal Y of the steel wire rope to be detected, and setting Y (i) as an ith magnetic flux acquisition signal, so that a delta Y is | Y (i) -Y (i +1) |, wherein the delta Y is an absolute value of a difference value of the magnetic flux signals of two adjacent magnetic flux signal acquisition points; for any i, if Δ Y is less than or equal to M, M is a preset threshold, and if the point Yi exists: y (i) -Y (i-1) | > M, and Y (i) -Y (i +1) | > M, when:
obtaining a signal Y after the wild point elimination processing1(i);
The step of carrying out noise filtering on the magnetic flux signal of the steel wire rope to be detected comprises the following steps:
and performing noise filtering on the magnetic flux signal of the steel wire rope to be detected by adopting self-adaptive filtering, wavelet transformation, smoothing filtering or empirical mode decomposition, wherein a calculation formula for performing noise filtering on the magnetic flux signal of the steel wire rope to be detected by adopting smoothing filtering is as follows:
wherein N is the number of data for averaging, and N is the total number of sampling points;
the step of eliminating the magnetic flux signal of the tested steel wire rope by the base line comprises the following steps:
performing baseline elimination on the magnetic flux signal of the steel wire rope to be detected by adopting envelope spectrum extraction, wavelet decomposition, window averaging or empirical mode decomposition, wherein the step of performing baseline elimination on the magnetic flux signal of the steel wire rope to be detected by adopting empirical mode decomposition comprises the following steps of:
finding the signal data sequence Y2(i) fitting all the maximum value points and minimum value points to an upper envelope line and a lower envelope line of the original sequence by a cubic spline function respectively; the mean of the upper and lower envelopes is m 1; data sequence Y2(i) subtracting m1 to obtain a new sequence Y with low frequency subtracted3(i) I.e. Y3(i)=Y2(i)-m1。
The further technical scheme of the invention is that the magnetic flux characteristic value at least comprises one or more of peak-to-peak value, width, average value, area and mean square deviation of each defect waveform of the steel wire rope to be detected, and the step of obtaining the magnetic flux characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux signal comprises the following steps:
setting a preset threshold value, and extracting sampling points larger than the preset threshold value, wherein the preset threshold value is obtained through the test of the minimum defect of the actually tested steel wire rope;
according to the extracted sampling point position information, intercepting N points on the left and right sides of the waveform axial direction to obtain each defect waveform, wherein N is obtained through the test of the maximum defect of the actually tested steel wire rope;
and extracting the peak value, the width, the average value, the area and the mean square error of each defect waveform.
the further technical scheme of the present invention is that, in step S20, the step of preprocessing the magnetic flux leakage signal of the tested steel wire rope includes:
Performing outlier rejection, noise filtering, baseline elimination and strand noise filtering on each path of magnetic flux leakage signals of the steel wire rope to be detected;
the step of eliminating the magnetic leakage signals of each path of the detected steel wire rope comprises the following steps:
eliminating the wild points of each path of magnetic leakage signal X, and setting Xi,jIs the jth sampled value of the ith Hall sensor, so that Δ X ═ Xi,j—Xi,(j+1)where Δ X is the absolute difference between two adjacent sampled values of the ith Hall sensora value; for any i, j, if Δ X is less than or equal to F, where F is a preset threshold, then:
Obtaining a signal X after the outlier rejectioni,j
The step of carrying out noise filtering on each path of leakage magnetic signal of the tested steel wire rope comprises the following steps:
carrying out noise filtering on each path of magnetic flux leakage signal of the steel wire rope to be tested by adopting self-adaptive filtering, or wavelet transformation, or smooth filtering, or empirical mode decomposition; the calculation formula for carrying out noise filtering on each path of magnetic leakage signal of the detected steel wire rope by adopting smooth filtering is as follows:
Wherein N is the number of data for averaging, N is the number of total sampling points, and k is the number of magnetic field intensity detection sensor paths for collecting the magnetic leakage signal of the steel wire rope to be detected;
the step of eliminating the baseline of each path of magnetic leakage signal of the tested steel wire rope comprises the following steps:
performing baseline elimination on each path of magnetic leakage signal of the tested steel wire rope by adopting envelope spectrum extraction, wavelet decomposition, window averaging or empirical mode decomposition; the step of eliminating the baseline of each path of magnetic leakage signal of the tested steel wire rope by adopting empirical mode decomposition comprises the following steps:
finding out all maximum value points and minimum value points of the original magnetic leakage signal data sequence X, and respectively fitting the maximum value points and minimum value points into an upper envelope line and a lower envelope line of the original sequence by using a cubic spline function, wherein the mean value of the upper envelope line and the lower envelope line is m 1; subtracting m1 from the original data sequence to obtain a new sequence X with low frequency subtracted1I.e. X1=X-m1;
the step of filtering the strand wave noise of each path of magnetic leakage signal of the tested steel wire rope comprises the following steps:
Adopt wavelet decomposition, or empirical mode decomposition, or adaptive filtering, or the gradient method is right every way magnetic leakage signal of being surveyed wire rope carries out the spike noise filtering, wherein, adopt the gradient method right every way magnetic leakage signal of being surveyed wire rope carries out the step of spike noise filtering and includes:
using gradient method to realize first order differentiation of image, for image X1(x, y) whose gradient at coordinate (x, y) is a two-dimensional column vector representation:
the modulus of this vector is:
and summing the multipath leakage magnetic signals to obtain a leakage magnetic sum signal X2.
a further technical solution of the present invention is that, in step S20, the magnetic flux leakage characteristic value of the measured wire rope at least includes a peak-to-peak value, a width, an average value, an area, and a mean square error of each defect waveform of the measured wire rope, and the step of obtaining the magnetic flux leakage characteristic value of the defect of the measured wire rope according to the preprocessed magnetic flux leakage signal includes:
The method comprises the steps of positioning defects by adopting a local maximum value method, and setting a preset threshold value to judge whether the defects exist, wherein the preset threshold value is obtained through testing the minimum defects of the actual steel wire rope;
Taking the found defect position as a central point, intercepting L points on the left and right sides of the axial direction of the waveform to obtain each defect waveform, wherein L is obtained through the test of the maximum defect of the actual steel wire rope;
And extracting the peak value, the width, the average value, the area and the mean square error of each defect waveform of the detected steel wire rope.
a further technical solution of the present invention is that, in the step S30, the step of obtaining the defect width of the measured wire rope from the magnetic flux characteristic value and the magnetic leakage characteristic value includes:
And inputting the waveform width and the waveform area of the magnetic flux characteristic value and the waveform width and the waveform area of the magnetic flux characteristic value into a defect width calculation equation or a neural network to obtain the defect width of the detected steel wire rope.
A further technical solution of the present invention is that, in step S40, if the defect width of the measured steel wire rope is greater than or equal to the preset width threshold, the step of obtaining the cross-section loss amount of the measured steel wire rope according to the magnetic flux characteristic value of the measured steel wire rope includes:
and if the defect width of the detected steel wire rope is larger than or equal to the preset width threshold, inputting a waveform peak value, a waveform area, a waveform average value and a waveform mean square error in the magnetic flux characteristic value into a defect section loss quantity magnetic flux calculation equation or a neural network to obtain the section loss quantity of the detected steel wire rope defect.
A further technical solution of the present invention is that, in step S40, if the defect width of the measured steel wire rope is smaller than the preset width threshold, the step of obtaining the cross-section loss amount of the measured steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the measured steel wire rope includes:
And if the defect width of the steel wire rope to be detected is smaller than the preset width threshold, inputting a waveform peak value, a waveform area, a waveform average value, a waveform mean square error and a waveform peak value, a waveform area, a waveform average value and a waveform mean square error in the magnetic flux characteristic value into a defect section loss quantity calculation equation or a neural network to obtain the section loss quantity of the steel wire rope to be detected.
In order to achieve the above object, the present invention further provides a steel wire rope nondestructive testing apparatus, which includes a magnetic flux detection sensor, a magnetic field strength detection sensor, and a signal acquisition and processing system, wherein the magnetic flux detection sensor is configured to acquire a magnetic flux signal of a tested steel wire rope, and the magnetic field strength detection sensor is configured to acquire a magnetic flux leakage signal of the tested steel wire rope;
the signal acquisition and processing system comprises a signal acquisition unit, a signal preprocessing unit, a characteristic value calculating unit and a defect section loss quantitative analysis unit, wherein,
The signal preprocessing unit is used for preprocessing the magnetic flux signal and the magnetic leakage signal of the steel wire rope to be detected;
The characteristic value calculating unit is used for obtaining a magnetic flux characteristic value of the detected steel wire rope defect according to the preprocessed magnetic flux signal and obtaining a magnetic leakage characteristic value of the detected steel wire rope defect according to the preprocessed magnetic leakage signal;
the defect section loss quantitative analysis unit is used for obtaining the defect width of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value;
The defect section loss quantitative analysis unit is also used for comparing the defect width of the detected steel wire rope with a preset width threshold value;
if the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected;
And if the defect width of the detected steel wire rope is smaller than the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect.
according to a further technical scheme, the device further comprises an excitation structure used for exciting the steel wire rope to be detected to saturation or near saturation.
the nondestructive testing method and the nondestructive testing device for the steel wire rope have the beneficial effects that: according to the technical scheme, the magnetic flux signal of the steel wire rope to be detected is obtained through the magnetic flux detection sensor, and the magnetic flux leakage signal of the steel wire rope to be detected is obtained through the magnetic field intensity detection sensor; preprocessing the magnetic flux signal and the magnetic flux leakage signal of the steel wire rope to be detected, obtaining a magnetic flux characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux signal, and obtaining a magnetic flux leakage characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux leakage signal; obtaining the defect width of the steel wire rope to be tested according to the magnetic flux characteristic value and the magnetic leakage characteristic value; comparing the defect width of the detected steel wire rope with a preset width threshold value; if the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected; if the defect width of the detected steel wire rope is smaller than the preset width threshold value, the section loss amount of the detected steel wire rope is obtained according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect, and by combining magnetic flux detection and magnetic leakage detection, not only can all types of defects of the detected steel wire rope be identified, but also the method has the advantages of high section loss quantitative precision, simple quantitative method and no need of complex calculation method or training of fitting samples.
Drawings
FIG. 1 is a schematic flow chart of a method for nondestructive testing of a steel wire rope according to a preferred embodiment of the present invention;
FIG. 2 is a schematic structural view of a nondestructive testing apparatus for a steel wire rope according to the present invention;
FIG. 3 is a schematic structural view of a magnetic flux detecting sensor in a nondestructive testing apparatus for a steel wire rope according to the present invention;
FIG. 4 is a schematic structural view of a magnetic flux leakage detecting sensor in a nondestructive testing apparatus for a wire rope according to the present invention;
FIG. 5 is a schematic structural diagram of a signal acquisition and processing system in a nondestructive testing device for steel wire ropes according to the present invention.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
in consideration of the fact that the conventional electromagnetic detection method cannot quantitatively detect the section loss of all defects of the steel wire rope, and the detection precision is low and the calculation is complex, the invention provides the method and the device for performing nondestructive detection on the steel wire rope by detecting the magnetic flux and the magnetic leakage field quantity.
Specifically, referring to fig. 1, fig. 1 is a schematic flow chart of a nondestructive testing method for a steel wire rope according to a preferred embodiment of the present invention.
As shown in fig. 1, in this embodiment, the method for performing nondestructive testing on a steel wire rope includes the following steps:
and step S10, acquiring a magnetic flux signal of the steel wire rope to be detected through the magnetic flux detection sensor, and acquiring a magnetic leakage signal of the steel wire rope to be detected through the magnetic field intensity detection sensor.
it can be understood that, in the present embodiment, the system structure of the whole detection device to which the steel wire rope nondestructive detection method is applied includes the excitation structure 1, the sensor 2, and the signal acquisition and processing system 3 as shown in fig. 2. Wherein, excitation structure 1 may adopt a conventional saturation excitation structure, including but not limited to: static excitation, alternating current excitation, and the like, as shown in fig. 2, the excitation structure 1 excites the wire rope to saturation or near saturation. The sensor 2 shown in fig. 2 includes a magnetic flux detection sensor and a magnetic field strength detection sensor, wherein the magnetic flux detection sensor includes, but is not limited to: fluxgate sensors, induction coils, etc. As shown in fig. 3, the magnetic flux detection sensor 201 is located inside the detection device, and the magnetic flux detection includes but is not limited to: main magnetic flux, leakage magnetic flux, yoke magnetic flux, etc. Magnetic field strength detection sensors include, but are not limited to: hall sensors, magnetoresistive sensors, giant magnetoresistive sensors, tunneling magnetoresistive sensors, and the like. As shown in fig. 4, an array 202 of magnetic field strength detection sensors is distributed on the surface of the steel wire rope, and the magnetic field strength detection includes but is not limited to: three-dimensional magnetic field intensity in different directions. The signal acquisition and processing system shown in fig. 5 includes a signal acquisition unit 301, a signal preprocessing unit 302, a feature value calculation unit 303, and a defect cross-section loss quantitative analysis unit 304.
it can be understood that, in this embodiment, can acquire the magnetic flux signal of being surveyed wire rope through magnetic flux detection sensor earlier, rethread magnetic field intensity detection sensor acquires the magnetic leakage signal of being surveyed wire rope also can acquire earlier through magnetic field intensity detection sensor the magnetic leakage signal of being surveyed wire rope, rethread magnetic flux detection sensor acquires the magnetic flux signal of being surveyed wire rope, perhaps when acquiring the magnetic flux signal of being surveyed wire rope through magnetic flux detection sensor, acquires through magnetic field intensity detection sensor the magnetic leakage signal of being surveyed wire rope, this embodiment does not limit to this.
And step S20, preprocessing the magnetic flux signal and the magnetic leakage signal of the detected steel wire rope, obtaining the magnetic flux characteristic value of the detected steel wire rope defect according to the preprocessed magnetic flux signal, and obtaining the magnetic leakage characteristic value of the detected steel wire rope defect according to the preprocessed magnetic leakage signal.
In this embodiment, the step of preprocessing the magnetic flux signal of the detected steel wire rope includes: and carrying out outlier rejection, noise filtering and baseline elimination on the magnetic flux signal of the steel wire rope to be detected.
by carrying out outlier rejection, noise filtering and baseline elimination on the magnetic flux signal of the detected steel wire rope, the signal-to-noise ratio of the magnetic flux signal can be improved, and the characteristic extraction of the signal is facilitated.
Specifically, the step of removing the magnetic flux signal of the detected steel wire rope comprises the following steps:
removing wild points of a magnetic flux signal Y of the steel wire rope to be detected, and setting Y (i) as an ith magnetic flux acquisition signal, so that a delta Y is | Y (i) -Y (i +1) |, wherein the delta Y is an absolute value of a difference value of the magnetic flux signals of two adjacent magnetic flux signal acquisition points; for any i, if Δ Y ≦ M exists, M is a preset threshold that may be set according to the sensitivity of the magnetic flux sensor, if there is a point Yi: y (i) -Y (i-1) | > M, and Y (i) -Y (i +1) | > M, when:
obtaining a signal Y after the wild point elimination processing1(i)。
The step of carrying out noise filtering on the magnetic flux signal of the steel wire rope to be detected comprises the following steps:
and performing noise filtering on the magnetic flux signal of the steel wire rope to be detected by adopting self-adaptive filtering, wavelet transformation, smoothing filtering or empirical mode decomposition, wherein a calculation formula for performing noise filtering on the magnetic flux signal of the steel wire rope to be detected by adopting smoothing filtering is as follows:
Wherein N is the number of data for averaging, and N is the number of total sampling points.
in this embodiment, the noise filtering of the magnetic flux signal of the measured steel wire rope includes, but is not limited to, adaptive filtering, wavelet transformation, smoothing filtering, empirical mode decomposition, or other methods.
the step of eliminating the magnetic flux signal of the tested steel wire rope by the base line comprises the following steps:
Performing baseline elimination on the magnetic flux signal of the steel wire rope to be detected by adopting envelope spectrum extraction, wavelet decomposition, window averaging or empirical mode decomposition, wherein the step of performing baseline elimination on the magnetic flux signal of the steel wire rope to be detected by adopting empirical mode decomposition comprises the following steps of:
Finding the signal data sequence Y2(i) fitting all the maximum value points and minimum value points to an upper envelope line and a lower envelope line of the original sequence by a cubic spline function respectively; the mean of the upper and lower envelopes is m 1; data sequence Y2(i) Subtracting m1 to obtain a new sequence Y with low frequency subtracted3(i) I.e. Y3(i)=Y2(i)-m1。
in this embodiment, the method for baseline cancellation of the magnetic flux signal of the measured steel wire rope includes, but is not limited to, methods such as envelope spectrum extraction, wavelet decomposition, window averaging, or empirical mode decomposition.
in this embodiment, for the preprocessed magnetic flux signal, a magnetic flux characteristic value of a defect may be obtained by a magnetic flux characteristic value analysis method, where the magnetic flux characteristic value at least includes one or more of a peak-to-peak value, a width, an average value, an area, and a mean square error of each defect waveform of the detected steel wire rope, and the step of obtaining the magnetic flux characteristic value of the detected steel wire rope defect according to the preprocessed magnetic flux signal includes:
Setting a preset threshold value, and extracting sampling points larger than the preset threshold value, wherein the preset threshold value is obtained through the test of the minimum defect of the actually tested steel wire rope;
Specifically, the preset threshold value can be set to be a proper threshold value according to the peak value of the minimum defect magnetic flux waveform of the steel wire rope to be detected;
According to the extracted sampling point position information, intercepting N points on the left and right sides of the waveform axial direction to obtain each defect waveform, wherein N is obtained through the test of the maximum defect of the actually tested steel wire rope;
and extracting the peak value, the width, the average value, the area and the mean square error of each defect waveform.
further, in this embodiment, in step S20, the step of preprocessing the magnetic leakage signal of the measured steel wire rope includes:
And carrying out outlier rejection, noise filtering, baseline elimination and strand noise filtering on each path of magnetic flux leakage signals of the steel wire rope to be detected. Therefore, the signal-to-noise ratio of the leakage magnetic signal can be improved, and the characteristic extraction of the signal is facilitated.
It can be understood that, in this embodiment, the magnetic leakage signal of the detected steel wire rope can be acquired by using a single magnetic field strength detection sensor or a multi-channel magnetic field strength detection sensor array, and for convenience in subsequent signal processing or quantitative process, the single magnetic sensor in the magnetic field strength detection sensor array is one channel or one channel in this embodiment.
Specifically, in this embodiment, the step of performing outlier rejection on each magnetic leakage signal of the detected steel wire rope includes:
eliminating the wild points of each path of magnetic leakage signal X, and setting Xi,jIs the jth sampled value of the ith Hall sensor, so that Δ X ═ Xi,j—Xi,(j+1)the absolute value of the difference between two adjacent sampling values of the ith Hall sensor is delta X; for any i, j, if Δ X ≦ F exists, F is a preset threshold, wherein the preset threshold may be set according to the sensitivity of the leakage magnetic sensor, and at this time:
Obtaining a signal X after the outlier rejectioni,j
In this embodiment, the step of performing noise filtering on each path of leakage magnetic signal of the detected steel wire rope includes:
Carrying out noise filtering on each path of magnetic flux leakage signal of the steel wire rope to be tested by adopting self-adaptive filtering, or wavelet transformation, or smooth filtering, or empirical mode decomposition; the calculation formula for carrying out noise filtering on each path of magnetic leakage signal of the detected steel wire rope by adopting smooth filtering is as follows:
Wherein, N is the data number of averaging, N is the total number of sampling points, and k is the magnetic field intensity detection sensor path number of magnetic leakage signal of the detected steel wire rope.
it should be understood that, in this embodiment, the method for filtering the noise of each path of leakage magnetic signal of the tested steel wire rope includes, but is not limited to, adaptive filtering, wavelet transform, smoothing filtering, empirical mode decomposition, and the like, and the present invention is not limited thereto.
In this embodiment, the step of eliminating the baseline of each magnetic leakage signal of the detected steel wire rope includes:
performing baseline elimination on each path of magnetic leakage signal of the tested steel wire rope by adopting envelope spectrum extraction, wavelet decomposition, window averaging or empirical mode decomposition; the step of eliminating the baseline of each path of magnetic leakage signal of the tested steel wire rope by adopting empirical mode decomposition comprises the following steps:
finding out all maximum value points and minimum value points of the original magnetic leakage signal data sequence X, and respectively fitting the maximum value points and minimum value points into an upper envelope line and a lower envelope line of the original sequence by using a cubic spline function, wherein the mean value of the upper envelope line and the lower envelope line is m 1; subtracting m1 from the original data sequence to obtain a new sequence X with low frequency subtracted1i.e. X1=X-m1。
It can be understood that, in this embodiment, the method for performing baseline cancellation on each magnetic leakage signal of the measured steel wire rope includes, but is not limited to, methods such as envelope spectrum extraction, wavelet decomposition, window averaging, or empirical mode decomposition, and the like, which is not limited in this disclosure.
in this embodiment, the step of filtering the strand wave noise of each magnetic leakage signal of the detected steel wire rope includes:
Adopt wavelet decomposition, or empirical mode decomposition, or adaptive filtering, or the gradient method is right every way magnetic leakage signal of being surveyed wire rope carries out the spike noise filtering, wherein, adopt the gradient method right every way magnetic leakage signal of being surveyed wire rope carries out the step of spike noise filtering and includes:
using gradient method to realize first order differentiation of image, for image X1(x, y) whose gradient at coordinate (x, y) is a two-dimensional column vector representation:
the modulus of this vector is:
and summing the multipath leakage magnetic signals to obtain a leakage magnetic sum signal X2.
It should be understood that, in this embodiment, the method for filtering the strake noise of each path of the leakage magnetic signal of the measured steel wire rope includes, but is not limited to, wavelet decomposition, empirical mode decomposition, adaptive filtering, or a gradient method, which is not limited in this invention.
in this embodiment, for the magnetic leakage signal after the preprocessing, the magnetic leakage characteristic value of the defect may be obtained by a magnetic leakage characteristic value analysis method, and the magnetic leakage characteristic value of the detected steel wire rope at least includes a peak value, a width, an average value, an area, and a mean square error of each defect waveform of the detected steel wire rope.
Specifically, the step of obtaining the magnetic leakage characteristic value of the detected steel wire rope defect according to the preprocessed magnetic leakage signal includes:
the method comprises the steps of positioning defects by adopting a local maximum value method, and setting a preset threshold value to judge whether the defects exist, wherein the preset threshold value is obtained through testing the minimum defects of the actual steel wire rope;
taking the found defect position as a central point, intercepting L points on the left and right sides of the axial direction of the waveform to obtain each defect waveform, wherein L is obtained through the test of the maximum defect of the actual steel wire rope;
and extracting the peak value, the width, the average value, the area and the mean square error of each defect waveform of the detected steel wire rope.
Specifically, in this embodiment, a suitable preset threshold may be set according to the peak-to-peak value of the minimum defect leakage magnetic waveform of the detected wire rope, and when the local maximum point of the acquired magnetic flux signal is greater than or equal to the preset threshold, it is determined that the local maximum point is a defect, where the local maximum point is obtained by comparing the areas of the acquired points.
and step S30, obtaining the defect width of the tested steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value.
After the magnetic flux characteristic value and the magnetic leakage characteristic value are obtained, the defect width of the tested steel wire rope can be obtained according to the magnetic flux characteristic value and the magnetic leakage characteristic value.
Specifically, the step of obtaining the defect width of the steel wire rope to be tested according to the magnetic flux characteristic value and the magnetic leakage characteristic value includes:
And inputting the waveform width and the waveform area of the magnetic flux characteristic value and the waveform width and the waveform area of the magnetic flux characteristic value into a defect width calculation equation or a neural network to obtain the defect width of the detected steel wire rope.
wherein, a simple calculation method is as follows: the waveform width SW of the magnetic flux characteristic value, the waveform width FW of the magnetic flux leakage characteristic value, and the lift-off DL of the magnetic flux leakage sensor are obtained, and the defect width W is (SW + FW-DL)/2. If more accurate defect width is required, calculation can be performed by testing several standard defect samples or simulating to obtain a calculation equation or a neural network.
And step S40, comparing the defect width of the detected steel wire rope with a preset width threshold value.
and if the defect width of the detected steel wire rope is larger than or equal to the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value of the detected steel wire rope defect.
specifically, if the defect width of the detected steel wire rope is greater than or equal to the preset width threshold, inputting a waveform peak value, a waveform area, a waveform average value and a waveform mean square error in the magnetic flux characteristic value into a defect section loss amount magnetic flux calculation equation or a neural network, and obtaining the section loss amount of the detected steel wire rope defect.
the preset width threshold value can be obtained by subtracting the width of the excitation magnetic pole from the length of the excitation probe.
wherein, a simple calculation method is as follows: and obtaining a waveform peak value VPP in the magnetic flux characteristic value, wherein the section loss LS of the detected steel wire rope defect is k1 multiplied by VPP + LB1, and k1 and LB1 are obtained by testing several standard defect samples or simulation.
and if the defect width of the detected steel wire rope is smaller than the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect.
Specifically, if the defect width of the steel wire rope to be measured is smaller than the preset width threshold, inputting a waveform peak value, a waveform area, a waveform average value, a waveform mean square error in the magnetic flux characteristic value and a waveform peak value, a waveform area, a waveform average value and a waveform mean square error in the magnetic flux characteristic value into a defect section loss amount calculation equation or a neural network, so as to obtain the section loss amount of the steel wire rope to be measured.
wherein, a simple calculation method: obtaining a waveform peak value SVPP in the magnetic flux characteristic value, a waveform peak value FVPP in the magnetic flux leakage characteristic value, and a section loss LS of the defect which is k2 x (SVPP + FVPP x s) + LB2, wherein k2, s and LB2 are obtained by testing several standard defect samples or simulation.
The nondestructive testing method for the steel wire rope has the beneficial effects that through the technical scheme, the magnetic flux signal of the tested steel wire rope is obtained through the magnetic flux detection sensor, and the magnetic flux leakage signal of the tested steel wire rope is obtained through the magnetic field intensity detection sensor; preprocessing the magnetic flux signal and the magnetic flux leakage signal of the steel wire rope to be detected, obtaining a magnetic flux characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux signal, and obtaining a magnetic flux leakage characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux leakage signal; obtaining the defect width of the steel wire rope to be tested according to the magnetic flux characteristic value and the magnetic leakage characteristic value; comparing the defect width of the detected steel wire rope with a preset width threshold value; if the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected; if the defect width of the detected steel wire rope is smaller than the preset width threshold value, the section loss amount of the detected steel wire rope is obtained according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect, and by combining magnetic flux detection and magnetic leakage detection, not only can all types of defects of the detected steel wire rope be identified, but also the method has the advantages of high section loss quantitative precision, simple quantitative method and no need of complex calculation method or training of fitting samples.
In order to achieve the above object, the present invention further provides a nondestructive testing apparatus for steel wire rope, referring to fig. 2 to 5 again, as shown in fig. 2 to 5, the nondestructive testing apparatus for steel wire rope of the present invention comprises an excitation structure 1, a sensor 2, and a signal acquisition and processing system 3 as shown in fig. 2. Wherein, excitation structure 1 may adopt a conventional saturation excitation structure, including but not limited to: static excitation, alternating current excitation, and the like, as shown in fig. 2, the excitation structure 1 excites the wire rope to saturation or near saturation. The sensor 2 shown in fig. 2 includes a magnetic flux detection sensor and a magnetic field strength detection sensor, wherein the magnetic flux detection sensor includes, but is not limited to: fluxgate sensors, induction coils, etc. As shown in fig. 3, the magnetic flux detection sensor 201 is located inside the detection device, and the magnetic flux detection includes but is not limited to: main magnetic flux, leakage magnetic flux, yoke magnetic flux, etc. Magnetic field strength detection sensors include, but are not limited to: hall sensors, magnetoresistive sensors, giant magnetoresistive sensors, tunneling magnetoresistive sensors, and the like. As shown in fig. 4, an array 202 of magnetic field strength detection sensors is distributed on the surface of the steel wire rope, and the magnetic field strength detection includes but is not limited to: three-dimensional magnetic field intensity in different directions. The signal acquisition and processing system shown in fig. 5 includes a signal acquisition unit 301, a signal preprocessing unit 302, a feature value calculation unit 303, and a defect cross-section loss quantitative analysis unit 304.
the magnetic flux detection sensor is used for acquiring a magnetic flux signal of a steel wire rope to be detected, and the magnetic field intensity detection sensor is used for acquiring a magnetic leakage signal of the steel wire rope to be detected;
The signal acquisition and processing system comprises a signal acquisition unit, a signal preprocessing unit, a characteristic value calculating unit and a defect section loss quantitative analysis unit, wherein,
the signal preprocessing unit is used for preprocessing the magnetic flux signal and the magnetic leakage signal of the steel wire rope to be detected;
The characteristic value calculating unit is used for obtaining a magnetic flux characteristic value of the detected steel wire rope defect according to the preprocessed magnetic flux signal and obtaining a magnetic leakage characteristic value of the detected steel wire rope defect according to the preprocessed magnetic leakage signal;
The defect section loss quantitative analysis unit is used for obtaining the defect width of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value;
The defect section loss quantitative analysis unit is also used for comparing the defect width of the detected steel wire rope with a preset width threshold value;
if the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected;
and if the defect width of the detected steel wire rope is smaller than the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect.
the nondestructive testing device for the steel wire rope has the beneficial effects that: the steel wire rope nondestructive testing device disclosed by the invention combines magnetic flux detection and magnetic flux leakage detection, can identify all types of defects of the tested steel wire rope, and has the advantages of higher quantitative accuracy of section loss, simple quantitative method and no need of a complex calculation method or training of a fitting sample.
the above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. a nondestructive testing method for a steel wire rope is characterized by comprising the following steps:
step S10, acquiring a magnetic flux signal of the steel wire rope to be detected through a magnetic flux detection sensor, and acquiring a magnetic leakage signal of the steel wire rope to be detected through a magnetic field intensity detection sensor;
step S20, preprocessing the magnetic flux signal and the magnetic leakage signal of the steel wire rope to be detected, obtaining the magnetic flux characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic flux signal, and obtaining the magnetic leakage characteristic value of the defect of the steel wire rope to be detected according to the preprocessed magnetic leakage signal;
step S30, obtaining the defect width of the tested steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value;
step S40, comparing the defect width of the detected steel wire rope with a preset width threshold value;
If the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected;
And if the defect width of the detected steel wire rope is smaller than the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect.
2. the nondestructive testing method for the steel wire rope according to claim 1, wherein the step of preprocessing the magnetic flux signal of the steel wire rope to be tested in step S20 includes:
carrying out outlier rejection, noise filtering and baseline elimination on the magnetic flux signal of the steel wire rope to be detected;
The step of removing the wild points of the magnetic flux signals of the detected steel wire rope comprises the following steps:
removing wild points of a magnetic flux signal Y of the steel wire rope to be detected, and setting Y (i) as an ith magnetic flux acquisition signal, so that a delta Y is | Y (i) -Y (i +1) |, wherein the delta Y is an absolute value of a difference value of the magnetic flux signals of two adjacent magnetic flux signal acquisition points; for any i, if Δ Y is less than or equal to M, M is a preset threshold, and if the point Yi exists: y (i) -Y (i-1) | > M, and Y (i) -Y (i +1) | > M, when:
Obtaining a signal Y after the wild point elimination processing1(i);
The step of carrying out noise filtering on the magnetic flux signal of the steel wire rope to be detected comprises the following steps:
and performing noise filtering on the magnetic flux signal of the steel wire rope to be detected by adopting self-adaptive filtering, wavelet transformation, smoothing filtering or empirical mode decomposition, wherein a calculation formula for performing noise filtering on the magnetic flux signal of the steel wire rope to be detected by adopting smoothing filtering is as follows:
wherein N is the number of data for averaging, and N is the total number of sampling points;
the step of eliminating the magnetic flux signal of the tested steel wire rope by the base line comprises the following steps:
Performing baseline elimination on the magnetic flux signal of the steel wire rope to be detected by adopting envelope spectrum extraction, wavelet decomposition, window averaging or empirical mode decomposition, wherein the step of performing baseline elimination on the magnetic flux signal of the steel wire rope to be detected by adopting empirical mode decomposition comprises the following steps of:
finding the signal data sequence Y2(i) fitting all the maximum value points and minimum value points to an upper envelope line and a lower envelope line of the original sequence by a cubic spline function respectively; the mean of the upper and lower envelopes is m 1; data sequence Y2(i) subtracting m1 to obtain a new sequence Y with low frequency subtracted3(i) I.e. Y3(i)=Y2(i)-m1。
3. the nondestructive testing method for the steel wire rope according to claim 2, wherein the magnetic flux characteristic value at least includes one or more of a peak-to-peak value, a width, an average value, an area and a mean square error of each defect waveform of the steel wire rope to be tested, and the step of obtaining the magnetic flux characteristic value of the defect of the steel wire rope to be tested according to the preprocessed magnetic flux signal includes:
Setting a preset threshold value, and extracting sampling points larger than the preset threshold value, wherein the preset threshold value is obtained through the test of the minimum defect of the actually tested steel wire rope;
according to the extracted sampling point position information, intercepting N points on the left and right sides of the waveform axial direction to obtain each defect waveform, wherein N is obtained through the test of the maximum defect of the actually tested steel wire rope;
And extracting the peak value, the width, the average value, the area and the mean square error of each defect waveform.
4. the nondestructive testing method for the steel wire rope according to claim 1, wherein the step of preprocessing the magnetic leakage signal of the steel wire rope to be tested in step S20 includes:
performing outlier rejection, noise filtering, baseline elimination and strand noise filtering on each path of magnetic flux leakage signals of the steel wire rope to be detected;
the step of eliminating the magnetic leakage signals of each path of the detected steel wire rope comprises the following steps:
Eliminating the wild points of each path of magnetic leakage signal XXi,jis the jth sampled value of the ith Hall sensor, so that Δ X ═ Xi,j—Xi,(j+1)the absolute value of the difference between two adjacent sampling values of the ith Hall sensor is delta X; for any i, j, if Δ X is less than or equal to F, where F is a preset threshold, then:
Obtaining a signal X after the outlier rejectioni,j
The step of carrying out noise filtering on each path of leakage magnetic signal of the tested steel wire rope comprises the following steps:
Carrying out noise filtering on each path of magnetic flux leakage signal of the steel wire rope to be tested by adopting self-adaptive filtering, or wavelet transformation, or smooth filtering, or empirical mode decomposition; the calculation formula for carrying out noise filtering on each path of magnetic leakage signal of the detected steel wire rope by adopting smooth filtering is as follows:
Wherein N is the number of data for averaging, N is the number of total sampling points, and k is the number of magnetic field intensity detection sensor paths for collecting the magnetic leakage signal of the steel wire rope to be detected;
the step of eliminating the baseline of each path of magnetic leakage signal of the tested steel wire rope comprises the following steps:
performing baseline elimination on each path of magnetic leakage signal of the tested steel wire rope by adopting envelope spectrum extraction, wavelet decomposition, window averaging or empirical mode decomposition; the step of eliminating the baseline of each path of magnetic leakage signal of the tested steel wire rope by adopting empirical mode decomposition comprises the following steps:
finding out all maximum value points and minimum value points of the original magnetic leakage signal data sequence X, and respectively fitting the maximum value points and minimum value points into an upper envelope line and a lower envelope line of the original sequence by using a cubic spline function, wherein the mean value of the upper envelope line and the lower envelope line is m 1; subtracting m1 from the original data sequence to obtain a new sequence X with low frequency subtracted1i.e. X1=X-m1;
The step of filtering the strand wave noise of each path of magnetic leakage signal of the tested steel wire rope comprises the following steps:
adopt wavelet decomposition, or empirical mode decomposition, or adaptive filtering, or the gradient method is right every way magnetic leakage signal of being surveyed wire rope carries out the spike noise filtering, wherein, adopt the gradient method right every way magnetic leakage signal of being surveyed wire rope carries out the step of spike noise filtering and includes:
Using gradient method to realize first order differentiation of image, for image X1(x, y) whose gradient at coordinate (x, y) is a two-dimensional column vector representation:
The modulus of this vector is:
And summing the multipath leakage magnetic signals to obtain a leakage magnetic sum signal X2.
5. the method according to claim 4, wherein in step S20, the leakage magnetic characteristic values of the steel wire rope to be tested at least include peak-to-peak values, widths, average values, areas and mean square deviations of each defect waveform of the steel wire rope to be tested, and the step of obtaining the leakage magnetic characteristic values of the defects of the steel wire rope to be tested according to the preprocessed leakage magnetic signals includes:
The method comprises the steps of positioning defects by adopting a local maximum value method, and setting a preset threshold value to judge whether the defects exist, wherein the preset threshold value is obtained through testing the minimum defects of the actual steel wire rope;
taking the found defect position as a central point, intercepting L points on the left and right sides of the axial direction of the waveform to obtain each defect waveform, wherein L is obtained through the test of the maximum defect of the actual steel wire rope;
and extracting the peak value, the width, the average value, the area and the mean square error of each defect waveform of the detected steel wire rope.
6. the nondestructive testing method for steel wire ropes according to claim 1, wherein the step S30 of obtaining the defect width of the steel wire rope to be tested from the magnetic flux characteristic value and the magnetic leakage characteristic value includes:
And inputting the waveform width and the waveform area of the magnetic flux characteristic value and the waveform width and the waveform area of the magnetic flux characteristic value into a defect width calculation equation or a neural network to obtain the defect width of the detected steel wire rope.
7. the method according to claim 1, wherein in step S40, if the defect width of the steel wire rope to be tested is greater than or equal to the preset width threshold, the step of obtaining the cross-sectional loss amount of the steel wire rope to be tested according to the magnetic flux characteristic value of the steel wire rope to be tested comprises:
And if the defect width of the detected steel wire rope is larger than or equal to the preset width threshold, inputting a waveform peak value, a waveform area, a waveform average value and a waveform mean square error in the magnetic flux characteristic value into a defect section loss quantity magnetic flux calculation equation or a neural network to obtain the section loss quantity of the detected steel wire rope defect.
8. the method according to claim 1, wherein in step S40, if the defect width of the steel wire rope to be tested is smaller than the preset width threshold, the step of obtaining the cross-section loss amount of the steel wire rope to be tested according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the steel wire rope to be tested comprises:
and if the defect width of the steel wire rope to be detected is smaller than the preset width threshold, inputting a waveform peak value, a waveform area, a waveform average value, a waveform mean square error and a waveform peak value, a waveform area, a waveform average value and a waveform mean square error in the magnetic flux characteristic value into a defect section loss quantity calculation equation or a neural network to obtain the section loss quantity of the steel wire rope to be detected.
9. a steel wire rope nondestructive testing device is characterized by comprising a magnetic flux detection sensor, a magnetic field intensity detection sensor and a signal acquisition and processing system, wherein,
the magnetic flux detection sensor is used for acquiring a magnetic flux signal of the steel wire rope to be detected, and the magnetic field intensity detection sensor is used for acquiring a magnetic leakage signal of the steel wire rope to be detected;
The signal acquisition and processing system comprises a signal acquisition unit, a signal preprocessing unit, a characteristic value calculating unit and a defect section loss quantitative analysis unit, wherein,
the signal preprocessing unit is used for preprocessing the magnetic flux signal and the magnetic leakage signal of the steel wire rope to be detected;
The characteristic value calculating unit is used for obtaining a magnetic flux characteristic value of the detected steel wire rope defect according to the preprocessed magnetic flux signal and obtaining a magnetic leakage characteristic value of the detected steel wire rope defect according to the preprocessed magnetic leakage signal;
The defect section loss quantitative analysis unit is used for obtaining the defect width of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value;
the defect section loss quantitative analysis unit is also used for comparing the defect width of the detected steel wire rope with a preset width threshold value;
If the defect width of the steel wire rope to be detected is larger than or equal to the preset width threshold value, obtaining the section loss of the steel wire rope to be detected according to the magnetic flux characteristic value of the defect of the steel wire rope to be detected;
And if the defect width of the detected steel wire rope is smaller than the preset width threshold, obtaining the section loss of the detected steel wire rope according to the magnetic flux characteristic value and the magnetic leakage characteristic value of the detected steel wire rope defect.
10. the nondestructive testing device for steel wire rope according to claim 9, further comprising an excitation structure for exciting the steel wire rope to be tested to saturation or near saturation.
CN201910904849.4A 2019-09-24 2019-09-24 Nondestructive testing method and device for steel wire rope Pending CN110568059A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111796174A (en) * 2020-09-09 2020-10-20 国网山东省电力公司高密市供电公司 Detection device for high-voltage cable head

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111796174A (en) * 2020-09-09 2020-10-20 国网山东省电力公司高密市供电公司 Detection device for high-voltage cable head

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