An inspection device and method for track damage based on a flexible thin-film pressure sensor

Abstract

The present invention discloses an inspection device and method for track damage based on a flexible thin-film pressure sensor, which relates to the field of track damage detection. The inspection device includes a mounting seat and a detection device; the detection device includes a pressure sensing module and a support module; the support module and the mounting seat ensure the stable operation of the device on the railway track; the pressure detection device in the pressure sensing module is responsible for detecting track damage. Among them, the nylon bristles on the flexible thin-film pressure sensor wrap and press the railway track from three directions in all-round way and transmit the pressure information and changes back in the form of a function. When there is no obvious damage or foreign object on the track surface, the function value is within the error range. When there is damage or foreign object on the track, the function fluctuates. By performing double integral and triple integral on the function value, the area of the concave or convex area under the track surface and the volume of the concave or convex area can be obtained, so as to achieve the purpose of detecting the track damage state.

Description

Technical Field

[0001] The present invention relates to the field of track damage detection, and particularly to a track damage inspection device and method based on a flexible thin-film pressure sensor. Background Art

[0002] Rail inspection devices are used to monitor and evaluate the status of railway tracks, aiming to ensure the safe operation of railways. There are three main inspection methods in the process of railway track maintenance, including heavy inspection vehicle inspection, small double-track detection equipment inspection, and manual single-track detection. The diversified development of rail inspection devices not only improves the efficiency and accuracy of rail inspection but also provides a solid guarantee for railway safety.

[0003] Within the scope of existing technologies, the traditional method of manual inspection is often used, which includes two modes: walking inspection and riding inspection. In the walking inspection mode, inspectors use inspection tools such as inspection hammers to gradually check and determine the damage condition of the railway track. This method has obvious deficiencies, specifically manifested as poor inspection efficiency, limited railway track intervals that can be covered in a single inspection, and high labor intensity of inspectors. In the riding inspection mode, inspectors observe the damage situation of the railway track while riding on a running train. This mode highly relies on the observation ability of inspectors, and in practical applications, its detection accuracy and precision are at a relatively low level.

[0004] Chinese Patent CN104535652A discloses a method for detecting rail damage, which processes the real-time image of the rail using an image detection device and performs ultrasonic detection on the rail using an ultrasonic detection device, and determines the damage degree of the rail based on the processing results of the two, and can identify discrete defects and corrugation defects of the track; moreover, the use of automatic equipment reduces the labor cost.

[0005] Chinese Patent CN205301239U discloses a non-destructive detection device for rail defects, which can confirm the existence of defects or damages and determine the positions of the defects and damages by measuring the static magnetic force generated by a permanent magnet, but cannot determine the detailed information of the damages or defects.

[0006] Currently, there is a need for a non-destructive rail inspection and detection device that can reduce labor costs and accurately determine the position and detailed information of rail defects or damages. Summary of the Invention

[0007] The problem to be solved by the present invention is how to propose a more convenient, efficient and accurate method for detecting track damage.

[0008] To solve the above problems, the present invention proposes the following solutions:

[0009] An inspection device for track damage based on a flexible film pressure sensor. The key technology lies in that the device includes a mounting seat and a detection device. The mounting seat is of a portal structure and is used to connect the inspection vehicle and carry the detection device, and the detection device is installed inside the mounting seat. The detection device includes a pressure sensing module and a support module.

[0010] The support module includes a cross beam, track clamping plates installed on the cross beam, and a control rod for controlling the distance between the clamping plates. The track clamping plates include sleeves, straight plates, arc plates, and clamping plate bodies. The sleeves are sleeved on the cross beam, the straight plates are connected below the sleeves, and the arc plates are connected to the other ends of the sleeves and the straight plates to strengthen the structural stability. The connection between the arc plate and the straight plate is connected to the clamping plate body. The control rod includes a straight rod and a connecting piece, and the straight rod is respectively connected to two sleeves through the connecting piece.

[0011] The pressure sensing module includes a fixed block, a wire routing box, a pressure detection device, and a guiding device. The pressure detection device includes a three-sided frame, nylon bristles, and a flexible film pressure sensor. The fixed block is sleeved in the middle of the cross beam and is connected to the wire routing box below. The wire routing box is connected to the three-sided frame below. The flexible film pressure sensor is arranged on the inner surface of the three-sided frame. The nylon bristles are arranged in a matrix and fixed on the surface of the flexible film pressure sensor. The guiding device includes a pair of pulleys arranged on the fixed block and connected by thin rods, two pairs of small pulleys arranged on the outer surfaces of both sides of the three-sided frame and connected by thin rods, and a crawler transmission component. The crawler transmission component includes two groups of crawlers, which are connected between the clamping plates and the railway tracks through thin rods.

[0012] The pressure detection device is used to detect track damage, and the nylon bristles are used to transfer the pressure generated by the contact between the track and the device to the flexible film pressure sensor.

[0013] The flexible film pressure sensor is used to collect the pressure transmitted by the nylon bristles and transmit the pressure signal to a computer. The computer calculates the area and volume of the track damage through the change amplitude of the pressure signal.

[0014] The data port of the flexible film pressure sensor is connected to the signal receiving device in the inspection vehicle through the wire routing box; the power port of the flexible film pressure sensor is connected to the power supply in the inspection vehicle through the wire routing box.

[0015] The diameters of the pulleys and small pulleys are selected according to the length of the nylon bristles. The diameters of the pulleys and small pulleys are slightly smaller than the length of the nylon bristles to ensure the detection sensitivity of the nylon bristles to track damage. The pulleys and small pulleys slide on the corresponding surfaces of the track.

[0016] A method for inspecting track damage based on a flexible thin-film pressure sensor, which is completed by means of the track damage inspection device described in any one of claims 1-5. It is characterized by including the following steps:

[0017] 1) Detect whether the device is running;

[0018] 2) After the device is turned on, the flexible thin-film pressure sensor receives the pressure signal through nylon bristles and transmits it to the computer;

[0019] 3) When the received pressure signal fluctuates, the computer calculates the area at the fluctuating point and simultaneously controls the inspection vehicle to drive over again at a slower speed;

[0020] 4) After driving over again to obtain more accurate data, the computer uses the more accurate data to calculate the volume at the fluctuating point and outputs the position, area, volume, and morphological information of the track defect;

[0021] 5) The device continues to run and the inspection vehicle continues to move forward.

[0022] The computer displays the pressure coefficient in the form of a function, which is specifically the product of the stress of the nylon bristles and the cross-sectional area of the nylon bristles; the computer processes the data at the fluctuating point of the function and calculates the area and volume at the fluctuating point.

[0023] The advantages of adopting the technical solution are as follows:

[0024] In the present invention, nylon bristles are used to contact the track, and the pressure between the nylon bristles and the track is transmitted to the flexible thin-film pressure sensor. The accurate pressure perception and transmission perception mechanism provides a data basis for accurate damage judgment. Moreover, due to the adjustable length of the nylon bristles, different track environments can be adapted, improving universality.

[0025] The present invention uses an automated device to replace manual inspection. The nylon bristles always follow the inspection vehicle to sense the pressure of the track and can continue to run without stopping before the pressure fluctuates, avoiding frequent stops and human intervention, thereby improving the inspection efficiency.

[0026] The present invention uses pressure perception to determine track damage, and can quickly and accurately judge whether the damage type is a protrusion or a depression through the change of pressure, providing a data basis for subsequent maintenance and reducing the time for the overall inspection and maintenance process.

[0027] The present invention uses a computer to calculate the area and volume of the damaged part, providing accurate data for subsequent maintenance and repair, which is helpful for formulating repair plans. Moreover, by long-term accumulation and analysis of these data trends, data support can be provided for track maintenance and adjustment of train operation plans. Description of the Drawings

[0028] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] Figure 1 Schematic diagram of the inspection method for detecting track damage based on a flexible thin-film pressure sensor proposed by the present invention;

[0030] Figure 2 Overall schematic diagram of the inspection device for detecting track damage based on a flexible thin-film pressure sensor proposed by the present invention;

[0031] Figure 3 is Figure 2 Partial enlarged view of part A in

[0032] Figure 4 Schematic diagram of the inspection device for detecting track damage based on a flexible thin-film pressure sensor proposed by the present invention after removing the mounting base;

[0033] Figure 5 is Figure 4 Partial enlarged view of part B in

[0034] Figure 6 Schematic diagram of the pressure detection module in the inspection device for detecting track damage based on a flexible thin-film pressure sensor proposed by the present invention;

[0035] Figure 7 Two-dimensional image formed by the pressure change when the flexible thin-film pressure sensor in the inspection device proposed by the present invention encounters a protrusion;

[0036] Figure 8 Two-dimensional image formed by the pressure change when the flexible thin-film pressure sensor in the inspection device proposed by the present invention encounters a depression;

[0037] Figure 9 Three-dimensional image formed by the pressure change when the flexible thin-film pressure sensor in the inspection device proposed by the present invention encounters a protrusion;

[0038] Explanation of reference numerals

[0039] 1. Mounting base; 2. Support module; 21. Cross beam; 22. Rail splint; 221. Sleeve; 222. Straight plate; 223. Arc plate; 224. Splint main body; 23. Control rod; 231. Straight rod; 232. Connecting piece; 3. Pressure sensing module; 31. Fixed block; 32. Wiring box; 33. Pressure detection device; 331. Three-sided frame; 332. Nylon brush; 333. Flexible thin-film pressure sensor; 34. Guiding device; 341. Pulley; 342. Small pulley; 343. Track drive device. Specific embodiments

[0040] To make the features and advantages of the present invention more obvious and understandable, the following will clearly and completely describe the technical solution in combination with the drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all embodiments.

[0041] An embodiment of the present invention discloses a track damage inspection device and method based on a flexible thin-film pressure sensor, including the following steps:

[0042] As Figures 2-6 shown, this device includes a mounting base 1 and a detection device; the detection device includes a pressure sensing module 3 and a support module 2; the pressure sensing module 3 includes a fixed block 31, a wire routing box 32, a pressure detection device 33, and a guiding device 34; the fixed block 31 is sleeved in the middle of the cross beam 21 and is connected to the wire routing box 32 below. The wire routing box 32 is connected to a three-sided frame 331 below. A flexible thin-film pressure sensor 333 is arranged on the inner surface of the three-sided frame 331, and nylon bristles 332 are arranged in a matrix and fixed on the surface of the flexible thin-film pressure sensor 333; the guiding device 34 includes a pair of pulleys 341 arranged on the fixed block 31 and connected by thin rods, two pairs of small pulleys 342 arranged on the outer surfaces of both sides of the three-sided frame 331 and connected by thin rods, and a crawler drive assembly 343; the crawler drive assembly 343 includes two groups of crawlers, which are connected between the splints and the railway tracks by thin rods.

[0043] The nylon bristles 332 play a role in connecting the flexible thin-film pressure sensor 333 to the track surface, establishing a close and effective contact relationship between the sensor and the track; in this embodiment, they are arranged in a matrix and fixed on the surface of the flexible thin-film pressure sensor 333, and are respectively fixed in the pores of a hard pore plate. When the nylon bristles 332 are squeezed, the corresponding area of the flexible thin-film pressure sensor 333 will generate a change in the pressure signal, which is converted into a change in the electrical signal, and then transmitted to the computer to convey the pressure information.

[0044] The flexible thin-film pressure sensor 333 is a device that realizes detection based on the change of its own electrical and other properties when subjected to external pressure. When external pressure acts on the flexible thin-film pressure sensor 333, the electrical and other properties of its sensitive material change accordingly, generating a corresponding electrical signal. This signal is processed through circuit amplification, conversion, etc., and finally converted into recognizable data, so as to realize the functions of perceiving, monitoring, and feedback of specific physical quantities.

[0045] The flexible film pressure sensor 333, as the core sensing part of the entire detection system, has the characteristic of high sensitivity and can accurately sense the change of pressure. The flexible film pressure sensor 333 collects the pressure transmitted by the nylon bristles 332 and transmits the pressure signal to the computer. The computer calculates the area and volume of the track damage through the change amplitude of the pressure signal. In this embodiment, the flexible film pressure sensor 333 has two ports: a power port and a signal port, which are respectively connected to the signal receiving device and the power supply in the inspection vehicle. The power port of the flexible film pressure sensor 333 is divided into a power input terminal and a ground terminal. The power input terminal is connected to the positive pole of the power supply to provide the power supply voltage required by the sensor. The ground terminal is connected to the negative pole of the power supply to provide the circuit loop. The signal terminal of the flexible film pressure sensor 333 emits an output signal, which carries the information of the pressure or force received, that is, an analog voltage signal. This signal is connected to the analog input channel or data acquisition card in the signal receiving device in the inspection vehicle.

[0046] When the track has a concave damage, the sensor pressure decreases; when the track has a convex damage or there is a foreign object on the track, the sensor pressure increases.

[0047] The guiding device 34 is responsible for the more stable operation of the inspection device on the railway track. The cooperation of the pulley 341, the small pulley 342 and the crawler drive assembly 343 ensures that the device fits the track for operation.

[0048] The diameters of the pulley 341 and the small pulley 342 correspond to the lengths of the corresponding nylon bristles 332, and the diameters of the pulley 341 and the small pulley 342 are slightly smaller than the lengths of the nylon bristles 332. The pulley 341 and the small pulley 342 slide on the corresponding surfaces of the track.

[0049] The crawler drive assembly 343 provides stable operating conditions for the inspection vehicle in the operation mechanism of the inspection vehicle, ensuring that it can travel smoothly along the railway track. The transmission between the track clip 22 and the I-shaped railway track is realized through the crawler. The crawler drive assembly 343 is used for guiding between the track clip 22 and the I-shaped railway track. The two crawlers are symmetrically distributed at the gap between the track clip 22 and the side of the railway track.

[0050] The support module 2 includes a cross beam 21, a track clip 22 installed on the cross beam 21, a control rod 23 for controlling the clip spacing, and a crawler drive assembly 343. The track clip 22 includes a sleeve 221, a straight plate 222, an arc plate 223 and a clip main body 224. The sleeve 221 is sleeved on the cross beam 21. The straight plate 222 is connected below the sleeve 221. The arc plate 223 is connected to the other ends of the sleeve 221 and the straight plate 222 to strengthen the structural stability. The control rod 23 is respectively connected to the two sleeves 221 through the connecting piece 232.

[0051] The support module 2 provides support for the entire detection process and ensures its normal operation. The inspection vehicle equipped with the inspection device has stable operating performance and a reasonable structural design, and can run smoothly along the railway track, thereby driving the entire inspection device to complete the comprehensive inspection of the track.

[0052] The straight rod 231 in the control rod 23 is connected to the sleeve 221 on the rail splint 22 through the connecting piece 232. By rotating the straight rod 231, the sleeve 221 is driven to move, assisting the rail splint 232 to approach the track, so that the crawler drive assembly 343 in the guiding device 34 is closely attached to the track.

[0053] As Figure 1 shown, when the inspection vehicle runs normally along the established route above the railway track, the nylon bristles 332 are arranged in a matrix and fixed on the surface of the flexible film pressure sensor 333. Each nylon bristle 332 has a corresponding position on the sensor (represented by coordinates (Xn, Yn)). When the bristle contacts the railway track and is squeezed and bent due to the running of the inspection vehicle, it will generate pressure on the flexible film pressure sensor 333.

[0054] In the operating state, some data change. For example, the nylon bristle has a cross-sectional area A, elastic modulus E, original length L, and change length ΔL. The change length and the original length can characterize the strain of the nylon bristle 332. The elastic modulus and strain of the bristle can further characterize the stress of the bristle. Finally, the elastic force of the bristle, that is, the pressure on the sensor, is calculated through the stress and the cross-sectional area of the bristle; when the track is normal, the nylon bristle 332 is in a normal state; as Figures 7-8 shown, when the track has a concave damage, the bristle will elongate, and its change length ΔL becomes smaller. Correspondingly, the pressure (elastic force F) generated on the sensor will also decrease; when the track has a protruding damage or there is a foreign object, the bristle will be further compressed, ΔL increases, and the pressure (elastic force F) on the sensor increases.

[0055] The change of the nylon bristle 332 can sensitively detect the pressure condition borne by the railway track, and can also transmit the information related to the pressure and the dynamic change condition of the pressure back to the data processing system in an accurate function manner in real time.

[0056] As Figure 9As shown, when there are fluctuations in the pressure signal, the flexible film pressure sensor 333 will transmit the signal to the computer. The computer relies on pre-set algorithms and models, and at the same time combines geometric parameters such as the shape and size of the track and factors such as the installation position of the sensor to carefully and deeply analyze the received pressure signal. The purpose is to accurately calculate the size (area and volume) of the protruding or concave parts on the track surface, so as to provide a strong basis for evaluating the degree of track damage. The specific operation is as follows: First, set the maximum pressure Fmax and the minimum pressure Fmin for each bristle. This is the normal range of pressure changes when walking on a normal railway track. When the pressure F sensed by the flexible film pressure sensor 333 exceeds this normal range (greater than Fmax or less than Fmin), record the position (Xn, Yn) of the bristle at this time. After the inspection vehicle has passed through the track damage area, through these recorded (Xn, Yn) data sets, (X0, Y0) represents the starting position of the damage, and (X1, Y1) represents the ending position of the damage. The integral from the starting position to the ending position is used to characterize the area of the damaged part.

[0057] For a specific area with pressure signal fluctuations, the inspection vehicle will drive through this area again at a relatively slow and stable speed. Through re-measurement, more precise data information in this area is collected in more detail, especially obtaining a more accurate change length ΔL. Similarly, (X0, Y0) is the initial position of the damage, and (X1, Y1) is the final position of the damage. The triple integral of the starting position, ending position, and change length is used to characterize the damage volume. Based on these more detailed data, the volume V of the fluctuating area part is calculated. The calculated value of the volume V will be more accurate and reliable; in specific use: The computer calculates according to the formula:

[0058] Strain

[0059] Stress σ = E × ε

[0060] That is, under normal circumstances

[0061] Elastic force F = σ × A

[0062] Through the pressure data received by the flexible film pressure sensor 333, after data processing and calculation, combined with the specific parameters of the track and the installation position of the sensor, the position of the protruding or concave defect on the track surface is obtained. The area of the defect is calculated through the formula:

[0063]

[0064] Combined with the collected pressure information, the final area of the track damage is obtained as:

[0065]

[0066] Similarly, according to the formula:

[0067] That is

[0068] Calculate the volume at the defect, combine with the pressure signal, and finally the volume of the track damage obtained is:

[0069]

[0070] After completing the above operations, if there is no fluctuation in the pressure signal, the detection device will continue the subsequent inspection work according to the predetermined inspection plan and the established operation track.

Claims

1. An inspection device for track damage based on a flexible film pressure sensor, characterized in that, The device includes a mounting base (1) and a detection device; wherein the mounting base (1) is of a portal structure for connecting the inspection vehicle and carrying the detection device, and the detection device is installed inside the mounting base (1); the detection device includes a pressure sensing module (3) and a support module (2); The support module (2) includes a cross beam (21), rail clamping plates (22) installed on the cross beam (21), and a control rod (23) for controlling the distance between the clamping plates; the rail clamping plates (22) include sleeves (221), straight plates (222), arc plates (223), and clamping plate bodies (224); the sleeves (221) are sleeved on the cross beam (21), the straight plates (222) are connected below the sleeves (221), and the arc plates (223) are connected to the other ends of the sleeves (221) and the straight plates (222) to enhance the structural stability; the connection between the arc plates (223) and the straight plates (222) is connected to the clamping plate body (224); the control rod (23) includes a straight rod (231) and a connecting member (232), and the straight rod (231) is connected to the two sleeves (221) respectively through the connecting member (232); The pressure sensing module (3) includes a fixed block (31), a wire routing box (32), a pressure detection device (33), and a guiding device (34); wherein the pressure detection device (33) includes a three-sided frame (331), nylon bristles (332), and a flexible film pressure sensor (333); the fixed block (31) is sleeved in the middle of the cross beam (21) and is connected to the wire routing box (32) below, the wire routing box (32) is connected to the three-sided frame (331) below, the inner surface of the three-sided frame (331) is provided with the flexible film pressure sensor (333), and the nylon bristles (332) are arranged in a matrix and fixed on the surface of the flexible film pressure sensor (333); the guiding device (34) includes a pair of pulleys (341) connected by thin rods arranged on the fixed block (31), two pairs of small pulleys (342) connected by thin rods arranged on the outer surfaces of both sides of the three-sided frame (331), and a crawler drive assembly (343); the crawler drive assembly (343) includes two groups of crawlers, which are connected between the clamping plates and the rails by thin rods.

2. The track damage inspection device based on a flexible film pressure sensor according to claim 1, wherein The pressure detection device (33) is used to detect rail damage, and the nylon bristles (332) are used to transfer the pressure generated by the contact between the rail and the device to the flexible film pressure sensor (333).

3. The track damage inspection device based on a flexible thin-film pressure sensor according to claim 1, characterized in that, The flexible film pressure sensor (333) is used to collect the pressure transferred by the nylon bristles (332) and transmit the pressure signal to a computer, and the computer calculates the area and volume of the rail damage through the change amplitude of the pressure signal.

4. The track damage inspection device based on a flexible thin-film pressure sensor according to claim 1, characterized in that, The data port of the flexible film pressure sensor (333) is connected to the signal receiving device in the inspection vehicle through the wire routing box (32); the power port of the flexible film pressure sensor (333) is connected to the power supply in the inspection vehicle through the wire routing box (32).

5. The track damage inspection device based on a flexible thin-film pressure sensor according to claim 1, characterized in that, The diameters of the pulley (341) and the small pulley (342) are selected according to the length of the nylon bristles (332). The diameters of the pulley (341) and the small pulley (342) are slightly smaller than the length of the nylon bristles (332) to ensure the detection sensitivity of the nylon bristles (332) to track damage. The pulley (341) and the small pulley (342) slide on the corresponding surfaces of the track.

6. A method for inspecting track damage based on a flexible thin-film pressure sensor, the method being completed by means of the track damage inspection device according to any one of claims 1-5, characterized in that, It includes the following steps: 1) Detect whether the detection device is running; 2) After the device is turned on, the flexible film pressure sensor (333) receives the pressure signal through the nylon bristles (332) and transmits it to the computer; 3) When the received pressure signal fluctuates, the computer calculates the area at the fluctuating point and simultaneously controls the inspection vehicle to drive over again at a slower speed; 4) After driving over again to obtain more accurate data, the computer uses the more accurate data to calculate the volume at the fluctuating point and outputs the position, area, volume and morphological information of the track defect; 5) The device continues to run and the inspection vehicle continues to move forward.

7. A method for inspecting track damage based on a flexible thin-film pressure sensor according to claim 6, characterized in that, The computer displays the pressure coefficient in the form of a function, specifically expressed as the product of the stress of the nylon bristles (332) and the cross-sectional area of the nylon bristles (332); the computer processes the data at the fluctuating point of the function and calculates the area and volume at the fluctuating point.

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