U.S. patent application number 16/416011 was filed with the patent office on 2020-11-19 for fiber bragg grating's inclinometer.
The applicant listed for this patent is Li SUN, Chunwei ZHANG. Invention is credited to Cuipeng GU, Chuang LI, Tianqi LIANG, Zhongxin SU, Li SUN, Chunwei ZHANG.
Application Number | 20200363200 16/416011 |
Document ID | / |
Family ID | 1000004257656 |
Filed Date | 2020-11-19 |
United States Patent
Application |
20200363200 |
Kind Code |
A1 |
ZHANG; Chunwei ; et
al. |
November 19, 2020 |
Fiber Bragg Grating's inclinometer
Abstract
A fiber Bragg grating inclination sensor, including a
semicircular substrate and a packaged fiber Bragg grating. The
semicircular substrate is fixed on a first structural member. One
endpoint of the semicircular substrate is bonded with one end of
the packaged fiber Bragg grating, and the other end of the packaged
fiber Bragg grating is connected to a second structural member. The
first structural member is fixed to the second structural member
perpendicular to the first structural member. The packaged fiber
Bragg grating is arranged on a tangent to the semicircular
substrate. The fiber Bragg grating sensor of the present invention
has the advantages of anti-electromagnetic interference and high
sensitiveness. The present invention has a simple structure, high
measurement accuracy, good stability, thereby having broad
application prospects.
Inventors: |
ZHANG; Chunwei; (Qingdao,
CN) ; SUN; Li; (Shenyang, CN) ; LI;
Chuang; (Shenyang, CN) ; SU; Zhongxin;
(Shenyang, CN) ; GU; Cuipeng; (Shenyang, CN)
; LIANG; Tianqi; (Shenyang, CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ZHANG; Chunwei
SUN; Li |
Qingdao
Shenyang |
|
CN
CN |
|
|
Family ID: |
1000004257656 |
Appl. No.: |
16/416011 |
Filed: |
May 17, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01C 9/00 20130101; G01D
5/35316 20130101; G01C 9/06 20130101; G01M 11/085 20130101; G01C
2009/066 20130101; G01B 11/26 20130101 |
International
Class: |
G01C 9/06 20060101
G01C009/06 |
Claims
1. A fiber Bragg grating inclination sensor, comprising: a first
structural member, a second structural member, a semicircular
substrate, and a packaged fiber Bragg grating; wherein the
semicircular substrate is fixed on the first structural member, and
one endpoint of the semicircular substrate is bonded with one end
of the packaged fiber Bragg grating; the other end of the packaged
fiber Bragg grating is connected to the second structural member;
the first structural member is fixed to the second structural
member perpendicular to the first structural member; and the
packaged fiber Bragg grating is arranged on a tangent to the
semicircular substrate.
2. The fiber Bragg grating inclination sensor of claim 1, wherein a
lower portion of the semicircular substrate is provided with a
fixing flange; and the first structural member is provided with a
recess to fix the fixing flange.
3. The fiber Bragg grating inclination sensor of claim wherein the
semicircular substrate is made of Q235 steel.
4. The fiber Bragg grating inclination sensor of claim 1, wherein
an adhesive for the packaged fiber Bragg grating is 353ND.
5. The fiber Bragg grating inclination sensor of claim 1, wherein a
bottom surface of the semicircular substrate is bonded onto a.
surface of the first structural member.
Description
TECHNICAL FIELD
[0001] The present application relates to fiber Bragg grating
sensing and monitoring, and more particular to a fiber Bragg
grating inclination sensor.
BACKGROUND OF THE INVENTION
[0002] Differential settlement of foundations will severely and
adversely affect house structures, which may cause global or local
inclination of the structure, and structural cracking may occur as
the result of a large local inclination. Therefore, monitoring the
inclination of structural members is of great importance. The
conventional inclination sensors are mainly electrical sensors, and
the signal is susceptible to interference, thereby causing low
accuracy.
SUMMARY OF THE INVENTION
[0003] The present application relates to a fiber Bragg grating
inclination sensor.
[0004] The technical solutions of the present invention are as
follows.
[0005] A fiber Bragg grating inclination sensor comprises a first
structural member, a second structural member, a semicircular
substrate, and a packaged fiber Bragg grating.
[0006] The semicircular substrate is fixed on the first structural
member, and one endpoint of the semicircular substrate is bonded
with one end of the packaged fiber Bragg grating.
[0007] The other end of the packaged fiber Bragg grating is
connected to the second structural member. The first structural
member is fixed to the second structural member perpendicular to
the first structural member.
[0008] The packaged fiber Bragg grating is arranged on a tangent to
the semicircular substrate.
[0009] The present invention has the following benefits.
[0010] 1. The fiber Bragg grating sensor of the present invention
has the advantages of anti-electromagnetic interference, high
sensitiveness and high accuracy.
[0011] 2. The present invention has a simple structure, high
measurement accuracy, good stability, thereby having broad
application prospects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic diagram of a fiber Bragg grating
inclination sensor of the present invention.
[0013] FIG. 2 is a top view of the fiber Bragg grating inclination
sensor of the present invention.
[0014] FIG. 3 is a perspective view of a semicircular substrate of
the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
[0015] The present invention will be further described in detail
below with reference to the accompanying drawings.
[0016] A fiber Bragg grating inclination sensor, comprising a first
structural member 3, a second structural member 4, a semicircular
substrate 1, and a packaged fiber Bragg grating 2.
[0017] The semicircular substrate 1 is fixed on the first
structural member 3, and one endpoint of the semicircular substrate
1 is bonded with one end of the packaged fiber Bragg grating 2.
[0018] The other end of the packaged fiber Bragg grating 2 is
connected to the second structural member 1. The first structural
member 3 is fixed to the second structural member 4 perpendicular
to the first structural member 3.
[0019] The packaged fiber Bragg grating 2 is arranged on a tangent
to the semicircular substrate 1.
[0020] A lower portion of the semicircular substrate 1 is provided
with a fixing flange 11; the first structural member 3 is provided
with a recess 31 to fix the fixing flange.
[0021] The semicircular substrate is made of Q235 steel.
[0022] An adhesive for the packaged fiber Bragg grating is
353ND.
[0023] A bottom surface of the semicircular substrate is bonded
onto a surface of the first structural member.
[0024] Working principle of the present invention is as
follows.
[0025] When the semicircular substrate 1 is rotated, .theta. is the
inclination angle, and R is the radius of the semicircular
structure. Referring to FIG. 2,
L.sub.AM'=L.sub.1 (1)
[0026] where L.sub.AM and L.sub.1 each are the initial length of a
sensor of the packaged fiber Bragg grating 2;
L AM ' = L 1 + ( .DELTA..lamda. B K ) .times. L 1 ( 2 )
##EQU00001##
[0027] where L.sub.AM' is the changed length of the packaged fiber
Bragg grating 2;
.theta.=2.alpha. (3)
[0028] .theta. is the central angle, and .alpha. is the
circumferential angle;
L.sub.MM'=2R.times.sin (.theta./2) (4)
[0029] According to the law of cosines,
cos .alpha. = L AM ' 2 + L AM 2 - L MM ' 2 2 .times. L AM ' .times.
L AM ( 5 ) ##EQU00002##
[0030] plug (3) and (4) into (5),
cos ( .theta. 2 ) = L AM .times. L AM ' - ( 4 R 2 - L AM 2 )
.times. ( 4 R 2 - L AM ' 2 ) 2 4 R 2 ( 6 ) .theta. = 2 arc cos L AM
.times. L AM ' - ( 4 R 2 - L AM 2 ) .times. ( 4 R 2 - L AM ' 2 ) 2
4 R 2 ( 7 ) ##EQU00003##
[0031] where R is the radius;
[0032] and plug (1) and (2) into (7),
.theta. = 2 arc cos L 1 2 .times. ( 1 + .DELTA..lamda. B K ) - ( 2
R + L 1 ) .times. ( 2 R - L 1 ) .times. [ 2 R + L 1 .times. ( 1 +
.DELTA..lamda. B K ) ] .times. [ 2 R - L 1 .times. ( 1 +
.DELTA..lamda. B K ) ] 4 R 2 . ( 8 ) ##EQU00004##
[0033] This equation gives a theoretical relationship between the
inchnation angle .theta. and the wavelength change
.DELTA..lamda..sub.B. By demodulating the wavelength change of the
sensor of the packaged fiber Bragg grating 2, a change value of the
inclination angle of the semicircular substrate 1 is obtained,
realizing a real-time online monitoring of the structural
inclination.
* * * * *