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 acceleration detection values of vertical oscillations acquired through acceleration sensors respectively installed on a front side vehicle frame and a rear side vehicle frame with a predetermined first threshold; effective value calculation means for calculating effective acceleration values within a predetermined time width on the basis of the acceleration detection values acquired through the acceleration sensors; average calculation means for calculating averages of the effective acceleration values for each vehicle frame; ratio calculation means for calculating ratios of the averages of the effective acceleration values, between the front side vehicle frame and the rear side vehicle frame, calculated after impact detection by the impact detection means; and derailment determination means for determining whether a derailment has occurred on the basis of the calculation result of the ratio calculation means. The derailment determination means determines the occurrence of the derailment when the ratio calculated by the 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 particularly relates to an effective technique 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. 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 them, 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 occurring. Therefore, there is a risk that a larger accident may occur than if the brakes were 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 at regular intervals, calculates the difference between the acquired integrated value and the integrated 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 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 performs derailment detection based on data acquired from a plurality of acceleration sensors installed on two bogie frames of one vehicle Shock detection means for detecting an impact associated with the landing of a wheel on a track by comparing the acceleration detection value of the vertical vibration acquired from an acceleration sensor installed on the front bogie frame and an acceleration sensor installed on the rear bogie frame with a predetermined first threshold value set in advance, Effective value calculation means for calculating the effective value of acceleration for each of the acceleration detection values of the vertical vibration acquired from the plurality of acceleration sensors within a predetermined time width based on the acceleration detection values of the vertical vibration acquired from the plurality of acceleration sensors, Average value calculation means for calculating, for each bogie frame, the average value of the effective values of acceleration calculated by the effective value calculation means based on the acceleration detection values of the plurality of acceleration sensors installed on the front bogie frame and the acceleration detection values of the plurality of acceleration sensors installed on the rear bogie frame, Ratio calculation means for calculating the ratio between the average value of the effective value of acceleration in the front bogie frame and the average value of the effective value of acceleration in the rear bogie frame calculated by the average value calculation means after the shock detection means detects a shock, Derailment determination means for determining whether or not derailment has occurred based on the result calculated by the ratio calculation means, and comprising, The ratio calculation means stops the calculation process of the ratio after a predetermined time from when the shock detection means detects a shock, The derailment determination means is configured to determine that derailment has occurred when the state where the ratio calculated by the ratio calculation means exceeds a predetermined second threshold value continues for a predetermined continuous time or more.

[0009] According to the derailment detection device for a railway vehicle having the above configuration, it is possible to make a determination of derailment detection 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, 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 impact detection means performs a process of detecting an impact for each bogie frame based on the acceleration detection value obtained from the acceleration sensor installed on the front bogie frame and the acceleration detection value obtained from the acceleration sensor installed on the rear bogie frame. The ratio calculation means is configured to calculate the ratio between the average value of the effective acceleration values in the front bogie frame calculated by the average value calculation means and the average value of the effective acceleration values in the rear bogie frame each time the impact detection means detects an impact. According to such a configuration, even if either the front bogie or the rear bogie of one vehicle derails first, the derailment can be detected promptly.

[0011] Furthermore, preferably, the acceleration sensor is an acceleration sensor installed on the front bogie frame and the rear bogie frame, and 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 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 a filter process for deriving impact acceleration on the data obtained from the acceleration sensor, and a second filter means for performing a filter process 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 acceleration value based on the data filtered by the second filter means.

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

[0014] Furthermore, preferably, the duration is set based on the duration 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, it is possible to prevent the derailment determination means from erroneously determining the occurrence of derailment when the vehicle is passing through a rail joint or a switch.

Advantages 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, the 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. Further, the bogie frame 30F shown in FIG. 1 is the bogie frame of the bogie on the front side in the traveling direction among the two bogies of one vehicle, and the bogie frame 30R indicates the bogie frame of the bogie on the rear side in the traveling direction.

[0018] As shown in FIG. 1, using the derailment detection device for a railway vehicle of the present embodiment, the derailment detection system includes a bogie monitoring device 20 that collects data from acceleration sensors 21F and 21R that detect the acceleration of vertical vibration respectively installed on the bogie frames 30F and 30R, and a derailment detection device 10 that reads the acceleration data among the data collected by the bogie monitoring device 20 and performs derailment detection.

[0019] Note that the existing bogie monitoring device 20 is configured to collect data not only from the acceleration sensors but also, for example, from pressure sensors provided on the air springs installed on the bogie frame 30F. The same applies to the bogie frame 30R. The derailment detection device 10 performs derailment detection using the data of the acceleration sensors 21F and 21R among the data collected by the bogie monitoring device 20.

[0020] The above derailment detection device 10 is mounted on a vehicle traveling on the rails of a railway track. When applying it to a vehicle not equipped with the bogie monitoring device 20, acceleration sensors 21F and 21R may be provided on the bogie frames 30F and 30R, and signals from these sensors may be directly input to the derailment detection device 10. Note that 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 unit 11 that determines whether a derailment has occurred based on the vertical acceleration data acquired from the acceleration sensors 21F and 21R, a storage device 12 that stores setting values and the like used for the derailment detection determination, 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 unit 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. Further, the arithmetic processing unit 11 is configured such that the program performs 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. Then, 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 the brake device 24.

[0023] The acceleration sensors 21F and 21R installed on the bogie frames 30F and 30R may be any sensors that can detect at least the acceleration in the vertical direction (vertical direction). A three-axis acceleration sensor may be used as the acceleration sensors 21F and 21R, 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 recall of the derailment detection algorithm of the present invention will be described. The inventors predicted that derailment could be detected by monitoring the vibration of the bogie because abnormal bogie vibration that far exceeds the bogie vibration during normal running occurs during derailment of the vehicle, and considered that it might be good to use a bogie frame acceleration sensor for vibration detection. In addition, since some existing vehicles are equipped with a bogie monitoring device having a bogie frame acceleration sensor, it was decided to conduct tests using the bogie frame acceleration sensor of that bogie monitoring device.

[0025] Specifically, the bogie was removed from the vehicle, and dead weights (equivalent to empty vehicle and full vehicle) were mounted on the test bogie so that the normal configuration of the vehicle and the load on the axle springs were the same. In addition, the outer springs were removed from the axle springs and only the inner springs were used. Further, a part of the rail on the track was removed, and derailment was simulated by dropping the test bogie placed on the rail from the rail onto the track. The lengths of the left and right rails were made different to change the landing timing of the left and right wheels, and a test was conducted to obtain the vibration 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 acceleration occurs at the time of wheel landing compared to when running on the rail. In addition, using the data of the acceleration sensor, the root mean square (RMS) of the acceleration of the vertical vibration was calculated every 0.2 seconds before and after wheel landing. As a result, it was found that a considerably large effective value of acceleration occurs when running on the track after derailment compared to when running on the rail.

[0027] As described above, it is considered that the ratio of the effective values of acceleration before and after derailment has a relatively large difference because the vibration during running is 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 effective value on the acceleration data obtained in time series from the acceleration sensor 21F provided on the front bogie frame, using preset filter coefficients respectively. Similarly, for the acceleration data obtained in time series from the acceleration sensor 21R provided on the rear bogie frame, filter processing (S1') for deriving impact acceleration and filter processing (S2') for deriving effective value are performed in parallel using preset filter coefficients respectively. Note that the filter processes S1, S2 (S1', S2') are performed to extract vibrations in a frequency band peculiar to derailment because there are differences in the acceleration frequency between normal running and derailment. The filter coefficients may be determined by comparing the respective vibration frequencies obtained from the acceleration sensor in advance in a track running test with those during rail running and finding the frequency band where differences occur.

[0029] Subsequently, for each of the front bogie frame 30F and the rear bogie frame 30R, impact determination processing (S3, S3') for determining whether there is an impact greater than or equal to a predetermined value using the acceleration filtered by S1, S1' and a preset threshold TH1 (detecting P2 in FIG. 2) and effective value calculation processing (S4, S4') for calculating the effective value (RMS) of the acceleration data of the front and rear bogies filtered by S2, S2' are executed, for example, every 0.2 seconds. In the above impact determination processing (S3, S3'), the impact may be determined based on whether the "ratio" with the immediately preceding acceleration exceeds a preset threshold. Since the threshold TH1 in the above impact determination processing (S3, S3') varies depending on the vehicle to which the present invention is applied and the track on which it runs, it is advisable to determine an appropriate value through experiments in advance.

[0030] Next, the average value calculation processes (S5, S5') for calculating the average of the effective acceleration values of the acceleration sensor 21F of the front bogie and the average of the effective acceleration values of the acceleration sensor 21R of the rear bogie are executed in parallel. Subsequently, the processes (S6, S6') for calculating the ratios of the average values of the effective values of the acceleration sensors of the front bogie and the rear bogie calculated in S5 (average effective value of the front bogie / average effective value of the rear bogie) and (average effective value of the rear bogie / average effective value of the front bogie) are executed respectively.

[0031] On the other hand, when it is determined in the impact determination processes (S3, S3') that an impact has occurred, a timer is started, and the time measurement processes (S7, S7') for a preset determination off-delay time (for example, 5 seconds) are performed. When the determination off-delay time has elapsed, the average value calculation processes (S5, S5') of the effective values of the acceleration data and the processes (S6, S6') for calculating the ratio of the average values are stopped. Here, the timing for determining that an impact has occurred in the impact determination processes (S3, S3') is different between the front bogie frame and the rear bogie frame. However, cases where the front bogie frame derails first, the rear bogie frame derails first, or only one of the front bogie frame and the rear bogie frame derails are also assumed.

[0032] Therefore, when it is determined in the impact determination processes (S3, S3') that an impact has occurred, using this as a trigger, a derailment determination process (S8) is executed to determine whether derailment has occurred based on whether a state where the ratio (magnification) of the average effective values calculated in the process (S6, S6') for calculating the ratio of the average values exceeds a preset magnification threshold has continued for a preset duration or more. Specifically, when the front bogie frame derails first or only the front bogie frame derails, as shown in Fig. 4, the amplitude of the acceleration detected by the acceleration sensor of the front bogie frame is greater than the amplitude of the acceleration detected by the acceleration sensor of the rear bogie frame. Therefore, when the state where the ratio (multiplication factor) of the effective value average value is greater than the threshold value continues for a predetermined time, it is determined that derailment has occurred. Also, when the rear bogie frame derails first or only the rear bogie frame derails, conversely to Fig. 4, the amplitude of the acceleration detected by the acceleration sensor of the rear bogie frame is greater than the amplitude of the acceleration detected by the acceleration sensor of the front bogie frame. Therefore, in the derailment determination process (S8), such derailment occurrence can be determined from the ratio of the effective value of the acceleration.

[0033] Note that the "continuous time" used in the above derailment determination process (S8) 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 acquired 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] Also, the above derailment determination process (S8) is performed at the time when the determination off-delay time has elapsed from the timing when impact occurrence is determined in the impact determination process for the front bogie frame, and at the time when the determination off-delay time has elapsed from the timing when impact occurrence is determined in the impact determination process for the rear bogie frame. And when derailment detection is determined in any of the determination processes, the derailment detection device 10 notifies the running control device 22 of the derailment detection, and the running control device 22 performs control to operate the brake device 24 to decelerate the vehicle.

[0035] 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, it is possible to equip the vehicle with a derailment detection function without causing a significant cost increase.

[0036] 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 ratio of the average value of the effective values calculated from the accelerations detected by the acceleration sensors installed on the front and rear bogie frames. However, derailment detection may be performed based on the ratio of the average values of the accelerations before calculating the effective values.

Explanation of Reference Numerals

[0037] 10 Derailment detection device 11 Arithmetic processing device (arithmetic means) 12 Storage device (storage means) 13 Communication device 20 Bogie monitoring device (data collection means) 21F, 21R Acceleration sensors 22 Travel control device 30F, 30R Bogie frames

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 acquired from a plurality of acceleration sensors installed on two bogie frames of one vehicle, Impact detection means for comparing the acceleration detection value of the vertical vibration acquired from the acceleration sensor installed on the front bogie frame and the acceleration sensor installed on the rear bogie frame with a preset first threshold value to detect an impact caused by the landing of the wheel on the track; Effective value calculation means for calculating the effective value of acceleration for each of the plurality of acceleration sensors acquired from the vertical vibration in a predetermined time width based on the acceleration detection value; Average value calculation means for calculating the average value of the effective value of acceleration calculated by the effective value calculation means for each of the bogie frames based on the acceleration detection values of the plurality of acceleration sensors installed on the front bogie frame and the acceleration detection values of the plurality of acceleration sensors installed on the rear bogie frame; Ratio calculation means for calculating the ratio between the average value of the effective value of acceleration in the front bogie frame calculated by the average value calculation means and the average value of the effective value of acceleration in the rear bogie frame after the impact detection means detects an impact; Derailment determination means for determining whether or not derailment has occurred based on the result calculated by the ratio calculation means, comprising: The ratio calculation means stops the calculation process of the ratio after a predetermined time from when the impact detection means detects an impact, The derailment determination means determines that derailment has occurred when the state where the ratio calculated by the ratio calculation means exceeds a predetermined second threshold value continues for a predetermined continuous time or more. A derailment detection device for a railway vehicle characterized by this.

2. The impact detection means performs a process of detecting an impact for each of the bogie frames based on the acceleration detection value acquired from the acceleration sensor installed on the front bogie frame and the acceleration detection value acquired from the acceleration sensor installed on the rear bogie frame, The ratio calculation means calculates the ratio between the average value of the effective acceleration value in the front bogie frame calculated by the average value calculation means and the average value of the effective acceleration value in the rear bogie frame each time the impact detection means detects an impact. The derailment detection device for a railway vehicle according to claim 1, characterized in that.

3. The acceleration sensor is an acceleration sensor installed on the front bogie frame and the rear bogie frame. The impact detection means compares the value of the acceleration detected by the acceleration sensor with the first threshold value to detect an impact associated with the landing of the wheel. The derailment detection device for a railway vehicle according to claim 1 or 2, characterized in that.

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 is provided with. 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 calculates the 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, characterized in that.

5. The duration is set based on the time during which the impact obtained in advance at a location where rail joints are continuous or at a switch during normal running continues. The derailment detection device for a railway vehicle according to claim 4, characterized in that.

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