CN117782397A - Switch machine stress monitoring system and method - Google Patents

Abstract

The invention provides a system and a method for monitoring stress of a point machine, comprising the following steps: the clamp is arranged on the switch machine action connecting rod and is tightly attached to the switch machine action connecting rod; the clamp conducts stress borne by the switch machine action connecting rod to a plurality of strain gauges arranged on the clamp, so that each strain gauge outputs a corresponding weak voltage signal through a bridge type simulation module, and the acquisition module outputs a voltage signal corresponding to each weak voltage signal; the upper computer monitors stress of the switch machine based on the strain quantity corresponding to each voltage signal; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force. According to the system, the plurality of strain gages are deployed on the clamp tightly attached to the action connecting rod of the point switch, so that the switching force and the close stress of the point switch can be detected, meanwhile, the crawling force and the upwarp force can be detected, more point switch stress data can be obtained compared with the prior art, and the visual and comprehensive monitoring of the mechanical performance of the point switch under the dynamic and static working conditions can be realized.

Description

Switch machine stress monitoring system and method

Technical Field

The invention relates to the technical field of stress monitoring of a switch machine, in particular to a system and a method for monitoring stress of the switch machine.

Background

Conventional monitoring of working conditions of a switch machine generally monitors a current curve of the working condition of the switch machine through a centralized monitoring system, so as to indirectly reflect the mechanical performance of the switch machine through monitoring of electrical parameters. The lack of direct monitoring on stress conditions of the switch machine, the stress monitoring method mainly relies on manual checking of the close contact degree and the action conditions of the switch machine in the pulling process to judge indirectly, a great deal of manpower and time are required, and the accuracy and reliability are not high. At present, common stress monitoring means only monitor the resistance change and the close contact force change in the switching process of the point switch, and lack monitoring means for the creep force and the upwarp force of the point switch action connecting rod caused by the close contact force, point rail creep and upwarp under static state, so that the visual and comprehensive monitoring of the mechanical performance of the point switch under dynamic and static working conditions cannot be realized; in addition, at present, no good solution means exists for the problems of zero drift and temperature drift of the stress acquisition equipment of the switch machine, so that the accuracy and reliability of stress monitoring data are poor.

Disclosure of Invention

The invention aims to provide a system and a method for monitoring the stress of a point switch so as to acquire more stress data of the point switch and realize visual and comprehensive monitoring of mechanical properties of the point switch under dynamic and static working conditions.

The invention provides a stress monitoring system of a point machine, which comprises: the switch machine stress data acquisition device and the upper computer are in communication connection with each other; the switch stress data acquisition device includes: the sensing module, the acquisition module and the transmission module are connected in sequence; the sensing module includes: a clamp, and a plurality of strain gauges mounted on the clamp; the clamp is arranged on the action connecting rod of the switch machine; the clamp is tightly attached to the action connecting rod of the switch machine;

the clamp is used for respectively transmitting stress borne by the switch machine action connecting rod to each strain gauge so that each strain gauge outputs a corresponding weak voltage signal through the bridge type simulation module;

the acquisition module is used for acquiring each weak voltage signal and outputting a voltage signal corresponding to each weak voltage signal respectively;

the transmission module is used for transmitting the strain quantity corresponding to each voltage signal to the upper computer;

the upper computer is used for monitoring the stress of the switch machine based on each strain; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force.

Further, the plurality of strain gages includes: a first strain gage, a second strain gage, a third strain gage, and a fourth strain gage; the clamp comprises a first symmetrical structural member and a second symmetrical structural member; openings matched with the shapes of the action connecting rods are formed in the inner sides of the first symmetrical structural member and the second symmetrical structural member and are used for being tightly attached to the action connecting rods;

The first symmetrical structure includes: the first connecting bridge, the second connecting bridge and two symmetrical first U-shaped structures; the two first U-shaped structures are connected through a first connecting bridge and a second connecting bridge;

the second symmetrical structure includes: the third connecting bridge, the fourth connecting bridge and two symmetrical second U-shaped structures; the two second U-shaped structures are connected through a third connecting bridge and a fourth connecting bridge;

the first connecting bridge is attached to the upper surface of the action connecting rod, the second connecting bridge is attached to the left surface of the action connecting rod, the third connecting bridge is attached to the lower surface of the action connecting rod, and the fourth connecting bridge is attached to the right surface of the action connecting rod;

the first strain gauge is attached to the first connecting bridge, the second strain gauge is attached to the second connecting bridge, the third strain gauge is attached to the third connecting bridge, and the fourth strain gauge is attached to the fourth connecting bridge.

Further, the acquisition module includes: the amplifying and filtering module and the ADC conversion module are connected in sequence;

the amplifying and filtering module is used for amplifying and filtering each weak voltage signal to obtain voltage processing signals corresponding to each weak voltage signal respectively;

and the ADC conversion module is used for carrying out analog-to-digital conversion processing on each voltage processing signal to obtain voltage signals corresponding to each voltage processing signal respectively.

Further, the monitoring system also comprises a processing module; the acquisition module is connected with the transmission module through the processing module;

the processing module is used for receiving each voltage signal acquired by the acquisition module, converting each voltage signal into a corresponding strain quantity, and calculating based on a pre-integrated zero drift suppression mathematical model to obtain a strain quantity check value corresponding to each strain quantity respectively; the null shift suppression mathematical model is obtained by:

when the action connecting rod is not stressed, a first offset and a second offset of each strain are obtained through a preset first calibration method and a preset second calibration method;

a null shift suppression mathematical model is determined based on the first offset and the second offset.

Further, the switch machine stress data acquisition device also comprises a power module for supplying power to the sensing module, the acquisition module, the transmission module and the processing module.

Further, the switch machine stress data acquisition device also comprises a temperature sensor module for acquiring environmental temperature information.

Further, the switch machine stress data acquisition device further comprises a vibration sensor module, wherein the vibration sensor module is used for receiving a vibration signal from the action connecting rod so as to control the switch machine stress data acquisition device to start working according to the vibration signal.

Further, the transmission module is used for transmitting each strain check value and temperature information to the upper computer;

the upper computer calculates each strain check value and temperature information according to a preset temperature drift suppression mathematical model to obtain a first stress, a second stress, a third stress and a fourth stress;

the mathematical model of temperature drift inhibition is obtained by the following steps:

acquiring a first-order linear function between a strain check value obtained by a processing module and the ambient temperature based on a preset reference temperature and a preset first linear proportionality coefficient;

acquiring a second first-order linear function between the first linear scaling factor and the stress born by the strain gauge based on a preset reference coefficient and a preset second linear scaling factor;

substituting the second first-order linear function into the first-order linear function to obtain the temperature drift suppression mathematical model.

Further, the upper computer includes: the first analysis module is used for analyzing the first stress and the third stress to obtain conversion force, adhesion force and upwarp force; the second analysis module is used for analyzing the second stress and the fourth stress to obtain crawling force.

The invention provides a method for monitoring stress of a point machine, which comprises the following steps:

The clamp conducts stress borne by the switch machine action connecting rod to each strain gauge respectively, so that each strain gauge outputs a corresponding weak voltage signal through the bridge type simulation module;

the acquisition module acquires each weak voltage signal and outputs a voltage signal corresponding to each weak voltage signal respectively;

the transmission module transmits the strain quantity corresponding to each voltage signal to the upper computer;

the upper computer monitors the stress of the switch machine based on each strain; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force.

The invention provides a system and a method for monitoring stress of a point machine, comprising the following steps: the clamp is arranged on the switch machine action connecting rod and is tightly attached to the switch machine action connecting rod; the clamp conducts stress borne by the switch machine action connecting rod to a plurality of strain gauges arranged on the clamp, so that each strain gauge outputs a corresponding weak voltage signal through a bridge type simulation module, and the acquisition module outputs a voltage signal corresponding to each weak voltage signal; the upper computer monitors stress of the switch machine based on the strain quantity corresponding to each voltage signal; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force. According to the system, the plurality of strain gages are deployed on the clamp tightly attached to the action connecting rod of the point switch, so that the switching force and the close stress of the point switch can be detected, meanwhile, the crawling force and the upwarp force can be detected, more point switch stress data can be obtained compared with the prior art, and the visual and comprehensive monitoring of the mechanical performance of the point switch under the dynamic and static working conditions can be realized.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a stress monitoring system for a switch machine according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another stress monitoring system for a switch machine according to an embodiment of the present invention;

FIG. 3 is a schematic side view of a clip according to an embodiment of the present invention;

fig. 4 is a schematic front view of a clip according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of another system for monitoring stress in a switch machine according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of another system for monitoring stress in a switch machine according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of another embodiment of a system for monitoring stress in a switch machine;

FIG. 8 is a schematic diagram of another embodiment of a system for monitoring stress in a switch machine;

FIG. 9 is a schematic diagram showing a linear fit relationship between strain gage values and temperature under different external stress conditions according to an embodiment of the present invention;

FIG. 10 is a schematic diagram of a linear fit relationship between an external force and a first linear scaling factor according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of another exemplary switch stress monitoring system according to the present disclosure;

fig. 12 is a flowchart of a method for monitoring stress of a switch machine according to an embodiment of the present invention.

Icon:

1-a stress data acquisition device of the switch machine; 11-a sensing module; 111-clamping; 1111—a first symmetrical structure; 11111—a first connection bridge; 11112-a second connecting bridge; 11113-a first U-shaped structure; 1112-a second symmetrical structure; 11121-a third connecting bridge; 11122-a fourth connecting bridge; 11123-second U-shaped structure; 112-strain gage; 1121-a first strain gauge; 1122-second strain gage; 1123-third strain gage; 1124-fourth strain gage; 12-an acquisition module; 121-a bridge analog module; 122-an amplifying and filtering module; a 123-ADC conversion module; 13-a transmission module; 14-a processing module; 15-a power module; 16-a vibration sensor module; 17-a temperature sensor module; 2-an upper computer; 21-a first analysis module; 22-a second analysis module.

Detailed Description

The technical solutions of the present invention will be clearly and completely described in connection with the embodiments, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

A switch machine is a device for controlling the position of a switch and changing the running direction of a train, and needs to output enough switching force during the switching process of the switch to ensure that the switch is switched into place. After the switch is switched, the switch rail is kept in a locked state, so that the switch rail is in a definite state, and the working reliability of the switch machine directly influences the running safety of the train. Stress monitoring is therefore important to ensure proper operation and safety of the switch machine. The switch machine is used as an important component of rail transit equipment and is widely applied to various urban public transportation systems such as subways, urban rail transit, trams and the like. The running of the switch machine needs to bear the weight and the inertia force of a train, and the internal structure of the switch machine is complex and consists of a plurality of parts, so that the problems of stress concentration, fatigue damage and the like are easy to occur, and the severity of the problems can directly influence the running safety and the service life of the switch machine. The switch machine is used as outdoor signal equipment and is in a harsh outdoor working environment for a long time, various foreign matters such as car passing vibration, stones, coal cinder, ice cubes and the like are easy to influence the operating machinery, the circuit and the like, and an outdoor monitoring means is needed for effectively monitoring the various elements influencing the normal operation of the switch machine.

Therefore, it is necessary to monitor the stress of the switch machine, and the stress of the switch machine is used as an outdoor monitoring means to directly detect various weak influences of the various elements on the mechanical properties of the switch machine. By monitoring the stress distribution conditions of the switch machine in different directions, the fatigue damage problem of the internal structure of the switch machine can be found early, measures can be taken in time, and the normal operation and safety of the switch machine are ensured. In addition, the stress monitoring of the switch machine can also evaluate the load capacity and durability of the switch machine, and provide valuable data support for maintaining and repairing the switch machine. The conventional working condition monitoring of the switch machine is to monitor the working current curve of the switch machine through a centralized monitoring system, so as to indirectly reflect the mechanical performance of the switch machine through monitoring the electric parameters, and lack of direct monitoring on the stress condition of the switch machine, the stress monitoring method mainly relies on manual checking of the close contact degree and the working condition of the switch machine in the pulling process to indirectly judge, and the methods require a great deal of manpower and time and have low accuracy and reliability.

For the sake of understanding the present embodiment, a switch machine stress monitoring system disclosed in the present embodiment will be described in detail.

The invention provides a point machine stress monitoring system, as shown in figure 1, which comprises a point machine stress data acquisition device 1 and an upper computer 2 which are in communication connection with each other; the point machine stress data acquisition device 1 comprises: the sensing module 11, the acquisition module 12 and the transmission module 13 are sequentially connected; the sensor module 11 includes: a clip 111, and a plurality of strain gauges 112 mounted on the clip 111; the clamp 111 is mounted on the switch machine action connecting rod; the clamp 111 is tightly attached to the action connecting rod of the switch machine;

the clamp 111 is configured to respectively transmit stress applied to the switch machine action connecting rod to each strain gauge 112, so that each strain gauge 112 outputs a corresponding weak voltage signal through the bridge analog module 121;

the acquisition module 12 is configured to acquire each weak voltage signal and output a voltage signal corresponding to each weak voltage signal;

the transmission module 13 is used for transmitting the strain quantity corresponding to each voltage signal to the upper computer 2;

the upper computer 2 is used for monitoring the stress of the switch machine based on each strain amount; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force.

In actual implementation, the switch machine stress data acquisition device 1 is mounted on a switch machine action connecting rod, and the switch machine action connecting rod can be a round action connecting rod or a square action connecting rod; in general, for an electric switch machine with an inner locking switch, the action connecting rod is a round rod, and for an electric switch machine with an outer locking switch, the action connecting rod is a square rod.

The switch stress data acquisition device 1 generally comprises three parts, namely a sensor part, an analog front end, a data transmission part and a power supply part. The sensor part (corresponding to the above sensing module) mainly comprises an annular clamp and a plurality of strain gauges on the annular clamp, the clamp 111 is made of the same material (such as steel) as the action connecting rod of the switch machine, the same temperature characteristic as the action connecting rod can be guaranteed, and the number of the strain gauges on the annular clamp is generally 4.

Specifically, the clip 111 may be wrapped around the switch machine action bar in an asymmetric wrapping manner, so that the clip 111 is tightly attached to the switch machine action bar. 4 strain gages are symmetrically arranged on the 4 connecting bridges of the clamp 111 in the up-down, left-right direction, so that the clamp 111 realizes 4-path stress data (corresponding to the component force of the stress in the up-down, left-right direction) transmission.

For the electric switch machine of the internal locking turnout, the action connecting rod is generally a round rod piece with the outer diameter of 36mm, and a clamp with a semicircular groove on the inner side can be used. For the external locking turnout (mainly by electrohydraulic), the action connecting rod is a square rod piece, and a clamp with a rectangular square groove formed on the inner side can be used. Both types of clamps have four-way stress conduction data.

A general method for distinguishing the positions of the strain gages of the yoke 111 is to face the switch machine by a person and distinguish the positions of the strain gages in a vertical and horizontal direction by a person.

The analog front end and the data transmission part are equivalent to the bridge analog module 121, the acquisition module 12 and the transmission module 13, wherein the acquisition module 12 comprises an amplifying and filtering module 122 and an ADC conversion module 123 which are connected in sequence;

the strain gauge 112 is electrically connected to the bridge analog module 121, and when the lever of the rotary measuring machine is stressed, the strain gauge deforms, so that the resistance of the strain gauge 112 changes, and the bridge analog module 121 converts the force signal into a weak voltage signal (equivalent to converting the resistance change corresponding to the deformation of the strain gauge 112 into a weak voltage signal).

The amplifying and filtering module is used for amplifying and filtering each weak voltage signal to obtain voltage processing signals corresponding to each weak voltage signal respectively; and the ADC conversion module is used for carrying out analog-to-digital conversion processing on each voltage processing signal to obtain voltage signals corresponding to each voltage processing signal respectively.

The bridge analog module 121 is a strain sensor acquisition circuit, and may be a bridge circuit or a constant current source circuit, the amplifying and filtering module is a signal conditioning circuit, and may be an amplifying circuit and a filtering circuit, and the ADC conversion module is an ADC conversion circuit, and may be a 24-bit high-precision ADC chip with a system calibration function.

The transmission module 13 may receive the data collected by the ADC chip through the SPI bus, and transmit the data to an application system (upper computer) through a wired or wireless interface.

The battery part (equivalent to a power module) is composed of 6 high-energy lithium batteries, and the whole acquisition device is powered by adopting a two-string three-parallel mode.

In practice, the bridge analog module 121, the acquisition module 12 and the transmission module 13 are generally integrated on a circuit board, the circuit board is connected to the clamp 111, and specifically, the circuit board and the clamp 111 can be fastened together by using 4 fixing bolts, and the power module 15 can be connected to the circuit board to supply power to each module on the circuit board.

In a specific implementation process, after the power lever of the transfer and measurement machine is stressed, force can be conducted to each strain gauge through the clamp 111, each strain gauge deforms, the resistance of the strain gauge can change after deformation, then the resistance change corresponding to deformation is converted into a weak voltage signal through the bridge analog module (in practice, 4 bridge circuits can be adopted by the bridge analog module, each bridge circuit can be correspondingly connected with one strain gauge, the resistance change corresponding to the strain gauge is converted into a weak voltage signal), as weak voltage signals are output, the weak voltage signals can be amplified and filtered through the amplifying circuit and the filter circuit (4 amplifying circuits and the filter circuit can be correspondingly connected with one bridge circuit), so as to obtain voltage processing signals, and therefore ADC chips (4 ADC chips can be adopted, each ADC chip is correspondingly connected with one amplifying circuit and the filter circuit) can be used for acquiring the voltage signals, the corresponding voltage signal can be transmitted to the strain gauge corresponding to the strain gauge through the communication unit (namely, the strain gauge can be correspondingly arranged on the machine, and the strain gauge can be correspondingly set to the voltage signal corresponding to the strain gauge, namely, the strain gauge can be correspondingly processed according to the actual strain gauge value.

Stress conditions corresponding to each strain amount are obtained through a preset corresponding relation between the strain amounts and the force, stress conditions corresponding to each strain amount (namely basic forces in 4 directions) are analyzed through comparison, stress monitoring such as conversion force, close adhesion force, crawling force, upwarp force and the like can be achieved through combination or cancellation among the 4 basic forces, specifically, change conditions of the conversion force, close adhesion force and upwarp force can be analyzed through comparison of strain amounts corresponding to upper and lower strain sensors (strain sheets), whether conversion and close adhesion abnormality and upwarp of a switch rod member exist can be judged, change conditions of crawling force can be analyzed through comparison of strain amounts corresponding to left and right strain sensors, whether crawling and crawling directions exist on a switch point rail can be judged, and a technical means is provided for more accurately judging fault reasons and accurately early warning of the switch machine.

The switch stress monitoring system comprises: comprising the following steps: the clamp is arranged on the switch machine action connecting rod and is tightly attached to the switch machine action connecting rod; the clamp conducts stress borne by the switch machine action connecting rod to a plurality of strain gauges arranged on the clamp, so that each strain gauge outputs a corresponding weak voltage signal through a bridge type simulation module, and the acquisition module outputs a voltage signal corresponding to each weak voltage signal; the upper computer monitors stress of the switch machine based on the strain quantity corresponding to each voltage signal; wherein the stress comprises: the system of conversion force, close adhesion force, crawling force and upwarp force can realize detection of conversion force and close adhesion force in the conversion stage of the switch machine by arranging a plurality of strain gauges on the clamp tightly attached to the action connecting rod of the switch machine, and can realize detection of static close adhesion force, crawling force and upwarp force.

Based on the above-mentioned switch stress monitoring system, another switch stress monitoring system is provided in an embodiment of the present invention, as shown in fig. 2, the plurality of strain gauges 112 include: a first strain gage 1121, a second strain gage 1122, a third strain gage 1123, and a fourth strain gage 1124; the clip 111 includes a first symmetrical structure 1111 and a second symmetrical structure 1112; openings matched with the shape of the action connecting rod are formed in the inner sides of the first symmetrical structural member 1111 and the second symmetrical structural member 1112 and are used for being tightly attached to the action connecting rod;

the first symmetrical structure 1111 includes: a first connection bridge 11111, a second connection bridge 11112, and two symmetrical first U-shaped structures 11113; wherein the two first U-shaped structures 11113 are connected by a first connecting bridge 11111 and a second connecting bridge 11112;

the second symmetrical structure 1112 includes: third connection bridge 11121, fourth connection bridge 11122, and two symmetrical second U-shaped structures 11123; wherein the two second U-shaped structures 11123 are connected by a third connecting bridge 11121 and a fourth connecting bridge 11122;

the first connecting bridge 11111 is attached to the upper surface of the action connecting rod, the second connecting bridge 11112 is attached to the left surface of the action connecting rod, the third connecting bridge 11121 is attached to the lower surface of the action connecting rod, and the fourth connecting bridge 11122 is attached to the right surface of the action connecting rod;

The first strain gage 1121 is bonded to the first connecting bridge 11111, the second strain gage 1122 is bonded to the second connecting bridge 11112, the third strain gage 1123 is bonded to the third connecting bridge 11121, and the fourth strain gage 1124 is bonded to the fourth connecting bridge 11122.

In order to facilitate the installation of the clamp on the action connecting rod, the clamp 111 is designed into two approximately symmetrical structural members, namely a first symmetrical structural member 1111 and a second symmetrical structural member 1112, semicircular holes or square openings corresponding to the shapes of the action connecting rods are formed on the inner sides of the two symmetrical structural members, and the circular action connecting rods for adapting the inner locking turnout and the square action connecting rods for externally locking the turnout can be specifically seen from a side structural schematic diagram of the clamp shown in fig. 3; the inner openings of the first symmetrical structural member 1111 and the second symmetrical structural member 1112 in fig. 3 are exemplified by semi-circles; the left end and the right end of each symmetrical structural member are U-shaped structures, the middle parts of the symmetrical structural members are connected through two connecting bridges, and strain gauges are attached to the plane positions of the connecting bridges. Each U-shaped structure is provided with 4 screw holes, during actual installation, 4 fixing bolts can penetrate through the 4 screw holes at the extreme edge of each symmetrical structural member so as to fasten two symmetrical structural members and an action connecting rod together, and other 4 fixing bolts penetrate through the 4 screw holes of the circuit board and the remaining 4 screw holes of one symmetrical structural member so as to fasten the clamp 111 and the circuit board together, and particularly, the schematic diagram of the front structure of the clamp shown in fig. 4 can be seen; fig. 4 (a) is a schematic front view of the first symmetrical structure 1111, and fig. 4 (b) is a schematic front view of the second symmetrical structure 1112.

Still see the side structure schematic diagram of a clamp as shown in fig. 3, in order to guarantee clamp 111 and action connecting rod closely to laminate, adopt the asymmetric mode of encircling, at action connecting rod upper surface, paste the contact surface of two symmetrical structure members completely tightly, and at action connecting rod's lower surface, reserve the space of 2mm between the contact surface of two symmetrical structure members after tightening 4 bolts, this kind of mode's advantage is can ensure that clamp 111 can with action connecting rod tight fit, reduce the loss of meeting an emergency in the conduction process, also make action connecting rod all can fasten in its tolerance range simultaneously. Specifically, the upper surfaces of the inner sides of the two first U-shaped structures are in direct contact with the upper surfaces of the inner sides of the two second U-shaped structures, and a gap of 2mm exists between the lower surfaces of the inner sides of the two first U-shaped structures and the lower surfaces of the inner sides of the two second U-shaped structures.

On the basis of the switch machine stress monitoring system, the embodiment of the invention also provides another switch machine stress monitoring system, as shown in fig. 5, wherein the monitoring system also comprises a processing module 14; the acquisition module 12 is connected with the transmission module 13 through the processing module 14;

the processing module 14 is configured to receive each voltage signal acquired by the acquisition module 12, convert each voltage signal into a corresponding strain, and calculate the corresponding strain based on a pre-integrated null shift suppression mathematical model to obtain a strain check value corresponding to each strain; the null shift suppression mathematical model is obtained by:

When the action connecting rod is not stressed, a first offset and a second offset of each voltage signal are obtained through a preset first calibration method and a preset second calibration method;

a null shift suppression mathematical model is determined based on the first offset and the second offset.

The processing module 14 may adopt an MCU, and in actual implementation, the MCU may receive the strain sensor data (i.e. voltage signal) collected by the collecting module 12 through an SPI interface, and after performing verification processing on the data, the data is transmitted to the transmitting module 13 through a serial port.

Specifically, the data can be checked by obtaining a null shift inhibition mathematical model in advance. The zero drift inhibition mathematical model is as follows: strain gauge = voltage signal-first offset-second offset; the first offset and the second offset in the mathematical formula are fixed values obtained after initial zeroing operation is performed on the stress data acquisition device of the switch machine when the turnout is in a quarter state, namely the action connecting rod is in an unstressed state.

In practice, according to the characteristic of resistance change of the strain gauge after being stressed, the initial value output by the strain gauge under the condition of no load (no stress) is ideally zero, but in practical application, the switch stress data acquisition device has a non-zero output value under the condition of no applied force, namely zero drift, due to the influence of factors such as inherent differences of components in the strain sensor, inherent errors of analog front-end circuit components (such as bridge circuit resistance mismatch, constant current source precision, ADC reference power supply fluctuation and the like). Without tuning, the measured value of stress would be affected by zero drift, resulting in inaccurate measurement results.

Therefore, in order to ensure the accuracy and reliability of the acquisition result, the initial zeroing of the point machine stress data acquisition device is required. Since zero drift is an inevitable characteristic inherent to the device, and this amount of drift is typically linear, it only affects the upward or downward shift of the zero. And when different stress sensors are initially connected, the stress data acquisition device of the switch machine actively adjusts the initial zero value. In this embodiment, the method for performing initial zeroing on the switch machine stress data acquisition device in the unstressed state of the switch machine action connecting rod may include coarse ADC adjustment (corresponding to the first calibration method) and fine software adjustment (corresponding to the second calibration method), that is, precise zeroing of the acquisition device is achieved by combining coarse ADC adjustment and fine software adjustment. Specifically, besides the high-precision and low-temperature drift characteristic device (such as a 24-bit high-precision ADC chip with a system calibration function), the zero drift suppression can be realized by combining a software algorithm.

The first calibration method is as follows: it can be understood that the ADC has the existing system zero level calibration method; in actual implementation, after the first zeroing is implemented by the above-mentioned first calibration method, if the acquired value (the check value obtained after the strain amount is calibrated by the first calibration method) received by the processing module 14 still has a gap from the real zero point. On a sub-basis, the zeroing can be continuously performed by a second calibration method, that is, a software algorithm integrated in an MCU (processing module), specifically, the MCU can judge whether fine adjustment is required according to the obtained check value, and if necessary, the second calibration method can be performed, where the second calibration method includes: the continuous receiving collection module 12 collects 100 voltage signals after the collection is stable (the stability can be judged by using a sliding window method), after converting the 100 voltage signals into corresponding 100 strain amounts, removing abnormal values (such as values with larger difference compared with zero) by normalization, taking the average value of the rest results to obtain a first offset, subtracting the offset from the subsequent collection value, and then using the offset; further, after determining the first offset, multiple sets of data continuously acquired by the acquisition module 12 may be received, where each set of data may include 40 voltage signals, for each set, a mean value of the first 20 acquired values (first mean value) and a mean value of the second 20 acquired values (second mean value) are calculated separately, then a difference between the first mean value and the second mean value is calculated to obtain a corresponding difference result of each set, if there are multiple continuously obtained target difference results smaller than a preset threshold value in the multiple difference results, the target difference result may be determined as the second offset (micro-variation of the current whole unstressed stage), and if there are not multiple continuously obtained target difference results smaller than the preset threshold value in the multiple difference results, the steps of receiving multiple sets of data continuously acquired by the acquisition module 12 may be repeatedly performed until the target difference result is obtained. When the voltage signal is acquired by the acquisition module 12 in a stressed state, calculation can be performed through a zero drift suppression mathematical model of the processing module 14, and a value obtained by subtracting the first offset and the second offset from the strain corresponding to the voltage signal is determined as a strain verification value corresponding to the strain.

It should be noted that, the first offset and the second offset corresponding to the voltage signal output by the same strain gauge are the same, and the first offset and the second offset corresponding to the voltage signal output by different strain gauges are not necessarily the same, and in actual implementation, the corresponding first offset and second offset can be determined by the above method for each strain gauge; and the zero drift suppression mathematical model corresponding to each strain gauge is determined, and the corresponding zero drift suppression mathematical model can be utilized to calculate according to the strain gauges corresponding to the acquired data, so as to obtain a strain quantity check value.

On the basis of the switch stress monitoring system, the embodiment of the invention also provides another switch stress monitoring system, as shown in fig. 6, the switch stress data acquisition device 1 further comprises a power module 15 for supplying power to the sensing module 11, the acquisition module 12, the transmission module 13 and the processing module 14.

On the basis of the above-mentioned switch stress monitoring system, the embodiment of the invention also provides another switch stress monitoring system, as shown in fig. 7, the switch stress data acquisition device 1 further comprises a vibration sensor module 16 for receiving a vibration signal from the action connecting rod, so as to control the switch stress data acquisition device 1 to start working according to the vibration signal.

In actual implementation, the vibration sensor module 16 is connected to the processing module 14, and when the switch machine is moved, a vibration signal can be detected to wake up the collection device by dormancy.

On the basis of the stress monitoring system of the switch machine, the embodiment of the invention also provides another stress monitoring system of the switch machine, as shown in fig. 8, the stress data acquisition device 1 of the switch machine also comprises a temperature sensor module 17 for acquiring environmental temperature information;

the mathematical model of temperature drift inhibition is obtained by the following steps:

acquiring a first-order linear function between the voltage check signal obtained by the processing module 14 and the ambient temperature based on a preset reference temperature and a preset first linear scaling factor;

acquiring a second first-order linear function between the first linear scaling factor and the stress born by the strain gauge based on a preset reference coefficient and a preset second linear scaling factor;

substituting the second first-order linear function into the first-order linear function to obtain the temperature drift suppression mathematical model.

In actual implementation, the transmission module 13 may transmit each strain calibration value and temperature information to the upper computer 2 as input parameters of a temperature drift compensation algorithm (temperature drift suppression mathematical model), and then the upper computer 2 performs temperature drift processing on each strain calibration value and temperature information according to a preset temperature drift suppression mathematical model to obtain a first stress, a second stress, a third stress, and a fourth stress.

The first-order linear function is: strain gauge check value = first linear scaling factor (ambient temperature-reference temperature);

the second first order linear function is: first linear scaling factor = second linear scaling factor x stress experienced by the strain gauge + reference factor;

the temperature drift inhibition mathematical model is as follows: strain gauge check value = (second linear scaling factor. Strain gauge stress + reference factor) (ambient temperature-reference temperature);

the second linear proportionality coefficient in the temperature drift suppression mathematical model is a fixed value obtained by a pre-test.

In practice, the strain gauge may cause a temperature drift phenomenon due to temperature influence, that is, even if the strain gauge is not subjected to stress change, the strain gauge monitoring value (that is, strain gauge verification value corresponding to an electrical signal output by the strain gauge) may also change due to the influence of the external environment temperature. Therefore, the temperature drift can cause a larger error in the measured stress. In order to eliminate the influence of temperature drift on the strain gauge monitoring value, a physical mathematical model is established for the parameter relation between the strain gauge monitoring value, the ambient temperature and the external stress so as to distinguish the influence of the temperature and the stress on the strain gauge monitoring value. Specifically, parameter changes can be performed on two conditions of temperature and stress, and the parameter relation between the strain quantity value of the strain gauge and two external parameters of temperature and stress is confirmed.

The specific modes of the test include:

obtaining strain quantity verification values corresponding to electric signals output by the strain gauge under different stress and different temperatures;

based on each stress, each temperature and each strain calibration value, a first linear proportionality coefficient between the temperature corresponding to each stress and the strain calibration value is obtained;

specifically, a high-low temperature test is carried out on the strain gauge under the same external stress condition, and the obtained strain gauge value (namely a strain gauge strain quantity monitoring value which can be practically expressed by voltage) is obtained; the strain gauge numerical value and the temperature change show a first-order linear relation, and a linear fitting relation (namely a first linear proportionality coefficient) between the strain gauge numerical value (namely strain gauge voltage reading) and the temperature under the same stress condition can be obtained through first-order linear fitting calculation; by presetting a plurality of external stress conditions, obtaining a linear fitting relation between the value of the strain gauge and the temperature under each external stress condition, and specifically referring to a schematic diagram of the linear fitting relation between the value of the strain gauge and the temperature under different external stress conditions as shown in fig. 9; in fig. 9, the abscissa indicates temperature and the ordinate indicates strain gauge value.

And determining a second linear proportionality coefficient between the first linear proportionality coefficient and the external stress according to the first linear proportionality coefficient between the temperature corresponding to each stress and the strain check value.

Specifically, the first-order fitting coefficient (first linear scaling coefficient) obtained by the high-low temperature test and the stress change show an approximate first-order linear relationship, and the linear fitting relationship between the first linear scaling coefficient and the stress (i.e., the second linear scaling coefficient) can be obtained through first-order linear fitting calculation, and specifically, reference may be made to a schematic diagram of a linear fitting relationship between an external stress and the first linear scaling coefficient as shown in fig. 10; wherein, the abscissa in fig. 10 is the force magnitude, and the ordinate is the first linear scaling factor.

As can be seen from fig. 9, under a certain stress F condition, the strain gauge value epsilon linearly changes with the temperature T in a first order, and a certain temperature To (typically 25 degrees) can be set as a reference temperature, at which the strain gauge value epsilon should be "0", and according To the above analysis, the strain gauge value epsilon can be regarded as a first order linear function of the temperature T, i.e., epsilon=k (T-To); k is a first linear scaling factor.

As can be seen from fig. 10, under a certain stress F condition, the change coefficient K of the strain gauge value epsilon with the temperature T and the change coefficient K with the temperature T also show an approximate first-order linear change, i.e. the change coefficient K of the strain gauge value epsilon with the temperature T is also a first-order linear function of the stress F (k=k (F) =c×f+co); c is a second linear scaling factor, co is a reference factor, and F is a target first linear scaling factor corresponding to 0.

Combining the two functional relationships To obtain a relationship between the stress F and the temperature T of the strain gauge numerical value epsilon, namely epsilon=E (F, T) =K (F) (T-To) = (C×F+Co) (T-To), and obtaining the relationship between epsilon and the stress F and the temperature T after expanding the relationship.

When the temperature T and the strain gage numerical value epsilon are known (when the strain gage is actually used for monitoring and measuring the stress, the two variables are known), namely, a first-order unitary equation (F) =0) containing the variable stress F is formed, and then the first-order equation type variable solution F can be obtained by utilizing algebraic merging, shifting and eliminating operations, and finally, the variable F which enables the equation to be established is the actual strain gage stress F after the temperature compensation of T is considered.

In order to solve adverse effects caused by factors such as difference of working conditions of each switch machine and the switch, difference of initial stress state of a rod piece when the acquisition equipment is installed, difference of fastening degree of bolts and the like, the acquisition equipment is installed in a four-switch state (in theory, the rod piece is not stressed in the state) based on the principle of one-machine calibration, the stress is ensured to be zero when the switch machine is initially installed, four installation bolts are fastened after the precision torque wrench is adopted to adjust the torque value to be the same when the clamp is installed, and the equipment is automatically calibrated based on zero setting and temperature drift suppression algorithms after the installation is completed. In practice, if one collection device determines the null-shift mathematical model and the temperature-shift mathematical model, the null-shift mathematical model and the temperature-shift mathematical model of the collection device cannot be directly used as the null-shift mathematical model and the temperature-shift mathematical model of the other collection device, and the null-shift mathematical model and the temperature-shift mathematical model of the other collection device need to be determined again by the corresponding methods.

On the basis of the switch stress monitoring system, the embodiment of the invention also provides another switch stress monitoring system, as shown in fig. 11, the upper computer 2 comprises: the first analysis module 21 and the second analysis module 22, wherein the first analysis module 21 is used for analyzing the first stress and the third stress to obtain conversion force, adhesion force and upwarp force; the second analysis module 22 is configured to analyze the second stress and the fourth stress to obtain a crawling force.

Specifically, the first analysis module 21 may obtain the conversion force and the adhesion force for each section interval stress by calculating the average value of the first stress and the third stress and analyzing the stress section by section; obtaining the upwarp force by calculating the difference value of the first stress and the third stress;

the second analysis module 22 obtains the crawling force by calculating the difference between the second stress and the fourth stress, and can determine the direction of the crawling force by judging the positive or negative of the difference.

Whether the switch is an internal locking switch or an external locking switch, the switch needs to output a certain force by the switch machine in the switching process to drive the switch rail/core rail to change the position, and the switch rail/core rail cannot be positioned from the reverse position to the reverse position or from the reverse position to the position. At this time, although the indication circuit can reflect the current state of the switch, the indication circuit is an electric signal and cannot reflect the mechanical state of the switch machine.

The output force on the switch machine action connecting rod is in a certain range (different types of switch machines and different specifications of switch data are different) during normal conversion, the collected data of the upper strain gauge and the lower strain gauge through the clamp 111 are also in a normal range, and once the output force of the switch machine is insufficient, the collected strain data of the upper strain gauge and the lower strain gauge are reduced to be below a preset early warning value, so that the early warning information of the insufficient output force of the switch machine can be given. The historical data of the pulling of the switch machine can be analyzed in a trend manner, so that the degradation trend of the mechanical state of the switch machine along with time is judged, trend early warning and the time point of possible faults of the switch machine in the future or the time point of possible maintenance requirement or the service life of the switch machine are given, and a basis is provided for operation and maintenance personnel to arrange maintenance and maintenance plans.

In addition, when foreign matter is blocked between the switch rail and the stock rail, the switch machine can not be normally locked when the foreign matter is more than 4mm, at the moment, a display circuit of the switch machine can not display signals, the situation that the switch is not pulled in place can be judged, meanwhile, the action current curve value of the existing signal centralized monitoring system exceeds the standard curve value, and accordingly, the occurrence of blocking faults can be judged. However, when the size of the blocking foreign matter is smaller than 4mm, the action current is not easy to distinguish under normal conditions, and even if advanced algorithms such as machine learning are added, the judgment of the action current curve on the blocking of the small foreign matter is still not accurate enough. Especially when the foreign matter is less than 2mm, the switch machine can be normally locked at this moment, and the indication circuit normally gives out indication signals, and everything is normal from the electric signal, and the blocking can not be identified, but the close contact quantity (gap between the switch rail and the stock rail) is more likely to exceed 1mm required by the standard at this moment. When the switch is blocked, the data of the switching force is obviously larger than the numerical value in normal switching, so that the switch blocking fault can be accurately identified.

The close force is the force required for keeping the switch tongue rail and the stock rail in a close state, the close force is provided by the switch locking device, when the mechanical structure state of the locking device is changed, such as bolt loosening caused by long-term driving vibration, insufficient locking force can be caused due to insufficient fastening of bolts after maintenance, and at the moment, close gaps between the switch tongue rail and the stock rail are enlarged due to insufficient locking force, so that driving safety is affected. Railway dimensions dictate that the force of the seal is maintained above 1000N. The collected data of the upper strain gauge and the lower strain gauge of the clamp 111 in the switch close state can be used for judging whether the switch close force meets the requirement or not, if the collected data is lower than 1000N, the pre-warning information is timely given, and maintenance personnel are reminded to carry out maintenance operation. In addition, trend analysis can be carried out on the collected historical data of the adhesion force, so that the degradation trend of the adhesion force in a future period of time can be judged, trend early warning and a time point when a fault possibly occurs in the future or a time point when maintenance is possibly needed can be given, and a basis is provided for operation and maintenance personnel to arrange maintenance and maintenance plans.

The switch machine action connecting rod is connected with the switch rail, when the switch rail is warped, a rod piece connected with one side of the switch rail is lifted up, an upward warping force is applied to the action connecting rod, and data of the upper strain gauge and the lower strain gauge of the clamp 111 are changed, so that whether the switch rail is warped up or not can be judged. Further, when two switch rails are tilted upwards at the same time, the tilting force is larger, and at the moment, the data collected by the upper strain gauge and the lower strain gauge of the clamp 111 have the largest change; when only the switch rail far away from the clamp 111 side is tilted upwards, the tilting force is smaller than that when two switch rails are tilted upwards simultaneously, the data change acquired by the upper strain gauge and the lower strain gauge of the clamp 111 is smaller, and when only the switch rail near the clamp 111 side is tilted upwards, the tilting force is minimum, and the data change acquired by the upper strain gauge and the lower strain gauge of the clamp 111 is minimum. From this it can be determined which point rail has been tilted up. In addition, after the three conditions are judged, the upward tilting degree of the switch rail can be further judged according to the upward tilting force, and the larger the upward tilting force is, the larger the upward tilting degree of the switch rail is, so that the different-level warning information is given, and maintenance personnel can conveniently judge the priority to be maintained according to the information.

The switch tongue is expanded with heat and contracted with cold or rolled for a long time due to the influence of the ambient temperature, so that the switch tongue is lengthened or shortened, the switch tongue is lengthened or shortened to drive the action connecting rod to deflect horizontally, and when the variation reaches a certain value (the requirement of the railway dimension gauge is not more than +/-20 mm), the switch switching resistance is increased. The point rail crawling is a slowly-changing parameter, and the crawling trend can be judged through the long-term data change on the left strain gauge and the right strain gauge of the clamp 111, so that the crawling trend early warning is given. When the strain gage data exceeds a threshold value (corresponding to a force generated by 20mm of crawling), alarm information is given. Based on the values and the changing directions of the left strain gauge and the right strain gauge, whether the switch rail crawls forwards or backwards can be further judged, so that a specific crawling direction is given, and operation and maintenance personnel are guided to maintain.

For example, when the point rail climbs forward, the left-side strain gauge value changes positively on the zero point basis, the right-side strain gauge value changes negatively on the zero point basis (and possibly vice versa, for example only), and when the point rail climbs backward, the left-side strain gauge value changes negatively on the zero point basis, the right-side strain gauge value changes positively on the zero point basis, whereby the direction of the point rail crawling can be determined.

The method is mainly applied to stress monitoring of the railway switch machine, the strain gauge sensor can capture resistance change in the switch machine conversion process and weak change of the close-fitting force in the close-fitting state, compared with a centralized monitoring system for monitoring action current mode, the direct force monitoring can reflect the mechanical state of equipment, meanwhile, through monitoring the force, accurate judgment of different degrees of blocking in the switch machine conversion process can be achieved, especially small foreign matter blocking below 4mm, action current is not easy to distinguish under normal conditions, even if advanced algorithms such as machine learning are added, the judgment of action current curves on the small foreign matter blocking is still inaccurate. In addition, the direct force monitoring can also realize early warning on the change of the close-contact force caused by the factors of environmental temperature, train impact and the like in the close-contact state.

Furthermore, the existing stress monitoring equipment is only used for monitoring the switching force of the switch machine, and lacks monitoring means for the crawling force and the upwarp force of the switch machine action connecting rod caused by the crawling and upwarp of the switch rail under static state. The method and the device can realize the monitoring of all the state parameters, and fill the gap of the stress monitoring of the switch machine, thereby realizing the visual and comprehensive monitoring of the mechanical properties of the switch machine under the dynamic and static working conditions. Meanwhile, for the problems of zero drift and temperature drift of the stress data acquisition device of the point switch, the zero drift and temperature drift can be restrained by embedding a zero drift restraining mathematical model and a temperature drift restraining mathematical model, and the accuracy and the reliability of stress monitoring data are improved. And an accurate monitoring data support is provided for daily maintenance of the switch machine.

The embodiment of the invention also provides a glue spraying method, as shown in fig. 12, which comprises the following steps:

step S102, the clamp conducts stress borne by the switch machine action connecting rod to each strain gauge respectively, so that each strain gauge outputs a corresponding weak voltage signal through a bridge type simulation module;

step S104, the acquisition module acquires each weak voltage signal and outputs a voltage signal corresponding to each weak voltage signal respectively;

step S106, the transmission module transmits the strain quantity corresponding to each voltage signal to the upper computer;

step S108, the upper computer monitors the stress of the switch machine based on each strain amount; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force.

The method for monitoring the stress of the switch machine comprises the following steps: the clamp conducts stress borne by the switch machine action connecting rod to a plurality of strain gauges arranged on the clamp, so that each strain gauge outputs a corresponding weak voltage signal through a bridge type simulation module, and the acquisition module outputs a voltage signal corresponding to each weak voltage signal; the transmission module transmits the strain quantity corresponding to each voltage signal to the upper computer; the upper computer monitors the stress of the switch machine based on each strain; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force. According to the mode, the plurality of strain gauges are deployed on the clamp tightly attached to the action connecting rod of the switch machine, so that the switching force and the close stress of the switch machine can be detected, meanwhile, the crawling force and the upwarp force can be detected, more stress data of the switch machine can be obtained compared with the prior art, and the visual and comprehensive monitoring of the mechanical performance of the switch machine under the dynamic and static working conditions can be realized.

The method for monitoring the stress of the switch machine, provided by the embodiment of the invention, has the same implementation principle and technical effects as those of the embodiment of the stress monitoring system of the switch machine, and the corresponding content in the embodiment of the stress monitoring system of the switch machine can be referred to in the embodiment part of the method for monitoring the stress of the switch machine.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those skilled in the art in the specific case.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present disclosure, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present application, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the invention and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific direction, be configured and operated in the specific direction, and thus should not be construed as limiting the present application.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (10)

1. A switch machine stress monitoring system, the monitoring system comprising: the switch machine stress data acquisition device and the upper computer are in communication connection with each other; the switch machine stress data acquisition device comprises: the sensing module, the acquisition module and the transmission module are connected in sequence; the sensing module includes: a clamp, and a plurality of strain gauges mounted on the clamp; the clamp is arranged on the action connecting rod of the switch machine; the clamp is tightly attached to the action connecting rod of the switch machine;

The clamp is used for respectively transmitting stress borne by the switch machine action connecting rod to each strain gauge so that each strain gauge outputs a corresponding weak voltage signal through the bridge type simulation module;

the acquisition module is used for acquiring each weak voltage signal and outputting a voltage signal corresponding to each weak voltage signal respectively;

the transmission module is used for transmitting the strain quantity corresponding to each voltage signal to the upper computer;

the upper computer is used for monitoring the stress of the switch machine based on each strain amount; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force.

2. The switch machine stress monitoring system of claim 1, wherein the plurality of strain gages comprises: a first strain gage, a second strain gage, a third strain gage, and a fourth strain gage; the clamp comprises a first symmetrical structural member and a second symmetrical structural member; openings matched with the shapes of the action connecting rods are formed in the inner sides of the first symmetrical structural member and the second symmetrical structural member and are used for being tightly attached to the action connecting rods;

the first symmetrical structure includes: the first connecting bridge, the second connecting bridge and two symmetrical first U-shaped structures; the two first U-shaped structures are connected through the first connecting bridge and the second connecting bridge;

The second symmetrical structure includes: the third connecting bridge, the fourth connecting bridge and two symmetrical second U-shaped structures; the two second U-shaped structures are connected through the third connecting bridge and the fourth connecting bridge;

the first connecting bridge is attached to the upper surface of the action connecting rod, the second connecting bridge is attached to the left surface of the action connecting rod, the third connecting bridge is attached to the lower surface of the action connecting rod, and the fourth connecting bridge is attached to the right surface of the action connecting rod;

the first strain gauge is attached to the first connecting bridge, the second strain gauge is attached to the second connecting bridge, the third strain gauge is attached to the third connecting bridge, and the fourth strain gauge is attached to the fourth connecting bridge.

3. The switch machine stress monitoring system of claim 1, wherein the acquisition module comprises: the amplifying and filtering module and the ADC conversion module are connected in sequence;

the amplifying and filtering module is used for amplifying and filtering each weak voltage signal to obtain a voltage processing signal corresponding to each weak voltage signal;

and the ADC conversion module is used for carrying out analog-to-digital conversion processing on each voltage processing signal to obtain a voltage signal corresponding to each voltage processing signal.

4. The switch machine stress monitoring system of claim 1, wherein the monitoring system further comprises a processing module; the acquisition module is connected with the transmission module through the processing module;

the processing module is used for receiving each voltage signal acquired by the acquisition module, converting each voltage signal into a corresponding strain quantity, and calculating based on a pre-integrated zero drift suppression mathematical model to obtain a strain quantity check value corresponding to each strain quantity respectively; the null shift inhibition mathematical model is obtained by the following steps:

when the action connecting rod is not stressed, a first offset and a second offset of each strain are obtained through a preset first calibration method and a preset second calibration method;

the null shift suppression mathematical model is determined based on the first offset and the second offset.

5. The switch machine stress monitoring system of claim 4, wherein the switch machine stress data acquisition device further comprises a power module for powering the sensing module, the acquisition module, the transmission module, the processing module.

6. The switch machine stress monitoring system of claim 4, wherein the switch machine stress data acquisition device further comprises a temperature sensor module for acquiring environmental temperature information.

7. The switch machine stress monitoring system of claim 1, wherein the switch machine stress data acquisition device further comprises a vibration sensor module for receiving a vibration signal from the action bar to control the switch machine stress data acquisition device to begin operation based on the vibration signal.

8. The switch machine stress monitoring system of claim 6, wherein the transmission module is configured to transmit each of the strain gauge check values and the temperature information to the host computer;

the upper computer calculates each strain check value and the temperature information according to a preset temperature drift suppression mathematical model to obtain a first stress, a second stress, a third stress and a fourth stress;

the temperature drift inhibition mathematical model is obtained by the following steps:

acquiring a first-order linear function between a strain check value obtained by the processing module and the ambient temperature based on a preset reference temperature and a preset first linear proportionality coefficient;

acquiring a second first-order linear function between the first linear scaling factor and the stress born by the strain gauge based on a preset reference coefficient and a preset second linear scaling factor;

Substituting the second first-order linear function into the first-order linear function to obtain the temperature drift suppression mathematical model.

9. The switch machine stress monitoring system of claim 8, wherein the upper computer comprises: the first analysis module is used for analyzing the first stress and the third stress to obtain the conversion force, the adhesion force and the upwarp force; the second analysis module is used for analyzing the second stress and the fourth stress to obtain the crawling force.

10. A method for monitoring stress of a switch machine, the method comprising:

the clamp conducts stress borne by the switch machine action connecting rod to each strain gauge respectively, so that each strain gauge outputs a corresponding weak voltage signal through the bridge type simulation module;

the acquisition module acquires each weak voltage signal and outputs a voltage signal corresponding to each weak voltage signal;

the transmission module transmits the strain quantity corresponding to each voltage signal to the upper computer;

the upper computer monitors the stress of the switch machine based on each strain amount; wherein the stress comprises: conversion force, adhesion force, crawling force and upwarp force.