A high-precision fiber-optic gyroscope performance guarantee method

Abstract

The application discloses a high-precision fiber-optic gyroscope performance guarantee method, which comprises the following steps: controlling so that the light power entering a detector is not more than the saturation light power of the detector; and controlling so that the power loss of any fiber fusion joint is not more than a preset power loss value. The light path matching and light path parameter control method provided by the application has high operability, can meet the requirements of high-precision fiber-optic gyroscope light path assembly, can effectively guarantee the signal strength and light path quality of the high-precision fiber-optic gyroscope, and thus guarantees the working performance of the high-precision fiber-optic gyroscope.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber sensing technology, and more particularly, to a high-precision fiber-optic gyroscope performance guarantee method. BACKGROUND

[0002] The high-precision fiber-optic gyroscope is a high-precision inertial instrument, which functions to sense the angular rate change of a carrier based on the Sagnac effect. The Sagnac effect refers to that, in a closed optical loop, two beams of light transmitted in opposite directions along clockwise (CW) and counterclockwise (CCW) directions produce a phase difference change due to the rotation of the optical loop around an axis perpendicular to the loop plane, and the phase difference is proportional to the rotation rate of the closed optical loop.

[0003] With the continuous improvement of the precision of the gyroscope, the device selection and assembly requirements of the optical system are becoming higher and higher. However, since the current high-precision fiber-optic gyroscope optical device matching method is not fine enough, the optical path fusion quality is controlled by comparing the light power before the probe and the ASE light output power, and this kind of control method cannot monitor the optical path fusion quality throughout the process, and cannot better guarantee the working performance of the high-precision fiber-optic gyroscope. SUMMARY

[0004] In view of at least one defect or improvement demand in the prior art mentioned in the background section, the present application provides a high-precision fiber-optic gyroscope performance guarantee method to overcome the technical defects that the current high-precision fiber-optic gyroscope optical device matching method is not fine enough, the optical path fusion quality is controlled by comparing the light power before the probe and the ASE light output power, and the existing control method cannot monitor the optical path fusion quality throughout the process, and cannot better guarantee the working performance of the high-precision fiber-optic gyroscope.

[0005] To achieve the above-mentioned purpose, the present application provides a high-precision fiber-optic gyroscope performance guarantee method, wherein the optical path part of the high-precision fiber-optic gyroscope is composed of an ASE light source assembly, a coupler, a Y waveguide, a fiber ring and a probe.

[0006] The ASE light source assembly, the coupler, the Y waveguide and the fiber ring are connected in sequence by optical fibers.

[0007] The first end of the fiber ring is connected to the first end of the Y waveguide by an optical fiber, and the second end of the fiber ring is connected to the second end of the Y waveguide by an optical fiber.

[0008] The coupler and the probe are connected by an optical fiber.

[0009] The performance guarantee method comprises:

[0010] controlling so that the light power entering the probe does not exceed the saturation light power of the probe;

[0011] controlling so that the power loss of any fiber fusion point does not exceed a preset power loss value.

[0012] Further, the formula of the optical power entering the probe includes:

[0013]

[0014] wherein P D represents the optical power entering the probe, P ASE represents the output optical power of the ASE light source assembly, L 总 represents the total power loss of the optical path part.

[0015] Further, the formula of the total power loss of the optical path part includes:

[0016] L 总 = 2 * L split + 2 * L add + L pol + 2 * L insert + L coil + L point总

[0017] wherein the splitting loss of the coupler is L split , the additional loss is L add ; the polarization loss of the Y waveguide is L pol , the insertion loss is L insert ; the loss of the fiber ring is L coil ; L point总 is the total power loss of all fiber fusion points.

[0018] Further, the formula of the saturation optical power of the probe includes:

[0019] P = (V - V d ) / S (m)

[0020] wherein P represents the saturation optical power of the probe, V represents the direct current saturation voltage, V d represents the no-light output voltage, and S (m) represents the voltage responsivity.

[0021] Further, controlling so that the power loss of the fiber fusion point between the ASE light source assembly output fiber and the coupler does not exceed a preset power loss value;

[0022] The formula of the power loss of the fiber fusion point between the ASE light source assembly output fiber and the coupler includes:

[0023]

[0024] wherein LASE represents the power loss of the fiber splice between the output fiber of the ASE light source assembly and the coupler; P ASE represents the output power of the ASE light source assembly, which can be measured; P1 represents the optical power measured at the first fiber splice between the coupler and the Y waveguide.

[0025] Further, the power loss of the first fiber splice is controlled to not exceed a preset power loss value.

[0026] The formula of the power loss of the first fiber splice includes:

[0027]

[0028] wherein L1 represents the power loss of the first fiber splice, P2 represents the optical power measured at the second fiber splice between the first end of the Y waveguide and the first end of the fiber loop, and P3 represents the optical power measured at the third fiber splice between the second end of the Y waveguide and the second end of the fiber loop.

[0029] Further, the power loss of the second fiber splice is controlled to not exceed a preset power loss value.

[0030] The formula of the power loss of the second fiber splice includes:

[0031]

[0032] wherein L2 represents the power loss of the second fiber splice.

[0033] Further, the power loss of the third fiber splice is controlled to not exceed a preset power loss value.

[0034] The formula of the power loss of the third fiber splice includes:

[0035]

[0036] wherein L3 represents the power loss of the third fiber splice, and P4 represents the optical power measured at the fourth fiber splice between the coupler and the detector.

[0037] Further, the power loss of the fourth fiber splice is controlled to not exceed a preset power loss value.

[0038] The formula of the power loss of the fourth fiber splice includes:

[0039]

[0040] wherein L4 represents the power loss of the fourth fiber splice, and V represents the voltage of the detector.PP represents a voltage value at which the detector currently operates, and R represents an impedance of the detector.

[0041] Further, the preset power loss value is 0.3dB.

[0042] Overall, compared with the prior art, the above technical solutions conceived by the present application can achieve the following beneficial effects:

[0043] The optical path matching and optical path parameter control method provided by the present application has high operability, can meet the requirements of high-precision fiber-optic gyroscope optical path assembly, can effectively guarantee the signal strength and optical path quality of the high-precision fiber-optic gyroscope, and thus guarantees the working performance of the high-precision fiber-optic gyroscope. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0045] Figure 1 A flowchart of a high-precision fiber-optic gyroscope performance guarantee method provided by the present application is shown in the figure.

[0046] Figure 2 A structure diagram of an optical path parameter control system of a high-precision fiber-optic gyroscope provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0048] The terms "first", "second" or "third" and the like in the specification of the present application, claims or the above drawings are used to distinguish different objects, and are not used to describe a specific order. In addition, the terms "include" or "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product or device.

[0049] AsFigure 1 As shown in one embodiment, a high-precision fiber-optic gyroscope performance guarantee method is provided. The light path part of the high-precision fiber-optic gyroscope is composed of an ASE light source assembly, a coupler, a Y waveguide, a fiber ring, and a detector. Figure 2 The ASE light source assembly, the coupler, the Y waveguide, and the fiber ring are sequentially connected by optical fibers, that is, the ASE light source assembly, the coupler, the Y waveguide, and the fiber ring all have tail fibers, and the tail fibers are sequentially connected by fusion splicing. The first end of the fiber ring is connected to the output first end of the Y waveguide through an optical fiber, and the second end of the fiber ring is connected to the output second end of the Y waveguide through an optical fiber. The output end of the coupler and the input end of the detector are connected by an optical fiber.

[0050] The performance guarantee method mainly includes the following two steps (step 1 and step 2).

[0051] Step 1, control so that the optical power entering the detector does not exceed the saturation optical power of the detector. This step includes the selection of optical devices and the calculation of optical path loss to screen optical devices that meet the requirements.

[0052] When designing the optical path, the output optical power P ASE of the ASE light source assembly, the beam splitting loss L split of the coupler, the additional loss L add , the polarization loss L pol and the insertion loss L insert of the Y waveguide, and the fiber ring loss L coil are taken as the selection factors of the optical devices.

[0053] The ASE light source assembly has red and black lines, which are connected to +5V and GND of the direct current power supply, respectively, as shown in Figure 2 .

[0054] The selection of optical devices takes the saturation optical power of the detector as one of the selection factors, controls the saturation optical power through the direct current saturation voltage, the lightless negative bias voltage, and the voltage responsivity of the optical device itself, and the specific relationship is as follows:

[0055] P=(V﹣V d ) / S(m)(1)

[0056] Where P is the saturation optical power of the detector.

[0057] V is the direct current saturation voltage, which is a constant value, generally set to 3.45V by the manufacturer.

[0058] V d is the lightless output voltage, that is, the lightless negative bias voltage.

[0059] S(m) is the voltage responsivity.

[0060] The output power P of the ASE light source assembly ASE is the light power measured by the tail fiber port of the light source. The coupler splitting loss L split and the additional loss L add , the Y waveguide polarization loss L pol and the insertion loss L insert , the fiber ring loss L coil are all the device performance parameters recorded on the device itself.

[0061] The calculation factors of the optical path loss include the coupler splitting loss L split and the additional loss L add , the Y waveguide polarization loss L pol and the insertion loss L insert , the fiber ring loss L coil and the total fusion point loss. The calculation formula of the total optical path power loss is as follows:

[0062] L 总 = 2*L split + 2*L add + L pol + 2*L insert + L coil + L point总 (2)

[0063] L 总 represents the total optical path power loss, and L point总 represents the total power loss of all fiber fusion points.

[0064] The formula of the light power entering the detector is:

[0065]

[0066] P D represents the light power entering the detector, which is controlled to be not greater than the saturation light power P of the detector, that is, to ensure

[0067] Step 2, control so that the power loss of any fiber fusion point does not exceed the preset power loss value. The key of this step is to control the fusion point power loss (referred to as: fusion point loss). The fusion point loss refers to the light power loss caused by the newly added fusion point after the tail fibers of different devices are fused. The quality of the optical path fusion can be monitored by an optical power meter. Each device has its own fiber, called a tail fiber, and the tail fibers of each device are connected by fusion. P1 to P4 are several fiber fusion test points, as shown in Figure 2 , which can be measured by an optical power meter to obtain the light power value of the corresponding point, and then the corresponding test points are fused to construct the entire fiber structure.

[0068] First, the P ASE Then, according to formula (4)

[0069]

[0070] The power loss of the fiber fusion point P ASE between the tail fiber of the ASE light source assembly and the coupler is calculated. P1 represents the optical power measured at the first fiber fusion point P1 between the coupler and the Y waveguide, i.e. P1 is the optical power entering the input end of the Y waveguide, which can be measured by an optical power meter.

[0071] Then, according to formula (5)

[0072]

[0073] The power loss L1 of the first fiber fusion point P1 is calculated. P2 represents the optical power measured at the second fiber fusion point P2 between the first output end of the Y waveguide and the first end of the fiber ring, i.e. P2 represents the optical power entering the first end of the fiber ring; P3 represents the optical power measured at the third fiber fusion point P3 between the second output end of the Y waveguide and the second end of the fiber ring, i.e. P3 represents the optical power entering the second output end of the Y waveguide.

[0074] Then, according to formula (6)

[0075]

[0076] The power loss L2 of the second fiber fusion point P2 is calculated.

[0077] Then, according to formula (7)

[0078]

[0079] The power loss L3 of the third fiber fusion point P3 is calculated, and P4 represents the optical power measured at the fourth fiber fusion point P4 between the coupler and the detector, i.e. P4 represents the optical power entering the input end of the detector.

[0080] Then, according to formula (8)

[0081]

[0082] The power loss L4 of the fourth fiber fusion point P4 is calculated, and V PP represents the current working voltage of the detector, and R represents the impedance of the detector.

[0083] V PP The measurement method of the V 2πwave signal, and then output the square wave signal, the frequency of which is set as the eigenfrequency of the fiber ring, according to the value of the low level of the square wave displayed on the oscilloscope minus V d , that is, the value of V PP . V 2π is the 2π voltage value of the Y waveguide.

[0084] Various parameters are controlled so that the power loss values of all the above fiber fusion points (including P ASE point, P1 point, P2 point, P3 point and P4 point) do not exceed 0.3 dB.

[0085] The method of the present application can be operated with high operability, can meet the requirements of high-precision fiber-optic gyroscope optical path assembly, can effectively guarantee the signal strength and optical path quality of high-precision fiber-optic gyroscope, and thus guarantees the working performance of high-precision fiber-optic gyroscope.

[0086] The above-described are only exemplary embodiments of the present disclosure, and cannot limit the scope of the present disclosure. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. Other embodiments of the present disclosure will be readily apparent to those skilled in the art upon considering the specification and practicing the present disclosure herein. The present disclosure is intended to cover any variations, uses, or adaptive changes of the present disclosure that follow the general principles of the present disclosure and include common knowledge or conventional technical means in the technical field not recorded in the present disclosure. The specification and examples are only considered as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0087] The technical features of the above embodiments can be combined in any manner. In order to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictions, they should be considered as the scope of the present disclosure.

[0088] Those skilled in the art readily understand that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-precision fiber-optic gyroscope performance guarantee method, characterized in that, The light path part of the high-precision fiber-optic gyroscope is composed of an ASE light source assembly, a coupler, a Y waveguide, a fiber ring and a detector; The ASE light source assembly, the coupler, the Y waveguide and the fiber ring are connected in sequence through optical fibers; The first end of the fiber ring is connected to the first end of the Y waveguide through an optical fiber, and the second end of the fiber ring is connected to the second end of the Y waveguide through an optical fiber; The coupler and the detector are connected through an optical fiber; The performance guarantee method comprises: controlling so that the optical power entering the detector does not exceed the saturation optical power of the detector, including the selection of optical devices and the calculation of optical path loss, to screen optical devices that meet the requirements, and taking the light output power of the ASE light source assembly, the beam splitting loss and additional loss of the coupler, the polarization loss and insertion loss of the Y waveguide, and the loss of the fiber ring as the selection factors of the optical devices during the design of the optical path; The formula of the optical power entering the probe includes: ; wherein, represents the optical power entering the probe, represents the output optical power of the ASE light source assembly, represents the total power loss of the optical path part; controlling so that the power loss of any optical fiber fusion point does not exceed a preset power loss value; The power loss of the optical fiber fusion point is the loss of optical power caused by the newly added fusion point after the tail fibers of different devices are fused to the axis; including the power loss of the optical fiber fusion point between the light output tail fiber of the ASE light source assembly and the coupler, the power loss of the first optical fiber fusion point, the power loss of the second optical fiber fusion point, the power loss of the third optical fiber fusion point and the power loss of the fourth optical fiber fusion point.

2. The performance assurance method of claim 1, wherein, The formula of the total power loss of the light path part comprises: ； The coupling loss of the coupler is , and the additional loss is ; the polarization loss of the Y waveguide is , and the insertion loss is ; the loss of the fiber ring is ; The power loss of all fiber splices is summed up.

3. The performance assurance method of claim 1, wherein, The formula of the saturation optical power of the detector comprises: ； wherein represents the saturation optical power of the probe, represents the direct current saturation voltage, represents the no light output voltage, represents the voltage responsivity.

4. The performance assurance method of claim 1, wherein, controlling so that the power loss of the optical fiber fusion point between the light output tail fiber of the ASE light source assembly and the coupler does not exceed a preset power loss value; The formula of the power loss of the optical fiber fusion point between the light output tail fiber of the ASE light source assembly and the coupler comprises: ； wherein, P1 represents the power loss of the fiber fusion joint between the light output tail fiber of the ASE light source assembly and the coupler; P2 represents the light output power of the ASE light source assembly, which can be measured; P3 represents the light power measured at the first fiber fusion joint between the coupler and the Y waveguide.

5. The performance assurance method of claim 1, wherein, controlling so that the power loss of the first optical fiber fusion point does not exceed a preset power loss value; The formula of the power loss of the first optical fiber fusion point comprises: ； wherein, P1 represents the power loss of the first fiber splice, P2 represents the optical power measured at the second fiber splice between the first end of the Y waveguide and the first end of the fiber loop, P3 represents the optical power measured at the third fiber splice between the second end of the Y waveguide and the second end of the fiber loop.

6. The performance assurance method of claim 1, wherein, controlling so that the power loss of the second optical fiber fusion point does not exceed a preset power loss value; The formula of the power loss of the second optical fiber fusion point comprises: ； wherein represents the power loss of the second fiber splice.

7. The performance assurance method of claim 1, wherein, controlling so that the power loss of the third optical fiber fusion point does not exceed a preset power loss value; The formula of the power loss of the third optical fiber fusion point comprises: ； wherein, represents the power loss of the third fiber splice, represents the optical power measured at the fourth fiber splice between the coupler and the probe.

8. The performance assurance method of claim 1, wherein, controlling so that the power loss of the fourth optical fiber fusion point does not exceed a preset power loss value; The formula of the power loss of the fourth optical fiber fusion point comprises: ； wherein, represents a power loss of the fourth optical fiber splice, represents a voltage value at which the probe is currently operating, represents an impedance of the probe.

9. The performance assurance method of any of claims 1-8, wherein, The preset power loss value is 0.3 dB.

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