CN109187732A - A kind of barkhausen signal detection probe and measurement method with lift off measurement - Google Patents

A kind of barkhausen signal detection probe and measurement method with lift off measurement Download PDF

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CN109187732A
CN109187732A CN201811059874.9A CN201811059874A CN109187732A CN 109187732 A CN109187732 A CN 109187732A CN 201811059874 A CN201811059874 A CN 201811059874A CN 109187732 A CN109187732 A CN 109187732A
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lift
coil
detection
detection coil
barkhausen signal
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杭成
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Nanjing University of Aeronautics and Astronautics
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    • 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
    • G01N27/725—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating magnetic variables by using magneto-acoustical effects or the Barkhausen effect

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Abstract

本发明公开了一种带提离距离测量的巴克豪森信号检测探头及测量方法，检测探头由激励线圈绕制在U型磁轭上构成励磁器；提离检测线圈是由柔性电路板上的PCB线圈构成，提离检测线圈设在U型磁轭的两个脚上；巴克豪森信号检测线圈是由漆包线绕制而成的空心线圈，设在U型磁轭的中间，检测的巴克豪森信号经过放大、高通滤波、A/D采样，最终由PC进行保存和处理。提离检测方法采用提离检测线圈和谐振电容的LC并联谐振，基于电涡流效应，通过测量等效并联阻抗Rp和电感L的变化来测量提离距离。由于克服了提离效应，检测线圈测量的巴克豪森信号准确度更高。

The invention discloses a Barkhausen signal detection probe with lift-off distance measurement and a measurement method. The detection probe is wound on a U-shaped magnetic yoke by an excitation coil to form an exciter; the lift-off detection coil is made of a flexible circuit board. It is composed of PCB coil, and the lift-off detection coil is set on the two legs of the U-shaped yoke; the Barkhausen signal detection coil is an air-core coil made of enameled wire and is set in the middle of the U-shaped yoke. The Sen signal is amplified, high-pass filtered, A/D sampled, and finally saved and processed by a PC. The lift-off detection method adopts the LC parallel resonance of the lift-off detection coil and the resonant capacitor. Based on the eddy current effect, the lift-off distance is measured by measuring the changes of the equivalent parallel impedance R p and the inductance L. The Barkhausen signal measured by the detection coil is more accurate due to overcoming the lift-off effect.

Description

A kind of barkhausen signal detection probe and measurement method with lift off measurement
Technical field
The present invention relates to a kind of barkhausen signal detection probes and measurement method with lift off measurement, integrate simultaneously Barkhausen signal detection and lift off measurement, the detection for ferrimagnet stress and mechanical performance.
Background technique
Ferrimagnet is as manufacturing and the important materials of engineering, for ferrimagnet stress and mechanical performance It detects most important.Traditional detection technique mainly has X-ray diffraction method, Metallographic Analysis etc., but in the detection process can be right Material cause wear or destroy, and there are operating difficulties, measurement accuracy is low the problems such as, limit its application in engineering.
Magnetic Barkhausen noise detection method is answered in research and engineering as a kind of new lossless detection method With.Magnetic Barkhausen noise signal reflects the irreversible change and motion conditions of magnetic domain inside ferrimagnet.Due to magnetic domain The variation and movement of structure are closely related with the microstructure and stress state of material, it is possible to be used for material internal and answer The detection and evaluation of power and mechanical performance.
Since barkhausen signal is influenced by Lift-off effect, that is, the electromagnetic field effect changed is on ferrimagnet, material Interior generation magnetic barkhausen signal size can change at a distance from conductor with variation electromagnetic field and be changed.So for lift-off away from From being detected, the precision of barkhausen signal detection can be effectively improved, to more accurately detect material internal stress And mechanical performance.
The lift off of Barkhausen's detection probe needs very high detection accuracy in millimeter to a centimetre rank.Currently, It using the detecting distance method of ultrasonic wave or infrared distance measurement, is affected by bad border, such as dirt, dust etc., and exists and survey The problems such as accuracy of measurement is low, there are measurement blind areas.
The present invention proposes a kind of barkhausen signal detection probe and measurement method with lift off measurement, realizes inspection The lift off of measuring probe while surveying barkhausen signal, not (the remote ultra-traditional distance detection in the micron-scale of the precision of measurement Method), the influence that can be effectively compensated for or overcome lift off to barkhausen signal.Compared to traditional single Barkhausen Detection probe can accurately measure barkhausen signal.
Summary of the invention
Goal of the invention: the purpose of the present invention is design it is a kind of with lift off measurement barkhausen signal detection probe and Measurement method can overcome influence of the lift off to barkhausen signal compared to single barkhausen signal detection probe, Have the advantages that measurement is accurate, easy to operate.
Technical solution: a kind of barkhausen signal detection probe with lift off measurement, including U-shaped magnetic yoke, excitation line Circle, lift-off detection coil and barkhausen signal detection coil；It is wound in U-shaped magnetic yoke by excitation coil and constitutes magnetizing exciter；It mentions It from detection coil is made of the PCB coil on flexible circuit board, lift-off detection coil is located on two feet of U-shaped magnetic yoke；Bar Ke Haosen signal detection coil is the air core coil as made of enameled wire coiling, is located at the centre of U-shaped magnetic yoke, the Bark person of outstanding talent of detection Gloomy signal is finally saved and is handled by PC by amplification, high-pass filtering, A/D sampling.
The lift-off detection coil is made of the PCB coil on flexible circuit board, and two feet of U-shaped magnetic yoke are placed on On；Or be made of the coil of enameled wire coiling, it is placed on two foot sides of U-shaped magnetic yoke.
A kind of measurement method of the barkhausen signal detection probe with lift off measurement, using lift-off detection coil and Capacitor LC parallel resonance is based on eddy current effect, by measuring equivalent parallel impedance RpVariation with inductance L come measure lift-off away from From.Due to overcoming Lift-off effect, the barkhausen signal accuracy of measurement is higher.It is as follows to measure lift off process:
Step 1:[frequency sweep] Direct Digital Synthesizer (DDS chip) is used, the sine wave of variable frequency is exported, is made It obtains LC antiresonant circuit and is constantly in resonant state；
Step 2:[frequency measurement] by timer measurement resonance frequency, so that inductance value L be calculated indirectly；
Step 3:[survey impedance] measurement inductance capacitance LC resonance circuit impedance；
Step 4:[data are fitted] since equivalent parallel impedance, inductance and lift off are not stringent linear relationship, institute With the nonlinear fitting of data to be carried out, then the different ferrimagnets detected to needs establish model library.
The utility model has the advantages that compared with prior art, the barkhausen signal detection provided by the invention with lift off measurement Probe and measurement method, have the advantages that
1. the integrated barkhausen signal detection of probe and lift off measurement.
2. influence of the lift-off to barkhausen signal can be overcome by the detection of lift off.
3. being based on eddy current effect, the detection of lift off is not influenced by grease, dust.
4. the measurement accuracy of lift off is other in the micron-scale.
5. carrying out Database Modeling for the plate needed, the lift off and Bark of all ferrimagnets can detecte The gloomy signal of person of outstanding talent.
Detailed description of the invention
Fig. 1 is the barkhausen signal detection probe schematic device with lift off measurement；
Fig. 2 is the another way figure of lift-off measuring coil installation；
Fig. 3 is lift off measurement model schematic diagram.
Specific embodiment
Combined with specific embodiments below, the present invention is furture elucidated, it should be understood that these embodiments are merely to illustrate the present invention Rather than limit the scope of the invention, after the present invention has been read, those skilled in the art are to various equivalences of the invention The modification of form falls within the application range as defined in the appended claims.
The detection probe of the detection of a kind of while integrated barkhausen signal and lift off measurement that the present invention designs, device Schematic diagram is as shown in Figure 1.It is wound in U-shaped magnetic yoke by excitation coil and constitutes magnetizing exciter, can produce the magnetic field of alternation.Lift-off inspection Test coil is made of the PCB coil on flexible circuit board (FPC), and FPC coil can be made very thin, can be placed in U-shaped magnetic On two feet of yoke.Detection coil is the air core coil as made of enameled wire coiling, is placed on the centre of U-shaped magnetic yoke, bar of detection Ke Haosen signal is finally saved and is handled by PC by amplification, high-pass filtering, A/D sampling.If lift-off detection coil is The coil of enameled wire coiling can be placed on magnetic yoke side, as shown in Figure 2.
The present invention is based on eddy current effects to measure lift off.When being connected with alternating current in coil, meeting around coil An alternating magnetic field is generated, the conductor being placed in magnetic field can generate current vortex, and current vortex can generate a new magnetic field, and direction With former magnetic field on the contrary, so part original magnetic field can be offset, the effective impedance of hot-wire coil and inductance value is made to change.So surveying Lift off is measured, measurement effective impedance and inductance value can be passed through.
Since ferrimagnet will affect former electromagnetic field near inductance capacitance LC parallel resonance, the variation of eddy-current loss can To be equivalent to equivalent parallel resonant impedance Rp, the variation of winding inductance quantity L can be equivalent to the variation of resonance frequency.
The present invention is it is discovered by experiment that equivalent parallel resonant impedance RpSuitable for measuring apart from big situation, inductance L is suitable For measuring apart from lesser situation, since lift off is generally all in millimeter to Centimeter Level, it is possible to be combined with inductance L Equivalent parallel resonant impedance RpIt measures.Equivalent parallel resonant impedance RpMore sensitive to temperature, inductance L is relatively stable, institute With when distance fitting, the weight of inductance can be higher than equivalent parallel resonant impedance.
The connection method of integrated lift-off detection circuit and lift-off detection coil is as shown in figure 3, lift-off detection line in probe Parallel resonance capacitor C on circle, single-chip microcontroller/DSP control DDS chip drives LC resonance circuit by detection frequency, impedance, measure The step of lift off, is as follows:
Step 1:[frequency sweep] using single-chip microcontroller/DSP control Direct Digital Synthesizer (DDS chip), output is variable The sine wave of frequency, so that LC antiresonant circuit is constantly in resonant state.Single-chip microcontroller/DSP acquisition lift-off detection coil Voltage illustrates that LC is in resonant state when voltage maximum, and single-chip microcontroller/DSP control DDS exports the frequency sine at this time Wave.
Step 2:[frequency measurement] by the resonance frequency in single-chip microcontroller/DSP timer measurement lift-off detection coil, thus It connects and inductance value L is calculated, as shown in formula (1).
Wherein, f is the resonance frequency of lift-off detection coil, and C is the capacitance of resonant capacitance, and π is pi.
Step 3:[survey impedance] measurement inductance capacitance LC resonance circuit impedance.It is adopted by the electric current being connected in the circuit LC Current signal is converted into voltage signal by sample resistance and operational amplifier, is believed with single-chip microcontroller/DSP sampling sampling resistor voltage Number, accurate current value is obtained, by the voltage V and electric current I in LC resonance circuit, the equivalent impedance of LC resonance circuit is calculated Rp, as shown in formula (2).
Step 4:[data are fitted] since equivalent parallel impedance, inductance L and lift off are not stringent linear relationship, institute With the nonlinear fitting of data to be carried out, then the different ferrimagnets detected to needs establish model library.

Claims (6)

1.一种带提离距离测量的巴克豪森信号检测探头，其特征在于：包括U型磁轭、激励线圈、提离检测线圈和巴克豪森信号检测线圈；由激励线圈绕制在U型磁轭上构成励磁器；提离检测线圈是由柔性电路板上的PCB线圈构成，提离检测线圈设在U型磁轭的两个脚上；巴克豪森信号检测线圈是由漆包线绕制而成的空心线圈，设在U型磁轭的中间，检测的巴克豪森信号经过放大、高通滤波、A/D采样，最终由PC进行保存和处理。1. a Barkhausen signal detection probe with lift-off distance measurement is characterized in that: comprising U-shaped yoke, excitation coil, lift-off detection coil and Barkhausen signal detection coil; The exciter is formed on the yoke; the lift-off detection coil is composed of a PCB coil on a flexible circuit board, and the lift-off detection coil is set on the two legs of the U-shaped yoke; the Barkhausen signal detection coil is wound by enameled wire. The formed hollow coil is set in the middle of the U-shaped yoke. The detected Barkhausen signal is amplified, high-pass filtered, A/D sampled, and finally saved and processed by the PC. 2.如权利要求1所述的带提离距离测量的巴克豪森信号检测探头，其特征在于：将提离检测线圈由柔性电路板上的PCB线圈构成改成提离检测线圈是由漆包线绕制的线圈，则将提离检测线圈设在U型磁轭的两个脚边上。2. The Barkhausen signal detection probe with lift-off distance measurement as claimed in claim 1, characterized in that: the lift-off detection coil is formed by a PCB coil on a flexible circuit board, and the lift-off detection coil is changed to be wound by an enameled wire. If the coil is made, the lift-off detection coil is set on the two legs of the U-shaped yoke. 3.如权利要求1所述的带提离距离测量的巴克豪森信号检测探头，其特征在于：探头内集成的提离检测电路和提离检测线圈的连接方式为：提离检测线圈上并联谐振电容C，单片机/DSP通过检测提离检测线圈的谐振频率、阻抗来控制DDS芯片驱动LC谐振电路。3. The Barkhausen signal detection probe with lift-off distance measurement as claimed in claim 1, characterized in that: the connection mode of the lift-off detection circuit integrated in the probe and the lift-off detection coil is: the lift-off detection coil is connected in parallel Resonant capacitor C, the microcontroller/DSP controls the DDS chip to drive the LC resonant circuit by detecting the resonant frequency and impedance of the lift-off detection coil. 4.一种带提离距离测量的巴克豪森信号检测探头的测量方法，其特征在于，测量提离距离流程如下：4. the measuring method of the Barkhausen signal detection probe of band lift-off distance measurement, is characterized in that, measuring lift-off distance flow process is as follows: 步骤1：使用直接数字式频率合成器，输出可变频率的正弦波，使得LC并联谐振电路一直处于谐振状态；Step 1: Use a direct digital frequency synthesizer to output a sine wave with variable frequency, so that the LC parallel resonant circuit is always in a resonance state; 步骤2：通过定时器测量谐振频率，从而间接计算得到电感值L；Step 2: The resonant frequency is measured by the timer, and the inductance value L is obtained by indirect calculation; 步骤3：测量电感电容LC谐振电路的阻抗；Step 3: Measure the impedance of the inductor-capacitor LC resonant circuit; 步骤4：由于等效并联阻抗、电感和提离距离不是严格的线性关系，所以要进行数据的非线性拟合，再对需要检测的不同铁磁性材料建立模型库。Step 4: Since the equivalent parallel impedance, inductance and lift-off distance are not strictly linear, the nonlinear fitting of the data should be performed, and then a model library should be established for different ferromagnetic materials to be detected. 5.如权利要求4所述的带提离距离测量的巴克豪森信号检测探头的测量方法，其特征在于，步骤2中电感值L，如公式(1)所示：5. the measuring method of the Barkhausen signal detection probe with lift-off distance measurement as claimed in claim 4, is characterized in that, in the step 2, inductance value L, as shown in formula (1): 其中，f为提离检测线圈的谐振频率，C为谐振电容的容值，π为圆周率。Among them, f is the resonance frequency of the lift-off detection coil, C is the capacitance of the resonance capacitor, and π is the pi. 6.如权利要求3所述的带提离距离测量的巴克豪森信号检测探头的测量方法，其特征在于，步骤3中通过电流采样电阻和运算放大器将电流信号转换成电压信号，用单片机/DSP采样电压信号，得到准确的电流值，通过回路的电压V和电流I，计算得到LC谐振电路的等效阻抗Rp，如公式(2)所示：6. the measuring method of the Barkhausen signal detection probe of band lift-off distance measurement as claimed in claim 3, it is characterized in that, in step 3, current signal is converted into voltage signal by current sampling resistance and operational amplifier, with single-chip microcomputer/ The DSP samples the voltage signal to obtain the accurate current value. Through the voltage V and current I of the loop, the equivalent impedance R p of the LC resonant circuit is calculated, as shown in formula (2):
CN201811059874.9A 2018-09-12 2018-09-12 A kind of barkhausen signal detection probe and measurement method with lift off measurement Pending CN109187732A (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111595493A (en) * 2020-06-29 2020-08-28 沈阳仪表科学研究院有限公司 Pipeline stress detection probe and method based on magnetostrictive inverse effect
CN112406318A (en) * 2020-11-24 2021-02-26 武汉先同科技有限公司 Ink quantity detection device and method based on inductance technology and ink-jet printer
CN114112736A (en) * 2020-08-28 2022-03-01 宝山钢铁股份有限公司 Online measuring device and method for determining fracture elongation of low-carbon steel cold-rolled sheet
CN114509499A (en) * 2022-01-27 2022-05-17 南昌航空大学 Focusing semicircular probe for eddy current defect detection of metal component and use method thereof
CN115950929A (en) * 2022-12-29 2023-04-11 国家石油天然气管网集团有限公司 Intelligent detection stick for DCVG detection and CIPS detection
CN116558675A (en) * 2023-05-09 2023-08-08 南昌航空大学 Alternating electromagnetic field stress detection signal processing method and device considering lift-off effect
CN117309130A (en) * 2023-08-25 2023-12-29 深圳拓竹科技有限公司 Method for measuring natural frequency of sliding block, 3D printing system and electronic equipment

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5992241A (en) * 1995-05-09 1999-11-30 Magyar Allamvasutak Reszvenytarsasag Method and device for determining the neutral temperature of welded tracks
US6310476B1 (en) * 1996-10-09 2001-10-30 Mitsubishi Heavy Industries, Ltd. Eddy current flaw detector
JP2012145486A (en) * 2011-01-13 2012-08-02 Kobe Steel Ltd Eddy current flaw detection probe, eddy current flaw detection device, and eddy current flaw detection method
CN104865309A (en) * 2015-04-07 2015-08-26 江苏省特种设备安全监督检验研究院 A method for reducing Barkhausen noise detection error and its sensor system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5992241A (en) * 1995-05-09 1999-11-30 Magyar Allamvasutak Reszvenytarsasag Method and device for determining the neutral temperature of welded tracks
US6310476B1 (en) * 1996-10-09 2001-10-30 Mitsubishi Heavy Industries, Ltd. Eddy current flaw detector
JP2012145486A (en) * 2011-01-13 2012-08-02 Kobe Steel Ltd Eddy current flaw detection probe, eddy current flaw detection device, and eddy current flaw detection method
CN104865309A (en) * 2015-04-07 2015-08-26 江苏省特种设备安全监督检验研究院 A method for reducing Barkhausen noise detection error and its sensor system

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
吴杰: "巴克豪森应力检测的提离消除及软硬件实现研究", 《中国优秀博硕士学位论文全文数据库(硕士)》 *
张朝晖: "《检测技术及应用 第2版》", 30 November 2011, 中国计量出版社 *
李科杰: "《传感技术》", 30 November 1989, 北京理工大学出版社 *
陈庆 等: "《传感器原理及应用》", 30 September 2012, 中国铁道出版社 *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111595493A (en) * 2020-06-29 2020-08-28 沈阳仪表科学研究院有限公司 Pipeline stress detection probe and method based on magnetostrictive inverse effect
CN114112736A (en) * 2020-08-28 2022-03-01 宝山钢铁股份有限公司 Online measuring device and method for determining fracture elongation of low-carbon steel cold-rolled sheet
CN114112736B (en) * 2020-08-28 2023-11-14 宝山钢铁股份有限公司 Online measuring device and method for determining fracture elongation of low-carbon steel cold-rolled sheet
CN112406318A (en) * 2020-11-24 2021-02-26 武汉先同科技有限公司 Ink quantity detection device and method based on inductance technology and ink-jet printer
CN114509499A (en) * 2022-01-27 2022-05-17 南昌航空大学 Focusing semicircular probe for eddy current defect detection of metal component and use method thereof
CN115950929A (en) * 2022-12-29 2023-04-11 国家石油天然气管网集团有限公司 Intelligent detection stick for DCVG detection and CIPS detection
CN116558675A (en) * 2023-05-09 2023-08-08 南昌航空大学 Alternating electromagnetic field stress detection signal processing method and device considering lift-off effect
CN116558675B (en) * 2023-05-09 2024-01-30 南昌航空大学 Alternating electromagnetic field stress detection signal processing method and device considering lift-off effect
CN117309130A (en) * 2023-08-25 2023-12-29 深圳拓竹科技有限公司 Method for measuring natural frequency of sliding block, 3D printing system and electronic equipment
CN117309130B (en) * 2023-08-25 2024-10-11 深圳拓竹科技有限公司 Method for measuring natural frequency of sliding block, 3D printing system and electronic equipment

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