An Axle Counter System Based on Fiber Bragg Grating

Abstract

The invention discloses an axle counting system based on fiber grating, comprising a processing unit, a modulation and demodulation unit and a track, wherein the interface of the processing unit is sequentially connected to a system terminal, a detection unit and a calibration unit, the second interface of the calibration unit is connected to the interface signal of the detection unit and is connected to the second interface signal of the first coupler, the first interface signal of the first coupler is connected to the frequency sweeping unit, the interface of the frequency sweeping unit is connected to the interface signal of the modulation and demodulation unit, the interface signal of the modulation and demodulation unit is connected to the optical fiber splicing box, the interface signal of the optical fiber splicing box is connected to the axle counting device, and the invention relates to the field of axle counting technology. The axle counting system based on fiber grating achieves the effects of accurate detection and elastic protection, has accurate and reliable detection, improves work efficiency, has elastic protection for sensors, avoids damage by external forces, and improves performance.

Description

Technical Field

[0001] The invention relates to the technical field of axle counting, and in particular to an axle counting system based on fiber grating. Background Art

[0002] The axle counting system is an important railway signaling equipment that uses wheel sensors to detect train wheel information and, after calculation, outputs section occupancy or idle information to the interlocking system.

[0003] At present, the wheel sensors of the axle counting system mainly use electromagnetic sensors, which are often interfered by surrounding factors, such as lightning strikes in rainy days, current induction, and electromagnetic interference, which seriously affect the application of electromagnetic sensors in electrification and high-speed trains.

[0004] In order to solve the application problems of the traditional wheel sensing system based on electromagnetic technology, fiber Bragg grating (FBG) sensing technology is introduced into the wheel detection application of high-speed railway. Since the rubber tire itself will also deform when rolling on the track, most traditional axle counting devices cannot accurately detect the running conditions of trams and trains with rubber wheels, and may even produce false detections. In addition, traditional axle counting devices cannot protect the fiber Bragg grating sensor well, and are easily damaged by external forces, reducing work efficiency and performance. Summary of the invention

[0005] 1. Technical issues to be solved

[0006] In view of the deficiencies in the prior art, the present invention provides an axle counting system based on fiber gratings, which solves the problem that most traditional axle counting devices cannot accurately detect the running conditions of trams and trains with rubber wheels, and may even produce false detections. In addition, traditional axle counting devices cannot better protect fiber grating sensors and are easily damaged by external forces, thereby reducing work efficiency and performance.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions: an axle counting system based on fiber grating, including a processing unit, a modulation and demodulation unit and a track, the processing unit is used to demodulate and process data, the modulation and demodulation unit is used to demodulate sensor signals, the interface of the processing unit is connected to the system terminal, the detection unit and the calibration unit in sequence, the first interface signal of the calibration unit is connected to the first coupler, the second interface of the calibration unit is connected to the interface signal of the detection unit and is connected to the second interface signal of the first coupler, the first interface signal of the first coupler is connected to the frequency scanning unit, the interface of the frequency scanning unit is connected to the interface signal of the modulation and demodulation unit, the interface signal of the modulation and demodulation unit is connected to the optical fiber splicing box, the interface signal of the optical fiber splicing box is connected to the axle counting device, and the axle counting device is buried in the track.

[0009] Preferably, the axle counting system of the grid is characterized in that the number of the detection units is several and they are evenly distributed.

[0010] Preferably, the detection unit comprises a first detector and a second coupler, and the first detector is signal-connected to the second coupler.

[0011] Preferably, the calibration unit comprises a second detector, an interface signal of the second detector is connected to an etalon, and an interface signal of the etalon is connected to a fiber Bragg grating.

[0012] Preferably, the two fiber grating sensors form an axle counting device, and the distance between the two fiber grating sensors in the axle counting device is fixedly equal.

[0013] Preferably, the material of the conical elastic member is set to be rubber.

[0014] Preferably, the axle counting device comprises a base, the base is buried on the rail, corresponding positions inside the top of the base are fixedly connected with conical elastic parts, and a fiber grating sensor is arranged at the inner center of the conical elastic part.

[0015] (III) Beneficial effects

[0016] The present invention provides an axle counting system based on fiber grating, which has the following beneficial effects:

[0017] (1) The fiber Bragg grating-based axle counting system is connected to the system terminal, the detection unit and the calibration unit in sequence through the interface of the processing unit. The first interface signal of the calibration unit is connected to the first coupler. The second interface of the calibration unit is connected to the interface signal of the detection unit and is connected to the second interface signal of the first coupler. The first interface signal of the first coupler is connected to the frequency sweeping unit. The interface of the frequency sweeping unit is connected to the interface signal of the modulation and demodulation unit. The interface signal of the modulation and demodulation unit is connected to the optical fiber splicing box. The effect of accurate detection is achieved. The structure is reasonable and simple, the use is convenient, the detection is accurate and reliable, and the work efficiency is greatly improved. The general axle counting system cannot detect the weight of the train, so as to judge whether it is the train or external interference.

[0018] (2) The fiber Bragg grating-based axle counting system is buried in the rail through a base. Conical elastic parts are fixedly connected to the corresponding positions on the top of the base. A fiber Bragg grating sensor is arranged at the central position inside the conical elastic part, achieving the effect of elastic protection. The structure is reasonable and simple, and it is easy to use. It has an elastic protection effect on the sensor to avoid damage by external forces, thereby greatly improving the performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural block diagram of the present invention;

[0020] Figure 2 It is the structural block diagram of the detection unit;

[0021] Figure 3 is the structural block diagram of the calibration unit;

[0022] Figure 4 Schematic diagram of the axle counting device structure.

[0023] In the figure: 1 processing unit, 2 modem unit, 3 track, 4 system terminal, 5 detection unit, 501 first detector, 502 second coupler, 6 calibration unit, 601 second detector, 602 standard tool, 603 fiber Bragg grating, 7 first coupler, 8 sweep unit, 9 fiber splicing box, 10 axle counting device, 101 substrate, 102 conical elastic member, 103 fiber Bragg grating sensor. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1-4The present invention provides a technical solution: an axle counting system based on fiber Bragg grating, comprising a processing unit 1, a modulation and demodulation unit 2 and a track 3, wherein the processing unit 1 is used for demodulating and processing data, and the modulation and demodulation unit 2 is used for demodulating sensor signals, and the interface of the processing unit 1 is sequentially connected to a system terminal 4, a detection unit 5 and a calibration unit 6, wherein the number of the detection units 5 is several and evenly distributed, and the detection unit 5 comprises a first detector 501 and a second coupler 502, and the first detector 501 is connected to the second coupler 502 by signal, and the calibration unit 6 comprises a second detector 601, and the interface signal of the second detector 601 is connected to an etalon 602, and the interface signal of the etalon 602 is connected to a fiber Bragg grating 603, and the fiber Bragg grating 603 forms a narrow-band filter or reflector in the fiber core, and the first interface signal of the calibration unit 6 is connected to the first coupler 7. The second interface of the calibration unit 6 is connected to the interface signal of the detection unit 5 and is connected to the second interface signal of the first coupler 7. The first interface signal of the first coupler 7 is connected to a frequency sweeping unit 8. The frequency sweeping unit 8 can improve the frequency sweeping rate and output linearity of the light source. The interface of the frequency sweeping unit 8 is connected to the interface signal of the modulation and demodulation unit 2. The interface signal of the modulation and demodulation unit 2 is connected to an optical fiber splicing box 9. The interface signal of the optical fiber splicing box 9 is connected to an axle counting device 10. The axle counting device 10 includes a base 101. The base 101 is buried on the rail 3. The corresponding positions of the top of the base 101 are fixedly connected with a conical elastic member 102. The material of the conical elastic member 102 is set to rubber material, which has a good elastic protection effect and low cost. A fiber grating sensor 103 is set at the central position of the conical elastic member 102. The axle counting device 10 is buried on the rail 3.

[0026] Two fiber grating sensors 103 form an axle counting device 10, and the distance between the two fiber grating sensors of the axle counting device 10 is fixedly equal. Figure 1As shown, when in use, first, on the track 3, the axle counting device 10 is used to divide the track 3 into several sections; when the wheel rolls over the axle counting device 10, the fiber grating sensor 103 buried in the conical elastic member 102 is deformed, and the central wavelength of the light wave passing through changes. The wavelength changes differently due to different rolling weights. The changed sensor signal is output to the modem unit 2 through the optical fiber connection box 9. The modem unit 2 cooperates with the sweep frequency unit 8 to perform sweep frequency decoding. The decoded signal is output to the first coupler 7, and then output to the calibration unit 6 and the detection unit 5 respectively. Several fixed frequency code segments are set in the calibration unit 6, and the number of detection units 5 is set corresponding to the number of fixed frequency code segments in the calibration unit 6. Each detection unit corresponds to a frequency segment. The calibration unit 6 compares and calibrates the decoded signal with the set fixed frequency code segment, and outputs it to the corresponding detection unit 5 and processing unit 1 respectively; the detection unit 5 finally transmits the detected signal to the processing unit 1, and the processing unit 1 calculates the number of axles of the vehicle passing through the axle counting device 10 based on the signals of the detection unit 5 and the calibration unit, and determines the direction, speed and weight of the vehicle, and outputs the information of the section being occupied or idle to the interlocking system. In addition, it determines whether it is a train or external interference based on the detected weight, and outputs alarm information to facilitate the judgment of maintenance personnel.

[0027] The fiber grating sensor 103 is buried in the conical elastic member 102. The conical elastic member 102 can be deformed significantly under external influences. The deformation of the elastic conical elastic member 102 enables the fiber grating sensor 103 to sensitively detect the deformation stress, thereby accurately detecting the operation of trams and trains with rubber wheels. Moreover, the conical elastic member 102 can also better protect the fiber grating sensor 103 to avoid damage due to external forces.

[0028] When in use, firstly, on the track 3, the fiber grating sensor 103 is used to divide the track 3 into sections. When the wheel rolls over the axle counter 10, the central wavelength of the fiber grating sensor 103 buried in the conical elastic member 102 changes, and the changed sensing signal is output to the modulation and demodulation unit 2 through the optical fiber connection box 9. The modulation and demodulation unit 2 demodulates the signal and outputs it to the sweep unit 8, and then outputs it to the first coupler 7, and then outputs it to the calibration unit 6 and the detection unit 5 respectively, and finally transmits it to the processing unit 1. The processing unit 1 calculates the number of axles of the vehicle passing through the axle counter 10 with the modulated pulse, The fiber grating sensor 103 can detect the number of wheels, the number of train trucks, and judge the direction, speed, health of the wheelset and the weight of the vehicle. During use, the fiber grating sensor 103 is buried in the conical elastic member 102. The conical elastic member 102 can be significantly deformed under the influence of the outside world. The deformation of the elastic conical elastic member 102 can enable the fiber grating sensor 103 to sensitively detect the deformation stress, thereby accurately detecting the running conditions of trams and trains with rubber wheels. Moreover, the conical elastic member 102 can also better protect the fiber grating sensor 103 to avoid damage due to external forces.

[0029] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".

[0030] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An axle counting system based on fiber Bragg grating, comprising a processing unit (1), a modulation and demodulation unit (2) and a track (3), wherein the processing unit (1) is used for demodulating processing data, and the modulation and demodulation unit (2) is used for demodulating sensor signals, characterized in that: The interface of the processing unit (1) is connected to the system terminal (4), the detection unit (5) and the calibration unit (6) in sequence; the first interface of the calibration unit (6) is connected to the first coupler (7); the second interface of the calibration unit (6) is connected to the interface of the detection unit (5) and is connected to the second interface of the first coupler (7); the first interface of the first coupler (7) is connected to the frequency sweeping unit (8); the interface of the frequency sweeping unit (8) is connected to the interface of the modulation and demodulation unit (2); the interface of the modulation and demodulation unit (2) is connected to the optical fiber splicing box (9); the interface of the optical fiber splicing box (9) is connected to the axle counting device (10); the axle counting device (10) is buried on the track (3); A plurality of fixed frequency code segments are set in the calibration unit (6); the number of detection units (5) is set corresponding to the number of fixed frequency code segments in the calibration unit (6); each detection unit corresponds to a frequency segment; the calibration unit (6) compares and calibrates the decoded signal with the set fixed frequency code segments and outputs them to the corresponding detection unit (5) and processing unit (1) respectively; the detection unit (5) finally transmits the detected signal to the processing unit (1).

2. The fiber grating based axle counting system according to claim 1, characterized in that: The number of the detection units (5) is several and they are evenly distributed.

3. The fiber grating based axle counting system according to claim 1, characterized in that: The detection unit (5) comprises a first detector (501) and a second coupler (502), and the first detector (501) is signal-connected to the second coupler (502).

4. The fiber grating based axle counting system according to claim 1, characterized in that: The calibration unit (6) comprises a second detector (601), the interface signal of the second detector (601) is connected to an etalon (602), and the interface signal of the etalon (602) is connected to a fiber Bragg grating (603).

5. The fiber grating based axle counting system according to claim 1, characterized in that: The axle counting device (10) further comprises a base (101), the base (101) being buried on the rail (3), the top of the base (101) being fixedly connected to corresponding positions thereof, and a fiber grating sensor (103) being arranged at the center of the conical elastic member (102).

6. The fiber grating based axle counting system according to claim 5, characterized in that: The two fiber grating sensors (103) form an axle counting device (10), and the distance between the two fiber grating sensors (103) in the axle counting device (10) is fixedly equal.

7. The fiber grating based axle counting system according to claim 5, characterized in that: The material of the conical elastic member (102) is set to be rubber.

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