CN108760114B

CN108760114B - Method and device for measuring rail force of railway track wheel

Info

Publication number: CN108760114B
Application number: CN201810804529.7A
Authority: CN
Inventors: 高亮; 肖宏; 周陈一; 吕宋; 杨晓
Original assignee: Beijing Jiaotong University
Current assignee: Beijing Jiaotong University
Priority date: 2018-07-20
Filing date: 2018-07-20
Publication date: 2023-10-31
Anticipated expiration: 2038-07-20
Also published as: CN108760114A

Abstract

The application provides a method and a device for measuring rail force of a railway track wheel, wherein the method for measuring the rail force of the railway track wheel comprises the following steps: acquiring first wheel track measurement data, second wheel track measurement data and third wheel track measurement data respectively acquired by a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor when a train passes through a railway track to be tested; acquiring a first wheel track correction strain and a second wheel track correction strain according to the first, second and third wheel track measurement data; and calculating the transverse force and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first and second wheel track correction strains and the relation between the first and second correction strains and the transverse force and the longitudinal force respectively acquired in advance. The method and the device can improve the accuracy and stability of monitoring the rail force of the rail wheel, and break through the bottleneck that the conventional testing means cannot realize long-term dynamic monitoring of the rail force of the rail wheel.

Description

Method and device for measuring rail force of railway track wheel

Technical Field

The application relates to the technical field of railway engineering monitoring methods, in particular to a method and a device for measuring rail force of a railway track wheel.

Background

With the continuous increase of the operation speed of high-speed railways, the interaction between the vehicles and the tracks is more and more severe, and great challenges are brought to the operation safety of the trains. Therefore, long-term monitoring is carried out aiming at wheel-rail interaction, and the method has very important significance for guaranteeing railway operation safety and improving long-term service performance of a rail system. The safety monitoring of wheel-rail interaction is based on the real-time capturing of wheel-rail vertical and lateral forces.

The applicant found in the study that in the prior art, the testing of the wheel track force is divided into a vehicle test and a ground test. The vehicle-mounted test is usually completed based on a special force measuring wheel set, so that higher measurement precision can be achieved, but the vehicle-mounted test has higher test cost, can only be used for periodic rail wheel and rail action relation detection, and is difficult to meet the requirement of all-weather safety service state monitoring of high-speed rails. The ground test generally utilizes a strain bridge to calculate dynamic wheel rail force by sticking a resistance strain gauge on a rail, and the method can ensure higher accuracy in short-term test, but because of the defect of the resistance sensing element in the aspects of water resistance, electromagnetic interference resistance, high temperature resistance, corrosion resistance and the like, coarse noise and baseline drift can be inevitably generated under long-term operation, and the stability and reliability of long-term monitoring are seriously affected.

Disclosure of Invention

Therefore, the application aims to provide a method and a device for measuring the rail force of a railway rail wheel, so as to improve the accuracy and the stability of monitoring the rail force of the railway rail wheel, realize the dynamic monitoring of the rail force of the wheel and provide reliable guarantee for the safe and stable running of a train.

In a first aspect, an embodiment of the present application provides a method for measuring rail force of a railway track wheel, where the method is applied to a rail force measuring device of a railway track wheel including a first fiber bragg grating sensor, a second fiber bragg grating sensor, and a third fiber bragg grating sensor, where the first fiber bragg grating sensor is used for being installed at a web of a railway track to be measured; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested, and the method comprises the following steps:

acquiring first wheel track measurement data, second wheel track measurement data and third wheel track measurement data respectively acquired by a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor when a train passes through the railway track to be tested;

acquiring first wheel track correction strain and second wheel track correction strain according to the first wheel track measurement data, the second wheel track measurement data and the third wheel track measurement data;

And calculating the transverse force and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first wheel track correction strain, the second wheel track correction strain and the relation between the first correction strain, the second correction strain, the transverse force and the longitudinal force of the wheel track, which are acquired in advance.

With reference to the first aspect, embodiments of the present application provide a first possible implementation manner of the first aspect, wherein: the linear relation between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively is obtained by the following method:

acquiring multiple groups of target measurement data acquired by a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor when different target transverse forces and different target longitudinal forces are respectively applied to a railway track to be tested; each set of target measurement data includes; first target measurement data, second target measurement data, and third target measurement data;

aiming at each group of target measurement data, acquiring a first target correction strain according to the first target measurement data and the second target measurement data; acquiring second target corrected strain according to the first target measurement data and the third target measurement data;

And acquiring linear relations between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively according to the first target corrected strain and the second target corrected strain corresponding to all target measurement data and the corresponding relation between the target transverse force and the target longitudinal force.

With reference to the first possible implementation manner of the first aspect, the embodiment of the present application provides a second possible implementation manner of the first aspect, where: the obtaining the linear relationship between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force respectively according to the first target corrected strain and the second target corrected strain corresponding to all the target measurement data and the corresponding relationship between the target lateral force magnitude and the target longitudinal force magnitude specifically includes:

and according to a pre-established linear relation formula between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively, carrying out linear fitting on the first target corrected strain and the second target corrected strain corresponding to all target measurement data, and the corresponding target transverse force and the corresponding target longitudinal force, and obtaining the linear relation between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively.

With reference to the second possible implementation manner of the first aspect, an embodiment of the present application provides a third possible implementation manner of the first aspect, where: the linear relation formula between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively satisfies the following formula (1):

(1)

wherein: epsilon' ₂ Representing a first corrected strain; epsilon' ₃ Representing a second corrected strain; f (F) _v Representing a longitudinal force; f (F) _l Representing a lateral force; A. b, C are fitting parameters.

With reference to the first possible implementation manner of the first aspect, an embodiment of the present application provides a fourth possible implementation manner of the first aspect, where: the method for acquiring the multiple groups of target measurement data acquired by the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor when different magnitudes of target transverse force and different magnitudes of target longitudinal force are respectively applied to the railway track to be measured specifically comprises the following steps:

applying target transverse forces or target longitudinal forces of different magnitudes to the railway track to be tested;

aiming at each time of applying a target transverse force or a target longitudinal force to the railway track to be tested, sampling by the first fiber bragg grating sensor according to a preset first sampling frequency to obtain first data under sampling, and taking the average value of the first data under sampling as the first target measurement data;

Synchronously sampling according to a preset second sampling frequency through the second fiber bragg grating sensor and the third fiber bragg grating sensor to obtain second data and third data under multiple sampling;

acquiring the average value of the second data under multiple sampling, and taking the average value of the second data under multiple sampling as the second target measurement data;

and acquiring the average value of the third data under multiple sampling, and taking the average value of the third data under multiple sampling as the third target measurement data.

In a second aspect, an embodiment of the present application provides a railway track wheel rail force measurement device, which is applied to a railway track wheel rail force measurement device including a first fiber bragg grating sensor, a second fiber bragg grating sensor, and a third fiber bragg grating sensor, where the first fiber bragg grating sensor is used for being installed at a rail web of a railway track to be measured; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested, and the device comprises:

the acquisition module is used for acquiring first wheel track measurement data, second wheel track measurement data and third wheel track measurement data respectively acquired by the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor when a train passes through the railway track to be tested;

The first calculation module is used for acquiring first wheel track correction strain and second wheel track correction strain according to the first wheel track measurement data, the second wheel track measurement data and the third wheel track measurement data;

and the second calculation module is used for calculating the transverse force of the wheel track and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first wheel track correction strain and the second wheel track correction strain and the relations between the pre-acquired first correction strain and the pre-acquired second correction strain and the transverse force and the longitudinal force respectively.

With reference to the second aspect, an embodiment of the present application provides a first possible implementation manner of the second aspect, where the apparatus further includes: a linear relation acquisition module;

the linear relation acquisition module is used for acquiring the linear relation between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively through the following method:

With reference to the first possible implementation manner of the second aspect, an embodiment of the present application provides a second possible implementation manner of the second aspect, where: the linear relation obtaining module is specifically configured to obtain a linear relation between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force respectively according to the first target corrected strain and the second target corrected strain corresponding to all target measurement data and a corresponding relation between the target lateral force and the target longitudinal force, by:

With reference to the second possible implementation manner of the second aspect, an embodiment of the present application provides a third possible implementation manner of the second aspect, where: the linear relation formula between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively satisfies the following formula (1):

(1)

With reference to the second aspect, embodiments of the present application provide a fourth possible implementation manner of the second aspect, wherein: the linear relation acquisition module is specifically configured to acquire multiple sets of target measurement data acquired when the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor apply different magnitudes of target transverse force and different magnitudes of target longitudinal force to the railway track to be measured respectively through the following steps:

When different magnitudes of target transverse force or target longitudinal force are applied to the railway track to be tested, sampling is carried out through the first fiber bragg grating sensor according to a preset first sampling frequency, first data under sampling are obtained, and the average value of the first data under sampling is used as the first target measurement data;

The method and the device for measuring the rail force of the railway track wheel provided by the embodiment of the application use the fiber bragg grating sensor as a main component for measurement; the fiber bragg grating sensor has the advantages of high detection sensitivity, high precision, long service life, long-term stability and the like, and the first fiber bragg grating sensor is respectively arranged on the rail web of the railway track to be detected; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested. When the measurement is carried out, first wheel track measurement data, second wheel track measurement data and third wheel track measurement data which are respectively acquired by a first fiber grating sensor, a second fiber grating sensor and a third fiber grating sensor when a train passes through a railway track to be measured are firstly acquired; then, according to the first, second and third wheel track measurement data, acquiring a first wheel track correction strain and a second wheel track correction strain; and calculating the transverse force and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first and second wheel track correction strains and the relation between the first and second correction strains and the transverse force and the longitudinal force respectively acquired in advance. By adopting the railway track wheel and rail force measuring method, the accuracy and the stability of track wheel and rail force monitoring can be improved, and the long-term dynamic monitoring of the wheel and rail force can be realized.

In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows an installation schematic diagram of a first fiber grating sensor, a second fiber grating sensor and a third fiber grating sensor in a railway track wheel rail force measuring device according to an embodiment of the present application;

FIG. 2 is a schematic diagram showing the connection of a railway track wheel rail force measuring device according to a first embodiment of the present application;

FIG. 3 shows a schematic diagram of a rail force measurement system for a railway track wheel provided by an embodiment of the present application;

fig. 4 is a schematic structural diagram of a protective housing provided outside a first fiber grating sensor, a second fiber grating sensor, and a third fiber grating sensor according to an embodiment of the present application;

Fig. 5 shows a flowchart of a method for measuring rail force of a railway rail wheel according to a second embodiment of the present application;

FIG. 6 is a flow chart illustrating a specific method for obtaining the relationship between the first and second corrected strains and the lateral and longitudinal forces, respectively, according to an embodiment of the present application;

FIG. 7 is a flowchart of a specific method for obtaining a linear relationship between a first corrected strain and a second corrected strain and a lateral force and a longitudinal force, respectively, according to the first target corrected strain and the second target corrected strain corresponding to all target measurement data and the corresponding relationship between the target lateral force magnitude and the target longitudinal force magnitude according to the third embodiment of the present application;

fig. 8 shows a schematic diagram of a rail force measuring device for a railway track wheel according to a fourth embodiment of the present application;

fig. 9 shows a schematic structural diagram of a computer device according to a fifth embodiment of the present application.

Illustration of: the device comprises a processor 10, a fiber bragg grating modulator 20, a railway track 30 to be tested, a waterproof layer 40 and a protective shell 50;

a first fiber grating sensor FBG1, a second fiber grating sensor FBG2 and a third fiber grating sensor FBG3.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present application.

The current wheel rail force test is divided into a vehicle test and a ground test. The vehicle-mounted test is usually completed based on a special force measuring wheel set, so that higher measurement precision can be achieved, but the vehicle-mounted test has higher test cost, can only be used for periodic rail wheel and rail action relation detection, and is difficult to meet the requirement of all-weather safety service state monitoring of high-speed rails. The method can ensure higher precision in short-term test, but because the resistance sensing element has the defects of water resistance, electromagnetic interference resistance, high temperature resistance, corrosion resistance and the like, coarse noise and baseline drift can be inevitably generated under long-term operation, and the stability and reliability of long-term monitoring are seriously affected.

For the convenience of understanding the present embodiment, a device for measuring rail force of a railway track wheel disclosed in the present embodiment will be described in detail. The measuring device for the rail force of the railway track wheel has two specific functions:

(1) The method is used for establishing a corresponding relation between the railway track strain and the railway track wheel rail force; here, since the railway track wheel rail force can be generally decomposed into a horizontal lateral force and a vertical downward longitudinal force, the correspondence between the railway track strain and the railway track wheel rail force is characterized by the relationship between the railway track strain and the lateral force, the longitudinal force.

The corresponding relation between the railway track strain and the railway track wheel rail force is established by respectively applying different transverse forces and different longitudinal forces to the railway track, and calibrating the corresponding relation between the railway track strain and the railway track wheel rail force based on the applied longitudinal forces and transverse forces and the corresponding railway track strain when the force is applied; the calibration process can be performed in a simulation scene, namely, the calibration is performed aiming at the railway track to be tested installed on the simulation site; the calibration can also be carried out on site, i.e. directly on railway tracks which have been installed on the railway and are actually to be put into operation or have been put into operation.

When the calibration process is performed in a simulation scene, the used railway track to be measured is consistent with the specifications, materials, processes and the like of the railway track to be measured which are really measured; meanwhile, the measuring device for the rail force of the railway track wheel for calibration is identical to the measuring device for the rail force of the railway track wheel which is actually used for realizing measurement.

When the calibration process is carried out on site, after the corresponding relation between the railway track strain and the railway track wheel rail force is established, the measuring device of the railway track wheel rail force used in the calibration process can be directly used for measuring the wheel rail force of the railway track to be measured in the actual operation process without being disassembled after the calibration is finished.

(2) The device is used for being installed in a railway track to be tested which is actually put into operation, and measuring wheel rail force of the railway track to be tested.

Referring to fig. 1 and 2, a railway track wheel rail force measuring device provided by an embodiment of the present application includes a first fiber bragg grating sensor FBG1, a second fiber bragg grating sensor FBG2, a third fiber bragg grating sensor FBG3, and a processor 10.

The first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2 and the third fiber bragg grating sensor FBG3 are all connected with the processor connection 10;

The first fiber bragg grating sensor is used for being installed on the rail web of the railway track to be tested; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested.

The processor is used for establishing the relation between the first correction strain and the second correction strain and the transverse force and the longitudinal force respectively according to the measurement data obtained when the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor apply the target transverse force with different magnitudes and the target longitudinal force with different magnitudes to the railway track to be tested respectively, or

And calculating the wheel rail force of the railway rail to be tested according to the measurement data obtained by the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor when the train passes through the railway rail to be tested and the established relation between the first correction strain and the second correction strain and the transverse force and the longitudinal force respectively.

In addition, referring to fig. 2, in the railway track wheel rail force measuring device provided by the embodiment of the present application, a fiber bragg grating regulator 20 is respectively connected between the processor 10 and the first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2, and the third fiber bragg grating sensor FBG 3;

The fiber bragg grating mediator is used for respectively converting measurement data transmitted by the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor from optical signals into electrical signals and transmitting the electrical signals to the processor.

The embodiment of the application uses the fiber bragg grating sensor as a main component for measuring the wheel rail force; the fiber bragg grating sensor has the advantages of high detection sensitivity, high precision, long service life, long-term stability and the like, and the first fiber bragg grating sensor is used for being installed at the rail web of the railway track to be detected; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested. When the train passes through the railway track to be measured, the processor can calculate the transverse force and the longitudinal force of the wheel track applied to the railway track to be measured when the train passes through the railway track to be measured according to the measurement data respectively acquired by the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor when the train passes through the railway track to be measured. By adopting the railway track wheel and rail force measuring device, the accuracy and stability of track wheel and rail force monitoring can be improved, and long-term dynamic monitoring of the wheel and rail force can be realized.

In addition, referring to fig. 1 to 3, an embodiment of the present application further provides a railway track wheel rail force measurement system, including: the railway track wheel rail force measuring device as in the above embodiment, further comprising: a railway track 30 to be tested;

wherein, the first fiber bragg grating sensor FBG1 is arranged at the rail web of the railway track 30 to be tested; the second fiber bragg grating sensor FBG2 is arranged at the upper corner of the rail bottom of the railway rail 30 to be tested; the third fiber bragg grating sensor FBG3 is installed at the center of the rail bottom of the railway rail 30 to be tested.

For accurate measurement, the first fiber grating sensor FBG1, the second fiber grating sensor FBG2 and the third fiber grating sensor FBG3 are all installed in the middle of a railway track 30 to be measured, and the plane where the midpoints of the first fiber grating sensor FBG1, the second fiber grating sensor FBG2 and the third fiber grating sensor FBG3 are located is parallel to the longitudinal section of the railway track 30 to be measured, which is perpendicular to the axis of the railway track 30 to be measured.

When the first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2 and the third fiber bragg grating sensor FBG3 are installed on a railway track to be tested, firstly, the position of the railway track to be tested, where each sensor is installed, is selected, the surface of the railway track to be tested is polished, the sensors are stuck to the polished position of the railway track to be tested, and the surfaces of the first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2, the third fiber bragg grating sensor FBG3 and the railway track to be tested are integrally stuck and fixed.

Optionally, since the glue used is aged along with the external natural conditions after the sensor is adhered to the railway track to be tested and is thus lost in viscosity, in order to achieve firm adhesion of the first fiber grating sensor FBG1, the second fiber grating sensor FBG2 and the third fiber grating sensor FBG3, both ends of the first fiber grating sensor, the second fiber grating sensor and the third fiber grating sensor are welded to the surface of the railway track to be tested.

In addition, since the welding points of the first fiber grating sensor, the second fiber grating sensor and the third fiber grating sensor with the railway track to be tested are easily oxidized by external rainwater and air, a waterproof layer 40 may be further provided outside the welding positions of the two ends of the first fiber grating sensor, the second fiber grating sensor and the third fiber grating sensor with the surface of the railway track to be tested, as shown in fig. 3.

In the application, as shown in fig. 1, a first fiber bragg grating sensor FBG1 is used for being installed at the rail web of a railway track to be tested; the second fiber bragg grating sensor FBG2 is used for being arranged at the upper corner of the rail bottom of the railway rail to be tested; the third fiber bragg grating sensor FBG3 is used for being installed at the center of the rail bottom of the railway rail to be tested.

When the railway track to be measured is installed, the extending direction of the axes of the first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2 and the third fiber bragg grating sensor FBG3 is consistent with the extending direction of the axes of the railway track to be measured.

Specifically, because the installation position has a certain error in the actual installation process, the rail web of the railway rail to be detected is generally regarded as the rail web of the railway rail to be detected within a certain range; the rail bottom center of the railway rail to be measured is regarded as the rail bottom of the railway rail to be measured in a certain range, and the rail bottom upper angle of the railway rail to be measured is regarded as the rail bottom upper angle of the railway rail to be measured in a certain range.

In another embodiment of the present application, in order to protect the first fiber grating sensor FBG1, the second fiber grating sensor FBG2 and the third fiber grating sensor FBG3 from various losses or damage during long-term use, a protection housing 50 may be further disposed outside the first fiber grating sensor, the second fiber grating sensor and the third fiber grating sensor, as shown in fig. 4.

In addition, in order to establish a correspondence between the railway track strain and the railway track wheel rail force, in the embodiment of the present application, the method further includes: a jack (not shown);

The jack is used for applying target transverse forces with different magnitudes and target longitudinal forces with different magnitudes to the railway track to be tested; target lateral force F as in fig. 1 and 3 _l And a target longitudinal force F _v 。

The first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2 and the third fiber bragg grating sensor FBG3 are further used for acquiring measurement data when the jack applies different magnitudes of target transverse force and different magnitudes of target longitudinal force to the railway track to be measured;

the processor 30 is further configured to obtain measurement data according to the first fiber grating sensor FBG1, the second fiber grating sensor FBG2, and the third fiber grating sensor FBG3 when the jack applies different magnitudes of target lateral force and different magnitudes of target longitudinal force to the railway track to be tested, and establish relationships between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force, respectively.

In addition, in order to obtain the target lateral force and the target longitudinal force applied by the jack, the road wheel rail force system provided by the embodiment of the application further comprises: a pressure sensor (not shown);

the pressure sensor is arranged between the jack and the railway track to be tested and is used for acquiring the applied target transverse force and the applied target longitudinal force when the jack applies the target transverse force and the target longitudinal force with different magnitudes to the railway track to be tested.

The pressure sensor is also connected with a dynamic acquisition instrument (not shown in the figure);

the dynamic acquisition instrument is used for automatically reading the magnitudes of transverse force and longitudinal force from the pressure sensor.

The processor 30 can then establish a relationship between the first corrected strain and the second corrected strain and the lateral and longitudinal forces, respectively, based on the lateral and longitudinal forces read by the dynamic acquisition instrument and the measured data measured by the first, second, and third fiber grating sensors.

After the relation between the first correction strain and the second correction strain and the transverse force and the longitudinal force are established, the wheel track force of the railway track to be measured can be calculated according to the measurement data obtained by the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor when the train passes through the railway track to be measured and the established relation between the first correction strain and the second correction strain and the transverse force and the longitudinal force respectively.

Referring to fig. 5, a second embodiment of the present application further provides a method for measuring rail force of a railway rail wheel, where the method uses the rail force measuring device for a railway rail wheel provided by the embodiment of the present application, and the method specifically includes:

S501: the method comprises the steps of acquiring first wheel track measurement data, second wheel track measurement data and third wheel track measurement data respectively acquired by a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor when a train passes through a railway track to be tested.

Here, the first fiber bragg grating sensor is used for being installed on the rail web of the railway track to be tested; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested.

As shown in fig. 1, a specific installation example of a first fiber grating sensor, a second fiber grating sensor, and a third fiber grating sensor is provided:

taking the center of a midspan section of a railway track to be tested as an origin O, taking the direction of transverse force application as an x-axis, taking the direction of longitudinal force application as a longitudinal axis, and taking the extending direction of the railway track to be tested as a z-axis, so as to establish a coordinate system; the distance from the origin O to the foot is c and the distance from the origin O to the head is h.

The first fiber bragg grating sensor FBG1 is arranged at the rail web of the railway track to be tested, the axis of the fiber core is parallel to the z axis, and the x axis passes through the axis of the fiber core; the second fiber bragg grating sensor FBG2 is arranged at the upper corner of the rail bottom, the distance between the second fiber bragg grating sensor and the x axis is a, and the distance between the second fiber bragg grating sensor and the y axis is b; a third fiber grating sensor FBG3 is mounted at the rail foot, at a distance c from the x-axis.

As the train passes over the railway track under test, the wheel-rail forces applied to the railway track can be broken down into wheel-rail transverse forces and wheel-rail longitudinal forces. Wherein the direction of the lateral force of the wheel track is the side of the train, applied towards the other side, which is equivalent to the lateral force F in FIG. 1 _l 。

When the train passes through the railway track to be tested, acting force is generated on the track to enable the track to generate strain, at the moment, the three fiber grating sensors stuck on the track can detect the strain of the railway track to be tested, and first wheel track measurement data, second wheel track measurement data and third wheel track measurement data which are respectively acquired by the first fiber grating sensor, the second fiber grating sensor and the third fiber grating sensor when the train passes through the railway track to be tested are acquired.

The first wheel track measurement data, the second wheel track measurement data and the third wheel track measurement data are measurement data obtained when the first fiber bragg grating sensor, the second fiber bragg grating sensor and the third fiber bragg grating sensor in the first embodiment apply different amounts of target transverse force and different amounts of target longitudinal force to the railway track to be measured respectively.

S502: acquiring a first wheel track correction strain and a second wheel track correction strain according to the first wheel track measurement data, the second wheel track measurement data and the third wheel track measurement data;

when the method is specifically realized, the first fiber bragg grating sensor is arranged at the rail web of the railway rail to be measured, the extending direction of the fiber core of the first fiber bragg grating sensor is consistent with the extending direction of the rail to be measured, at the moment, the strain generated by the first fiber bragg grating sensor is very tiny due to the transverse force and the longitudinal force, and the measured first wheel rail measurement data reflects the influence of the thermal expansion and the cold contraction of the rail to be measured on the strain of the railway rail to be measured caused by the temperature change.

The second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway rail to be tested, and the transverse force and the longitudinal force of the wheel rail can influence the measured second wheel rail measurement data except the air temperature change.

The third fiber bragg grating sensor is arranged at the rail bottom of the railway rail to be tested, and only the longitudinal force of the wheel rail can influence the measured third wheel rail measurement data except the air temperature change, so that the influence of the transverse force of the wheel rail on the measured third wheel rail measurement data is negligible.

Therefore, after the influence of the temperature on the strain of the railway track in the second wheel track measurement data and the third wheel track measurement data is eliminated, the rest is the influence part of the wheel track transverse force and the wheel track longitudinal force.

Therefore, when the first wheel-track-correction strain and the second wheel-track-correction strain are acquired based on the first wheel-track measurement data, the second wheel-track measurement data, and the third wheel-track measurement data, the first wheel-track-correction strain is actually the strain after the influence of the temperature on the strain of the railway track in the second wheel-track measurement data is eliminated, and the second wheel-track-correction strain is actually the strain after the influence of the temperature on the strain of the railway track in the second wheel-track measurement data is eliminated.

Specifically, the first wheel-track-correction strain may be obtained by taking the difference between the second wheel-track measurement data and the first wheel-track measurement data; the second wheel track correction strain is obtained by taking the difference between the third wheel track measurement and the first wheel track measurement.

S503: and calculating the transverse force of the wheel track and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first wheel track correction strain and the second wheel track correction strain and the relations between the first correction strain and the second correction strain, the transverse force and the longitudinal force of the wheel track, which are acquired in advance.

When the method is specifically realized, the relation between the first correction strain and the second correction strain and the transverse force and the longitudinal force respectively is firstly needed to be obtained, and then the transverse force and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested are calculated according to the corresponding relation and the obtained first wheel track correction strain and the obtained second wheel track correction strain.

Here, the fiber grating sensor is made using photosensitivity of an optical fiber. When the strain, temperature or other physical quantity of the environment where the fiber grating is located changes, the period of the grating or the refractive index of the fiber core changes, so that the wavelength of reflected light changes, and the change condition of the physical quantity to be measured can be obtained by measuring the change of the wavelength of reflected light before and after the change of the physical quantity.

The first fiber bragg grating sensor FBG1, the second fiber bragg grating sensor FBG2 and the third fiber bragg grating sensor FBG3 can induce the deformation of the fiber bragg grating sensor when the external force, the temperature and other loads are applied to the railway track to be tested, so that the strain change of the railway track to be tested is reflected. And in the calibration process, the external force load applied to the railway track to be measured is the transverse force and the longitudinal force applied to the railway track to be measured.

Referring to fig. 6, the embodiment of the present application further provides a specific method for obtaining the relations between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force, respectively. The method comprises the following steps:

s601: acquiring multiple groups of target measurement data acquired by a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor when different target transverse forces and different target longitudinal forces are respectively applied to a railway track to be tested; each set of target measurement data includes; first target measurement data, second target measurement data, and third target measurement data;

s602: aiming at each group of target measurement data, acquiring a first target correction strain according to the first target measurement data and the second target measurement data; acquiring second target corrected strain according to the first target measurement data and the third target measurement data;

when a train acts on the midspan position of the railway track to be tested, the stress condition of the railway track to be tested is shown in fig. 7, the center of the midspan section of the railway track to be tested is taken as an origin O, the direction of transverse force application is taken as an x axis, the direction of longitudinal force application is taken as a longitudinal axis, and the extending direction of the railway track to be tested is taken as a z axis, so that a coordinate system is established; the distance from the origin O to the foot is c and the distance from the origin O to the head is h.

The positive stress along the axial direction of the railway track to be tested at any point (x, y) on the midspan section is formed by bending moment M in the x, y direction _x 、M _y The resulting bending stressAnd->Under the unbalanced load condition (the acting force point of the rail head of the railway rail to be tested is not in the middle of the rail head) torque T of the railway rail to be tested _Z The torsional positive stress produced->And additional stress under rail temperature change +.>Combined, the expression is (2):

(2)

because the FBG1 is near the center of the section of the railway track to be tested, the pasting error is not considered, and the positive stress at the FBG1 position is (3) under the assumption that the positive stress under the action of bending moment and torque is 0:

(3)

wherein F is _T The temperature force A is the temperature force of the railway track to be measured, and the section area A is the section area of the railway track to be measured. The FBG1 can be seen from the above to accurately test the axial additional temperature stress of the railway track to be tested under the temperature change.

On this basis, the strain of the railway track to be measured can be detected by the FBGs 2 and 3. Referring to the pasting positions of the fiber bragg grating sensors shown in fig. 1, the pasting positions are easily obtained by material mechanics, and the positive stresses at the positions of the FBG2 and the FBG3 are respectively (4):

(4)

wherein I is _x 、I _y The moments of inertia of the section of the railway track to be measured to the x-axis and the y-axis respectively,and->Torsional normal stresses at the rail foot upper corner and rail foot center, respectively, due to the eccentric forces. When the vertical force and the transverse force are eccentric to different degrees, the normal stress at the rail bottom part is less influenced by torsion, and only tiny torsion normal stress is generated, so that the rail bottom part can be ignored. In summary, the torsional positive stress effect is ignored and σ is subtracted from equation (4) ₁ To obtain the corrected stress sigma' ₂ Sigma'. ₃ As formula (5):

(5)

simultaneously dividing the Young's modulus E of the railway track to be measured by the formula (5) to obtain a first target correction strain and a second target correction strain, wherein the first target correction strain and the second target correction strain are as shown in the formula (6):

(6)

wherein ε ₁ 、ε ₂ 、ε ₃ The strain values obtained by direct monitoring of the sensors FBG1, FBG2, FBG3, respectively, i.e. the first, second and third target measurement data. The bending moment at the mid-span position of the single-span rail can be obtained by a simple beam bending moment calculation formula and is (7):

(7)

bringing the above formula (7) into the formula (6) to obtain the formula (8)

(8)

Equation (8) is a calculation formula of the first target corrected strain and the second target corrected strain.

S603: and obtaining linear relations between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively according to the first target corrected strain and the second target corrected strain corresponding to all the target measurement data and the corresponding relation between the target transverse force and the target longitudinal force.

When the method is concretely realized, the formula (8) is arranged, and a linear relation formula between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively can be obtained, as shown in the formula (9).

(9)

Namely: formula (1)

Wherein: epsilon ₂ ' represents a first corrected strain; epsilon ₃ ' represents a second corrected strain; f (F) _v Representing a longitudinal force; f (F) _l Representing a lateral force; A. b, C are fitting parameters.

And (3) according to the linear relation formula (1), performing linear fitting on the first target corrected strain and the second target corrected strain corresponding to all the target measurement data, and the corresponding target transverse force and target longitudinal force to acquire the linear relation between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively.

The process of linearly fitting the first target corrected strain and the second target corrected strain corresponding to all the target measurement data, and the corresponding target transverse force and target longitudinal force to obtain the linear relationship between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively is the process of solving the A, B, C fitting parameters.

Referring to fig. 7, a third embodiment of the present application further provides a specific method for obtaining a linear relationship between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force respectively according to the first corrected strain and the second corrected strain corresponding to all the target measurement data and the corresponding relationship between the target lateral force and the target longitudinal force, where the first corrected strain and the second corrected strain correspond to the target lateral force and the target longitudinal force, respectively:

S701: applying different magnitudes of target transverse forces or target longitudinal forces to the railway track to be tested;

for example: applying a plurality of groups of target transverse forces or target longitudinal forces to the rail head by adopting a special steel wire rope fixing jack; and loads the multi-stage steps for each of the vertical and lateral forces, for example, loads the five-stage steps for each of the vertical and lateral forces (28.5 kN, 46.8kN, 63.0kN, 84.8kN, 95.9kN; 12.0kN, 25.3kN, 37.9kN, 50.7kN, 61.4kN in the lateral direction). A pressure sensor is arranged between the jack and the rail head, and the applied pressure can be measured.

S702: aiming at each time of applying a target transverse force or a target longitudinal force to a railway track to be tested, sampling by a first fiber bragg grating sensor according to a preset first sampling frequency, acquiring first data under sampling, and taking the average value of the first data as first target measurement data;

in the specific implementation, because the temperature when the sensor is pasted and the temperature when the sensor is actually calibrated have certain difference, in order to eliminate the influence of temperature force on the calibration result, and the temperature change is slower, the first sampling frequency can be set to be smaller, for example, the first sampling frequency of the FBG1 is set to be sampled every 10 minutes, the first data under sampling is obtained, and the average value of the first data is used as the first target measurement data.

S703: synchronously sampling according to a preset second sampling frequency through a second fiber grating sensor and a third fiber grating sensor to obtain second data and third data under multiple sampling;

in a specific implementation, to ensure as high accuracy as possible, the second sampling frequency is set to be larger, for example, the second sampling frequencies of the FBG2 and the FBG3 are set to be 1kHz, and the second data and the third data under multiple sampling are acquired.

S704: acquiring the average value of the second data under multiple sampling, and taking the average value of the second data under multiple sampling as second target measurement data;

s705: and acquiring the average value of the third data under the multiple sampling, and taking the average value of the third data under the multiple sampling as third target measurement data.

The embodiment of the application uses the fiber grating sensor as a main component for measurement; the fiber bragg grating sensor has the advantages of high detection sensitivity, high precision, long service life, long-term stability and the like, and the first fiber bragg grating sensor is respectively arranged on the rail web of the railway track to be detected; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested. When the measurement is carried out, first wheel track measurement data, second wheel track measurement data and third wheel track measurement data which are respectively acquired by a first fiber grating sensor, a second fiber grating sensor and a third fiber grating sensor when a train passes through a railway track to be measured are firstly acquired; then, according to the first, second and third wheel track measurement data, acquiring a first wheel track correction strain and a second wheel track correction strain; and calculating the transverse force and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first and second wheel track correction strains and the relation between the first and second correction strains and the transverse force and the longitudinal force respectively acquired in advance. By adopting the railway track wheel and rail force measuring method, the accuracy and the stability of track wheel and rail force monitoring can be improved, and the long-term dynamic monitoring of the wheel and rail force can be realized.

Based on the same inventive concept, the embodiment of the application also provides a railway track wheel rail force measuring device corresponding to the railway track wheel rail force measuring method, and because the principle of solving the problem of the device in the embodiment of the application is similar to that of the railway track wheel rail force measuring method in the embodiment of the application, the implementation of the device can be referred to the implementation of the method, and the repetition is omitted.

Referring to fig. 8, a fourth embodiment of the present application provides a rail force measuring apparatus for a railway rail wheel, including:

the device is applied to a railway track wheel rail force measuring device comprising a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor, wherein the first fiber bragg grating sensor is used for being installed at the rail web of a railway track to be measured; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested, and the device comprises:

the acquiring module 81 is configured to acquire first wheel track measurement data, second wheel track measurement data, and third wheel track measurement data, which are acquired by the first fiber bragg grating sensor, the second fiber bragg grating sensor, and the third fiber bragg grating sensor, respectively, when the train passes through the railway track to be tested;

A first calculation module 82, configured to obtain a first wheel-track-correction strain and a second wheel-track-correction strain according to the first wheel-track measurement data, the second wheel-track measurement data, and the third wheel-track measurement data;

the second calculating module 83 is configured to calculate a wheel track lateral force and a wheel track longitudinal force applied to the railway track to be tested when the train passes through the railway track to be tested according to the first wheel track correction strain and the second wheel track correction strain, and the pre-acquired relationships between the first correction strain and the second correction strain and the lateral force and the longitudinal force, respectively.

Optionally, the method further comprises: a linear relationship acquisition module 84;

the linear relationship obtaining module 84 is configured to obtain the linear relationship between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force, respectively, by:

Optionally, the linear relationship obtaining module 84 is specifically configured to obtain the linear relationship between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force respectively according to the first target corrected strain and the second target corrected strain corresponding to all target measurement data, and the corresponding relationship between the target lateral force magnitude and the target longitudinal force magnitude by:

Optionally, the linear relation formula between the first corrected strain and the second corrected strain and the lateral force and the longitudinal force respectively satisfies the following formula (1):

(1)

Optionally, the linear relationship obtaining module 84 is specifically configured to obtain multiple sets of target measurement data obtained when the first fiber grating sensor, the second fiber grating sensor, and the third fiber grating sensor apply different amounts of target lateral force and different amounts of target longitudinal force to the railway track to be tested respectively by:

Corresponding to the method for measuring the rail force of the railway track wheel in fig. 5, a fifth embodiment of the present application further provides a computer device, as shown in fig. 9, which includes a memory 1000, a processor 2000, and a computer program stored in the memory 1000 and capable of running on the processor 2000, wherein the steps of the method for measuring the rail force of the railway track wheel are implemented when the processor 2000 executes the computer program.

Specifically, the above memory 1000 and the processor 2000 can be general-purpose memories and processors, which are not limited herein, and when the processor 2000 runs a computer program stored in the memory 1000, the above method for measuring rail force of railway rail track can be executed, so as to solve the problems of higher cost caused by adopting a vehicle-mounted test method and poor stability and reliability caused by adopting a resistance sensor method in the existing wheel rail force measuring technology, thereby improving the accuracy and stability of monitoring rail force of the rail track, and realizing long-term dynamic monitoring of the wheel rail force.

Embodiments of the present application provide a non-volatile computer storage medium having stored thereon computer executable instructions that are operable to perform the railway track wheel rail force measurement method of any of the method embodiments described above.

Specifically, the storage medium can be a general storage medium, such as a mobile magnetic disk, a hard disk and the like, and when a computer program on the storage medium is operated, the method for measuring the rail force of the railway rail wheel can be executed, so that the problems of higher cost caused by adopting a vehicle-mounted test method, poor stability and reliability caused by adopting a resistance sensor method and the like in the existing wheel rail force measuring technology are solved, the accuracy and stability of monitoring the rail force of the railway wheel are improved, and the long-term dynamic monitoring of the wheel rail force is realized.

The computer program product of the method and apparatus for measuring rail force of railway track wheel provided by the embodiments of the present application includes a computer readable storage medium storing program codes, and instructions included in the program codes may be used to execute the method in the foregoing method embodiment, and specific implementation may refer to the method embodiment and will not be described herein.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described system and apparatus may refer to corresponding procedures in the foregoing method embodiments, which are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. The device embodiments described above are merely illustrative.

Any particular values in all examples shown and described herein are to be construed as merely illustrative and not a limitation, and thus other examples of exemplary embodiments may have different values.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer readable storage medium executable by a processor. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Finally, it should be noted that: the above examples are only specific embodiments of the present application, and are not intended to limit the scope of the present application, but it should be understood by those skilled in the art that the present application is not limited thereto, and that the present application is described in detail with reference to the foregoing examples: any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or perform equivalent substitution of some of the technical features, while remaining within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. The rail force measuring method of the railway track wheel is characterized by being applied to a rail force measuring device of the railway track wheel, which comprises a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor, wherein the first fiber bragg grating sensor is used for being installed on the rail web of the railway track to be measured; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested, and the method comprises the following steps:

according to the first wheel track correction strain and the second wheel track correction strain and the linear relation between the first correction strain and the second correction strain, which are obtained in advance, and the transverse force and the longitudinal force respectively, calculating the wheel track transverse force and the wheel track longitudinal force applied to the railway track to be tested when the train passes through the railway track to be tested;

the linear relation between the first corrected strain and the second corrected strain and the transverse force and the longitudinal force respectively is obtained by the following method:

2. The method according to claim 1, wherein the obtaining the linear relationship between the first and second corrected strains and the lateral and longitudinal forces, respectively, according to the first and second target corrected strains and the corresponding relationship between the target lateral and longitudinal force magnitudes corresponding to all target measurement data, comprises:

3. The method according to claim 2, wherein the linear relation between the first and second corrected strains and the lateral and longitudinal forces, respectively, satisfies the following formula (1):

4. The method according to claim 1, wherein the acquiring the plurality of sets of target measurement data acquired when the first fiber bragg grating sensor, the second fiber bragg grating sensor, and the third fiber bragg grating sensor apply different magnitudes of target lateral force and different magnitudes of target longitudinal force to the railway track under test, respectively, specifically comprises:

5. The railway track wheel rail force measuring device is characterized by being applied to a railway track wheel rail force measuring device comprising a first fiber bragg grating sensor, a second fiber bragg grating sensor and a third fiber bragg grating sensor, wherein the first fiber bragg grating sensor is used for being installed on a rail web of a railway track to be measured; the second fiber bragg grating sensor is arranged at the upper corner of the rail bottom of the railway track to be tested; the third fiber bragg grating sensor is used for being installed at the center of the rail bottom of the railway rail to be tested, and the device comprises:

The second calculation module is used for calculating the transverse force of the wheel track and the longitudinal force of the wheel track applied to the railway track to be tested when the train passes through the railway track to be tested according to the first wheel track correction strain and the second wheel track correction strain and the relations between the first correction strain and the second correction strain, which are acquired in advance, and the transverse force and the longitudinal force respectively;

further comprises: a linear relation acquisition module;

6. The device according to claim 5, wherein the linear relation obtaining module is specifically configured to obtain the linear relation between the first corrected strain, the second corrected strain and the lateral force and the longitudinal force according to the first target corrected strain, the second target corrected strain and the corresponding relation between the target lateral force magnitude and the target longitudinal force magnitude, respectively, corresponding to all target measurement data by:

7. The apparatus of claim 6, wherein the linear relationship between the first and second corrected strains and the lateral and longitudinal forces, respectively, satisfies the following equation (1):

(1)

8. The device according to claim 5, wherein the linear relation obtaining module is specifically configured to obtain the plurality of sets of target measurement data obtained when the first fiber bragg grating sensor, the second fiber bragg grating sensor, and the third fiber bragg grating sensor apply different amounts of target lateral force and different amounts of target longitudinal force to the railway track to be measured respectively by: