Railway state monitoring system and method based on concave mirror laser reflection displacement amplification

Abstract

The application discloses a track state monitoring system and method based on concave mirror laser reflection displacement amplification, and the system comprises a track state monitoring device and an optical concave mirror, which are composed of a laser transmitter, a laser target, an industrial camera, an NB-IoT module, a microprocessor and a power module. The laser transmitter and the laser target are arranged opposite to the optical concave mirror, and the central axis of the laser transmitter and the central axis of the mirror surface of the optical concave mirror are horizontally arranged on the same vertical plane. The industrial camera is used for capturing laser spot information reflected on the laser target through the optical concave mirror. The microprocessor realizes track state monitoring by machine vision processing and analyzing the laser spot information acquired by the industrial camera. The NB-IoT module uploads the monitored track state to a central server. The effect is that the settlement, inclination and horizontal offset of the track can be effectively and accurately monitored in real time.

Description

Technical Field

[0001] This invention relates to rail transit monitoring technology, and more particularly to a track condition monitoring system and method based on displacement amplification by laser reflection from a concave mirror. Background Technology

[0002] With the acceleration of global urbanization and the dramatic increase in public transportation demand, rail transit, as an efficient, fast, and environmentally friendly transportation solution, has been widely promoted and rapidly developed worldwide. However, the safe operation of rail transit systems faces many challenges, especially as rail lines are affected by numerous internal and external factors during long-term use, such as temperature fluctuations, vehicle weight, infrastructure aging, and geological changes. These factors can lead to changes in track conditions, including vertical and horizontal settlement, horizontal deviation, and tilting, which in severe cases may cause track structural damage, train instability, and even safety accidents.

[0003] Traditional track monitoring methods (mainly including visual inspection and periodic testing) typically have limitations, such as low monitoring accuracy, limited coverage, and insufficient timeliness in responding to sudden conditions. Therefore, developing a high-efficiency monitoring system capable of real-time track status monitoring and rapid response is of great significance for ensuring the safety and operational efficiency of rail transit. Summary of the Invention

[0004] This invention first provides a track condition monitoring system based on concave mirror laser reflection displacement amplification, which mainly solves the problems of limited monitoring range, low monitoring frequency and cumbersome data analysis in existing track condition monitoring methods. By implementing precise adjustment of the laser incident angle on the optical concave mirror, a significant change in the position of the reflected light spot is achieved, thereby effectively monitoring the track settlement, tilt and horizontal offset in real time using "motion amplification" technology.

[0005] To achieve the above objectives, the specific technical solution adopted by the present invention is as follows:

[0006] A track condition monitoring system based on concave mirror laser reflection displacement amplification includes a track condition monitoring device. The device comprises a laser emitter, a laser target, an industrial camera, an NB-IoT module, a microprocessor, and a power module. In use, the track condition monitoring device is positioned at a monitoring point. An optical concave mirror is fixed on the web of the track to be monitored. The laser emitter and the laser target are positioned relative to the optical concave mirror, with the central axis of the laser emitter and the central axis of the mirror surface of the optical concave mirror horizontally aligned on the same vertical plane. The industrial camera captures laser spot information reflected by the optical concave mirror onto the laser target. The microprocessor analyzes the laser spot information acquired by the industrial camera using machine vision to achieve track condition monitoring. The NB-IoT module uploads the monitored track condition to a central server. The power module provides power to all modules.

[0007] Optionally, the track condition monitoring device includes a mounting housing, in which the laser emitter, the industrial camera, the microprocessor, and the NB-IoT module are respectively mounted and fixed inside the mounting housing via their respective mounting brackets. The mounting housing has a laser penetration window on the side facing the optical concave reflector, and the inner surface of the mounting housing facing the laser penetration window serves as the laser target.

[0008] Optionally, the power module uses a photovoltaic power source and a photovoltaic panel is disposed on the upper surface of the mounting housing.

[0009] Optionally, the industrial camera is mounted directly above the laser emitter and facing inward toward the laser target.

[0010] Optionally, the mounting housing is installed at the monitoring point via a housing mounting bracket.

[0011] Optionally, the distance between the monitoring point and the track to be measured is 5 to 10 meters.

[0012] Optionally, the track status monitored by the microprocessor includes track settlement, track tilt, and track horizontal offset.

[0013] Based on the above system, the present invention also provides a method for monitoring orbital state based on displacement amplification by laser reflection from a concave mirror, comprising the following steps:

[0014] S1: The laser emitter emits a laser beam onto a fixed concave optical mirror on the track web and reflects it onto a laser target. The amount of beam slippage is captured by an industrial camera.

[0015] S2: Determine whether the light spot moves up or down. If it does not move up or down, return to step S1. If it moves down, proceed to step S31. If it moves up, proceed to step S32.

[0016] S31: Determine if the area of ​​the light spot has changed. If it has not changed, proceed as follows:

[0017] Calculate the orbital settlement. ;

[0018] If changes occur, then follow: Calculate the horizontal offset of the track. ;

[0019] S32: According to The formula is used to calculate the track inclination. ;

[0020] S4: Transmit the monitored track status to the central server via the NB-IoT module;

[0021] in: The height difference between the laser optical axis and the central axis of the mirror. Let be the radius of curvature of the concave optical mirror. , These represent the vertical heights of the laser beam landing points after reflection by the concave optical mirrors, before and after track settlement. This refers to the horizontal distance between the laser target and the concave optical mirror. The diameter of the laser spot on the concave optical mirror when the trajectory has not deviated. This represents the area occupied by the laser spot when the trajectory is not deviated. This represents the area occupied by the laser spot after the orbit undergoes a horizontal shift. This represents the initial incident angle of the laser emitter when the orbit is not tilted. The focal length is the distance the laser beam moves in the vertical direction relative to the laser target due to the tilt of the track. satisfy .

[0022] Optionally, the central server can also send SMS notifications to staff based on the track status monitoring results to promptly enter the site for maintenance.

[0023] The significant effects of this invention are:

[0024] This invention provides a track condition monitoring system and method based on concave mirror laser reflection displacement amplification, which can effectively monitor track settlement, tilt, and horizontal offset in real time. The system achieves significant changes in the position of the reflected light spot by precisely adjusting the laser incident angle on an optical concave mirror, thus employing "motion amplification" technology to accurately detect track conditions. Using industrial cameras and machine vision image processing technology, this method can capture minute changes in real time and convert them into quantifiable data through the laser reflection effect. Furthermore, the monitoring device integrates a microprocessor unit, an NB-IoT module, and a solar panel power supply module, giving the system advantages of simple structure and low cost, as well as automated monitoring without manual intervention. This significantly improves monitoring frequency and data processing efficiency, ensuring a high level of safety and stability for the track system.

[0025] The advantages of using the above system and method are as follows: First, it provides highly efficient and accurate track condition monitoring, with track settlement monitoring accuracy reaching 0.05mm, track tilt monitoring accuracy reaching 0.1°, and track horizontal offset monitoring accuracy reaching 0.1m. Furthermore, it can obtain accurate monitoring data in real time to ensure safe train operation. Second, the system is easy to install, flexible to operate, reliable in principle, low in maintenance cost, and environmentally friendly. It can be directly deployed on existing track control networks, facilitating expansion. Third, the system can monitor most track condition risks at key track locations, saving on the number of sensors used, resulting in lower costs and higher efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the installation structure of the track condition monitoring device in an embodiment of the present invention;

[0027] Figure 2 This is a side view of the installation structure of the track condition monitoring device in an embodiment of the present invention;

[0028] Figure 3 This is a layout diagram of an orbital state monitoring system based on concave mirror laser reflection displacement amplification provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the installation position of the optical concave reflector in an embodiment of the present invention;

[0030] Figure 5 A schematic diagram illustrating the process of monitoring track settlement.

[0031] Figure 6 This is a schematic diagram illustrating the process of monitoring track tilt.

[0032] Figure 7 This is a schematic diagram illustrating the process of monitoring horizontal displacement of the track.

[0033] Figure 8 This is a flowchart illustrating a method for monitoring orbital status based on displacement amplification by laser reflection from a concave mirror, as provided in an embodiment of the present invention.

[0034] Reference numerals: 1-track condition monitoring device, 2-optical concave reflector, 11-laser emitter, 12-laser target, 13-industrial camera, 14-NB-IoT module, 15-microprocessor, 16-power module, 17-mounting housing. Detailed Implementation

[0035] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the present invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0036] like Figures 1-4 As shown in the figure, this embodiment provides a track condition monitoring system based on concave mirror laser reflection displacement amplification, including a track condition monitoring device 1 and an optical concave mirror 2. The track condition monitoring device 1 is mounted on the monitoring point via a housing mounting base, and the optical concave mirror 2 is fixed on the rail web of the track to be measured. The distance between the monitoring point and the track to be measured is 5~10m. Figure 1 As can be seen, the track condition monitoring device 1 includes a laser emitter 11, a laser target 12, an industrial camera 13, an NB-IoT module 14, a microprocessor 15, and a power module 16. The laser emitter 11 and the laser target 12 are positioned relative to the optical concave mirror 2, and the central axis of the laser emitter 11 and the central axis of the optical concave mirror 2 are horizontally arranged on the same vertical plane. The laser emitted by the laser emitter 11 is reflected by the optical concave mirror 2 and forms a laser spot on the laser target 12. The industrial camera 13 is used to capture the laser spot information reflected by the optical concave mirror 2 onto the laser target 12. The microprocessor 15 uses machine vision processing to analyze the laser spot information acquired by the industrial camera 13 to realize track condition monitoring. The NB-IoT module 14 uploads the monitored track condition to the central server. The track condition here includes track settlement, track tilt, and track horizontal offset.

[0037] In a specific implementation, the track condition monitoring device 1 also includes a mounting housing 17. The laser emitter 11, the industrial camera 13, the microprocessor 15, and the NB-IoT module 14 are respectively mounted and fixed inside the mounting housing 17 via their respective mounting brackets. The mounting housing 17 has a laser penetration window on the side facing the optical concave reflector 2. Typically, the side of the mounting housing facing the track to be tested is open to facilitate laser penetration. The inner surface of the mounting housing facing the laser penetration window serves as the laser target 12. In order to facilitate the industrial camera to acquire light spot information, in a specific implementation, the industrial camera 13 is mounted directly above the laser emitter 11 and faces inward toward the laser target 12.

[0038] The power module 16 is mainly used to provide power to each module. In order to facilitate power supply in the field, the power module 16 in this example adopts photovoltaic power and a photovoltaic panel is set on the upper surface of the mounting housing 17.

[0039] Based on the above system, the following is combined with Figures 5-7 The measurement principle of the system will be further explained here, without considering the positional limitations between the laser emitter 11 and the laser target 12:

[0040] pass Figure 5 It can be seen that when the track did not settle, the laser beam emitted from point A struck the concave optical mirror. At point A, the laser beam is reflected from the concave optical mirror at an initial reflection angle φ, and the reflected laser spot hits point T on the laser target inside the device. At this time, the vertical distance is h1 (the height difference between the laser axis and the central axis of the mirror). When the track settles, the laser beam emitted from point A hits the concave optical mirror. At the point, the reflection angle becomes accordingly. The reflected laser beam hit the laser target inside the device. At point A, the change in vertical height of the track is as follows: The corresponding change in the laser target hitting the inside of the device is as follows: Due to the effects of sedimentation, the laser reflection angle changes. Based on the known horizontal distance between the laser target and the concave optical mirror... ,like Figure 2 As shown, the vertical displacement of the laser spot can be calculated. Using formula (1):

[0041] (1)

[0042] The initial reflection angle φ can be obtained by formula (2), where φ is the radius of curvature of the concave optical mirror.

[0043] (2)

[0044] Similarly, the reflection angle after settling It can be obtained through formula (2):

[0045] (3)

[0046] Solve using bi-angle and inverse trigonometric function relationships. Will and Substituting the value of into the bi-angle formula and the arcsine relation, we obtain formula (4):

[0047] (4)

[0048] Calculate track settlement Using the known α and other variables in the formula, the solution is obtained by reverse calculation using formula (5). .

[0049] (5)

[0050] The calculated track subsidence The values ​​are transmitted directly to the central server through the monitoring system. Data analysis is used to assess the overall health of the track, including detecting any settlement exceeding safe limits. If a risk warning or alarm is issued, the relevant personnel will be notified via SMS.

[0051] pass Figure 6 It can be seen that before the orbit tilted, the laser beam emitted from point A struck the concave optical mirror. At point 1, the initial incident angle of the laser emitter hitting the concave optical mirror is set to 0. The reflected laser beam hit the laser target inside the device. At point A, even when the track tilts, the laser beam emitted from point A still strikes the concave optical mirror. The point is there, but the angle of incidence changes to... The reflected laser beam hit the laser target inside the device. At the point. Due to the tilt, the focal position of the laser beam after reflection by the concave optical mirror will move in the vertical direction. The longitudinal distance of the laser spot hitting the inner side of the device is defined as... .

[0052] Focal length of an optical concave mirror Due to its radius of curvature The calculation formula (6) is determined as follows:

[0053] (6)

[0054] Using longitudinal displacement and focal length The inclination angle of the track can be calculated using the following formula (7). ;

[0055] (7)

[0056] The calculated track tilt angle The values ​​are transmitted directly to the central server through the monitoring system. Data analysis is used to assess the overall health of the track, including detecting any tilting beyond safe limits. If a risk warning or alarm is issued, the relevant personnel will be notified via SMS.

[0057] pass Figure 7 It can be seen that when the orbit did not deviate horizontally, the laser beam emitted from point A struck the concave optical mirror. At the point, the laser beam is at the initial reflection angle The laser beam reflected from the concave optical mirror strikes the laser target inside the device. At point A, when the trajectory shifted horizontally, the laser beam emitted from point A struck the concave optical mirror. At the point, the angle of reflection is also... The reflected laser beam hit the laser target inside the device. At the point. In the initial state, the laser spot diameter is minimized by adjusting the beam expander of the laser emitter, and its diameter can be described by the following formula (8). :

[0058] (8)

[0059] in, It is the waist of the laser beam. It is the wavelength of the laser. It is the propagation distance between the laser beam and the concave optical mirror.

[0060] When the track deviates horizontally The angle of incidence becomes Due to the horizontal offset, the diameter of the light spot and the receiving position change.

[0061] The horizontal offset of the orbit causes a change in the incident angle, which can be calculated using small angle approximation and geometric relationships, as shown in formula (9):

[0062] (9)

[0063] Considering the small change in angle, it is approximated by formula (10):

[0064] (10)

[0065] The laser spot area reflected by the concave optical mirror is minimized in the initial state, let's call it... After horizontal offset, the spot area increases to The area ratio can be estimated using formula (11):

[0066] (11)

[0067] Based on the above proportional relationship, the horizontal offset can be calculated. Formula (12) is:

[0068] (12)

[0069] The calculated horizontal offset of the track The values ​​are transmitted directly to the central server through the monitoring system. Data analysis is used to assess the overall health of the track, including detecting any horizontal deviations exceeding safe limits. If a risk warning or alarm is issued, the relevant personnel will be notified via SMS.

[0070] From this, we can obtain Figure 8 The method for monitoring orbital state based on displacement amplification by laser reflection from a concave mirror, as shown, includes the following steps:

[0071] S1: The laser emitter emits a laser beam onto a fixed concave optical mirror on the track web and reflects it onto a laser target. The amount of beam slippage is captured by an industrial camera.

[0072] S2: Determine whether the light spot moves up or down. If it does not move up or down, return to step S1. If it moves down, proceed to step S31. If it moves up, proceed to step S32.

[0073] S31: Determine if the area of ​​the light spot has changed. If it has not changed, proceed as follows:

[0074] Calculate the orbital settlement. ;

[0075] If changes occur, then follow: Calculate the horizontal offset of the track. ;

[0076] S32: According to The formula is used to calculate the track inclination. ;

[0077] S4: Transmit the monitored track status to the central server via the NB-IoT module;

[0078] in: The height difference between the laser optical axis and the central axis of the mirror. Let be the radius of curvature of the concave optical mirror. , These represent the vertical heights of the laser beam landing points after reflection by the concave optical mirrors, before and after track settlement. This refers to the horizontal distance between the laser target and the concave optical mirror. The diameter of the laser spot on the concave optical mirror when the trajectory has not deviated. This represents the area occupied by the laser spot when the trajectory is not deviated. This represents the area occupied by the laser spot after the orbit undergoes a horizontal shift. This represents the initial incident angle of the laser emitter when the orbit is not tilted. The focal length is the distance the laser beam moves in the vertical direction relative to the laser target due to the tilt of the track. satisfy .

[0079] As can be seen, this invention utilizes an industrial camera to capture images of the laser beam spot reflected by an optical concave mirror, measuring its longitudinal displacement and area change. If the longitudinal displacement direction of the laser spot is detected to be vertically upward, this indicates that the track has tilted. Based on the longitudinal displacement of the laser spot, the tilt of the track is calculated using a predetermined algorithm. If the longitudinal displacement direction of the laser spot is vertically downward, it is then necessary to detect whether the area of ​​the laser spot has changed. If the area of ​​the spot changes significantly, this usually indicates that the track has shifted horizontally. The horizontal shift is calculated based on the change in the area of ​​the laser spot. As mentioned in the previous steps, if the longitudinal displacement direction of the laser spot is vertically downward and the area has not changed, this usually indicates that the track has settled. In this case, the settlement can be calculated based on the longitudinal displacement of the laser spot.

[0080] Through this advanced monitoring technology, rail transit systems can receive timely warnings and maintenance before encountering potential dangerous conditions, greatly reducing the accident rate and having a positive impact on improving the overall performance of rail transit systems and the passenger experience.

[0081] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A track condition monitoring system based on concave mirror laser reflection displacement amplification, characterized in that, The system includes a track condition monitoring device, comprising a laser emitter, a laser target, an industrial camera, an NB-IoT module, a microprocessor, and a power module. In use, the track condition monitoring device is positioned at a monitoring point. An optical concave reflector is fixed on the web of the track to be monitored. The laser emitter and the laser target are positioned relative to the optical concave reflector, with the central axis of the laser emitter and the central axis of the optical concave reflector horizontally aligned on the same vertical plane. The industrial camera captures laser spot information reflected by the optical concave reflector onto the laser target. The microprocessor uses machine vision to process and analyze the laser spot information acquired by the industrial camera to achieve track condition monitoring. The NB-IoT module uploads the monitored track condition to a central server. The power module provides power to all modules.

2. The track state monitoring system based on concave mirror laser reflection displacement amplification according to claim 1, characterized in that, The track condition monitoring device includes a mounting housing. The laser emitter, the industrial camera, the microprocessor, and the NB-IoT module are respectively mounted and fixed inside the mounting housing via their respective mounting brackets. The mounting housing has a laser penetration window on the side facing the optical concave reflector, and the inner surface of the mounting housing facing the laser penetration window serves as the laser target.

3. The track state monitoring system based on concave mirror laser reflection displacement amplification according to claim 2, characterized in that, The power module uses a photovoltaic power source and a photovoltaic panel is installed on the upper surface of the mounting housing.

4. The track state monitoring system based on concave mirror laser reflection displacement amplification according to claim 2, characterized in that, The industrial camera is mounted directly above the laser emitter and faces inward toward the laser target.

5. The track state monitoring system based on concave mirror laser reflection displacement amplification according to claim 2, 3, or 4, characterized in that, The mounting housing is installed at the monitoring point via a housing mounting bracket.

6. The track state monitoring system based on concave mirror laser reflection displacement amplification according to claim 5, characterized in that, The distance between the monitoring point and the track to be tested is 5~10m.

7. The track condition monitoring system based on concave mirror laser reflection displacement amplification according to claim 1 or 6, characterized in that, The track status monitored by the microprocessor includes track settlement, track tilt, and track horizontal offset.

8. A method for monitoring track status based on displacement amplification by laser reflection using a concave mirror, used in the track status monitoring system according to any one of claims 1-7, characterized in that, The steps include the following: S1: The laser emitter emits a laser beam onto a fixed concave optical mirror on the track web and reflects it onto a laser target. The amount of beam slippage is captured by an industrial camera. S2: Determine whether the light spot moves up or down. If it does not move up or down, return to step S1. If it moves down, proceed to step S31. If it moves up, proceed to step S32. S31: Determine if the area of ​​the light spot has changed. If it has not changed, proceed as follows: Calculate the orbital settlement. ; If changes occur, then follow: Calculate the horizontal offset of the track. ; S32: According to The formula is used to calculate the track inclination. ; S4: Transmit the monitored track status to the central server via the NB-IoT module; in: The height difference between the laser optical axis and the central axis of the mirror. Let be the radius of curvature of the concave optical mirror. , These represent the vertical heights of the laser beam landing points after reflection by the concave optical mirrors, before and after track settlement. This is the horizontal distance between the laser target and the concave optical mirror. The diameter of the laser spot on the concave optical mirror when the trajectory has not deviated. This represents the area occupied by the laser spot when the trajectory is not deviated. This represents the area occupied by the laser spot after the orbit undergoes a horizontal shift. This represents the initial incident angle of the laser emitter when the orbit is not tilted. The focal length is the distance the laser beam moves in the vertical direction relative to the laser target due to the tilt of the track. satisfy .

9. The orbital state monitoring method based on concave mirror laser reflection displacement amplification according to claim 8, characterized in that: The central server also sends SMS notifications to staff based on track status monitoring results, allowing them to promptly enter the site for maintenance.

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