Railroad vehicle derailment detection device

Abstract

To provide a railroad vehicle derailment detection device capable of shortening a time loss until derailment detection.SOLUTION: A railroad vehicle derailment detection device comprises: means for detecting an impact associated with landing by comparing an acceleration detection value of vertical oscillations acquired through an acceleration sensor with a predetermined first threshold; means for calculating effective acceleration values within a predetermined time width; threshold calculation means for calculating a second threshold to detect a derailment on the basis of the effective acceleration value within a predetermined period among the calculated effective acceleration values; and derailment determination means for determining whether a derailment has occurred by comparing the calculated effective acceleration value with the second threshold. The threshold calculation means calculates the effective acceleration value by measuring acceleration due to the oscillations generated during normal travel on rails and stores a value obtained by multiplying the effective acceleration value in a predetermined speed range by a safety factor as the second threshold for derailment detection. The derailment determination means determines the occurrence of a derailment when the effective acceleration value exceeds the second threshold corresponding to a vehicle speed at that time and this state continues for a specified period or longer.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a derailment detection device for railway vehicles, and more particularly to a technique effective for use in a derailment detection device that detects derailment of a railway vehicle running on a track based on acceleration data of vertical vibration acquired from an acceleration sensor.

Background Art

[0002] When a running railway vehicle derails, it is effective to decelerate the vehicle before a serious accident occurs, and for this purpose, it is necessary to detect derailment promptly after it occurs. Conventionally, as inventions related to derailment detection methods and devices for railway vehicles, there are, for example, those described in Patent Documents 1 and 2.

[0003] Among these, the derailment detection method described in Patent Document 1 obtains the vertical displacement amount by double-integrating the vertical acceleration of the part above the bogie spring, and detects derailment when the vertical displacement amount per unit time is negative and its absolute value is equal to or greater than a predetermined value. Further, the derailment detection device described in Patent Document 2 extracts a signal in a specific frequency band from the output signal of the acceleration detection means, repeatedly integrates the signal in the specific frequency band every predetermined time to obtain an integration value corresponding to vehicle vibration, and determines derailment of the vehicle based on the fact that the difference between the integration value and the integration value before a predetermined time exceeds a predetermined value.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Since the derailment detection method described in Patent Document 1 focuses on the vertical sway of the part above the bogie spring to detect derailment, there is a risk of false detection of derailment even when the part above the bogie spring is greatly displaced vertically due to an earthquake or the like without derailment. Therefore, there is a risk that a larger accident may occur than when the brakes are not applied, such as a passenger moving inside the vehicle falling and being injured by applying an emergency brake due to a false determination of derailment.

[0006] On the other hand, the derailment detection device described in Patent Document 2 acquires an integrated value corresponding to vehicle vibration every predetermined time, calculates the difference between the acquired integrated value and the integrated value before the predetermined time, and determines whether the difference exceeds a predetermined value to detect derailment of the vehicle. If the predetermined time is, for example, 1 second, in order to improve the detection accuracy, it is necessary to repeatedly execute the calculation and comparison of the difference from the integrated value of the predetermined time 1 second before, the calculation and comparison of the difference from the integrated value of the predetermined time 2 seconds before, and the calculation and comparison of the difference from the integrated value of the predetermined time 3 seconds before. As a result, a relatively large time loss may occur before derailment is detected.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a derailment detection device for a railway vehicle that can shorten the time loss until derailment is detected. Another object of the present invention is to provide a derailment detection device for a railway vehicle that can detect derailment with high accuracy while avoiding false detection. Still another object of the present invention is to provide a derailment detection device for a railway vehicle that can equip the vehicle with a derailment detection function without causing a significant cost increase.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention In a derailment detection device for a railway vehicle that is mounted on a vehicle traveling on a railway track and equipped with vehicle speed detection means, and performs derailment detection based on data acquired from a plurality of acceleration sensors installed on one bogie frame Impact detection means for detecting an impact associated with the landing of a wheel on a track by comparing an acceleration detection value of vertical vibration acquired from the acceleration sensor with a predetermined first threshold value set in advance. Effective value calculation means for calculating an effective value of acceleration within a predetermined time width based on the acceleration detection value of vertical vibration acquired from the acceleration sensor. Threshold value calculation means for calculating a second threshold value for derailment detection based on the effective value within a first predetermined time set in advance among the effective values of acceleration calculated by the effective value calculation means. Derailment determination means for comparing the effective value of acceleration calculated by the effective value calculation means with the second threshold value calculated by the threshold value calculation means to determine whether derailment has occurred. The threshold value calculation means measures the acceleration due to vibration generated during normal rail travel and calculates its effective value, and calculates a value obtained by multiplying the effective value by a margin coefficient with respect to the effective value within a predetermined speed range as the second threshold value for derailment detection, and stores it in association with the speed data acquired from the vehicle speed detection means. The effective value calculation means stops the calculation process of the effective value after a predetermined time from when the impact detection means detects an impact. The derailment determination means is configured to determine that derailment has occurred when a state where the effective value of acceleration calculated by the effective value calculation means exceeds the second threshold value corresponding to the vehicle speed at that time continues for a second predetermined time or more.

[0009] According to the derailment detection device for a railway vehicle having the above configuration, it is possible to make a derailment detection determination within a short time after derailment occurs. In addition, it is possible to detect vehicle abnormalities such as derailment with high accuracy while avoiding false detection. Furthermore, by performing derailment detection based on the acceleration data collected by an existing bogie monitoring device mounted on the vehicle, it is possible to equip the vehicle with a derailment detection function without causing a significant cost increase.

[0010] Also, preferably, the threshold value calculation means is configured to determine the margin coefficient as a value that can clearly distinguish between the effective value of acceleration during normal travel and the effective value of acceleration during derailment. According to such a configuration, since it is possible to determine derailment detection with a threshold value having a margin with respect to the effective value of the acceleration during normal rail running, even if the value obtained from the acceleration sensor becomes large by running through a location where rail joints are continuous or a switch during normal rail running, it is possible to avoid erroneously determining derailment.

[0011] Furthermore, preferably, the acceleration sensor is an acceleration sensor installed on the bogie frame. The impact detection means is configured to detect an impact associated with the landing of the wheel by comparing the value of the acceleration detected by the acceleration sensor with the first threshold value. According to such a configuration, it is possible to accurately detect the timing when the wheel lands on the track due to derailment from the impact generated when the wheel lands. By detecting the wheel landing timing, it is possible to appropriately set the acquisition time and set a threshold value suitable for derailment detection.

[0012] Furthermore, preferably, a first filter means for performing filter processing for deriving impact acceleration on the data obtained from the acceleration sensor, and a second filter means for performing filter processing for deriving an effective value on the data obtained from the acceleration sensor are provided. The impact detection means detects an impact associated with the landing of the wheel based on the data filtered by the first filter means. The effective value calculation means is configured to calculate an effective value of the acceleration based on the data filtered by the second filter means.

[0013] According to the above configuration, it is possible to remove the noise component included in the data obtained from the acceleration sensor, calculate a highly accurate impact acceleration, detect the wheel landing timing, and calculate a highly accurate effective value of the acceleration to perform accurate derailment detection.

[0014] Furthermore, preferably, the second predetermined time is set based on the time during which the impact (acceleration) previously obtained at a location where rail joints are continuous or at a switch during normal running continues. According to such a configuration, when the vehicle is passing through a rail joint or a switch, it is possible to prevent the derailment determination means from erroneously determining the occurrence of derailment.

Effects of the Invention

[0015] According to the derailment detection device for a railway vehicle according to the present invention, it is possible to make a derailment detection determination within a short time after derailment occurs. In addition, it is possible to detect vehicle abnormalities such as derailment with high accuracy while avoiding false detection. Furthermore, there is an effect that the vehicle can be equipped with a derailment detection function without causing a significant cost increase.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0017] Hereinafter, with reference to the drawings, a derailment detection device for a railway vehicle according to the present invention will be described in detail. FIG. 1 shows the overall configuration of a derailment detection system applied to the derailment detection device for a railway vehicle according to the present invention. Note that FIG. 1 is a schematic configuration diagram of an embodiment when the derailment detection device according to the present invention is applied to an existing vehicle equipped with a bogie monitoring device.

[0018] As shown in Fig. 1, the derailment detection system using the derailment detection device of the railway vehicle of the present embodiment includes a bogie monitoring device 20 that collects data from an acceleration sensor 21 that detects the acceleration of vertical vibration installed on the bogie frame 30, and a derailment detection device 10 that reads the acceleration data from the data collected by the bogie monitoring device 20 and performs derailment detection.

[0019] In addition, the existing bogie monitoring device 20 is configured to collect data from, for example, a pressure sensor provided on an air spring installed on the bogie frame 30, in addition to data from the acceleration sensor. The derailment detection device 10 performs derailment detection using the data of the acceleration sensor 21 among the data collected by the bogie monitoring device 20.

[0020] The above derailment detection device 10 is mounted on a vehicle that travels on the rails of a railway track. When applying to a vehicle not equipped with the bogie monitoring device 20, the acceleration sensor 21 may be provided on the bogie frame 30, and signals from these sensors may be directly input to the derailment detection device 10. In addition, in an existing railway vehicle equipped with the bogie monitoring device 20, an abnormality detection device is provided, and based on the data collected by the bogie monitoring device 20, for example, it is configured to detect abnormalities such as whether there is a crack in the bogie frame 30.

[0021] The derailment detection device 10 includes an arithmetic processing device 11 that determines whether a derailment has occurred based on the vertical acceleration data acquired from the acceleration sensor 21, a storage device 12 that stores set values and the like used for the determination of derailment detection, a communication device 13 that transmits a command signal to the travel control device 22 to decelerate the vehicle by the brake device 24 based on the determination result by the arithmetic processing device 11, and the like.

[0022] The arithmetic processing unit 11 of the derailment detection device 10 can be constituted by a normal microprocessor or microcomputer having a CPU (Central Processing Unit), ROM, RAM, etc., and has a function of performing derailment detection processing through cooperation between the program stored in the ROM and the CPU. Further, the arithmetic processing unit 11 is programmed to perform derailment detection processing according to the derailment detection algorithm described later, which is a feature of the present invention, based on the acceleration data acquired by the acceleration sensor. And when the arithmetic processing unit 11 of the derailment detection device 10 determines that the vehicle has derailed, it transmits a command signal to decelerate the vehicle to the travel control device 22 mounted on the vehicle via the communication device 13. Note that the travel control device 22 has a function of controlling a motor drive device 23 that drives a travel motor in addition to a brake device 24.

[0023] Note that the acceleration sensor 21 installed on the bogie frame 30 may be any sensor that can detect at least the acceleration in the vertical direction (vertical direction). Further, a three-axis acceleration sensor may be used as the acceleration sensor 21, and the acceleration in the vertical direction may be extracted from the three-axis acceleration sensor and input to and stored in the bogie monitoring device 20.

[0024] Next, the derailment detection algorithm for a railway vehicle used in the derailment detection device 10 according to the embodiment of the present invention will be described. Before that, the derailment test and test results that led to the recollection of the derailment detection algorithm of the present invention will be described. The inventors predicted that abnormal bogie vibrations far exceeding the bogie vibrations during normal travel would occur during vehicle derailment, so it was considered that derailment could be detected by monitoring the vibrations of the bogie, and it was thought that it would be good to use a bogie frame acceleration sensor for vibration detection. In addition, since some existing vehicles are provided with a bogie monitoring device equipped with a bogie frame acceleration sensor, it was decided to conduct a test using the bogie frame acceleration sensor of that bogie monitoring device.

[0025] Specifically, the bogie was removed from the actual vehicle, and dead weights (equivalent to empty vehicle and full vehicle) were mounted on the test bogie so that the normal configuration of the actual vehicle and the load on the axle springs were equivalent. Also, the outer springs were removed from the axle springs and only the inner springs were used. Further, a part of the rails on the track was removed, and derailment was simulated by dropping the test bogie placed on the rails from the rails onto the track. The lengths of the left and right rails were made different to change the wheel drop timing of the left and right wheels, and a test was conducted to obtain vibrations when running on the track from the acceleration sensors provided on the bogie frame.

[0026] The test results are shown in FIG. 2. In FIG. 2, P1 is the acceleration due to the landing of the first wheel, and P2 is the acceleration due to the landing of the opposite wheel. From the test results, it was found that considerably large accelerations occur at wheel landing compared to when running on the rails. Also, using the data from the acceleration sensors, the root mean square (RMS) values of the accelerations of the vertical vibrations were calculated every 0.2 seconds before and after wheel landing. As a result, it was found that considerably large RMS values of accelerations occur when running on the track after derailment compared to when running on the rails.

[0027] Note that as described above, the reason why there is a relatively large difference in the magnification of the RMS values of the accelerations before and after derailment is considered to be that vibrations during running are transmitted from the axle box to the bogie frame via the axle box support device. The present invention has been made based on the findings obtained from the test results as described above. Hereinafter, the derailment detection algorithm of the present invention will be described.

[0028] As shown in FIG. 3, the derailment detection algorithm of the present invention first performs parallel filter processing (S1) for deriving impact acceleration and filter processing (S2) for deriving the RMS value on the acceleration data obtained in time series from the acceleration sensors 21 provided on the bogie frame, using preset filter coefficients respectively. Note that since there are differences in the frequency of acceleration during normal running and derailment, the filtering process (S1, S2) is performed to extract vibrations in a frequency band specific to derailment. The filter coefficients may be determined by comparing the respective vibration frequencies obtained from the acceleration sensor in advance during rail running and during a track running test, and finding the frequency band where a difference appears.

[0029] Subsequently, an impact determination process (S3) for determining whether there has been an impact greater than or equal to a predetermined level (detecting P2 in FIG. 2) using the acceleration filtered in the above process S1 and a preset threshold value TH1, and an effective value calculation process (S4) for calculating the root mean square (RMS) of the acceleration data filtered in S2 are executed, for example, every 0.2 seconds. In the impact determination process (S3), the impact may be determined based on whether the "ratio" with the previous acceleration exceeds a preset threshold value. The threshold value TH1 in the above impact determination process (S3) varies depending on the vehicle to which the present invention is applied and the track on which it runs, so it is advisable to determine an appropriate value through experiments in advance.

[0030] On the other hand, during derailment, the speed of the vehicle drops rapidly, so the impact during derailment increases according to the running speed of the train at that time. Therefore, separately from the above process, based on the maximum value of the effective acceleration during track running and the measurement results of the bogie frame vibration transmission characteristics obtained in a bogie derailment test in advance, and further based on the effective acceleration corresponding to the speed obtained during normal rail running, a threshold value TH2 is determined. Then, the determined threshold value together with the duration is stored in the storage device 12 as a speed table.

[0031] Specifically, in the bogie derailment test, only the effective acceleration value when the vehicle is run at a low speed such as several km / h and derailed can be obtained. To expand the threshold (coefficient) setting to the range of the running speed of the actual vehicle, it is conceivable to increase the effective acceleration value obtained at a speed of several km / h in the derailment test in proportion to the speed for setting. However, in the actual running of the vehicle, the effective acceleration value is not proportional to the running speed due to the influence of switches and the like.

[0032] Therefore, the acceleration due to vibrations generated during normal rail travel of the vehicle is measured, and its effective value is calculated. Then, for the effective value of the measured acceleration, a value obtained by multiplying the effective value within the range of, for example, the acceleration performance and deceleration performance of the vehicle by a margin coefficient is determined as the threshold value at each vehicle speed and stored in the storage device 12 as a speed table. Here, the margin coefficient is determined based on the ratio between the effective value of the acceleration during normal rail travel and the effective value of the acceleration obtained from a derailment test at low speed. The dotted line B in FIG. 4 indicates the threshold value determined as described above. Also, in FIG. 4, the effective value of the acceleration measured during normal travel is indicated by the solid line A. From FIG. 4, it can be seen that the set threshold value TH2 of the speed table of the dotted line B has a sufficient margin with respect to the solid line A of the measured maximum value.

[0033] Also, when it is determined in the impact determination process (S3) that an impact has occurred, a timer is started, and a time measurement process (S6) for a preset determination off delay time (for example, 5 seconds) is performed. When the determination off delay time has elapsed, the calculation process (S4) of the effective value of the acceleration data is stopped. Then, when it is determined in the impact determination process (S3) that an impact has occurred, using this as a trigger, a derailment determination process (S7) is executed to determine whether or not derailment has occurred based on whether or not a state where the effective value of the acceleration after the impact occurrence calculated in the effective value calculation process (S4) exceeds the threshold value TH2 determined in the threshold value calculation process (S5) has continued for a preset duration or more. Also, when it is determined that derailment has occurred, the derailment detection device 10 notifies the travel control device 22 of the derailment detection, and the travel control device 22 performs control to operate the brake device 24 to decelerate the vehicle.

[0034] Note that the "duration" used in the process in the derailment determination process (S7) needs to prevent false derailment detection when the vehicle passes through locations where rail joints are continuous or switches during normal travel. Therefore, it is advisable to set it to be as short as possible within the range where false detection does not occur, using the duration for which the impact (acceleration) previously acquired at locations where rail joints are continuous or switches during normal travel continues. The time set in this way is referred to as the minimum duration within the normal limit range.

[0035] Also, it is possible to set a fixed time (e.g., 1 second) for the duration (≒ detection time) across the entire speed range. By doing so, detection can be performed in a short time. However, since the threshold for derailment detection is set using data obtained from derailment tests in the low-speed range and data during normal running, there is a speed range where false detection may occur for normal running data. Therefore, a longer duration may be set for the speed range where false detection may occur.

[0036] As described above, according to the derailment detection device of the above embodiment, it is possible to make a determination of derailment detection within a short time after derailment occurs. Also, it is possible to detect vehicle abnormalities such as derailment with high accuracy while avoiding false detection. Furthermore, by performing derailment detection based on the acceleration data collected by the existing bogie monitoring device mounted on the vehicle, the vehicle can be equipped with the derailment detection function without a significant cost increase.

[0037] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the present invention is not limited to the above embodiments. For example, in the above embodiment, derailment detection is performed based on the detection value of one acceleration sensor installed on the bogie frame. However, derailment detection may be performed based on the detection values of a plurality of acceleration sensors installed on the bogie frame. Also, in that case, the maximum value among the detection values of the plurality of acceleration sensors may be used, or an averaged value may be used. Also, in the above embodiment, derailment detection is performed based on the effective value calculated from the acceleration detected by the acceleration sensor installed on the bogie frame. However, derailment detection may be performed based on the acceleration before calculating the effective value.

Explanation of Reference Numerals

[0038] 10 Derailment detection device 11 Arithmetic processing device (arithmetic means) 12 Storage device (storage means) 13 Communication device 20 Bogie monitoring device 21 Acceleration sensor 22 Travel control device 25 Speed detector (vehicle speed detection means) 30 Car body frame

Claims

1. A derailment detection device for a railway vehicle that is mounted on a vehicle traveling on a railway track and equipped with vehicle speed detection means, and performs derailment detection based on data obtained from a plurality of acceleration sensors installed on one bogie frame, impact detection means for comparing an acceleration detection value of vertical vibration obtained from the acceleration sensor with a preset first threshold value to detect an impact associated with the landing of a wheel on the track; effective value calculation means for calculating an effective value of acceleration within a predetermined time width based on the acceleration detection value of vertical vibration obtained from the acceleration sensor; threshold value calculation means for calculating a second threshold value for derailment detection based on the effective value within a preset first predetermined time among the effective values of acceleration calculated by the effective value calculation means; derailment determination means for comparing the effective value of acceleration calculated by the effective value calculation means with the second threshold value calculated by the threshold value calculation means to determine whether derailment has occurred, comprising: The threshold value calculation means measures the acceleration due to vibration generated during normal rail travel and calculates its effective value, and calculates a value obtained by multiplying the effective value by a margin coefficient with respect to the effective value within a predetermined speed range as the second threshold value for derailment detection, and stores it in association with the speed data obtained from the vehicle speed detection means. The effective value calculation means stops the calculation process of the effective value after a predetermined time from when the impact detection means detects an impact. The derailment determination means determines that derailment has occurred when a state in which the effective value of acceleration calculated by the effective value calculation means exceeds the second threshold value corresponding to the vehicle speed at that time continues for a second predetermined time or more. A derailment detection device for a railway vehicle, characterized by the above.

2. The derailment detection device for a railway vehicle according to claim 1, wherein the threshold value calculation means determines the margin coefficient to a value that can clearly distinguish between the effective value of acceleration during normal travel and the effective value of acceleration during derailment.

3. The acceleration sensor is an acceleration sensor installed on a bogie frame. The derailment detection device for a railway vehicle according to claim 1 or 2, wherein the impact detection means detects an impact associated with wheel landing by comparing the value of the acceleration detected by the acceleration sensor with the first threshold value.

4. first filter means for performing filter processing for deriving impact acceleration on the data acquired from the acceleration sensor; second filter means for performing filter processing for deriving an effective value on the data acquired from the acceleration sensor, and comprising: the impact detection means detects an impact associated with wheel landing based on the data filtered by the first filter means; The derailment detection device for a railway vehicle according to claim 3, wherein the effective value calculation means calculates an effective acceleration value based on the data filtered by the second filter means.

5. The derailment detection device for a railway vehicle according to claim 4, wherein the second predetermined time is set based on the time during which the impact previously acquired at a location where rail joints are continuous or at a switch during normal running continues.

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