Rail load detection system

Abstract

The present invention discloses a track load detection system, which belongs to the field of rail transportation. It includes rails and sleepers in a detection area, and shear sensors arranged on the rails. For the rails on one side, no less than two detection positions are arranged on the waist of a section of rail in each of two adjacent sleepers, and a shear sensor is arranged on each detection position; the shear sensors of two adjacent detection positions in two adjacent sleepers are bridged, and the shear sensors of the set detection positions in two adjacent sleepers are bridged with the shear sensors of the set detection positions in the next two adjacent sleepers; each shear sensor is connected to a processor. The present invention does not use a weighing sensor, has a simple structure, is easy to install, does not require modification of the existing roadbed, sleepers, or fasteners, and can complete projects that cannot be completed by existing technologies, such as high-speed railways and subways, which are sensitive to modification and have construction time constraints, thereby reducing construction time, cost, and safety hazards caused by construction.

Description

Technical Field

[0001] The present invention relates to the field of rail transportation, and in particular to a rail load detection system. Background Art

[0002] The interaction between wheels and rails directly affects railway driving safety, wheel-rail wear and maintenance. Currently, a large number of uninterrupted tracks have been installed in the domestic railway, subway and urban rail industries. The interaction force between wheels and uninterrupted tracks is measured using track weighing devices.

[0003] Specifically, shear force sensors installed on the rails mechanically separate the detection area from the line. Load cells are then placed in the detection area to complement the shear force sensors, eliminating the mechanical effects of the line passing through the rails on the detection area, thereby achieving weighing. However, this method requires the cooperation of two sensors, especially the load cell, whose elastic body requires a certain amount of installation space, thus imposing a minimum size restriction.

[0004] Load cell installation requires modifications to existing sleepers, trackbeds, and fasteners. This labor-intensive, complex process (such as demolishing the existing structure and casting a new one) and time-consuming process pose safety risks during construction and operation. This makes this detection method unsuitable for applications such as high-speed rail lines, motorway lines, and subway lines. In these applications, modifying the existing structure often results in a short window period (the time available for on-track construction): typically three hours per day for subways, but variable for high-speed rail lines. Summary of the Invention

[0005] The present invention provides a track load detection system with a simple structure and convenient installation, which reduces construction time, cost and potential safety hazards caused by construction.

[0006] The present invention provides the following technical solutions:

[0007] A track load detection system includes rails and sleepers in a detection area, and shear force sensors arranged on the rails, wherein:

[0008] The shear force sensors are installed on the rails on both sides in the same way. For the rails on one side, no less than two detection positions are set on the waist of a section of rail in each two adjacent sleepers, and a shear force sensor is set at each detection position; the shear force sensors at two adjacent detection positions in two adjacent sleepers are bridged, and the shear force sensors at the set detection positions in two adjacent sleepers are bridged with the shear force sensors at the set detection positions in the next two adjacent sleepers; each shear force sensor is connected to the processor.

[0009] Furthermore, the number of detection positions on the waist of a section of rail between every two adjacent sleepers is two. In the order of the detection positions, the shear force sensor at the Nth detection position is bridged with the N+1th detection position, and the shear force sensor at the Nth detection position is bridged with the N+3th detection position, where N = 1, 3, 5, 7, ...

[0010] Furthermore, the detection area is located in the straight section of the rail, the length of the detection area is greater than the circumference of the wheel, the distance between the detection position closest to the sleeper and the sleeper is not less than half the height of the rail, and the distance between two adjacent detection positions in two adjacent sleepers is in the range of 200 to 300 mm.

[0011] Furthermore, each detection position is provided with two shear force sensors, and the two shear force sensors at the same detection position are symmetrically installed on both sides of the detection position of the rail waist.

[0012] Furthermore, the shear force sensor is mounted on the waist of the rail through a mounting bracket, wherein:

[0013] The mounting bracket includes two symmetrical bracket units, which are symmetrically arranged on both sides of the rail. The upper part of each bracket unit presses the shear force sensor against the side of the rail waist of the rail through a first set of bolts, and the lower parts of the two bracket units are fastened together by a second set of bolts.

[0014] Furthermore, the bracket unit includes a sensor mounting portion and a bracket unit connecting portion, the sensor mounting portion is located at a set distance outside the rail waist of the rail, the bracket unit connecting portion is located below the sensor mounting portion, and the bracket unit connecting portion extends from the bottom of the rail to the inside of the rail;

[0015] The shear force sensor is pressed against the side surface of the rail waist by the first set of bolts on the sensor mounting portion of each bracket unit, and the bracket unit connecting portions of the two bracket units are connected and fastened together by the second set of bolts.

[0016] Furthermore, a disc spring gasket is provided between the first set of bolts and the shear force sensor, and a protective cover is provided outside the mounting bracket.

[0017] Furthermore, the shape of the inner side of the lower portion of the bracket unit corresponds to the shape of the lower portion of the rail.

[0018] The present invention has the following beneficial effects:

[0019] Compared to existing technologies, the present invention does not use load cells. Instead, it simply installs shear force sensors on the rails between each pair of sleepers within the detection zone, preferably in the middle of the rail waist. At least two sets of shear force sensors are installed between adjacent sleepers. The shear force sensors are arranged continuously to achieve the required detection zone length. By continuously configuring the shear force sensors and implementing the present invention's specific bridge assembly and data processing schemes, the precise weight of the vehicle can be determined, while also capturing the waveform of each wheel rotation. Specific processing of the waveforms allows for weighing and tread damage detection.

[0020] The present invention does not use weighing sensors, has a simple structure, is easy to install, and does not require modification of existing roadbeds, sleepers, or fasteners. It can complete projects that cannot be completed by existing technologies, such as high-speed railways and subways, which are sensitive to modification and have construction time constraints (short window period, usually 3 hours per day), reducing construction time, costs and safety hazards caused by construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a side view of the rail load detection system of the present invention;

[0022] Figure 2 is a top view of the rail load detection system of the present invention;

[0023] Figure 3 Schematic diagram of the shear sensor bridge;

[0024] Figure 4 This is the installation cross-sectional view of the shear force sensor;

[0025] Figure 5 This is the side view of the shear force sensor installation;

[0026] Figure 6 This is an example diagram of the waveform of the shear force sensor at the first detection position;

[0027] Figure 7 This is an example diagram of the waveform of the shear force sensor at the 4th detection position;

[0028] Figure 8 for Figure 6 and Figure 7 Example diagram of the synthesized waveform after addition;

[0029] Figure 9 A waveform graph composed of various synthetic waveforms;

[0030] Figure 10 This is a schematic diagram of the waveform curve after straight line fitting;

[0031] Figure 11 It is a schematic diagram after curve fitting of the waveform curve graph;

[0032] Figure 12 is the fitting curve corresponding to the wheel flat defect;

[0033] Figure 13 is the fitting curve corresponding to the wheel polygon defect. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0035] The present invention provides a track load detection system, such as Figure 1-5 As shown, the detection area includes a rail 1 and a sleeper 2, and a shear force sensor 3 arranged on the rail 1, wherein:

[0036] The rails on both sides are installed with shear force sensors 3 in the same manner. For the rails 1 on one side, no less than two detection positions 5 are provided on the rail waist 4 of a section of rail within each two adjacent sleepers 2, and each detection position 5 is provided with a shear force sensor 3; the shear force sensors of two adjacent detection positions 5 within two adjacent sleepers 2 are bridged, and the shear force sensors at the set detection positions within two adjacent sleepers 2 are bridged with the shear force sensors at the set detection positions within the next two adjacent sleepers 2; each shear force sensor 3 is connected to the processor.

[0037] The existing technology requires the removal of the original sleepers and replacement with sleepers that can be installed with weighing sensors. If it is an integral roadbed or track plate, the sleeper part needs to be modified, and the original sleepers need to be planed out and modified into sleepers suitable for installing vertical force sensors. The construction workload is large and the cycle is long. In particular, the maintenance of the newly poured materials and the support during the transition period need to be coordinated during the modification process. Therefore, a construction period of more than 2 months is usually required. At the same time, the changes to the original structure bring unknown safety hazards.

[0038] Compared to existing technologies, the present invention does not use load cells. Instead, it simply installs shear force sensors on the rails between each pair of sleepers within the detection zone, preferably in the middle of the rail waist. At least two sets of shear force sensors are installed between adjacent sleepers. The shear force sensors are arranged continuously to achieve the required detection zone length. By continuously configuring the shear force sensors and implementing the present invention's specific bridge assembly and data processing schemes, the precise weight of the vehicle can be determined, while also capturing the waveform of each wheel rotation. Specific processing of the waveforms allows for weighing and tread damage detection.

[0039] The present invention does not use weighing sensors, has a simple structure, is easy to install, and does not require modification of existing roadbeds, sleepers, or fasteners. It can complete projects that cannot be completed by existing technologies, such as high-speed railways and subways, which are sensitive to modification and have construction time constraints (short window period, usually 3 hours per day), reducing construction time, costs and safety hazards caused by construction.

[0040] Exemplarily, the number of detection positions on the waist of a section of rail between every two adjacent sleepers is two. In the order of the detection positions, the shear force sensor at the Nth detection position is bridged with the N+1th detection position, and the shear force sensor at the Nth detection position is bridged with the N+3th detection position, where N = 1, 3, 5, 7, ...

[0041] That is, the shear force sensors are connected at the first and second detection positions, the third and fourth detection positions, and so on. Similarly, the shear force sensors are connected at the first and fourth detection positions, the third and sixth detection positions, and so on. This allows for continuous wheel load measurements and the detection of wheel damage without blind spots. The waveform of the vehicle load passing through the detection area is acquired, and by fitting these waveforms, the influence of the sleepers in the detection area is eliminated, resulting in an accurate wheel load measurement (load value).

[0042] The aforementioned inspection zone is located on the straight section of the rail. The length of the inspection zone is greater than the circumference of the wheel, allowing for complete wheel inspection and eliminating blind spots. The spacing between the inspection position closest to the sleeper and the sleeper is no less than half the height of the rail. The spacing between two adjacent inspection positions within two adjacent sleepers ranges from 200 to 300 mm, preferably 270 mm.

[0043] Each detection position is provided with two shear force sensors, and the two shear force sensors at the same detection position are symmetrically installed on both sides of the detection position of the rail waist.

[0044] For example, within the detection area, two pairs of H-shaped shear force sensors are installed on a single rail between two sleepers. A shear force sensor is installed on each side of the rail at the same cross-section, forming a pair of shear force sensors. Shear force sensors are installed on the rail on the other side in the same manner.

[0045] The aforementioned shear force sensor is mounted on the rail waist 4 of the rail 1 via a mounting bracket 6, wherein:

[0046] The mounting bracket 6 includes two symmetrical bracket units 7 and 8, which are symmetrically arranged on both sides of the rail 1. The upper part of each bracket unit 7 or 8 presses the shear force sensor 3 onto the side of the rail waist 4 of the rail 1 through a first set of bolts 11, and the lower parts of the two bracket units 7 and 8 are connected and fastened together by a second set of bolts 12.

[0047] Specifically, each bracket unit 7 or 8 includes a sensor mounting portion 9 and a bracket unit connecting portion 10, the sensor mounting portion 9 is located at a set distance outside the rail waist 4 of the rail 1, the bracket unit connecting portion 10 is located below the sensor mounting portion 9, and the bracket unit connecting portion 10 extends from the bottom of the rail 1 to the inside of the rail 1.

[0048] The shear force sensor 3 is pressed against the side of the rail waist 4 of the rail 1 by a first set of bolts 11 on the sensor mounting portion 9 of each bracket unit 7 or 8, and the bracket unit connecting portions 10 of the two bracket units 7 and 8 are connected and fastened together by a second set of bolts 12.

[0049] The shape of the inner side of the lower portion of the bracket unit 7 or 8 corresponds to the shape of the lower portion of the rail 1 , and the inner side of the lower portion of the bracket unit 7 or 8 is clamped on the lower portion of the rail 1 during installation.

[0050] The present invention does not require any damage such as drilling on the original rails. The shear force sensor 3 is pressed against the side of the rail waist 4 by inwardly clamping two symmetrical bracket units 7 and 8, thereby reducing potential safety hazards to the rails.

[0051] During installation, simply bolt the sensor to the rail using a fixture and connect the sensor cable to the trackside electrical control box. Including commissioning time, this typically takes less than 15 hours. With a three-hour window per day, a project can be completed in five days.

[0052] A disc spring washer 13 is provided between the first set of bolts 11 and the shear force sensor 3 for buffering, and a protective cover 14 is provided outside the mounting bracket 6 to protect the internal structure.

[0053] An embodiment of the present invention further provides a detection method for the aforementioned rail load detection system, wherein the rails on both sides are detected using the same method, wherein the method includes:

[0054] S1: For the rail on one side, the processor obtains the waveform of the shear force sensor at each detection position when the wheel passes through the detection area. The horizontal axis of the waveform is time, and the vertical axis is the output value of the shear force sensor.

[0055] S2: Add the waveforms of the shear force sensors at the Nth detection position and the N+3th detection position to obtain a composite waveform.

[0056] For example, when N=1, the waveform of the shear force sensor at the first detection position is as follows: Figure 6 As shown, the waveform of the shear force sensor at the 4th detection position is as follows Figure 7 The composite waveform of the two is shown as Figure 8 When N=3, 5, 7, ..., a similar series of synthetic waveforms can be obtained.

[0057] S3: Based on the horizontal axis, each synthesized waveform is displayed in the same coordinate system in chronological order to obtain a waveform curve graph.

[0058] For example, the waveform graph is as follows Figure 9 shown.

[0059] S4: Based on the waveform curve graph, the top straight portion of each synthetic waveform is fitted into a straight line, and the load force is determined according to the fitted straight line to complete the weighing.

[0060] For example, after fitting, Figure 10 As shown, a continuous detection area is formed from the first detection position to the last shear detection position. Figure 10 In the figure, the horizontal axis is time and the vertical axis is the shear force value. The shear force value corresponding to the fitted straight line is the load force, which realizes weighing.

[0061] Once the wheel is damaged, the mechanical characteristics such as load vibration will also be reflected in the waveform curve. Based on the characteristics of the load force, the tread damage can be detected. Based on this, the detection method of the present invention also includes:

[0062] S5: Based on the waveform curve graph, curve fitting is performed on the top straight portion of each synthetic waveform, and the damage type of the wheel tread is determined according to the shape characteristics of the fitting curve obtained by fitting.

[0063] The fitting curve obtained is as follows Figure 11 As shown in Figure 1, when the wheel tread is damaged, the instantaneous center of rotation of the wheel will change. This change will cause the wheel to have a vertical impact speed on the rail, thereby generating an impact load (such as Figure 11 By analyzing the characteristics of the impact load, the damage and damage type of the wheel tread can be determined.

[0064] Specifically, S5 includes:

[0065] The shape characteristics of the fitting curve are compared with the curve characteristics of various damage types obtained in advance, and the damage type of the wheel tread is determined based on the similarity.

[0066] Among them, the curve characteristics of various damage types are obtained in advance through the following process:

[0067] 1. Obtain in advance the fitting curves of wheels without tread defects and wheels with treads of various types of damage when they pass through the inspection area.

[0068] First, shear force data of multiple sets of wheels without tread defects passing through the inspection area at different loads and speeds are collected, and the above shear force data are statistically analyzed to analyze the wheel-rail force curve characteristics of wheels without tread defects.

[0069] Then, multiple sets of shear force data of certain tread damage, such as polygonal defects and wheel flat scar defects, are collected; the above shear force data are statistically analyzed to analyze the wheel-rail force curve characteristics of the wheel with this type of tread damage. Figure 12 and Figure 13 Examples of fitting curves for wheel flat defects and polygonal defects are given respectively.

[0070] 2. Determine the curve characteristics of various damage types in advance based on the difference between the fitting curves when wheels with treads of various damage types pass through the detection area and the fitting curves when wheels without tread defects pass through the detection area.

[0071] That is, the difference between the two curves is analyzed and extracted as the basis for defect determination, namely the curve characteristics of the damage type. The above operation is performed for all currently known wheel tread damage types to determine the determination criteria for each tread damage.

[0072] After obtaining the curve characteristics of each damage type in advance, during testing, the shape characteristics of the actual fitting curve are compared with the curve characteristics of the wheel tread damage of that type. The similarity of their geometric shapes is analyzed to determine the accuracy of the damage type. If the accuracy is greater than 90% (which can be set), it is defined as that type of damage.

[0073] As an improvement to the embodiment of the present invention, the method further includes:

[0074] S6: Taking the selected detection position as a reference, obtaining a fitting curve of the shear force sensor at the selected detection position when each wheel pair of the train passes through the selected detection position.

[0075] For example, the shear force sensor at the first detection position in the detection area in the direction of train travel can generally be selected as the data acquisition source for wheel positioning.

[0076] S7: Based on the horizontal axis, the fitting curves of each wheel pair are displayed in the same coordinate system in chronological order to obtain a continuous waveform data set.

[0077] When the train passes the shear force sensor at the detection position, the shear force sensor continuously acquires the wheel-rail force waveform of each wheel pair passing through the shear force sensor; these waveforms are arranged in the acquired waveform data set in time axis order.

[0078] S8: When there is damage on the tread of a certain wheel, the number of the fitting curve is located on the continuous waveform data set to obtain the wheel pair sequence number.

[0079] S9: The train number is obtained by taking photos and identifying the system through the vehicle number acquisition system. The damaged wheelset is located by the train number and the wheel pair serial number.

[0080] The train number acquisition system is generally installed behind the detection area, takes photos of the train, and identifies the train number through an algorithm.

[0081] S10: According to the correspondence between the shear force sensors of the rails on both sides of the same detection position, the left wheel or the right wheel of the wheel pair with damage is located, thereby achieving the positioning of the damaged wheel.

[0082] The same detection position corresponds to two rails, that is, two sets of shear force sensors. According to the corresponding relationship between the fitting curve of tread damage and the shear force sensors of the two rails, the left or right wheel of the wheel pair can be obtained, thereby locating the damaged wheel.

[0083] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A rail load detection system, characterized in that: The invention comprises a steel rail and a sleeper in a detection area, and a shear force sensor arranged on the steel rail, wherein: The shear force sensors are installed in the same manner on the rails on one side. For the rails on one side, at least two detection positions are set on the rail waist of a section of the rail within each two adjacent sleepers, and each detection position is provided with a shear force sensor; the shear force sensors at two adjacent detection positions within two adjacent sleepers are bridged, and the shear force sensors at the set detection positions within two adjacent sleepers are bridged with the shear force sensors at the set detection positions within the next two adjacent sleepers; each shear sensor is connected to the processor; There are two detection positions on the rail web of a section of rail between two adjacent sleepers. In the order of the detection positions, the shear force sensor at the Nth detection position is bridged with the shear force sensor at the N+1th detection position, and the shear force sensor at the Nth detection position is bridged with the shear force sensor at the N+3th detection position, where N = 1, 3, 5, 7, ...; The rails on both sides of the track load detection system are detected using the same detection method, which includes: S1: For the rail on one side, the processor obtains the waveform of the shear force sensor at each detection position when the wheel passes through the detection area. The horizontal axis of the waveform is time, and the vertical axis is the output value of the shear force sensor; S2: Add the waveforms of the shear force sensors at the Nth detection position and the N+3th detection position to obtain a composite waveform; S3: Based on the horizontal axis, each synthesized waveform is displayed in the same coordinate system in chronological order to obtain a waveform curve graph; S4: Based on the waveform graph, the top flat portion of each synthetic waveform is fitted into a straight line, and the load force is determined according to the fitted straight line to complete the weighing; S5: Based on the waveform curve graph, curve fitting is performed on the top straight portion of each synthetic waveform, and the damage type of the wheel tread is determined according to the shape characteristics of the fitting curve obtained by fitting.

2. The rail load detection system according to claim 1, characterized in that: The detection area is located in the straight section of the rail, the length of the detection area is greater than the circumference of the wheel, the distance between the detection position closest to the sleeper and the sleeper is not less than half the height of the rail, and the distance between two adjacent detection positions in two adjacent sleepers is in the range of 200 to 300 mm.

3. The rail load detection system according to claim 1 or 2, characterized in that: Each detection position is provided with two shear force sensors, and the two shear force sensors at the same detection position are symmetrically installed on both sides of the detection position of the rail waist.

4. The rail load detection system according to claim 3, characterized in that: The shear force sensor is mounted on the rail waist of the rail via a mounting bracket, wherein: The mounting bracket includes two symmetrical bracket units, which are symmetrically arranged on both sides of the rail. The upper part of each bracket unit presses the shear force sensor against the side of the rail waist of the rail through a first set of bolts, and the lower parts of the two bracket units are fastened together by a second set of bolts.

5. The rail load detection system according to claim 4, characterized in that: The bracket unit includes a sensor mounting portion and a bracket unit connecting portion, wherein the sensor mounting portion is located at a set distance outside the rail waist of the rail, the bracket unit connecting portion is located below the sensor mounting portion, and the bracket unit connecting portion extends from the bottom of the rail to the inside of the rail; The shear force sensor is pressed against the side surface of the rail waist by the first set of bolts on the sensor mounting portion of each bracket unit, and the bracket unit connecting portions of the two bracket units are connected and fastened together by the second set of bolts.

6. The rail load detection system according to claim 5, characterized in that: A disc spring washer is provided between the first group of bolts and the shear force sensor, and a protective cover is provided outside the mounting bracket.

7. The rail load detection system according to claim 5, characterized in that: The shape of the inner side of the lower portion of the bracket unit corresponds to the shape of the lower portion of the rail.

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