WO2024036858A1 - 一种涡流检测电路、方法、系统、存储介质及终端 - Google Patents

一种涡流检测电路、方法、系统、存储介质及终端 Download PDF

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WO2024036858A1
WO2024036858A1 PCT/CN2022/141800 CN2022141800W WO2024036858A1 WO 2024036858 A1 WO2024036858 A1 WO 2024036858A1 CN 2022141800 W CN2022141800 W CN 2022141800W WO 2024036858 A1 WO2024036858 A1 WO 2024036858A1
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differential signal
signal
differential
parameters
lift
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PCT/CN2022/141800
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English (en)
French (fr)
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马秋萍
高斌
田贵云
谌梁
罗飞
姜世强
张勇
刘磊
白宗璞
傅杨
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四川德源管道科技股份有限公司
聪明猪检测技术(成都)有限公司
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Publication of WO2024036858A1 publication Critical patent/WO2024036858A1/zh

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G01N27/9006—Details, e.g. in the structure or functioning of sensors
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/72—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables
    • G01N27/82—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws
    • G01N27/90—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents
    • G01N27/9046—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables for investigating the presence of flaws using eddy currents by analysing electrical signals

Definitions

  • the present invention relates to the technical field of eddy current non-destructive testing, and in particular to an eddy current testing circuit, method, system, storage medium and terminal.
  • Non-destructive testing technology uses physical methods to detect and evaluate possible discontinuities within the object based on the premise of not damaging the internal structure of the object being tested.
  • Eddy current is an important method among many non-destructive testing methods. Its principle is to apply alternating current at the end of the excitation coil, thereby generating an alternating magnetic field. This magnetic field interacts with the test piece to produce an alternating current in the test piece. The eddy current in the test piece generates a secondary magnetic field.
  • the detection sensor is used to detect the superimposed field of the source magnetic field and the secondary magnetic field. Through the analysis of the detection signal, the detection and identification of defects in the test piece are realized. Therefore, the structure of the coil determines the distribution and coupling relationship of the magnetic field, which is closely related to the detection performance.
  • Most of the existing eddy current array sensors design and optimize the sensor from the structure and manufacturing process of the eddy current sensor to improve the detection ability of defects.
  • the prior art CN111398413A discloses a detection sensor that detects defect information by detecting changes in the amplitude and phase of the induction coil output. It can perform defect detection under large lift-off conditions, but does not consider the impact of lift-off on the excitation coil. , when the lift-off is constantly changing, the accuracy of detection cannot be guaranteed.
  • the existing technology also proposes research on the characteristics of the transient response of the lift-off point intersection (LOI) of pulsed eddy currents, lift-off suppression methods, slope fitting methods, artificial neural networks, wavelet transform and other data based on signal processing technology Driving methods, multi/dual frequency excitation methods, sensing probe design and optimization methods, etc. Although they all have a certain immunity to lift-off, defect information is still easily obscured by fluctuations under random conditions such as railway or pipeline inspections or high lift-off noise, and requires parameter adjustment settings, system modulation and demodulation. Complex and difficult to implement engineering applications.
  • LOI lift-off point intersection
  • the purpose of the present invention is to suppress lift-off interference and enhance defect detection capabilities. It proposes an eddy current detection circuit, method, system, storage medium and terminal, which uses a differential bridge and a transformer-type conditioning circuit structure to form a dual-channel differential probe. Based on the equivalent circuit model, the relationship between the amplitude, phase parameters and lift-off generated by the dual-channel differential probe under the alternating magnetic field is constructed, and a method for multi-parameter signal fusion is proposed.
  • an eddy current detection circuit including:
  • the probe includes an excitation unit and an induction unit.
  • the excitation unit forms a differential bridge for receiving the excitation signal and outputting a first differential signal.
  • the induction unit is coupled with the excitation unit to form a transformer conditioning circuit and outputs a second differential signal. Signal;
  • a differential signal processing unit configured to receive the first differential signal and the second differential signal, and analyze the relationship between the parameters of the first differential signal, the parameters of the second differential signal and lift-off under the alternating magnetic field, And the parameters of the first differential signal and the parameters of the second differential signal are fused to eliminate the influence of lift-off on the signal.
  • the excitation unit is composed of a plurality of excitation coils arranged side by side in a row
  • the induction unit is composed of a plurality of induction coils placed in one-to-one correspondence with the excitation coils, wherein the coil windings of the induction coils and the excitation coils are Row direction is opposite;
  • the input end of the excitation coil is connected to the output end of the signal generator, multiple excitation coils are connected in parallel, and the output end of the excitation coil is connected with a capacitor or a resistor; the output ends of two adjacent excitation coils are both Connected to a first differential amplifier; the output terminals of two adjacent induction coils are connected to a second differential amplifier.
  • the excitation coil and the induction coil are placed side by side, two adjacent excitation coils serve as two arms of the AC bridge, and the corresponding two capacitors or resistors are connected to the remaining two arms of the AC bridge. .
  • an eddy current detection method including the following steps:
  • an eddy current detection method the S2 includes:
  • the relationship between the amplitude of the first differential signal, the phase of the first differential signal, the amplitude of the second differential signal, the phase of the second differential signal and the lift-off is analyzed respectively.
  • an eddy current detection method the S3 includes:
  • the fused amplitude is fused with the linearly processed phase parameters to obtain the final detection signal.
  • an eddy current detection method the influence of lift-off on the two differential signal amplitude parameters is negatively correlated.
  • an eddy current detection method linearly processing the phase parameters of the first differential signal and/or the second differential signal includes:
  • a differential operation is performed using the phase parameters of the first differential signal and/or the second differential signal to remove nonlinearity.
  • an eddy current detection system is provided, and the system includes:
  • a differential signal acquisition module used to acquire the first differential signal and the second differential signal output by the probe when the lift-off changes, wherein the first differential signal is output by the excitation unit of the probe, and the second differential signal The signal is output by the sensing unit of the probe;
  • a parameter calculation module used to analyze the relationship between the parameters of the first differential signal, the parameters of the second differential signal and lift-off under an alternating magnetic field
  • a multi-parameter fusion module is used to fuse the parameters of the first differential signal with the parameters of the second differential signal to eliminate the impact of lift-off on the signal.
  • a storage medium is provided with computer instructions stored thereon, and when the computer instructions run, the eddy current testing method is executed.
  • a terminal including a memory and a processor.
  • the memory stores computer instructions that can be executed on the processor.
  • the processor executes the computer instructions, the eddy current detection method is executed.
  • the excitation unit of the probe forms a differential bridge, and the induction unit and the excitation unit are coupled to form a transformer conditioning circuit.
  • the entire probe adopts a combination of a differential bridge and a transformer conditioning circuit, in which the induction unit The first differential signal is output, and the excitation unit outputs the second differential signal, forming a dual-channel differential output circuit.
  • the dual-channel differential output has high detection capabilities for defects when the lift-off changes.
  • the differential signal processing unit obtains the first differential signal and the second differential signal generated by the induction unit and the excitation unit respectively.
  • the dual-channel differential output has high detection capability for defects when the lift-off changes at high levels; At the same time, the signal parameters of the two differential signals are fused. Since the lift-off change will affect the first differential signal and the second differential signal at the same time, by mathematically changing the two signals, the effect of the lift-off on the two signals is eliminated.
  • the joint influence of can suppress lift-off, improve defect detection capabilities when lift-off changes, and does not require parameter adjustment and other operations, making it simple and practical.
  • the present invention fuses the amplitude of the first differential signal with the amplitude of the second differential signal.
  • the change in amplitude after fusion is only related to the coupling coefficient of the induction coil and the eddy current, and can reflect more information about the test piece to improve detection capabilities; perform linear processing on the phase parameters of the first differential signal and the second differential signal, and fuse them with the fused amplitudes.
  • the fusion of multiple parameters can enhance the defect information. .
  • the output end of the excitation coil of the present invention is connected to a first differential amplifier, and the output end of the induction coil is connected to a second differential amplifier.
  • the differential amplifier can be used to differentiate the signal in the input amplifier to suppress the common mode. Signals such as (temperature, humidity, etc.) amplify the differential mode signal caused by defects and increase the detection sensitivity of defects.
  • the excitation coil of the present invention and the induction coil are placed side by side.
  • the induction coil receives less magnetic flux generated by the excitation coil, so the background signal is small and more relevant test pieces can be received.
  • the information can have a better lift-off suppression effect than placing it up and down.
  • the attenuation speed of eddy current in the specimen is negatively related to the coil radius.
  • the excitation coil can be regarded as the center of the circle, and the distance from the excitation coil to the induction coil is regarded as the radius. Therefore, the larger the radius, the slower the attenuation speed of the eddy current. This makes it theoretically possible to detect deeper defects.
  • Figure 1 is a schematic structural diagram of the eddy current detection probe shown in the present invention.
  • Figure 2 is a schematic diagram showing the structure of the excitation coil and the connection of the differential bridge according to the present invention
  • FIG. 3 is a schematic connection diagram of the equivalent transformer shown in the present invention.
  • Figure 4 shows the probe structure corresponding to more than two sets of excitation coils according to the present invention
  • Figure 5 is a schematic structural diagram of a probe in which one set of excitation coils corresponds to two sets of induction coils according to the present invention
  • Figure 6 is a schematic diagram of the operation of the eddy current probe based on the differential bridge and transformer conditioning circuit shown in the present invention
  • Figure 7 is a circuit diagram corresponding to the first differential signal during modeling according to the present invention.
  • Figure 8 is an equivalent circuit diagram corresponding to the first differential signal shown in the present invention.
  • Figure 9 is a circuit diagram corresponding to the second differential signal during modeling according to the present invention.
  • Figure 10 is an equivalent circuit diagram corresponding to the second differential signal shown in the present invention.
  • Figure 11 is a graph showing the amplitude change curve of the bridge output when the lift-off increases according to the present invention.
  • Figure 12 is a graph showing the amplitude change curve of the transformer output when the lift-off increases according to the present invention.
  • Figure 13 is a phase change curve diagram of the bridge output when the lift-off increases according to the present invention.
  • Figure 14 is a phase change curve diagram of the transformer output when the lift-off increases according to the present invention.
  • Figure 15 shows the processing results of the lift-off change curve using the fusion model according to the present invention
  • Figure 16 shows the detection results and signal fusion results of different defects when the lift-off gradually increases according to the present invention
  • Figure 17 shows the detection results and signal fusion results of cracks along the weld seam according to the present invention.
  • Figure 18 shows the pipeline defect detection results and signal fusion results of the present invention.
  • connection should be understood in a broad sense.
  • connection or integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two components.
  • connection or integral connection
  • connection, or integral connection can be a mechanical connection or an electrical connection
  • it can be a direct connection or an indirect connection through an intermediate medium
  • it can be an internal connection between two components.
  • specific meanings of the above terms in the present invention can be understood on a case-by-case basis.
  • This invention mainly uses a combination of a differential bridge and a transformer conditioning circuit to perform multi-parameter measurement of amplitude and phase.
  • the dual-channel differential output has high detection capabilities for defects when the lift-off changes are high, and at the same time, it uses the measured
  • a multi-parameter fusion model is proposed, which can suppress lift-off and improve defect detection capabilities when lift-off changes. It does not require parameter adjustment and other operations, making it simple and practical.
  • conditioning circuits are also important in parameter measurement of non-destructive testing and evaluation technology. For example, low-frequency components are detected in pulsed eddy currents through inductive coupling methods, and magnetic fields or magnetic field change rates are measured through magnetic sensors (such as Hall, AMR, GMR, TMR) or induction coils. Peak amplitude, zero-crossing time, phase, peak arrival time, rise time, etc. reflect the magnetic flux generated by the eddy current, which carries the information of the sample. From the perspective of power transmission, magnetic coupling has the largest energy transmission and maintains constant efficiency within a certain range. It uses swept frequency excitation with multiple resonant frequencies to obtain different defect information and parameter acquisition.
  • the signal conditioning circuits in traditional eddy current detection are resonant circuits, bridge circuits, and inductive coupling transformers.
  • the classic resonant circuit contains a parallel inductor and capacitor, where the peak voltage occurs at a maximum at the resonant frequency. When a defect is present, the frequency change of the resonant frequency will cause a sharp drop in the voltage.
  • the bridge circuit uses inductors and resistors as bridge arms to convert changes in impedance into voltage.
  • the inductive coupling system refers to a transformer in which two or more coils are coupled to each other. However, these characteristics vary due to different coupling parameters (such as discontinuities, cracks or peeling, etc.). Therefore, the design and selection of appropriate sensing probes and conditioning circuits are particularly critical in eddy current testing.
  • an eddy current detection circuit including:
  • the probe includes an excitation unit and an induction unit.
  • the excitation unit forms a differential bridge for receiving the excitation signal and outputting a first differential signal, which is the output signal U o1 of the bridge in the figure.
  • the induction unit is coupled to the excitation unit. Form a transformer conditioning circuit and output the second differential signal, that is, the output signal U o2 of the transformer;
  • a differential signal processing unit used to receive the first differential signal U o1 and the second differential signal U o2 , and analyze the parameters of the first differential signal U o1 and the second differential signal U o2 under the alternating magnetic field.
  • the relationship between the parameters and the lift-off, and the parameters of the first differential signal U o1 and the parameters of the second differential signal U o2 are fused to eliminate the influence of the lift-off on the signal.
  • the excitation unit is composed of a plurality of excitation coils arranged in a row
  • the induction unit is composed of a plurality of induction coils placed in one-to-one correspondence with the excitation coils, wherein the winding directions of the induction coils and the excitation coils are opposite.
  • the eddy current detection circuit also includes a first differential amplifier and a second differential amplifier.
  • the input end of the excitation coil is connected to the output end of the signal generator.
  • a plurality of the excitation coils are connected in parallel.
  • the output end is connected with a capacitor or a resistor; the output ends of two adjacent excitation coils are connected to a first differential amplifier, and the first differential amplifier is used to amplify and output the first differential signal U o1 ;
  • the output terminal of each of the induction coils is connected to a second differential amplifier, and the second differential amplifier is used to amplify and output the second differential signal U o2 .
  • the probe structure consists of two sets of horizontally placed flat square spiral coils.
  • Each set of coils contains two square coils of equal size, one of which is an excitation coil and the other One group is an induction coil, and the excitation coil is connected in parallel.
  • the winding direction of the induction coil is opposite to that of the excitation coil.
  • the excitation coil and the induction coil are placed side by side on the same plane.
  • the winding method of the coil determines the two groups of coils.
  • the difference of the conditioning circuit is a combination of differential bridge and transformer conditioning circuit. It should be noted that in other embodiments, the excitation coil and the induction coil can be placed vertically, and the actual number of excitation coils required can be an even number greater than 2.
  • the excitation coil and the induction coil are placed side by side on the same plane.
  • the total magnetic flux received by the induction coil is the sum of the magnetic field generated by the excitation coil and the magnetic field generated by the eddy current on the specimen.
  • the magnetic flux generated by the excitation coil is There is a lot of magnetic flux directly penetrating into the induction coil (direct coupling between coils), so the background signal is strong.
  • the coupling vector distance between the coils is large and the coupling coefficient is small. It receives less magnetic flux generated by the excitation coil, so the background signal is small, it can receive more information about the specimen, and it can have better lift-off suppression effect than placing it up and down.
  • the attenuation speed of eddy current in the specimen is negatively related to the coil radius.
  • the excitation coil can be regarded as the center of the circle, and the distance from the excitation coil to the induction coil is regarded as the radius. Therefore, the larger the radius, the slower the attenuation speed of the eddy current. This makes it theoretically possible to detect deeper defects.
  • a differential bridge is provided.
  • the excitation unit includes two excitation coils. Two adjacent excitation coils serve as two arms of the AC bridge. The corresponding two capacitors or resistors are connected to On the remaining two arms of the AC bridge, specifically, as shown in Figure 2, L 1 and L 2 of the excitation coil serve as the two arms of the AC bridge, and the remaining two arms are two capacitors with the same capacitance C, Therefore, the differential voltage of the two capacitors is the output of the AC bridge, which we call U o1 .
  • the excitation coil consists of two coils with the same size and parameters placed horizontally. The common ends of the two coils are connected in parallel to the signal generator. The remaining ends are connected in series with capacitors of equal capacitance. The other ends of the two capacitors are connected in series. One end is grounded. The voltage across the capacitor passes into the differential amplifier, so the current direction of the entire excitation coil is the same, and the two coils and the two capacitors form a bridge connection.
  • the induction coil is composed of two coils connected in series.
  • the two coils are equal in size and have the same wire diameter.
  • One end of each is connected to a differential amplifier for increasing The ability to detect defects. Therefore, the two excitation coils are regarded as a whole, and the differential induction coil is regarded as a whole.
  • the excitation coil L 1 and the excitation coil L 2 constitute the primary side of the transformer
  • the induction coil L 3 and the induction coil L 4 constitutes the secondary side of the transformer. Therefore, we can obtain the differential voltage U o2 from the differential induction coil consisting of induction coil L 3 and induction coil L 4 .
  • the parallel input end of the excitation coil is connected to the signal generator, and the output end of each excitation coil is connected in series with a capacitor and connected to the first differential amplifier.
  • the first differential amplifier It is used to output the first differential signal U o1 ;
  • the output end of the induction coil is connected to the second differential amplifier, and the second differential amplifier is used to output the second differential signal U o2 .
  • the signal generator generates a sine wave signal of a specific frequency, which is injected into the power amplifier to increase the load carrying capacity of the probe.
  • the excitation coil receives the amplified AC signal.
  • the probe interacts with the conductor under the alternating electromagnetic field to generate eddy current.
  • the excitation coil outputs the first differential signal U o1 through the first differential amplifier.
  • the induction coil interacts with the excitation coil and the conductor under test.
  • the second differential signal U o2 is output, and both signals are output to the signal conditioning circuit, further collected by the data acquisition unit, and finally passed through the differential signal processing unit for subsequent analysis.
  • the acquisition circuit converts the changed amplitude and phase. Carry out data collection.
  • the probe of the present invention adopts a combination of a differential bridge and a transformer conditioning circuit to perform multi-parameter measurements of amplitude and phase on the output of the excitation unit and the induction unit respectively.
  • the dual-channel differential output has a high sensitivity to defects when the lift-off changes are high. Detection capability, simultaneously fuses the signal parameters of two differential signals, can suppress lift-off, and does not require parameter adjustment and other operations, making it simple and practical.
  • excitation unit includes multiple groups of excitation coils
  • the corresponding induction unit includes multiple groups of induction coils.
  • the working principle of each group of coils is as follows: Embodiment of the coil in Figure 1. Among them, all coils are located in the same horizontal plane. Perform fusion measurements of more sets of differential output signal parameters to more accurately detect defects.
  • one set of excitation coils can correspond to two sets of induction coils, where all coils are located in the same horizontal plane, and the two sets of induction coils are located on both sides of the excitation coil.
  • update The fusion measurement of multiple sets of differential output signal parameters can more accurately detect defects. It should be noted that other arrays based on this probe or changes based on the same principle are still within the protection scope of this application.
  • an eddy current detection method including the following steps:
  • the first differential signal U o1 is output by the excitation unit of the probe, and the second differential signal U o2 is output by the excitation unit of the probe.
  • the signal U o2 is output by the sensing unit of the probe;
  • the S2 includes:
  • the S3 includes:
  • the fused amplitude is fused with the linearly processed phase parameters to obtain the final detection signal.
  • the defects of the test piece are analyzed based on the final detection signal.
  • the output of the differential bridge is a differential signal, which is used to amplify external input differential signals that may destroy the balance of the bridge and suppress common-mode signals such as (temperature, etc.), when the lift-off changes, there is no amount that destroys the balance. Therefore, as long as the lift-off changes, the output of the bridge is the result of the lift-off change. If the defect is located under the single coil bridge arm, the balance of the bridge will be broken, and the differential mode output will be the defect response signal.
  • the transformer induction coil it not only receives the magnetic field directly coupled by the excitation coil, but also receives the reflected magnetic field of the eddy current on the measured conductor (the magnetic field of the induction coil itself and the measured conductor can be ignored). From the results, the difference The output of the moving coil is the result of the difference between the two, and the differential coil (i.e. L 3 , L 4 ) is also regarded as a whole L r .
  • obtaining the first differential signal U o1 and the second differential signal U o2 respectively includes:
  • the measured conductor is equivalent to a coil with inductance and resistance, equivalent circuits corresponding to the first differential signal U o1 and the second differential signal U o2 are established respectively, and modeling is performed based on the equivalent circuit.
  • the measured conductor is equivalent to a coil with inductance L t and resistance R t , which can be modeled according to Kirchhoff's law. Thus, modeling the two signals under lift-off changes based on the equivalent circuit can be obtained:
  • R v and L v refer to the equivalent resistance and equivalent inductance formed by two parallel excitation coils under the action of magnetic field.
  • I v is the equivalent current flowing into the excitation coil
  • U p refers to the voltage of the sinusoidal signal flowing into the coil.
  • f refers to the frequency of the incoming excitation signal
  • I e is the eddy current generated on the conductor.
  • M vt is the mutual inductance between the excitation coil and the conductor under test and is related to the lifting distance x.
  • k vt is the coupling coefficient between the excitation coil and the conductor under test.
  • C s is the capacitance of the capacitor in series with the coil, and then we can get the amplitude of the change in U o1
  • k rt (x) refers to the mutual inductance coefficient between the induction coil and the conductor under test. This coefficient is also related to the lifting distance x.
  • Phase change of the second stage differential transformer output for:
  • of the second differential signal includes:
  • the relationship between the amplitude of the first differential signal U o1 and the amplitude of the second differential signal U o2 is utilized to eliminate the common influence of lift-off on the amplitude parameters of the two differential signals. It can be found from the model that lift-off has a common impact on the amplitude parameters of the two output channels, namely k vt , and their impacts are negatively correlated. Therefore, we propose to use their amplitude relationship to eliminate the influence of k vt :
  • the linear processing of the phase parameters of the first differential signal U o1 and/or the second differential signal U o2 includes:
  • phase parameters of the first differential signal U o1 and/or the second differential signal U o2 are used to perform differential operations to remove their nonlinearity. From equation (10), it can be seen that the change in amplitude after fusion is only related to the coupling coefficient of the induction coil and eddy current, and this quantity reflects more information about the specimen. Equation (7) reflects that the phase of the signal has nothing to do with the lift-off, but there is nonlinearity. Therefore, we can use the differential operation of the phase to remove its nonlinearity and fuse it with the existing amplitude signal to enhance the Defect information.
  • the final fusion detection signal used for specimen defect detection is:
  • This method uses a combination of a differential bridge and a transformer conditioning circuit to perform multi-parameter measurements of amplitude and phase.
  • the dual-channel differential output has high detection capabilities for defects when the lift-off changes at high levels; at the same time, the measured multi-parameters are used.
  • the parameters are proposed for fusion calculation, which can suppress lift-off and improve defect detection capabilities when lift-off changes. It does not require parameter adjustment and other operations, making it simple and practical.
  • an eddy current detection system which system includes:
  • a differential signal acquisition module used to acquire the first differential signal U o1 and the second differential signal U o2 output by the probe when the lift-off changes, where the first differential signal U o1 is generated by the excitation unit of the probe. Output, the second differential signal U o2 is output by the sensing unit of the probe;
  • a parameter calculation module used to analyze the relationship between the parameters of the first differential signal U o1 , the parameters of the second differential signal U o2 and lift-off under an alternating magnetic field;
  • the multi-parameter fusion module is used to fuse the parameters of the first differential signal U o1 with the parameters of the second differential signal U o2 to eliminate the influence of lift-off on the signal.
  • the multi-parameter fusion module is used to fuse the amplitude of the first differential signal U o1 and the amplitude of the second differential signal U o2 , and combine the first differential signal U o1 and, /or perform linear processing on the phase parameter of the second differential signal U o2 ; and fuse the fused amplitude with the linearly processed phase parameter to obtain the final detection signal;
  • a defect analysis module is used to analyze the defects of the test piece according to the final detection signal.
  • the multi-parameter fusion module uses the relationship between the amplitude of the first differential signal U o1 and the amplitude of the second differential signal U o2 to eliminate the joint influence of the lift-off on the amplitude parameters of the two differential signals.
  • the change after value fusion is only related to the coupling coefficient of the induction coil and the eddy current, which reflects more information about the specimen.
  • the phase parameters of the first differential signal U o1 and/or the second differential signal U o2 are used to perform differential operations to remove their nonlinearity.
  • the defect information can be enhanced by using the differential operation of the phase to remove its nonlinearity and fuse it with the existing amplitude signal.
  • the detection effect and detection method of the probe are verified by examples. Specifically, the changes in the two output signals when the detection lift-off increases are first verified, as shown in Figures 11 to 14 , in the process of lifting the probe upward at a point, the changes in the output signals of the two outputs are different. As shown in Figure 11, for the output of the bridge, as the lifting distance increases, the amplitude of the output signal first It increases and then decreases, as shown in Figure 12. For the output of the transformer, under the same conditions, the amplitude of the output signal first decreases and then increases, thus reflecting the parameters measured by the two outputs for the same change. are different, which also lays the foundation for the proposal of the lift-off fusion suppression method.
  • Embodiment 2 has the same inventive concept as Embodiment 2. Based on Embodiment 2, a storage medium is provided, on which computer instructions are stored, and the eddy current detection method is executed when the computer instructions are run.
  • the technical solution of this embodiment is essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, It includes several instructions to cause a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present invention.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program code. .
  • Embodiment 1 has the same inventive concept as Embodiment 1, and provides a terminal, including a memory and a processor.
  • the memory stores computer instructions that can be run on the processor.
  • the processor runs the computer instructions, it executes the eddy current detection method. .
  • the processor may be a single-core or multi-core central processing unit or a specific integrated circuit, or one or more integrated circuits configured to implement the invention.
  • Embodiments of the subject matter and functional operations described in this specification may be implemented in tangibly embodied computer software or firmware, computer hardware including the structures disclosed in this specification and their structural equivalents, or one or more of them. a combination of.
  • Embodiments of the subject matter described in this specification may be implemented as one or more computer programs, i.e., one or more of computer program instructions encoded on a tangible non-transitory program carrier for execution by, or to control the operation of, data processing apparatus. Multiple modules.
  • the program instructions may be encoded on an artificially generated propagated signal, such as a machine-generated electrical, optical, or electromagnetic signal, which signal is generated to encode and transmit the information to a suitable receiver device for transmission by the data
  • the processing device executes.
  • the processes and logic flows described in this specification may be performed by one or more programmable computers executing one or more computer programs to perform corresponding functions by operating on input data and generating output.
  • the processes and logic flows may also be performed by dedicated logic circuits, such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the device may also be implemented as a dedicated logic circuit.
  • FPGA Field Programmable Gate Array
  • ASIC Application Specific Integrated Circuit
  • processors suitable for executing the computer program include, for example, general and/or special purpose microprocessors, or any other type of central processing unit.
  • the central processing unit will receive instructions and data from read-only memory and/or random access memory.
  • the basic components of a computer include a central processing unit for implementing or executing instructions and one or more memory devices for storing instructions and data.
  • the computer will also include one or more mass storage devices for storing data, such as magnetic, magneto-optical or optical disks, or the like, or the computer will be operably coupled to such mass storage device to receive data therefrom or to It transmits data, or both.
  • the computer is not required to have such a device.
  • the computer may be embedded in another device, such as a mobile phone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a global positioning system (GPS) receiver, or a universal serial bus (USB) ) flash drives for portable storage devices, to name a few.
  • PDA personal digital assistant
  • GPS global positioning system
  • USB universal serial bus

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Abstract

本发明公开了一种涡流检测电路、方法、系统、存储介质及终端，属于涡流无损检测技术领域，主要利用差动电桥和变压器调理电路结合形成双路差分探头，并利用第一差动信号和第二差动信号在各自的交变磁场下产生的信号参数，分析在交变磁场下各自产生的幅值、相位参数和提离的关系，进行多参数信号融合，可以抑制提离，双路差动输出在高提离变化时，对缺陷具有高检出能力。

Description

一种涡流检测电路、方法、系统、存储介质及终端 技术领域
本发明涉及涡流无损检测技术领域，尤其涉及一种涡流检测电路、方法、系统、存储介质及终端。
背景技术
无损检测技术是以不破坏被测物体内部结构为前提，使用物理的方法对物体内部可能存在的不连续性进行检测和评估。电涡流是众多无损检测方法类别中的一类重要方法，其原理是在激励线圈端施加交变的电流，从而产生交变的磁场，该磁场与被测试件相互作用，在试件中产生交变的涡流，试件中的涡流产生次生磁场，利用检测传感器对源磁场和次生磁场的叠加场检测，通过对检测信号的分析，实现对试件中缺陷的检测识别。因此线圈的结构决定了磁场的分布和耦合关系，与检测性能息息相关。现有的涡流阵列传感器，大多是从涡流传感器的结构和制作工艺对传感器进行设计和优化，以提高对缺陷的检测能力。
而在进行涡流检测时，传感探头与管壁之间的非接触检测存在提离距离且检测工况常常具有的随机性使得提离并非恒定(如管道检测、钢轨检测)。因此，随着提离的变化，该距离改变了探头与金属导体形成电路的互感，这将会导致提离波形信号被误认为缺陷信号，从而影响缺陷存在与否的定性判断。此外，原有的缺陷信号会在提离的干扰下受到影响，导致幅值、相位等参数的变化，这将为缺陷的定量分析带来挑战，无法准确量化缺陷的尺寸与损伤状态评估。故提离问题是涡流检测中的关键问题，须对其进行干扰效应进行抑制，提高检 测准确性和可靠性。为了消除提离噪声增加对缺陷的检测能力，目前已有相关学者开展了多项研究工作。现有技术CN111398413A中公开了一种检测传感器，其通过检测感应线圈输出的幅值和相位的变化来检测缺陷信息，可以在大提离下进行缺陷检测，但是未考虑提离对激励线圈的影响，在提离不断变化的情况下，无法保证检测的准确度。
此外，现有技术还提出了对脉冲涡流的提离点交叉点(LOI)瞬态响应的特性研究，基于信号处理技术进行提离抑制方法，斜率拟合方法，人工神经网络、小波变换等数据驱动方法，多/双频激励等方法，传感探头的设计与优化方法等。虽然它们均对提离具有一定的免疫效果，但是缺陷信息在铁路或管道检查等随机条件下的波动中或者高提离噪声中依然容易被掩盖，且需要调参设置，系统的调制与解调复杂，难以实现工程应用。
发明内容
本发明的目的在于抑制提离的干扰，增强缺陷的检测能力，提出一种涡流检测电路、方法、系统、存储介质及终端，利用差动电桥与变压器式调理电路结构构成双路差分探头，基于等效电路模型构建双路差分探头在交变磁场下各自产生的幅值、相位参数和提离的关系，并提出了进行多参数信号融合的方法。
本发明的目的是通过以下技术方案来实现的：
在一个方案中，提供一种涡流检测电路，包括：
探头，包括激励单元和感应单元，所述激励单元形成差动电桥用于接收激励信号并输出第一差动信号，所述感应单元与激励单元进行耦合形成变压器调理电路并输出第二差动信号；
差动信号处理单元，用于接收所述第一差动信号、第二差动信号，分析在 交变磁场下第一差动信号的参数、第二差动信号的参数与提离的关系，并将第一差动信号的参数与第二差动信号的参数进行融合，消去提离对信号的影响。
进一步的方案中，激励单元由多个并排成一列的激励线圈组成，感应单元由多个与所述激励线圈一一对应放置的感应线圈组成，其中，所述感应线圈和激励线圈的线圈绕行方向相反；
所述激励线圈的输入端与所述信号发生器的输出端连接，多个所述激励线圈并联，所述激励线圈的输出端连接有电容器或电阻器；相邻两个激励线圈的输出端均连接至一个第一差动放大器；相邻两个所述感应线圈的输出端接至一个第二差动放大器。
进一步的方案中，所述激励线圈和所述感应线圈并排放置，相邻两个所述激励线圈作为交流电桥的两臂，将对应的两个电容器或电阻器连接在交流电桥的其余两臂上。
在另一个方案中，提供一种涡流检测方法，包括以下步骤：
S1、在提离变化的情况下，获取探头输出的第一差动信号以及第二差动信号，其中，第一差动信号由探头的激励单元输出，第二差动信号由探头的感应单元输出；
S2、分析在交变磁场下第一差动信号的参数、第二差动信号的参数与提离的关系；
S3、将第一差动信号的参数与第二差动信号的参数进行融合，消去提离对信号的影响。
进一步的方案中，一种涡流检测方法，所述S2包括：
计算所述第一差动信号的幅值和相位参数，计算所述第二差动信号的幅值和相位参数；
分别分析所述第一差动信号的幅值、第一差动信号的相位、第二差动信号的幅值、第二差动信号的相位与提离的关系。
进一步的方案中，一种涡流检测方法，所述S3包括：
将所述第一差动信号的幅值与所述第二差动信号的幅值进行融合；
对所述第一差动信号和、/或第二差动信号的相位参数进行线性处理；
将融合后的幅值与线性处理后的相位参数进行融合，得到最终的检测信号。
作为一优选项，一种涡流检测方法，提离对两个差动信号幅值参数的影响成负相关。
进一步的方案中，一种涡流检测方法，所述对所述第一差动信号和、/或第二差动信号的相位参数进行线性处理，包括：
利用所述第一差动信号和、/或第二差动信号的相位参数进行微分操作，去除其非线性性。
在另一个方案中，基于与所述检测方法相同的发明构思，提供一种涡流检测系统，所述系统包括：
差动信号获取模块，用于在提离变化的情况下，获取探头输出的第一差动信号以及第二差动信号，其中，第一差动信号由探头的激励单元输出，第二差动信号由探头的感应单元输出；
参数计算模块，用于分析在交变磁场下第一差动信号的参数、第二差动信号的参数与提离的关系；
多参数融合模块，用于将第一差动信号的参数与第二差动信号的参数进行融合，消去提离对信号的影响。
在另一个方案中，提供一种存储介质，其上存储有计算机指令，所述计算机指令运行时执行所述涡流检测方法。
在另一个方案中，提供一种终端，包括存储器和处理器，存储器上存储有可在处理器上运行的计算机指令，所述处理器运行计算机指令时执行所述涡流检测方法。需要进一步说明的是，上述各选项对应的技术特征在不冲突的情况下可以相互组合或替换构成新的技术方案。
与现有技术相比，本发明有益效果是：
(1)本发明的检测电路中探头的激励单元形成差动电桥，感应单元与激励单元进行耦合形成变压器调理电路，整个探头采用差动电桥和变压器调理电路组合的方式，其中，感应单元输出第一差动信号，激励单元输出第二差动信号，形成双路差动输出电路，双路差动输出在高提离变化时，对缺陷具有高检出能力提离变化时，在交变磁场下，差动信号处理单元获取感应单元与激励单元各自产生的第一差动信号、第二差动信号，双路差动输出在高提离变化时，对缺陷具有高检出能力；同时将两种差动信号的信号参数进行融合，由于提离变化会同时对第一差动信号、第二差动信号产生影响，通过将两种信号进行数学变化，消去提离对两种信号的共同影响，可以抑制提离，在提离变化时可以提高缺陷检测能力，且不需要调参等操作，简单实用。
(2)本发明将第一差动信号的幅值与所述第二差动信号的幅值进行融合，幅值融合后的变化量只与感应线圈和涡流的耦合系数有关，能够反映更多的有关试件的信息，提高检测能力；对所述第一差动信号和第二差动信号的相位参数进行线性处理，并与融合后的幅值融合，多参数的融合更能增强缺陷信息。
(3)本发明激励线圈的输出端连接有第一差动放大器，感应线圈的输出端连接有第二差动放大器，使用差动放大器可以对输入放大器中的信号进行差分，起到抑制共模信号如(温度、湿度等)，放大由缺陷引起的差模信号，增加缺陷的检测灵敏度。
(4)本发明激励线圈和所述感应线圈并排放置，采用该种放置方式时，感应线圈中接收到的由激励线圈产生的磁通少，因此背景信号小，能够接收更多的有关试件的信息，能够比上下放置具有更好的提离抑制效果。其次，涡流在试件中的衰减速度与线圈半径呈负相关，水平放置时可将激励线圈视为圆心，激励线圈到感应线圈的距离视为半径，因此半径大，涡流的衰减速度更慢，从而理论上能够检测更深的缺陷。
附图说明
下面结合附图对本发明的具体实施方式作进一步详细的说明，此处所说明的附图用来提供对本申请的进一步理解，构成本申请的一部分，在这些附图中使用相同的参考标号来表示相同或相似的部分，本申请的示意性实施例及其说明用于解释本申请，并不构成对本申请的不当限定。
图1为本发明示出的涡流检测探头的结构示意图；
图2为本发明示出的激励线圈的结构和差动电桥的连接示意图；
图3为本发明示出的等效变压器的连接示意图；
图4为本发明示出的2组以上激励线圈对应的探头结构；
图5为本发明示出的一组激励线圈对应两组感应线圈的探头结构示意图；
图6为本发明示出的基于差动电桥和变压器调理电路的涡流探头工作示意图；
图7为本发明示出的建模时第一差动信号对应的电路图；
图8为本发明示出的第一差动信号对应的等效电路图；
图9为本发明示出的建模时第二差动信号对应的电路图；
图10为本发明示出的第二差动信号对应的等效电路图；
图11为本发明示出的电桥输出在提离增大时幅值变化曲线图；
图12为本发明示出的变压器输出在提离增大时幅值变化曲线图；
图13为本发明示出的电桥输出在提离增大时相位变化曲线图；
图14为本发明示出的变压器输出在提离增大时相位变化曲线图；
图15为本发明示出的采用融合模型对提离变化曲线的处理结果；
图16为本发明示出的在提离逐渐增大时对不同缺陷的检测结果和信号融合结果；
图17为本发明示出的对沿焊缝裂纹检测结果和信号融合结果；
图18为本发明示出的对管道缺陷检测结果和信号融合结果。
具体实施方式
下面结合附图对本发明的技术方案进行清楚、完整地描述，显然，所描述的实施例是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
在本发明的描述中，需要说明的是，属于“中心”、“上”、“下”、“左”、“右”、“竖直”、“水平”、“内”、“外”等指示的方向或位置关系为基于附图所述的方向或位置关系，仅是为了便于描述本发明和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本发明的限制。此外，属于“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性。
在本发明的描述中，需要说明的是，除非另有明确的规定和限定，属于“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以具体情况理解上述术语在本发明中的具体含义。
此外，下面所描述的本发明不同实施方式中所涉及的技术特征只要彼此之 间未构成冲突就可以相互结合。
本发明主要通过采用差动电桥和变压器调理电路组合的方式，进行幅值相位的多参数测量，双路差动输出在高提离变化时，对缺陷具有高检出能力，同时利用所测量的多参数提出了融合模型，可以抑制提离，在提离变化时可以提高缺陷检测能力，且不需要调参等操作，简单实用。
实施例1
因为物理信息可以转换为电路参数，所以不同的信号调理电路可以测量不同的物理参数，故调理电路在无损检测和评价技术的参数测量中同样具有重要。例如，通过感应耦合方法在脉冲涡流中检测低频成分，通过磁传感器(如Hall、AMR、GMR、TMR)或感应线圈测量磁场或磁场变化率。峰值振幅、过零时间、相位、峰值到达时间和上升时间等反映了涡流产生的磁通量，该磁通量携带了样本的信息。从功率传输的角度来看，磁耦合具有最大的能量传输，并在一定范围内保持恒定的效率，它使用具有多个共振频率的扫频激励来获得不同的缺陷信息和参数获取。此外，通常提取阻抗的实部和虚部，在这种效果下，传统涡流检测中的信号调理电路为谐振电路、电桥电路以及电感耦合变压器。经典的谐振电路包含一个并联的电感和电容器，其中峰值电压在谐振频率下出现最大值，当有缺陷存在时，谐振频率的频率变化将引起的电压急剧下降。而电桥电路使用电感器和电阻作为桥臂，将阻抗的变化转换为电压。而电感耦合系统是指两个或多个线圈进行相互耦合的变压器。但是这些特征因耦合参数的不同(如不连续性、裂纹或剥离等)而变化。因此设计和选择合适的传感探头和调理电路在涡流检测中尤为关键。
在一示例性实施例中，提供一种涡流检测电路，包括：
探头，包括激励单元和感应单元，所述激励单元形成差动电桥用于接收激 励信号并输出第一差动信号即图中电桥的输出信号U o1，所述感应单元与激励单元进行耦合形成变压器调理电路并输出第二差动信号即变压器的输出信号U o2；
差动信号处理单元，用于接收所述第一差动信号U o1、第二差动信号U o2，分析在交变磁场下第一差动信号U o1的参数、第二差动信号U o2的参数与提离的关系，并将第一差动信号U o1的参数与第二差动信号U o2的参数进行融合，消去提离对信号的影响。
其中，激励单元由多个并排成一列的激励线圈组成，感应单元由多个与所述激励线圈一一对应放置的感应线圈组成，其中，所述感应线圈和激励线圈的线圈绕行方向相反；
所述涡流检测电路还包括第一差动放大器和第二差动放大器，所述激励线圈的输入端与所述信号发生器的输出端连接，多个所述激励线圈并联，所述激励线圈的输出端连接有电容器或电阻器；相邻两个激励线圈的输出端均连接至一个第一差动放大器，所述第一差动放大器用于放大输出第一差动信号U o1；相邻两个所述感应线圈的输出端接至一个第二差动放大器，所述第二差动放大器用于放大输出第二差动信号U o2。
具体地，如图1-图5所示，探头结构由两组水平放置的两组平面方形螺旋线圈组成，每一组线圈包含两个同等大小的方形线圈，其中一组是激励线圈，另一组是感应线圈，激励线圈为并联连接方式，感应线圈绕行方向与所述激励线圈相反，所述激励线圈和所述感应线圈并排放置在同一个平面，线圈的缠绕方式决定了这两组线圈的调理电路的差异性，其为差动电桥和变压器调理电路结合。需要注意的是，在其他实施例中，激励线圈和感应线圈可竖直放置，激励线圈的个数格局实际需求可以为大于2的偶数个。
进一步地，激励线圈和感应线圈并排放置在同一个平面，感应线圈接收到 的磁通总量为激励线圈产生的磁场和试件上涡流产生的磁场之和，在上下放置时由激励线圈产生的磁通直接穿入到感应线圈中的磁通量多(线圈之间的直接耦合)，因此背景信号强，而在相对水平放置时，线圈之间的由于耦合矢量距离大，耦合系数小，感应线圈中接收到的由激励线圈产生的磁通少，因此背景信号小，能够接收更多的有关试件的信息，能够比上下放置具有更好的提离抑制效果。其次，涡流在试件中的衰减速度与线圈半径呈负相关，水平放置时可将激励线圈视为圆心，激励线圈到感应线圈的距离视为半径，因此半径大，涡流的衰减速度更慢，从而理论上能够检测更深的缺陷。
进一步地，在一示例中，提供一种差动电桥，激励单元包括两个激励线圈，相邻两个所述激励线圈作为交流电桥的两臂，将对应的两个电容器或电阻器连接在交流电桥的其余两臂上，具体来说，如图2所示，激励线圈的L 1和L 2作为交流电桥的两个臂，剩下的两臂是两个容值相等为C的电容器，因此，两个电容器的差分电压为该组交流电桥输出，我们称之为U o1。激励线圈由两个大小、参数完全相同的两个线圈水平放置，两个线圈的公共端并联与信号发生器连接，剩下的一端分别与容值相等的电容进行串联连接，两个电容的另一端接地。电容两端的电压通入差动放大器，由此整个激励线圈的电流方向相同，且两个线圈与两个电容构成了一个电桥的连接方式。
进一步地，基于所述探头，提供一种变压器，感应线圈是两个线圈方向串联构成的，这两个线圈大小相等，线径相同，其各自的一端分别与差动放大器相连接，用于增加对缺陷的检测能力。因此把两个激励线圈当做一个整体，差分的感应线圈当做一个整体来看，如图3所示，激励线圈L 1和激励线圈L 2构成变压器的原边，而感应线圈L 3和感应线圈L 4构成变压器的副边。因此，我们可以从由感应线圈L 3和感应线圈L 4组成的差分感应线圈获得差分电压U o2。
进一步地，如图6所示，激励线圈的并联输入端与信号发生器连接，每个激励线圈的输出端均串联一个电容器后与所述第一差动放大器连接，所述第一差动放大器用于输出第一差动信号U o1；所述感应线圈的输出端与所述第二差动放大器连接，所述第二差动放大器用于输出第二差动信号U o2。具体地，信号发生器产生特定频率的正弦波信号，该信号被注入功率放大器，以增加探头的带载能力。激励线圈接收放大的交流信号，探头在交变电磁场下并与导体相互作用产生涡流，激励线圈通过第一差动放大器输出第一差动信号U o1，感应线圈在激励线圈和被测导体的相互影响下输出第二差动信号U o2，两路信号均输出至信号调理调理电路中，进一步被数据采集单元采集，最后通过差动信号处理单元进行后续分析。
进一步地，测试时，随着提离的距离的变化，被测导体试件上的涡流强度也发生变化，因此两个输出的幅值和相位发生变化，采集电路就是将变化的幅值和相位进行数据采集。
本发明探头采用差动电桥和变压器调理电路组合的方式，分别对激励单元和感应单元的输出进行幅值相位的多参数测量，双路差动输出在高提离变化时，对缺陷具有高检出能力，同时将两种差动信号的信号参数进行融合，可以抑制提离，且不需要调参等操作，简单实用。
在另一个示例中，如图4所示，将两个相邻的激励线圈作为一组，激励单元包括多组激励线圈，对应的感应单元包括多组感应线圈，每一组线圈的工作原理依照图1中线圈的实施方式。其中，所有的线圈位于同一水平面内。进行更多组差动输出信号参数的融合测量，更能精确地检测出缺陷。
在另一个示例中，如图5所示，一组激励线圈可对应两组感应线圈，其中，所有的线圈位于同一水平面内，两组感应线圈分别位于激励线圈的两侧，同理， 进行更多组差动输出信号参数的融合测量，更能精确地检测出缺陷。需要注意的是，基于该探头进行的其他阵列或者同原理进行改变，依然在本申请的保护范围之内。
实施例2
基于实施例1，提供一种涡流检测方法，包括以下步骤：
S1、在提离变化的情况下，获取探头输出的第一差动信号U o1以及第二差动信号U o2，其中，第一差动信号U o1由探头的激励单元输出，第二差动信号U o2由探头的感应单元输出；
S2、分析在交变磁场下第一差动信号U o1的参数、第二差动信号U o2的参数与提离的关系；
S3、将第一差动信号U o1的参数与第二差动信号U o2的参数进行融合，消去提离对信号的影响。
进一步地，所述S2包括：
计算所述第一差动信号U o1的幅值和相位参数，计算所述第二差动信号U o2的幅值和相位参数；
分别分析所述第一差动信号U o1的幅值、第一差动信号U o1的相位、第二差动信号U o2的幅值、第二差动信号U o2的相位与提离的关系。
进一步地，所述S3包括：
将所述第一差动信号U o1的幅值与所述第二差动信号U o2的幅值进行融合；
对所述第一差动信号U o1和、/或第二差动信号U o2的相位参数进行线性处理；
将融合后的幅值与线性处理后的相位参数进行融合，得到最终的检测信号。根据所述最终的检测信号分析试件的缺陷。
具体地，参见图7-图10，为了分析所提出的探头在提离的变化下，信号特征与提离的映射关系，我们基于等效电路模型建立系统输出响应。对于激励线圈而言，由于两个线圈的励磁电流方向相同，两个线圈中间区域的磁场方向相反。因此，由激励线圈L 1和激励线圈L 2组成的磁场区域可以视为在互感M 12相互作用下的整体。如果我们将被测导体与线圈构成整体视为一个系统，那么电桥的输出即为这一对并联的线圈(即L 1，L 2)构成的整体L v与被测导体产生电磁耦合。虽然差动电桥的输出是差分信号，用于放大可能破坏电桥平衡的外部输入差分信号，抑制共模信号如(温度等)，但是当提离变化时，并没有产生破坏平衡的量，因此只要提离变化时，电桥的输出为提离变化结果。若缺陷位于单线圈桥臂下方，桥的平衡将被打破，则差模输出为缺陷响应信号。而对于变压器感应线圈而言，其不仅接收由激励线圈直接耦合的磁场，还要接收被测导体上涡流的反射磁场(感应线圈自身与被测导体的磁场可忽略)，从结果来看，差动线圈的输出为两者差值之后的结果，亦将差动线圈(即L 3，L 4)视为一个整体L r。
进一步地，分别获取所述第一差动信号U o1、第二差动信号U o2，包括：
将被测导体等效为一个具有电感和电阻的线圈，分别建立第一差动信号U o1、第二差动信号U o2对应的等效电路，并基于该等效电路进行建模。将被测导体等效为一个具有电感L t和电阻R t的线圈，根据基尔霍夫定律可以进行建模，从而对两路信号在提离变化下基于等效电路进行建模可以得到：
Figure PCTCN2022141800-appb-000001
其中R v，L v是指在磁场的作用下，两个并联的激励线圈构成等效电阻和等效电感。I v是通入到激励线圈的等效电流，U p是指通入到线圈的正弦信号的电压。f是指通入的激励信号频率，而I e是在导体上产生的涡流。M vt是激励线圈与被 测导体之间的互感且与提离距离x有关，k vt是激励线圈与被测导体之间的耦合系数。
Figure PCTCN2022141800-appb-000002
其中，0<k vt(x)<1，从(1)中我们可以得到电流I v和阻抗Z v变化：
Figure PCTCN2022141800-appb-000003
Figure PCTCN2022141800-appb-000004
对于电桥的输出U o1，主要输出两路的电流的变化，而电流的变化 ΔI v主要取决于阻抗的变化ΔZ v，因此有以下两式：
Figure PCTCN2022141800-appb-000005
Figure PCTCN2022141800-appb-000006
其中，C s为与线圈串联的电容器的容值，进而我们可以得到U o1变化的幅值|ΔU O1|和相位参数
Figure PCTCN2022141800-appb-000007
Figure PCTCN2022141800-appb-000008
同样地，对于第二级差动变压器输出的变化|ΔU 02|为：
Figure PCTCN2022141800-appb-000009
其中k rt(x)是指感应线圈与被测导体的互感系数，同样该系数与提离距离x 有关。
第二级差动变压器输出的相位变化
Figure PCTCN2022141800-appb-000010
为：
Figure PCTCN2022141800-appb-000011
进一步地，所述将所述第一差动信号的幅值|ΔU O1|与所述第二差动信号的幅值|ΔU O2|进行融合，包括：
利用第一差动信号U o1的幅值与第二差动信号U o2的幅值之间的关系，消去提离对两个差动信号幅值参数的共同影响。从模型中可以发现，提离对两个输出通道的幅值参数有共同的影响，即k vt,且它们的影响是成负相关的。于是，我们提出利用他们的幅值关系，消去k vt的影响：
Figure PCTCN2022141800-appb-000012
所述对所述第一差动信号U o1和、/或第二差动信号U o2的相位参数进行线性处理，包括：
利用所述第一差动信号U o1和、/或第二差动信号U o2的相位参数进行微分操作，去除其非线性性。从(10)式可得，幅值融合后的变化量只与感应线圈和涡流的耦合系数有关，该量反映了更多的有关试件的信息。而(7)式反映了，该路信号的相位与提离无关，但是存在非线性性，因此我们可以利用相位的微分操作，去除其非线性性，与存在的幅值信号融合，便可增强缺陷信息。即：
Figure PCTCN2022141800-appb-000013
得到用于试件缺陷检测最终的融合检测信号为：
Figure PCTCN2022141800-appb-000014
本方法采用差动电桥和变压器调理电路组合的方式，进行幅值相位的多参 数测量，双路差动输出在高提离变化时，对缺陷具有高检出能力；同时利用所测量的多参数提出了融合计算，可以抑制提离，在提离变化时可以提高缺陷检测能力，且不需要调参等操作，简单实用。
实施例3
基于与实施例2相同的发明构思，提供一种涡流检测系统，所述系统包括：
差动信号获取模块，用于在提离变化的情况下，获取探头输出的第一差动信号U o1以及第二差动信号U o2，其中，第一差动信号U o1由探头的激励单元输出，第二差动信号U o2由探头的感应单元输出；
参数计算模块，用于分析在交变磁场下第一差动信号U o1的参数、第二差动信号U o2的参数与提离的关系；
多参数融合模块，用于将第一差动信号U o1的参数与第二差动信号U o2的参数进行融合，消去提离对信号的影响。
其中，多参数融合模块，用于将所述第一差动信号U o1的幅值与所述第二差动信号U o2的幅值进行融合，对所述第一差动信号U o1和、/或第二差动信号U o2的相位参数进行线性处理；并将融合后的幅值与线性处理后的相位参数进行融合，得到最终的检测信号；
缺陷分析模块，用于根据所述最终的检测信号分析试件的缺陷。
其中，多参数融合模块利用第一差动信号U o1的幅值与第二差动信号U o2的幅值之间的关系，消去提离对两个差动信号幅值参数的共同影响，幅值融合后的变化量只与感应线圈和涡流的耦合系数有关，该量反映了更多的有关试件的信息。利用所述第一差动信号U o1和、/或第二差动信号U o2的相位参数进行微分操作，去除其非线性性。利用相位的微分操作，去除其非线性性，与存在的幅 值信号融合，便可增强缺陷信息。
实施例4
基于实施例3，在该实施例中，对该探头的检测效果以及检测方法进行实例验证，具体地，首先验证检测提离增大时候的两路输出信号变化，参照图11-图14所示，将探头在一个点一直往上提的过程中，两路输出信号输出的变化具有差异性，如图11所示，对于电桥的输出，随着提离的增加，输出信号的幅值先增大后减小，如图12所示，而对于变压器的输出，在同等条件下，输出信号的幅值先减小后增大，因此反映了两个输出针对同一个变化量测得的参数是不相同的，这也为提离融合抑制方法的提出奠定了基础。
进一步地，验证参数融合检测方法的效果，如图15所示，经过参数融合之后，本来非线性变化的曲线，整体变化比较平缓，这表明了，随着提离的变化，最终的变化不大，同时验证了该融合方法具有提离抑制的效果。
进一步地，验证探头传感器在提离逐渐增大时对不同缺陷的检测效果和信号融合结果，如图16所示，分别对一块带有不同类型的缺陷的试件进行测试，其中，不同类型的缺陷包括圆形尺寸变化缺陷、深度变化缺陷、方向性缺陷和宽度变化缺陷。将平板试件垫高一段距离后，我们将探头对同一类型的缺陷进行扫查，以此模拟当提离连续增加时候的缺陷检测过程。从图中我们可以看出，融合后的信号能够很容易的分辨出缺陷。
进一步地，验证探头传感器在对沿焊缝裂纹进行检测的效果和信号融合结果，在为了验证该方法在复杂环境下的适应性，如图17所示，考虑了不规则提离变化情况，三组低碳X70钢(电导率为7.77·测试了沿焊缝有裂纹的弯管，弯管决定了提离距离在检测过程中总是不规则地变化)。此外，焊缝处的粗糙表面 和材料堆积导致提离变化，这也给检测带来了困难。与连续提离变化过程不同，在这种非线性提离变化过程中，很难从原始信号中识别缺陷信息，无法直接从原始信号中确定缺陷的数量。然而，所有缺陷都可以从提出的参数融合响应模型中清楚地获得。
进一步地，验证探头传感器在对管道缺陷进行检测的效果和信号融合结果，在对管道内壁缺陷进行检测时，很难从原始信号中分辨出缺陷的个数，而从融合后的数据来看，如图18所示，所有的缺陷均能够清晰的显示，表明了融合能够增加缺陷的检测能力且具有良好的信噪比。
实施例5
本实施例与实施例2具有相同的发明构思，在实施例2的基础上提供了一种存储介质，其上存储有计算机指令，所述计算机指令运行时执行所述涡流检测方法。
基于这样的理解，本实施例的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本发明各个实施例方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(Read-Only Memory，ROM)、随机存取存储器(Random Access Memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
实施例6
本实施例与实施例1具有相同的发明构思，提供一种终端，包括存储器和 处理器，存储器上存储有可在处理器上运行的计算机指令，处理器运行计算机指令时执行所述涡流检测方法。
处理器可以是单核或者多核中央处理单元或者特定的集成电路，或者配置成实施本发明的一个或者多个集成电路。
本说明书中描述的主题及功能操作的实施例可以在以下中实现：有形体现的计算机软件或固件、包括本说明书中公开的结构及其结构性等同物的计算机硬件、或者它们中的一个或多个的组合。本说明书中描述的主题的实施例可以实现为一个或多个计算机程序，即编码在有形非暂时性程序载体上以被数据处理装置执行或控制数据处理装置的操作的计算机程序指令中的一个或多个模块。可替代地或附加地，程序指令可以被编码在人工生成的传播信号上，例如机器生成的电、光或电磁信号，该信号被生成以将信息编码并传输到合适的接收机装置以由数据处理装置执行。
本说明书中描述的处理及逻辑流程可以由执行一个或多个计算机程序的一个或多个可编程计算机执行，以通过根据输入数据进行操作并生成输出来执行相应的功能。所述处理及逻辑流程还可以由专用逻辑电路—例如FPGA(现场可编程门阵列)或ASIC(专用集成电路)来执行，并且装置也可以实现为专用逻辑电路。
适合用于执行计算机程序的处理器包括，例如通用和/或专用微处理器，或任何其他类型的中央处理单元。通常，中央处理单元将从只读存储器和/或随机存取存储器接收指令和数据。计算机的基本组件包括用于实施或执行指令的中央处理单元以及用于存储指令和数据的一个或多个存储器设备。通常，计算机还将包括用于存储数据的一个或多个大容量存储设备，例如磁盘、磁光盘或光盘等，或者计算机将可操作地与此大容量存储设备耦接以从其接收数据或向其 传送数据，抑或两种情况兼而有之。然而，计算机不是必须具有这样的设备。此外，计算机可以嵌入在另一设备中，例如移动电话、个人数字助理(PDA)、移动音频或视频播放器、游戏操纵台、全球定位系统(GPS)接收机、或例如通用串行总线(USB)闪存驱动器的便携式存储设备，仅举几例。
虽然本说明书包含许多具体实施细节，但是这些不应被解释为限制任何发明的范围或所要求保护的范围，而是主要用于描述特定发明的具体实施例的特征。本说明书内在多个实施例中描述的某些特征也可以在单个实施例中被组合实施。另一方面，在单个实施例中描述的各种特征也可以在多个实施例中分开实施或以任何合适的子组合来实施。此外，虽然特征可以如上所述在某些组合中起作用并且甚至最初如此要求保护，但是来自所要求保护的组合中的一个或多个特征在一些情况下可以从该组合中去除，并且所要求保护的组合可以指向子组合或子组合的变型。
类似地，虽然在附图中以特定顺序描绘了操作，但是这不应被理解为要求这些操作以所示的特定顺序执行或顺次执行、或者要求所有例示的操作被执行，以实现期望的结果。在某些情况下，多任务和并行处理可能是有利的。此外，上述实施例中的各种系统模块和组件的分离不应被理解为在所有实施例中均需要这样的分离，并且应当理解，所描述的程序组件和系统通常可以一起集成在单个软件产品中，或者封装成多个软件产品。
以上具体实施方式是对本发明的详细说明，不能认定本发明的具体实施方式只局限于这些说明，对于本发明所属技术领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干简单推演和替代，都应当视为属于本发明的保护范围。

Claims (10)

  1. 一种涡流检测电路，其特征在于，包括：
    探头，包括激励单元和感应单元，所述激励单元形成差动电桥用于接收激励信号并输出第一差动信号，所述感应单元和用于与激励单元进行耦合形成变压器调理电路并输出第二差动信号；
    差动信号处理单元，用于接收所述第一差动信号、第二差动信号，分析在交变磁场下第一差动信号的参数、第二差动信号的参数与提离的关系，并将第一差动信号的参数与第二差动信号的参数进行融合，消去提离对信号的影响。
  2. 根据权利要求1所述的一种涡流检测电路，其特征在于，激励单元由多个并排成一列的激励线圈组成，感应单元由多个与所述激励线圈一一对应放置的感应线圈组成，其中，所述感应线圈和激励线圈的线圈绕行方向相反；
    所述激励线圈的输入端与所述信号发生器的输出端连接，多个所述激励线圈并联，所述激励线圈的输出端连接有电容器或电阻器；相邻两个激励线圈的输出端均连接至一个第一差动放大器；相邻两个所述感应线圈的输出端接至一个第二差动放大器。
  3. 根据权利要求1所述的一种涡流检测电路，其特征在于，所述激励线圈和所述感应线圈并排放置，相邻两个所述激励线圈作为交流电桥的两臂，将对应的两个电容器或电阻器连接在交流电桥的其余两臂上。
  4. 一种涡流检测方法，其特征在于，包括以下步骤：
    S1、在提离变化的情况下，获取探头输出的第一差动信号以及第二差动信号，其中，第一差动信号由探头的激励单元输出，第二差动信号由探头的感应单元输出；
    S2、分析在交变磁场下第一差动信号的参数、第二差动信号的参数与提离的关系；
    S3、将第一差动信号的参数与第二差动信号的参数进行融合，消去提离对信号的影响。
  5. 根据权利要求4所述的一种涡流检测方法，其特征在于，所述S2包括：
    计算所述第一差动信号的幅值和相位参数，计算所述第二差动信号的幅值和相位参数；
    分别分析所述第一差动信号的幅值、第一差动信号的相位、第二差动信号的幅值、第二差动信号的相位与提离的关系。
  6. 根据权利要求4所述的一种涡流检测方法，其特征在于，所述S3包括：
    将所述第一差动信号的幅值与所述第二差动信号的幅值进行融合；
    对所述第一差动信号和、/或第二差动信号的相位参数进行线性处理；
    将融合后的幅值与线性处理后的相位参数进行融合，得到最终的检测信号。
  7. 根据权利要求6所述的一种涡流检测方法，其特征在于，所述对所述第一差动信号和、/或第二差动信号的相位参数进行线性处理，包括：
    利用所述第一差动信号和、/或第二差动信号的相位参数进行微分操作，去除其非线性性。
  8. 一种涡流检测系统，其特征在于，所述系统包括：
    差动信号获取模块，用于在提离变化的情况下，获取探头输出的第一差动信号以及第二差动信号，其中，第一差动信号由探头的激励单元输出，第二差动信号由探头的感应单元输出；
    参数计算模块，用于分析在交变磁场下第一差动信号的参数、第二差动信号的参数与提离的关系；
    多参数融合模块，用于将第一差动信号的参数与第二差动信号的参数进行融合，消去提离对信号的影响。
  9. 一种存储介质，其上存储有计算机指令，其特征在于，所述计算机指令运行时执行权利要求4-7中任意一项所述涡流检测方法。
  10. 一种终端，包括存储器和处理器，存储器上存储有可在处理器上运行的计算机指令，其特征在于，所述处理器运行计算机指令时执行权利要求4-7中任意一项所述涡流检测方法。
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