CN202748004U - Fibre grating displacement sensor - Google Patents

Abstract

The utility model provides a fibre grating displacement sensor, which comprises at least two fibre gratings, at least two strain beams, an inclined surface, a probe and an analyzing module, wherein one ends of the fibre gratings are fixed; the other ends of the fibre gratings are respectively installed on different strain beams; one ends of the strain beams are fixed; each strain beam is provided with a contact part contacted with the inclined surface; combinations of position information of the contact parts on at least two strain beams on the inclined surface are different at different times; when displacement exists outside, the contact parts relatively move on the inclined surface; the strain beams having strain result in that the fibre gratings generate strain; the probe is connected with the inclined surface; and the analyzing module is used for obtaining the outside displacement according to the strain combination of the fibre gratings. The fibre grating displacement sensor disclosed by the utility model has the advantages of being high in measurement range, high in flexibility and the like.

Description

Fiber grating displacement sensor

Technical field

The utility model relates to the measurement of displacement, particularly fiber grating displacement sensor.

Background technology

Optical fiber is when small stretching, and the wavelength of Fiber Bragg Grating FBG (hereinafter to be referred as grating) and the small displacement of stretching are linear.The fibre-optical raster crack meter namely is by certain device, and linear this micro-displacement that amplifies is realized the measurement to the larger displacement in outside.

Fig. 1 has schematically provided the schematic diagram of slit gauge in the prior art, as shown in Figure 1, when the external world has displacement, when the pull bar pull of slit gauge moves, be connected the upper top that the inclined-plane then can cause feeler lever with pull bar, the top can cause again the variation of grating strain beam deflection on the feeler lever, and the variation of this amount of deflection then can be passed to grating, makes grating that the wavelength variations of measuring occur.But amount of deflection little in the grating strain beam elastic range changes approximately linear, and the slit gauge of this structure namely by the linear transformation of inclined-plane-amount of deflection, is realized the measurement of the large displacement of pull bar.Range is the horizontal length on inclined-plane, and sensitivity is feeler lever poor ratio with range of grating wavelength when being in inclined-plane bottom, top.

Since the material of optical fiber own, in elastic range, the amount of tension of grating very little (being that wavelength variable quantity is very little).In the practical application, be not damaged in order to protect grating, the wavelength variations general control of grating is about 4nm in the slit gauge.At present, the slit gauge in the optical fiber industry all adopts the monochromatic light grid to carry out displacement measurement, has many deficiencies, as:

1, range one timing of slit gauge, sensitivity is the 4nm/ range to the maximum, can't improve again;

When 2, keeping the sensitivity of maximum, can't improve range;

3, in each range interval, sensitivity is constant, does not have multistage sensitivity.

The utility model content

In order to solve the deficiency in the above-mentioned prior art scheme, the utility model provides a kind of range large, highly sensitive fiber grating displacement sensor.

The purpose of this utility model is achieved through the following technical solutions:

Fiber grating displacement sensor, described displacement transducer comprises:

At least two fiber gratings, an end of described fiber grating is fixed, and the other end is installed in respectively on the different strain beams;

At least two strain beams, an end of described strain beam is fixed, and has the contact element that contacts with the inclined-plane on the strain beam;

The inclined-plane; In difference constantly, the combination of the positional information of contact element on the inclined-plane at least two strain beams has difference; When the external world had displacement, described contact element had on described inclined-plane and relatively moves, and the described strain beam of strain occured so that described fiber grating produces strain;

Probe, described probe is connected with described inclined-plane;

Analysis module, described analysis module obtains extraneous displacement according to the combination of the strain of described fiber grating.

According to above-mentioned displacement transducer, alternatively, described inclined-plane is one, and the contact element of described at least two strain beams divides the time to be located on described inclined-plane, perhaps is in respectively on the differing heights on described inclined-plane.

According to above-mentioned displacement transducer, alternatively, described inclined-plane is two or more, and the contact element of described at least two strain beams can relatively move on one or more inclined-planes respectively.

According to above-mentioned displacement transducer, alternatively, at synchronization, only there is a contact element to be on the inclined-plane, perhaps different contact elements is in respectively on the different inclined-planes.

According to above-mentioned displacement transducer, alternatively, described inclined-plane is plane or curved surface.

According to above-mentioned displacement transducer, alternatively, described analysis module is used for knowing the residing range of extraneous displacement, sensitivity interval according to the combination of the strain of described fiber grating.

According to above-mentioned method for sensing, alternatively, described inclined-plane is plane or curved surface.

Compared with prior art, the beneficial effect that the utlity model has is:

1, in the certain situation of range, (exponentially) improved the sensitivity of displacement transducer, and different version can improve different multiples;

2, in range ability, can be with the sensitivity segmentation, the sensitivity that different range sections is corresponding different;

3, in the certain situation of sensitivity, improve the range of displacement transducer.

Description of drawings

With reference to accompanying drawing, disclosure of the present utility model will be easier to understand.Those skilled in the art are understood that easily: these accompanying drawings only are used for illustrating the technical solution of the utility model, and are not to be intended to protection domain of the present utility model is construed as limiting.Among the figure:

Fig. 1 is the basic block diagram according to slit gauge in the prior art;

Fig. 2 is the basic block diagram according to the utility model embodiment 1,2 displacement transducer;

Fig. 3 is the process flow diagram according to the displacement sensing method of the utility model embodiment 1;

Fig. 4 is the basic block diagram according to the displacement transducer of the utility model embodiment 3;

Fig. 5 is the basic block diagram according to the displacement transducer of the utility model embodiment 4;

Fig. 6 is the basic block diagram according to the displacement transducer of the utility model embodiment 4;

Fig. 7 is the basic block diagram according to the displacement transducer of the utility model embodiment 5;

Fig. 8 is the basic block diagram according to the displacement transducer of the utility model embodiment 6;

Fig. 9 is the basic block diagram according to the displacement transducer of the utility model embodiment 7;

Figure 10 is the basic block diagram according to the displacement transducer of the utility model embodiment 8.

Embodiment

Fig. 2-10 and following declarative description optional embodiment of the present utility model how to implement with instruction those skilled in the art and reproduce the utility model.In order to instruct technical solutions of the utility model, simplified or omitted some conventional aspects.Those skilled in the art should understand that the modification that is derived from these embodiments or replace will be in scope of the present utility model.Those skilled in the art should understand that following characteristics can make up to form a plurality of modification of the present utility model in every way.Thus, the utility model is not limited to following optional embodiment, and is only limited by claim and their equivalent.

Embodiment 1:

Fig. 2 has schematically provided the basic block diagram of the fiber grating displacement sensor of the utility model embodiment.As shown in Figure 2, described sensor comprises:

At least two fiber gratings, such as Bragg grating, an end of described fiber grating is fixed, and the other end is installed in respectively on the different strain beams;

At least two strain beams, an end of described strain beam is fixed, and has the contact element that contacts with the inclined-plane on the strain beam; The initial position of at least one contact element is in the bottom on inclined-plane; Described strain beam is the state of the art, does not repeat them here.

The inclined-plane; In difference constantly, the combination of the positional information of contact element on the inclined-plane at least two strain beams has difference, it is different from the relative position on inclined-plane also to be that described contact element is in, as: the differing heights place on same inclined-plane, or a part of contact element is in, and another part is on the plane on the inclined-plane, or the equal height place on different inclined-planes, or the differing heights place on different inclined-planes; When the external world had displacement, described contact element had on described inclined-plane and relatively moves, and the described strain beam of strain occured so that described fiber grating produces strain;

Probe, described probe is connected with described inclined-plane;

Analysis module, described analysis module obtains extraneous displacement according to the combination of the strain of described fiber grating, the sensitivity that this displacement is corresponding certain.

Certainly, described sensor also comprises light source, shunt and spectrometer, and the light that light source sends enters optical fiber by a road of shunt, through fiber grating the time, part light is reflected by former road, is received by spectrometer through behind the shunt, can obtain the wavelength variations of fiber grating.These devices and concrete connected mode are to hold intelligible prior art for those skilled in the art, do not repeat them here.

Fig. 3 has schematically provided the process flow diagram of the Fiber Bragg Grating Displacement Sensor method of the utility model embodiment.As shown in Figure 3, described method for sensing may further comprise the steps:

When (A1) external world has displacement, probe promotes the inclined-plane motion, the combination of the contact element at least two strain beams and the relative position information on described inclined-plane changes, it is different from the relative position on inclined-plane also to be that described contact element is in, as: the differing heights place on same inclined-plane, or a part of contact element is in, and another part is on the plane on the inclined-plane, or the equal height place on different inclined-planes, or the differing heights place on different inclined-planes; Thereby so that at least two fiber grating generation strains that are connected with strain beam respectively;

(A2) analyze the combination of the strain of described at least two fiber gratings, thereby know extraneous displacement, the sensitivity that this displacement is corresponding certain.

The benefit that reaches according to the utility model embodiment 1 is: use at least two fiber gratings, so that in the situation of same displacement, different wavelength variations is arranged, thus obtain different wavelength variations combinations, also be different sensitivity.

Embodiment 2:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Fig. 2 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 2, the first contact element on the first strain beam is when the bottom of (only tapered plane) slides into the summit from the inclined-plane, and the wavelength variations that is installed in the first fiber grating on the first strain beam is Δ λ _M1, also be that its maximum wavelength changes.When the second contact element on the second strain beam slided into the summit from the bottom on inclined-plane, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.

Above-mentioned the first and second contact elements are one in front and one in back to install, and spacing is L, and the length of the orthogonal projection on inclined-plane is a, and the initial position of the first contact element is the bottom on inclined-plane.

For above-mentioned slit gauge, range is R=L+a, if R＞2L, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

When 0≤x＜L, also be the range section for [0, L),

Also namely make up (y ₁, y ₂) in,

Only there is the first contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\ΔY}}{\mathrm{\Δx}}=\frac{\mathrm{\Δ}(y_1+y_2)}{\mathrm{\Δx}}=\frac{\mathrm{\Δ}{\mathrm{\λ}}_{m1}}{R-L}$

When L≤x≤R-L, also be that the range section is [L, R-L],

Also namely make up (y ₁, y ₂) in, $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-L}\&CenterDot;L\&le;y_1\&le;{\mathrm{\&lambda;}}_{m1},$ $0\&le;y_2<\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;(R-2L),$ The first and second contact elements all are on the inclined-plane; Sensitivity in this range section is:

When R-L＜x≤R, also be the range section for (R-L, R], y ₁=Δ λ _M1,

Also namely make up (y ₁, y ₂) in,

Only there is the second contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}.$

By the expression formula of sensitivity in each range section as can be known, can go to change sensitivity by adjusting each parameter, as increasing L to improve sensitivity.

For above-mentioned slit gauge, range is R=L+a, if R=2L, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

When 0≤x≤L, also be that the range section is [0, L],

Also namely make up (y ₁, y ₂) in, 0≤y ₁≤ Δ λ _M1, only have the first contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{L}$

When L＜x≤R, also be the range section for (L, R], y ₁=Δ λ _M1,

Also namely make up (y ₁, y ₂) in, 0＜y ₂≤ Δ λ m ₂, only have the second contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{L}.$

By the expression formula of sensitivity in each range section as can be known, the sensitivity that different range sections are corresponding different also can go to change sensitivity by adjusting each parameter, as reduces L to improve sensitivity.In whole range, synchronization only has a contact element to be on the inclined-plane.

Above-mentioned slit gauge is when work (corresponding to displacement sensing method), and process is:

(A1) record the combination (y of the wavelength variations of first, second fiber grating ₁, y ₂) (y ₁Corresponding to the positional information on main deviational survey face of the first contact element, y ₂And be sent to analysis module the positional information on auxiliary deviational survey face corresponding to the second contact element);

(A2) analysis module is according to above-mentioned wavelength variations y ₁, y ₂With the wavelength variations that obtains being suitable for and the relational expression of displacement, utilize this relational expression to know displacement x and sensitivity.

The benefit that reaches according to the utility model embodiment 2 is: use at least two fiber gratings, so that in the situation of same displacement, different wavelength variations is arranged, thus obtain different wavelength variations combinations, also be different sensitivity.Compared with prior art, in the identical situation of range, improve sensitivity, also increased the combination of sensitivity; In the identical situation of sensitivity, improved range.

Embodiment 3:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Fig. 4 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 4, the first contact element on the first strain beam is when the bottom of (only tapered plane) slides into the summit from the inclined-plane, and the wavelength variations that is installed in the first fiber grating on the first strain beam is Δ λ _M1, also be that its maximum wavelength changes.When the second contact element on the second strain beam slided into the summit from the bottom on inclined-plane, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.When the 3rd contact element on the 3rd strain beam slided into the summit from the bottom on inclined-plane, the wavelength variations that is installed in the 3rd fiber grating on the 3rd strain beam was Δ λ _M3, also be that its maximum wavelength changes.

Above-mentioned first, second, and third contact element is installed before and after being, spacing is respectively L ₁, L ₂, L=L ₁+ L ₂Length a less than the orthogonal projection on inclined-plane.The initial position of the first contact element is in the bottom on inclined-plane.

For above-mentioned slit gauge, range is R=L+a, and R＞2L, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Change y with the 3rd optic fiber grating wavelength ₃Be respectively with the relation of probe displacement x:

As 0≤x≤L ₁The time, also be that the range section is [0, L ₁],

y ₂=0, y ₃=0, also namely make up (y ₁, y ₂, y ₃) in,

Only there is the first contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2+y_3)}{\mathrm{\&Delta;x}}=\frac{{\mathrm{\&Delta;\&lambda;}}_{m1}}{R-L}$

Work as L ₁During＜x＜L, also be that the range section is (L ₁, L),

y ₃=0, also namely make up (y ₁, y ₂, y ₃) in, $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-L}\&CenterDot;L_1<y_1<\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-L}\&CenterDot;L,$ $0<y_2<\frac{{\mathrm{\&Delta;}\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;L_2,$ The first and second contact elements all are on the same inclined-plane; Sensitivity in this range section is:

When L≤x≤R-L, also be that the range section is [L, R-L], $y_1=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-L}\&CenterDot;x,$ $y_2=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;(x-L_1),$ $y_3=\frac{{\mathrm{\&Delta;\&lambda;}}_{m3}}{R-L}\&CenterDot;(x-L),$ Also namely make up (y ₁, y ₂, y ₃) in, $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-L}\&CenterDot;L\&le;y_1\&le;\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1},$ $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;L_2\&le;y_2\&le;\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;(R-L-L_1),$ $0\&le;y_3\&le;\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}\&CenterDot;(R-2L),$ First, second, and third contact element all is on the same inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2+y_3)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-L}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}$

As R-L＜x＜R-L+L ₁The time, also be that the range section is (R-L, R-L+L ₁), y ₁=Δ λ _M1, $y_2=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;(x-L_1),$ $y_3=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}\&CenterDot;(x-L),$ Also namely make up (y ₁, y ₂, y ₃) in, $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-L}\&CenterDot;(R-L-L_1)<y_2<\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2},$ $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}\&CenterDot;(R-2L)<y_3<\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}\&CenterDot;(R-L-L_2),$ The second and the 3rd contact element is on the inclined-plane; Sensitivity in this range section is:

Work as R-L+L ₁During≤x≤R, also be that the range section is [R-L+L ₁, R], y ₁=Δ λ _M1, y ₂=Δ λ _M2, $y_3=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}\&CenterDot;(x-L),$ Also namely make up (y ₁, y ₂, y ₃) in, $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3}}{R-L}\&CenterDot;(R-L-L_2)\&le;y_3\&le;\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m3},$ Only the 3rd contact element is on the inclined-plane; Sensitivity in this range section is:

By the expression formula of sensitivity in each range section as can be known, the sensitivity that different range sections are corresponding different also can go to change sensitivity by adjusting each parameter, as increasing L to improve sensitivity.

Embodiment 4:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Fig. 5 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 5, when the first contact element on the first strain beam slided into the summit from the bottom on the first inclined-plane, the wavelength variations that is installed in the first fiber grating on the first strain beam was Δ λ _M1, also be that its maximum wavelength changes.When the second contact element on the second strain beam slided into the summit from the bottom on the second inclined-plane, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.

Above-mentioned the first and second contact elements are one in front and one in back to install, the first inclined-plane and the second inclined-plane in tandem.The initial position of the second contact element is in the bottom on inclined-plane.

As shown in Figure 5, for above-mentioned slit gauge, range is R, if the first contact element and the first inclined-plane equal the length b of the orthogonal projection on the second inclined-plane, the wavelength variations y of the first fiber grating apart from a ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

When 0≤x＜b, also be the range section for [0, b), y ₁=0,

Also namely make up (y ₁, y ₂) in, 0≤y ₂＜Δ λ _M2, only have the second contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{b}$

When b≤x≤R, also be that the range section is [b, R],

y ₂=Δ λ _M2, also namely make up (y ₁, y ₂) in, 0≤y ₁≤ Δ λ _M1, only there is the first contact element to be on the inclined-plane, the sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-b}$

By the expression formula of sensitivity in each range section as can be known, the sensitivity that different range sections are corresponding different also can go to change sensitivity by adjusting each parameter.

As shown in Figure 6, for above-mentioned slit gauge, range is R, if the first contact element and the first inclined-plane apart from a ₁Orthogonal projection length a with the first inclined-plane ₂Sum is less than the length b (R=b) of the orthogonal projection on the second inclined-plane, then the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

As 0≤x≤a ₁The time, also be that the range section is [0, a ₁], y ₁=0, Also namely make up (y ₁, y ₂) in,

Only there is the second contact element to be on the inclined-plane; Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{b}$

Work as a ₁＜x＜a ₁+ a ₂The time, also be that the range section is (a ₁, a ₁+ a ₂),

Also namely make up (y ₁, y ₂) in, 0＜y ₁＜Δ λ _M1,

The first contact element and the second contact element all are on the inclined-plane; Sensitivity in this range section is:

Work as a ₁+ a ₂During≤x≤b, also be that the range section is [a ₁+ a ₂, b], y ₁=Δ λ _M1,

Also namely make up (y ₁, y ₂) in,

Only the second contact element is on the inclined-plane, and the sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{{\mathrm{\&Delta;\&lambda;}}_{m2}}{b}.$

By the expression formula of sensitivity in each range section as can be known, the identical sensitivity of different range section counterpart also can go to change sensitivity by adjusting each parameter, as reduces b to improve sensitivity.

Above-mentioned slit gauge is when work (corresponding to displacement sensing method), and process is:

(A1) record the combination (y of the wavelength variations of first, second fiber grating ₁, y ₂) (y ₁Corresponding to the positional information on main deviational survey face of the first contact element, y ₂And be sent to analysis module the positional information on auxiliary deviational survey face corresponding to the second contact element);

(A2) analysis module is according to above-mentioned wavelength variations y ₁, y ₂With the wavelength variations that obtains being suitable for and the relational expression of displacement, utilize this relational expression to know displacement x and sensitivity.

Embodiment 5:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Fig. 7 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 7, solid line partly is main deviational survey face, has 2 main deviational survey faces, and the angle of wedge on each inclined-plane is different; When the first contact element on the first strain beam slided into the summit from the bottom of main deviational survey face, the wavelength variations that is installed in the first fiber grating on the first strain beam was Δ λ _M1, also be that its maximum wavelength changes.

Dotted line is auxiliary deviational survey face, and when 1 inclined-plane only, the second contact element on the second strain beam slided into the summit from the bottom of auxiliary deviational survey face, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.Above-mentioned the first and second contact elements are to install side by side, and initial position all is in the bottom on inclined-plane.

For above-mentioned slit gauge, range is R, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

As 0≤x＜Δ x ₁The time, also be the range section for [0, Δ x ₁),

Also namely make up (y ₁, y ₂) in, 0≤y ₁＜Δ λ _M1,

The first contact element and the second contact element all are on the inclined-plane, and the sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{\mathrm{\&Delta;}{x}_1}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R}.$

As Δ x ₁During≤x≤R, also be that the range section is [Δ x ₁, R],

Also namely make up (y ₁, y ₂) in, 0≤y ₁≤ Δ λ _M1,

The first contact element and the second contact element all are on the inclined-plane, and the sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}\left(\right|y_1|+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-\mathrm{\&Delta;}{x}_1}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R}.$

By the expression formula of sensitivity in each range section as can be known, the sensitivity that different range sections are corresponding different also can go to change sensitivity by adjusting each parameter, as reduce Δ x ₁With improve the range section [0, Δ x ₁) interior sensitivity.In whole range, the first contact element relatively moves at 2 main deviational survey faces respectively, and the second contact element only relatively moves at an auxiliary deviational survey face.

Above-mentioned slit gauge is when work (corresponding to displacement sensing method), and process is:

(A1) record the combination (y of the wavelength variations of first, second fiber grating ₁, y ₂) (y ₁Corresponding to the positional information on main deviational survey face of the first contact element, y ₂And be sent to analysis module the positional information on auxiliary deviational survey face corresponding to the second contact element);

(A2) analysis module is according to above-mentioned wavelength variations y ₁, y ₂With the wavelength variations that obtains being suitable for and the relational expression of displacement, utilize this relational expression to know displacement x and sensitivity.

Embodiment 6:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Fig. 8 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 8, solid line partly is main deviational survey face, total a main deviational survey face, and the angle of wedge on each inclined-plane is identical; When the first contact element on the first strain beam slided into the summit from the bottom of main deviational survey face, the wavelength variations that is installed in the first fiber grating on the first strain beam was Δ λ _M1, also be that its maximum wavelength changes.

Dotted line is auxiliary deviational survey face, and when the second contact element on the second strain beam slided into the summit from the bottom of auxiliary deviational survey face, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.Above-mentioned the first and second contact elements are to install side by side, and initial position all is in the bottom on inclined-plane.

For above-mentioned slit gauge, range is R, and then the second optic fiber grating wavelength changes y ₂With the probe displacement x following relation is arranged:

$y_2=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R}\&CenterDot;x$

When the second optic fiber grating wavelength changes y ₂For

The time, the wavelength variations y of the first fiber grating ₁With the pass of probe displacement x be:

$y_1={(-1)}^{n-1}\frac{\mathrm{a\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R}\&CenterDot;x+\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}\&CenterDot;[\frac{1+{(-1)}^{n-1}}{2}+{(-1)}^n\&CenterDot;n]$

In the following formula, n is positive integer, represents the first contact element and is in from n main deviational survey face from left to right.In range section [0, R], the sensitivity of slit gauge is: Can go to improve sensitivity by the number a that increases main deviational survey face.In whole range, the first contact element relatively moves at a main deviational survey face respectively, and the second contact element only relatively moves at an auxiliary deviational survey face.

Above-mentioned slit gauge is when work (corresponding to displacement sensing method), and process is:

(A1) record the combination (y of the wavelength variations of first, second fiber grating ₁, y ₂) (y ₁Corresponding to the positional information on main deviational survey face of the first contact element, y ₂And be sent to analysis module the positional information on auxiliary deviational survey face corresponding to the second contact element);

(A2) analysis module is according to above-mentioned wavelength variations y ₂And Draw n, n is positive integer, and also namely this moment, the first contact element was in from which main deviational survey face from left to right;

Analysis module is basis again $y_1={(-1)}^{n-1}\frac{\mathrm{a\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R}\&CenterDot;x+\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}\&CenterDot;[\frac{1+{(-1)}^{n-1}}{2}+{(-1)}^n\&CenterDot;n]$ Process described wavelength variations y ₁, n, thereby know displacement x and sensitivity.

Embodiment 7:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Fig. 9 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 9, solid line partly is main deviational survey face, has 2 main deviational survey faces; When the first contact element on the first strain beam slided into the summit from the bottom of main deviational survey face, the wavelength variations that is installed in the first fiber grating on the first strain beam was Δ λ _M1, also be that its maximum wavelength changes.

Dotted line is auxiliary deviational survey face, has 2 auxiliary deviational survey faces, and when the second contact element on the second strain beam slided into the summit from the bottom of auxiliary deviational survey face, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.Above-mentioned the first and second contact elements are to install side by side, and initial position all is in the bottom on inclined-plane.

For above-mentioned slit gauge, range is R, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

As 0≤x＜Δ x ₁The time, also be the range section for [0, Δ x ₁),

Also namely make up (y ₁, y ₂) in, 0≤y ₁＜Δ λ _M1, Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}(y_1+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{\mathrm{\&Delta;}{x}_1}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{\mathrm{\&Delta;}{x}_2}.$

As Δ x ₁≤ x＜Δ x ₂The time, also be that the range section is [Δ x ₁, Δ x ₂),

Also namely make up (y ₁, y ₂) in, $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-\mathrm{\&Delta;}{x}_1}\&CenterDot;(R-\mathrm{\&Delta;}{x}_2)<y_1\&le;\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1},$ $\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{\mathrm{\&Delta;}{x}_2}\&CenterDot;{\mathrm{\&Delta;x}}_1\&le;y_2<\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2};$ Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}\left(\right|y_1|+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-\mathrm{\&Delta;}{x}_1}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{\mathrm{\&Delta;}{x}_2}.$

As Δ x ₂During≤x≤R, also be that the range section is [Δ x ₂, R],

Also namely make up (y ₁, y ₂) in,

0≤y ₂≤ Δ λ _M2Sensitivity in this range section is: $\frac{\mathrm{\&Delta;Y}}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}\left(\right|y_1|+y_2)}{\mathrm{\&Delta;x}}=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{R-\mathrm{\&Delta;}{x}_1}+\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{R-\mathrm{\&Delta;}{x}_2}.$

By the expression formula of sensitivity in each range section as can be known, the sensitivity that different range sections are corresponding different also can go to change sensitivity by adjusting each parameter, as reduce Δ x ₂With improve the range section [0, Δ x ₁) interior sensitivity.In whole range, the first contact element relatively moves at 2 main deviational survey faces respectively, and the second contact element also relatively moves at 2 auxiliary deviational survey faces respectively.

Above-mentioned slit gauge is when work (corresponding to displacement sensing method), and process is:

(A1) record the combination (y of the wavelength variations of first, second fiber grating ₁, y ₂) (y ₁Corresponding to the positional information on main deviational survey face of the first contact element, y ₂And be sent to analysis module the positional information on auxiliary deviational survey face corresponding to the second contact element);

(A2) analysis module is according to above-mentioned wavelength variations y ₁, y ₂With the wavelength variations that obtains being suitable for and the relational expression of displacement, utilize this relational expression to know displacement x and sensitivity.

Embodiment 8:

The application examples of fiber grating displacement sensor in slit gauge according to the utility model embodiment 1.

Figure 10 has schematically provided the structural representation of the slit gauge of the utility model embodiment.As shown in Figure 2, the first contact element on the first strain beam is (oblique cambered surface only from the inclined-plane, the cross section of this cambered surface is the one section arc that is on the circle, and radius is r) bottom when sliding into the summit, the wavelength variations that is installed in the first fiber grating on the first strain beam is Δ λ _M1, also be that its maximum wavelength changes.When the second contact element on the second strain beam slided into the summit from the bottom on inclined-plane, the wavelength variations that is installed in the second fiber grating on the second strain beam was Δ λ _M2, also be that its maximum wavelength changes.

Above-mentioned the first and second contact elements are one in front and one in back to install, and spacing is L, and the length of the orthogonal projection on inclined-plane is a, and maximum height is b, and the initial position of the first contact element is the bottom on inclined-plane.

For above-mentioned slit gauge, range is R=L+a, if R＞2L, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

When 0≤x＜L, also be the range section for [0, L), $y_1=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{b}\&CenterDot;[\sqrt{{\left(\frac{a^2+b^2}{2b}\right)}^2-{(a-x)}^2}-\frac{a^2-b^2}{2b}],$ y ₂=0, only there is the first contact element to be on the inclined-plane; The sensitivity of every bit is all different in this range section;

When L≤x≤R-L, also be that the range section is [L, R-L], $y_1=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{b}\&CenterDot;[\sqrt{{\left(\frac{a^2+b^2}{2b}\right)}^2-{(a-x)}^2}-\frac{a^2-b^2}{2b}],$ $y_2=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{b}\&CenterDot;[\sqrt{{\left(\frac{a^2+b^2}{2b}\right)}^2-{(a-x+L)}^2}-\frac{a^2-b^2}{2b}]$ The first and second contact elements all are on the inclined-plane; The sensitivity of every bit is all different in this range section;

When R-L＜x≤R, also be the range section for (R-L, R], y ₁=Δ λ _M1, $y_2=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{b}\&CenterDot;[\sqrt{{\left(\frac{a^2+b^2}{2b}\right)}^2-{(a-x+L)}^2}-\frac{a^2-b^2}{2b}],$ Only there is the second contact element to be on the inclined-plane; The sensitivity of every bit is all different in this range section.

By the expression formula of sensitivity in each range section as can be known, can go to change sensitivity by adjusting each parameter, as increasing L to improve sensitivity.

For above-mentioned slit gauge, range is R=L+a, if R=2L, the wavelength variations y of the first fiber grating ₁, the second optic fiber grating wavelength changes y ₂Be respectively with the relation of probe displacement x:

When 0≤x≤L, also be that the range section is [0, L], $y_1=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m1}}{b}\&CenterDot;[\sqrt{{\left(\frac{a^2+b^2}{2b}\right)}^2-{(a-x)}^2}-\frac{a^2-b^2}{2b}],$ y ₂=0, also namely make up (y ₁, y ₂) in, 0≤y ₁≤ Δ λ _M1, only have the first contact element to be on the inclined-plane; The sensitivity of every bit is all different in this range section;

When L＜x≤R, also be the range section for (L, R], y ₁=Δ λ _M1, $y_2=\frac{\mathrm{\&Delta;}{\mathrm{\&lambda;}}_{m2}}{b}\&CenterDot;[\sqrt{{\left(\frac{a^2+b^2}{2b}\right)}^2-{(a-x+L)}^2}-\frac{a^2-b^2}{2b}],$ Also namely make up (y ₁, y ₂) in, 0＜y ₂≤ Δ λ _M2, only have the second contact element to be on the inclined-plane; The sensitivity of every bit is all different in this range section.

Finding the solution of above-mentioned equation is the state of the art, as utilizes method of interpolation to find the solution.

By the expression formula of sensitivity in each range section as can be known, the sensitivity that different range sections are corresponding different also can go to change sensitivity by adjusting each parameter.

Above-mentioned slit gauge is when work (corresponding to displacement sensing method), and process is:

(A1) record the combination (y of the wavelength variations of first, second fiber grating ₁, y ₂) (y ₁Corresponding to the positional information on main deviational survey face of the first contact element, y ₂And be sent to analysis module the positional information on auxiliary deviational survey face corresponding to the second contact element);

(A2) analysis module is according to above-mentioned wavelength variations y ₁, y ₂With the wavelength variations that obtains being suitable for and the relational expression of displacement, utilize this relational expression to know displacement x and sensitivity.

What provide among above-described embodiment 2-8 all is displacement with respect to zero point (such as contact element all in the plane), can certainly calculate the displacement in the time period, computing method are: the last time point of described time period, first time point are poor with respect to the displacement at zero point, this computing method for those skilled in the art be hold intelligible.

Exemplarily provided the situation of two, three fiber gratings and strain beam among above-described embodiment 2-8, certainly can also be four or more than, measuring principle and above-described embodiment 2-8 have in essence identical, this is to hold intelligiblely for a person skilled in the art, and does not need to pay creative work can obtain on embodiment 2-8 basis.

Claims (6)

1. fiber grating displacement sensor, described displacement transducer comprises:

At least two fiber gratings, an end of described fiber grating is fixed, and the other end is installed in respectively on the different strain beams;

At least two strain beams, an end of described strain beam is fixed, and has the contact element that contacts with the inclined-plane on the strain beam;

The inclined-plane; In difference constantly, the combination of the positional information of contact element on the inclined-plane at least two strain beams has difference; When the external world had displacement, described contact element had on described inclined-plane and relatively moves, and the described strain beam of strain occured so that described fiber grating produces strain;

Probe, described probe is connected with described inclined-plane;

Analysis module, described analysis module obtains extraneous displacement according to the combination of the strain of described fiber grating.

2. displacement transducer according to claim 1, it is characterized in that: described inclined-plane is one, the contact element of described at least two strain beams divides the time to be located on described inclined-plane, perhaps is in respectively on the differing heights on described inclined-plane.

3. displacement transducer according to claim 1 is characterized in that: described inclined-plane is two or more, and the contact element of described at least two strain beams can relatively move on one or more inclined-planes respectively.

4. displacement transducer according to claim 3, it is characterized in that: at synchronization, only have a contact element to be on the inclined-plane, perhaps different contact elements is in respectively on the different inclined-planes.

5. displacement transducer according to claim 1, it is characterized in that: described inclined-plane is plane or curved surface.

6. according to claim 2 to 5 arbitrary described displacement transducers, it is characterized in that: described analysis module is used for knowing the residing range of extraneous displacement, sensitivity interval according to the combination of the strain of described fiber grating.

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