CN112240744B - Optical fiber length calculation method, device, equipment and computer storage medium - Google Patents
Optical fiber length calculation method, device, equipment and computer storage medium Download PDFInfo
- Publication number
- CN112240744B CN112240744B CN201910642691.8A CN201910642691A CN112240744B CN 112240744 B CN112240744 B CN 112240744B CN 201910642691 A CN201910642691 A CN 201910642691A CN 112240744 B CN112240744 B CN 112240744B
- Authority
- CN
- China
- Prior art keywords
- data point
- determining
- pulse
- starting
- optical fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness
Abstract
The embodiment of the application relates to the technical field of optical communication, and discloses a method, a device and equipment for calculating the length of an optical fiber and computer storageA medium, the method comprising: determining a starting zero position X of a noise region zs (ii) a Determining a pulse set M; finding the position X from the set M of pulses zs Nearest data point position X f (ii) a When | X zs ‑X f |<th f Determining the position of Fresnel reflection and determining the length of the optical fiber according to the position of the Fresnel reflection, wherein th f Is a first preset distance threshold; or, when | X zs ‑X f |≥th f Then, determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d (ii) a According to the position X of the data point of the pulse falling edge d The fiber length is calculated. Through the mode, the embodiment of the application realizes that the optical fiber length is simple to measure, is not influenced by other factors, and has high measuring accuracy.
Description
Technical Field
The embodiment of the application relates to the technical field of optical communication, in particular to a method, a device, equipment and a computer storage medium for calculating the length of an optical fiber.
Background
Optical Time Domain Reflectometers (OTDRs) are used to test fiber optic cables, and typically include a laser diode that introduces pulses of Optical energy into the fiber at the proximal end of the fiber under test, and a photodiode that generates a current signal that is dependent on the power of the Optical energy emitted from the proximal end of the fiber in response to the input pulses.
Light energy is emitted from the proximal end of the fiber due to Fresnel reflections (Fresnel reflections) and backscattering (backscattering). Fresnel reflections are caused by abrupt changes in the refractive index of the optical pulse propagation medium, and typically such changes occur at junctions between lengths of optical fiber and breaks in the optical fiber. Backscatter is Rayleigh scattering (Rayleigh scattering) that returns in the opposite direction relative to the direction of the incoming pulse. Rayleigh scattering arises from the interaction between photons of the optical pulses introduced in the fiber and the molecules of the fiber. Rayleigh scattering causes inevitable power losses as the optical pulse propagates along the fiber, and therefore the power level of the backscattered light establishes the maximum distance that the pulse can propagate along the fiber without suffering unacceptable power losses. The power level of the backscattered light also provides diagnostic information, where the fiber is under stress and may therefore be susceptible to damage, the stress causing additional light attenuation resulting in a detectable change in the rate of decline of the backscattered signal.
In the process of implementing the embodiment of the present application, the inventors found that: currently, in the industry, optical fiber length measurement basically includes simply measuring the propagation time of fresnel reflection, calculating the fresnel reflection distance to obtain the optical fiber length, and implementing optical fiber length measurement through hardware modification.
Disclosure of Invention
In view of the above, embodiments of the present application provide a method, an apparatus, a device and a computer storage medium for calculating a length of an optical fiber, which overcome or at least partially solve the above problems.
According to an aspect of an embodiment of the present application, there is provided a method of calculating a length of an optical fiber, the method including:
determining a starting zero position X of a noise region zs ；
Determining a pulse set M;
finding the position X from the set M of pulses zs Nearest data point position X f ；
When | X zs -X f |<th f Determining the position of Fresnel reflection and determining the length of the optical fiber according to the position of the Fresnel reflection, wherein th f Is a first preset distance threshold; alternatively, the first and second electrodes may be,
when | X zs -X f |≥th f Determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the pulse falling edge data point d The fiber length is calculated.
Further, the starting zero point position X of the noise region is determined zs The method comprises the following steps:
starting data point position X from the optical fiber start Starting to search a data point with a signal value of 0;
when the data point with the first signal value of 0 is found, the position X of the data point is used i Counting signal values of subsequent data points for the starting point according to a first preset number;
counting the number of data points with a signal value of 0 in the first preset number of data points;
judging whether the number of the data points with the signal value of 0 is less than a first preset number threshold th zero If so, re-determining the fiber start data point position X start And searching the data point with the signal value of 0 again; otherwise, confirming the position X of the data point i Is the starting zero position X of the noise region zs 。
Further, the determining the pulse set M includes:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a second preset number;
sequentially calculating the difference value of the signal values of the second preset number of adjacent data points;
if all the difference values are greater than 0 and at least one difference value is greater than a first preset difference value threshold value, determining the starting data point as a pulse point, and putting the starting data point into a pulse set M;
updating the starting data point and continuing to determine the set of pulses as described above.
Further, the determining the position of the fresnel reflection includes:
determining signal values for all data points in the set M according to a linear regression baseline linear equation y ═ f (x);
when the signal value of the data point is greater than the linear regression fit value f (X) zs ) Then put the data point into a new set M 1 Until all data points in set M have been polled.
Further, the determining the position of the fresnel reflection further includes:
from the set M 1 Selecting a data point n with the data point position X ni When | X zs -X n When the value of | is minimum, the position X of the data point n is determined n Determined as the fresnel reflection location.
Further, the step of determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the data point of the pulse falling edge d Calculating a fiber length, comprising:
determining a set of pulse falling edges M 2 ；
From the set M 2 Is determined to be a distance X from the starting zero point position zs Location X of the nearest data point d ；
According to the position X of the data point of the pulse falling edge d The fiber length is calculated.
Further, the set M of falling edges of the determined pulse 2 The method comprises the following steps:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a third preset number;
sequentially calculating the difference value of the signal values of the third preset number of adjacent data points;
if all of the differences are less than 0, and at least one of the differences is less than a second predetermined difference thresholdThe value is determined, the starting data point is determined as the falling edge pulse point, and the starting data point is put into the falling edge pulse set M 2 ；
And updating the initial data point, and continuously determining the data point in the falling edge pulse set according to the steps.
The embodiment of the present invention further provides a device for calculating an optical fiber length, including:
a starting zero position determination module: starting zero position X for determining noise region zs ；
A pulse set determination module: for determining a set of pulses M;
a data point position determination module: for finding the position X from the set M of pulses zs Nearest data point position X f ；
An optical fiber length determination module: for finding the position X from the set M of pulses zs Nearest data point position X f When | X zs -X f |<th f Determining the length of the optical fiber according to the position of the Fresnel reflection; or, when | X zs -X f |≥th f Determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d (ii) a According to the position X of the data point of the pulse falling edge d Calculating the length of the optical fiber; wherein, the th f Is a first preset distance threshold.
Another embodiment of the present invention further provides an optical fiber length calculating apparatus, including: the system comprises a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface complete mutual communication through the communication bus;
the memory is used for storing at least one executable instruction, and the executable instruction causes the processor to execute the method for measuring the length of the optical fiber.
The embodiment of the present invention further provides a computer storage medium, where at least one executable instruction is stored in the storage medium, and the executable instruction causes a processor to execute the method for measuring the length of the optical fiber.
As can be seen from the above, in the embodiment of the present invention, by determining the initial zero point position of the noise region, two situations, namely the presence of fresnel reflection and the absence of fresnel reflection, are distinguished, and the measurement of the optical fiber length is performed in different manners, without any hardware modification on the OTDR device, so that the hardware cost is saved, the calculation process is completely based on the standard SOR file generated by the OTDR device, the length measurement is simple, and is not affected by any other devices, and the measurement accuracy is high.
The foregoing description is only an overview of the technical solutions of the embodiments of the present application, and the embodiments of the present application can be implemented according to the content of the description in order to make the technical means of the embodiments of the present application more clearly understood, and the detailed description of the present application is provided below in order to make the foregoing and other objects, features, and advantages of the embodiments of the present application more clearly understandable.
Drawings
Various additional advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:
FIG. 1 is a graph illustrating the attenuation curve of an optical fiber signal with Fresnel reflection pulses according to an embodiment of the present disclosure;
FIG. 2 is a graph showing the attenuation curve of an optical fiber signal without Fresnel reflection pulses according to an embodiment of the present disclosure;
FIG. 3 is a flow chart of a method for calculating fiber length according to an embodiment of the present disclosure;
FIG. 4 is a graph illustrating noise region versus fiber attenuation for an embodiment of the present application;
FIG. 5 is a flow chart illustrating the determination of the starting zero position of the noise region according to an embodiment of the present application;
FIG. 6 is a schematic diagram illustrating an attenuation curve of an optical fiber signal with a high loss point according to an embodiment of the present application;
FIG. 7 is a flow chart of a method for determining a set of pulses provided by an embodiment of the present application;
FIG. 8 is a schematic diagram showing the pulse region versus fiber signal attenuation curves for an embodiment of the present application;
FIG. 9 is a graph illustrating a linear regression of the effective fiber optic signal attenuation region according to an embodiment of the present application;
FIG. 10 is a flow chart of a method for determining a falling edge of a pulse provided in the practice of the present application;
FIG. 11 is a schematic structural diagram of an apparatus for calculating a length of an optical fiber according to an embodiment of the present disclosure;
fig. 12 is a schematic structural diagram of an embodiment of an optical fiber length calculating apparatus according to an embodiment of the present application.
Detailed Description
Exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
The two cases of fresnel reflection pulse and fresnel reflection pulse are mainly considered when measuring the length of the optical fiber, as shown in fig. 1, which is an optical fiber signal attenuation curve graph with fresnel reflection pulse according to the embodiment of the present application, and as shown in fig. 2, which is an optical fiber signal attenuation curve graph without fresnel reflection pulse according to the embodiment of the present application, wherein the X axis is a distance serial number (X) and represents a distance from 0 to a measurement maximum distance position, i.e., a distance of a sampling point of the OTDR device, the Y axis is an optical fiber signal attenuation dB value (Y), the sampling point of the OTDR device is referred to as a data point, a data point format of the optical fiber attenuation curve is [ distance serial number, signal value ], and the entire optical fiber signal curve is decreased with the increase of the X axis. The fresnel reflection location is the cable distal end face location where reflection and scattering are interrupted, so the signal behind this location is random noise, as shown in fig. 1 and 2, with frequent data points with signal dB values of 0.
Therefore, the embodiment of the application can measure the length of the optical fiber according to the two situations of the Fresnel reflection pulse and the Fresnel reflection pulse. Fig. 3 is a schematic flow chart of a method for calculating an optical fiber length according to an embodiment of the present disclosure.
Step 301: determining the starting zero point position X of the noise area in the optical fiber to be tested zs 。
Since the fresnel reflection position is the optical cable far-end surface position where reflection and scattering are interrupted, the signal after the position is random noise, there are data points with a dB value of 0 of the signal of the data point, the partial region we determine as a noise region, and the starting point of the noise region is the starting zero point. Fig. 4 shows the relationship between the noise region and the fiber attenuation curve, wherein the method for determining the starting zero point of the noise region can be as shown in fig. 5:
step 3011: searching a data point with a signal value of 0 from the position of the initial data point of the optical fiber;
at initialization, starting point X of data point is set start Set to 0, i.e., distance number 0. From X start Starting, gradually searching for the point with signal value of 0, and determining that the distance serial number is greater than X start And the first data point [ X ] for which the signal value y is 0 m ，Y m ]Wherein X is m Is a distance number, Y m Is the signal value.
the distance sequence number X of the first data point m At the initial point, counting the signal value Y in the first preset number of subsequent data points to obtain a signal [ Y [ ] m+1 ,Y m+2 ,Y m+3 ......,Y m+100 ]The first predetermined number is a predetermined number of subsequent data points, typically 50-150 data points, where we can set to 100.
Step 3013: counting the number n of data points with a signal value of 0 in the first preset number of data points;
it is assumed that in the above step, the first pre-stageLet the number be 100 and the acquisition position be X m To X m+99 Signal value [ Y ] of the data point of m+1 ,Y m+2 ,Y m+3 ......,Y m+100 ]Determining the signal value Y as 0 and the number of data points as n, and<100, such as: [ Y ] m+1 ,Y m+2 ,......,Y m+n ]。
Step 3014: judging whether the number n of the data points with the signal value of 0 is smaller than a first preset number threshold value or not;
assume that the first predetermined number threshold is th zero Then determine n and th zero If n is a magnitude relation of<th zero Resetting X without satisfying the requirement of noise region start Has a value of X m+1 Go back to step 3012; if n is greater than or equal to th zero Go to step 3015.
if n ≧ th zero Then the data point X m Satisfying the requirement of frequent zero point area and confirming the current X m Starting zero point for noise region, marked as X zs 。
Step 302: determining a pulse set M;
the pulse set M includes a plurality of data points, each data point being represented by (X, Y).
For special situations such as a high loss point and a medium loss point existing in a long-distance optical fiber, a signal attenuation curve may have many reflected pulses, and the signal characteristics of the pulses are similar to those of fresnel reflection, as shown in fig. 6, which is a schematic diagram of an optical fiber signal attenuation curve with a high loss point according to an embodiment of the present application, and therefore, it is necessary to complete identification and detection of all pulses.
The pulse position is determined by a six-point pulse determination method, as described in detail with reference to fig. 7.
Step 3021: acquiring signal values of subsequent data points according to a second preset quantity from the initial data point position of the optical fiber;
from the fiber starting data point position X start To begin, i.e. starting from the 0 point of the distance index, the data point [ X ] is determined i ，Y i ]Is a reference point, wherein, X i Is a distance number, Y i I is an integer greater than or equal to zero for the ith signal value.
Step 3022: sequentially calculating the difference value of the signal values of the second preset number of adjacent data points;
and determining the signal value of each subsequent data point according to a second preset number according to the determined reference point, such as: if the second preset number is 5 data points, five continuous data points [ X ] are determined after the reference point is determined i+1 ，Y i+1 ]，[X i+2 ，Y i+2 ]，[X i+3 ，Y i+3 ]，[X i+4 ，Y i+4 ]，[X i+5 ，Y i+5 ]。
Calculating the difference of the signal values between the adjacent data points of the five subsequent data points respectively by using the following formula:
Δj＝Y i+j -Y i
wherein j is an integer of 1 or more, and j is 1, 2, 3, 4 or 5.
The difference between the signal values of adjacent data points is denoted as Δ 1 ═ Y i+1 -Y i ，Δ2＝Y i+2 -Y i+1 ，Δ3＝Y i+3 -Y i+2 ，Δ4＝Y i+4 -Y i+3 ，Δ5＝Y i+5 -Y i+4 。
Step 3023: if all the difference values are greater than 0 and at least one difference value is greater than a first preset difference value threshold value, determining the starting data point as a pulse point, and putting the starting data point into a pulse set M;
if it is determined to be a pulse region, each data point needs to satisfy two conditions:
the first condition is as follows: Δ 1, Δ 2, Δ 3, Δ 4, Δ 5 all satisfy greater than 0;
and a second condition: at least one of Δ j is greater than a first predetermined difference threshold th pulse (Db units of signal difference threshold)
And if the data point area meeting the conditions I and II is determined as the pulse area, the initial data point is placed in the pulse set M. Fig. 8 is a schematic diagram of a relationship between a pulse region and an optical fiber signal attenuation curve according to an embodiment of the present application, in which a y-axis value is not zero and a region satisfying the first and second conditions is the pulse region.
Therefore, the datum point is a selected reference point, and five points are selected backwards for judgment by taking the datum point as a reference. And according to the continuity of the starting reference points of the pulse areas, carrying out boundary judgment and distinction on different pulse areas.
Step 3024: and judging whether all data points are traversed, if so, turning to a step 3025, and if not, updating the initial data point, and turning to a step 3021.
Judging whether all data points are traversed, if not, updating the initial data point to be the next data point [ X ] to be judged i+1 ，Y i+1 ]Then go to step 3021 to continue the determination.
Step 3025: the determination of the pulse set M is completed.
Determining a data point [ X ] with minimum distance from the starting zero point of the noise region from the pulse set M f ，Y f ]，X f The data point for which the distance is the smallest.
th f The first predetermined distance threshold is a data point, which may be, for example, 50-200 data points, the initial zero point X of the Fresnel reflection and noise region of the normal fiber attenuation curve zs Are the same.
As shown in fig. 9, which is a linear regression curve of the effective fiber signal attenuation region according to the embodiment of the present application, the region below the boundary is the data point of the signal value (y), and ideally, the noise region is 5-10 measurement point distances behind the fresnel reflection position.
When the Fresnel reflection is determined to exist, the position of the Fresnel reflection is determined through linear regression fitting of the attenuation curve of the optical fiber section, and the linear regression method mainly comprises the following steps: least squares and gradient descent. A fitted straight line is obtained according to linear regression, and the fitted straight line is named as a reference line K, where the linear equation of K is y ═ f (x), and as shown in fig. 9, the linear regression result is a linear regression result of the effective optical fiber signal attenuation region.
In practice, when the OTDR instrument is measuring, since the head leaves the machine room or the equipment, there will be a certain distance of higher attenuation section, and the noise area after the end of the fiber tail end does not belong to the effective fiber quality measurement area. Therefore, the effective fiber signal attenuation range is only the middle part of the head section and the tail section, and the linear regression of the fiber attenuation curve is only fit to the effective section.
According to practical experience and attenuation slope, calculating the starting position X of the effective region es Starting the zero point X with the noise region zs The effective area is [ X ] for the end position es ，X zs ]. For example, based on the preset attenuation slope, the start position X of the effective region is calculated es E.g. X es 1 kilometer (km), start zero X with noisy region zs Is the end position, so the effective area is [ X ] es ，X zs ]. And performing linear regression fitting in the effective region. For example, a determination is made as to whether the pulse is below the fit line, e.g., the pulse is below the fit line, the pulse is determined to be noise, and if the pulse is above the fit line, the pulse is determined to be a reflected signal.
The process of determining the fresnel reflection location may be as follows:
according to the initial zero point position X of the noise area determined in the step zs And determining the pulse set M determined in the previous step, and determining all data points { M } in the pulse set M 0 ，m 1 ，m 2 ，…，m i }，m i ＝[X i ，Y i ]Determining that Y is satisfied>f(X zs ) To form a new set M 1 I is a distance number, i is an integer greater than or equal to zero, X i Is a distance number, Y i Is the signal value. Until all data points in the set M are polled, a new set M is obtained 1
New set M determined according to the above 1 From the set M 1 Selecting a data point n with a distance sequence number Xn, and determining a set M 1 One data point n (i.e., [ Xn, Yn ]) of (1)]) So that | X zs -Xn | reaches a minimum, i.e. X, from the starting zero position in the data point zs The closest point is the position of the Fresnel reflection, X n Is a distance number, X n Is an integer of zero or more, and X n I is less than or equal to i, Yn is the signal value of the data point n. This minimum position X n As Fresnel reflection position, i.e. X n The fiber termination position is defined by the fiber length l ═ X n 。
As shown in fig. 2, a graph of the attenuation of an optical fiber signal without fresnel reflection pulses according to the embodiment of the present application shows that the fresnel reflection does not have a peak pulse, but still has a significant falling edge.
Specifically, when there is no fresnel reflection, it is necessary to be away from the initial zero point position X zs The position of the nearest pulse falling edge is specifically shown in fig. 10.
Step 3061: determining a set of pulse falling edges M 2 ；
Starting data point position X from the optical fiber start Initially, signal values for subsequent data points are acquired by a third predetermined number, such as: the third preset number is 5 data points, then the distance is fromStarting at point 0, determine a reference point [ X ] i ，Y i ]I is the distance number, X i Is a distance number, Y i I is an integer equal to or greater than zero as the signal value.
Five consecutive data points [ X ] after determination of the reference point i+1 ，Y i+1 ]，[X i+2 ，Y i+2 ]，[X i+3 ，Y i+3 ]，[X i+4 ，Y i+4 ]，[X i+5 ，Y i+5 ]。
And respectively calculating the y-axis difference value of the five subsequent data points and the reference point by adopting the following formula:
Δj＝Y i+j -Y i
wherein j is an integer of 1 or more, and j is 1, 2, 3, 4 or 5.
The difference between the signal values of adjacent data points is denoted as Δ 1 ═ Y i+1 -Y i ，Δ2＝Y i+2 -Y i+1 ，Δ3＝Y i+3 -Y i+2 ，Δ4＝Y i+4 -Y i+3 ，Δ5＝Y i+5 -Y i+4 。
The data point is a falling edge if the following two conditions are met:
the first condition is as follows: Δ 1, Δ 2, Δ 3, Δ 4, Δ 5 all satisfy less than 0;
and a second condition: at least one of Δ j is less than threshold th pulse (Db units of signal difference threshold)
Determining all data points satisfying the conditions one and two as a falling edge set M 2 。
Step 3062: from the set M 2 Is determined to be a distance X from the starting zero point position zs Location X of the nearest data point d ；
Determining a set of falling edges M 2 Data point d in (i.e. [ X ]) d ，Y d ])，X d Is the position of the data point d, Y d Is the signal value of data point d, d being an integer greater than or equal to zero, such that | X zs -X d I.e. determining the position X from the set of falling edges M2 to the starting zero point zs Nearest said pulse falling edge position X d I.e. minimum position x d The position of the falling edge closest to the starting zero of the noise region.
Step 3063: according to the position X of the pulse falling edge data point d Calculating the length of the optical fiber;
will be at a distance X from the starting zero point position zs Nearest pulse falling edge position X d When the termination position of the optical fiber is determined, the length l of the optical fiber is X d 。
In summary, in the embodiments of the present invention, the initial zero point position of the noise region is calculated, the presence and absence of fresnel reflection are distinguished by the pulse signal, and the length of the optical fiber is accurately calculated.
Fig. 11 is a schematic structural diagram of an optical fiber length calculating apparatus according to another embodiment of the present application. The apparatus 900 includes: a start zero position determination module 910, a pulse position determination module 920, a data point position determination module 930, and a fiber length determination module 940.
The start zero position determination module 910: starting zero position X for determining noise region zs ；
The pulse set determination module 920: for determining a set of pulses M;
the data point position determining module 930: for finding the position X from the starting zero point from the pulse set M zs Nearest data point position X f ；
The fiber length determination module 940: for finding the position X from the set M of pulses zs Nearest data point position X f When | X zs -X f |<th f Determining the length of the optical fiber according to the position of the Fresnel reflection; or, when | X zs -X f |≥th f Then, determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d (ii) a According to the position X of the pulse falling edge data point d Calculating the length of the optical fiber; wherein, the th f Is a first predetermined distance threshold.
Further, the start zero point position determining module 910 is further configured to determine the start data point position X from the optical fiber start Starting to search a data point with a signal value of 0;
when the data point with the first signal value of 0 is found, the position X of the data point is used i Counting signal values of subsequent data points for the starting point by a first preset number;
counting the number of data points with a signal value of 0 in the first preset number of data points;
judging whether the number of the data points with the signal value of 0 is less than a first preset number threshold th zero If so, re-determining the fiber start data point position X start And searching the data point with the signal value of 0 again; otherwise, confirming the position X of the data point i Is the starting zero position X of the noise region zs 。
Further, the pulse set determining module 920 is further configured to: starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a second preset number;
sequentially calculating the difference value of the signal values of the second preset number of adjacent data points;
if all the difference values are greater than 0 and at least one difference value is greater than a first preset difference value threshold value, determining the starting data point as a pulse point, and putting the starting data point into a pulse set M;
updating the starting data point and continuing to determine the set of pulses as described above.
Further, the fresnel reflection determination module 930 is further configured to determine signal values of all data points in the set M according to a linear regression reference linear equation y ═ f (x);
when the signal value of the data point is greater than the linear regression fit value f (X) zs ) When it is, thenPut the data point into a new set M 1 Until all data points in the set M are polled;
from the set M 1 Selecting a data point n with the data point position X ni When | X zs -X n When the value of | is minimum, the position X of the data point n is determined n Determined as the fresnel reflection location.
Further, the optical fiber length determining module 940 is further configured to: determining a set of pulse falling edges M 2 ；
From the set M 2 Is determined to be a distance X from the starting zero point position zs Location X of the nearest data point d ；
According to the position X of the pulse falling edge data point d The fiber length is calculated.
Further, the optical fiber length determining module 940 is further configured to: starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a third preset number;
sequentially calculating the difference value of the signal values of the third preset number of adjacent data points;
if all the difference values are less than 0 and at least one difference value is less than a second preset difference value threshold value, determining the starting data point as a falling edge pulse point, and putting the starting data point into a falling edge pulse set M 2 ；
And updating the initial data point, and continuously determining the data point in the falling edge pulse set according to the steps.
Compared with the prior art, the optical fiber length calculating device does not need to modify OTDR equipment on any hardware, saves hardware cost, is completely based on a standard SOR file generated by the OTDR equipment in the calculating process, is simple in length measurement, is not influenced by other equipment, and is high in measuring accuracy.
The embodiment of the present application provides a non-volatile computer storage medium, where at least one executable instruction is stored in the computer storage medium, and the computer executable instruction may execute the optical fiber length calculating method in any of the above method embodiments.
The executable instructions may be specifically configured to cause the processor to:
determining a starting zero position X of a noise region zs ；
Determining a pulse set M;
finding the position X from the set M of pulses zs Nearest data point position X f ；
When | X zs -X f |<th f Determining the position of Fresnel reflection and determining the length of the optical fiber according to the position of the Fresnel reflection, wherein th f A first preset distance threshold; alternatively, the first and second electrodes may be,
when | X zs -X f |≥th f Then, determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the data point of the pulse falling edge d The fiber length is calculated.
Further, the starting zero point position X of the noise region is determined zs The method comprises the following steps:
starting data point position X from the optical fiber start Starting to search a data point with a signal value of 0;
when the data point with the first signal value of 0 is found, the position X of the data point is used i Counting signal values of subsequent data points for the starting point according to a first preset number;
counting the number of data points with a signal value of 0 in the first preset number of data points;
judging whether the number of the data points with the signal value of 0 is less than a first preset number threshold th zero If so, re-determining the fiber start data point position X start And searching the data point with the signal value of 0 again; otherwise, confirming the position X of the data point i Is the starting zero position X of the noise region zs 。
Further, the determining the pulse set M includes:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a second preset number;
sequentially calculating the difference value of the signal values of the second preset number of adjacent data points;
if all the difference values are greater than 0 and at least one difference value is greater than a first preset difference value threshold value, determining the starting data point as a pulse point, and putting the starting data point into a pulse set M;
updating the starting data point and continuing to determine the set of pulses as described above.
Further, the determining the position of the fresnel reflection includes:
determining signal values for all data points in the set M according to a linear regression baseline linear equation y ═ f (x);
when the signal value of the data point is greater than the linear regression fit value f (X) zs ) Then put the data point into a new set M 1 Until all data points in set M have been polled.
Further, the determining the position of the fresnel reflection further includes:
from the set M 1 Selecting a data point n with the data point position X ni When | X zs -X n When the value of | is minimum, the position X of the data point n is determined n Determined as the fresnel reflection location.
Further, the determining of the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the data point of the pulse falling edge d Calculating a fiber length, comprising:
determining a set of pulse falling edges M 2 ；
From the set M 2 Is determined to be a distance X from the starting zero point position zs Position X of the nearest data point d ；
According to the position X of the pulse falling edge data point d The fiber length is calculated.
Further, the set of determined pulse falling edges M 2 The method comprises the following steps:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a third preset number;
sequentially calculating the difference value of the signal values of the third preset number of adjacent data points;
if all the difference values are less than 0 and at least one difference value is less than a second preset difference value threshold value, determining the starting data point as a falling edge pulse point, and putting the starting data point into a falling edge pulse set M 2 ；
And updating the initial data point, and continuously determining the data point in the falling edge pulse set according to the steps.
Compared with the prior art, when the method for calculating the length of the optical fiber is realized by the nonvolatile computer storage medium, the OTDR equipment does not need to be modified on any hardware, the hardware cost is saved, the calculation process is completely based on the standard SOR file generated by the OTDR equipment, the length measurement is simple, the method is not influenced by other parts, and the measurement accuracy is high.
Fig. 12 is a schematic structural diagram of an embodiment of an optical fiber length calculating device according to another embodiment of the present application, and the embodiment of the present application does not limit the specific implementation of the optical fiber length calculating device.
As shown in fig. 10, the optical fiber length calculating apparatus may include: a processor (processor)1002, a Communications Interface 1004, a memory 1006, and a Communications bus 1008.
Wherein: the processor 1002, communication interface 1004, and memory 1006 communicate with each other via a communication bus 1008. A communication interface 1004 for communicating with network elements of other devices, such as clients or other servers. The processor 1002 is configured to execute the program 1010, and may specifically execute the relevant steps in the above-described embodiment of the graph drawing method for an optical fiber length calculating apparatus.
In particular, the program 1010 may include program code that includes computer operating instructions.
The processor 1002 may be a central processing unit CPU, or an application Specific Integrated circuit asic, or one or more Integrated circuits configured to implement embodiments of the present application. The fiber length calculating device includes one or more processors, which may be the same type of processor, such as one or more CPUs; or may be different types of processors such as one or more CPUs and one or more ASICs.
The memory 1006 is used for storing the program 1010. The memory 1006 may comprise high-speed RAM memory, and may also include non-volatile memory (non-volatile memory), such as at least one disk memory.
The program 1010 may be specifically configured to cause the processor 1002 to perform the following operations:
determining a starting zero position X of a noise region zs ；
Determining a pulse set M;
finding the position X from the set M of pulses zs Nearest data point position X f ；
When | X zs -X f |<th f Determining the position of Fresnel reflection and determining the length of the optical fiber according to the position of the Fresnel reflection, wherein th f Is a first preset distance threshold; alternatively, the first and second electrodes may be,
when | X zs -X f |≥th f Determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the data point of the pulse falling edge d The fiber length is calculated.
Further, the starting zero point position X of the noise region is determined zs The method comprises the following steps:
starting data point position X from the optical fiber start Starting to search a data point with a signal value of 0;
when the data point with the first signal value of 0 is found, the position X of the data point is used i Counting signal values of subsequent data points for the starting point according to a first preset number;
counting the number of data points with a signal value of 0 in the first preset number of data points;
judging whether the number of the data points with the signal value of 0 is less than a first preset number threshold th zero If so, re-determining the fiber start data point position X start And searching the data point with the signal value of 0 again; otherwise, confirming the position X of the data point i Is the starting zero position X of the noise region zs 。
Further, the determining the pulse set M includes:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a second preset number;
sequentially calculating the difference value of the signal values of the second preset number of adjacent data points;
if all the difference values are greater than 0 and at least one difference value is greater than a first preset difference value threshold value, determining the starting data point as a pulse point, and putting the starting data point into a pulse set M;
updating the starting data point and continuing to determine the set of pulses as described above.
Further, the determining the position of the fresnel reflection includes:
determining signal values for all data points in the set M according to a linear regression baseline linear equation y ═ f (x);
when the signal value of the data point is greater than the linear regression fit value f (X) zs ) Then put the data point into a new set M 1 Until all data points in set M have been polled.
Further, the determining the position of the fresnel reflection further includes:
from the set M 1 Selecting a data point n with the data point position X ni When | X zs -X n When the value of | is minimum, the position X of the data point n is determined n Determined as the fresnel reflection location.
Further, the determination of the position of the starting zero point in the optical fiberPlacing X zs Nearest pulse falling edge data point position X d According to the position X of the data point of the pulse falling edge d Calculating a fiber length, comprising:
determining a set of pulse falling edges M 2 ；
From the set M 2 Is determined to be a distance X from the starting zero point position zs Location X of the nearest data point d ；
According to the position X of the pulse falling edge data point d The fiber length is calculated.
Further, the set M of falling edges of the determined pulse 2 The method comprises the following steps:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a third preset number;
sequentially calculating the difference value of the signal values of the third preset number of adjacent data points;
if all the difference values are less than 0 and at least one difference value is less than a second preset difference value threshold value, determining the starting data point as a falling edge pulse point, and putting the starting data point into a falling edge pulse set M 2 ；
And updating the initial data point, and continuously determining the data points in the falling edge pulse set according to the steps.
Compared with the prior art, the optical fiber length calculating equipment does not need to modify OTDR equipment on any hardware, saves the hardware cost, is completely based on the standard SOR file generated by the OTDR equipment in the calculating process, is simple in length measurement, is not influenced by other parts, and is high in measuring accuracy.
The algorithms or displays presented herein are not inherently related to any particular computer, virtual machine, or other apparatus. Various general purpose systems may also be used with the teachings herein. The required structure for constructing such a system will be apparent from the description above. In addition, embodiments of the present application are not directed to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the present application as described herein, and any descriptions of specific languages are provided above to disclose the best modes of the present application.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the application, various features of the embodiments of the application are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the application and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be construed to reflect the intent: this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this application.
Those skilled in the art will appreciate that the modules in the devices in an embodiment may be adaptively changed and arranged in one or more devices different from the embodiment. The modules or units or components of the embodiments may be combined into one module or unit or component, and furthermore they may be divided into a plurality of sub-modules or sub-units or sub-components. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.
Moreover, those skilled in the art will appreciate that while some embodiments herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the application and form different embodiments. For example, in the following claims, any of the claimed embodiments may be used in any combination.
It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The application may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names. The steps in the above embodiments should not be construed as limiting the order of execution unless specified otherwise.
Claims (10)
1. A method of calculating a length of an optical fiber, the method comprising:
measuring the length of the optical fiber under the condition of Fresnel reflection pulse, and determining the initial zero point position X of a noise area in the optical fiber to be measured zs (ii) a The noise region is a region where the dB value of the signal where the data point exists is 0; the starting point of the noise area is an initial zero point;
determining a pulse set M; the data points in the pulse set M are pulse points of a pulse area;
finding the position X from the set M of pulses zs Nearest data point position X f ；
When | X zs -X f |<th f Determining the position of Fresnel reflection and determining the length of the optical fiber according to the position of the Fresnel reflection, wherein th f Is a first preset distance threshold;
when | X zs -X f |≥th f Then, determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the pulse falling edge data point d The fiber length is calculated.
2. The method of claim 1, wherein the determining a starting zero position X of a noise region zs The method comprises the following steps:
starting data point position X from the optical fiber start Starting to search a data point with a signal value of 0;
when the data point with the first signal value of 0 is found, the position X of the data point is used i Counting signal values of subsequent data points for the starting point according to a first preset number;
counting the number of data points with a signal value of 0 in the first preset number of data points;
judging whether the number of the data points with the signal value of 0 is less than a first preset number threshold th zero If so, re-determining the fiber start data point position X start And searching the data point with the signal value of 0 again; otherwise, confirming the position X of the data point i Is the starting zero position X of the noise region zs 。
3. The method of claim 1, wherein the determining the set of pulses M comprises:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a second preset number;
sequentially calculating the difference value of the signal values of the second preset number of adjacent data points;
if all the difference values are greater than 0 and at least one difference value is greater than a first preset difference value threshold value, determining the starting data point as a pulse point, and putting the starting data point into a pulse set M;
and updating the initial data point, and continuously determining the data points in the pulse set according to the steps.
4. The method of claim 1, wherein the determining the location of the fresnel reflection comprises:
determining signal values for all data points in the set M according to a linear regression baseline linear equation y ═ f (x);
when the signal value of the data point is greater than the linear regression fit value f (X) zs ) Then put the data point into a new set M 1 Until all data points in the set M have been polled.
5. The method according to claim 4, wherein the determining the location of the Fresnel reflection further comprises:
from the set M 1 Selecting a data point n with the data point position X ni When | X zs -X n When the value of | is minimum, the position X of the data point n is determined n Determined as the fresnel reflection location.
6. The method of claim 1, wherein said determining said location X in said fiber from said starting zero point zs Nearest pulse falling edge data point position X d According to the position X of the data point of the pulse falling edge d Calculating a fiber length, comprising:
determining a set of pulse falling edges M 2 ；
From the set M 2 Is determined to be a distance X from the starting zero point position zs Location X of the nearest data point d ；
According to the position X of the pulse falling edge data point d The fiber length is calculated.
7. The method of claim 6, wherein the determining the set of pulse falling edges M 2 The method comprises the following steps:
starting data point position X from the optical fiber start Starting to acquire signal values of subsequent data points according to a third preset number;
sequentially calculating the difference value of the signal values of the third preset number of adjacent data points;
if all the difference values are less than 0 and at least one difference value is less than a second preset difference value threshold value, determining the starting data point as a falling edge pulse point, and putting the starting data point into a falling edge pulse set M 2 ；
And updating the initial data point, and continuously determining the data point in the falling edge pulse set according to the steps.
8. An optical fiber length calculating apparatus, comprising:
a starting zero position determination module: for measuring the length of an optical fiber in the presence of Fresnel reflection pulses, determining the starting zero position X of a noise region in the optical fiber to be measured zs (ii) a The noise region is a region where the dB value of the signal where the data point exists is 0; the starting point of the noise area is a starting zero point;
a pulse set determination module: for determining a set of pulses M; the data points in the pulse set M are pulse points of a pulse area;
a data point position determination module: for finding the position X from the set M of pulses zs Nearest data point position X f ；
An optical fiber length determination module: for finding the position X from the set M of pulses zs Nearest data point position X f When | X zs -X f |<th f Determining the length of the optical fiber according to the position of Fresnel reflection; when | X zs -X f |≥th f Determining the position X in the optical fiber from the starting zero point zs Nearest pulse falling edge data point position X d (ii) a According to the position X of the pulse falling edge data point d Calculating the length of the optical fiber; wherein, the th f Is a first preset distance threshold.
9. An optical fiber length calculating device comprising: the system comprises a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface complete mutual communication through the communication bus;
the memory is configured to store at least one executable instruction that causes the processor to perform the method of any one of claims 1-7.
10. A computer storage medium having stored therein at least one executable instruction that causes a processor to perform the method of any one of claims 1-7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910642691.8A CN112240744B (en) | 2019-07-16 | 2019-07-16 | Optical fiber length calculation method, device, equipment and computer storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910642691.8A CN112240744B (en) | 2019-07-16 | 2019-07-16 | Optical fiber length calculation method, device, equipment and computer storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112240744A CN112240744A (en) | 2021-01-19 |
| CN112240744B true CN112240744B (en) | 2022-08-23 |
Family
ID=74167066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910642691.8A Active CN112240744B (en) | 2019-07-16 | 2019-07-16 | Optical fiber length calculation method, device, equipment and computer storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112240744B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116756477B (en) * | 2023-08-23 | 2023-12-26 | 深圳市志奋领科技有限公司 | Precise measurement method based on Fresnel diffraction edge characteristics |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3138735C2 (en) * | 1981-09-29 | 1985-12-05 | Siemens AG, 1000 Berlin und 8000 München | Device for measuring the length of optical fibers |
| IT1245543B (en) * | 1991-05-14 | 1994-09-29 | Sip | TOOL FOR MEASURING THE LENGTH OF FIBER OPTICS. |
| KR100483147B1 (en) * | 2004-10-13 | 2005-04-14 | 한국표준과학연구원 | System and method for measuring length of optical fiber |
| US7808623B2 (en) * | 2007-10-15 | 2010-10-05 | Cisco Technology, Inc. | Measurement of optical fiber length and determination of chromatic dispersion over the optical fiber |
| CN103969027B (en) * | 2014-05-14 | 2016-09-07 | 东南大学 | A kind of inside of optical fibre loss/pip simply detects and localization method and device |
| CN108072504A (en) * | 2016-11-15 | 2018-05-25 | 上海朗研光电科技有限公司 | Breakpoints of optical fiber positioning and length measurement method based on high-speed single photon detector |
| CN106595492A (en) * | 2016-12-16 | 2017-04-26 | 威海北洋电气集团股份有限公司 | High resolution fiber length measurement device and method |
| CN106969714B (en) * | 2017-05-02 | 2019-07-09 | 中国航空工业集团公司北京长城计量测试技术研究所 | A kind of method of precise measurement optical fiber length |
-
2019
- 2019-07-16 CN CN201910642691.8A patent/CN112240744B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112240744A (en) | 2021-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9709460B2 (en) | Method and system for measuring an optical loss value of an optical fiber link | |
| US4838690A (en) | Simultaneous bi-directional optical time domain reflectometry method | |
| US20050259242A1 (en) | Accuracy automated optical time domain reflectometry optical return loss measurements using a "Smart" Test Fiber Module | |
| US5442434A (en) | Method for finding and measuring optical features using an optical time domain reflectometer | |
| EP3051266B1 (en) | Method and system for measuring an optical power attenuation value of a multimode device under test, receive device and computer-readable memory | |
| JP2014025921A (en) | Cross talk measuring method and cross talk measuring device | |
| JP2004264280A (en) | Method for measuring polarized light wave reflectivity | |
| US8400622B2 (en) | Enhanced OTDR sensitivity by utilizing mode-field diameter measurements | |
| US20230106273A1 (en) | Long-distance optical fiber detecting method, apparatus, device and system, and storage medium | |
| CN112240744B (en) | Optical fiber length calculation method, device, equipment and computer storage medium | |
| EP1005637B1 (en) | Methods for identifying optical fibers which exhibit elevated levels of polarization mode dispersion | |
| US9097615B2 (en) | Fiber signal loss event identification | |
| JP6896354B2 (en) | Optical pulse test device and optical pulse test method | |
| CN105784098A (en) | Optical fiber vibration detection method, device and system | |
| US7317518B2 (en) | Determination of an optical property of a DUT by OTDR measurement | |
| CN115343021A (en) | Ghost effect identification and elimination method and device and electronic equipment | |
| CN210183335U (en) | Single-axis optical fiber interferometer and positioning device for eliminating optical fiber vibration blind area | |
| CN210405317U (en) | Single-axis optical fiber interferometer and positioning device for eliminating optical fiber vibration blind area | |
| El-Sayed et al. | Investigation of the precision regarding fiber fault location with a commercial Optical Time Domain Reflectometer | |
| JP2013096734A (en) | Optical fiber diagnosis method | |
| JP2006078378A (en) | Method for measuring length in optical fiber | |
| CN112448756B (en) | Fresnel reflection peak positioning method and device and computing equipment | |
| WO2023042326A1 (en) | Connection loss difference measurement method, device, and program | |
| WO2021260913A1 (en) | Termination determining device, and termination determining method | |
| JP2023074152A (en) | Bending state estimation device, bending state estimation method and program |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |