CN101539427B

CN101539427B - Optical fiber gyroscope coil with parallelogram cross section

Info

Publication number: CN101539427B
Application number: CN2009100959559A
Authority: CN
Inventors: 刘瑞; 刘承; 舒晓武; 张彩妮
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2009-02-26
Filing date: 2009-02-26
Publication date: 2010-11-03
Anticipated expiration: 2029-02-26
Also published as: CN101539427A

Abstract

The invention discloses an optical fiber gyroscope coil with a parallelogram cross section. The optical fiber gyroscope coil consists of a plurality of equal-vertex angle coaxial line conical surface-shaped optical fiber layers formed by winding according to the four-pole winding method; the vertex angle of the conical surface located by each optical fiber layer is 60 degrees; the planes located by the top circle and the bottom circle of optical fibers of each optical fiber layer are vertical to an axial line of the conical surface; and the centers of the adjacent optical fiber cross sections in the coil cross section are arranged like an equilateral triangle. The centers of the adjacent optical fiber cross sections in the coil cross section are arranged like the equilateral triangle, thereby significantly reducing the stress generated by extrusion; the coil cross section is a parallelogram with acute angles of 60 degrees, thereby reducing the significant stress difference between the symmetric sections of the optical fibers which are near to a framework in the coil; and the shape of the coil can effectively improve the temperature performance of the optical fiber gyroscope coil.

Description

The optical fiber gyro coil of parallelogram section

Technical field

The present invention relates to optical fiber gyro coil, especially relate to a kind of optical fiber gyro coil of parallelogram section.

Background technology

Interferometric fiber optic gyroscope is a kind of rotation angle rate sensor based on Sagnac (Sagnac) effect, its minimum reciprocal structure comprises following a few part: a light source, a detector, an optical fiber directional coupler, a polarizer (comprising one or more depolarizers sometimes), an integrated optics Y waveguide, a fiber optic sensing coil that turns to by polarization maintaining optical fibre or standard telecommunications single-mode fiber.The light that light source sends is divided into along the light of the positive and negative two directions transmission of coil by Y waveguide through coupling mechanism, forms interference by the Y waveguide coupling and through coupling mechanism at the receiving end of detector through two-beam behind the coil.During the coil rotation, the light path difference of two-beam experience, the interference light intensity that detector receives changes thereupon, detects the rotation angle speed with the coil stationary platform thus.

Series of advantages such as that optical fibre gyro has is highly reliable, long-life, startup fast, great dynamic range.The structure of whole solid state of optical fibre gyro makes it have prior advantage than the mechanical rotor that adopted in the past or the scheme of gas ring laser.But environmental factor still can influence the output of optical fibre gyro by the phase differential that changes positive and negative two-beam in the fiber optic coils.When these environmental factors change and in whole section optical fiber during asymmetric distribution in time, light along the positive and negative two directions transmission of optical fiber will experience different phase places, produce the phase shift with the coil irrelevant to rotation, thereby the Sagnac phase shift that this phase shift and rotation cause can't be distinguished and causes systematic error.During variation of ambient temperature, become when in optical fiber, existing the asymmetric temperature field, hot expansibility between optical fiber gyro coil and the skeleton does not match and has extra heat stress in the optical fiber with causing, and this extra heat stress becomes asymmetric when same, thereby causes the temperature sensitivity of optical fibre gyro.The temperature sensitivity of optical fibre gyro has become the principal element of its widespread use of restriction.

The method of the reduction optical fibre gyro temperature sensitivity of existing widespread usage variously makes in the optical fiber temperature field and the extra heat stress symmetry as far as possible that distributes for the symmetrical windings that strengthen reciprocity for using on the basis of square-section fiber optic coils.For example use the optical fiber gyro coil of quadrapole winding coiling to demonstrate, but still can not eliminate the error that variation of ambient temperature causes fully than the better temperature characterisitic of original scroll winding.

Being illustrated in figure 1 as existing cross section is rectangle, and the optical fiber gyro coil cross section partial enlarged drawing that adjacent fiber kernel of section quadrate is arranged on the cross section.A continuous optical fiber 11 uses the quadrapole winding to turn to coil 10, and the adjacent fiber kernel of section quadrate of optical fiber 11 is arranged, and coil 10 adjacent external surfaces (for example coil lower surface 12 and coil inside surface 13) are orthogonal.The adjacent fiber square arrangement makes in the coil 10 near the symmetric sections optical fiber at skeleton 14 places (for example the 3rd layer is played circle optical fiber 15, the 4th layer to play circle optical fiber 16 most most) identical with the gap between the skeleton 14, thereby has avoided changing the weakening that layer is located the quadrapole winding advantage that the remarkable stress difference of symmetric sections optical fiber brings.But when variation of ambient temperature, owing to matching, hot expansibility in coil 10, do not produce extra heat stress between coil 10 that optical fiber 11 turns to and the skeleton 14 with causing.Under the driving of this thermal stress, the displacement trend direction of optical fiber be coil axes to 17 with coil radially 18, what contact with optical fiber is adjacent fiber or skeleton in that this side up, thus cause between the optical fiber or optical fiber and skeleton between mutual extrusion produce remarkable stress.The small quadrapole non-ideal factor that actual winding process is introduced inevitably produces remarkable nonreciprocal effect with remarkable therewith stressed bond, and then causes the temperature of optical fibre gyro to rely on output error.

Fig. 2 is a rectangle for existing cross section, and the adjacent fiber kernel of section becomes the optical fiber gyro coil cross section partial enlarged drawing of triangular arranged on the cross section.Different with Fig. 1 is that the adjacent fiber kernel of section of optical fiber 21 becomes triangular arranged in the coil 20.When this optical fiber arrangements mode makes variation of ambient temperature, optical fiber is in one of displacement trend direction that produces under the driving of extra heat stress---and radially there is optical fiber gap 22 in coil on 28, thereby has reduced between the optical fiber or mutual extrusion produces between optical fiber and the skeleton remarkable stress.But in the coil 20 near the symmetric sections optical fiber at skeleton 24 places (for example the 1st layer is played circle optical fiber 25, the 2nd layer to play circle optical fiber 26 most most) because different with the gap between the skeleton 24, to have remarkable stress difference, this species diversity will obviously weaken the excellent properties that the quadrapole winding is brought.

In a word, for reducing the influence of environment temperature to optical fibre gyro, existing a large amount of improvement winding method to fiber optic coils exists, but these methods all are based upon on the basis of coil shape that the cross section is a rectangle, be subjected to having a strong impact on of the non-ideal factor that produces in the actual winding process inevitably, can not give full play to quadrapole and other improve the advantage of windings.So, except that winding method, carefully design the coil shape of optical fibre gyro and wherein the optical fiber arrangement mode be to improve the effective means of optical fibre gyro temperature performance.

Summary of the invention

Can not give full play to the problem of quadrapole and other improvement winding advantages at optical fiber gyro coil shape in the background technology, the object of the present invention is to provide a kind of optical fiber gyro coil of parallelogram section, become the nonreciprocal problem that asymmetric thermal stress causes when solving in the background technology in the coil, improve the temperature performance of optical fibre gyro.

The technical solution used in the present invention is as follows:

Optical fiber gyro coil of the present invention is made up of a plurality of optical fiber layers of drift angle coaxial cable conical surface-shaped that wait that the coiling of quadrapole winding forms; Every layer of optical fiber place circular conical surface drift angle is 60 degree; Every layer of optical fiber is gone up circle most and is played plane, circle optical fiber place and described circular conical surface axis normal most; The adjacent fiber kernel of section becomes triangular arranged in the coil section.

The beneficial effect that the present invention has is:

(1) the adjacent fiber kernel of section becomes triangular arranged in the coil section, makes extruding produce stress and significantly reduces.

(2) to acutangulate be the parallelogram of 60 degree to coil section, reduced in the coil the remarkable stress difference near the symmetric sections optical fiber at skeleton place.

(3) coil shape can effectively improve the temperature performance of optical fiber gyro coil.

Description of drawings

Fig. 1 is that existing cross section is a rectangle, the optical fiber gyro coil cross section partial enlarged drawing that adjacent fiber kernel of section quadrate is arranged on the cross section.

Fig. 2 is that existing cross section is a rectangle, and the adjacent fiber kernel of section becomes the optical fiber gyro coil cross section partial enlarged drawing of triangular arranged on the cross section.

Fig. 3 is that the cross section that the present invention proposes is a parallelogram, and the adjacent fiber kernel of section becomes the optical fiber gyro coil sectional view of triangular arranged on the cross section.

Fig. 4 is the partial enlarged drawing of Fig. 3 near the skeleton part.

Among the figure: 10, coil, 11, optical fiber, 12, the coil lower surface, 13, the coil inside surface, 14, skeleton, 15, the 3rd layer is played circle optical fiber most, 16, the 4th layer is played circle optical fiber, 17 most, coil axes to, 18, coil radially, 20, coil, 21, optical fiber, 22, the optical fiber gap, 24, skeleton, 25, the 1st layer is played circle optical fiber, 26 most, the 2nd layer is played circle optical fiber most, 28, coil radially, 30, coil, 31, optical fiber, 32, skeleton, 33, the inner edge of coil section, 34, coil section outermost sideline, 35, coil section is line topmost, 36, coil section is line bottom, 37, the optical fiber section, 38, the optical fiber gap, 39, optical fiber layer circular conical surface axis of living in, 40, coil lower surface vertical line direction, 41, coil inside surface vertical line direction, 42, the 3rd layer is played circle optical fiber, 43 most, the 4th layer is played circle optical fiber most.

Embodiment

The invention will be further described below in conjunction with drawings and Examples.

As shown in Figure 3, be that the cross section that the present invention proposes is a parallelogram, the adjacent fiber kernel of section becomes the optical fiber gyro coil sectional view of triangular arranged on the cross section, and Fig. 4 is the partial enlarged drawing of Fig. 3 near the skeleton part.Coil 30 uses the coiling of quadrapole winding to form by a continuous optical fiber 31, and the adjacent fiber kernel of section becomes triangular arranged on coil 30 cross sections.Coil 30 is made up of a plurality of optical fiber layers of drift angle coaxial cable conical surface-shaped that wait, and the cross section becomes parallelogram, and inner edge 33 of coil section and coil section outermost sideline 34 and optical fiber layer circular conical surface axis 39 angles of living in are 30 to spend; Coil section topmost line 35 and coil section line 36 and optical fiber layer circular conical surface axis of living in 39 is vertical bottom.The remarkable stress similar to coil principle shown in Figure 2, that mutual extrusion produced between the optical fiber or between optical fiber and the skeleton when optical fiber of triangular arranged had reduced variation of ambient temperature.With optical fiber section 37 is example, the displacement trend direction that produces under the driving of extra heat stress during variation of ambient temperature is coil lower surface vertical line direction 40 and coil inside surface vertical line direction 41, the optical fiber that this side up and be studied sections 37 adjacent be optical fiber gap 38 all, thereby effectively reduced in the optical fiber because the remarkable stress that extruding produces.Simultaneously, the illustrated coil shape makes this coil identical with the gap between the skeleton 32 near the symmetric sections optical fiber at skeleton 32 places (for example the 3rd layer is played circle optical fiber 42, the 4th layer to play circle optical fiber 43 most most), with the remarkable stress difference that does not exist in Fig. 2 coil, improve the excellent properties that winding is brought thereby kept quadrapole winding or other.And cooperate with respect to traditional cylindrical surface, the conical surface of skeleton 32 cooperates with the conical surface of coil 30 and will guarantee that the main shaft of coil 30 overlaps with the main shaft of skeleton 32 easilier.

This shows that the present invention is arranged as equilateral triangle with adjacent fiber kernel of section in the coil section, the extra-stress that mutual extrusion produces when significantly having reduced variation of ambient temperature; Coil section is designed to the parallelogram of acute angle 60 degree, has effectively reduced the stress difference that different gap produces between the symmetric sections optical fiber that is in coil surface and the skeleton, coil shape can effectively improve the temperature performance of optical fiber gyro coil.

Claims

1. the optical fiber gyro coil of a parallelogram section is characterized in that: optical fiber gyro coil is made up of a plurality of optical fiber layers of drift angle coaxial cable conical surface-shaped that wait that the coiling of quadrapole winding forms; The cross section becomes parallelogram, and inner edge of coil section and coil section outermost sideline and optical fiber layer circular conical surface axis angle of living in are 30 to spend; Coil section the top line and coil section be line and optical fiber layer circular conical surface axis normal of living in bottom; The adjacent fiber kernel of section becomes triangular arranged in the coil section.