# US 2019/0376785 A1 · Method, Apparatus, System and Sensor For Detecting Multi-Mode Electromagnetic Acoustic and Magnetic Flux Leakage

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- Number: US 2019/0376785 A1
- Document ID: US20190376785A1
- Status: Published application
- Kind: A1
- Application number: 16/478,858
- Filed: 2017-03-06
- Published: 2019-12-12
- Earliest claimed: 2017-01-18
- Assignees: Zhong Te Jian Technology & Development (Beijing) Co. Ltd; China Special Equipment Inspection & Research Institute
- Applicants: Zhong Te Jian Technology & Development (Beijing) Co. Ltd; China Special Equipment Inspection and Research Institute
- Inventors: Gongtian SHEN; Yang ZHENG; Zongjian ZHANG; Jidong TAN; Sujun LI
- Web page: https://patentgrep.com/patent/US20190376785A1

## CPC

- G01B 17/02: for measuring thickness
- G01N 29/2412: {using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]; (investigating the presence of flaws using eddy currents G01N27/90, magnetostrictive transducers B06B1/08, measuring magnetostrictive properties G01R33/18)}
- G01B 7/10: {using magnetic means, e.g. by measuring change of reluctance}
- G01N 27/83: by investigating stray magnetic fields
- G01N 27/9006: {Details, e.g. in the structure or functioning of sensors}
- G01N 29/041: {on the surface of the material, e.g. using Lamb, Rayleigh or shear waves}
- G01N 29/043: {in the interior, e.g. by shear waves}
- G01N 29/048: {Marking the faulty objects}
- G01N 29/225: {Supports, positioning or alignment in moving situation}
- G01N 29/348: {with frequency characteristics, e.g. single frequency signals, chirp signals (measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00)}
- G01N 29/42: by frequency filtering {or by tuning to resonant frequency}
- G01S 15/08: Systems for measuring distance only (indirect measurement G01S15/46)
- G01N 2291/0234: Metals, e.g. steel
- G01N 2291/02854: Length, thickness
- G01N 2291/0289: Internal structure, e.g. defects, grain size, texture
- G01N 2291/0422: Shear waves, transverse waves, horizontally polarised waves
- G01N 2291/0423: Surface waves, e.g. Rayleigh waves, Love waves
- G01N 2291/0426: Bulk waves, e.g. quartz crystal microbalance, torsional waves
- G01N 2291/044: Internal reflections (echoes), e.g. on walls or defects
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

## Abstract

The disclosure discloses a method, apparatus and system for detecting multi-mode electromagnetic acoustic and magnetic flux leakage and a sensor. The method comprises: S102, receiving an operation instruction for detecting an object to be detected, the operation instruction is used for controlling a detection sensor to enter into any one or more of working modes as follows: magnetic flux leakage detection, ultrasonic bulk wave detection, ultrasonic guided wave detection and surface wave detection; S104, controlling the detection sensor to output a corresponding detection signal according to the operation instruction; and S106, detecting the object to be detected on the basis of the detection signal. The technical solution achieves a purpose of using one sensor to realize various detection modes, such as magnetic flux leakage and electromagnetic acoustic modes, reduces complexity and cost of a detection system, and improves detection efficiency.

## Claims

### Claim 1

A method for detecting multi-mode electromagnetic acoustic and magnetic flux leakage, comprising:
receiving operation instruction for detecting an object to be detected, the operation instruction is used for controlling a detection sensor to enter any one or more of working modes as follows: magnetic flux leakage detection, ultrasonic bulk wave detection, ultrasonic guided wave detection and surface wave detection;
controlling the detection sensor to output a detection signal corresponding to the operation instruction according to the operation instruction;
detecting the object to be detected on the basis of the detection signal.

### Claim 2 (depends on 1)

The method as claimed in claim 1, wherein the detection sensor at least comprises a magnetic yoke, a magnetic flux leakage receiving component, a first electromagnetic acoustic coil below a pole N of the magnetic yoke and a second electromagnetic acoustic coil below a pole S of the magnetic yoke; the magnetic yoke is any one as follows: a permanent magnet or an electromagnet, an exciter field for detecting generating magnetic flux leakage and a bias magnetic field for electromagnetic acoustic detection.

### Claim 3 (depends on 2)

The method as claimed in claim 2, wherein the detection sensor generates a magnetic field signal inside the object to be detected trough the magnetic yoke under a condition of a working mode of magnetic flux leakage detection; detecting the object to be detected on the basis of the detection signal comprising:
detecting, by the magnetic flux leakage receiving component, whether a leakage magnetic field signal exists outside the object to be detected or not, and the magnetic flux leakage receiving component is positioned in the middle of the magnetic yoke;
confirming whether the object to be detected has defects according to a detection result.

### Claim 4 (depends on 2)

The method as claimed in claim 2, wherein controlling the detection sensor to output the corresponding detection signal according to the operation instruction under a condition of a working mode of ultrasonic bulk wave detection, comprising:
acquiring a first excitation signal for generating an ultrasonic bulk wave, the first excitation signal has a first frequency;
inputting the first excitation signal into the first electromagnetic acoustic coil or the second electromagnetic acoustic coil;
generating the ultrasonic bulk wave according to the first electromagnetic acoustic coil and the pole N of the magnetic yoke, or the second electromagnetic acoustic coil and the pole S of the magnetic yoke.

### Claim 5 (depends on 4)

The method as claimed in claim 4, wherein detecting the object to be detected on the basis of the detection signal under the condition of the working mode of ultrasonic bulk wave detection, comprising:
receiving a first echo signal reflected by the object to be detected to the ultrasonic bulk wave;
confirming whether the object to be detected has defects according to the first echo signal;
and/or confirming a thickness of the object to be detected according to the first echo signal.

### Claim 6 (depends on 2)

The method as claimed in claim 2, wherein controlling the detection sensor to output the corresponding detection signal according to the operation instruction under a condition of a working mode of ultrasonic guided wave detection, comprising:
acquiring a second excitation signal for generating an ultrasonic guided wave, the frequency of the second excitation signal is the second frequency;
inputting the second excitation signal into the first electromagnetic acoustic coil, or the second electromagnetic acoustic coil;
generating the ultrasonic guide wave according to the first electromagnetic acoustic coil and the pole N of the magnetic yoke, or the second electromagnetic acoustic coil or the pole S of the magnetic yoke.

### Claim 7 (depends on 6)

The method as claimed in claim 6, wherein detecting the object to be detected on the basis of the detection signal under the condition of the working mode of ultrasonic guided wave detection, comprising:
receiving a second echo signal reflected by the object to be detected to the ultrasonic bulk wave;
confirming whether the object to be detected has defects according to the second echo signal.

### Claim 8 (depends on 2)

The method as claimed in claim 2, wherein controlling the detection sensor to output the corresponding detection signal according to the operation instruction under a condition of a working mode of surface wave detection, comprising:
acquiring a third excitation signal for generating a surface wave, the third excitation signal has a third frequency;
inputting the third excitation signal into the first electromagnetic acoustic coil, or the second electromagnetic acoustic coil;
generating the surface wave according to the first electromagnetic acoustic coil and the pole N of the magnetic yoke, or the second electromagnetic acoustic coil and the pole S of the magnetic yoke.

### Claim 9 (depends on 8)

The method as claimed in claim 8, wherein detecting the object to be detected on the basis of the detection signal under the condition of the working mode of surface wave detection, comprising:
receiving, by the first electromagnetic acoustic coil, and/or the second electromagnetic acoustic coil, the surface wave from another electromagnetic acoustic coil;
confirming whether the object to be detected has defects according to energy of the surface wave.

### Claim 10 (depends on 8)

The method as claimed in claim 8, wherein detecting the object to be detected on the basis of the detection signal under the condition of the working mode of surface wave detection, comprising:
receiving, by the first electromagnetic acoustic coil, and/or the second electromagnetic acoustic coil, a first surface wave of the surface wave from another electromagnetic acoustic coil;
receiving, by the first electromagnetic acoustic coil, and/or the second electromagnetic acoustic coil, a second surface wave generated from the first electromagnetic acoustic coil and/or the second electromagnetic acoustic coil self;
confirming whether the object to be detected has defects according to energy of the first surface wave and the second surface wave.

### Claim 11

A multi-mode electromagnetic acoustic and magnetic flux leakage detection sensor, comprising:
a U-shaped magnetic yoke, configured to magnetize a material of an object to be detected, and generating a magnetic field signal in the object to be detected;
a magnetic flux leakage receiving component, positioned in the middle of the U-shaped magnetic yoke, and used for detecting whether a leakage magnetic field signal exists outside the object to be detected or not;
a first electromagnetic acoustic coil, positioned below a pole N of the U-shaped magnetic yoke, combined and used with a lower end of the pole N of the U-shaped magnetic yoke, and used for generating or receiving any one or more of multiple detection waves as follows: an ultrasonic bulk wave, an ultrasonic guided wave and a surface wave;
a second electromagnetic acoustic coil, positioned below a pole S of the U-shaped magnetic yoke, combined and used with a lower end of the pole S of the U-shaped magnetic yoke, and used for generating or receiving any one or more of multiple detection waves as follows: an ultrasonic bulk wave, an ultrasonic guided wave and a surface wave.

### Claim 12 (depends on 11)

The sensor as claimed in claim 11, wherein sizes of the first electromagnetic acoustic coil and the second electromagnetic acoustic coil meet equations as follows:
α=λR and d=(N+1/2)λR
where λR is a surface wave length, α is a distance of adjacent line sources, and d is a diameter of a coil on an innermost side of coils.

### Claim 13 (depends on 11)

The sensor as claimed in claim 11, wherein the magnetic flux leakage receiving component is a magnetic sensitive element.

### Claim 14 (depends on 13)

The sensor as claimed in claim 13, wherein the magnetic sensitive element is a Hall chip.

### Claim 15 (depends on 11)

The sensor as claimed in claim 11, further comprising: a magnetic flux leakage receiving component mounting base and a shell, the magnetic flux leakage receiving component mounting base is used for mounting the magnetic flux leakage receiving component; a spring is arranged between the magnetic flux leakage receiving component mounting base and the shell, so the magnetic flux leakage receiving component mounting base and the shell are in certain sliding.

### Claim 16 (depends on 11, 12, 13, 14, 15)

A system for detecting multi-mode electromagnetic acoustic and magnetic flux leakage, comprising: the sensor as claimed in any one of claims 11-15.

### Claim 17 (depends on 16)

The system as claimed in claim 16, further comprising:
a signal generator, for generating an excitation signal for the first electromagnetic acoustic coil and the second electromagnetic acoustic coil;
a power amplifier, connected with the signal generator, and used for amplifying the excitation signal.

### Claim 18 (depends on 17)

The system as claimed in claim 17, further comprising:
a duplexer, connected with the power amplifier, used for inputting the amplified excitation signal into the first electromagnetic acoustic coil and/or the second electromagnetic acoustic coil, and used for receiving an echo signal detected by the first electromagnetic acoustic coil and/or the second electromagnetic acoustic coil.

### Claim 19 (depends on 18)

The system as claimed in claim 18, further comprising:
a multi-channel signal acquirer, connected with the duplexer, used for receiving any one or more of signals as follows: the echo signal detected by the first electromagnetic acoustic coil, the echo signal detected by the second electromagnetic acoustic coil, and the leakage magnetic field signal detected by the magnetic flux leakage receiving component.

### Claim 20 (depends on 19)

The system as claimed in claim 19, further comprising:
a host computer, connected with the multi-channel signal acquirer, used for receiving a signal uploaded by the multi-channel signal acquirer, used for analyzing the signal, and used for confirming whether the object to be detected has defects according to an analysis result.

### Claim 21

(canceled)