阅读说明：本技术 一种光纤环结构及光纤环模拟测温结构 (Optical fiber ring structure and optical fiber ring simulation temperature measurement structure ) 是由 岑礼君 于 2020-12-25 设计创作，主要内容包括：本发明提供一种光纤环结构及光纤环模拟测温结构,光纤环结构为空心柱状结构且包括在光纤环长度方向上设置的M层光纤,M≥2,其特征在于,光纤环结构包括L根光纤,L≥1,第i根光纤绕设形成在光纤环结构长度方向布置的M-i层光纤,光纤环结构每层光纤上光纤的匝数为N,每匝光纤均围成具有K个边的正多边形；光纤环结构每层光纤上均设置有至少3个布拉格光栅传感器,光纤环结构每层光纤上各个布拉格光栅传感器围成的图形为关于光纤环结构中心轴对称的图形,各个布拉格光栅传感器均设置于正多边形的边上。(The invention provides an optical fiber ring structure and an optical fiber ring simulation temperature measurement structure, wherein the optical fiber ring structure is a hollow columnar structure and comprises M layers of optical fibers arranged in the length direction of the optical fiber ring, M is more than or equal to 2, the optical fiber ring structure is characterized by comprising L optical fibers, L is more than or equal to 1, and the ith optical fiber is wound to form M optical fibers arranged in the length direction of the optical fiber ring structure i The number of turns of the optical fibers on each layer of the optical fiber ring structure is N, and each turn of the optical fibers is enclosed into a regular polygon with K sides; all be provided with 3 at least bragg grating sensors on every layer of optic fibre ring structure, the figure that each bragg grating sensor encloses on every layer of optic fibre ring structure is the figure about optic fibre ring structure central axis symmetry, and each bragg grating sensor all sets up in regular polygon's edge.)

1. The optical fiber ring structure is characterized in that the optical fiber ring structure (4) comprises L optical fibers, L is larger than or equal to 1, and the ith optical fiber is wound on the M optical fibers arranged in the length direction of the optical fiber ring structure (4)_iThe number of turns of the optical fibers on each layer of optical fiber of the optical fiber ring structure (4) is N, and M is more than or equal to 2_iNot more than 10, N not less than 5, each turn of optical fiber is enclosed into a regular polygon with K sides, K not less than 6, i =1,2, … …, L;

when L is more than or equal to 2, M₁Layer optical fiber, M₂Laminated optical fiber, … …, M_LThe optical fibers are arranged in sequence in the length direction of the optical fiber ring structure (4), thereby forming M layers of optical fibers arranged in the length direction of the optical fiber ring, M₁+M₂+……+M_L=M；

The optical fiber ring structure is characterized in that at least 3 Bragg grating sensors (41) are arranged on each layer of optical fiber of the optical fiber ring structure (4), a figure formed by surrounding of the Bragg grating sensors (41) on each layer of optical fiber of the optical fiber ring structure (4) is a figure symmetrical about the central axis of the optical fiber ring structure (4), and the Bragg grating sensors (41) are arranged on the edge of a regular polygon.

2. The fiber optic ring structure of claim 1, wherein: defining that the innermost circle of optical fiber and the outermost circle of optical fiber in each layer of optical fiber of the optical fiber ring structure (4) are the 1 st circle of optical fiber and the Nth circle of optical fiber respectively;

the Nth layer of each layer of optical fiber of the optical fiber ring structure (4)₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth_SThe turn of the optical fiber is provided with the Bragg grating sensor (41); when N is an even number, S is more than or equal to 2 and less than or equal to N/2, and when N is an odd number, S is more than or equal to 2 and less than or equal to (N + 1)/2; 2 is less than or equal to (N)_j+1-N_j)≤10，(N₂-N₁)= (N₃-N₂)=……=(N_S-N_S-1)，1≤j≤S-1。

3. The fiber optic ring structure of claim 2, wherein: k is an even number, and the Nth layer of each layer of optical fibers of the optical fiber ring structure (4)₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth_SK/2 Bragg grating sensors (41) are respectively arranged on K/2 sides which are not adjacent on each circle of optical fiber in the circle of optical fiber.

4. The fiber ring structure of claim 3, wherein: the optical fiber ring structure (4) is arranged in the Nth layer of the upper layer of two adjacent layers of optical fibers_jK/2 edges where K/2 Bragg grating sensors (41) arranged on the turn optical fiber are positioned and the Nth edge positioned at the lower layer_jK/2 sides where K/2 Bragg grating sensors (41) arranged on the turn optical fiber are located are arranged in a staggered mode in the length direction of the optical fiber ring structure (4).

5. The fiber ring structure of claim 3, wherein: n th_j+1Among the K sides of the turn of optical fiber,and N_jK/2 Bragg grating sensors (41) are respectively arranged on K/2 sides except K/2 sides corresponding to K/2 sides of the Bragg grating sensors (41) arranged on the turn optical fiber.

6. The fiber optic ring structure of claim 1, wherein: the lengths of the individual fibers being equal, M₁=M₂=……=M_L；

Preferably, L =4, M₁=M₂=M₃=M₄=5，N=40；

More preferably, the Nth optical fiber of each layer of optical fibers of the optical fiber ring structure (4)₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth₄Turn of optical fiber is provided with the Bragg grating sensor (41), (N)_j+1-N_j)=10，1≤j≤3。

7. The fiber optic ring structure of claim 1, wherein: k = 8.

8. An optical fiber ring simulation temperature measurement structure comprises a wide-spectrum light source (5), a coupler (9), a filter (7), a photoelectric detector (8) and a signal processing module (10), wherein the coupler (9) is provided with an input end, a first output end and a second output end, the input end and the first output end of the coupler (9) are respectively and correspondingly connected with the output end of the wide-spectrum light source (5) and one end of the narrow-band filter (7), and two ends of the photoelectric detector (8) are respectively and correspondingly connected with the other end of the narrow-band filter (7) and the input end of the signal processing module (10);

the optical fiber ring temperature simulation structure is characterized by further comprising the optical fiber ring structure (4) as claimed in any one of claims 1 to 7, wherein the sum of the lengths of the optical fibers is equal to the length of the simulated optical fiber ring;

when L =1, one end of 1 optical fiber is connected with the second output end of the coupler (9);

when L is larger than or equal to 2, one end of each optical fiber is connected with the second output end of the coupler (9) in a switchable manner.

9. The analog temperature measurement structure of the optical fiber ring of claim 8, wherein: l is more than or equal to 2, the optical fiber ring simulation temperature measurement structure further comprises an optical switch array (6) with at least L switches, and two ends of the ith switch of the optical switch array (6) are respectively connected with the second output end of the coupler (9) and one end of the ith optical fiber.

10. The analog temperature measurement structure of the optical fiber ring of claim 9, wherein: the optical fiber ring simulation temperature measurement structure also comprises a box body for accommodating the optical fiber ring simulation temperature measurement structure, a structure body (1) is arranged in the box body, and the optical fiber ring structure (4) is wound on the outer wall surface of the structure body (1);

a wide-spectrum light source (5) and a signal processing module (10) are arranged on one side of the structure body (1) in the length direction of the optical fiber ring structure (4);

the other side of the structure body (1) in the length direction of the optical fiber ring structure (4) is provided with an optical switch array (6), a narrow-band filter (7), a photoelectric detector (8) and a coupler (9);

preferably, the other side of the structure body (1) in the length direction of the optical fiber ring structure (4) is provided with a first groove and a second groove which are used for accommodating the optical switch array (6) and the photoelectric detector (8) respectively.

Technical Field

The invention belongs to the technical field of fiber optic inertial navigation, and provides a novel fiber optic ring simulation temperature measurement structure based on fiber bragg gratings, which is applied to the simulation measurement of the temperature of a fiber optic ring of a fiber optic gyroscope.

Background

The optical fiber ring is an important element in the optical fiber gyroscope and is used for sensing angular rate, when the optical fiber ring rotates along the axial direction, two optical signals which are oppositely transmitted in the optical fiber ring reach the same point to generate a Sagnac phase difference, the two optical waves are different in phase change (namely Shupe effect) caused by temperature change after passing through the optical fiber ring, the Shupe effect seriously influences the precision of the optical fiber gyroscope, a temperature compensation method is needed in the high-precision optical fiber gyroscope to reduce zero offset drift caused by the Shupe effect, and in order to achieve the optimal temperature compensation effect, the temperature distribution condition of the whole optical fiber ring needs to be accurately measured.

In the prior art, temperature measurement equipment is generally used to measure the temperature distribution of the fiber loop outside the fiber loop. However, the existing temperature measuring device can only measure the temperature distribution of the outer edge and the inner edge of the optical fiber ring in the length direction of the optical fiber ring, but cannot measure the temperature distribution condition inside the optical fiber ring, and when the number of turns (turns) of the optical fiber ring in the optical fiber gyroscope is large (for example, dozens of turns are wound), the existing temperature measuring device cannot measure the temperature of the middle position far away from the inner edge and the outer edge of the optical fiber ring, so that the temperature distribution condition of the optical fiber ring reflected by the measuring result of the temperature measuring device is very one-sided, and the subsequent temperature compensation effect is greatly influenced.

Disclosure of Invention

The invention provides an optical fiber ring structure aiming at the problem that the temperature distribution condition of an optical fiber ring reflected by the measurement result of the existing temperature measurement equipment is very unilateral, and further the subsequent temperature compensation effect is greatly influenced.

In order to solve the problems, the technical scheme adopted by the invention is as follows: an optical fiber ring structure is a hollow cylindrical structure and comprises M layers of optical fibers arranged in the length direction of the optical fiber ring, wherein M is more than or equal to 2, the optical fiber ring structure comprises L optical fibers, L is more than or equal to 1, and the ith optical fiber is wound on the M layers of optical fibers arranged in the length direction of the optical fiber ring structure_iThe number of turns of the optical fibers on each layer of optical fiber of the optical fiber ring structure is N, 2 is less than or equal to M_iNot more than 10, N not less than 5, each turn of optical fiber is enclosed into a regular polygon with K sides, K not less than 6, i =1,2, … …, L;

when L is more than or equal to 2, M₁Layer optical fiber, M₂Laminated optical fiber, … …, M_LThe layer optical fibers are sequentially arranged in the length direction of the optical fiber ring structure, so that M layers of optical fibers arranged in the length direction of the optical fiber ring are formed, and M is₁+M₂+……+M_L=M；

The optical fiber ring structure is characterized in that at least 3 Bragg grating sensors are arranged on each layer of optical fiber, a figure formed by surrounding of the Bragg grating sensors on each layer of optical fiber is symmetrical about the central axis of the optical fiber ring structure, and the Bragg grating sensors are arranged on the sides of the regular polygon.

In the invention, the applicant finds that the optical fiber ring structure in the optical fiber gyroscope is annular, but the Bragg grating sensor for measuring temperature cannot be bent. In order to simulate the real working condition of the optical fiber ring as much as possible, the optical fiber ring is enclosed into a regular polygon structure with at least 6 sides, so that the Bragg grating sensors can be arranged on the sides of the regular polygon. Because the regular polygon structure with at least 6 sides is similar to a circle, the regular polygon structure can be similar to the structure of an optical fiber ring with a circular actual section, so that the temperature simulation structure is smaller than the actual optical fiber ring in difference. In addition, because the wavelength range of the light source in the fiber-optic gyroscope is limited, the wavelength ranges occupied by the bragg grating sensors which need to measure the temperature need to be distinguished, and if the temperature measurement resolution is to be ensured, too many bragg grating sensors cannot be arranged. Therefore, in the application, more than two optical fibers can be adopted to jointly form M layers of optical fibers arranged in the length direction of the optical fiber ring, one of the optical fibers can be independently connected to an optical path, the temperature can be measured by utilizing each Bragg grating sensor arranged on the optical fiber, and each Bragg grating sensor can still occupy a proper wavelength range due to the fact that only the wavelength ranges occupied by the Bragg grating sensors on one optical fiber need to be distinguished, so that the temperature measurement resolution is guaranteed. The optical fiber ring temperature distribution condition of the optical fiber ring formed by the L optical fibers can be obtained by sequentially connecting each optical fiber into the optical path, measuring the temperature of the position of the Bragg grating sensor on one optical fiber at a time and combining the temperature measurement results on each optical fiber. Because the graph surrounded by the Bragg grating sensors on each layer of optical fiber is a graph symmetrical about the central axis of the optical fiber ring structure, the temperature measuring points are uniformly distributed.

Further, defining that the innermost circle of optical fiber and the outermost circle of optical fiber in each layer of optical fiber of the optical fiber ring structure are the 1 st circle of optical fiber and the Nth circle of optical fiber respectively;

nth optical fiber of each layer of optical fiber ring structure₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth_SThe turn optical fiber is provided with the Bragg grating sensor; when N is an even number, S is more than or equal to 2 and less than or equal to N/2, and when N is an odd number, S is more than or equal to 2 and less than or equal to (N + 1)/2; 2 is less than or equal to (N)_j+1-N_j)≤10，(N₂-N₁)= (N₃-N₂)=……=(N_S-N_S-1)，1≤j≤S-1。

In the invention, the Bragg grating sensors can be uniformly arranged from the innermost side to the outermost side in each layer of optical fiber through the arrangement.

Further, K is even number, and the Nth layer of the optical fiber of each layer of the optical fiber ring structure₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth_SK/2 Bragg grating sensors are respectively arranged on K/2 sides which are not adjacent on each turn of optical fiber in the turn of optical fiber.

According to the invention, through the arrangement, the Bragg grating sensors can be uniformly arranged on each circle of optical fiber, so that the temperature distribution characteristic of the optical fiber ring structure is well reflected.

Furthermore, the optical fiber ring structure is positioned in the Nth layer of the upper layer of the two adjacent layers of optical fibers_jK/2 edges where K/2 Bragg grating sensors arranged on turn optical fibers are located and Nth edge located on lower layer_jK/2 edges where K/2 Bragg grating sensors arranged on the turn optical fiber are located are arranged in a staggered mode in the length direction of the optical fiber ring structure.

In the invention, the first layer and the second layer are arranged in the upper layer_jThe Bragg grating sensor arranged on the turn of optical fiber enables the distribution range of the temperature measuring points to be larger, and the temperature measuring points can cover a larger area of the optical fiber ring.

Further, N (th)_j+1Among K sides of the turn of the optical fiber, and N_jK/2 Bragg grating sensors are respectively arranged on K/2 sides of the turn optical fiber, which are not K/2 sides corresponding to the K/2 sides of the Bragg grating sensors.

In the invention, by making the Nth_jTurn optical fiber, Nth_j+1The Bragg grating sensors arranged on the turn optical fiber are arranged in a staggered mode, so that the distribution range of the temperature measuring points is larger, and the temperature measuring points can cover a larger area of the optical fiber ring.

Further, the lengths of the respective optical fibers are the same, M₁=M₂=……=M_L；

Preferably, L =4, M₁=M₂=M₃=M₄=5，N=40；

More preferably, the Nth optical fiber of each layer of optical fibers of the optical fiber ring structure₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth₄The turn optical fiber is provided with the Bragg grating sensor (N)_j+1-N_j)=10，1≤j≤3。

Further, K = 8.

The applicant finds that, when the number of sides of the regular polygon is larger, the regular polygon is closer to the circular cross section of the simulated optical fiber ring structure, but the winding difficulty of the optical fiber is increased, and the bragg grating sensor needs a certain arrangement space, so that the side length of the regular polygon is required to reach a certain length, and therefore, K =8 is a preferable technical scheme in consideration of comprehensive balance.

The invention also provides an optical fiber ring simulation temperature measurement structure, which comprises a wide-spectrum light source, a coupler, a filter, a photoelectric detector and a signal processing module, wherein the coupler is provided with an input end, a first output end and a second output end;

the optical fiber ring simulation temperature measurement structure further comprises the optical fiber ring structure, wherein the sum of the lengths of all optical fibers is equal to the length of the simulated optical fiber ring;

when L =1, one end of 1 optical fiber is connected with the second output end of the coupler;

when L is larger than or equal to 2, one end of each optical fiber is connected with the second output end of the coupler in a switchable manner.

In the invention, more than two optical fibers are adopted to form M layers of optical fibers arranged in the length direction of the optical fiber ring together, and the sum of the lengths of the optical fibers is equal to the length of the simulated optical fiber ring. When in measurement, one of the optical fibers is independently connected to an optical path, and the Bragg grating sensors arranged on the optical fiber are used for measuring the temperature, and because the wavelength ranges occupied by the Bragg grating sensors on one optical fiber only need to be distinguished, each Bragg grating sensor can still occupy a proper wavelength range, thereby ensuring the temperature measurement resolution. The optical fiber ring temperature distribution condition of the optical fiber ring formed by the L optical fibers can be obtained by sequentially connecting each optical fiber into the optical path, measuring the temperature of the position of the Bragg grating sensor on one optical fiber at a time and combining the temperature measurement results on each optical fiber. Because the graph surrounded by the Bragg grating sensors on each layer of optical fiber is a graph symmetrical about the central axis of the optical fiber ring structure, the temperature measuring points are uniformly distributed.

Furthermore, L is more than or equal to 2, the optical fiber ring simulation temperature measurement structure further comprises an optical switch array with at least L switches, and two ends of the ith switch of the optical switch array are respectively connected with the second output end of the coupler and one end of the ith optical fiber.

In the invention, by arranging the optical switch array, which optical fiber is connected into the optical path can be controlled.

Furthermore, the optical fiber ring simulation temperature measurement structure also comprises a box body for accommodating the optical fiber ring simulation temperature measurement structure, a structure body is arranged in the box body, and the optical fiber ring structure is wound on the outer wall surface of the structure body;

the structure body is provided with a wide-spectrum light source and a signal processing module at one side in the length direction of the optical fiber ring structure;

the other side of the structure body in the length direction of the optical fiber ring structure is provided with an optical switch array, a narrow-band filter, a photoelectric detector and a coupler;

preferably, the other side of the structure body in the length direction of the optical fiber ring structure is provided with a first groove and a second groove which are used for accommodating the optical switch array and the photoelectric detector respectively.

The invention has the advantages that the temperature value of each node of the annular structure can be accurately measured in real time by adopting a distributed fiber bragg grating temperature measurement mode, so that the temperature value of each node of the fiber optic ring is approximately simulated, the traditional temperature compensation mode based on external temperature and temperature change rate is greatly optimized, and the precision of the fiber optic gyroscope after temperature compensation is improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive labor.

Fig. 1 is a schematic perspective view of an optical fiber ring structure according to an embodiment of the present invention;

FIG. 2 is a schematic top view of one of the layers of optical fibers of FIG. 1;

FIG. 3 is a schematic illustration of the distribution of Bragg grating sensors on two adjacent layers of the optical fiber of FIG. 1;

FIG. 4 is a schematic side view of FIG. 1;

FIG. 5 is a schematic diagram of an optical path and an electrical circuit of a fiber ring analog temperature measurement structure according to an embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view of the arrangement position of the optical fiber ring analog temperature measurement structure according to the embodiment of the present invention.

In the attached drawings, the structure comprises a structure body 1, a bottom plate 2, an outer cover 3, an optical fiber ring structure 4, a Bragg grating sensor 41, a wide spectrum light source 5, an optical switch array 6, a filter 7, a photoelectric detector 8, a coupler 9, a signal processing module 10 and a light source driving plate 11.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The invention provides an optical fiber ring structure, wherein the optical fiber ring structure 4 is a hollow cylindrical structure and comprises M layers of optical fibers arranged in the length direction of the optical fiber ring, M is more than or equal to 2, the optical fiber ring structure 4 comprises L optical fibers, L is more than or equal to 1, and the ith optical fiber is wound around the M layers of optical fibers arranged in the length direction of the optical fiber ring structure 4_iThe number of turns of the optical fibers on each layer of the optical fiber ring structure 4 is N, and M is not less than 2_iNot more than 10, N not less than 5, each turn of optical fiber is enclosed into a regular polygon with K sides, K not less than 6, i =1,2, … …, L;

when L is more than or equal to 2, M₁Layer optical fiber, M₂Laminated optical fiber, … …, M_LThe layer optical fibers are sequentially arranged in the length direction of the optical fiber ring structure 4, so that M layers of optical fibers arranged in the length direction of the optical fiber ring are formed, wherein M is the number of the optical fibers₁+M₂+……+M_L=M；

Each layer of optical fiber of the optical fiber ring structure 4 is provided with at least 3 bragg grating sensors 41, the pattern surrounded by the bragg grating sensors 41 on each layer of optical fiber of the optical fiber ring structure 4 is a pattern symmetrical about the central axis of the optical fiber ring structure 4, and each bragg grating sensor 41 is arranged on the edge of a regular polygon.

In a preferred technical scheme of the optical fiber ring structure, the innermost circle of optical fibers and the outermost circle of optical fibers in each layer of optical fibers of the optical fiber ring structure 4 are defined as 1-turn optical fibers and Nth-turn optical fibers respectively;

the Nth layer of each layer of optical fiber of the optical fiber ring structure 4₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth_SThe turn optical fiber is provided with the Bragg grating sensor 41; when N is an even number, S is more than or equal to 2 and less than or equal to N/2, and when N is an odd number, S is more than or equal to 2 and less than or equal to (N + 1)/2; 2 is less than or equal to (N)_j+1-N_j)≤10，1≤j≤s-1。

In a preferred embodiment of the optical fiber ring structure, K is an even number, and in each layer of optical fibers of the optical fiber ring structure 4, the nth layer₁K/2 Bragg gratings are respectively arranged on K/2 sides of the non-adjacent turn optical fiberSensor 41, Nth₂K/2 Bragg grating sensors 41 and … … are respectively arranged on K/2 sides of the non-adjacent turns of the optical fiber_SK/2 Bragg grating sensors 41 are respectively arranged on K/2 sides of the non-adjacent turns of the optical fiber.

In a preferred technical solution of the optical fiber ring structure, the nth layer of the two adjacent layers of optical fibers of the optical fiber ring structure 4 is located at the upper layer_jK/2 sides where K/2 Bragg grating sensors 41 arranged on turn optical fibers are positioned and Nth side positioned on lower layer_jK/2 sides where K/2 Bragg grating sensors 41 arranged on the turn optical fiber are located are arranged in a staggered mode in the length direction of the optical fiber ring structure 4.

In a preferred embodiment of the optical fiber ring structure, the Nth optical fiber_j+1Among K sides of the turn of the optical fiber, and N_jK/2 Bragg grating sensors 41 are respectively arranged on K/2 sides except K/2 sides corresponding to the K/2 sides of the Bragg grating sensor 41 arranged on the turn optical fiber.

In a preferred embodiment of the fiber ring structure, the individual fibers have the same length, M₁=M₂=……=M_L。

In a further preferred embodiment of the fiber ring structure, L =4, M₁=M₂=M₃=M₄=5，N=40。

In a further preferred embodiment of the optical fiber ring structure, the nth layer of optical fibers of each layer of the optical fiber ring structure 4₁Turn optical fiber, Nth₂Turn optical fiber … …, Nth₄The turn of the optical fiber is provided with the Bragg grating sensor 41 (N)_j+1-N_j)=10，1≤j≤3。

The invention also provides an optical fiber ring simulation temperature measurement structure, which comprises a wide-spectrum light source 5, a coupler 9, a filter 7, a photoelectric detector 8 and a signal processing module 10, wherein the coupler 9 is provided with an input end, a first output end and a second output end, the input end and the first output end of the coupler 9 are respectively and correspondingly connected with the output end of the wide-spectrum light source 5 and one end of the narrow-band filter 7, and two ends of the photoelectric detector 8 are respectively and correspondingly connected with the other end of the narrow-band filter 7 and the input end of the signal processing module 10;

the optical fiber ring simulation temperature measurement structure is characterized by further comprising the optical fiber ring structure 4 as claimed in any one of claims 1 to 7, wherein the sum of the lengths of the optical fibers is equal to the length of the simulated optical fiber ring;

when L =1, one end of 1 optical fiber is connected to the second output end of the coupler 9;

when L is larger than or equal to 2, one end of each optical fiber is connected with the second output end of the coupler 9 in a switchable manner.

In a preferred technical scheme of the optical fiber ring analog temperature measurement structure, L is more than or equal to 2, the optical fiber ring analog temperature measurement structure further comprises an optical switch array 6 with at least L switches, and two ends of the ith switch of the optical switch array 6 are respectively connected with the second output end of the coupler 9 and one end of the ith optical fiber.

In a preferred technical scheme of the optical fiber ring simulation temperature measurement structure, the optical fiber ring simulation temperature measurement structure further comprises a box body for accommodating the optical fiber ring simulation temperature measurement structure, a structure body 1 is arranged in the box body, and an optical fiber ring structure 4 is wound on the outer wall surface of the structure body 1;

a wide-spectrum light source 5 and a signal processing module 10 are arranged on one side of the structure body 1 in the length direction of the optical fiber ring structure 4;

the other side of the structure body 1 in the length direction of the optical fiber ring structure 4 is provided with an optical switch array 6, a narrow-band filter 7, a photoelectric detector 8 and a coupler 9.

The filter 7 is preferably a narrow band filter, more preferably a tunable narrow band filter.

The structural body 1 is made of an aluminum alloy. The box body is enclosed by a bottom plate 2 and an outer cover 3. The bottom plate 2 is positioned below the structure body 1, and the outer cover 3 is wrapped on the periphery and the upper part of the structure body 1 and is connected with the bottom plate 2 through screws.

The optical path structure includes: a fiber ring structure 4 (also called a grating simulation ring), a wide spectrum light source 5, an optical switch array 6, a tunable narrow-band filter, a photoelectric detector 8, a coupler 9 and a connection tail fiber. The grating simulation ring, the wide-spectrum light source, the optical switch array, the tunable narrow-band filter, the photoelectric detector and the coupler are connected through the fusion of connecting tail fibers. The optical fiber ring structure 4 and the wide-spectrum light source 5 are arranged below the structure body 1. The tunable narrow-band filter is used for reducing the noise of an optical path and improving the temperature measurement accuracy.

The optical switch driving device starts the optical switch array 6 to control the on-off of the multi-path optical fiber(s). The optical switch array 6 controls the on-off of 4 paths of fiber gratings (4 optical fibers) so as to achieve the purpose of distributed measurement.

The optical switch array 6, the tunable narrow-band filter, the photoelectric detector 8 and the coupler 9 are arranged above the structural body 1.

The wide-spectrum light source 5 outputs a wide-spectrum light beam, the wide-spectrum light beam is transmitted to the grating simulation ring through the coupler 9 and the optical switch array 6, each section of Bragg grating in the grating simulation ring reflects light with specific wavelength at the current temperature, and the reflected light is transmitted to the photoelectric detector 8 through the coupler 9 and the tunable narrow-band filter.

The wide-spectrum light source 5 is connected with the structure body 1 through screws and is electrically welded with the light source driving board 11. The optical switch array 6 is connected with the structural body 1 by screws. The tunable narrow-band filter 7 is connected with the structural body 1 in a bonding mode through silicon rubber, and the coupler 9 is connected with the structural body 1 in a bonding mode through the silicon rubber. The photoelectric detector 8 is electrically welded with the signal processing module 10, and the optical switch array 6 is electrically welded with the signal processing module 10. The signal processing module 10 is connected with the structural body 1 by screws. The wide-spectrum light source 5, the coupler 9, the optical switch array 6, the grating simulation ring, the tunable narrow-band filter 7 and the photoelectric detector 8 are connected through the fusion of connecting tail fibers.

The circuit structure includes: a signal processing module 10 (information processing board) and a light source driving board 11. The information processing board comprises an FPGA logical operation unit, an A/D converter and an optical switch driving device, and the part is the content of the prior art. The light source driving board 11 drives the wide spectrum light source 5 to operate. The power and layout of heating power components in the information processing board and the light source driving board 5 are consistent with those of the information processing board and the light source driving board of the fiber-optic gyroscope, so that the effect of analog simulation is achieved. The A/D converter converts the acquired voltage analog signal output by the photoelectric detector into a digital signal, sends the digital signal to the FPGA logical operation unit for processing operation, demodulates the digital signal through a demodulation algorithm to obtain the real-time temperature of each section of Bragg grating in the grating analog loop, and simulates the temperature field model of the optical fiber loop in various working environments of the optical fiber gyroscope. The demodulation principle and the demodulation algorithm are the common techniques in the field.

In a further preferred technical scheme of the optical fiber ring simulation temperature measurement structure, a first groove and a second groove which are respectively used for accommodating the optical switch array 6 and the photoelectric detector 8 are formed in the other side of the structure body 1 in the length direction of the optical fiber ring structure 4.

As further illustrated below in conjunction with fig. 1-6, where K = 8.

The invention provides an optical fiber ring simulation temperature measurement structure based on an optical fiber grating, which designs an annular structure similar to the optical fiber ring, adopts a cylindrical winding method to wind a section of optical fiber containing the optical fiber grating into a regular octagonal annular column structure, utilizes a Bragg optical fiber grating temperature measurement technology to simulate and measure the real-time temperature of the optical fiber ring in various working environments, and establishes a temperature field model.

The shapes and areas of the patterns formed by the optical fibers in all layers are the same, namely the shapes and areas of the cross sections of the optical fiber ring structures 4 are the same. The cross section of the optical fiber ring structure 4 is an octagonal ring structure (hollow). The other end of each optical fiber is vacant.

On a section of optical fiber with the length equivalent to that of the optical fiber ring to be measured, a small section of Bragg grating is photoetched at each specific interval, each section of Bragg grating forms 1 path of Bragg grating, and each section of Bragg grating can reflect the optical wave signal with specific wavelength. The fiber rings wound with multiple bragg gratings are hereinafter referred to as grating simulation rings.

The light source driving board drives the wide-spectrum light source to output a wide-spectrum light beam, the wide-spectrum light beam is transmitted to the grating simulation ring through the coupler, each section of Bragg grating in the grating simulation ring reflects light with a specific wavelength at the current temperature, the reflected light is transmitted to the photoelectric detector through the coupler and the tunable narrow-band filter, the A/D converter in the data acquisition board converts the acquired voltage analog signal output by the photoelectric detector into a digital signal, the digital signal is sent to the FPGA logic operation unit for processing operation, the real-time temperature of each section of Bragg grating in the grating simulation ring is obtained through demodulation through a demodulation algorithm, and temperature field models of the optical fiber ring in various working environments of the optical fiber gyroscope are simulated.

A section of optical fiber with a plurality of Bragg gratings is adopted to wind a regular octagonal grating simulation ring 4, and the grating simulation ring is connected with the structure body 1 by epoxy AB glue.

The Bragg grating is influenced by the temperature change, the grating pitch of the grating changes, the wavelength of the light wave of the reflected wave changes accordingly, and the wavelength variation of the Bragg grating and the temperature variation have a corresponding relation, so that the temperature change is measured. The bragg grating thermometry is the content of the prior art.

In a preferred embodiment of the invention, the measurement range of each Bragg grating is-40 ℃ to +80 ℃, the measurement precision is 0.1 ℃, and the central wavelength of each Bragg grating is 1510-1590 nm. And photoetching 20 Bragg gratings in each optical fiber to form 1 optical fiber grating. These parameters are determined based on the actual operating temperature range of most fiber optic gyroscopes under operating conditions, as will be appreciated by those skilled in the art.

In a preferred embodiment of the present invention, the optical switch array 6 selects 4 optical switches to control the on/off of 4 fiber gratings, and there are 4 × 20 (80) bragg grating temperature measurement points in the grating simulation ring.

In a preferred embodiment of the present invention, the grating simulation ring 4 has 20 layers, each layer has 40 turns, and each layer of optical fiber is distributed with 4 bragg grating temperature measurement points, which are respectively in the 5 th turn, 15 th turn, 25 th turn and 35 th turn of each layer of optical fiber.

In a preferred embodiment of the present invention, in the signal processing module 10, the fiber grating wavelength demodulation range 1510-1590nm, the wavelength resolution 1pm, the wavelength demodulation precision 3pm, and the demodulation scanning frequency 50 Hz.

The 20 measurement nodes in each path are different wave bands in 1510-.

After the broadband light is emitted by the wide-spectrum light source 5, the reflection wavelength of each Bragg grating is different, and the wavelength and the change of the reflected light can be obtained after the reflected light is demodulated, so that the measurement temperature of each Bragg grating can be obtained.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.

The embodiments of the present invention have been described in detail, but the description is only for the preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made within the scope of the present invention should be covered by the present patent. After reading this disclosure, modifications of various equivalent forms of the present invention by those skilled in the art will fall within the scope of the present application, as defined in the appended claims. The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.