Wheel tread inspection device, wheel tread inspection system, and wheel tread inspection method

Abstract

To obtain a wheel tread inspection device capable of inspecting a tread abnormality of a wheel of a railway vehicle in a vibration detectable range.SOLUTION: A wheel tread inspection device 10 includes: a vibration sensor 11 that detects a vibration of a longitudinal wave and a vibration of a transverse wave among vibrations transmitted through a rail on which a railway vehicle travels; and a wheel identification section 12 that estimates, when a vibration occurs on the rail, an occurrence time at which the vibration occurs on the rail and an occurrence position on the rail at which the vibration occurs from a difference between a detection time at which the vibration sensor 11 detects the vibration of the longitudinal wave and a detection time at which the vibration sensor 11 detects the vibration of the transverse wave, and identifies a wheel of the railway vehicle located at the occurrence position at the occurrence time as a wheel that causes the occurrence of the vibration on the basis of a position of the railway vehicle at the occurrence time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wheel tread inspection device, a wheel tread inspection system, and a wheel tread inspection method for inspecting the condition of the wheel tread of a railway vehicle. [Background technology]

[0002] Conventionally, in the maintenance of railway vehicles, the task of determining whether or not a wheel has a flat during sudden braking or other such events is time-consuming because it requires inspecting many wheels on the entire train. Therefore, there is a need for an automatic inspection device for wheel tread abnormalities, including wheel flats. A useful function of an automatic inspection device for wheel tread abnormalities is the ability to not only determine whether or not a wheel tread abnormality is present, but also to identify wheels with abnormalities. For example, Patent Document 1 discloses a technology for a wheel damage detection device that uses two vibration accelerometers and a wheel detector to detect vibrations generated at the contact point between the wheel and the rail, detects wheel tread abnormalities based on the magnitude of the vibration detected by the vibration accelerometers, and identifies wheels with abnormalities based on the time difference between the vibration peaks detected by the two vibration accelerometers. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-85273 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned conventional technology, the vibration occurrence position can be identified only when the vibration occurs between the two accelerometers. Therefore, even if the two accelerometers can detect the vibration, if the vibration occurs in a range other than between the two accelerometers, the vibration occurrence position cannot be identified.

[0005] The present disclosure has been made in consideration of the above, and aims to provide a wheel tread inspection device that can inspect the tread abnormalities of railway vehicle wheels within a range in which vibrations can be detected. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, the wheel tread inspection device of the present disclosure is characterized by comprising: a vibration sensor that detects longitudinal wave vibrations and transverse wave vibrations among the vibrations that are transmitted through the rails on which the railway vehicle runs; and a wheel identification unit that, when vibrations occur on the rails, estimates the time of occurrence and the position on the rail where the vibration occurred from the difference between the detection time when the vibration sensor detects longitudinal wave vibrations and the detection time when the vibration sensor detects transverse wave vibrations, and identifies the wheel of the railway vehicle that was at the occurrence position at the time of occurrence as the wheel that caused the vibration to occur, based on the position of the railway vehicle at the time of occurrence. [Effects of the Invention]

[0007] According to the present disclosure, the wheel tread inspection device has the advantage of being able to inspect the tread abnormalities of the wheels of a railway vehicle within a range in which vibrations can be detected. [Brief explanation of the drawings]

[0008] [Figure 1] A block diagram showing a configuration example of a wheel tread inspection system according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing an example of installation of a vibration sensor provided in a wheel tread inspection device according to the first embodiment. [Figure 3] FIG. 1 is a diagram for explaining a method in which the wheel identification unit included in the wheel tread inspection device according to the first embodiment estimates the time when vibration occurred on the rail and the position on the rail where the vibration occurred. [Figure 4] As a comparative example, the following figure is a diagram illustrating the operation of determining the time when vibration occurred on the rail and the position on the rail where the vibration occurred, in the method described in Patent Document 1 described in the background art. [Figure 5] 1 is a flowchart showing the operation of the wheel tread inspection device according to the first embodiment. [Figure 6] FIG. 1 is a diagram showing an example of a case where a processing circuit for realizing a wheel tread inspection device according to a first embodiment is configured with a processor and a memory. [Figure 7] FIG. 1 is a diagram showing an example in which a processing circuit for realizing the wheel tread inspection device according to the first embodiment is configured with dedicated hardware. [Figure 8] A block diagram showing a configuration example of a wheel tread inspection system according to a second embodiment. [Figure 9] FIG. 10 is a diagram showing an image of the operation of a wheel identification unit provided in the wheel tread inspection device according to the second embodiment. [Figure 10] 10 is a flowchart showing the operation of a wheel identification unit provided in a wheel tread inspection device according to a second embodiment. [Figure 11] FIG. 10 is a diagram showing an image of the operation of a wheel identification unit provided in the wheel tread inspection device according to the third embodiment. [Figure 12] 10 is a flowchart showing the operation of a wheel identification unit provided in a wheel tread inspection device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wheel tread inspection device, a wheel tread inspection system, and a wheel tread inspection method according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0010] Embodiment 1 Fig. 1 is a block diagram showing an example configuration of a wheel tread inspection system 30 according to a first embodiment. The wheel tread inspection system 30 includes a wheel tread inspection device 10 and a railway vehicle position detection device 20. The wheel tread inspection device 10 is a device that inspects the condition of the tread of a wheel provided on a railway vehicle (not shown). The wheel tread inspection device 10 detects flats that occur on the wheel tread when the railway vehicle performs sudden braking, for example.

[0011] The railcar position detection device 20 detects the position of the railcar to be inspected by the wheel tread inspection device 10. The railcar position detection device 20 may be a device dedicated to the wheel tread inspection system 30, or may be a device that is not dedicated to the wheel tread inspection system 30 but is also used for other purposes. If the railcar position detection device 20 is a device dedicated to the wheel tread inspection system 30, the railcar position detection device 20 detects the position of the railcar using, for example, a proximity sensor or an axle sensor. If the railcar position detection device 20 is not a device dedicated to the wheel tread inspection system 30 but is also used for other purposes, the railcar position detection device 20 is, for example, a device that detects the position of the railcar in a system such as CBTC (Communication Based Train Control), but may also be a server that acquires information on the position of the railcar in a system such as CBTC.

[0012] A detailed description will be given of the configuration and operation of the wheel tread inspection device 10. As shown in FIG.

[0013] The vibration sensor 11 detects longitudinal wave vibrations and transverse wave vibrations among the vibrations transmitted through the rails on which the railway vehicle runs. The vibration sensor 11 is, for example, a sensor such as an acceleration sensor or a strain sensor, but is not limited to these. When vibration occurs on the rail and the vibration sensor 11 detects longitudinal wave vibrations and transverse wave vibrations, the vibration sensor 11 detects the longitudinal wave vibrations at a detection time t L , and the detection time t T to the wheel identification unit 12. Communication between the vibration sensor 11 and the wheel identification unit 12 may be via a dedicated network or a general-purpose network such as the Internet.

[0014] An example of the installation of the vibration sensor 11 will be described. FIG. 2 is a diagram showing an example of the installation of the vibration sensor 11 provided in the wheel tread inspection device 10 according to the first embodiment. Note that FIG. 2 shows only the wheels of a railway vehicle to make it easier to understand the positional relationship of each part. The rail on which the vibration sensor 11 is installed may be the rail on which the railway vehicle runs when in operation, or the rail on which the railway vehicle runs when not in operation, for example, the rail on which the railway vehicle runs when entering and leaving a rail depot. The vibration sensor 11 is installed on each of the two rails on which the railway vehicle runs, and is a biaxial sensor that detects longitudinal wave vibrations and transverse wave vibrations that propagate through the rails on each rail. Specifically, the vibration sensor 11 detects longitudinal wave vibrations and transverse wave vibrations that propagate through the rails using the two detection axes, the longitudinal wave detection axis and the transverse wave detection axis shown in FIG. 2.

[0015] In general, the speed at which longitudinal waves, which are compressional waves, travel is different from the speed at which transverse waves travel. For example, in steel, which is the material that makes up the rails on which railway vehicles run, the speed at which longitudinal waves travel, i.e., the transmission velocity v L is v L = 5.9 km / s, and the speed at which the transverse waves travel, i.e., the propagation velocity v T is v T = 3.2 km / s. The wheel identification unit 12, which will be described later, will use the difference between the transmission speeds of longitudinal waves and transverse waves. Furthermore, the accuracy with which the position of the peak of vibration transmitted through the rail is detected depends on the wavelength. The vibration caused by the impact of a flat, which is assumed in this embodiment, has a wide frequency band. Therefore, by using a high-frequency band with the vibration sensor 11, the wheel identification unit 12, which will be described later, can accurately determine the time when vibration occurred on the rail and the position on the rail where the vibration occurred.

[0016] When vibration occurs on the rail, the wheel identification unit 12 detects longitudinal wave vibration at the detection time t L and the detection time t when the vibration sensor 11 detects the vibration of the transverse wave. T from the vibration sensor 11. The wheel identification unit 12 acquires the detection time t Land the detection time t when the vibration sensor 11 detects the transverse wave vibration. T The wheel identification unit 12 obtains the position of the railway vehicle at the estimated time of occurrence from the railway vehicle position detection device 20. Based on the position of the railway vehicle at the time of occurrence, the wheel identification unit 12 identifies the wheel of the railway vehicle that was at the occurrence position at the time of occurrence as the wheel that caused the vibration.

[0017] A method by which the wheel identification unit 12 estimates the time when vibration occurs on the rail and the position on the rail where the vibration occurs will be described with reference to the drawings. FIG. 3 is a diagram for explaining a method by which the wheel identification unit 12 provided in the wheel tread inspection device 10 according to the first embodiment estimates the time when vibration occurs on the rail and the position on the rail where the vibration occurs. In FIG. 3, the installation position of the vibration sensor 11 is set to position 0 relative to the traveling direction of the railway vehicle (not shown), the position where vibration due to a wheel flat occurs is set to x, and the time when the vibration occurs is set to t0. If vibration occurs at position x at time of occurrence t0, the vibration sensor 11 detects the longitudinal wave at detection time t L is expressed by equation (1), and the detection time t T is expressed by equation (2).

[0018] t L =t0+|x| / v L …(1) t T =t0+|x| / v T …(2)

[0019] The detection time t when the vibration sensor 11 detects the longitudinal wave L and the detection time t when the vibration sensor 11 detects the transverse wave. T The difference between is expressed by equation (3).

[0020] t T -t L =(t0+|x| / v T )-(t0+|x| / v L )=(1 / v T-1 / v L )|x| …(3)

[0021] By using equations (1) to (3), the occurrence position |x| is expressed by equation (4), and the occurrence time t0 is expressed by equation (5).

[0022] |x|=(v L v T (t T -t L )) / (v L -v T ) …(4) t0=t L -|x| / v L =(v L t L -v T t T ) / (v L -v T ) …(5)

[0023] Although the formula (5) shows an example derived from the formula (1), the same result can be obtained by deriving it from the formula (2). L and the propagation velocity of the shear wave v T is a known value, the detection time t L and the detection time t when the vibration sensor 11 detects the transverse wave. T can be acquired, it is possible to calculate the time t0 at which vibration occurred on the rail and the position |x| on the rail at which the vibration occurred. The position on the rail at which the vibration occurred is expressed as an absolute value like |x| because the wheel identification unit 12 can calculate the time t0 at which vibration occurred on the rail and the position |x| on the rail at which the vibration occurred not only when the railway vehicle, i.e., the wheel, is approaching the vibration sensor 11 as shown in FIG. 3 but also when the railway vehicle, i.e., the wheel, is moving away from the vibration sensor 11. In this way, the wheel identification unit 12 can calculate the time t0 at which vibration occurred on the rail and the position |x| on the rail at which the vibration occurred, without being affected by the installation method of the vibration sensor 11, as long as the vibration is within a range in which the vibration sensor 11 can detect it.

[0024] The wheel identification unit 12 obtains the time t0 at which vibration occurred on the rail and the position |x| on the rail at which the vibration occurred, and then acquires the position of the railcar at the time t0 from the railcar position detection device 20. Here, the position of the railcar at the time t0 is assumed to be the leading position of the railcar. Note that, since the position of the vibration is |x|, the wheel identification unit 12 cannot determine whether the railcar is actually located x distance in front of the vibration sensor 11 or x distance past the vibration sensor 11. However, considering the range in which the vibration sensor 11 can detect vibrations, the actual length of the railcar, the operational interval between the leading and trailing railcars, and the like, the leading position of the railcar will not be located both x distance in front of the vibration sensor 11 and x distance past the vibration sensor 11. Therefore, the wheel identification unit 12 may use the leading position of the railcar that is located either x distance in front of the vibration sensor 11 or x distance past the vibration sensor 11. The communication between the wheel identification unit 12 and the railway vehicle position detection device 20 may be connected via a dedicated network or a general-purpose network such as the Internet.

[0025] The wheel identification unit 12 identifies the car number of the railway vehicle on which the wheel that caused the vibration is mounted and the position of the wheel on the railway vehicle with the corresponding car number, based on the difference between the leading position of the railway vehicle and the position |x| on the rail where the vibration occurred, taking into consideration the length of the railway vehicle, the positional relationship of the bogies on the railway vehicle that carry the wheels, etc. The position of the wheel on the railway vehicle with the corresponding car number may be identified, for example, as the third wheel from the front when the direction of travel is forward.

[0026] Because the wheel identification unit 12 can identify the wheel on the railway vehicle that has experienced a flat, railway vehicle maintenance personnel can obtain information about the wheel on which the flat occurred from the wheel identification unit 12 and, instead of inspecting all wheels on the railway vehicle in the same way, can focus inspection and repair on the wheel on which the flat occurred using the information about the wheel on which the flat occurred obtained from the wheel identification unit 12. In other words, by using the information obtained from the wheel identification unit 12, railway vehicle maintenance personnel can efficiently perform inspection and repair.

[0027] As a comparative example, the operation of determining the time t0 at which vibration occurs on the rail and the location x on the rail at which the vibration occurs will be described using the method described in Patent Document 1, which was described in the background of the present invention. FIG. 4 is a diagram for explaining the operation of determining the time t0 at which vibration occurs on the rail and the location x on the rail at which the vibration occurs, using the method described in Patent Document 1, which was described in the background of the present invention. In FIGS. 4(a) and 4(b), the position of vibration sensor 1 is designated as location 0, the position of vibration sensor 2 is designated as location X, the location at which vibration occurs due to a wheel flat is designated as location x, the time at which the vibration occurs is designated as location t0, and the transmission velocity, which is the speed at which the vibration travels through the rail, is designated as location v. Furthermore, the detection time at which vibration sensor 1 detects the vibration due to the wheel flat is designated as location t1, and the detection time at which vibration sensor 2 detects the vibration due to the wheel flat is designated as location t2.

[0028] In the example of FIG. 4(a) where a wheel of a railway vehicle is located between vibration sensor 1 and vibration sensor 2, the detection time t1 of vibration sensor 1 is expressed by equation (6), and the detection time t2 of vibration sensor 2 is expressed by equation (7).

[0029] t1=t0+x / v …(6) t2=t0+(Xx) / v …(7)

[0030] The difference between the detection time t1 when the vibration sensor 1 detects vibration and the detection time t2 when the vibration sensor 2 detects vibration is expressed by equation (8).

[0031] t2-t1=(Xx) / vx / v=X / v-2x / v …(8)

[0032] By using equations (6) to (8), the occurrence position x is expressed by equation (9), and the occurrence time t0 is expressed by equation (10).

[0033] x=-(v(t2-t1)-X) / 2 …(9) t0=t1+(v(t2-t1)-X) / 2v …(10)

[0034] On the other hand, in the example of Figure 4(b) where the wheels of the railway vehicle are not between vibration sensor 1 and vibration sensor 2, the detection time t1 of vibration sensor 1 is expressed by equation (11), and the detection time t2 of vibration sensor 2 is expressed by equation (12).

[0035] t1=t0+x / v …(11) t2=t0+(X+x) / v …(12)

[0036] The difference between the detection time t1 when the vibration sensor 1 detects vibration and the detection time t2 when the vibration sensor 2 detects vibration is expressed by equation (13).

[0037] t2-t1=(X+x) / vx / v=X / v …(13)

[0038] As shown in equation (13), in the example of FIG. 4(b), the difference between the detection time t1 when vibration sensor 1 detects vibration and the detection time t2 when vibration sensor 2 detects vibration depends only on X, the distance between vibration sensor 1 and vibration sensor 2, and the transmission speed v at which the vibration travels through the rail, and does not depend on the vibration occurrence position x, so the vibration occurrence position x cannot be calculated.

[0039] In contrast, the wheel tread inspection device 10 of this embodiment is not affected by the installation method of the vibration sensor 11, and can calculate the time t0 when vibration occurs on the rail and the position |x| on the rail where the vibration occurs, as long as the vibration is within the range that can be detected by the vibration sensor 11.

[0040] 5 is a flowchart showing the operation of the wheel tread inspection device 10 according to the first embodiment. In the wheel tread inspection device 10, the vibration sensor 11 detects longitudinal wave vibrations and transverse wave vibrations that are transmitted through the rail as vibrations caused by flats on the wheels of a railway vehicle running on the rail (step S11). The vibration sensor 11 detects longitudinal wave vibrations at a detection time t L and the detection time of the transverse wave vibration t T The wheel identifying unit 12 outputs the detection time t L and the detection time of the transverse wave vibration t T and the propagation velocity of the longitudinal wave v L and the propagation velocity of the shear wave v T Using these, the time t0 when the vibration occurred on the rail and the position |x| on the rail where the vibration occurred are calculated (step S13). The wheel identification unit 12 acquires the position of the railcar at the time t0 when the vibration occurred on the rail from the railcar position detection device 20 (step S14). From the difference between the leading position of the railcar and the position |x| on the rail where the vibration occurred, the wheel identification unit 12 identifies the position of the wheel that caused the vibration on the railcar, i.e., the car number of the railcar on which the wheel that caused the vibration is mounted and the position of the wheel on the railcar with the corresponding car number, taking into consideration the length of the railcar, the positional relationship of the bogies that carry the wheels on the railcar, etc. (step S15).

[0041] Next, the hardware configuration of the wheel tread inspection device 10 will be described. In the wheel tread inspection device 10, the vibration sensor 11 is a sensor such as an acceleration sensor or a strain sensor, as described above. The wheel identification unit 12 is realized by a processing circuit. The processing circuit may be a processor and memory that executes a program stored in memory, or may be dedicated hardware.

[0042] FIG. 6 is a diagram showing an example in which a processing circuit 90 that realizes the wheel tread inspection device 10 according to the first embodiment is configured with a processor 91 and a memory 92. When the processing circuit 90 is configured with the processor 91 and the memory 92, each function of the processing circuit 90 of the wheel tread inspection device 10 is realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in the memory 92. In the processing circuit 90, each function is realized by the processor 91 reading and executing the program stored in the memory 92. In other words, the processing circuit 90 includes the memory 92 for storing the program that results in the processing of the wheel tread inspection device 10 being executed. It can also be said that these programs cause a computer to execute the procedures and methods of the wheel tread inspection device 10.

[0043] The above program is configured such that when vibration occurs on the rail, the wheel identification unit 12 detects longitudinal wave vibration at the detection time t L and the detection time t when the vibration sensor 11 detects the transverse wave vibration. T and the wheel tread inspection device 10 executes an identification step of estimating the time t0 at which vibration occurred on the rail and the position |x| on the rail at which the vibration occurred from the difference between the time t0 and the position |x|, and identifying the wheel of the railway vehicle that was at the position |x| at the time of occurrence t0 as the wheel that caused the vibration, based on the position of the railway vehicle at the time of occurrence t0.

[0044] Here, the processor 91 may be a CPU (Central Processing Unit), a processing device, an arithmetic device, a microprocessor, a microcomputer, or a DSP (Digital Signal Processor), etc. Furthermore, the memory 92 may be, for example, a non-volatile or volatile semiconductor memory such as a RAM (Random Access Memory), a ROM (Read Only Memory), a flash memory, an EPROM (Erasable Programmable ROM), or an EEPROM (registered trademark) (Electrically EPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD (Digital Versatile Disc).

[0045] Fig. 7 is a diagram showing an example in which the processing circuit 93 that realizes the wheel tread inspection device 10 according to the first embodiment is configured with dedicated hardware. When the processing circuit 93 is configured with dedicated hardware, the processing circuit 93 shown in Fig. 7 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these. Each function of the wheel tread inspection device 10 may be realized by the processing circuit 93 separately for each function, or all functions may be realized collectively by the processing circuit 93.

[0046] It is also possible to implement some of the functions of the wheel tread inspection device 10 using dedicated hardware and some using software or firmware. In this way, the processing circuit can implement each of the above-described functions using dedicated hardware, software, firmware, or a combination of these.

[0047] As described above, according to this embodiment, in the wheel tread inspection device 10, the vibration sensor 11 detects longitudinal wave vibrations and transverse wave vibrations that are transmitted through the rail as vibrations caused by the wheels of a railway vehicle running on the rail. The wheel identification unit 12 detects the longitudinal wave vibrations at the detection time t L and the detection time t when the vibration sensor 11 detects the transverse wave vibration. T and calculates the time t0 when vibration occurred on the rail and the position |x| on the rail where the vibration occurred from the difference between |x| and |x|. The wheel identification unit 12 acquires the position of the railway vehicle at the time t0, and identifies the position of the wheel on the railway vehicle that caused the vibration from the difference between the front position of the railway vehicle and the position |x| on the rail where the vibration occurred. This allows the wheel identification unit 12 to inspect the tread abnormalities of the wheels of the railway vehicle within the range where the vibration sensor 11 can detect vibration, without being affected by the installation method of the vibration sensor 11. Furthermore, the wheel tread inspection device 10 does not need to arrange multiple sensors at intervals as in Patent Document 1 described in the background art, and therefore the device configuration can be made more compact.

[0048] In this embodiment, it is assumed that the wheel identification unit 12 pinpoints the position of the wheel that caused the vibration on the railway vehicle, but this is not limiting. If there is a possibility that errors may be included in the detection time by the vibration sensor 11, the transmission speed at which the vibration is transmitted through the rails, etc., the wheel identification unit 12 may identify a range that includes multiple wheels as the position of the wheel that caused the vibration on the railway vehicle, and output the information to a railway vehicle maintenance staff member or the like. Even in this case, the railway vehicle maintenance staff member can obtain information that is limited to a certain range, allowing them to efficiently perform inspections, repairs, etc.

[0049] Embodiment 2 In the first embodiment, the wheel identification unit 12 of the wheel tread inspection device 10 detects the longitudinal wave vibration detected by the vibration sensor 11 at the detection time t L and the detection time of the transverse wave vibration t TThe time t0 at which vibration occurred on the rail and the position |x| on the rail at which the vibration occurred were calculated using the above data. However, it is possible that the vibration sensor 11 may detect vibrations caused by factors other than the wheels of the railway vehicle. Even if data based on such vibrations is used, the wheel identification unit 12 cannot obtain information that is useful for railway vehicle maintenance, etc. Therefore, in the second embodiment, a method will be described in which the wheel identification unit 12 excludes noise other than tread abnormalities such as flat wheels of the railway vehicle.

[0050] Fig. 8 is a block diagram showing an example of the configuration of a wheel tread inspection system 30a according to embodiment 2. The wheel tread inspection system 30a includes a wheel tread inspection device 10a and a railway vehicle position detection device 20. The wheel tread inspection device 10a is configured by adding a memory unit 13 to the wheel tread inspection device 10 according to embodiment 1 shown in Fig. 1. The memory unit 13 stores the occurrence time t0 and occurrence position x of each vibration estimated by the wheel identification unit 12 when multiple vibrations occur on the rail.

[0051] In the second embodiment, the vibration sensor 11 performs the same operation as in the first embodiment every time vibration occurs on the rail.

[0052] In the second embodiment, the wheel identification unit 12 performs the same operation as in the first embodiment to calculate the occurrence time t0 at which the vibration occurred on the rail and the occurrence position x on the rail at which the vibration occurred, for each vibration detected by the vibration sensor 11. As shown in FIG. 9 (to be described later), the wheel identification unit 12 targets multiple vibrations detected by the vibration sensor 11, and can therefore determine whether a railway vehicle is approaching or moving away. Therefore, in the second embodiment, the occurrence position x does not need to be expressed as an absolute value. The same applies to the third embodiment (to be described later). The wheel identification unit 12 stores the occurrence time t0 and occurrence position x of each vibration calculated by calculation in the storage unit 13. Thereafter, when the wheel identification unit 12 plots the occurrence time t0 and occurrence position x of each vibration estimated when multiple vibrations occur on the rail, with the occurrence time t0 on the horizontal axis and the occurrence position x on the vertical axis, if the shape representing the characteristics of the arrangement of the plotted occurrence positions x forms a straight line, the wheel identification unit 12 determines that the cause of the vibration is an abnormality in the wheel tread that caused the vibration.

[0053] FIG. 9 is a diagram illustrating an example of the operation of the wheel identification unit 12 included in the wheel tread inspection device 10a according to the second embodiment. FIG. 9 is a diagram illustrating the occurrence time t0 and occurrence position x determined for each vibration by the wheel identification unit 12, plotted as described above with the occurrence time t0 on the horizontal axis and the occurrence position x on the vertical axis. When a flat occurs on the wheel tread of a railway vehicle, the vibration caused by the flat on the wheel tread will be detected by the vibration sensor 11 with each rotation of the wheel. Therefore, in FIG. 9, if the railway vehicle is traveling at a constant speed and approaching the vibration sensor 11, the vibration caused by the flat on the wheel tread will exhibit a linear transition in which the occurrence position x gradually approaches the vibration sensor 11 at regular time intervals, as shown in anomaly 1 and anomaly 2.

[0054] Therefore, the wheel identification unit 12 can determine that the vibration indicated by abnormality 1 is caused by the same factor and is based on an abnormality in the wheel tread. Similarly, the wheel identification unit 12 can determine that the vibration indicated by abnormality 2 is caused by the same factor, but is based on an abnormality in the wheel tread, but is a different factor from abnormality 1. On the other hand, the wheel identification unit 12 can determine that the vibration indicated by noise is not caused by an abnormality in the wheel tread, because there are no plots of vibrations arranged in a straight line, such as abnormality 1 and abnormality 2, in the preceding and following time periods.

[0055] FIG. 10 is a flowchart showing the operation of the wheel identification unit 12 included in the wheel tread inspection device 10a according to the second embodiment. The wheel identification unit 12 determines whether a shape characteristic of the arrangement of the plotted occurrence positions x is a straight line when the calculated occurrence time t0 at which vibration occurred on the rail and the occurrence position x on the rail at which the vibration occurred are plotted (step S21). If the shape is a straight line (step S21: Yes), the wheel identification unit 12 determines that the vibration is caused by an abnormality in the wheel tread (step S22). If the shape is not a straight line (step S21: No), the wheel identification unit 12 determines that the vibration is not caused by an abnormality in the wheel tread (step S23). The wheel identification unit 12 performs the operation of the flowchart shown in FIG. 10 between steps S13 and S14 of the flowchart shown in FIG. 5 described in the first embodiment. In the case of step S22, the wheel identification unit 12 proceeds to step S14 of the flowchart shown in FIG. 5, but in the case of step S23, the wheel identification unit 12 ends the operation without proceeding to step S14 of the flowchart shown in FIG. 5.

[0056] Here, in step S14, the wheel identification unit 12 acquires the position of the railway vehicle at the occurrence time t0 when vibration occurs on the rail from the railway vehicle position detection device 20, but in the second embodiment, there are multiple occurrence times t0 for one abnormality. However, since all occurrence times t0 relate to the same railway vehicle, the wheel identification unit 12 can acquire the position of the railway vehicle from the railway vehicle position detection device 20 using any of the multiple occurrence times t0, and therefore the occurrence time t0 to be used does not matter. The same applies to the third embodiment described below.

[0057] As mentioned above, FIG. 9 assumes that the railway vehicle is traveling at a constant speed. Therefore, even if a flat occurs on the wheel tread, if the railway vehicle is accelerating or decelerating, the occurrence position x will not be plotted in a straight line like abnormality 1 or abnormality 2 shown in FIG. 9. However, in a railway vehicle, it is easy to determine that the railway vehicle is accelerating or decelerating from the railway vehicle position and the railway vehicle position acquisition period acquired by railway vehicle position detection device 20. Therefore, even if the shape indicating the characteristics of the arrangement of the plotted occurrence positions x is not a straight line because the railway vehicle is accelerating or decelerating, if the shape indicating the characteristics of the arrangement of the plotted occurrence positions x becomes a straight line when it is assumed that the railway vehicle is traveling at a constant speed, wheel identification unit 12 may determine that the cause of the vibration is the abnormality in the wheel tread that caused the vibration.

[0058] 9 shows an example in which a railway vehicle approaches vibration sensor 11, but wheel identification unit 12 can perform the same operation even when a railway vehicle passes vibration sensor 11 and then moves away from vibration sensor 11. In this case, although not shown, abnormalities 1 and 2 shown in FIG. 9 will become larger in position with the passage of time, i.e., will be arranged in an upward sloping pattern. The same applies to embodiment 3 described below.

[0059] Furthermore, the wheel identification unit 12 has been described with reference to an example in which the occurrence time t0 and occurrence position x of each vibration estimated when vibrations occur multiple times on the rail are plotted, but this is not limiting. As long as the wheel identification unit 12 can grasp the relationship between anomaly 1, anomaly 2, and noise as shown in Fig. 9, the wheel identification unit 12 may make a determination assuming that the vibrations have been plotted, rather than actually plotting the occurrence time t0 and occurrence position x of each vibration. That is, when the wheel identification unit 12 plots the occurrence time t0 and occurrence position x of each vibration estimated when vibrations occur multiple times on the rail, with the occurrence time t0 on the horizontal axis and the occurrence position x on the vertical axis, the wheel identification unit 12 may determine that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations, if the shape representing the characteristics of the arrangement of the occurrence positions x becomes a straight line.

[0060] Regarding the hardware configuration of the wheel tread inspection device 10a, in the second embodiment, the storage unit 13 is a memory. The vibration sensor 11 and the wheel identification unit 12 are the same as those in the first embodiment.

[0061] As described above, according to this embodiment, in the wheel tread inspection device 10a, the wheel identification unit 12 determines that the cause of the vibration is an abnormality in the wheel tread that caused the vibration when the shape representing the characteristics of the arrangement of the plotted occurrence positions x for each vibration estimated for the occurrence time t0 and occurrence position x when multiple vibrations occur on the rail becomes a straight line. This allows the wheel identification unit 12 to exclude vibrations other than abnormalities in the wheel tread as noise. Because the wheel identification unit 12 can exclude noise, it can improve the accuracy of detecting vibrations caused by abnormalities in the wheel tread. Furthermore, because the wheel identification unit 12 can make determinations based on vibrations detected multiple times, even if, for example, one of the six vibrations shown as abnormality 1 in Figure 9 was not detected for some reason, it can accurately detect vibrations caused by abnormalities in the wheel tread by using the other vibrations that were detected.

[0062] Note that if the wheel identification unit 12 can store the occurrence time t0 and occurrence position x of each vibration estimated when multiple vibrations occur on the rail, that is, if the wheel identification unit 12 has the function of the memory unit 13, the wheel tread inspection device 10a can be configured without the memory unit 13. In this case, the wheel tread inspection device 10 of the first embodiment may be used in both the second embodiment and the second embodiment.

[0063] Embodiment 3 In the second embodiment, a case has been described in which the wheel identification unit 12 excludes vibrations other than those caused by abnormalities in the wheel tread as noise. However, vibrations periodically detected by the vibration sensor 11 may be vibrations caused by the rail in addition to vibrations caused by abnormalities in the wheel tread. Therefore, in the third embodiment, a method will be described in which the wheel identification unit 12 excludes vibrations caused by the rail.

[0064] In the third embodiment, the configuration of the wheel tread inspection system 30a is the same as the configuration of the wheel tread inspection system 30a in the second embodiment shown in FIG.

[0065] In the third embodiment, the vibration sensor 11 performs the same operation as in the first and second embodiments every time vibration occurs on the rail.

[0066] In the third embodiment, the wheel identification unit 12 calculates the occurrence time t0 at which the vibration occurred on the rail and the occurrence position x on the rail at which the vibration occurred for each vibration detected by the vibration sensor 11, using the same operations as in the first and second embodiments. The wheel identification unit 12 stores the occurrence time t0 and occurrence position x of each vibration calculated by the calculation in the storage unit 13. Thereafter, the wheel identification unit 12 plots the occurrence time t0 and occurrence position x of each vibration estimated when multiple vibrations occur on the rail, with the occurrence time t0 on the horizontal axis and the occurrence position x on the vertical axis. If the absolute value of the slope of the line indicating the characteristics of the arrangement of the plotted occurrence positions x is equal to or greater than a specified threshold, the wheel identification unit 12 determines that the cause of the vibration is an abnormality in the wheel tread that caused the vibration. If the absolute value of the slope of the line is less than the specified threshold, the wheel identification unit 12 determines that the cause of the vibration is due to the rail.

[0067] Fig. 11 is a diagram illustrating an image of the operation of the wheel identification unit 12 included in the wheel tread inspection device 10a according to the third embodiment. Fig. 11 is a diagram illustrating the occurrence time t0 and occurrence position x obtained by the wheel identification unit 12 for each vibration, plotted with the occurrence time t0 on the horizontal axis and the occurrence position x on the vertical axis, as described above. In Fig. 11, the vibrations indicated by abnormality 1, abnormality 2, and noise are the same as those in the example of Fig. 9 described in the second embodiment.

[0068] Rails on which railway vehicles run have joints between the rails. When long rails are used, the distance between the rail joints can be increased. Therefore, the influence of vibrations caused by the rail joints can be eliminated by positioning the vibration sensor 11 away from the rail joints. On the other hand, when long rails are used, it may be difficult to position the vibration sensor 11 in a location that is not affected by vibrations caused by the rail joints. However, once the vibration sensor 11 is installed, its installation position is not frequently changed, so the distance between the rail joints and the installation position of the vibration sensor 11 is constant. In other words, the occurrence position x of vibrations caused by rail joints is constant regardless of the occurrence time t0. Vibrations caused by abnormalities in the wheel treads progress linearly with a slope that depends on the traveling speed of the railway vehicle, as indicated by abnormality 1, abnormality 2, etc.

[0069] Therefore, the wheel identification unit 12 can determine whether the vibration is caused by an abnormality in the wheel tread or by the joint between the rails, based on the absolute value of the slope of the line that indicates the characteristics of the arrangement of the plotted occurrence positions x. The above-mentioned specified threshold value for determining the absolute value of the slope of the line can be determined, for example, taking into consideration the minimum speed set for the railway vehicle, but it may also be determined by other methods.

[0070] FIG. 12 is a flowchart showing the operation of the wheel identification unit 12 included in the wheel tread inspection device 10a according to the third embodiment. The wheel identification unit 12 determines whether a shape characteristic of the arrangement of the plotted occurrence positions x is a straight line when the calculated occurrence times t0 at which vibrations occurred on the rail and the occurrence positions x on the rail at which the vibrations occurred are plotted (Step S21). If the shape is not a straight line (Step S21: No), the wheel identification unit 12 determines that the vibration is not caused by an abnormality in the wheel tread (Step S23). If the shape is a straight line (Step S21: Yes), the wheel identification unit 12 determines whether the absolute value of the slope of the straight line is equal to or greater than a specified threshold (Step S31). If the absolute value of the slope of the straight line is equal to or greater than a specified threshold (Step S31: Yes), the wheel identification unit 12 determines that the vibration is caused by an abnormality in the wheel tread (Step S22). If the absolute value of the slope of the straight line is less than a specified threshold value (step S31: No), the wheel identification unit 12 determines that the vibration is caused by an abnormality in the rail (step S32). The wheel identification unit 12 performs the operation of the flowchart shown in Fig. 12 between steps S13 and S14 of the flowchart shown in Fig. 5 described in the first embodiment. In the case of step S22, the wheel identification unit 12 proceeds to step S14 of the flowchart shown in Fig. 5, but in the case of steps S23 and S32, the wheel identification unit 12 ends the operation without proceeding to step S14 of the flowchart shown in Fig. 5.

[0071] Although the wheel identification unit 12 has been described with reference to an example in which the occurrence time t0 and occurrence position x of each vibration estimated when multiple vibrations occur on the rail are plotted, the present invention is not limited to this. As long as the wheel identification unit 12 can grasp the relationships between anomaly 1, anomaly 2, noise, rail joints, and the like as shown in FIG. 11 , the wheel identification unit 12 may make a determination assuming that the occurrence time t0 and occurrence position x of each vibration have been plotted, rather than actually plotting the occurrence time t0 and occurrence position x of each vibration. That is, for the occurrence time t0 and occurrence position x of each vibration estimated when multiple vibrations occur on the rail, the wheel identification unit 12 may determine that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations if the absolute value of the slope of the line indicating the characteristics of the arrangement of the occurrence positions x plotted with the occurrence time t0 on the horizontal axis and the occurrence position x on the vertical axis is equal to or greater than a specified threshold, and may determine that the cause of the vibrations is due to the rail if the absolute value of the slope of the line is less than the threshold.

[0072] As described above, according to this embodiment, in the wheel tread inspection device 10a, the wheel identification unit 12 determines whether a vibration is caused by an abnormality in the wheel tread or by the rail, based on the absolute value of the slope of the line that indicates the characteristics of the arrangement of the plotted occurrence positions x for the occurrence time t0 and occurrence position x of each vibration periodically detected by the vibration sensor 11. This allows the wheel identification unit 12 to accurately extract vibrations caused by an abnormality in the wheel tread, even if the detection range of the vibration sensor 11 includes a joint between rails and the vibration sensor 11 detects vibrations caused by the joint between rails.

[0073] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0074] Various aspects of the present disclosure are summarized below as appendices.

[0075] (Appendix 1) a vibration sensor that detects longitudinal wave vibrations and transverse wave vibrations transmitted through rails on which railway vehicles run; a wheel identification unit that, when vibration occurs on the rail, estimates the time when vibration occurred on the rail and the position on the rail where the vibration occurred from the difference between the detection time when the vibration sensor detected the longitudinal wave vibration and the detection time when the vibration sensor detected the transverse wave vibration, and identifies the wheel of the railway vehicle that was at the generation position at the generation time as the wheel that caused the vibration to occur, based on the position of the railway vehicle at the generation time; A wheel tread inspection device comprising: (Appendix 2) When a shape representing the characteristics of the arrangement of the occurrence positions plotted with the occurrence time on the horizontal axis and the occurrence position on the vertical axis becomes a straight line, the wheel identification unit determines that the cause of the occurrence of the vibration is an abnormality in the wheel tread that caused the occurrence of the vibration, with respect to the occurrence time and the occurrence position of each vibration estimated when vibration occurs multiple times on the rail. 2. A wheel tread inspection device according to claim 1. (Appendix 3) When vibrations occur multiple times on the rail, the wheel identification unit determines that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations, when the absolute value of the slope of a straight line that indicates the characteristics of the arrangement of the occurrence positions plotted with the occurrence times on the horizontal axis and the occurrence positions on the vertical axis, is equal to or greater than a specified threshold value, and determines that the cause of the vibrations is attributable to the rail, when the absolute value of the slope of the straight line is less than the threshold value. 2. A wheel tread inspection device according to claim 1. (Appendix 4) moreover, a storage unit configured to store the occurrence time and the occurrence position of each vibration estimated by the wheel identification unit when vibrations occur multiple times on the rail; 4. A wheel tread inspection device according to claim 2 or 3, comprising: (Appendix 5) A wheel tread inspection device according to any one of appendices 1 to 4; a railway vehicle position detection device for detecting the position of a railway vehicle; A wheel tread inspection system comprising: (Appendix 6) The vibration sensor is a detection sensor that detects longitudinal wave vibrations and transverse wave vibrations among vibrations transmitted through rails on which railway vehicles run; an identification step in which, when vibration occurs on the rail, a wheel identification unit estimates the time when vibration occurred on the rail and the position on the rail where the vibration occurred from the difference between the detection time when the vibration sensor detected the longitudinal wave vibration and the detection time when the vibration sensor detected the transverse wave vibration, and identifies, based on the position of the railway vehicle at the time of occurrence, the wheel of the railway vehicle that was at the position of occurrence at the time of occurrence as the wheel that caused the vibration; A wheel tread inspection method comprising: (Appendix 7) In the identifying step, when vibrations occur multiple times on the rail, the wheel identifying unit determines that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations when a shape showing the characteristics of the arrangement of the occurrence positions plotted with the occurrence times on the horizontal axis and the occurrence positions on the vertical axis becomes a straight line for the occurrence times and the occurrence positions of each vibration estimated. 7. A wheel tread inspection method according to claim 6, (Appendix 8) In the identification step, when vibrations occur multiple times on the rail, the wheel identification unit determines that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations, if the absolute value of the slope of a straight line that shows the characteristics of the arrangement of the occurrence positions plotted with the occurrence time on the horizontal axis and the occurrence position on the vertical axis, for the occurrence time and the occurrence position of each vibration estimated, is equal to or greater than a specified threshold value, and determines that the cause of the vibrations is due to the rail, if the absolute value of the slope of the straight line is less than the threshold value. 7. A wheel tread inspection method according to claim 6, (Appendix 9) moreover, a storage step in which a storage unit stores the occurrence time and the occurrence position of each vibration estimated by the wheel identification unit when vibrations occur multiple times on the rail; 9. A wheel tread inspection method according to claim 7 or 8, comprising: [Explanation of symbols]

[0076] 10, 10a Wheel tread inspection device, 11 Vibration sensor, 12 Wheel identification unit, 13 Memory unit, 20 Railway vehicle position detection device, 30, 30a Wheel tread inspection system, 90, 93 Processing circuit, 91 Processor, 92 Memory.

Claims

1. a vibration sensor that detects longitudinal wave vibrations and transverse wave vibrations transmitted through rails on which railway vehicles run; a wheel identification unit that, when vibration occurs on the rail, estimates the time when vibration occurred on the rail and the position on the rail where the vibration occurred from the difference between the detection time when the vibration sensor detected the longitudinal wave vibration and the detection time when the vibration sensor detected the transverse wave vibration, and identifies the wheel of the railway vehicle that was at the generation position at the generation time as the wheel that caused the vibration to occur, based on the position of the railway vehicle at the generation time; A wheel tread inspection device comprising:

2. When a shape representing the characteristics of the arrangement of the occurrence positions plotted with the occurrence time on the horizontal axis and the occurrence position on the vertical axis becomes a straight line, the wheel identification unit determines that the cause of the occurrence of the vibration is an abnormality in the wheel tread that caused the occurrence of the vibration, with respect to the occurrence time and the occurrence position of each vibration estimated when vibration occurs multiple times on the rail.

2. The wheel tread inspection device according to claim 1.

3. When vibrations occur multiple times on the rail, the wheel identification unit determines that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations, when the absolute value of the slope of a straight line that indicates the characteristics of the arrangement of the occurrence positions plotted with the occurrence times on the horizontal axis and the occurrence positions on the vertical axis, is equal to or greater than a specified threshold value, and determines that the cause of the vibrations is attributable to the rail, when the absolute value of the slope of the straight line is less than the threshold value.

2. The wheel tread inspection device according to claim 1.

4. moreover, a storage unit configured to store the occurrence time and the occurrence position of each vibration estimated by the wheel identification unit when vibrations occur multiple times on the rail; 4. The wheel tread inspection device according to claim 2, further comprising:

5. A wheel tread inspection device according to any one of claims 1 to 3; a railway vehicle position detection device for detecting the position of a railway vehicle; A wheel tread inspection system comprising:

6. The vibration sensor is a detection sensor that detects longitudinal wave vibrations and transverse wave vibrations among vibrations transmitted through rails on which railway vehicles run; an identification step in which, when vibration occurs on the rail, a wheel identification unit estimates the time when vibration occurred on the rail and the position on the rail where the vibration occurred from the difference between the detection time when the vibration sensor detected the longitudinal wave vibration and the detection time when the vibration sensor detected the transverse wave vibration, and identifies, based on the position of the railway vehicle at the time of occurrence, the wheel of the railway vehicle that was at the position of occurrence at the time of occurrence as the wheel that caused the vibration; A wheel tread inspection method comprising:

7. In the identifying step, when vibrations occur multiple times on the rail, the wheel identifying unit determines that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations when a shape showing the characteristics of the arrangement of the occurrence positions plotted with the occurrence times on the horizontal axis and the occurrence positions on the vertical axis becomes a straight line for the occurrence times and the occurrence positions of each vibration estimated.

7. The wheel tread inspection method according to claim 6.

8. In the identification step, when vibrations occur multiple times on the rail, the wheel identification unit determines that the cause of the vibrations is an abnormality in the wheel tread that caused the vibrations, if the absolute value of the slope of a straight line that shows the characteristics of the arrangement of the occurrence positions plotted with the occurrence time on the horizontal axis and the occurrence position on the vertical axis, for the occurrence time and the occurrence position of each vibration estimated, is equal to or greater than a specified threshold value, and determines that the cause of the vibrations is due to the rail, if the absolute value of the slope of the straight line is less than the threshold value.

7. The wheel tread inspection method according to claim 6.

9. moreover, a storage step in which a storage unit stores the occurrence time and the occurrence position of each vibration estimated by the wheel identification unit when vibrations occur multiple times on the rail; 9. The wheel tread inspection method according to claim 7, further comprising:

Images