EP4248182A1 - Device for non-destructive inspection of a structure, comprising an electromagnetic noise reduction member - Google Patents
Device for non-destructive inspection of a structure, comprising an electromagnetic noise reduction memberInfo
- Publication number
- EP4248182A1 EP4248182A1 EP21801568.3A EP21801568A EP4248182A1 EP 4248182 A1 EP4248182 A1 EP 4248182A1 EP 21801568 A EP21801568 A EP 21801568A EP 4248182 A1 EP4248182 A1 EP 4248182A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- transducer
- destructive testing
- testing device
- noise sensor
- electrical signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000009467 reduction Effects 0.000 title claims abstract description 17
- 238000007689 inspection Methods 0.000 title abstract description 6
- 230000001066 destructive effect Effects 0.000 title abstract 2
- 230000001902 propagating effect Effects 0.000 claims abstract description 4
- 238000009659 non-destructive testing Methods 0.000 claims description 22
- 230000010363 phase shift Effects 0.000 claims description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims 1
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- 238000010586 diagram Methods 0.000 description 9
- 230000036541 health Effects 0.000 description 7
- 230000005540 biological transmission Effects 0.000 description 5
- 230000007547 defect Effects 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 230000008878 coupling Effects 0.000 description 4
- 238000010168 coupling process Methods 0.000 description 4
- 238000005859 coupling reaction Methods 0.000 description 4
- 230000003993 interaction Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 230000011664 signaling Effects 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 101100153331 Mus musculus Timp1 gene Proteins 0.000 description 2
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- 230000003137 locomotive effect Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- G01H11/00—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties
- G01H11/02—Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by detecting changes in electric or magnetic properties by magnetic means, e.g. reluctance
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
- G01N29/2412—Probes using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/32—Arrangements for suppressing undesired influences, e.g. temperature or pressure variations, compensating for signal noise
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/4463—Signal correction, e.g. distance amplitude correction [DAC], distance gain size [DGS], noise filtering
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/04—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with electromagnetism
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B2201/00—Indexing scheme associated with B06B1/0207 for details covered by B06B1/0207 but not provided for in any of its subgroups
- B06B2201/50—Application to a particular transducer type
- B06B2201/52—Electrodynamic transducer
- B06B2201/54—Electromagnetic acoustic transducers [EMAT]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/26—Scanned objects
- G01N2291/262—Linear objects
- G01N2291/2623—Rails; Railroads
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/26—Scanned objects
- G01N2291/262—Linear objects
- G01N2291/2626—Wires, bars, rods
Definitions
- the invention relates to the field of non-destructive testing of longitudinal structures, for example an electric cable, a railway track or a pipe, with the aim of controlling the state of health of the structure and identifying the presence of defects, for example a crack, an incipient break or a clean break.
- Active structure inspection techniques using ultrasonic waves generally consist of generating waves in the structure or on the surface of the structure using sensors, then measuring the properties of the propagated waves using one or more sensors positioned on the structure.
- the ultrasonic waves generated in the structure to be studied can propagate over great distances, a fortiori in a longitudinal structure. Since ultrasonic waves are sensitive to defects, the measurements contain information concerning the state of "health" of the structure. The measurements carried out make it possible to detect a wide variety of defects. Under certain conditions, it is also possible to locate and quantify certain defects.
- the invention relates more particularly to the field of non-destructive testing devices based on electromagnetic acoustic transducers (EMAT) which aim to generate an ultrasonic wave directly in the part to be inspected by electromagnetic coupling without the need to physically connect to the room.
- EMAT electromagnetic acoustic transducers
- This type of device makes it possible to avoid the use of couplant, which induces limitations for applications for monitoring very long structures such as electric cables.
- the fact of being able to carry out an electromagnetic coupling without direct contact makes it possible, for example, to embark the device on board a train to carry out the inspection of the rails at high speeds.
- the invention applies more generally to any type of sensor comprising an electromagnetic transmitter and one or more receiver(s) of different forms of electromagnetic coils but also magnetic sensors of the giant magnetoresistance (GMR) type, tunnel magnetoresistance ( TMR), or anisotropic magnetoresistance (AMR).
- GMR giant magnetoresistance
- TMR tunnel magnetoresistance
- AMR anisotropic magnetoresistance
- EMAT sensors based on transducers having a coil in the form of a meander in reception have high frequency selectivity.
- the surrounding high voltage and the currents crossing the part to be inspected create significant noise (of the order of the useful signal) at the sensitivity frequency of the sensor .
- Another solution consists in performing synchronous detection or coherent demodulation of the signal, for example by modulating the magnetic field.
- this technique is difficult to implement for an on-board inspection in the railway context because the inspection is done at high speeds.
- the patent application W02008137231 also proposes a noise reduction method based on a differential measurement to suppress the electromagnetic noise of the locomotive engine on the communication coils of a signaling system.
- This method is not applicable for a non-destructive testing device because it does not allow to analyze the state of health of a rail.
- the device proposed in this patent application is based on two sensors positioned on two separate rails and does not provide for the generation of an ultrasonic wave propagating in the same rail in order to control the state of this rail.
- the present invention provides a device incorporating a member for reducing electromagnetic noise picked up by the receiving transducer. Noise reduction is achieved by subtracting the disturbing signal picked up by the transmission transducer from the useful signal picked up by the reception transducer.
- the subject of the invention is a device for non-destructive testing of a structure, comprising a first transducer capable of generating a main ultrasonic wave propagating in the structure, a second transducer capable of picking up the main ultrasonic wave after its propagation in the structure and converting it into a main electrical signal and a noise sensor, the noise sensor and the second transducer being capable of picking up one or more electromagnetic interference signals and converting them into a secondary electrical signal, the device comprising a acquisition module configured to measure, over a same acquisition time window, the signals picked up by the noise sensor and by the second transducer, the device further comprising a noise reduction device connected to the noise sensor and to the second transducer and configured to subtract the secondary electrical signal measured by the noise sensor from the primary electrical signal measured by the second transducer.
- the secondary electrical signal is measured simultaneously by the noise sensor and by the second transducer.
- the noise sensor is produced by the first transducer.
- the first transducer and the second transducer each comprise one or more identical field coil(s).
- the first transducer and the second transducer each comprise one or more different field coil(s) and the noise reduction member is configured to normalize the amplitude of the signal secondary electrical signal measured by the first transducer relative to the amplitude of the primary electrical signal measured by the second transducer.
- the noise sensor is produced by a third transducer, the first transducer and the second transducer each comprising one or more different field coil(s).
- the noise sensor is produced by a coil.
- the third transducer is identical to the second transducer.
- the main ultrasonic wave is a pulse signal having a duration less than the wave propagation time in the structure between the first transducer and the second transducer.
- the acquisition time window begins at a time greater than the sum of the time of generation of the main ultrasonic wave and the duration of the pulse signal and has a duration at least equal to the propagation time of the ultrasonic wave between the first transducer and the second transducer.
- the structure to be checked is a longitudinal structure, for example a railway rail, an electric cable or a pipeline.
- the first transducer, the second transducer and the noise sensor are intended to be positioned above the structure to be controlled with the same air gap and the same orientation with respect to the longitudinal axis of the structure.
- FIG. 1 represents a block diagram of an electromagnetic acoustic transducer
- FIG. 2 represents a diagram illustrating the influence of disturbing signals on the operation of a non-destructive testing device applied to a rail
- FIG. 3 represents a diagram of a device according to a first embodiment of the invention
- FIG. 4 represents a diagram of a device according to a second embodiment of the invention.
- the invention is described below for an application for monitoring the state of health of railway rails, but it is more generally applicable to any longitudinal structure, for example an electric power cable, or a pipeline, the environment of which is subject to electromagnetic interference.
- FIG. 1 represents several diagrams illustrating the operation of an electro-magnetic acoustic transducer or EMAT (ElectroMagnetic Acoustic Transducer) transducer.
- This type of transducer consists of one or more induction coils B and one or more permanent magnets (or electromagnets) A.
- the coils can take different shapes (meanders, cylindrical, etc.). These elements induce eddy currents and radiate electromagnetic excitations (dynamic and static) which interact with the microstructure of the inspected part (conductive medium, magnetic or not). These interactions generate the dynamic sources (volume and surface) at the origin of the ultrasonic wave generated by the transducer in the medium: it is an electro magneto-elastic coupling.
- a transducer is composed of a coil able to generate an eddy current and a magnet or an electromagnet able to generate a magnetic field. The interaction between these two elements allows the generation or detection of ultrasonic waves in the structure to be controlled.
- EMAT transducers allow the generation and reception of ultrasonic waves without contact and therefore without mechanical coupling with the part. They are capable of generating and receiving a wide variety of wave types (surface, volume and guided) and polarizations depending on the geometric configuration of the coils and the polarization of the permanent magnets.
- a transducer operating in reception can be produced by a magnetic sensor of the giant magnetoresistance (GMR), tunnel magnetoresistance (TMR) or anisotropic magnetoresistance (AMR) type.
- GMR giant magnetoresistance
- TMR tunnel magnetoresistance
- AMR anisotropic magnetoresistance
- the transducer still comprises a magnet or electromagnet but the coil is replaced by an integrated circuit or a chip on silicon sensitive to magnetic fields.
- the transducer operating in transmission comprises, for its part, always a coil.
- Figure 2 shows a diagram of a non-destructive testing device for monitoring the state of health of a railway track. It consists of a first transducer E capable of generating an ultrasonic wave which propagates in the rail and a second transducer R capable of picking up the ultrasonic wave and converting it into an electrical signal. Analysis of the characteristics of this signal makes it possible to identify a fault in the section of the rail located between the two transducers.
- the ultrasonic wave generated is of the discontinuous type (for example: pulses, sinusoidal pulse train, etc.).
- the electromagnetic environment of the rail and the transducers is disturbed by electric fields EC and/or magnetic fields MC from the catenary C and traction or signaling currents flowing in the rail which generate also MR magnetic fields.
- the secondary electrical signal SP actually consists of an addition of several disturbing electrical signals from the various sources indicated above.
- this disturbing electrical signal is considered in the following as a whole.
- the transducers E and R are advantageously placed above the same rail with a preferably identical air gap for the two transducers. They are oriented identically to each other and preferably parallel to the axis of the rail. For this purpose, the transducers E and R are separate and can be positioned at distance from each other to be able to identify a defect in the section of the rail located between the two transducers.
- the transducers E and R are positioned on board a train, preferably under a wagon and above a rail, in its alignment. In this way, it is possible to continuously analyze the health of the rail while the train is running.
- Figure 3 schematizes an example of a non-destructive testing device according to an embodiment of the invention which consists of an adaptation of the device described in Figure 2.
- the secondary electrical signal Sp from the various sources of interference described above is received synchronously (or with a constant phase shift for GMR magnetic receivers, etc.) by the two transducers E, R.
- the first transducer E always comprises a coil which is sensitive to the electric current and can therefore pick up disturbing signals.
- the secondary electric signal propagates in the rail at the speed of the electric current which is much higher than the speed of propagation of the ultrasonic waves.
- the secondary electrical signal is received almost simultaneously by the two transducers if they have identical coils and they are positioned in the same plane parallel to the axis of the rail and the catenary.
- the ultrasonic wave generated by the first transducer E is only received by the second transducer R after a propagation time equal to the distance between the two transducers divided by the propagation speed of the ultrasonic wave.
- the invention then consists in subtracting from the signal measured by the second transducer R, that picked up by the first transducer E which comprises only the disturbance signal. Indeed, the useful signal received by the receiver R being delayed with respect to the transmission time, the subtraction of the two signals has no influence on the useful signal outside the transmission time window.
- the device according to the invention thus comprises a noise reduction unit ORG consisting of a subtractor, a first input of which receives the useful signal measured by the second transducer R and a second input receives the signal picked up by the first transducer E .
- the noise reduction unit also applies a constant phase shift to the signal from the first transducer E before the subtraction.
- the device according to the invention also comprises an ACQ acquisition module which makes it possible to control the synchronous acquisition of the two transducers E, R over a predetermined time window.
- the ACQ acquisition module performs analog signal acquisition.
- a digital analog converter (not shown in Figure 3) is responsible for converting the acquired signals digitally.
- the noise reduction unit ORG can be made in digital form and then be placed after the analog-to-digital converter, but it can also be made in analog form and be placed before the analog-to-digital converter.
- the acquisition time window (for the two transducers) begins at a time to+timp, with Lmp the duration of the generated pulse and has a duration at least equal to the propagation time of the ultrasonic wave between the two transducers.
- the subtraction of the two signals makes it possible to reduce or even cancel the synchronous disturbing signals and to retain only the useful signal.
- the invention thus makes it possible to improve the signal-to-noise ratio.
- the device according to the invention comprises a third transducer R 'whose coil is identical to the second transducer R which has the function of receiver.
- This third transducer R' has the role of picking up the disturbing signals.
- the noise reduction device ORG is then connected, by a first input to the second transducer R and by a second input to the third transducer R′.
- the third transducer R′ is distinct from the second transducer R and can be positioned at a distance from it.
- the third transducer does not include a magnet (it only includes a coil or a magnetic sensor) to capture only the secondary electrical signal and not be sensitive to the useful ultrasonic signal.
- a magnet it only includes a coil or a magnetic sensor
- the third transducer R′ includes a magnet (FIG. 4)
- a second out-of-phase useful signal can disturb the acquisition carried out on this transducer R′.
- the start of the acquisition time window must therefore be adapted to take into account the position of the third transducer R' and the propagation time of the signal between the transmitting transducer E and this third transducer.
- FIG. 4 gives the indication of the acquisition time window FT in dotted lines for the case where the transducer R′ comprises a magnet.
- Figure 5 illustrates the same principle for a transducer R' without magnet.
- the noise reduction device comprises an attenuator or an amplifier for applying an attenuation or amplification gain to the one of the two input signals in order to normalize it with respect to the other signal before carrying out the subtraction of the two signals.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR2011748A FR3116337B1 (en) | 2020-11-17 | 2020-11-17 | Device for non-destructive testing of a structure, comprising an electromagnetic noise reduction device |
PCT/EP2021/080761 WO2022106220A1 (en) | 2020-11-17 | 2021-11-05 | Device for non-destructive inspection of a structure, comprising an electromagnetic noise reduction member |
Publications (1)
Publication Number | Publication Date |
---|---|
EP4248182A1 true EP4248182A1 (en) | 2023-09-27 |
Family
ID=74045916
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP21801568.3A Pending EP4248182A1 (en) | 2020-11-17 | 2021-11-05 | Device for non-destructive inspection of a structure, comprising an electromagnetic noise reduction member |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP4248182A1 (en) |
FR (1) | FR3116337B1 (en) |
WO (1) | WO2022106220A1 (en) |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2965784B2 (en) * | 1992-04-14 | 1999-10-18 | 新日本製鐵株式会社 | Electromagnetic ultrasonic transducer |
US5581037A (en) * | 1992-11-06 | 1996-12-03 | Southwest Research Institute | Nondestructive evaluation of pipes and tubes using magnetostrictive sensors |
US6933932B2 (en) * | 2002-09-17 | 2005-08-23 | Texzec, Inc. | Acoustic wave sensor with EMAT drive |
US20080272246A1 (en) | 2007-05-02 | 2008-11-06 | Samuel Robert Mollet | Methods and systems for active noise cancellation |
US8998812B2 (en) * | 2010-09-13 | 2015-04-07 | General Electric Company | Ultrasound method and probe for electromagnetic noise cancellation |
WO2012034602A1 (en) * | 2010-09-15 | 2012-03-22 | Siemens Vai Metals Technologies Sas | Device for inspecting a moving metal strip |
-
2020
- 2020-11-17 FR FR2011748A patent/FR3116337B1/en active Active
-
2021
- 2021-11-05 EP EP21801568.3A patent/EP4248182A1/en active Pending
- 2021-11-05 WO PCT/EP2021/080761 patent/WO2022106220A1/en unknown
Also Published As
Publication number | Publication date |
---|---|
FR3116337A1 (en) | 2022-05-20 |
WO2022106220A1 (en) | 2022-05-27 |
FR3116337B1 (en) | 2022-12-09 |
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