US 2015/0177294 A1Published application

Method and device for processing magnetostrictive guided wave detection signals

AssigneeHuazhong University of Science and Technology

InventorsXinjun WU, Mingxi TANG, Pengfei SUN

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Abstract

A method for processing magnetostrictive guided wave detection signals, including: 1) obtaining an analysis signal by capturing an original magnetostrictive guided wave detection signal; 2) performing band-pass filtering on the analysis signal to obtain a signal, and initializing i to 0; 3) obtaining a group of signals x(i), x(i+1), . . . , x(i+M−1) using a rectangular window with a width of M; 4) forming a matrix A; 5) performing singular value decomposition on the matrix A to obtain a singular matrix B; 6) setting eigenvalues in the matrix B smaller than the median to 0 to obtain a matrix C, and performing inverse singular value transformation on the matrix C to obtain a matrix D; 7) recovering a group of processed signals from the matrix D and calculating energy z of the group of processed signals; and 8) setting i to (i+1) and repeating steps 3)-7) until i=N+1−M.

Claims4

Dependent claims

A method for processing magnetostrictive guided wave detection signals, the method comprising:

S1:
obtaining an analysis signal u(n) by capturing an original magnetostrictive guided wave detection signal, where n≦N, and N is the length of the analysis signal u(n);
S2:
performing band-pass filtering on the analysis signal u(n) to obtain a signal x(n), and initializing i to 0;
S3:
obtaining a group of signals x(i), x(i+1), . . . , x(i+M−1) using a rectangular window with a width of M, where M[L/4], and L is the length of the excitation signal;
S4:
forming a matrix A of R*(M−R+1), where R[M/2]:
A
=
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;
S5:
performing singular value decomposition on the matrix A to obtain a singular matrix B:
B
=
[
λ
1
0
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0
…
0
0
λ
2
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0
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0
0
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λ
R
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0
]
,
λj represents an eigenvalue, and j=1, 2, . . . R;
S6:
setting eigenvalues in the matrix B smaller than the median to 0 to obtain a matrix C, and performing inverse singular value transformation on the matrix C to obtain a matrix D:
D
=
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;
S7:
recovering a group of processed signals y(i), y(i+1), . . . , y(i+M−1) from the matrix D and calculating energy z of the group of processed signals;
and
S8:
setting i to (i+1) and repeating steps S3-S7 until i=N+1−M, whereby finishing calculation of energy of all processed signals in the selected analysis area.

213 more elements

A device for processing magnetostrictive guided wave detection signals, the device comprising:

1) a signal capturing unit, operable for capturing an original magnetostrictive guided wave detection signal to obtain an analysis signal u(n), where n≦N, and N is the length of the analysis signal u(n);
2) a band-pass filter, connected to the signal capturing unit and operable for performing band-pass filtering on the analysis signal u(n) to obtain a signal x(n);
and
3) a signal processing unit, connected to the band-pass filter and operable for denoising the signal x(n) and calculating the energy distribution of the denoised signal;
wherein the signal processing unit operates as follows:
a) obtaining a group of signals x(i), x(i+1), . . . , x(i+M−1) using a rectangular window with a width of M, where M[L/4], and L is the length of the excitation signal, and initializing i to 0;
b) forming a matrix A of R*(M−R+1), where R=[M/2]:
A
=
[
x

(
i
)
x

(
i
+
1
)
…
x

(
i
+
M
-
R
)
x
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(
i
+
1
)
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+
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…
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⋮
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⋱
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1
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x
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(
i
+
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i
+
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]
;
c) performing singular value decomposition on the matrix A to obtain a singular matrix B:
B
=
[
λ
1
0
…
0
…
0
0
λ
2
…
0
…
0
⋮
⋮
⋱
⋮
⋮
⋮
0
0
…
λ
R
…
0
]
,
λj represents an eigenvalue, and j=1, 2, . . . R;
d) setting eigenvalues in the matrix B smaller than the median to 0 to obtain a matrix C, and performing inverse singular value transformation on the matrix C to obtain a matrix D:
D
=
[
y

(
i
)
y
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(
i
+
1
)
…
y
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(
i
+
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-
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i
+
1
)
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+
2
)
…
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⋮
⋮
⋱
⋮
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y
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(
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+
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)
…
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(
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+
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-
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]
;
e) recovering a group of processed signals y(i), y(i+1), . . . , y(i+M−1) from the matrix D and calculating energy z of the group of processed signals;
and
f) setting i to (i+1) and repeating the steps of obtaining a group of signals x(i), x(i+1), . . . , x(i+M−1) using a rectangular window with a width of M and processing the signals until i=N+1−M, whereby finishing calculation of energy of all processed signals in the selected analysis area.

208 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/538,787Filed 11 Nov 2014
Priority: CN 201310723746.024 Dec 2013
Published: 25 Jun 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

G01R 21/133
Arrangements for measuring electric power or power factor: by using digital technique
G01M 99/00
Subject matter not provided for in other groups of this subclass
G01N 29/2412
Probes: using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]
G01N 29/42
Detecting the response signal , e.g. electronic circuits specially adapted therefor: by frequency filtering or by tuning to resonant frequency

Family

Application14/538,787Continuation in part
US 2015/0177294 A1This patent

From the US filing history. Foreign family members aren’t listed.

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