Rail condition monitoring device and rail condition monitoring method

Abstract

To discriminate a rail break from a rail joint.SOLUTION: A rail state monitoring device includes a plurality of detection devices provided in a train traveling on left and right railroad rails constituting a track, and a processing device. The train is an organization of one or more cars. For each of the plurality of detection devices, the detection device has a magnetic sensor part group consisting of one or more magnetic sensor parts facing the railroad rails, The magnetic sensor parts detect a peculiar place when the magnetic sensor parts pass on the peculiar place in the railroad rails, and the detection device outputs a signal based on a detection result by the magnetic sensor part group. The plurality of detection devices include detection devices provided on the train symmetrically in a right-and-left direction, and / or detection devices provided in front of and behind the train. The processing device receives a signal outputted from each of the plurality of detection devices, and determines whether the peculiar place is a rail joint place or a rail breakage place on the basis of a detection signal based on the signals from the plurality of detection devices.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to rail condition monitoring.

Background Art

[0002] A magnetic induction type rail flaw detector for detecting surface flaws and transverse cracks of a detection rail is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a railway track, there are joints between rails. Also, due to rail damage (especially transverse cracks) or other reasons, the rail may break. At the location of a rail joint or a rail break, at least a part of at least the rail surface is in a separated state in the longitudinal direction of the rail.

[0005] Although the magnetic induction type rail flaw detector described in Patent Document 1 can detect surface flaws and transverse cracks of the detection rail, it cannot distinguish between a rail break and a rail joint.

[0006] An object of the present invention is to distinguish between a rail break and a rail joint.

Means for Solving the Problems

[0007] To solve the above problems, one representative rail condition monitoring device of the present invention comprises a plurality of detection devices and a processing device installed on a train running on the left and right railway rails that constitute the track. The train is a formation of one or more cars. Each of the plurality of detection devices has a group of magnetic sensor units, which are one or more magnetic sensor units facing the railway rail. The magnetic sensor unit detects a specific location on the railway rail when the magnetic sensor unit passes over it, and the detection device outputs a signal based on the detection result by the group of magnetic sensor units. The plurality of detection devices include detection devices installed symmetrically on the left and right of the train, and / or detection devices installed at the front and rear of the train. The processing device receives signals output from each of the plurality of detection devices and, based on the detection signals from the plurality of detection devices, distinguishes whether the specific location is a rail joint or a rail fracture. [Effects of the Invention]

[0008] According to the present invention, rail fractures and rail joints can be distinguished.

[0009] Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of a rail condition monitoring device according to the first embodiment of the present invention. [Figure 2] This is a perspective view of the detection device in the first embodiment. [Figure 3] This is a bottom view of the detection device in the first embodiment. [Figure 4] This is a partially cutaway plan view of the detection device in the first embodiment. [Figure 5] This is a schematic diagram showing the operating state of the first embodiment. [Figure 6] This is a schematic diagram showing another operating state of the first embodiment. [Figure 7] This is a schematic diagram showing an example of the arrangement of detection devices. [Figure 8]It is a block diagram of a rail condition monitoring device according to the first embodiment. [Figure 9] It is a frequency characteristic diagram of an exciting current supplied to an oscillation coil. [Figure 10] It is a block diagram of a detection section. [Figure 11] It is a flowchart of a rail condition monitoring process. [Figure 12] It is a diagram showing an example of a display image displayed on a display section. [Figure 13] It is a block diagram of a rail condition monitoring device according to the second embodiment. [Figure 14] It is a block diagram of a rail condition monitoring device according to the third embodiment. [Figure 15] It is a schematic diagram showing an example of a joint location and a rail break location. [Figure 16] It is a diagram showing an example of a detection signal (time series waveform) regarding a joint location.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, several embodiments will be described with reference to the drawings. [First Embodiment] <External Configuration of the First Embodiment>

[0012] FIG. 1 is a schematic diagram of a rail condition monitoring device according to the first embodiment of the present invention.

[0013] In FIG. 1, a rail condition monitoring device 1 includes a detection device 2, a processing device 3, a connection cable 64, and a power source 111. The rail condition monitoring device 1 is mounted on each of one or more vehicles 200 (railway vehicles) in a train. The detection device 2 is installed at a position facing the tread surface 100a of the railway rail 100, and the processing device 3 and the power source 111 are installed inside the vehicle 200. The power source 111 supplies a driving current to the detection device 2 and the processing device 3 to operate the detection device 2 and the processing device 3.

[0014] The vehicle 200 travels on the railway rail 100 (hereinafter referred to as "rail 100") to be inspected. That is, the wheels 112 of the vehicle 200 rotate while in contact with the tread surface 100a. At that time, the detection device 2 detects the condition of the rail 100, and the signal resulting from the detection is sent to the processing device 3 via the connecting cable 64. The processing device 3 then performs processing such as signal acquisition, signal analysis, and display, enabling monitoring of the condition of the rail 100. The power supply 111 may be a stabilized power supply circuit driven by 100V AC installed inside the vehicle, or it may be an uninterruptible power supply with a built-in battery. In addition, objects called "ground beacons" may be embedded in the sleepers 500 of the rail 100, and objects called "on-board beacons" may be installed on the vehicle 200.

[0015] Figure 2 is a perspective view of the detection device 2. In the following description, when describing identical elements that are assigned a code consisting of a parent code and a branch code, the branch code will be omitted if any of the elements are acceptable, and the code consisting of a parent code and a branch code will be used when distinguishing between the elements.

[0016] In Figure 2, the detection device 2 comprises a lower housing 20 (an example of a first housing), an upper housing 26 (an example of a second housing), and a flange 25, all fixed to each other. The lower housing 20 and the upper housing 26 are formed in a substantially rectangular parallelepiped shape, and the upper surface of the lower housing 20 and the lower surface of the upper housing 26 are joined. The flange 25 is formed in a rectangular plate shape and is fixed to the upper surface of the upper housing 26. A connector 28 is attached to one side of the upper housing 26. A connector 62 is attached to one end of the connecting cable 64. Connectors 28 and 62 are matable, and when they are mated, the detection device 2 and the processing device 3 (see Figure 1) can communicate bidirectionally via the connecting cable 64. Connectors 28 and 62 have an airtight and waterproof structure, preventing water, oil, dust, etc. from entering the detection device 2 and the connecting cable 64 when they are mated. A pass-through connector is preferred for connector 28, but a non-pass-through connector may also be used.

[0017] Through holes 25a are formed at the four corners of the flange 25. The vehicle 200 (see Figure 1) is also provided with screw holes (not shown) at positions opposite the through holes 25a where the detection device 2 is to be placed. When a bolt (not shown) is inserted into the through hole 25a and tightened into the screw hole formed in the vehicle 200, the detection device 2 is fixed to the predetermined position on the vehicle 200. The lower housing 20 incorporates a group of magnetic sensor units 77 for detecting the state of the rail 100 (see Figure 1). The group of magnetic sensor units 77 is a collection of N magnetic sensor units. In this embodiment, N is an integer of 2 or more, but N may also be 1. The upper housing 26 incorporates a preamplifier unit 210 that amplifies the signals detected by each magnetic sensor unit in the group of magnetic sensor units 77. Details of the group of magnetic sensor units 77 and the preamplifier unit 210 will be described later.

[0018] As described above, the detection device 2 is fixed to a predetermined position on the vehicle 200. Preferably, this predetermined position is one in which the center line (not shown) in the width direction of the rail 100 coincides with the center line CL (see Figure 3) in the width direction of the magnetic sensor group 77. Preferably, the center line CL corresponds to the center of the detection device 2 (i.e., it is the center line in the width direction of the detection device 2). The internal spaces of the lower housing 20 and the upper housing 26 are filled with a filler (not shown) which is an insulating and non-magnetic material, forming a resin molded structure. This fixes and holds the magnetic sensor group 77 and the preamplifier 210 inside the lower housing 20 and the upper housing 26, preventing malfunctions of the magnetic sensor group 77 and the preamplifier 210 due to vibrations and shocks caused by vehicle movement, as well as displacement due to positional changes. In the example shown in Figure 2, the lower housing 20 and the upper housing 26 are roughly rectangular parallelepipeds, but their shapes may be other shapes such as cubes, cylinders, or prismatics.

[0019] Figure 3 is a bottom view of the detection device 2.

[0020] As shown in Figure 3, the magnetic sensor group 77 has N magnetic sensor units 21-1 to 21-N (in this embodiment, N is an integer of 2 or more as described above) arranged in a row along the width direction of the lower housing 20, that is, along the width direction of the rail 100 (see Figure 1).

[0021] Furthermore, the magnetic sensor unit 21-k (where k is any integer from 1 to N) includes an oscillation coil 5A-k, an oscillation coil 5B-k, and a receiving coil 6-k. Each of these coils is constructed by winding insulated copper wire.

[0022] The oscillation coil 5A-k, the receiving coil 6-k, and the oscillation coil 5B-k are arranged along the laying direction of the rail 100 (see Figure 1), and the receiving coil 6-k is positioned at equal intervals between the oscillation coils 5A-k and 5B-k. The oscillation coils 5A-k and 5B-k are supplied with an alternating current at a predetermined oscillation frequency f (predetermined frequency) from the processing device 3 (see Figure 1) via a connecting cable 64. As a result, alternating magnetic fields are generated from the oscillation coils 5A-k and 5B-k, respectively, exciting the rail 100, and the magnetic flux generated from the excited railway rail generates an induced voltage in the receiving coil 6-k.

[0023] Figure 4 is a partially cutaway plan view of the detection device 2. Specifically, in Figure 4, the central part of the flange 25 is cut out to expose the inside of the upper housing 26.

[0024] In Figure 4, the preamplifier section 210 includes an amplification filter section group 79, an acceleration sensor section 212, an angular velocity sensor section 214, a temperature sensor section 216, and a printed circuit board 210a on which these are mounted. The amplification filter section group 79 has the same number (N) of amplification filter sections 22-1 to 22-N as the magnetic sensor section 21 described above. The magnetic sensor section 21 and the amplification filter section 22 may correspond in a 1:1 ratio.

[0025] The amplification filter unit 22-k (where k is any integer from 1 to N) amplifies and filters the induced voltage generated in the receiving coil 6-k and transmits the result to the processing unit 3 via the connecting cable 64 (see Figure 1). The processing unit 3 analyzes the received signal and detects the magnetic signal generated from the railway rail 100.

[0026] The lower housing 20 is made of a non-magnetic material. This is because the lower housing 20 houses the oscillation coils 5A-k and 5B-k that generate an alternating magnetic field, and the receiving coil 6-k that detects the magnetic flux generated from the railway rails. In particular, considering that the detection device 2 is installed outdoors and under vehicle traffic, it is preferable to use a fiber-reinforced resin or the like, which has excellent impact resistance and environmental resistance, for the material of the lower housing 20.

[0027] On the other hand, the upper housing 26, which houses the preamplifier unit 210, is made of a metal such as aluminum that functions as an electromagnetic shield. This is to shield electromagnetic waves generated from the preamplifier unit 210 and to suppress electromagnetic waves that enter the preamplifier unit 210 from the outside. Furthermore, it is preferable that the upper housing 26 and the flange 25 be an integrated structure. That is, it is preferable to form the flange 25 and the upper housing 26 by machining a metal block. This improves the structural robustness of the flange 25 and the upper housing 26, and also reduces the number of components in the detection device 2.

[0028] The lower housing 20 is equipped with an insert nut (not shown) and is screwed to the upper housing 26. Furthermore, the lower housing 20 and the upper housing 26 are bonded together with a silicone adhesive that has excellent weather resistance, heat resistance, and cold resistance. In addition, by mounting the acceleration sensor unit 212 and the angular velocity sensor unit 214 on the printed circuit board 210a, the movement of the detection device 2 during the movement of the vehicle 200 can be captured.

[0029] Furthermore, by providing a temperature sensor unit 216 on the printed circuit board 210a, the temperature of the board can be monitored, allowing for constant confirmation of changes in the operating state due to heat generation in the amplification filter unit 22. Also, since the preamplifier unit 210 is sealed within the upper housing 26, the temperature detected by the temperature sensor unit 216 will be higher than the ambient temperature. Therefore, by pre-setting information representing the relationship between the ambient temperature and the temperature inside the upper housing 26 (for example, information that takes the temperature detected by the temperature sensor unit 216 as input and the ambient temperature as output (for example, a table or machine learning model)) in the processing unit 3, the processing unit 3 can use this information to estimate the ambient temperature during vehicle operation from the temperature detected by the temperature sensor unit 216.

[0030] The connecting cable 64 that connects the detection device 2 and the processing device 3 includes the power line of the preamplifier section 210, the output signal lines from each receiving coil 6-1 to 6-N (via the amplification filter section group 79), the input signal lines for the excitation signals to each oscillation coil 5A-1 to 5A-N and 5B-1 to 5B-N, and the output signal lines of the acceleration sensor section 212, the angular velocity sensor section 214, and the temperature sensor section 216. Therefore, it is preferable to use a multi-pair shielded cable with excellent noise immunity, such as a twisted-pair shielded cable, for the connecting cable 64. In addition, as a measure against crosstalk within the connecting cable 64, the connecting cable 64 may be divided into two cables. That is, one of the cables may be a multi-pair shielded cable that includes the power line of the preamplifier section 210 and the output signal lines of each receiving coil 6-k from the amplification filter section group 79. Alternatively, the other cable may be a separate multi-pair shielded cable containing input signal lines for excitation signals to each oscillation coil 5A-k and each oscillation coil 5B-k, and output signal lines for the acceleration sensor unit 212, the angular velocity sensor unit 214, and the temperature sensor unit 216.

[0031] Thus, it is preferable that the connection cable 64 consists of a total of two connection cables. The connection cable 64 is routed along the undercarriage of the vehicle 200 and connected to the processing device 3 through an inlet under the vehicle floor. The connection cable 64 is firmly fixed and held in place using metal cable ties or the like, so as not to interfere with the vehicle's operation, and so as not to become slack under the vehicle 200. Furthermore, it is preferable that the installation of the connection cable 64 from the detection device 2 to the processing device 3 is designed to minimize the cable length as much as possible and to avoid locations where electromagnetic noise is likely to be generated from the vehicle 200. <Principle of detecting anomalies such as rail fractures or joints>

[0032] Figure 5 is a schematic diagram showing the operating state of this embodiment. When current is supplied from the processing device 3 (see Figure 1), the oscillation coils 5A-k and 5B-k generate alternating magnetic fields with inverted phases at the same time. Specifically, the oscillation coils 5A-k and 5B-k are connected in series (or parallel) at the beginning or end of each winding of the insulated copper wire, and when an alternating voltage is applied from the processing device 3, they generate an alternating magnetic field. When the magnetic fluxes ΦA and ΦB generated from the oscillation coils 5A-k and 5B-k propagate to the tread surface 100a of the rail 100 (see Figure 1), a flow of magnetic flux is generated within the rail 100. Here, the direction of travel of the vehicle 200, which is the direction in which the detection device moves, is defined as the "x direction". Also, the direction in which the magnetic flux of the receiving coil 6-k is detected, that is, the direction of separation between the rail 100 and the detection device 2, is defined as the "y direction".

[0033] Figure 5 shows an example where there is no change in rail condition near the oscillation coils 5A-k, 5B-k, and receiving coil 6-k on rail 100. Here, an example where there is no change in rail condition means that there are no joints or that the rail is healthy with no breaks. The components of the magnetic flux linked to the receiving coil 6-k cancel each other out because the magnetic fluxes ΦA and ΦB are in opposite directions, and depend on the strength balance of the magnetic fluxes ΦA and ΦB. Therefore, when there is no change in rail condition, the magnetic flux linked to the receiving coil 6-k becomes almost zero, and the induced voltage of the receiving coil 6 also becomes almost zero.

[0034] Figure 6 is a schematic diagram showing other operating states of this embodiment.

[0035] Figure 6 shows an example where a singular location 102 is located near the oscillation coils 5A-k, 5B-k, and the receiving coil 6-k. Here, a singular location 102 refers to a location that has different magnetic properties from the normal rail 100. Specifically, singular locations 102 can be broadly classified into "joint locations" and "rail fracture locations." In other words, a singular location 102 is either a joint location or a rail fracture location.

[0036] The meanings of "x-direction" and "y-direction" in Figure 6 are the same as in Figure 5. In the illustrated example, the flow of magnetic flux generated within the rail 100 by the oscillating coils 5A-k and 5B-k is disturbed, causing magnetic flux leakage from the tread surface 100a of the rail 100. Therefore, when the receiving coil 6-k passes over the singular point 102, the induced voltage change of the receiving coil 6-k is larger than the induced voltage change in the case shown in Figure 5.

[0037] In this embodiment, the rail condition monitoring device 1 detects the generated leakage magnetic field based on the fact that the flow of magnetic flux generated on the railway rail 100, which is the object to be inspected, changes near the singular point 102. As an analytical model for this leakage magnetic field, the leakage magnetic field generated in space can be represented based on the dipole model. Here, as an example, let's consider the case in this model where the singular point 102 is a joint in the rail 100. In the leakage magnetic field component generated from the y direction of the rail 100, a two-polarity magnetic flux change appears with the center position of the joint as an inflection point, and with extreme values ​​(maximum and minimum values) in the x direction. <Distinguishing between joint locations and rail fracture locations>

[0038] In the example described above, we explained the case where the anomaly 102 is a "joint" in the rail 100, but detection can be performed similarly even if the anomaly 102 is a "rail fracture" in the rail 100. The principle is explained below. At a rail fracture in the rail 100, the rails are separated due to metal fatigue that occurs in the rail 100 as a result of vehicle operation. Therefore, when the detection device 2 passes over the rail fracture, the flow of magnetic flux ΦA and ΦB (see Figure 6) in the rail 100 is disturbed, similar to the detection of joints described above, and the detection device 2 can detect the presence of the rail fracture.

[0039] The joint and the rail break are similar in shape, where the rails are separated from each other.

[0040] Therefore, in this embodiment, the processing device 3 distinguishes whether the anomaly 102 is a joint or a rail break based on the disturbance in magnetic flux detected by the detection device 2. This discrimination utilizes an installation configuration in which the left and right rails 100 laid within the track are located in similar positions (symmetrical positions). That is, since the processing device 3 can monitor the condition of the left and right rails 100, if the detection signals from the left and right rails 100 show a bipolar magnetic flux change at the same time (or at the same point of travel), it determines that there is a rail joint. On the other hand, if a bipolar magnetic flux change occurs in the detection signal from one of the left or right rails 100, the processing device 3 determines that there is a rail break (see Figure 15).

[0041] In distinguishing between joints and rail fractures, the rails 100 within the track are laid regularly, resulting in joints existing at certain intervals (see Figure 15). The standard length of typical railway rails is 25m apart. In other words, if the rail condition monitoring device 1 detects that bipolar magnetic flux changes occur continuously at regular intervals from both the left and right rails 100 at the same time (or at the same point of travel), it is determined that a joint is present.

[0042] When the measurement time in the time-series data of the detection signal obtained by the rail condition monitoring device 1 (data representing the time series of detection signal intensity) is converted to the distance traveled by the vehicle 200, the distance between the poles in the bipolar magnetic flux change generated from the joint becomes a value similar to the distance between the centers of the oscillation coils 5A-k and 5B-k shown in Figure 6 (see reference numeral 1601 or 1602 in Figure 16). For example, if the diameters of the oscillation coils 5A-k, 5B-k and the receiving coil 6-k are 20 mm and the coils are arranged in close proximity to each other, the distance between the poles in the bipolar magnetic flux change generated from the joint becomes 40 mm. On the other hand, unlike joints, rail fractures have a significantly different distance between poles compared to joints because the separation intervals between rails are not uniform. Therefore, the processing unit 3 determines whether the distance between the extremes is the same as (including whether the difference is less than or equal to a predetermined difference) the distance between extremes for a joint (e.g., 2d) based on the coil diameter (e.g., d) and the arrangement of the oscillating coils 5A-k, 5B-k and the receiving coil 6-k. If this determination is true, the singular location is a joint. If this determination is false, the singular location is a rail fracture. Such discrimination is possible.

[0043] The gap between rails at joints in a railway track, which is the distance between rails, is sometimes adjusted according to the season to account for rail expansion and contraction due to temperature, but basically the gap is the same at all joints. On the other hand, rail fractures do not result in the artificial separation of rails like joints, but rather occur naturally due to metal fatigue, so the separated end faces of the rails are not uniform, and the condition of rail fractures is not the same at each location. In other words, with rail fractures, there are cases where the separation of rails is not uniform and even like at joints, such as when the rails are separated at an angle or when the separation is only partial.

[0044] The signals detected by the magnetic sensor units 21-1 to 21-N show a similar response at joint locations, regardless of the placement of the magnetic sensors. For example, the inter-pole signal intensity (peak-peak value) and inter-pole distance in the detection signal, which represents a change in two-polarity magnetic flux, are similar values ​​at each magnetic sensor unit 21. On the other hand, at rail break locations, due to the uneven separation of the rails, the inter-pole signal intensity (peak-peak value) and inter-pole distance are not similar values ​​at each magnetic sensor, resulting in variation. In other words, by monitoring the bias of the detection signals obtained at each magnetic sensor unit 21, it is possible to distinguish between joint locations and rail break locations.

[0045] Considering the risk of rail breakage occurring during vehicle operation, rail condition monitoring devices 1 are installed at the front and rear ends of vehicle 200. As shown in Figure 7, when a train is composed of multiple vehicles 200, for example, detection device 2a is installed on the leading vehicle 200a and detection device 2b is installed on the rear vehicle 200b (for example, rail condition monitoring devices 1 are installed on both vehicles 200a and 200b). With this installation configuration, rail breakage that occurs during vehicle operation can be identified from the difference in detection between the leading vehicle 200a and the rear vehicle 200b. That is, at joint locations, similar detection signals are obtained from both the leading vehicle 200a and the rear vehicle 200b. On the other hand, if no detection signal is obtained from the leading vehicle 200a but a detection signal is obtained from the rear vehicle 200b, it can be estimated that a rail break occurred during vehicle operation. <Circuit configuration of the first embodiment>

[0046] Figure 8 is a block diagram showing the overall configuration of the rail condition monitoring device 1 according to this embodiment.

[0047] As described above, the rail condition monitoring device 1 comprises a detection device 2, a processing device 3, and a power supply 111. The detection device 2 comprises magnetic sensor units 21-1 to 21-N and a preamplifier unit 210. The magnetic sensor unit 21-k comprises oscillation coils 5A-k and 5B-k and a receiving coil 6-k. The preamplifier unit 210 comprises amplification filter units 22-1 to 22-N, an acceleration sensor unit 212, an angular velocity sensor unit 214, and a temperature sensor unit 216. The amplification filter unit 22-k is connected to the magnetic sensor unit 21-k.

[0048] Furthermore, the processing unit 3 includes a resonant filter section 60-1 to 60-N, an amplification section 31-1 to 31-N, N-system digital-to-analog conversion section 32, an oscillation section 33, a detection section 34-1 to 34-N, an analog-to-digital conversion section 35, a memory section 36, and an evaluation device 4 (in this embodiment, N is an integer of 2 or more, but may be 1). The detection sections 34-1 to 34-N are sometimes collectively referred to as the "detection section group," and the resonant filter sections 60-1 to 60-N are sometimes collectively referred to as the "resonant filter section." The oscillation section 33 outputs a sinusoidal digital oscillation signal with a predetermined oscillation frequency f. The oscillation frequency f is selected to a value that can output a sufficient excitation magnetic field and ensure sufficient sensitivity of the receiving coil 6, taking into account the impedance of the oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N. Furthermore, when selecting the oscillation frequency f, it is preferable to give full consideration to the impact on the vehicle and railway track equipment. Specifically, in order to avoid affecting the operation of safety devices that support the safe operation of the vehicle, and the operation of track circuits that supply signal power to the railway rails for signal control, it is preferable to select a frequency range from 10kHz to 100kHz.

[0049] In Figure 8, the digital-to-analog conversion unit 32 converts the digital oscillation signal output by the oscillation unit 33 into an analog AC voltage. The amplification unit 31-k (where k is any integer from 1 to N) amplifies this AC voltage and applies it to the oscillation coils 5A-k and 5B-k in the magnetic sensor unit 21-k via the resonant filter unit 60-k. As a result, an AC magnetic field with inverted phase is generated from the oscillation coils 5A-k and 5B-k. The detection device 2 mounted on the vehicle 200 is spaced apart from the railway rail tread surface 100a (see Figure 1) so as not to interfere with the vehicle's movement. Therefore, an AC magnetic field of sufficient strength from the oscillation coil is required to adequately excite the railway rail. The resonant filter unit 60-k suppresses the inductance component of the oscillation coil at the oscillation frequency f (or a nearby frequency) set to match the oscillation coils 5A-k and 5B-k of the connected magnetic sensor unit 21-k, thereby reducing the impedance and increasing the strength of the AC magnetic field from the oscillation coil.

[0050] Figure 9 shows the frequency characteristics of the excitation current supplied to the oscillation coils 5A-k and 5B-k.

[0051] In Figure 9, characteristic L1 is the characteristic of this embodiment, and characteristic L2 is the characteristic when the resonant filter section 60-k is excluded. Furthermore, characteristic L1 is an example where the resonant frequency fc is 21 kHz. Comparing characteristics L1 and L2, it can be seen that characteristic L1 allows the excitation current at the resonant frequency fc to be set to more than six times that of characteristic L2, thereby increasing the strength of the AC magnetic field. Also, by optimizing the combination of the characteristics (DC resistance and inductance) of the oscillation coil 5 used and the resonant filter section 60, it is possible to make the excitation current of characteristic L1 at the resonant frequency fc more than 10 times greater than the excitation current of characteristic L2. It is preferable that this resonant frequency fc matches the oscillation frequency f in the oscillation section 33 (see Figure 8). Note that the resonant filter section 60-k is an LC resonant circuit equipped with a coil and a capacitor, and the oscillation coil 5 connected to it may be used as a coil for circuit configuration.

[0052] Returning to Figure 8, the amplification filter unit 22-k in the detection device 2 amplifies and filters the signal from the corresponding receiving coil 6-k, and transmits the result to the detection unit 34-k of the processing device 3. "Filtering" primarily refers to either low-pass filtering, which removes frequency components higher than the oscillation frequency f, or band-pass filtering, which allows only a specific frequency range centered around the oscillation frequency f to pass through. The detection unit 34-k uses the reference signal SR1 supplied from the oscillation unit 33 to generate signals X, Y, R, and θ (details of these signals will be described later) based on the signal supplied from the amplification filter unit 22-k, and supplies them to the analog-to-digital conversion unit 35. The analog-to-digital conversion unit 35 converts each analog signal received from the detection units 34-1 to 34-N into a digital signal.

[0053] Incidentally, in this embodiment, the vehicle 200 is also equipped with an inspection device 300 in addition to the rail condition monitoring device 1. The inspection device 300 supplies a position signal SD and a distance pulse signal SP to the rail condition monitoring device 1. These signals will now be described in detail.

[0054] Generally, railway systems are equipped with position detection systems. In this system, devices called "ground beacons" are embedded in the sleepers of the rails 100, and devices called "on-board beacons" are installed on the train 200. When an on-board beacon passes over a ground beacon, it detects it. Since the installation locations of the ground beacons are known, when an on-board beacon detects a ground beacon, the absolute position of the train 200 at that moment is determined. The position signal SD mentioned above is a signal that notifies the rail condition monitoring device 1 of this position information from the inspection device 300.

[0055] However, the ground beacons of the position detection system are often installed at intervals of several kilometers. Therefore, it is impossible to obtain the position information of the vehicle 200 in the section between ground beacons using only the position detection system. To address this, the processing unit 3 links the position information of the joints detected by the rail condition monitoring device 1 to the position information of the ground beacons, and calculates the absolute position information of the vehicle 200 from the detection data obtained when passing over the joints. In this process, the position of the joint first detected by the rail condition monitoring device 1 at the start of vehicle movement is used as the starting point for estimating the subsequent operating position of the vehicle. The inspection device 300 also detects the rotation angle of the wheels 112 (see Figure 1) of the vehicle 200, and outputs a one-shot distance pulse signal SP each time the wheels 112 rotate by a predetermined angle. The analog-to-digital conversion unit 35 then converts the position signal SD and the distance pulse signal SP into digital signals and stores them in the memory unit 36. The digital signals output from the analog-to-digital conversion unit 35 are stored as data in the memory unit 36 ​​and supplied to the evaluation device 4. Then, after the inspection device 300 outputs a position signal SD related to a ground beacon, the rail condition monitoring device 1 counts distance pulse signals SP, and based on the position of the ground beacon, it can estimate the current position of the vehicle 200. By combining this with the distance information obtained from the distance pulse signals and the vehicle's running speed between each joint detected by the rail condition monitoring device 1, it becomes possible to estimate the vehicle's operating position during travel with high accuracy.

[0056] Next, we will describe evaluation device 4. Evaluation device 4 is equipped with typical computer hardware such as a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and HDD (Hard Disk Drive). The HDD stores the OS (Operating System), application programs, and various data. The OS and application programs are loaded into RAM and executed by the CPU.

[0057] The evaluation device 4 comprises a control unit 42, a data processing unit 43, an output processing unit 44, an operation input unit 45, a display unit 46, and a storage unit 47. Based on the rail condition monitoring data received from the detection device 2, the detection units 34-1 to 34-N, the analog-to-digital conversion unit 35, and the memory unit 36, the evaluation device 4 executes an inspection processing program to identify the anomaly 102 (see Figure 6) of the rail 100. In this embodiment, "rail condition monitoring data" refers to the data from all stages from the receiving coil 6 of the detection device 2 to the evaluation device 4.

[0058] The control unit 42 is, for example, a CPU (an example of a processor) and controls the reading of inspection data from the memory unit 36 ​​and arithmetic processing. The data processing unit 43 performs inspection processing based on the inspection data (details will be described later). The display unit 46 is an LCD (Liquid Crystal Display), CRT (Cathode Ray Tube) display, etc., that displays inspection results, etc. The output processing unit 44 causes the display unit 46 to display the results of rail condition monitoring, etc. At that time, the output processing unit 44 performs processing to display the information in a visually easy-to-understand format, using graphs or tables as appropriate. The operation input unit 45 is an information input means such as a keyboard or mouse. The storage unit 47 stores the inspection results and other data processed by the data processing unit 43. Data stored in the memory unit 36 ​​is also transferred to the storage unit 47. The data processing unit 43 and the output processing unit 44 are realized by loading programs and data stored in the storage unit 47 into the control unit 42 and executing arithmetic processing.

[0059] Figure 10 is a block diagram of the detection unit 34-k. The received signal SS from the amplification filter unit 22-k is supplied to phase comparators 74 and 76. The reference signal SR1 supplied from the oscillation unit 33 (see Figure 7) is delayed by the delay circuit 72 for a time corresponding to a 90° phase of the oscillation frequency f. The delayed reference signal SR1 is called reference signal SR2. Reference signal SR1 is supplied to phase comparator 76, and reference signal SR2 is supplied to phase comparator 74. Phase comparator 76 extracts the component in the received signal SS that is synchronized with reference signal SR1. The extracted signal is filtered by an LPF (low-pass filter) 80, and the LPF 80 outputs the processing result as a cosine signal X.

[0060] Furthermore, the phase comparator 74 extracts the component in the received signal SS that is synchronized with the reference signal SR2. The extracted signal is filtered by the LPF 78, which outputs the result as a sine signal Y. The arithmetic unit 84 calculates √(X 2 +Y 2 The arithmetic unit 82 calculates the arctangent of (Y / X), i.e., atan(Y / X), and outputs the result as the phase difference signal θ.

[0061] The detection unit 34-k then supplies the aforementioned signals X, Y, R, and θ to the memory unit 36 ​​via the analog-to-digital conversion unit 35 (see Figure 8). In the illustrated example, the detection unit 34-k outputs all of the signals X, Y, R, and θ, but the amplitude signal R and phase difference signal θ may be calculated by the data processing unit 43 (see Figure 8) based on the cosine signal X and sine signal Y, rather than being calculated by the detection unit 34-k.

[0062] Here, let's explain why the detection unit 34-k detects a sine signal Y in addition to the cosine signal X. First, if we prioritize the cosine signal X, we can consider setting the phase of the reference signal so that the amplitude of the cosine signal X is maximized. In that case, this set phase can be said to be the optimal phase for detecting the cosine signal X. However, the received signal SS is independent for each magnetic sensor unit 21-1 to 21-N, and the placement and manufacturing tolerances differ for each magnetic sensor unit 21-1 to 21-N. Furthermore, the optimal phase also changes due to aging and temperature changes. Therefore, setting the optimal phase of the reference signal for each of the detection units 34-1 to 34-N is complicated.

[0063] The sine signal Y is a signal component whose phase is shifted by 90° relative to the excitation magnetic field that energizes the rail. As in this embodiment, when the sine signal Y is detected together with the cosine signal X, the arithmetic unit 84 (or evaluation device 4) can calculate the amplitude signal R. In principle, the value of the amplitude signal R remains constant even when the phase difference signal θ fluctuates, so the process of optimizing the phase of the reference signal can be omitted.

[0064] In Figure 16, the signal indicated by symbol 1602 is an example of a cosine signal X or a sine signal Y. The signal indicated by symbol 1601 is an example of an amplitude signal R. <Operation of the first embodiment>

[0065] Figure 11 is a flowchart of the rail condition monitoring process performed by the data processing unit 43 of the evaluation device 4.

[0066] This process is executed at predetermined control cycles. In Figure 11, steps S2, S12, and S14 are executed in parallel. First, in step S2, the evaluation device 4 acquires rail condition monitoring data from the storage unit 47, in step S12, it acquires a position signal SD from the storage unit 47, and in step S14, it acquires a distance pulse signal SP from the storage unit 47. After step S14 is completed, in step S16, the evaluation device 4 converts the distance pulse signal SP into distance data SK. That is, the evaluation device 4 calculates the distance data SK based on the number of times the distance pulse signal SP has been detected since the last time the position detection system detected a ground beacon. Here, the distance data SK refers to the distance from a predetermined reference position, and the distance data SK is just one example of position data.

[0067] Furthermore, after step S2 is completed, in step S4, the evaluation device 4 determines whether the predetermined inspection data falls outside a predetermined reference range, i.e., the range in which a "joint location" can be estimated. Here, the "predetermined inspection data" is, for example, the amplitude signal R shown in Figure 10. When the anomaly location 102 (see Figure 6) is a structure, the amplitude signal R is clearly larger compared to when the anomaly location 102 is a predicted abnormality location. Therefore, in step S4, the evaluation device 4 compares the amplitude signal R with a predetermined threshold Rth1. If "R ≠ Rth1", it may be determined to be "Yes", meaning there is a possibility of a joint location or rail fracture location. On the other hand, if "R = Rth1" (which may include the difference being less than or equal to a predetermined difference), it may be determined to be "No", meaning there is neither a joint nor a rail fracture.

[0068] If the result is "No" at this point, the process proceeds to step S18. The details of this process will be described later. On the other hand, if the result is "Yes" in step S4, the process proceeds to step S10. In step S10, joints and fractures are distinguished based on the signals X, Y, R, and θ shown in Figure 10. During this discrimination, the evaluation device 4 also uses the position signal SD acquired in step S12. This allows the system to identify the last detected ground beacon and the next ground beacon expected to be detected. Therefore, if a rail fracture is identified during the discrimination process, the location of the rail fracture is located in the section between those ground beacons.

[0069] When the processing in steps S2 to S16 described above is completed, the process proceeds to step S18, where the rail condition monitoring result is generated. Here, the "rail condition monitoring result" may include a correspondence between anomalies (joint locations and rail fracture locations) and distance data SK if step S10 has been performed (if step S10 has not been performed, the "rail condition monitoring result" may include a result indicating no anomalies). Next, when the process proceeds to step S20, the data processing unit 43 outputs the rail condition monitoring result to the display unit 46, etc., and the processing of this routine is completed.

[0070] Figure 12 shows an example of the display image 120 displayed in the display unit 46 in step S20 described above.

[0071] Display image 120 includes a railway rail image 140 and multiple alert display objects 130. The railway rail image 140 schematically displays the rail 100. The alert display objects 130 are displayed at locations corresponding to joints and rail fractures. The alert display object 130 includes the string "Alert", a structure type display object 134, and a location display object 136.

[0072] Here, the structure type display object 134 is a string representing the type of "joint" or "rail fracture." The position display object 136 is a number representing the distance from a predetermined reference position to the structure. By displaying the rail condition monitoring results on a GUI (Graphical User Interface) screen in this way, the user can visually and clearly understand where joints and rail fractures exist on the rail 100.

[0073] In the example shown in Figure 12, the structure type display object 134 included in the alert display object 130 is the string "joint" and "rail fracture," but it may also be a corresponding mark. Furthermore, identification information (tags) indicating whether it is a joint or a rail fracture may be associated with the specific location. This makes it possible to manage the section between joints on a rail-by-rail basis, or to manage which rail 100 has a rail fracture. Of the display objects representing joints and display objects representing rail fractures, only the display object representing joints may be displayed. This makes it possible to manage the number of joints present in the section of travel for vehicle 200.

[0074] Furthermore, if the detected information represents a "joint," significant changes will appear in the signals X, Y, R, and θ shown in Figure 10, depending on the amount of gap at the joint (the distance between the rails). Therefore, if the detected information represents a "joint," the evaluation device 4 calculates the amount of gap at the joint based on the signals X, Y, R, and bθ, stores the calculated amount of gap in association with the aforementioned tag (identification information), and can display its contents. Also, if the detected anomaly location 102 is a rail fracture location, the evaluation device 4 can store the signals X, Y, R, and θ at the anomaly prediction location in association with the aforementioned tag (identification information), and can display its contents.

[0075] Thus, tagged rail condition monitoring results are useful for checking for abnormalities in the track due to rail breaks and for checking the amount of slack. For example, locations where abnormalities are extracted from the time-series data of signals X, Y, R, and θ between tagged specific locations can be identified as locations where rail breaks are presumed to have occurred, allowing users to perform detailed on-site checks. Furthermore, since the evaluation device 4 can identify the rail joint locations, it is possible to know in advance the correlation between the amount of change in the time-series data of the target signal obtained at the joints and the amount of slack. This makes it possible to extract the amount of slack at all joints in the running section during vehicle operation. Here, the amount of slack is affected by the outside temperature, and the optimal state differs depending on the season (summer, winter). Therefore, by correcting the temperature information obtained by the temperature sensor unit 216 included in the detection device 2 to the outside temperature during vehicle operation, this temperature information can be used for managing the amount of slack by the rail condition monitoring device 1. Furthermore, since this rail condition monitoring device can be used while a vehicle is running, it can contribute to efficient rail maintenance management by calculating the difference in acquired data for each running day (inspection day), thereby capturing the condition of the rails in the running section (occurrence of rail fractures, changes in the amount of play, etc.) and determining the timing and location of rail maintenance. <Effects of the First Embodiment>

[0076] As described above, the rail condition monitoring device 1 of this embodiment comprises a lower housing 20 and an upper housing 26. The lower housing 20 houses the magnetic sensor units 21-1 to 21-N and is made of a non-magnetic material. The upper housing 26 houses the preamplifier unit 210 and is fixed to the upper surface of the first housing 20. A connector 28 connected to a connecting cable 64 is attached to one side of the upper housing 26. The upper housing 26 is made of metal. This allows for accurate detection of the rail condition 100.

[0077] Furthermore, the detection device 2 energizes the tread surface 100a of the rail 100 with an alternating magnetic field and detects anomalies 102 on the tread surface 100a of the rail 100 based on disturbances in the flow of magnetic flux generated in the rail 100. This makes it possible to detect the condition of the railway rail more accurately based on disturbances in the flow of magnetic flux generated in the rail 100.

[0078] The rail condition monitoring device 1 further includes an oscillating coil 5A-k that generates an alternating magnetic field to excite the rail 100, and a resonant filter section 60-k connected to the oscillating coil 5A-k. The resonant filter section 60-k and the oscillating coil 5A-k have resonant frequencies corresponding to the frequency of the alternating magnetic field. This allows the strength of the alternating magnetic field to be increased, enabling more accurate detection of the condition of the railway rails.

[0079] Furthermore, the rail condition monitoring device 1 also includes an output processing unit 44. The output processing unit 44 displays the type and location of the detected anomaly 102 as an image on the display unit 46. This allows the user to visually understand the condition of the rail 100.

[0080] Furthermore, the evaluation device 4 can manage each rail 100 using identification information associated with the anomaly location 102 (identification information of the type of anomaly location 102) based on the discrimination results for the anomaly location 102.

[0081] Furthermore, if the evaluation device 4 determines that the detected anomaly 102 is a joint in the rail 100, it calculates the amount of gap in the joint based on the turbulence of the magnetic flux flow. This allows the rail condition monitoring device 1 to appropriately manage the amount of gap in the joint.

[0082] Furthermore, the evaluation device 4 collects inspection data for each inspection day, which includes at least the type of anomaly 102 (joints and rail fractures), the number of anomalies 102, the location of the anomalies 102, information indicating the occurrence of rail fractures, and the amount of joint clearance. By calculating the difference in inspection data between different inspection days, the device monitors the changes in the state of the rail 100. This allows for accurate monitoring of changes in the state of the rail 100 based on the difference in inspection data between different inspection days.

[0083] Furthermore, the rail condition monitoring device 1 of this embodiment is equipped with a group of detection units 34-1 to 34-N that detect a first detection signal X corresponding to the first phase (0°) of the output signal and a second detection signal Y corresponding to the second phase (90°) of the output signal, respectively, for each output signal output from the receiving coil. This allows for accurate detection of specific locations on the rail 100.

[0084] Furthermore, multiple detection units 34-1 to 34-N output a first detection signal X, a second detection signal Y, or the result R and / or θ obtained by performing calculations on the first detection signal X and the second detection signal Y. The processing unit 3 determines the presence and type of anomalies from the time-series data of signals X, Y, R and / or θ corresponding to the multiple magnetic sensor units 21-1 to 21-N. Based on the position signal SD and distance pulse signal SP from the inspection device 300 installed in the vehicle 200, the processing unit 3 detects the location of the anomaly and displays the result on the display unit 46.

[0085] Here, by displaying the location and position of anomalies on the rail 100 on a GUI screen, users can more accurately recognize anomalies on the railway rail. The position signal SD is obtained when a sensor mounted on the vehicle (on-board sensor) and a sensor installed near the laid rail (ground sensor) react during operation. Since it is difficult to install ground sensors so that the location of all anomalies on the rail 100 can be identified, there is a limit to the position information of anomalies obtained by the position signal SD. In addition, malfunctions of ground sensors due to outdoor installation, responses from on-board sensors that are detached from the ground sensor, and responses to ground sensors in the section of the opposing vehicle can affect the accuracy of anomaly detection. According to the rail condition monitoring device 1 of this embodiment, anomalies on the tread surface 100a of the rail 100 can be detected using a detection device 2 mounted on the underside of the vehicle, and the accuracy of the detected position can be maintained. [Second Embodiment]

[0086] Next, a second embodiment of the present invention will be described. In the following description, parts corresponding to each part in Figures 1 to 12 will be denoted by the same reference numerals, and their descriptions may be omitted. Furthermore, the following description will mainly focus on the differences from the first embodiment, and the similarities with the first embodiment will be omitted or simplified. <Configuration of the second embodiment>

[0087] Before describing the configuration of this embodiment, let us reconsider the first embodiment described above. As explained in Figure 5, if there are no special locations such as structures on the rail 100, the components of magnetic flux ΦA and ΦB that link with the receiving coil 6-k cancel each other out, and the linked magnetic flux is ideally zero. Therefore, the output voltage of the receiving coil 6-k is ideally zero.

[0088] However, if there is a difference in the shape (inner diameter, outer diameter, coil length, etc.) of the oscillation coils 5A-k and 5B-k, the magnetic fluxes ΦA and ΦB generated by them will not cancel each other out in the receiving coil 6-k, and a noise signal of the same frequency as the oscillation signal will be continuously output from the receiving coil 6-k. By increasing the machining precision of the oscillation coils 5A-k and 5B-k sufficiently, it is expected that this noise signal can be reduced to a level that does not pose a practical problem, but it is preferable that the noise signal can be reduced even if the machining precision is not high. Therefore, this embodiment aims to reduce the required machining precision of the oscillation coils 5A-k and 5B-k by electrically canceling the noise signal.

[0089] Figure 13 is a block diagram showing the overall configuration of the rail condition monitoring device 1a according to a second embodiment of the present invention.

[0090] The external configuration of the rail condition monitoring device 1a in this embodiment is the same as that of the first embodiment (see Figures 1 to 4). The configurations of the detection device 2 and the evaluation device 4 are also the same as those of the first embodiment (see Figure 8). However, in this embodiment, the processing device 3a is used instead of the processing device 3 of the first embodiment.

[0091] In the processing unit 3a, correction signal generation units 50-1 to 50-N and subtraction units 52-1 to 52-N are provided, corresponding to the amplification filter units 22-1 to 22-N. The correction signal generation units 50-1 to 50-N are collectively referred to as the correction signal generation unit group, and the subtraction units 52-1 to 52-N are collectively referred to as the subtraction unit group. As described above, a noise signal with oscillation frequency f is superimposed on the induced voltage output by the magnetic sensor unit 21-k, and this noise signal is amplified in the amplification filter unit 22-k. The correction signal generation unit 50-k attempts to generate a correction signal having approximately equal amplitude and phase to the noise signal in order to cancel this noise signal. That is, this amplitude and phase are preset in the correction signal generation unit 50-k according to the characteristics of the magnetic sensor unit 21-k.

[0092] Then, the subtraction unit 52-k cancels the noise signal by subtracting the correction signal from the output signal of the amplification filter unit 22-k. As a result, the detection units 34-1 to 34-N are supplied with signals from which the noise signal has been canceled. The configuration of the processing unit 3a other than those described above is the same as that of the processing unit 3 of the first embodiment (see Figure 8).

[0093] According to this embodiment, even if the machining accuracy of the oscillation coils 5A-k and 5B-k is low, the noise signal can be electrically canceled, and the unique location of the rail 100 can be detected with high accuracy. [Third Embodiment]

[0094] Next, a third embodiment of the present invention will be described. In the following description, parts corresponding to each part in Figures 1 to 13 will be denoted by the same reference numerals, and their descriptions may be omitted. Furthermore, the following description will mainly focus on the differences from the first and second embodiments, and the similarities with the first and second embodiments will be omitted or simplified in its explanation.

[0095] Figure 14 is a block diagram showing the overall configuration of the rail condition monitoring device 1b according to the third embodiment of the present invention. The external configuration of the rail condition monitoring device 1b in this embodiment is the same as that of the first embodiment (see Figures 1 to 4). The configuration of the detection device 2 and the evaluation device 4 is also the same as that of the first embodiment (see Figure 8). However, in this embodiment, the processing device 3b is used instead of the processing device 3 of the first embodiment.

[0096] The processing unit 3b of this embodiment includes a signal adjustment unit 70, a digital-to-analog conversion unit 32a, amplification units 31A-1 to 31A-N and 31B-1 to 31B-N, and resonant filter units 60A-1 to 60A-N and 60B-1 to 60B-N. Furthermore, in the first and second embodiments described above, the oscillation coils 5A-k and 5B-k were connected in series (or parallel), but in this embodiment, the oscillation coils 5A-k and 5B-k are not connected to each other and are independent. The signal adjustment unit 70 adjusts the amplitude and phase of 2N digital oscillation signals. That is, the signal adjustment unit 70 adjusts the amplitude and phase of the digital oscillation signals output from the oscillation unit 33, corresponding to each of the 2N oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N.

[0097] Furthermore, the digital-to-analog conversion unit 32a converts the adjusted 2N digital oscillation signals into analog signals. The 2N amplification units 31A-1 to 31A-N and 31B-1 to 31B-N amplify the 2N analog signals. In addition, the 2N resonant filter units 60A-1 to 60A-N and 60B-1 to 60B-N suppress the inductance components of the 2N oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N to reduce their impedance and increase the strength of the AC magnetic field from the oscillation coils. The signal adjustment unit 70 described above adjusts the output balance of the oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N so that the output voltage of the receiving coils 6-1 to 6-N approaches zero as closely as possible when no singularity 102 (see Figure 6) exists. The configuration of the processing unit 3b other than those described above is the same as that of the processing unit 3 of the first embodiment (see Figure 7).

[0098] According to this embodiment, the alternating magnetic fields from the oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N entering the receiving coils 6-1 to 6-N can be canceled out, and the balanced output of the magnetic sensor section 21-1 to 21-N can be supplied to the detection section 34-1 to 34-N. As a result, the system gain in the amplification filter section 22-1 to 22-N and the detection section 34-1 to 34-N can be increased, and the detection capability of the receiving coils 6-1 to 6-N can be improved. [Differentiation]

[0099] The present invention is not limited to the embodiments described above, and various modifications are possible. The embodiments described above are illustrative examples provided to facilitate understanding of the present invention, and are not necessarily limited to those comprising all the described configurations. Furthermore, it is possible to replace parts of the configuration of one embodiment with those of another embodiment, and to add configurations from other embodiments to the configuration of one embodiment. It is also possible to delete parts of the configuration of each embodiment, or to add and / or replace other configurations. In addition, the control lines and information lines shown in the figures are those considered necessary for illustrative purposes and do not necessarily represent all control lines and information lines required in the product. In practice, it can be assumed that almost all configurations are interconnected. Possible modifications to the above embodiments are as follows, for example. (1) Since the hardware of the evaluation device 4 in each of the above embodiments can be implemented by a general-purpose computer, the program for executing the processes related to the flowchart shown in Figure 11 may be installed on the computer from a program source such as a portable storage medium or server. (2) The functions shown in Figures 8, 13, and 14, and the processes described based on Figure 11, etc., were described in the above embodiment as functions and processes realized by the execution of a program by the processor, but some or all of them may be replaced with hardware functions and processes using an ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array), etc. (3) In each of the above embodiments, the rail condition monitoring device 1 may be mounted on any type of railway vehicle, including electric trains (for example, conventional trains or Shinkansen trains) or diesel locomotives used for inspections. (4) The processing unit 3 may use a GNSS position signal obtained by a GNSS (Global Navigation Satellite System) system installed in the vehicle 200, in place of or in addition to the position signal SD and the distance pulse signal SP, to detect the position of the anomaly 102.

[0100] The above explanation can be summarized as follows, for example. The following summary may include explanations of supplementary information or variations of the above explanation. In the following explanation, the width direction of the track is the "left-right" direction, and the longitudinal direction of the track is the "front-back" direction.

[0101] The rail condition monitoring device (1, 1a, 1b) comprises a detection device (2) installed on a train running on the left and right railway rails (100) that constitute the track, and a processing device (3, 3a, 3b). The train is a formation of one or more cars (200).

[0102] The detection device has a group of magnetic sensor units (77), which consists of one or more magnetic sensor units (21) facing the railway rail. The magnetic sensor units detect an anomaly (102) on the railway rail when the magnetic sensor unit passes over the anomaly. An anomaly is typically a location where the rail tread is different from the normal surface. The detection device outputs a signal based on the detection results from the group of magnetic sensor units.

[0103] The train (or individual cars) may be equipped with one or more detection devices.

[0104] The multiple detection devices include detection devices installed symmetrically on the left and right sides of the train, and / or detection devices installed at the front and rear of the train. The processing unit receives signals output from each of the multiple detection devices and, based on the detection signal (e.g., at least one of signals X, Y, R, and θ) derived from the signals from the multiple detection devices, determines whether the anomaly is a rail joint or a rail fracture.

[0105] If detection devices are installed symmetrically on the train, the following may be the case. As illustrated in Figure 15, rail joints are located symmetrically on the left and right rails, while rail fractures typically do not occur symmetrically on the left and right rails. Therefore, the processing unit determines that a rail joint is located if the detection signals from both detection devices installed symmetrically on the train (detection signals with the same position (e.g., x-coordinate) along the direction of train travel, or detection timing) indicate a unique location. On the other hand, if the detection signal from one of the detection devices installed symmetrically on the train indicates a unique location, the processing unit determines that a rail fracture is located.

[0106] If detection devices are installed at both the front and rear of the train, the following may be the case. As illustrated in Figure 15, rail joints exist in advance, while rail fractures can occur dynamically during train operation. Therefore, the processing unit may determine that a particular location is a rail joint if the detection signals from both detection devices installed at both the front and rear of the train indicate a particular location. On the other hand, the processing unit may determine that a particular location is a rail fracture if the detection signal from one of the detection devices installed at both the front and rear of the train (typically the rear detection device) indicates a particular location. Note that the detection devices installed at both the front and rear of the train may include a detection device installed in the leading car and a detection device installed in the last car.

[0107] The processing device may output display information for a display object (134) that represents at least one of a rail joint location as a singularity and a rail fracture location as a singularity. The display information may also include information for a display object (136) representing the location of the singularity represented by the display object.

[0108] If a rail fracture is detected, the processing device may identify which rail the fracture is located on.

[0109] If a rail joint is identified by discriminating an anomaly, the processing unit may estimate the train's position based on the known location of the rail joint. For example, if each rail joint is associated with a known location, the processing unit can estimate the train's position to be the location associated with that rail joint when a rail joint is identified.

[0110] As illustrated in Figure 15, rail joints are located at equal intervals. Therefore, if the detected anomalies are at equal intervals, the processing device may determine that all of them are rail joints. On the other hand, if the detected anomalies include anomalies that are not at equal intervals, the processing device may determine that the anomalies other than those at equal intervals are rail fractures. Note that, for example, in this paragraph, only one detection device is necessary (i.e., detection devices do not necessarily have to be installed symmetrically on the left and right or front and rear of the train).

[0111] The detection device may be a device that excites the tread surface of the railway rail with an alternating magnetic field and detects anomalies in the railway rail based on disturbances in the flow of magnetic flux generated in the railway rail. Each of the one or more magnetic sensor units comprises a receiving coil and two elements flanking the receiving coil. oscillationThe device may include coils. The processing device may determine that the detected singularity is a rail joint if the relationship between the distance between the extremes of the detected signal and the distance between the oscillating coils is a predetermined relationship. On the other hand, the processing device may determine that the detected singularity is a rail fracture if the relationship between the distance between the extremes of the detected signal and the distance between the oscillating coils is not a predetermined relationship. The distance between the oscillating coils may be defined based on the diameters of the oscillating coil and the receiving coil.

[0112] Detection devices (for example, detection devices provided symmetrically on the left and right sides, and / or detection devices provided at the front and rear) may be present on two or more of the vehicles. For each of the two or more vehicles, a specific location may be identified. Based on the results of the identification of the specific location for each of the two or more vehicles, the processing device may identify whether the specific location is a joint or a rail fracture. For example, if the results of the identification of the specific location differ among the vehicles, the most frequent identical identification result may be considered the final identification result. [Explanation of Symbols]

[0113] 1, 1a, 1b Rail condition monitoring device 2, 2a, 2b detection devices 3, 3a, 3b processing equipment 4. Evaluation device 5A-1~5A-N, 5B-1~5B-N Oscillator Coils 6-1~6-N Receiving Coil 20 Lower enclosure (first enclosure) 21-1~21-N Magnetic Sensor Section 77 Magnetic sensor group 100 railroad tracks 100a tread surface 102 Unique locations (joint locations and rail fracture locations) 110 vehicles (railway vehicles)

Claims

1. Multiple detection devices are installed on trains running on the left and right railway rails that make up the track, Processing device and Equipped with, The aforementioned train is a formation of one or more cars, For each of the aforementioned plurality of detection devices, The detection device has a group of magnetic sensor units, which are one or more magnetic sensor units facing the railway rail, and is a device that excites the tread surface of the railway rail with an alternating magnetic field and detects anomalies in the railway rail based on disturbances in the flow of magnetic flux generated in the railway rail. Each of the one or more magnetic sensor units detects a specific location on the railway rail when the magnetic sensor unit passes over such location, and includes a receiving coil and two oscillating coils flanking the receiving coil. The detection device outputs a signal based on the detection results from the magnetic sensor group. The plurality of detection devices include detection devices provided symmetrically on the left and right sides of the train, and / or detection devices provided at the front and rear of the train. The processing device receives signals output from each of the plurality of detection devices and, based on the detection signals derived from the signals from the plurality of detection devices, distinguishes whether the anomaly is a rail joint or a rail fracture. The aforementioned processing apparatus is If the relationship between the distance between the extreme values ​​of the detection signal and the distance between the oscillation coils is a predetermined relationship, it is determined that the detected anomaly is a rail joint. If the relationship between the distance between the extreme values ​​of the detection signal and the distance between the oscillation coils is not the predetermined relationship, it is determined that the detected anomaly is a rail fracture location. Rail condition monitoring device.

2. The aforementioned processing apparatus is If the detection signals from both detection devices symmetrically installed on the aforementioned train indicate a specific location, it is determined that the specific location is a rail joint. If the detection signal from one of the detection devices symmetrically installed on the aforementioned train indicates a specific location, it is determined that this location is a rail fracture site. Rail condition monitoring device according to claim 1.

3. The aforementioned processing apparatus is If the detection signals from both detection devices installed at the front and rear of the aforementioned train indicate a specific location, it is determined that the specific location is a rail joint. If the detection signal from one of the detection devices installed at the front and rear of the aforementioned train indicates a specific location, it is determined that this specific location is a rail fracture location. Rail condition monitoring device according to claim 1.

4. The detection devices provided at the front and rear of the aforementioned train include a detection device provided at the leading car and a detection device provided at the rear car. Rail condition monitoring device according to claim 3.

5. The processing device outputs display information for a display object that represents at least one of the following: a rail joint location as a unique location, and a rail fracture location as a unique location. Rail condition monitoring device according to claim 1.

6. The aforementioned display information includes information representing the display object at the location of the singularity represented by the display object. Rail condition monitoring device according to claim 5.

7. When a rail fracture is detected, the processing device identifies which rail the fracture is located on. Rail condition monitoring device according to claim 1.

8. If a rail joint is identified by discriminating an anomaly, the processing device estimates the position of the train based on the known location of the rail joint. Rail condition monitoring device according to claim 1.

9. The aforementioned processing apparatus is If the detected anomalies are at equal intervals, it is determined that all of them are rail joints. If the detected anomalies include anomalies that are not evenly spaced, then the anomalies other than those that are evenly spaced will be determined to be rail fracture locations. Rail condition monitoring device according to claim 1.

10. The system receives signals output from multiple detection devices installed on trains running on the left and right railway rails that make up the track. The aforementioned train is a formation of one or more cars, For each of the aforementioned plurality of detection devices, The detection device has a group of magnetic sensor units, which are one or more magnetic sensor units facing the railway rail, and is a device that excites the tread surface of the railway rail with an alternating magnetic field and detects anomalies in the railway rail based on disturbances in the flow of magnetic flux generated in the railway rail. Each of the one or more magnetic sensor units detects a specific location on the railway rail when the magnetic sensor unit passes over such location, and includes a receiving coil and two oscillating coils flanking the receiving coil. The detection device outputs a signal based on the detection results from the magnetic sensor group. The plurality of detection devices include detection devices provided symmetrically on the left and right sides of the train, and / or detection devices provided at the front and rear of the train. The system receives signals output from each of the aforementioned multiple detection devices, and performs a discrimination step to determine whether the anomaly is a rail joint or a rail fracture based on the detection signals from the multiple detection devices. If the relationship between the distance between the extreme values ​​of the detection signal and the distance between the oscillation coils is a predetermined relationship, the discrimination step determines that the detected anomaly is a rail joint. If the relationship between the distance between the extreme values ​​of the detection signal and the distance between the oscillation coils is not the predetermined relationship, the discrimination step determines that the detected anomaly is a rail fracture location. Rail condition monitoring method.

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