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: 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 oscillations acquired through an acceleration sensor with a predetermined first threshold; effective value calculation means for calculating effective acceleration values within a predetermined time width; means for determining the effective acceleration value before impact detection among the calculated effective acceleration values; means for determining the effective acceleration value after impact detection among the calculated effective acceleration values; effective value ratio calculation means for calculating the ratio between the effective acceleration values before and after the impact detection; and derailment determination means for determining whether a derailment has occurred on the basis of the calculated effective acceleration value ratio. The derailment determination means determines the occurrence of the derailment when the ratio of the effective acceleration values calculated by the effective value ratio calculation means exceeds a predetermined second threshold 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 major accident occurs, and for this purpose, it is necessary to detect derailment promptly after it occurs. Conventionally, as inventions related to railway vehicle derailment detection methods and derailment detection devices, 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 integrated value corresponding to vehicle vibration, and determines derailment of the vehicle based on the fact that the difference between the integrated value and the integrated 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 occurring. Therefore, there is a risk of a larger accident occurring as a result, such as a passenger falling and getting injured while moving inside the vehicle due to a false determination of derailment and sudden braking, compared to the case where no braking is applied.

[0006] On the other hand, the derailment detection device described in Patent Document 2 acquires an integral value corresponding to vehicle vibration at regular intervals, calculates the difference between the acquired integral value and the integral value before a 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 with the integral value of the predetermined time 1 second before, the calculation and comparison of the difference with the integral value of the predetermined time 2 seconds before, and the calculation and comparison of the difference with the integral 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 running on a railway track and performs derailment detection based on data acquired from a plurality of acceleration sensors installed on one bogie frame, Shock detection means for comparing the acceleration detection value of the vertical vibration acquired from the acceleration sensor with a predetermined first threshold value to detect an impact associated with the landing of the wheel on the track, Effective value calculation means for calculating an effective acceleration value within a predetermined time width based on the acceleration detection value of the vertical vibration acquired from the acceleration sensor, First determination means for determining an effective acceleration value before the shock detection by the shock detection means among the effective acceleration values calculated by the effective value calculation means, Second determination means for determining an effective acceleration value after the shock detection by the shock detection means among the effective acceleration values calculated by the effective value calculation means, Effective value ratio calculation means for calculating a ratio between the effective acceleration value before the shock detection determined by the first determination means and the effective acceleration value after the shock detection determined by the second determination means, Derailment determination means for determining whether derailment has occurred based on the ratio of the effective acceleration values calculated by the effective value ratio calculation means, and is provided with, The effective value ratio calculation means stops the calculation process of the effective value ratio after a first predetermined time from when the shock detection means detects a shock, The derailment determination means is configured to determine that derailment has occurred when a state in which the ratio of the effective acceleration values calculated by the effective value ratio calculation means exceeds a predetermined second threshold value continues for a second predetermined time or more.

[0009] According to the derailment detection device of the railway vehicle having the above configuration, it is possible to make a derailment detection determination 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, it is possible to equip the vehicle with a derailment detection function without causing a significant cost increase.

[0010] Also, preferably, the first determination means is configured to determine, as the acceleration effective value before impact detection, the maximum value within a predetermined acquisition time that is a predetermined setting time before the impact detection by the impact detection means among the effective values calculated by the effective value calculation means. According to such a configuration, by appropriately setting the second threshold value, it is possible to calculate a derailment detection threshold value that can clearly distinguish between the acceleration effective value during normal running and the acceleration effective value at the time of derailment, and execute derailment detection.

[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, and by detecting the wheel landing timing, the predetermined acquisition time can be appropriately set, and a threshold value suitable for derailment detection can be set.

[0012] Furthermore, preferably, a first filter means for performing filter processing for deriving impact acceleration on the data acquired from the acceleration sensor, and a second filter means for performing filter processing for deriving an effective value on the data acquired 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 the acceleration effective value 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 acquired from the acceleration sensor, calculate a highly accurate impact acceleration, detect the wheel landing timing, and calculate a highly accurate acceleration effective value to perform accurate derailment detection.

[0014] Furthermore, preferably, the second predetermined time is set based on the time during which the impact (acceleration) previously acquired 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. Further, it is possible to detect vehicle abnormalities such as derailment with high accuracy while avoiding false detection. Furthermore, there is an effect that the derailment detection function can be equipped on the vehicle without causing a significant cost increase.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Modes 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 for railway vehicles 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 a bogie frame 30, and a derailment detection device 10 that reads 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 not only from the acceleration sensor but also, for example, from a pressure sensor provided in an air spring installed on the bogie frame 30. 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 a railway track. When applied 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 setting values and the like used for the determination of derailment detection, a communication device 13 that transmits a command signal to a travel control device 22 to decelerate the vehicle by a 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 configured by a normal microprocessor or microcomputer having a CPU (Central Processing Unit), ROM, RAM, etc., and has a function of performing derailment detection processing in cooperation with 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. When the arithmetic processing unit 11 of the derailment detection device 10 determines that the vehicle has derailed, it transmits a command signal to the travel control device 22 mounted on the vehicle via the communication device 13 to decelerate the vehicle. 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 running would occur when the vehicle derailed, 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 static load and the load on the axle springs were equivalent to those of the actual vehicle. 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 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 during 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, in 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 between normal running and derailment, the filter processing (S1, S2) is performed to extract vibrations in a frequency band specific to derailment. The filter coefficient is preferably 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 occurs.

[0029] Subsequently, an impact determination process (S3) for determining whether there has been an impact greater than or equal to a predetermined value using the acceleration filtered in the above process S1 and a preset threshold value TH1 (detecting P2 in FIG. 2), 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. Since 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, it is advisable to conduct experiments in advance to determine an appropriate value. Also, when it is determined in the impact determination process (S3) that an impact has occurred, in the effective value calculation process (S4), the maximum value within a predetermined acquisition time T2 (for example, 3 seconds) before a predetermined impact pre-set time T1 (for example, 5 seconds) among the calculated effective values is determined as the pre-impact acceleration effective value.

[0030] On the other hand, when it is determined in the impact determination process (S3) that an impact has occurred, a timer is started, and a timing process (S5) for a preset determination off-delay time T3 (for example, 5 seconds) is performed, and the effective value ratio calculation process (S6) of the acceleration data is stopped when the determination off-delay time T3 has elapsed. Here, the effective value ratio calculated in the effective value ratio calculation process (S6) means a value corresponding to B / A when the maximum value of the effective value of the acceleration before the impact is A and the effective value of the acceleration after the impact is B. Then, when it is determined in the impact determination process (S3) that an impact has occurred, a derailment determination process (S7) is executed to determine whether derailment has occurred based on whether the state where B / A calculated in the above effective value ratio calculation process (S6) exceeds a preset predetermined threshold value TH2 has continued for a preset continuous time T4 or more, using this as a trigger.

[0031] Specifically, before derailment, since the vehicle is running on the rail, the amplitude of the vertical acceleration waveform is small. After derailment, since the vehicle is running on the track, the amplitude of the vertical acceleration waveform becomes larger than that during rail running. Therefore, in the above derailment determination process (S7), as shown in FIG. 4, the ratio B / A of the effective acceleration value A during the period Ta before derailment and the effective acceleration value B during the period Tb after derailment is calculated, and when the state where B / A exceeds a preset threshold TH2 continues for a preset time T4 or more, it is determined that derailment has occurred. Further, when it is determined that derailment has occurred, the derailment detection device 10 notifies the running control device 22 of the derailment detection, and the running control device 22 controls to operate the brake device 24 to decelerate the vehicle.

[0032] Note that the bogies differ in structure, dimensions, and weight depending on the vehicle type, and accordingly, the impact value and the effective acceleration value also differ. Therefore, the threshold TH2 in the above derailment determination process (S7) should be set to a magnification such that a clear difference can occur between normal running and derailment. It is advisable to determine it by conducting bogie derailment tests, measuring bogie frame vibration transmission characteristics, etc. for each vehicle type.

[0033] Also, the "continuous time T4" used in the process in the above 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 running. Therefore, it is advisable to set it to the shortest possible time within the range where false detection does not occur, using the time during which the impact (acceleration) previously obtained at locations where rail joints are continuous or switches during normal running continues. The time set in this way is referred to as the minimum continuous time within the normal limit range.

[0034] 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. 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 the 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.

[0035] 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 embodiments, 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. In that case, the maximum value among the detection values of the plurality of acceleration sensors may be used, or the value obtained by averaging may be used.

[0036] In the above embodiments, 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 Signs

[0037] 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 30 Bogie frame

Claims

1. A derailment detection device for a railway vehicle that is mounted on a vehicle running on a railway track and performs derailment detection based on data obtained from a plurality of acceleration sensors installed on one bogie frame, Impact detection means for comparing the acceleration detection value of the vertical vibration obtained from the acceleration sensor with a predetermined first threshold value set in advance to detect an impact associated with the landing of the wheel on the track, Root mean square value calculation means for calculating the root mean square value of acceleration within a predetermined time width based on the acceleration detection value of the vertical vibration obtained from the acceleration sensor, First determination means for determining the root mean square value of acceleration before the impact detection by the impact detection means among the root mean square values of acceleration calculated by the root mean square value calculation means, Second determination means for determining the root mean square value of acceleration after the impact detection by the impact detection means among the root mean square values of acceleration calculated by the root mean square value calculation means, Root mean square value ratio calculation means for calculating the ratio of the root mean square value of acceleration before the impact detection determined by the first determination means to the root mean square value of acceleration after the impact detection determined by the second determination means, Derailment determination means for determining whether derailment has occurred based on the ratio of the root mean square values of acceleration calculated by the root mean square value ratio calculation means, and comprising: The root mean square value ratio calculation means stops the calculation process of the root mean square value ratio at a first predetermined time after the impact detection means detects an impact, The derailment determination means determines that derailment has occurred when the state where the ratio of the root mean square values of acceleration calculated by the root mean square value ratio calculation means exceeds a predetermined second threshold value set in advance continues for a second predetermined time or more. A derailment detection device for a railway vehicle characterized by this.

2. The first determination means determines, as the root mean square value of acceleration before impact detection, the maximum value within a predetermined acquisition time that is a predetermined setting time before the impact detection by the impact detection means among the root mean square values calculated by the root mean square value calculation means. The derailment detection device for a railway vehicle according to claim 1, characterized by this.

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 effective value calculation means calculates an effective acceleration value based on the data filtered by the second filter means. The derailment detection device for a railway vehicle according to claim 3.

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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