Intelligent sleepers and methods for monitoring foreign object intrusion and damage levels in ballasted tracks

Abstract

This invention relates to an intelligent railway sleeper and method for monitoring foreign object intrusion and damage to ballasted tracks. The method includes a ballasted track sleeper and a foreign object intrusion device, wherein the foreign object intrusion device comprises a foreign object monitoring module, a foreign object positioning module, and a foreign object alarm module. The foreign object intrusion device is installed at the top center of the ballasted track sleeper. The foreign object monitoring module is installed at the bottom of the foreign object alarm module, and the foreign object positioning module is installed on the upper surface of the foreign object alarm module. The modules communicate with each other. The foreign object monitoring module monitors micro-vibration signals and acquires foreign object intrusion parameters. The foreign object positioning module monitors influencing factors on the ballasted track sleeper and determines the location and coverage area of ​​the foreign object intrusion. The foreign object alarm module receives data from the modules, takes photos of the foreign object intrusion site, formulates a maintenance plan, and sends an alarm to the railway maintenance department's big data center. Compared with existing technologies, this invention achieves all-weather, high-precision real-time monitoring of railway foreign object intrusion.

Description

Technical Field

[0001] This invention relates to the fields of slope engineering and track quality monitoring, and in particular to an intelligent sleeper and method for monitoring foreign object intrusion and the degree of damage to ballasted tracks. Background Technology

[0002] Currently, there are two main measures for monitoring foreign object intrusion incidents on railways. The first is manual inspection, relying on protective netting combined with periodic manual checks to protect the railway from foreign object intrusion. However, this method cannot guarantee timeliness and is very resource-intensive. Protective netting can only prevent some rocks from falling into the railway, not highly mobile objects such as animals or vehicles. The second method is video monitoring, installing video devices on lines prone to foreign object intrusion. Real-time analysis of the collected video data is then performed manually to check for intrusions. This method is susceptible to severe weather, significantly reducing or even eliminating its monitoring capabilities. Furthermore, manual video monitoring is prone to missed detections due to fatigue, and the automation level is low. Both methods rely on external monitoring and cannot guarantee accuracy or real-time performance, leaving significant gaps in track safety monitoring. Moreover, there is currently no research or modification of foreign object intrusion monitoring technology at the level of ballasted track sleepers. Summary of the Invention

[0003] The purpose of this invention is to overcome the defects of the prior art and provide an intelligent sleeper and method for monitoring foreign object intrusion and the degree of damage to ballasted tracks.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A smart sleeper for monitoring foreign object intrusion and the degree of damage to ballasted tracks includes a ballasted track sleeper and a foreign object intrusion device, wherein the foreign object intrusion device is divided into a foreign object monitoring module, a foreign object positioning module and a foreign object alarm module.

[0006] The foreign object intrusion limiting device is installed at the top center of the ballast track sleeper;

[0007] The foreign object monitoring module is installed at the bottom of the foreign object alarm module, and the foreign object positioning module is installed on the upper surface of the foreign object alarm module. The modules communicate with each other.

[0008] The foreign object monitoring module is used to monitor the micro-vibration signal generated by the impact of foreign objects at the landing point, obtain foreign object intrusion limit parameters, and analyze the foreign object intrusion limit parameters;

[0009] The foreign object location module is used to monitor the impact of environmental and external factors on ballasted track sleepers and determine the location and coverage area of ​​foreign objects intruding into the track.

[0010] The foreign object alarm module is used to receive data from the foreign object monitoring module and the foreign object positioning module, take pictures of the foreign object intrusion site, form a corresponding maintenance plan, and send an alarm to the engineering section's big data department.

[0011] Furthermore, spiral ribs are provided on the shoulders on both sides of the ballasted track sleeper, and an installation groove for installing a foreign object intrusion device is provided at the top middle position. A protective shell is installed on the installation groove. The protective shell has reserved holes along the longitudinal direction of the ballasted track sleeper for connecting the foreign object monitoring module. The foreign object monitoring module, foreign object alarm module and foreign object positioning module are installed laterally along the ballasted track sleeper and stacked from bottom to top before being placed in the protective shell and fixedly installed in the installation groove.

[0012] Furthermore, the foreign object monitoring module includes a fiber Bragg grating (FRP-OF) vibration sensor and a fiber Bragg grating (FRP-OF) smart stirrup. The fiber Bragg grating (FRP-OF) vibration sensor is fitted with a fiber Bragg grating (FRP-OF) smart stirrup. The fiber Bragg grating (FRP-OF) vibration sensor is connected to the bottom of the foreign object alarm module. The type of fiber Bragg grating (FRP-OF) vibration sensor is a displacement sensor, a velocity sensor, or an acceleration sensor.

[0013] Furthermore, vibration-strain measuring points are set at the middle positions of the front, rear, and bottom of the fiber optic grating FRP-OF smart stirrup. The vibration-strain measuring points at the front and rear monitor the deformation and longitudinal resistance capacity of the sleeper box after being severely damaged by foreign object intrusion, as well as the damage to the side of the sleeper. The vibration-strain measuring points at the bottom monitor the longitudinal and transverse resistance capacity of the track bed, ballast, and sleeper at the bottom of the sleeper, as well as the bending moment and damage inside the sleeper.

[0014] Furthermore, the foreign object location module includes an environmental sensor and a radar, which are mounted on the surface of the foreign object alarm module. The environmental sensor incorporates a rain sensor, a wind speed sensor, a seismic detector, and a train sensor.

[0015] Furthermore, the foreign object alarm module includes a demodulation alarm and an external interface device.

[0016] Furthermore, the method for monitoring foreign object intrusion and ballast track damage in a smart sleeper includes the following steps:

[0017] S1. The foreign object monitoring module monitors the micro-vibration signal generated by the impact of a foreign object on the landing point. By analyzing the signal, it judges the change of the foreign object intrusion limit parameter and transmits the data to the foreign object alarm module and the foreign object positioning module.

[0018] S2. The foreign object location module monitors the influence of environmental and external factors, uses the propagation characteristics of vibration waves and receives its own electromagnetic waves to determine the location and coverage area of ​​the foreign object intrusion, and transmits the data to the foreign object monitoring module and the foreign object alarm module.

[0019] S3. The foreign object monitoring module determines the damage status of the ballasted track and transmits the determination result to the foreign object alarm module.

[0020] S4. The foreign object alarm module combines the data transmitted by the foreign object monitoring module and the foreign object positioning module to complete the data collection and analysis, and takes photos or videos of the foreign object intrusion incident site to establish a corresponding maintenance plan.

[0021] S5, the foreign object alarm module transmits the corresponding maintenance plan to the track maintenance section's big data application window.

[0022] Furthermore, the foreign object monitoring module is equipped with a fiber Bragg grating FRP-OF vibration sensor (3) and a fiber Bragg grating FRP-OF smart stirrup (7). When a foreign object intrusion event occurs, the fiber Bragg grating FRP-OF vibration sensor (3) monitors the micro-vibration signal generated by the impact of the foreign object on the landing point, and analyzes it based on the endpoint detection method of short-time energy of the signal, such as: foreign object intrusion time, vibration duration, vibration frequency, attenuation coefficient and waveform correlation coefficient. The fiber Bragg grating FRP-OF vibration sensor (3) converts the effective data signal into the mass, volume, quantity and energy parameters of the foreign object, classifies the foreign object intrusion vibration event into four types: single foreign object intrusion vibration, foreign object intrusion bouncing vibration, multiple foreign object intrusion vibration and collapse vibration, and performs frame processing by determining the frame length and frame shift data, sets an appropriate energy threshold, and then calculates the short-time energy of each frame. The calculation method of short-time energy is as follows: let the signal x of the m-th frame after frame division be... m The short-time energy of {x(i)} (i = 1, 2, ..., N) is E. m Let N represent the length of each frame of signal, then:

[0023]

[0024] The signal time series is processed into numbers between [-1, 1] using the mapminmax function. Assume the data x = [x1, x2, ..., x...]. n ], y = [y1, y2, ..., y n ], and y = mapminmax(x), then we have:

[0025]

[0026] Among them, y max =1, y min =-1, substituting it in, we get:

[0027]

[0028] Each frame of data is detected one by one using a pre-set energy threshold. If the threshold is exceeded, the frame of data is calibrated as the endpoint of the valid data signal, and then the valid data segment is finally determined for subsequent data processing and calculation.

[0029] The fiber vibration or pressure of the fiber optic grating FRP-OF smart hoop (7) acts on the sensing optical cable, causing changes in the fiber core diameter, fiber core refractive index, and fiber length. These changes alter the phase of the transmitted light in the sensing optical cable, which is then converted into a fiber vibration signal carrying external behavioral information after photoelectric conversion. When the foreign object monitoring module meets the phase matching condition, the fiber harmonic array wavelength, grating resonant wavelength offset, and strain change relationship are calculated using the following formula:

[0030] λ B =2n e Tλ B =2n e T

[0031] Δλ B =2Δn e T+2n e ΔT

[0032]

[0033] In the formula, λ B n is the resonant wavelength of the fiber optic grating. e λ is the effective refractive index of the fiber grating propagation mode; T is the grating period; ε is the test strain value; λ is the output wavelength; λ0 is the initial wavelength; K b is the strain coefficient.

[0034] Furthermore, the foreign object location module is equipped with an environmental sensor (5) and a radar (6). The environmental sensor (5) generates an environmental weather dataset to determine the degree of influence of the environment and weather on foreign object intrusion events and predict the degree of damage to the ballast track. The environmental sensor (5) acquires data on the impact of external factors such as train operation, track maintenance personnel's maintenance work, and animal intrusion, and processes it to form a preliminary factor dataset. If no foreign object intrusion event occurs, it is stored as a normal factor in the foreign object alarm module. If a foreign object intrusion event occurs, the preliminary factor dataset is combined with the environmental weather dataset and transmitted to the foreign object alarm module to assist the foreign object alarm module in determining the alarm type.

[0035] According to the different initial foreign object intrusion positions, the radar (6) divides the foreign object intrusion vibration into rail vibration, sleeper vibration and ballast vibration. Because the different initial foreign object intrusion positions cause different micro-vibration signals, the complex signals caused by external factors are simplified by frequency domain analysis. According to the requirements, the signal strength information of different frequencies contained in a signal is extracted for analysis. By combining the foreign object monitoring module, the propagation characteristics of vibration waves and the electromagnetic waves emitted by the receiver are used to determine the foreign object intrusion position and coverage area by combining active and passive positioning methods.

[0036] Furthermore, the foreign object alarm module is equipped with a demodulation alarm device (4) and an external connection device. The demodulation alarm device (4) has 5G technology support function. Combined with the parameters monitored by the foreign object monitoring module and the foreign object positioning module, it synchronously receives the output signals and datasets of various devices and different unit types, and realizes the identification and analysis of the causes of foreign object vibration events, such as vibration caused by foreign object intrusion, vibration caused by collapse and vibration caused by train, forming a graded alarm mechanism for foreign object intrusion. At the same time, it connects to external docking devices such as satellites and active and passive protection nets to take high-definition pictures of the location where foreign object intrusion occurs on the ballasted track, forming a maintenance plan, including the number of maintenance personnel and the basic parameters of the types of tools required, and transmits them to the engineering section's big data application window in the form of SMS and GPRS.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. This invention provides a ballast track sleeper 1 and a foreign object intrusion device, wherein the foreign object intrusion device is divided into a foreign object monitoring module, a foreign object positioning module, and a foreign object alarm module. The foreign object intrusion device is installed at the top center of the ballast track sleeper 1, the foreign object monitoring module is installed at the bottom of the foreign object alarm module, and the foreign object positioning module is installed on the upper surface of the foreign object alarm module. The modules transmit signals to each other, enabling the detection of foreign object intrusion in real time, thus ensuring the accuracy and real-time nature of foreign object intrusion monitoring.

[0039] 2. The present invention provides an installation slot on the ballasted track sleeper 1, on which a protective shell is installed. The foreign object monitoring module, the foreign object positioning module, and the foreign object alarm module are installed laterally along the ballasted track sleeper 1 and stacked from bottom to top before being placed in the protective shell. The protective shell can prevent the foreign object intrusion device from being damaged by severe weather, thereby achieving the monitoring of track safety.

[0040] 3. The foreign object monitoring module of this invention includes a fiber optic grating FRP-OF vibration sensor 3 and a fiber optic grating FRP-OF smart stirrup 7. By setting vibration-strain measuring points 8 at the middle positions of the front, rear and bottom of the fiber optic grating FRP-OF smart stirrup 7, the resistance capacity of the sleeper box of the ballasted track sleeper 1, the damage on the side of the sleeper and the resistance capacity at the bottom of the sleeper are monitored respectively, realizing comprehensive monitoring of the ballasted track sleeper 1.

[0041] 4. The foreign object alarm module of this invention includes a demodulation alarm 4 and an external docking device. The demodulation alarm 4 issues an alarm when it detects a foreign object intruding into the limit and transmits the maintenance plan through the external device. This eliminates the need for manual inspection, reduces the consumption of manpower and resources, and ensures timeliness.

[0042] 5. The foreign object positioning module of the present invention includes an environmental sensor 5 and a radar 6. The environmental sensor 5 has a built-in rain sensor, wind speed sensor, earthquake detector and train sensor to monitor the impact of environmental factors on the ballast track sleeper 1 in real time. The radar 6 determines the location and coverage area of ​​the foreign object intrusion, so as to achieve high-precision positioning of the foreign object intrusion. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of the present invention;

[0044] Figure 2 This is a front view of the structure of the present invention;

[0045] Figure 3 This is a top view of the structure of the present invention;

[0046] Figure 4 This is a schematic diagram of the foreign object monitoring system of the present invention;

[0047] Figure 5 This is a schematic diagram of the foreign object positioning system and foreign object alarm system of the present invention;

[0048] Figure 6 This is a detailed schematic diagram of the foreign object intrusion restriction system of the present invention.

[0049] The following are the labels in the diagram: 1. Ballast track sleeper; 2. Spiral reinforcement; 3. Fiber Bragg grating FRP-OF vibration sensor; 4. Demodulation alarm device; 5. Environmental sensor; 6. Radar; 7. Fiber Bragg grating FRP-OF smart stirrup; 8. Vibration-strain measuring point. Detailed Implementation

[0050] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0051] A smart sleeper for monitoring foreign object intrusion and damage to ballasted track includes a ballasted track sleeper 1 and a foreign object intrusion device. The foreign object intrusion device consists of a foreign object monitoring module, a foreign object positioning module, and a foreign object alarm module. The foreign object intrusion device is installed at the top center of the ballasted track sleeper 1. The foreign object monitoring module is installed at the bottom of the foreign object alarm module, and the foreign object positioning module is installed on the upper surface of the foreign object alarm module. The modules communicate with each other. The foreign object monitoring module monitors the micro-vibration signals generated by the impact of foreign objects at the impact point, acquires foreign object intrusion parameters, and analyzes the foreign object intrusion parameters. The foreign object positioning module monitors the influence of environmental and external factors on the ballasted track sleeper 1 and determines the location and coverage area of ​​the foreign object intrusion. The foreign object alarm module receives data from the foreign object monitoring module and the foreign object positioning module, takes pictures of the foreign object intrusion site, formulates a corresponding maintenance plan, and sends an alarm to the engineering section's big data department.

[0052] Spiral ribs 2 are provided on the shoulders of both sides of the ballasted track sleeper 1, and an installation groove for installing a foreign object intrusion device is provided at the top middle position. A protective shell is installed on the installation groove. The protective shell has reserved holes for connecting the foreign object monitoring module along the longitudinal direction of the ballasted track sleeper 1. The foreign object monitoring module, foreign object alarm module and foreign object positioning module are installed laterally along the ballasted track sleeper 1 and stacked from bottom to top before being placed in the protective shell and fixedly installed in the installation groove.

[0053] The foreign object monitoring module includes a fiber Bragg grating FRP-OF vibration sensor 3 and a fiber Bragg grating FRP-OF smart stirrup 7. The fiber Bragg grating FRP-OF vibration sensor 3 is fitted with the fiber Bragg grating FRP-OF smart stirrup 7. The fiber Bragg grating FRP-OF vibration sensor 3 is connected to the bottom of the foreign object alarm module. The fiber Bragg grating FRP-OF vibration sensor 3 is a displacement sensor, velocity sensor or acceleration sensor.

[0054] Vibration-strain measuring points 8 are set at the middle positions of the front, rear, and bottom of the fiber optic grating FRP-OF smart stirrup 7. The vibration-strain measuring points 8 at the front and rear monitor the deformation and longitudinal resistance capacity of the sleeper box after being severely damaged by foreign object intrusion, as well as the damage to the side of the sleeper. The vibration-strain measuring point 8 at the bottom monitors the longitudinal and transverse resistance capacity of the bottom track bed, ballast, and sleeper, as well as the bending moment and damage inside the sleeper.

[0055] The foreign object location module includes an environmental sensor 5 and a radar 6. The environmental sensor 5 and radar 6 are installed on the surface of the foreign object alarm module. The environmental sensor 5 has a built-in rain sensor, wind speed sensor, earthquake detector and train sensor.

[0056] The foreign object alarm module includes a demodulation alarm device 4 and external docking equipment.

[0057] A method for monitoring foreign object intrusion and ballast track damage levels in smart railway sleepers includes the following steps:

[0058] S1. The foreign object monitoring module monitors the micro-vibration signal generated by the impact of a foreign object on the landing point. By analyzing the signal, it judges the change of the foreign object intrusion limit parameter and transmits the data to the foreign object alarm module and the foreign object positioning module.

[0059] S2. The foreign object location module monitors the influence of environmental and external factors, uses the propagation characteristics of vibration waves and receives its own electromagnetic waves to determine the location and coverage area of ​​the foreign object intrusion, and transmits the data to the foreign object monitoring module and the foreign object alarm module.

[0060] S3. The foreign object monitoring module determines the damage status of the ballasted track and transmits the determination result to the foreign object alarm module.

[0061] S4. The foreign object alarm module combines the data transmitted by the foreign object monitoring module and the foreign object positioning module to complete the data collection and analysis, and takes photos or videos of the foreign object intrusion incident site to establish a corresponding maintenance plan.

[0062] S5, the foreign object alarm module transmits the corresponding maintenance plan to the track maintenance section's big data application window.

[0063] The foreign object monitoring module is equipped with a fiber Bragg grating (FRP-OF) vibration sensor 3 and a fiber Bragg grating (FRP-OF) smart stirrup 7. When a foreign object intrusion event occurs, the FRP-OF vibration sensor 3 monitors the micro-vibration signal generated by the impact of the foreign object at the impact point. It analyzes the signal based on the endpoint detection method using short-time energy, such as the foreign object intrusion time, vibration duration, number of vibrations, attenuation coefficient, and waveform correlation coefficient. The FRP-OF vibration sensor 3 converts the effective data signal into parameters of the foreign object's mass, volume, quantity, and energy. It classifies foreign object intrusion vibration events into four types: single foreign object intrusion vibration, foreign object intrusion bouncing vibration, multi-foreign object intrusion vibration, and collapse vibration. It performs frame segmentation by determining the frame length and frame shift data, sets an appropriate energy threshold, and then calculates the short-time energy of each frame. The calculation method for short-time energy is as follows: Let the signal x in the m-th frame after segmentation... m The short-time energy of {x(i)} (i = 1, 2, ..., N) is E. m Let N represent the length of each frame of signal, then:

[0064]

[0065] The signal time series is processed into numbers between [-1, 1] using the mapminmax function. Assume the data x = [x1, x2, ..., x...]. n ], y = [y1, y2, ..., y n], and y = mapminmax(x), then we have:

[0066]

[0067] Among them, y max =1, y min =-1, substituting it in, we get:

[0068]

[0069] Each frame of data is detected one by one using a pre-set energy threshold. If the threshold is exceeded, the frame of data is calibrated as the endpoint of the valid data signal, and then the valid data segment is finally determined for subsequent data processing and calculation.

[0070] The fiber vibration or pressure of the FRP-OF smart stirrup 7 acts on the sensing optical cable, causing changes in the fiber core diameter, fiber core refractive index, and fiber length. These changes alter the phase of the light transmitted in the sensing optical cable, which, after photoelectric conversion, is transformed into an optical fiber vibration signal carrying information about external behavior. When the foreign object monitoring module meets the phase matching condition, the fiber harmonic array wavelength, the grating resonant wavelength offset, and the strain change relationship are calculated using the following formula:

[0071] λ B =2n e Tλ B =2n e T

[0072] Δλ B =2Δn e T+2n e ΔT

[0073]

[0074] In the formula, λ B n is the resonant wavelength of the fiber optic grating. e λ is the effective refractive index of the fiber grating propagation mode; T is the grating period; ε is the test strain value; λ is the output wavelength; λ0 is the initial wavelength; K b is the strain coefficient.

[0075] The foreign object location module is equipped with an environmental sensor 5 and a radar 6. The environmental sensor 5 generates an environmental weather dataset to determine the degree of impact of the environment and weather on foreign object intrusion events and predict the degree of damage to the ballasted track. For the impact of external factors such as train operation, track maintenance personnel's work, and animal intrusion, the environmental sensor 5 acquires data, processes it to form a preliminary factor dataset, and if no foreign object intrusion event occurs, it is stored as a normal factor in the foreign object alarm module. If a foreign object intrusion event occurs, the preliminary factor dataset is combined with the environmental weather dataset and transmitted to the foreign object alarm module to assist the foreign object alarm module in determining the alarm type.

[0076] Radar 6 classifies foreign object intrusion vibrations into rail vibrations, sleeper vibrations, and ballast vibrations based on their initial intrusion locations. These vibrations generate different micro-vibration signals due to their different initial intrusion locations. By using frequency domain analysis, the complex signals caused by external factors are simplified. The signal strength information of different frequencies contained in a signal is extracted and analyzed according to the requirements. By combining the foreign object monitoring module with the propagation characteristics of vibration waves and the electromagnetic waves emitted by the receiver itself, the location and coverage area of ​​the foreign object intrusion are determined through a combination of active and passive positioning methods.

[0077] The foreign object alarm module is equipped with a demodulation alarm device 4 and external connection devices. The demodulation alarm device 4 has 5G technology support. Combined with the parameters monitored by the foreign object monitoring module and the foreign object positioning module, it synchronously receives output signals and datasets from various devices and different types of units to identify and analyze the causes of foreign object vibration events, such as vibrations caused by foreign object intrusion, vibrations caused by collapse, and vibrations caused by trains. This forms a graded alarm mechanism for foreign object intrusion. At the same time, it connects to external docking devices such as satellites and active and passive protection nets to take high-definition pictures of the location of foreign object intrusion events on ballasted tracks, forming a maintenance plan, including the basic parameters of the number of maintenance personnel and the types of tools required. All of these are transmitted to the track maintenance section's big data application window in the form of SMS and GPRS.

[0078] like Figures 1 to 5 A smart sleeper for monitoring foreign object intrusion and the degree of damage to ballasted track includes a Type III prestressed concrete ballasted track sleeper with shoulder 1, a spiral reinforcement 2, a fiber optic grating FRP-OF vibration sensor 3, a 5G demodulation alarm 4, an environmental sensor 5, a radar 6, a fiber optic grating FRP-OF smart hoop 7, and a vibration-strain measuring point 8.

[0079] Ballasted track sleepers 1 include the new Type II, Type III, and Type IV sleepers widely used on the line. Taking the Type III prestressed concrete sleeper 1, which is widely used in mountainous areas, tunnel lines, and high-speed and heavy-load lines, as an example.

[0080] The foreign object intrusion device is divided into a foreign object monitoring module, a foreign object location module, and a foreign object alarm module. It encompasses multiple modules including micro-vibration, location, analysis, and alarm functions, and is completed collaboratively by multiple devices. The foreign object monitoring module consists of an upper structure and a lower structure, comprising a fiber optic grating-OF vibration sensor 3 and a fiber optic grating-OF smart stirrup 7, respectively. The foreign object location module includes an environmental sensor 5 and a radar 6. The foreign object alarm module includes a 5G demodulation alarm device 4, as well as external docking equipment and engineering section big data, etc.

[0081] A foreign object intrusion device mounting groove is provided at the top center of the ballasted track sleeper body 1. The mounting groove should not be too deep, just enough to fit the size of the protective shell. The foreign object monitoring module, foreign object alarm module, and foreign object positioning module are installed laterally along the sleeper and stacked from bottom to top, then placed in the corresponding protective shell and fixedly installed in the foreign object intrusion device mounting groove.

[0082] Ballasted track sleepers 1 can be mass-produced and laid in ballasted track areas prone to foreign object intrusion, such as mountainous regions and tunnels. This is especially important for monitoring the impact of foreign object intrusion on railway lines in mountainous areas and tunnels, which is a consequence of the rapid development of high-speed and heavy-haul railways. The intelligent sleepers 1 work together to analyze and process data. When one sleeper 1 is struck by a foreign object and its intrusion detection device malfunctions, nearby sleepers 1 can still function effectively, monitoring the impact energy of the foreign object and analyzing the overall area affected by the intrusion and the resulting economic losses.

[0083] Multiple smart sleepers 1 can be installed, and multiple sleepers 1 are laid sequentially on the monitoring section of the ballasted track. In actual application, the position and number of smart sleepers 1 can be reasonably set according to the location and range of the section to be monitored. The smart sleepers 1 are laid in the same way as other ordinary sleepers, and are laid sequentially on the ballasted track at equal intervals.

[0084] The upper structure of the foreign object monitoring module is a fiber optic grating FRP-OF vibration sensor 3, which is a displacement sensor, velocity sensor or acceleration sensor, or any vibration sensor in the prior art;

[0085] After the fiber optic grating FRP-OF vibration sensor 3 is installed on the sleeper 1 and put into service, it can accurately monitor and alarm foreign objects that fall on the rail, sleeper, or track bed with energy higher than 4 kilojoules, i.e. 80 kilograms, and fall from a height of more than 5 meters.

[0086] The fiber Bragg grating (FRP-OF) vibration sensor 3 can monitor the micro-vibration signal generated by the impact of a foreign object at the impact point when a foreign object intrusion event occurs. It also analyzes various parameters of the foreign object intrusion event based on the endpoint detection method using short-time signal energy. The data is segmented into frames by determining the frame length and frame shift, and an appropriate energy threshold is set. Then, the short-time energy of each frame is calculated. The calculation method for the short-time energy is as follows: Let the signal of the m-th frame after segmentation be x... m The short-time energy of {x(i)} (i = 1, 2, ..., N) is E. m N represents the length of each frame of signal, then

[0087]

[0088] To simplify calculations, the parameters are normalized. The signal time series is processed using the mapminmax function to convert it into numbers between [-1, 1]. Assume the data x = [x1, x2, ..., x...]. n ], y = [y1, y2, ..., y n ], and y = mapminmax(x), then we have:

[0089]

[0090] Among them, y max =1, y min =-1, substituting it in, we get:

[0091]

[0092] Each frame of data is tested one by one using a pre-set energy threshold. If the threshold is exceeded, the frame of data is calibrated as the endpoint of the valid data signal, and then the valid data segment is finally determined for subsequent data processing calculations.

[0093] The fiber optic grating FRP-OF vibration sensor 3 divides the effective data signal into data such as the mass, volume, and quantity of foreign objects. With advantages such as strong stability and strong anti-interference ability, it avoids false alarms when there is slight shaking or small foreign object intrusion that is not enough to cause damage to the railway. It classifies foreign object intrusion vibration events into four types: single foreign object intrusion vibration, foreign object intrusion bouncing vibration, multiple foreign object intrusion vibration, and collapse vibration.

[0094] Microseismic signals are all non-stationary and nonlinear signals. Due to the different generation mechanisms of various signals, they exhibit different characteristics in the time domain, frequency domain, time-frequency domain, and Hilbert domain. Time-domain analysis directly analyzes and extracts features from the time series of signals, offering advantages such as simplicity, intuitiveness, and ease of understanding.

[0095] Taking vibration with multiple foreign objects intruding as an example, its time-domain characteristic parameters should include the following parameters:

[0096] Vibration amplitude, that is, the maximum value that vibration can reach;

[0097] The number of oscillations is defined as the process by which a signal goes from a stable state to a state of large fluctuations and then back to a stable state as one oscillation.

[0098] The duration of the first oscillation is defined as the length of time from the start position to the end position of the first oscillation of the signal.

[0099] The total duration of vibration is defined as the time elapsed from the start of the first vibration of a signal to the end of the last vibration.

[0100] The duration of the steady-state phase is defined as the sum of the durations of all vibrations of the signal minus the total duration of the vibration.

[0101] The foreign object monitoring module includes a fiber Bragg grating (FRP-OF) vibration sensor 3 and a fiber Bragg grating (FRP-OF) smart stirrup 7, both composed of FRP material wrapping the fiber Bragg grating sensing points. The FRP (fiber-reinforced composite plastic) is made of a composite of various materials such as glass fiber, aramid fiber, carbon fiber, and basalt fiber.

[0102] The lower structure of the foreign object monitoring module is a fiber optic grating FRP-OF smart hoop 7. Its manufacturing process involves pultruding and extruding the fiber bundle impregnated with resin, followed by epoxy resin thermal curing. The optical fiber written into the grating is placed in the center hole of the bundle combining disk and cured together with the resin.

[0103] The FRP-OF smart stirrup 7 consists of FRP material wrapping the fiber grating sensing points, with multiple grating sensing points on a single fiber. By using Raman optical time-domain reflectometry, and analyzing the modulation coefficients of scattered light at different frequencies and the measured luminous flux, parameter changes can be determined.

[0104] The lower structure of the foreign object monitoring module is arranged longitudinally in the middle of the sleeper 1, and its upper part is connected to the upper structure of the foreign object monitoring module; the protective shell has a reserved hole along the longitudinal direction of the sleeper, and the fiber optic grating FRP-OF smart stirrup 7 can be inserted to connect with its upper structure and is perpendicular to the upper structure.

[0105] The lower structure of the foreign object monitoring module consists of a fiber optic grating (FRP-OF) smart stirrup 7 with a vibration-strain measurement point 8 at the front, rear, and bottom center. The optical fiber is based on the principle of combining Mach-Zehnder and Bragg fibers. Vibration or pressure acting on the sensing optical cable causes changes in the fiber core diameter, refractive index, and length. These changes alter the phase of the light transmitted in the sensing optical cable. After photoelectric conversion, these changes in optical characteristics are transformed into an optical fiber vibration signal carrying information about external behavior.

[0106] When the foreign object monitoring module meets the phase matching condition, the offset of the fiber harmonic array wavelength, the grating resonant wavelength, and the strain change relationship are calculated using the following formula:

[0107] λ B =2n e Tλ B =2n e T

[0108] Δλ B =2Δn e T+2n e ΔT

[0109]

[0110] In the formula, λ B n is the resonant wavelength of the fiber optic grating. e λ is the effective refractive index of the fiber grating propagation mode; T is the grating period; ε is the test strain value; λ is the output wavelength; λ0 is the initial wavelength; K b The strain coefficient;

[0111] The two measuring points 7 at the front and rear of the fiber optic grating FRP-OF smart stirrup are used to monitor the deformation and longitudinal resistance capacity of the sleeper box after being severely damaged by foreign object intrusion, as well as the damage to the side of the sleeper; the measuring point 8 on the bottom surface is used to monitor the longitudinal and transverse resistance capacity of the bottom track bed-ballast-sleep, as well as the bending moment and damage inside the sleeper.

[0112] The advantages of the fiber optic grating FRP-OF vibration sensor 3 and the fiber optic grating FRP-OF smart stirrup 7 are: they are not affected by the complex chemical reaction environment during the concrete hydration process, have good insulation, strong heat resistance, good corrosion resistance, and strong anti-electromagnetic interference ability; the test accuracy and test range meet the monitoring requirements under various extreme conditions in various parts of China.

[0113] The foreign object positioning module includes an environmental sensor 5 and a radar 6. The environmental sensor 5 and radar 6 are placed on the 5G demodulation alarm device 4 along the transverse direction of the sleeper and are connected to the 5G demodulation alarm device 4.

[0114] Radar 6 combines the multi-scale characteristic analysis of microseismic signals with the upper structure of the foreign object monitoring module, utilizes the propagation characteristics of seismic waves and receives its own electromagnetic waves, and combines active and passive positioning methods to accurately and quickly determine the location and coverage area of ​​foreign objects, ensuring no blind spots in detection.

[0115] The radar 6, combined with the upper structure of the foreign object monitoring module, can further subdivide the vibration caused by foreign object intrusion into rail vibration, sleeper vibration, and ballast vibration based on the initial location of the foreign object. Because the different initial locations of the foreign object intrusion trigger different micro-vibration signals, the damage to ballasted track varies. Through frequency domain analysis, the complex signals caused by various external factors such as the monitoring environment and system noise can be simplified. Information such as the signal strength of different frequencies contained in a signal can be extracted and analyzed as needed.

[0116] Radar 6, combined with the upper structure of the foreign object monitoring module, integrates relevant parameters of foreign object intrusion events with the line mileage and inspection and maintenance records of the past 180 days, packages them together, and returns them to the lower structure of the foreign object monitoring module to determine the damage to the ballasted track.

[0117] The environmental sensor 5 integrates multiple devices and functions, including a rain sensor, a wind speed sensor, a seismic detector, and a train sensor, to monitor the environmental and weather impacts under the influence of multiple factors such as wind speed, rainfall, snowfall, and earthquakes, as well as the impacts of external factors such as train operation, track maintenance work, and animal encroachment.

[0118] Environmental sensor 5 measures natural phenomena such as rainfall and snowfall, wind speed, and the intensity of earthquakes. In the event of a foreign object intrusion, it rapidly generates an environmental and weather dataset to assess the impact of the environment and weather on the current intrusion and predict various possibilities regarding future impacts, including the extent of damage to the ballast track.

[0119] Environmental sensor 5 has the function of monitoring influencing factors such as train operation, track maintenance work, and animal encroachment. The collected data is processed to form a preliminary factor dataset. If no foreign object encroachment event occurs, it is treated as a normal factor and stored by the foreign object alarm module to improve the monitoring accuracy of the foreign object location module and avoid false alarms. If a foreign object encroachment event occurs, the preliminary factor dataset is combined with the environmental weather dataset and transmitted to the 5G demodulation alarm device 4 to realize the comprehensive judgment of foreign object alarm information and assist the 5G demodulation alarm device 4 in determining the alarm type.

[0120] The foreign object alarm module consists of a 5G demodulation alarm unit 4. It can simultaneously receive output signals and datasets from various modules of different types, combining the aforementioned monitoring parameters. It can load data files of several gigabytes in size within a short time, quickly completing data aggregation and analysis. This enables the identification of the causes of vibration events on railways, such as vibrations caused by foreign object intrusion, vibrations caused by landslides, and vibrations caused by trains, forming a graded alarm mechanism for foreign object intrusion.

[0121] The 5G demodulation alarm device 4 simultaneously connects to a satellite to take high-definition photos of the location where the foreign object intrusion incident occurs. If there are active and passive protection nets, video capture devices, and other external environmental monitoring equipment at the ballast track, it can also connect to the active and passive protection nets to carry out data sharing and analysis, and require the video capture device to capture video images of the scene of the foreign object intrusion incident on the ballast track, analyze the image content, and form a corresponding maintenance plan;

[0122] The maintenance plan is divided into a temporary emergency repair plan and a major overhaul plan. It pre-plans temporary emergency repair measures after the occurrence of foreign object intrusion incidents and overall maintenance measures after line damage. It also suggests that the number of maintenance personnel required, the types of tools required, the line mileage, and the inspection and maintenance records of the past 180 days be transmitted to the track maintenance section's big data application window via SMS, GPRS, etc.

[0123] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for monitoring foreign object intrusion and damage to ballasted track, applied to an intelligent sleeper used for monitoring foreign object intrusion and damage to ballasted track, characterized in that, The intelligent sleeper includes a ballasted track sleeper (1) and a foreign object intrusion device, wherein the foreign object intrusion device is divided into a foreign object monitoring module, a foreign object positioning module and a foreign object alarm module; The foreign object intrusion device is installed at the top center of the ballast track sleeper (1); The foreign object monitoring module is installed at the bottom of the foreign object alarm module, and the foreign object positioning module is installed on the upper surface of the foreign object alarm module. The modules communicate with each other. The foreign object monitoring module is used to monitor the micro-vibration signal generated by the impact of foreign objects at the landing point, obtain foreign object intrusion limit parameters, and analyze the foreign object intrusion limit parameters; The foreign object positioning module is used to monitor the influence of environmental and external factors on the ballast track sleeper (1) and determine the location and coverage area of ​​the foreign object intrusion. The foreign object alarm module is used to receive data from the foreign object monitoring module and the foreign object positioning module, take pictures of the foreign object intrusion site, form a corresponding maintenance plan, and send an alarm to the engineering section's big data department. The monitoring method includes the following steps: S1. The foreign object monitoring module monitors the micro-vibration signal generated by the impact of a foreign object on the landing point. By analyzing the signal, it judges the change of the foreign object intrusion limit parameter and transmits the data to the foreign object alarm module and the foreign object positioning module. S2. The foreign object location module monitors the influence of environmental and external factors, uses the propagation characteristics of vibration waves and receives its own electromagnetic waves to determine the location and coverage area of ​​the foreign object intrusion, and transmits the data to the foreign object monitoring module and the foreign object alarm module. S3. The foreign object monitoring module determines the damage status of the ballasted track and transmits the determination result to the foreign object alarm module. S4. The foreign object alarm module combines the data transmitted by the foreign object monitoring module and the foreign object positioning module to complete the data collection and analysis, and takes photos or videos of the foreign object intrusion incident site to establish a corresponding maintenance plan. S5, the foreign object alarm module transmits the corresponding maintenance plan to the track maintenance section's big data application window.

2. The method for monitoring foreign object intrusion and ballast track damage according to claim 1, characterized in that, The ballasted track sleeper (1) has spiral ribs (2) on both sides of the shoulder, and a mounting groove for installing a foreign object intrusion device is provided at the top middle position. A protective shell is installed on the mounting groove. The protective shell has reserved holes for connecting the foreign object monitoring module along the longitudinal direction of the ballasted track sleeper (1). The foreign object monitoring module, foreign object alarm module and foreign object positioning module are installed laterally along the ballasted track sleeper (1) and stacked from bottom to top before being placed in the protective shell and fixedly installed in the mounting groove.

3. The method for monitoring foreign object intrusion and ballast track damage according to claim 1, characterized in that, The foreign object monitoring module includes a fiber Bragg grating FRP-OF vibration sensor (3) and a fiber Bragg grating FRP-OF smart stirrup (7). The fiber Bragg grating FRP-OF vibration sensor (3) is fitted with a fiber Bragg grating FRP-OF smart stirrup (7). The fiber Bragg grating FRP-OF vibration sensor (3) is connected to the bottom of the foreign object alarm module. The fiber Bragg grating FRP-OF vibration sensor (3) is a displacement sensor, velocity sensor or acceleration sensor.

4. The method for monitoring foreign object intrusion and ballast track damage according to claim 3, characterized in that, Vibration-strain measuring points (8) are set at the middle positions of the front, rear and bottom of the fiber optic grating FRP-OF smart stirrup (7). The vibration-strain measuring points (8) at the front and rear monitor the deformation and longitudinal resistance capacity of the sleeper box after being severely damaged by foreign object intrusion, as well as the damage to the side of the sleeper. The vibration-strain measuring points (8) at the bottom monitor the longitudinal and transverse resistance capacity of the bottom track bed, ballast and sleeper, as well as the bending moment and damage inside the sleeper.

5. The method for monitoring foreign object intrusion and damage to ballast track according to claim 1, characterized in that, The foreign object location module includes an environmental sensor (5) and a radar (6). The environmental sensor (5) and the radar (6) are installed on the surface of the foreign object alarm module. The environmental sensor (5) has a built-in rain sensor, wind speed sensor, earthquake detector and train sensor.

6. The method for monitoring foreign object intrusion and ballast track damage according to claim 1, characterized in that, The foreign object alarm module includes a demodulation alarm (4) and an external docking device.

7. The method for monitoring foreign object intrusion and ballast track damage according to claim 1, characterized in that, The foreign object monitoring module is equipped with a fiber Bragg grating FRP-OF vibration sensor (3) and a fiber Bragg grating FRP-OF smart stirrup (7). When a foreign object intrusion event occurs, the fiber Bragg grating FRP-OF vibration sensor (3) monitors the micro-vibration signal generated by the impact of the foreign object on the landing point, and analyzes it based on the endpoint detection method of short-time energy of the signal, including: foreign object intrusion time, vibration duration, vibration frequency, attenuation coefficient and waveform correlation coefficient. The fiber Bragg grating FRP-OF vibration sensor (3) converts the effective data signal into the mass, volume, quantity and energy parameters of the foreign object, classifies the foreign object intrusion vibration event into four types: single foreign object intrusion vibration, foreign object intrusion bouncing vibration, multiple foreign object intrusion vibration and collapse vibration, and performs frame processing by determining the frame length and frame shift data, sets an appropriate energy threshold, and then calculates the short-time energy of each frame. The calculation method of short-time energy is as follows: let the signal of the m-th frame after frame division be x. m The short-time energy of {x(i)} (i = 1, 2, ..., N) is E. m Let N represent the length of each frame of signal, then: The signal time series is processed into numbers between [-1, 1] using the mapminmax function. Assume the data x = [x1, x2, ..., x...]. n ], y = [y1, y2, ..., y n ], and y = mapminmax(x), then we have: Among them, y max =1, y min =-1, substituting it in, we get: Each frame of data is detected one by one using a pre-set energy threshold. If the threshold is exceeded, the frame of data is calibrated as the endpoint of the valid data signal, and then the valid data segment is finally determined for subsequent data processing and calculation. The fiber vibration or pressure of the fiber optic grating FRP-OF smart hoop (7) acts on the sensing optical cable, causing changes in the fiber core diameter, fiber core refractive index, and fiber length. These changes alter the phase of the transmitted light in the sensing optical cable, which is then converted into a fiber vibration signal carrying external behavioral information after photoelectric conversion. When the foreign object monitoring module meets the phase matching condition, the fiber harmonic array wavelength, grating resonant wavelength offset, and strain change relationship are calculated using the following formula: l B =2n e T, l B =2n e T, Dl B =2Δn e T+2n e ΔT, In the formula, λ B n is the resonant wavelength of the fiber optic grating. e λ is the effective refractive index of the fiber grating propagation mode; T is the grating period; ε is the test strain value; λ is the output wavelength; λ0 is the initial wavelength; K b is the strain coefficient.

8. The method for monitoring foreign object intrusion and ballast track damage according to claim 1, characterized in that, The foreign object location module is equipped with an environmental sensor (5) and a radar (6). The environmental sensor (5) generates an environmental weather dataset to determine the degree of influence of the environment and weather on foreign object intrusion events and predict the degree of damage to the ballast track. For external factors, including the impact of train operation, track maintenance personnel's maintenance work and animal intrusion, the environmental sensor (5) acquires data and processes it to form a preliminary factor dataset. If no foreign object intrusion event occurs, it is stored as a normal factor in the foreign object alarm module. If a foreign object intrusion event occurs, the preliminary factor dataset is combined with the environmental weather dataset and transmitted to the foreign object alarm module to assist the foreign object alarm module in determining the alarm type. According to the different initial foreign object intrusion positions, the radar (6) divides the foreign object intrusion vibration into rail vibration, sleeper vibration and ballast vibration. Because the different initial foreign object intrusion positions cause different micro-vibration signals, the complex signals caused by external factors are simplified by frequency domain analysis. According to the requirements, the signal strength information of different frequencies contained in a signal is extracted for analysis. By combining the foreign object monitoring module, the propagation characteristics of vibration waves and the electromagnetic waves emitted by the receiver are used to determine the foreign object intrusion position and coverage area by combining active and passive positioning methods.

9. The method for monitoring foreign object intrusion and ballast track damage according to claim 1, characterized in that, The foreign object alarm module is equipped with a demodulation alarm device (4) and an external connection device. The demodulation alarm device (4) has 5G technology support function. Combined with the parameters monitored by the foreign object monitoring module and the foreign object positioning module, it synchronously receives the output signals and datasets of various devices and different unit types to realize the identification and analysis of the causes of foreign object vibration events, including vibration caused by foreign object intrusion, vibration caused by collapse and vibration caused by train, forming a graded alarm mechanism for foreign object intrusion. At the same time, it connects to the external docking device to take high-definition pictures of the location where a foreign object intrusion event occurs on the ballasted track, forming a maintenance plan, including the number of maintenance personnel and the basic parameters of the types of tools required. All of these are transmitted to the engineering section's big data application window in the form of SMS and GPRS. The external docking device includes satellite and active and passive protection nets.

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