CN205808360U - A kind of receive strain magnitude Dynamic Optical Fiber strain sensing device - Google Patents

Abstract

This utility model disclose a kind of receive strain magnitude Dynamic Optical Fiber strain sensing device, laser instrument connects the first bonder, two light splitting ends of described first bonder connect one end of reference optical fiber and sensor fibre respectively, on described reference optical fiber, Polarization Controller is installed, the other end of described reference optical fiber and sensor fibre connects the second bonder, described second bonder connects data acquisition module, the signal that the output of described data acquisition module is gathered is to data processing module, the synchronization synchronizing trigger module triggers delivery outlet connecting laser and data acquisition module respectively.

Description

A kind of receive strain magnitude Dynamic Optical Fiber strain sensing device

Technical field

This utility model relates to strain sensing field, particularly relates to fiber strain sensing field.

Background technology

Traditional strain transducer is based on strain-electricity, and the signal of telecommunication and device thereof are easily by electromagnetic interference, wet The environmental effects such as degree, the most even cisco unity malfunction.Fiber strain sensing is then little affected by electromagnetic interference, environment Adaptability is extremely strong, and highly sensitive, it might even be possible to reach n ε rank, has unrivaled advantage in ultraprecise is monitored. Therefore, sensing system of fiber strain is a problem having very much application prospect and practical significance.Current strain magnitude of receiving is moved State fiber strain sensing apparatus structure is complicated, and cost of manufacture is high, it is difficult to meet production application demand.

Utility model content

Technical problem to be solved in the utility model be realize the high Dynamic Optical Fiber of a kind of simple in construction, certainty of measurement should Become sensing device.

To achieve these goals, the technical solution adopted in the utility model is: a kind of receive strain magnitude Dynamic Optical Fiber Strain sensing device, laser instrument connects the first bonder, and two light splitting ends of described first bonder connect reference optical fiber respectively With one end of sensor fibre, described reference optical fiber is provided with Polarization Controller, another of described reference optical fiber and sensor fibre End connects the second bonder, and described second bonder connects data acquisition module, and the output of described data acquisition module is gathered Signal triggers delivery outlet connecting laser and data acquisition module respectively to data processing module, the synchronization synchronizing trigger module.

Described laser instrument is the frequency stabilization narrow linewidth continuous wave laser of frequency-adjustable.

Described reference optical fiber and sensor fibre length are unequal.

This utility model is received and is strained the Dynamic Optical Fiber strain sensing apparatus structure of magnitude simply, is little affected by electromagnetic interference, Environmental suitability is strong, has the sensitivity of n ε rank, and can monitor strain variation the most in real time, can be used for heavy construction On-the-spot and great politics, economy, the circumference security protection in military base.

Accompanying drawing explanation

Labelling in the content expressed every width accompanying drawing in this utility model description below and figure is briefly described:

Fig. 1 is the Dynamic Optical Fiber strain sensing apparatus structure schematic diagram received and strain magnitude；

Labelling in above-mentioned figure is: 1, laser instrument；2, the first bonder；3, Polarization Controller；4, reference optical fiber；5, pass Photosensitive fibre；6, the second bonder；7, data acquisition module；8, data processing module；9, trigger module is synchronized.

Detailed description of the invention

As it is shown in figure 1, tunable laser 1 connects the first bonder 2, two light splitting ends of the first bonder 2 connect respectively Connecing reference optical fiber 4 and sensor fibre 5, wherein reference optical fiber 4 is provided with Polarization Controller 3, and the second bonder 6 is by reference optical fiber 4 Being combined into a branch of rear connection data acquisition module 7 with sensor fibre 5, data acquisition module 7 connects data processing module 8, synchronizes to touch The synchronization triggering delivery outlet sending out module 9 connects tunable laser 1 and data acquisition module 7 respectively.Tunable laser 1 is frequency Rate adjustable frequency stabilization narrow linewidth continuous wave laser 1.Reference optical fiber 4 and sensor fibre 5 length are unequal, and the difference of the two length is designated as L_h, L_h(such as L depending on applying according to reality_h=2 meters).

Above-mentioned receiving strains the Dynamic Optical Fiber strain sensing apparatus structure of magnitude simply, is little affected by electromagnetic interference, and environment is fitted Ying Xingqiang, has the sensitivity of n ε rank, and can monitor strain variation the most in real time.

Based on above-mentioned receive strain magnitude Dynamic Optical Fiber strain sensing device, method for sensing is: synchronize trigger module 9 drive Tunable laser 1 changes laser frequency, simultaneously drives data acquisition module 7 and gathers the second coupling under each laser frequency The signal of device 6 output, data processing module 8 is transported by the signal collected under each frequency the most in the same time does cross-correlation Calculate, find out the difference on the frequency making cross correlation value maximum, and then demodulate the strain that sensor fibre 5 detects.

Specifically: after building sensing device by this utility model, adjust Polarization Controller 3, make the second bonder 6 export Signal maximum and stable, synchronize the laser that trigger module 9 drives tunable laser 1 to send and produce f₀The frequency of (such as 1MHz) Moving, synchronization trigger module 9 simultaneously drives data acquisition module 7 and gathers M time (such as 500 times), gathers N number of (such as 500) point every time, It is designated as data (N, M), data is sent into and after data processing module 8 is averaged computing, obtains a point, be designated as P₁(f₀)

$P_1\left(f_0\right)=\frac{1}{N}\·\underset{i=1}{\overset{N}{\mathrm{\Σ}}}(\frac{1}{M}\·\underset{j=1}{\overset{M}{\mathrm{\Σ}}}data(i,j\left)\right)$

Repeat the above steps, makes laser be sequentially generated 2f₀, 3f₀..., kf₀Frequency displacement, obtain P₁(2f₀), P₁(3f₀) ..., P₁(kf₀)。

If external interference need to be detected act on the strain produced on sensor fibre 5, then repeat the above steps, obtain P₂(m), Wherein m=f₀,2f₀,3f₀,…,kf₀, order

$\left\{\begin{array}{c}{P}_1^{\′}(n-(t-1\left)f_0\right)=P_1\left(n\right)\\ P_2^{\′}(n-(t-1\left)f_0\right)=P_2(n-(t-1\left)f_0\right)\end{array}\right.$

$\left\{\begin{array}{c}{P}_3^{\′}(n-(t-1\left)f_0\right)=P_1(n-(t-1\left)f_0\right)\\ P_4^{\′}(n-(t-1\left)f_0\right)=P_2\left(n\right)\end{array}\right.$

Wherein, n=tf₀,(t+1)f₀,…,kf₀；T=1,2,3 ..., k-q；Q is constant (such as q=3), calculates P '₁With P ′₂, P '₃With P '₄Cross-correlation coefficient, be designated as

T₁(t)=corrcoef (P '₁,P′₂)

T₂(t)=corrcoef (P '₃,P′₄)

Find out T₁(t) and T₂T t that () is corresponding time maximum, if there being multiple such t, then takes being designated as of minimum

t₁=min (find (max (T₁)==T₁))

t₂=min (find (max (T₂)==T₂))

Then optimum frequency displacement is

Wherein, ξ is that sensor fibre 5 strains optical correction coefficient, and n is sensor fibre 5 fiber core refractive index, and c is light in vacuum Speed, then the fibre strain detected is

$\frac{{\mathrm{\ΔL}}_i}{L}=({\mathrm{\ΔL}}_{i-1}+\frac{\mathrm{\λ}\·t_{max}\·f_0}{c\·\mathrm{\ξ}}\·L_h)/L$

Wherein, Δ L_iIt is the optical-fiber deformation length that detects of i & lt, when L is detection strain, deforms upon the length of optical fiber Degree, λ is optical maser wavelength.

Above in conjunction with accompanying drawing, this utility model is exemplarily described, it is clear that this utility model implements and is not subject to The restriction of aforesaid way, as long as have employed changing of the various unsubstantialities that method of the present utility model is conceived and technical scheme is carried out Enter, or the most improved design of the present utility model and technical scheme are directly applied to other occasion, all at this utility model Protection domain within.

Claims (3)

1. one kind receive strain magnitude Dynamic Optical Fiber strain sensing device, it is characterised in that: laser instrument connects the first bonder, institute Two the light splitting ends stating the first bonder connect one end of reference optical fiber and sensor fibre respectively, and described reference optical fiber is provided with Polarization Controller, the other end of described reference optical fiber and sensor fibre connects the second bonder, and described second bonder connects number According to acquisition module, the signal that the output of described data acquisition module is gathered to data processing module, synchronize the synchronization of trigger module Trigger delivery outlet connecting laser and data acquisition module respectively.

The most according to claim 1 receive strain magnitude Dynamic Optical Fiber strain sensing device, it is characterised in that: described laser Device is the frequency stabilization narrow linewidth continuous wave laser of frequency-adjustable.

The most according to claim 1 and 2 receive strain magnitude Dynamic Optical Fiber strain sensing device, it is characterised in that: described Reference optical fiber and sensor fibre length are unequal.