Method for monitoring longitudinal displacement of a point rail

Abstract

The present application relates to a kind of methods for monitoring the longitudinal displacement of switch rail, first, basic rail device and switch rail device are installed on the rail, ensure that magnetostrictive sensor measuring rod passes from the inside of magnetic ring and has no contact;Subsequently, read sensor initial value, when the longitudinal displacement of switch rail occurs, read sensor post-displacement value;Finally, the initial value is subtracted from post-displacement value, combined with the formula derivation of switch rail expansion and contraction amount to derive the change amount of switch rail tip displacement, and then obtain the overall longitudinal displacement data of switch rail under different conditions.The present application does not need big data driving, can realize efficient and high-precision measurement of switch rail longitudinal displacement under different environmental conditions, meet the demand of low cost, high stability and high precision railway field monitoring.

Description

Technical Field

[0001] This invention relates to the field of track inspection and monitoring, and in particular to a method for monitoring the longitudinal displacement of switch rails. Background Technology

[0002] In high-speed railway operation, turnouts are key components of the railway track. However, turnouts are characterized by their large number, complex structure, speed limitations, low operational safety, and high maintenance costs, making them a significant weak link in the track system. The turnout switch rail directly affects train speed and safety. Longitudinal displacement of the switch rail refers to the longitudinal displacement of the switch rail relative to the stock rail. Switch rail creep easily causes a lack of close contact between the switch rail and the stock rail, and is one of the main defects of turnouts.

[0003] Currently, there are three main methods for monitoring the longitudinal displacement of switch rails: image recognition monitoring, laser monitoring, and mechanical monitoring. Existing image recognition-based switch rail displacement monitoring primarily relies on industrial camera combinations combined with deep learning algorithms for displacement measurement. Deng Chenxin et al., in their invention patent application No. 202210362300.9, provided a "method for measuring the crawling of railway switch rails," which uses an image acquisition device to capture images of the switch rail and the main rail and obtain the coordinates of the switch rail edge. By comparing the actual distance between the switch rail edge and the boundary using a calibrated pixel scale, and comparing this distance with the initial distance before crawling, the crawling direction and distance are calculated. Wang Pengxiang et al., in their invention patent application No. 201710719956.0, provided a "method, device, and system for monitoring the crawling amount of switch rails based on image recognition," which uses an image acquisition device to obtain the position of the switch rail tip and the scale, compares the relative position of the switch rail tip edge before and after crawling, and calculates the crawling amount of the switch rail using the number of pixels and the distance they occupy. In their invention patent application No. 201610232538.4, Yin Hui et al. proposed a "method and system for monitoring switch rail telescopic displacement based on automatic image interpretation." This method uses a scale with integral characteristic chromaticity components to achieve precise image region extraction, and combines integral characteristic chromaticity components with digital matching to interpret the telescopic displacement of the switch rail. Regarding laser detection, Jia Zixiang et al., in their utility model patent application No. 202223202517.8, provided a "railway switch rail creep monitoring instrument." This instrument uses an infrared ranging module sensor to monitor the amount of switch rail creep, and incorporates a detachable sliding groove, a solar photovoltaic panel, and a silent pulley to achieve portable monitoring. Yan Dazhi et al., in their utility model patent application No. 202121861889.4, provided a "switch switch rail creep measurement device." This device uses a positioning reference set in a fixed component, and a scale bar and optical component set on a sliding component. It measures the displacement difference between the scale bar / optical component and the positioning surface to detect the creep amount between the switch rail and the main rail. In their invention patent application No. 201911258437.4, Chen Lei et al. provided a "video-based method for monitoring the crawling of turnout switch rails," which achieves crawling monitoring through switch rail edge contour recognition, thereby improving monitoring accuracy. In their utility model patent application No. 20152256527.0, Yang Lingzhi et al. provided a "turnout status detection system based on switch rail displacement," in which a laser displacement sensor is vertically pointed at the inner vertical end face of the switch rail, and an industrial control computer receives the sensor output signal, converts it into a digital signal, and outputs it to a data acquisition card for analysis.

[0004] The aforementioned image recognition and laser monitoring methods are affected by unstable factors such as train vibration, dust, rain, snow, and light, which can affect measurement accuracy. The subsequent image processing is difficult and cannot achieve the desired effect. In addition, the equipment for this solution is expensive, which is not conducive to its widespread adoption.

[0005] Currently, there is limited research on mechanical measurement and monitoring equipment. Existing mechanical measurement methods fall into two categories. One is the "Switch Rail Creep Monitoring Device" proposed by Tan Hua in his invention patent application number 20141283429.6, which uses an eddy current sensor to indirectly calculate the switch rail extension by measuring the change in the gap between the switch rail tip and the stock rail. However, the stability and accuracy of the eddy current sensor for identifying magnetized metal are low, and the technology is not yet perfect. The other is the "Integrated Real-Time Measurement Device for Longitudinal Creep and Close Contact Gap of Switch Rail" proposed by Ren Tongqun in his invention patent application number 20191630367.4, which decomposes the switch rail displacement into displacement change and angle change, and uses different sensors to measure them sequentially. However, this method only measures the switch rail tip, and the measured value is the absolute displacement of the switch rail, which does not conform to the definition of the longitudinal displacement of the switch rail.

[0006] In summary, image recognition and laser monitoring methods cannot overcome the influence of environmental factors and are too costly. There is limited research on mechanical measurement and monitoring equipment, and existing solutions have accuracy issues. Therefore, there is still a lack of a monitoring device with low error, high reliability, low cost, and easy installation and disassembly for switch rail displacement monitoring. Summary of the Invention

[0007] To address the problems of poor reliability, unstable accuracy, high maintenance costs, and complex tooling in existing switch rail displacement monitoring equipment, this invention proposes a method for monitoring longitudinal displacement of switch rails. This method utilizes a magnetostrictive sensor in a switch rail root-end monitoring device to collect data, thereby improving equipment reliability, reducing maintenance costs, and avoiding monitoring errors caused by lateral displacement of the rail.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for monitoring the longitudinal displacement of a switch rail, comprising a switch rail longitudinal displacement monitoring device, characterized in that... The switch rail longitudinal displacement monitoring device includes: a base rail structure, mounted on the base rail, comprising two sets of base rail clamps, a large-aperture pad, a small-aperture pad, and a magnetostrictive sensor; a switch rail structure, mounted at the heel end of the switch rail, comprising a set of switch rail clamps and a magnetic ring; the magnetostrictive sensor passes through the magnetic ring and is used to measure the switch rail displacement; each of the two sets of base rail clamps includes a rear clamp and a front clamp, connected by long bolts and installed on the rail bottom through clamp grooves; the switch rail clamp includes a rear clamp and a front clamp, connected by long bolts and installed on the rail bottom through clamp grooves; the magnetic ring is built into the front clamp and can be adjusted laterally and longitudinally within the top magnetic ring adjustment groove to ensure that the magnetostrictive sensor measuring rod passes through without contacting the magnetic ring; The method for monitoring the longitudinal displacement of the switch rail includes the following steps: S10, let the coordinate system of the longitudinal displacement monitoring device of the switch rail be O-XYZ, the X direction is the axial direction of the magnetostrictive sensor measuring rod, the Y direction is perpendicular to the top surface of the switch rail clamp, and the Z direction is along the radial direction of the measuring rod and parallel to the top surface of the switch rail clamp; S11, The longitudinal displacement monitoring device of the switch rail is installed on the bottom of the rail. Tighten the long bolts to ensure that the rear clamp is firmly connected to the front clamp of the switch rail. S12, place the magnetic ring inside the magnetic ring adjustment groove of the switch rail, adjust the magnetic ring to the appropriate position with non-magnetic material, so that the magnetostrictive sensor measuring rod passes through the inside of the magnetic ring, and fasten it with the switch rail clamp pad; S13, keep the longitudinal displacement monitoring equipment of the switch rail stable, and read the value manually or automatically at this moment, i.e., T. i At any given moment, the relative position (X) of the magnetic ring measuring point and the measuring rod. i The measurement results are transmitted and stored in the host computer in real time. S14, When longitudinal displacement occurs at the tip of the switch rail, the moment is read manually or automatically, i.e., T. j The relative position (X) of the magnetic ring measuring point and the measuring rod at any given time. j The measurement results are transmitted and stored in the host computer in real time. S15, Calculate the current longitudinal displacement d at the tip of the switch rail. ij =X j -X i ; S16, using the switch rail expansion formula The change in displacement at the tip of the switch rail is calculated to obtain the overall displacement of the switch rail. Where α is the coefficient of thermal expansion. Where L is the temperature change and L is the length of the switch rail; S17. Repeat steps S11 to S16 to obtain the longitudinal displacement of the switch rail at any time by capturing different time intervals ΔT.

[0010] Furthermore, the magnetostrictive sensor is disposed between the two sets of basic rail front end clamps, and the sensor electronic compartment is connected to the basic rail front end clamps through the cooperation of the fastening plate and the fastening hole.

[0011] Furthermore, the small-aperture pad, which cooperates with the front end clamp of the basic rail, is set on the inner side of the clamp and is connected by four short bolts to fasten the magnetostrictive sensor measuring rod.

[0012] Furthermore, the large-diameter pad is set on the outer side of the clamp at the front end of the basic rail and is connected by four short bolts to fasten the electronic compartment of the magnetostrictive sensor, ensuring that the longitudinal displacement of the switch rail measured each time is transmitted in real time and saved to the host computer.

[0013] Furthermore, it also includes a switch rail clamp pad, which is fastened to the magnetic ring adjustment groove with short bolts to secure the magnetic ring; the magnetic ring is built into the magnetic ring adjustment groove, which is filled with a non-magnetic elastic material to adjust the position of the magnetic ring and to cooperate with the switch rail clamp pad for fastening.

[0014] The present invention has the following advantages due to the adoption of the above technical solutions: 1. This invention addresses the problem of longitudinal displacement monitoring of switch rails by developing a contact measurement method based on the magnetostrictive principle, ensuring high monitoring accuracy of the overall detection device even in complex environments. Existing contact magnetostrictive measurement devices all measure the tip of the switch rail, neglecting the longitudinal displacement of the heel end, and are prone to significant errors during switch rail switching. This invention focuses on measuring the longitudinal displacement of the heel end of the switch rail, calculating the longitudinal displacement of the switch rail tip using the switch rail extension formula, and thus obtaining the overall displacement of the switch rail.

[0015] 2. This invention develops a universal, split-type tooling fixture, distinct from other contact-type magnetostrictive measuring devices. Its tooling principle ensures the stability of the entire system in complex environments. This invention employs a combination of mechanical structure and magnetostrictive sensors. A magnetic ring and measuring rod are used to monitor the longitudinal displacement of the switch rail by detecting position changes. The device consists of two basic rail assembly structures and one switch rail assembly structure. The fixtures involved in the basic rail assembly structure can be adjusted in position according to magnetostrictive sensors with different ranges. The magnetic ring within the switch rail assembly structure can move within an adjustment groove, ensuring no contact between it and the measuring rod. The non-magnetic material within the adjustment groove maximizes measurement accuracy and also acts as a buffer between the magnetic ring and the adjustment groove. This invention fills a technical gap in switch rail longitudinal displacement monitoring, improving equipment applicability and reducing maintenance costs. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the longitudinal displacement monitoring device for the switch rail according to one embodiment of the present invention; Figure 2 This is a schematic diagram of the basic rail clamp structure in one embodiment of the present invention; Figure 3 This is a schematic diagram of a magnetostrictive sensor structure according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the basic rail front end clamp structure in one embodiment of the present invention; Figure 5 This is a schematic diagram of the assembly structure of the magnetostrictive sensor and the front end fixture of the basic rail in one embodiment of the present invention; Figure 6 This is a schematic diagram of the rear clamp structure in one embodiment of the present invention; Figure 7 This is a schematic diagram of the clamp structure of the switch rail portion in one embodiment of the present invention; Figure 8 This is a schematic diagram of the tip rail front end clamp structure in one embodiment of the present invention; Figure 9 This is a schematic diagram of the longitudinal displacement monitoring method for the switch rail of the present invention; Figure label: 10-Basic rail device structure, 11-Rear end clamp, 111-Rear end clamp through hole, 112-Rear end clamp groove, 12-Basic rail front end clamp, 121-Basic rail front end clamp groove, 122-Basic rail front end clamp through hole, 123-Clamp connection hole, 124-Clamp inner side, 125-Clamp outer side, 13-Magnetostrictive sensor, 131-Wire, 132-Electronic compartment, 133-Connecting plate, 134-Measuring rod, 14-Small diameter pad, 15-Large diameter pad, 16-Basic rail; 20-Switch rail device structure, 21-Switch rail front end clamp, 211-Switch rail front end clamp groove, 212-Switch rail front end clamp through hole, 213-Magnetic ring adjustment groove, 214-Switch rail front end clamp top surface, 22-Switch rail clamp pad, 23-Magnetic ring, 24-Switch rail. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0019] This invention provides a device for monitoring the longitudinal displacement of a switch rail, comprising a base rail assembly and a switch rail assembly. The base rail assembly includes two sets of clamps (left and right) and a magnetostrictive sensor. Each clamp set includes a rear clamp, a front clamp of the base rail, a large (small) diameter pad, a long bolt, a short bolt, and a cotter pin. The switch rail assembly includes a rear clamp, a front clamp of the switch rail, a switch rail clamp pad, a magnetic ring, a long bolt, a short bolt, and a cotter pin. This invention, based on mechanical measurement and combined with a magnetostrictive sensor, achieves accurate monitoring of the longitudinal displacement at the root end of the switch rail, improving equipment reliability and reducing maintenance costs.

[0020] In one embodiment of the present invention, such as Figure 1 As shown, a longitudinal displacement monitoring device for a switch rail is provided, comprising: The basic rail device structure 10 is installed on the basic rail. There are two sets in total. The front clamps 12 of the basic rail are installed in the same direction and are respectively set on the front and rear sides of the magnetostrictive sensor 13.

[0021] Both sets of basic rail device structures 10 include a rear clamp 11 and a front clamp 12 of the basic rail; the rear clamp 11 and the front clamp 12 of the basic rail are connected by long bolts, and the magnetostrictive sensor 13 is installed between the two front clamps 12 of the basic rail.

[0022] The switch rail device structure 20 is installed at the root end of the switch rail and is connected to the rear clamp 11 and the front clamp 21 of the switch rail by long bolts. The front clamp 21 of the switch rail has a built-in magnetic ring 23, and the magnetostrictive sensor 13 passes through the magnetic ring 23 to measure the displacement of the switch rail.

[0023] In this embodiment, the materials of the front end clamp of the switch rail and the front end clamp of the base rail can be aluminum or other non-magnetic materials, thereby ensuring the accuracy of the present invention in the monitoring process.

[0024] In the above embodiments, such as Figures 2-6 As shown, the basic rail device structure 10 includes: The basic rail front end clamp 12 has a through hole 122 connected to a long bolt, and the basic rail front end clamp groove 121 is connected to the bottom of the basic rail 16 and is opposite to the rear end clamp groove 112. The rear clamp 11 has a through hole 111 connected to a long bolt, and a groove 112 connected to the bottom of the base rail 16, which is opposite to the front clamp groove 121 of the base rail. The magnetostrictive sensor 13 is installed between the front end clamps 12 of the two basic rails. On one side, the connecting plate 133 is installed inside the clamp connecting hole 123 and fastened with the large-diameter pad 14. On the other side, the measuring rod 134 passes through the clamp fastening hole 123 and is fastened with the small-diameter pad 15. A large-diameter pad 14 is installed on the inner side 124 of one of the clamps to fasten the measuring rod 134. A small-diameter pad 15 is installed on the outer side 125 of another clamp to fasten the connecting plate 133; In the above embodiments, such as Figures 6-8 As shown, the switch rail device structure 20 includes: The rear clamp 11 has a through hole 111 connected to a long bolt, and a groove 112 connected to the bottom of the switch rail 24, which is opposite to the front clamp groove 211 of the switch rail. The front end clamp 21 of the switch rail has a through hole 212 connected to a long bolt, and the groove 211 of the front end clamp is connected to the bottom of the switch rail 24 and is opposite to the groove 112 of the rear end clamp. The switch rail clamp pad 22 is fastened to the magnetic ring adjustment groove 213 with short bolts to secure the magnetic ring. The magnetic ring 23 is built into the magnetic ring adjustment groove 213. The magnetic ring adjustment groove 213 can be filled with non-magnetic elastic material to adjust the position of the magnetic ring 23 and to be fastened in conjunction with the switch clamp pad 22.

[0025] A method for monitoring the longitudinal displacement of a switch rail is also provided, which uses the aforementioned longitudinal displacement monitoring device for the switch rail and includes the following steps: S10, let the coordinate system of the longitudinal displacement monitoring device of the switch rail be O-XYZ, the X direction is the axial direction of the magnetostrictive sensor measuring rod, the Y direction is perpendicular to the top surface of the switch rail clamp, and the Z direction is along the radial direction of the measuring rod and parallel to the top surface of the switch rail clamp; S11, The longitudinal displacement monitoring device of the switch rail is installed on the bottom of the rail. Tighten the long bolts to ensure that the rear clamp is firmly connected to the front clamp of the switch rail. S12, place the magnetic ring inside the magnetic ring adjustment groove of the switch rail, adjust the magnetic ring to the appropriate position with non-magnetic material, so that the magnetostrictive sensor measuring rod passes through the inside of the magnetic ring, and fasten it with the switch rail clamp pad; S13, keep the longitudinal displacement monitoring equipment of the switch rail stable, and read the value manually or automatically at this moment, i.e., T. i At any given moment, the relative position (X) of the magnetic ring measuring point and the measuring rod. i The measurement results are transmitted and stored in the host computer in real time. S14, When longitudinal displacement occurs at the tip of the switch rail, the moment is read manually or automatically, i.e., T. j The relative position (X) of the magnetic ring measuring point and the measuring rod at any given time. j The measurement results are transmitted and stored in the host computer in real time. S15, Calculate the current longitudinal displacement d at the tip of the switch rail. ij =X j -X i ; S16, using the switch rail expansion formula The change in displacement at the tip of the switch rail is calculated to obtain the overall displacement of the switch rail. Where α is the coefficient of thermal expansion. Where L is the temperature change and L is the length of the switch rail; S17, Repeat steps S11 to S16 to extract different time intervals. This allows us to obtain the longitudinal displacement of the switch rail at any given time.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for monitoring the longitudinal displacement of a switch rail, comprising a switch rail longitudinal displacement monitoring device, characterized in that, The switch rail longitudinal displacement monitoring device includes: a base rail structure, mounted on the base rail, comprising two sets of base rail clamps, a large-aperture pad, a small-aperture pad, and a magnetostrictive sensor; a switch rail structure, mounted at the heel end of the switch rail, comprising a set of switch rail clamps and a magnetic ring; the magnetostrictive sensor passes through the magnetic ring and is used to measure the switch rail displacement; each of the two sets of base rail clamps includes a rear clamp and a front clamp, connected by long bolts and installed on the rail bottom through clamp grooves; the switch rail clamp includes a rear clamp and a front clamp, connected by long bolts and installed on the rail bottom through clamp grooves; the magnetic ring is built into the front clamp and can be adjusted laterally and longitudinally within the top magnetic ring adjustment groove to ensure that the magnetostrictive sensor measuring rod passes through without contacting the magnetic ring; The method for monitoring the longitudinal displacement of the switch rail includes the following steps: S10, let the coordinate system of the longitudinal displacement monitoring device of the switch rail be O-XYZ, the X direction is the axial direction of the magnetostrictive sensor measuring rod, the Y direction is perpendicular to the top surface of the switch rail clamp, and the Z direction is along the radial direction of the measuring rod and parallel to the top surface of the switch rail clamp; S11, The longitudinal displacement monitoring device of the switch rail is installed on the bottom of the rail. Tighten the long bolts to ensure that the rear clamp is firmly connected to the front clamp of the switch rail. S12, place the magnetic ring inside the magnetic ring adjustment groove of the switch rail, adjust the magnetic ring to the appropriate position with non-magnetic material, so that the magnetostrictive sensor measuring rod passes through the inside of the magnetic ring, and fasten it with the switch rail clamp pad; S13, keep the longitudinal displacement monitoring equipment of the switch rail stable, and read the value manually or automatically at this moment, i.e., T. i At any given moment, the relative position (X) of the magnetic ring measuring point and the measuring rod. i The measurement results are transmitted and stored in the host computer in real time. S14, When longitudinal displacement occurs at the tip of the switch rail, the moment is read manually or automatically, i.e., T. j The relative position (X) of the magnetic ring measuring point and the measuring rod at any given time. j The measurement results are transmitted and stored in the host computer in real time. S15, Calculate the current longitudinal displacement d at the tip of the switch rail. ij =X j -X i ; S16, using the switch rail expansion formula The change in displacement at the tip of the switch rail is calculated to obtain the overall displacement of the switch rail. , where α is the coefficient of thermal expansion, Δt is the temperature change, and L is the length of the switch rail; S17. Repeat steps S11 to S16 to obtain the longitudinal displacement of the switch rail at any time by capturing different time intervals ΔT.

2. The method for monitoring longitudinal displacement of the switch rail according to claim 1, characterized in that: The magnetostrictive sensor is positioned between the two sets of front-end clamps of the basic rails, and the sensor's electronic compartment is connected to the front-end clamps of the basic rails through a fastening plate and a fastening hole.

3. The method for monitoring longitudinal displacement of the switch rail according to claim 1, characterized in that: The small-aperture pad, which cooperates with the front end clamp of the basic rail, is set on the inner side of the clamp and is connected by four short bolts to fasten the magnetostrictive sensor measuring rod.

4. The method for monitoring longitudinal displacement of the switch rail according to claim 1, characterized in that: The large-diameter pad is set on the outer side of the clamp at the front end of the basic rail and is connected by four short bolts to fasten the electronic compartment of the magnetostrictive sensor, ensuring that the longitudinal displacement of the switch rail measured each time is transmitted in real time and saved to the host computer.

5. The method for monitoring longitudinal displacement of the switch rail according to claim 1, characterized in that: It also includes a switch rail clamp pad, which is fastened to the magnetic ring adjustment groove with short bolts to secure the magnetic ring; the magnetic ring is built into the magnetic ring adjustment groove, which is filled with non-magnetic elastic material to adjust the position of the magnetic ring and to cooperate with the switch rail clamp pad for fastening.

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