The present invention relates generally to rail state monitoring.
JP2014-102197A describes a magnetic induction type rail flaw detector for detecting a surface flaw and a lateral laceration on an inspection rail.
There are rail-to-rail seams in a track. A fracture in a rail can also occur due to a flaw (especially lateral laceration) in the rail or other causes. Where there are rail seams or rail fractures, at least part of a rail surface is separated in a longitudinal direction of the rail.
Although the magnetic induction type rail flaw detector described in JP2014-102197A can detect the surface flaw and the lateral laceration on the inspection rail, the magnetic induction type rail flaw detector cannot discriminate between the rail fracture and the rail seam.
An object of the invention is to discriminate between the rail fracture and the rail seam.
To solve the above problems, a typical rail state monitoring apparatus of the invention includes a plurality of detection devices provided on a train that travels on left and right railroad rails forming a track, and a processing device. The train is composed of one or a plurality of vehicles. For each of the plurality of detection devices, the detection device has a magnetic sensor unit group that is one or more magnetic sensor units facing the railroad rail; the magnetic sensor unit detects a peculiar point when the magnetic sensor unit passes over the peculiar point on the railroad rail; and the detection device outputs a signal based on a result of the detection by the magnetic sensor unit group. The plurality of detection devices include detection devices provided symmetrically on right and left sides of the train and/or detection devices provided on front and rear sides of the train. The processing device receives signals output respectively from the plurality of detection devices, and discriminates whether the peculiar point is a rail seam point or a rail fracture point based on a detection signal based on the signals from the plurality of detection devices.
According to the invention, it is possible to discriminate between the rail fracture(s) and the rail seam(s).
Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.
Several embodiments will be described below with reference to the drawings.
External Configuration of First Embodiment
In
The vehicle 200 travels on the railroad rail 100 (hereinafter, referred to as a rail 100) as an inspection target. That is, a wheel 112 of the vehicle 200 rotates while being in contact with the tread 100a. In this case, the detection device 2 detects a state of the rail 100, and a signal representing a detection result is sent to the processing device 3 via a connection cable 64. Then, processing such as signal collection, signal analysis, and display is executed in the processing device 3, and the state of the rail 100 can be monitored. The power supply 111 may be a stabilized power supply circuit that is provided in the vehicle and driven by an alternating current of 100 V, or may be an uninterruptible power supply device with a built-in battery. Incidentally, an object called a “ground element” may be embedded in a sleeper 500 or the like of the rail 100, and an object called an “onboard element” may be installed in the vehicle 200.
In
Through holes 25a are respectively formed in four corners of the flange 25. Further, the vehicle 200 (see
As described above, although the detection device 2 is fixed at the predetermined position on the vehicle 200, the predetermined position is preferably a position where a center line (not illustrated) in a width direction of the rail 100 and a center line CL (see
As illustrated in
Further, a magnetic sensor unit 21-k (k is any integer from 1 to N) has an oscillation coil 5A-k, an oscillation coil 5B-k, and a reception coil 6-k. Each of these coils is configured by winding a coated copper wire.
The oscillation coil 5A-k, the reception coil 6-k, and the oscillation coil 5B-k are arranged along a laying direction of the rail 100 (see
In
The amplification filter unit 22-k (k is any integer from 1 to N) amplifies, and performs filtering processing on, the induced voltage generated in the reception coil 6-k, and transmits the amplified and filtered result to the processing device 3 via the connection cable 64 (see
The lower housing 20 is made of a non-magnetic material. This is because the lower housing 20 incorporates the oscillation coils 5A-k and 5B-k for generating alternating magnetic fields and the reception coil 6-k for detecting the magnetic flux generated from the railroad rail. In particular, considering that the detection device 2 is installed outdoors and in a traveling vehicle, the lower housing 20 is preferably made of fiber-reinforced resin or the like, which has excellent impact resistance and environmental resistance.
On the other hand, the upper housing 26 incorporating the preamplifier unit 210 is made of metal such as aluminum that functions as an electromagnetic shield. This is for shielding electromagnetic waves generated from the preamplifier unit 210 and preventing electromagnetic waves from entering the preamplifier unit 210 from the outside. Moreover, it is preferable that the upper housing 26 and the flange 25 have an integral structure. That is, it is preferable to form the flange 25 and the upper housing 26 by cutting a metal block. As a result, strength robustness of the flange 25 and the upper housing 26 can be improved, and the number of components of the detection device 2 can be reduced.
The lower housing 20 has an insert nut (not illustrated) and is screwed to the upper housing 26. Further, the lower housing 20 and the upper housing 26 are integrated by bonding with a silicone adhesive having excellent weather resistance, heat resistance, and cold resistance. Further, as the acceleration sensor unit 212 and the angular velocity sensor unit 214 are mounted on the printed circuit board 210a, movements of the detection device 2 when the vehicle 200 is traveling can be detected.
Further, the printed circuit board 210a includes the temperature sensor unit 216 and the temperature of the circuit board can be monitored, so that changes in the operating state due to heat generation of the amplification filter unit 22 can be constantly checked. Also, since the preamplifier unit 210 is hermetically sealed inside the upper housing 26, the temperature detected by the temperature sensor unit 216 is higher than the outside air temperature. Therefore, when information (for example, information (for example, table or machine learning model) in which the temperature detected by the temperature sensor unit 216 is input and the outside air temperature is output) representing a relationship between the outside air temperature and the temperature inside the upper housing 26 is set in the processing device 3 in advance, and the processing device 3 uses the information, the outside air temperature when the vehicle is traveling can be estimated from the temperature detected by the temperature sensor unit 216.
The connection cable 64 connecting the detection device 2 and the processing device 3 includes a power supply line of the preamplifier unit 210, output signal lines (via amplification filter unit group 79) from the respective reception coils 6-1 to 6-N, input signal lines for excitation signals to the respective oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N, and output signal lines of the acceleration sensor unit 212, the angular velocity sensor unit 214, and the temperature sensor unit 216. Therefore, the connection cable 64 is preferably a multi-pair shielded cable with excellent noise resistance, such as a twisted-pair shielded wire. Also, as a measure against crosstalk in the connection cable 64, the connection cable 64 may be split into two cables. That is, one cable is preferably a multi-pair shielded cable that includes a power supply line of the preamplifier unit 210 and an output signal line of each reception coil 6-k from the amplification filter unit group 79. Also, the other cable is preferably another multi-pair shielded cable that includes input signal lines for excitation signals to each oscillation coil 5A-k and each oscillation coil 5B-k, and output signal lines of the acceleration sensor unit 212, the angular velocity sensor unit 214, and the temperature sensor unit 216.
Thus, the connection cable 64 is preferably configured with a total of two connection cables. The connection cable 64 extends under the vehicle 200 and connects with the processing device 3 through an introduction port under a floor of the vehicle. The connection cable 64 is firmly fixed and held by using a metal binding band or the like in a state where there is no slack of the connection cable 64 under the vehicle 200 so as not to interfere with the traveling of the vehicle. The installation of the connection cable 64 from the detection device 2 to the processing device 3 is preferably designed so that a length of the cable can be shortened as much as possible and an installation route avoids positions where electromagnetic noise is likely to occur from the vehicle 200.
Principles of Detection of Peculiar Points Such as Rail Fracture Points or Seam Points
The meanings of the “x direction” and the “y direction” in
The rail state monitoring apparatus 1 in the present embodiment detects the generated leakage magnetic field based on the change in the flow of the magnetic flux generated in the railroad rail 100, which is an inspection target object, near the peculiar point 102. As an analytical model of this leakage magnetic field, the leakage magnetic field generated in a space can be expressed based on a dipole model. Here, as an example, a case is assumed where the peculiar point 102 is a seam point of the rail 100 in the model. In the leakage magnetic field component generated from the y direction of the rail 100, a bipolar magnetic flux change having an extreme value (maximal value and minimal value) in the x direction appears with a central position of the seam point as an inflection point when the vehicle 200 is traveling.
Discrimination Between Seam Point and Rail Fracture Point
In the example described above, although the case where the peculiar point 102 is the “seam point” of the rail 100 is described, even when the peculiar point 102 is the “rail fracture point” of the rail 100, the rail fracture point can be similarly detected. The principles will be described below. At the rail fracture point of the rail 100, the rails are separated from each other due to metal fatigue that occurred on the rail 100 as the vehicle travels. Therefore, when the detection device 2 passes over the rail fracture point, the flow of the magnetic fluxes OA and OB (see
The seam point(s) and the rail fracture point(s) are of similar shapes where the rails are separated from each other.
Therefore, in the present embodiment, the processing device 3 discriminates whether the peculiar point 102 is a seam point or a rail fracture point based on the magnetic flux disturbance detected by the detection device 2. For this discrimination, an installation configuration is used in which the left and right rails 100 laid in a track are at similar positions (left-right symmetrical positions). That is, since the processing device 3 can monitor the state of the left and right rails 100, the processing device 3 determines that there is a rail seam when a bipolar magnetic flux change occurs in detection signals from the left and right rails 100 at the same time (or the position of the same traveling point). On the other hand, when a bipolar magnetic flux change occurs in the detection signal from one of the left and right rails 100, the processing device 3 determines that there is a rail fracture (see
In discriminating between the seam points and the rail fracture points, the rails 100 are laid regularly in the track, and thus seams are present at certain intervals (see
When the measurement time in the time-series data (data representing the time-series of the detection signal strength) of the detection signal obtained by the rail state monitoring apparatus 1 is converted to a movement distance of the vehicle 200, the distance between the extreme values of the bipolar magnetic flux change generated from the seam point is a numerical value similar to the distance between the centers of the oscillation coils 5A-k and 5B-k illustrated in
An amount of clearance, which is a separation interval between rails at the seam point of the rails 100 in the track may be adjusted to change its size according to the season, taking into account the expansion and contraction of the rails due to a temperature, but basically the amounts of clearance are the same at respective seam points. On the other hand, rail fracture points are not artificially separated in rails like the seam points, but are naturally occurring due to metal fatigue, so the separation end surfaces of the rails are not uniform. As a result, the states of the rail fracture points are not the same for each existing point. In other words, with regard to rail fracture, there are cases where the separation between rails is not evenly uniform, such as at the seam points, such as where the rails are separated obliquely, or where the separation is partial.
The signals detected by the magnetic sensor units 21-1 to 21-N show similar responses at the seam points, regardless of the located positions of the magnetic sensors. For example, respective magnetic sensor units 21 have similar signal strengths (peak-to-peak values) between extreme values and distances between extreme values in a detection signal with bipolar magnetic flux changes. On the other hand, at the rail fracture points, due to the uneven separation of the rails, the respective magnetic sensor units 21 do not have similar signal strengths (peak-to-peak values) between extreme values and the distances between extreme values, and variations occur. That is, by monitoring the deviation of the detection signal obtained by each magnetic sensor unit 21, it is possible to discriminate between the seam point and the rail fracture point.
Considering the risk of a rail fracture that occurs when the vehicle travels, rail state monitoring apparatuses 1 are installed at the front and rear ends of the vehicle 200. As illustrated in
Circuit Configuration of First Embodiment
As described above, the rail state monitoring apparatus 1 has the detection device 2, the processing device 3, and the power supply 111. The detection device 2 has the magnetic sensor units 21-1 to 21-N and the preamplifier unit 210, and the magnetic sensor unit 21-k has the oscillation coils 5A-k and 5B-k and the reception coil 6-k. The preamplifier unit 210 has the amplification filter units 22-1 to 22-N, the acceleration sensor unit 212, the angular velocity sensor unit 214, and the temperature sensor unit 216, and the amplification filter unit 22-k is connected to the magnetic sensor unit 21-k.
In addition, the processing device 3 includes resonance filter units 60-1 to 60-N, amplifier units 31-1 to 31-N, a digital-analog conversion unit 32 of N systems, an oscillation unit 33, detection units 34-1 to 34-N, an analog-digital conversion unit a memory unit 36, and an evaluation device 4 (in the present embodiment, N is an integer equal to two or more, but may be one). The detection units 34-1 to 34-N may be collectively referred to as a “detection unit group”, and the resonance filter units 60-1 to 60-N may be collectively referred to as “resonance filter unit”. The oscillation unit 33 outputs a sinusoidal digital oscillation signal with a predetermined oscillation frequency f. Considering the impedance of the oscillation coils 5A-1 to 5A-N and 5B-1 to the oscillation frequency f is selected to a value that can output a sufficient excitation magnetic field and ensure sufficient sensitivity of the reception coil 6. Also, when selecting the oscillation frequency f, it is preferable to fully consider effects on equipment of the vehicle and railroad tracks. In particular, a selected frequency range is preferably selected from a range of 10 kHz to 100 kHz so as not to affect operations of a driving safety device that supports safe operation of the vehicles and operations of a track circuit that energizes a signal on the railroad rails for signal control.
In
In
Referring back to
By the way, in the present embodiment, the vehicle 200 is also equipped with an inspection device 300 other than the rail state monitoring apparatus 1. The inspection device 300 then supplies the rail state monitoring apparatus 1 with a position signal SD and a distance pulse signal SP. These signals will be described in detail.
A railway system is generally provided with a position detection system. In this system, an object called a “ground element” is buried in a sleeper or the like of the rail 100, and an object called an “onboard element” is installed in the vehicle 200. Then, when the onboard element passes over the ground element, the onboard element detects the ground element. Since an installation position of the ground element is known, when the onboard element detects the ground element, an absolute position of the vehicle 200 at that time becomes clear. The position signal SD described above is a signal for notifying the rail state monitoring apparatus 1 of the position information and the like from the inspection device 300.
However, the ground elements of the position detection system are often installed at intervals of several kilometers, for example. Therefore, it is not possible to acquire the position information of the vehicle 200 in a section between the ground elements only with the position detection system. Therefore, by associating the position information of the seam point detected by the rail state monitoring apparatus 1 with the position information of the ground element, the processing device 3 calculates the absolute position information of the vehicle 200 from the detection data acquired when passing the seam point. In this case, the position of the seam point first detected by the rail state monitoring apparatus 1 when the vehicle starts traveling is used as a starting point to estimate a subsequent operation position(s) of the vehicle. The inspection device 300 also detects a rotation angle of a wheel 112 (see
Next, the evaluation device 4 will be described. The evaluation device 4 is equipped with hardware as a general computer such as a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), a hard disk drive (HDD), and the like, and the HDD stores an operating system (OS), application programs, various data, and the like. The OS and application programs are developed in the RAM and executed by the CPU.
The evaluation device 4 includes 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. The evaluation device 4 executes an inspection processing program that specifies the peculiar points 102 of the rail 100 (see
The control unit 42 is, for example, a CPU (an example of a processor), and controls reading of inspection data from the memory unit 36, arithmetic processing, and the like. The data processing unit 43 performs inspection processing based on the inspection data (details will be described below). The display unit 46 is a liquid crystal display (LCD), a cathode ray tube (CRT) display, or the like for displaying inspection results and the like. The output processing unit 44 causes the display unit 46 to display the results of rail state monitoring and the like. In this case, the output processing unit 44 performs processing for displaying in a visually easy-to-understand display format by appropriately using a graph or table format. The operation input unit 45 is information input means such as a keyboard and a mouse. The storage unit 47 stores data such as the inspection results processed by the data processing unit 43. The data stored in the memory unit 36 are also transferred to the storage unit 47. The data processing unit 43 and the output processing unit 44 are implemented by loading programs and data stored in the storage unit 47 into the control unit 42 and executing arithmetic processing.
Also, the phase comparator 74 extracts a component synchronized with the reference signal SR2 in the received signal SS. The extracted signal is filtered by an LPF 78, and the LPF 78 outputs the result as a sine signal Y. A calculator 84 calculates √/(X2+Y2) and outputs the result as an amplitude signal R. Further, a calculator 82 calculates an arctangent of (Y/X), that is, arctan (Y/X), and outputs the result as a phase difference signal θ.
The detection unit 34-k then supplies the above-described respective signals X, Y, R, and θ to the memory unit 36 via the analog-digital conversion unit 35 (see
Here, the reason why the detection unit 34-k detects the sine signal Y in addition to the cosine signal X will be explained. First, when the cosine signal X is important, setting the phase of the reference signal so that the amplitude of the cosine signal X is maximized can be considered. Then, it can be said that this set phase is the optimum phase for detecting the cosine signal X. However, the received signal SS is independent for each of the magnetic sensor units 21-1 to 21-N, and the magnetic sensor units 21-1 to 21-N have respectively different influences of their located positions and manufacturing errors. In addition, the optimum phase also changes due to secular change and temperature change. Therefore, it is troublesome to set the optimum phase of the reference signal for each of the detection units 34-1 to 34-N.
The sine signal Y is a signal component phase-shifted by 90° with respect to the excitation magnetic field that excites the rail. As in the present embodiment, when the sine signal Y is detected together with cosine signal X, the amplitude signal R can be calculated in the calculator 84 (or the evaluation device 4). Since the value of the amplitude signal R is in principle constant even when the phase difference signal θ changes, the process of optimizing the phase of the reference signal can be omitted.
In
Operations of First Embodiment
This process is executed at each predetermined control cycle. In
After step S2 is completed, the evaluation device 4 determines in step S4 whether the predetermined inspection data is out of a predetermined reference range, that is, a range that makes it possible to estimate the relevant peculiar point as a “seam point”. Here, the “predetermined inspection data” is, for example, the amplitude signal R illustrated in
When “No” is determined here, the process proceeds to step S18. The contents of the process will be described below. On the other hand, when it is determined as “Yes” in step S4, the process proceeds to step S10. In step S10, seams and fractures are discriminated based on the signals X, Y, R, and θ illustrated in
When the processes of steps S2 to S16 described above are completed, the process proceeds to step S18 to generate a rail state monitoring result. Here, the “rail state monitoring result” may include the correspondence between the peculiar points (seam points and rail fracture points) and the distance data SK when step S10 is performed (when step S10 is not performed, the “rail state monitoring result” may include a result of no peculiar points). Next, when the process proceeds to step S20, the data processing unit 43 outputs the rail state monitoring result to the display unit 46 and the like, and the process of this routine ends.
The display image 120 includes a railroad rail image 140 and a plurality of alert display objects 130. The railroad rail image 140 schematically displays the rail(s) 100. Also, the alert display objects 130 are displayed at points corresponding to a seam(s) and a rail fracture(s). The alert display object 130 includes a character string “alert”, a structure type display object 134, and a position display object 136.
Here, the structure type display object 134 is a character string representing the type of “seam” or “rail fracture”. Also, the position display object 136 is a numeric number representing the distance from a predetermined reference position to the structure. In this way, by displaying the rail state monitoring result on a graphical user interface (GUI) screen, the user can visually and clearly recognize where on the rails 100 there are seams and rail fractures.
In the example illustrated in
Also, when the detection information represents a “seam”, significant changes appear in each of the signals X, Y, R, and θ illustrated in
In this way, the tagged rail state monitoring results are useful for checking abnormalities in the track due to rail fractures and the amount of clearance. For example, locations where abnormalities are extracted in change in the time-series data of the signals X, Y, R, and θ between the tagged peculiar points can be specified as locations where rail fractures are estimated to occur, and thus the user can check the details on site. Further, since the evaluation device 4 can specify the seam position of the rail, it is possible to grasp in advance the correlation between the amount of change in the time-series data of a display target signal obtained at the seam and the amount of clearance. As a result, it becomes possible to extract the clearance amount of all seams in a travel section when the vehicle is traveling. Here, the clearance amount is affected by the outside air temperature, and the optimum state differs depending on the cold and warm seasons (summer and winter). Therefore, by correcting the temperature information obtained by the temperature sensor unit 216 included in the detection device 2 to the outside air temperature when the vehicle is traveling, the temperature information can be used for managing the clearance amount by the rail state monitoring apparatus 1. In addition, since this rail state monitoring apparatus can be used while the vehicle is traveling, by calculating the difference in the acquired data for each traveling day (inspection day), it can contribute to efficient rail maintenance and management, such as grasping the rail state (occurrence of rail fracture, change in clearance amount, and the like) in the travel section, and grasping the maintenance time and maintenance position of the rail.
As described above, according to the rail state monitoring apparatus 1 of the present embodiment, the detection device 2 has the lower housing 20 and the upper housing 26. The lower housing accommodates the magnetic sensor units 21-1 to 21-N and is made of a non-magnetic material. The upper housing 26 accommodates the preamplifier unit 210 and is fixed to the upper surface of the first housing 20. The connector 28 to be connected to the connection cable 64 is attached to one side face of the upper housing 26. The upper housing 26 is made of metal. Thereby, the state of the rail 100 can be accurately detected.
Further, the detection device 2 excites the tread 100a of the rail 100 with an alternating magnetic field and detects the peculiar point 102 on the tread 100a of the rail 100 based on the turbulence of the magnetic flux flow generated in the rail 100. As a result, the state of the railroad rail can be detected more accurately based on the turbulence of the magnetic flux flow generated in the rail 100.
The rail state monitoring apparatus 1 further includes the oscillation coil 5A-k that generates an alternating magnetic field to excite the rail 100, and the resonance filter unit 60-k connected to the oscillation coil 5A-k. The resonance filter unit 60-k and the oscillation coil 5A-k have a resonance frequency corresponding to the frequency of the alternating magnetic field. This makes it possible to increase the intensity of the alternating magnetic field and to detect the state of the railroad rail more accurately.
The rail state monitoring apparatus 1 further includes the output processing unit 44. The output processing unit 44 expresses the type and existing position of the detected peculiar point 102 as an image and displays the image on the display unit 46. This allows the user to visually recognize the state of the rail 100.
Also, the evaluation device 4 can manage each rail 100 using identification information (identification information of the type of the peculiar point 102) associated with the peculiar point 102 based on the discrimination result of the peculiar point 102.
Further, when it is determined that the detected peculiar point 102 is a seam of the rail 100, the evaluation device 4 calculates the amount of seam clearance based on the turbulence of the magnetic flux flow. This allows the rail state monitoring apparatus 1 to properly manage the amount of seam clearance.
Further, the evaluation device 4 monitors the rail 100 for state changes by accumulating inspection data including at least the types (seam and rail fractures) of peculiar points 102, the number of peculiar points 102, the existing positions of the peculiar points 102, information representing the occurrence of a rail fracture(s), and the amount of seam clearance, for each inspection day, and obtaining the difference in inspection data on different inspection days. As a result, changes in the state of the rail 100 can be accurately monitored based on differences in inspection data on different inspection days.
In addition, the rail state monitoring apparatus 1 of the present embodiment is provided with the detection unit group having a plurality of detection units 34-1 to 34-N for detecting the first detection signal X corresponding to a first phase (0°) of the output signal and the second detection signal Y corresponding to a second phase (90°) of the output signal for the output signal output from each of the reception coils. Thus, it is possible to accurately detect the peculiar points of the rails 100.
The plurality of detection units 34-1 to 34-N output the first detection signal X and the second detection signal Y, or the result R and/or θ obtained by performing arithmetic processing on the first detection signal X and the second detection signal Y. The processing device 3 determines the presence and type of peculiar points from time-series data of signals X, Y, R, and/or θ corresponding to a plurality of magnetic sensor units 21-1 to 21-N. The processing device 3 detects the position of the peculiar point based on the position signal SD and the distance pulse signal SP from the inspection device 300 provided in the vehicle 200 and displays the result on the display unit 46.
Here, by displaying the existing points and existing positions of peculiar points on the rail 100 on the GUI screen, the user can more accurately recognize the peculiar points that exist on the railroad rail. The position signal SD is obtained by the reaction of a sensor (onboard element) mounted on the vehicle and a sensor (ground element) installed near the laid rail during traveling. Since it is difficult to install ground elements so that the positions of all peculiar points existing on the rail 100 can be specified, the positional information of the peculiar points obtained by the position signal SD is limited. In addition, the peculiar point detection accuracy may be affected by the failure of the ground element due to outdoor installation, the response at the position where the onboard element is separated from the ground element, and the response to the ground element in an opposite vehicle section. According to the rail state monitoring apparatus 1 of the present embodiment, using the detection device 2 mounted on a lower side of the vehicle, the peculiar point existing on the tread 100a of the rail 100 can be detected, and thus the detection position accuracy can be maintained.
Next, a second embodiment of the invention will be described. In the following description, parts corresponding to those in
Before describing the configuration of the present embodiment, the first embodiment described above will be reviewed again. As illustrated in
However, when there is a difference in the shape (inner diameter, outer diameter, coil length, or the like) of the oscillation coils 5A-k and 5B-k, the magnetic fluxes OA and OB generated by them will not be canceled in the reception coil 6-k, and thus a noise signal having the same frequency as the oscillation signal is continuously output from the reception coil 6-k. By sufficiently improving the processing accuracy of the oscillation coils 5A-k and 5B-k, this noise signal can be expected to be reduced to a level that does not pose a practical problem, but it is preferable that the noise signal can be reduced even when the processing accuracy is not high. Therefore, in the present embodiment, the noise signal is electrically canceled so that the machining accuracy required for the oscillation coils 5A-k and 5B-k can be lowered.
An external configuration of the rail state monitoring apparatus 1a of the present embodiment is similar to that of the first embodiment (see
The processing device 3a is provided with correction signal generation units 50-1 to 50-N and subtraction units 52-1 to 52-N corresponding to the amplification filter units 22-1 to 22-N. The correction signal generation units 50-1 to 50-N are collectively called a correction signal generation unit group, and the subtraction units 52-1 to 52-N are collectively called a subtraction unit group. As described above, the induced voltage output from the magnetic sensor unit 21-k is superimposed with the noise signal of the oscillation frequency f, and this noise signal is amplified in the amplification filter unit 22-k. In order to cancel this noise signal, the correction signal generation unit 50-k attempts to generate a correction signal having amplitude and phase substantially equal to those of the noise signal. That is, the amplitude and phase are preset in the correction signal generation unit 50-k according to the characteristics of the magnetic sensor unit 21-k.
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, signals with noise signals canceled are supplied to the detection units 34-1 to 34-N. The configuration of the processing device 3a other than the above is similar to that of the processing device 3 of the first embodiment (see
According to the present embodiment, even when the machining accuracy of the oscillation coils 5A-k and 5B-k is low, the noise signal can be electrically canceled and the peculiar points of the rails 100 can be detected with high accuracy.
Next, a third embodiment of the invention will be described. In the following description, parts corresponding to those in
The processing device 3b of the present embodiment includes a signal adjustment unit 70, a digital-analog conversion unit 32a, amplifier units 31A-1 to 31A-N and 31B-1 to 31B-N, and resonance filter units 60A-1 to 60A-N and 60B-1 to 60B-N. In addition, although in the first and second embodiments described above, the oscillation coils 5A-k and 5B-k are connected in series (or in parallel), in the present 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 the 2N-system digital oscillation signals. That is, the signal adjustment unit 70 adjusts the amplitude and phase of the digital oscillation signal output from the oscillation unit 33 corresponding to each of the total 2N oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N.
In addition, the digital-analog conversion unit 32a converts each of the adjusted 2N-system digital oscillation signals into an analog signal. The 2N amplifier units 31A-1 to 31A-N and 31B-1 to 31B-N amplify 2N-system analog signals, respectively. In addition, the 2N resonance filter units 60A-1 to 60A-N and 60B-1 to 60B-N suppress the inductance components of each of the 2N oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N to reduce the impedance, and increase the intensity of the alternating magnetic fields from the oscillation coils. The signal adjustment unit 70 described above adjusts the output balance of the oscillation coils to 5A-N and 5B-1 to 5B-N so that the output voltage of the reception coils 6-1 to 6-N when there is no peculiar point 102 (see
According to the present embodiment, the alternating magnetic fields from the oscillation coils 5A-1 to 5A-N and 5B-1 to 5B-N entering the reception coils 6-1 to 6-N, can be canceled, and thus the balance-adjusted outputs of the magnetic sensor units 21-1 to 21-N can be supplied to the detection units 34-1 to 34-N. As a result, the system gain in the amplification filter units 22-1 to 22-N and the detection units 34-1 to 34-N can be increased, and detection capability in the reception coils 6-1 to 6-N can be improved.
The invention is not limited to the embodiments described above, and various modifications are possible. The above-described embodiments are illustrated for easy understanding of the invention, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to delete part of the configuration of each embodiment, or to add and/or replace other configurations. Also, the control lines and information lines illustrated in the drawings are those considered to be necessary for explanation, and do not necessarily show all the control lines and information lines necessary on the product. In practice, it may be considered that almost all configurations are interconnected. Possible modifications to the above-described embodiments are, for example, the following.
(1) Since the hardware of the evaluation device 4 in each of the above-described embodiments can be implemented by a general computer, a program for executing the processing according to the flowchart illustrated in
(2) In the above-described embodiment, the functions illustrated in
(3) In each of the above-described embodiments, vehicles on which the rail state monitoring apparatus 1 is mounted may be railway vehicles in general, including commercial vehicles (for example, existing railroad line vehicles or Shinkansen vehicles), which are electric vehicles, and inspection vehicles which are diesel locomotive vehicles.
(4) The processing device 3 may detect the position(s) of the peculiar point(s) 102 by using a GNSS position signal obtained by a global navigation satellite system (GNSS) system provided in the vehicles 200 instead of or in addition to the position signal SD and the distance pulse signal SP.
The above description can be summarized as follows, for example. The following summary may include descriptions of supplements and modifications of the above description. In the following description, a width direction of the track is a “right-left” direction, and a longitudinal direction of the track is a “front-back” direction.
The rail state monitoring apparatus (1, 1a, and 1b) includes the detection devices (2) and the processing device (3, 3a, and 3b) provided in a train traveling on the left and right railroad rails (100) forming a track. A train is composed of one or a plurality of vehicles (200).
The detection device includes the magnetic sensor unit group (77) of one or more magnetic sensor units (21) facing the railroad rail. The magnetic sensor unit detects the peculiar point when the magnetic sensor unit passes over the peculiar point (102) on the railroad rail. The peculiar point is typically where the tread of the rail differs from normal. The detection device outputs a signal based on the results of the detection by the magnetic sensor unit group.
A train (or each vehicle) may have one or a plurality of detection devices.
The plurality of detection devices include detection devices provided symmetrically on the right and left sides of the train and/or detection devices provided on the front and back of the train. The processing device receives signals respectively output from the plurality of detection devices, and discriminates whether the peculiar point is a rail seam point or a rail fracture point, based on the detection signal(s) (for example, at least one of the signals X, Y, R, and θ) based on the signals from the plurality of detection devices.
When the detection devices are provided symmetrically on the right and left sides of the train, for example, the following may be applied. As exemplified in
When the detection devices are provided on the front and rear sides of the train, for example, the following may be applied. As exemplified in
The processing device may output display information of the display object (134) representing at least one of the rail seam point as a peculiar point and the rail fracture point as a peculiar point. The display information may include information on the display object (136) of the position of the peculiar point represented by the display object.
When a rail fracture point is determined, the processing device may specify on which rail the rail fracture point is located.
When the rail fracture point is determined by peculiar point discrimination, the processing device may estimate the position of the train based on the known position of the rail fracture point. For example, with each rail seam point associated with a known position, the processing device can estimate the position associated with the rail seam point to be the position of the train when the rail seam point is determined.
As illustrated in
The detection device may be a device that excites the tread of the railroad rail with an alternating magnetic field and detects the peculiar point(s) of the railroad rail based on the turbulence of the magnetic flux flow generated on the railroad rail. Each of one or more magnetic sensor units may include a reception coil and two oscillation coils that pinch the reception coil. The processing device may determine that the detected peculiar point is a rail seam point when the relationship between the distance between the extreme values of the detection signal and the distance between the oscillation coils is a predetermined relationship. On the other hand, the processing device may determine that the detected peculiar point is the rail fracture point when the relationship between the distance between the extreme values of the detection signal and the distance between the oscillation coils is not a predetermined relationship. The distance between the oscillation coils may be defined based on the diameter of the oscillation coil and reception coil.
The detection devices (for example, the detection devices which are provided symmetrically on the right and left sides and/or the detection devices provided on the front and rear sides) may be present in each of two or more vehicles of a plurality of vehicles. For each of the two or more vehicles, peculiar points may be discriminated. The processing device may discriminate whether the peculiar point is a seam point or a rail fracture point, based on the result of the peculiar point discrimination for each of the two or more vehicles. For example, when the results of the peculiar point discrimination are different for different vehicles, the most common discrimination result may be taken as the final discrimination result.
Number | Date | Country | Kind |
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2022-095175 | Jun 2022 | JP | national |