JP5662298B2 - Anomaly detection method and anomaly detection apparatus for pillow spring system - Google Patents

Description

  The present invention relates to an abnormality detection method and an abnormality detection apparatus for a pillow spring system provided between a vehicle body and a carriage of a railway vehicle.

A general railway vehicle includes a primary spring system provided between a axle box supporting a wheel shaft and a carriage frame, and a secondary spring system provided between the carriage frame and the vehicle body.
The secondary spring system includes a pillow spring that is a spring element such as an air spring, and a pillow spring damper that generates a damping force in accordance with the expansion and contraction of the pillow spring.
In addition, a pillow spring itself made of, for example, an air spring may also serve as a damping element.

In order to ensure the safety and riding comfort of railway vehicles, it is possible to properly detect pillow spring system abnormalities such as the above-mentioned pillow spring system damping elements that do not generate damping force or air spring pressure drop. It is requested.
For example, Patent Document 1 discloses a technique for determining an abnormality when an output of acceleration detection means provided on a carriage exceeds a predetermined threshold as a conventional technique related to an abnormality detection of a railway carriage.
Further, Patent Document 2 describes that abnormality is determined based on a change in average acceleration power obtained by sampling vibration acceleration of a carriage or the like at equidistant intervals and squared after bandpass filter processing.

Japanese Patent Laid-Open No. 2000-6807 Japanese Patent No. 4252271

For example, it is also conceivable to apply the conventional technology relating to the detection of an abnormality of the carriage as described above to the pillow spring system, and to detect the abnormality of the damping element and the spring element of the pillow spring system based on the change in the vibration acceleration of the vehicle body.
However, even if the damping element or the spring element fails, the acceleration change of the vehicle body itself is often very small, and in order to perform appropriate detection in such a method, the threshold value needs to be considerably reduced. it is conceivable that. However, if the threshold value is reduced in this way, for example, when passing through a portion having a large orbital irregularity, there is a concern that it may be erroneously determined to be abnormal although the damping element and the spring element are normal.
In view of the above-described problems, an object of the present invention is to provide an abnormality detection method and an abnormality detection device for a pillow spring system that can appropriately detect an abnormality during operation of a vehicle.

A pillow spring system abnormality detection method of the present invention that solves the above-described problem is a pillow spring system abnormality detection method provided between a vehicle body and a carriage of a railway vehicle, wherein the vertical acceleration and pitching of the vehicle body are detected. A direction acceleration is detected, and when the phase difference between the vertical direction acceleration and the pitching direction acceleration is out of a predetermined allowable range, it is determined as abnormal.
Here, the pillow spring system includes a spring element and a damping element. The damping element is not limited to a damper such as a hydraulic shock absorber provided separately from the spring element, and the spring element itself, for example, an air spring, serves as the damping element. Including those that also served.
According to this, the phase difference between the vertical acceleration of the vehicle body and the acceleration in the pitching direction changes depending on whether the pillow spring system is normal or abnormal, so that the abnormality is detected when this phase difference is outside a predetermined allowable range. By determining, abnormality of the pillow spring system can be detected appropriately during operation of the vehicle.
In this invention, it can be set as the structure which specifies the site | part of the pillow spring type | system | group in which abnormality generate | occur | produced based on the direction where the said phase difference was outside the said tolerance | permissible_range.

In the present invention, a predetermined frequency band component set in advance is extracted from the vertical acceleration and the pitching acceleration, and the phase difference between the vertical acceleration and the pitching acceleration after the extraction is within a predetermined allowable range. It can be set as the structure judged to be abnormal when it comes off.
According to this, it is possible to detect the abnormality of the pillow spring system more appropriately by extracting the frequency band in which the phase difference tends to increase between the normal time and the abnormal time.
In this case, the predetermined frequency band may be set to include the natural frequency of the vibration in the vertical translation mode of the vehicle body.
According to this, since the natural frequency of the vertical translation mode of the vehicle body is likely to be different in phase difference between when the pillow spring system is normal and when it is abnormal, abnormality detection can be performed more reliably.
In this case, the predetermined frequency band can be shifted to the high frequency side in accordance with an increase in travel speed.
According to this, even when the traveling speed changes and the frequency band in which the difference in phase difference is likely to occur between when the pillow spring system is normal and when it is abnormal, abnormality detection can be performed appropriately. .

In this invention, it can be set as the structure which correct | amends at least one of the said phase difference and the said tolerance | permissible_range according to driving | running | working speed using the correlation of the driving speed in the normal time calculated | required previously, and the said phase difference.
According to this, the phase difference tends to depend on the traveling speed even when it is normal, but such an influence can be reduced to appropriately detect an abnormality.

In the present invention, the vertical acceleration and the pitching direction acceleration after extracting the components of the predetermined frequency band are converted into codes, and based on a mismatch rate between the code of the vertical acceleration and the code of the pitching direction acceleration. The phase difference can be detected.
According to this, by using the mismatch rate of the signs of vertical acceleration and pitching direction acceleration as a parameter (approximate phase difference) indicating the magnitude of the phase difference, the calculation load is reduced, and a relatively simple device It is possible to perform computations at high speeds or at high speeds.
In this case, when the mismatch rate of the code is out of the allowable range, it is determined that there is an abnormality, and the mismatch rate and the allowable range are determined using the correlation between the normal travel speed obtained in advance and the mismatch rate. It can be set as the structure which correct | amends at least one of these according to traveling speed.
According to this, it is possible to appropriately detect an abnormality while reducing the influence of the dependency of the code mismatch rate on the traveling speed.

In this invention, it can be set as the structure which calculates | requires the said phase difference based on the cross spectrum which carried out the Fourier transformation of the cross correlation function of the said vertical direction acceleration and the said pitching direction acceleration.
According to this, although the calculation load increases as compared with the case of obtaining the code mismatch rate, the abnormality detection accuracy can be increased.

In the present invention, the abnormality detection can be performed when the traveling speed is included in the preset abnormality detection speed range, and the abnormality detection can be stopped when the traveling speed is out of the abnormality detection speed range. .
According to this, for example, when it is difficult to detect an abnormality by the method of the present invention such as when traveling at low speed, it is possible to prevent erroneous detection.

A pillow spring system abnormality detection device of the present invention that solves the above-described problem is a pillow spring system abnormality detection device provided between a vehicle body and a carriage of a railway vehicle, wherein the vertical acceleration of the vehicle body, and Vehicle body behavior detecting means for detecting the acceleration in the pitching direction, and an abnormality detecting means for determining that the phase difference between the vertical acceleration and the pitching direction acceleration is out of a predetermined allowable range. To do.
In the present invention, the abnormality detection means may be configured to identify a part of a pillow spring system in which an abnormality has occurred based on a direction in which the phase difference is outside the allowable range.

In the present invention, a frequency band extracting unit that extracts a predetermined frequency band component set in advance from the vertical direction acceleration and the pitching direction acceleration is provided, and the abnormality detection unit includes the vertical direction acceleration after the extraction and the When the phase difference from the acceleration in the pitching direction is out of a predetermined allowable range, it can be determined as abnormal.
In this case, the predetermined frequency band may be set to include the natural frequency of the vibration in the vertical translation mode of the vehicle body.
In this case, the frequency band extracting means can be configured to shift the predetermined frequency band to a higher frequency side in accordance with an increase in travel speed.

  In the present invention, the abnormality detection means corrects at least one of the phase difference and the allowable range according to the traveling speed using a correlation between a normal traveling speed obtained in advance and the phase difference. can do.

In the present invention, there is provided conversion means for converting the vertical direction acceleration and the pitching direction acceleration after extracting the component of the predetermined frequency band into a sign, and the abnormality detecting means includes the sign of the vertical direction acceleration and the pitching direction. The phase difference can be detected based on a mismatch rate with the sign of acceleration.
In this case, the abnormality detection means determines that an abnormality occurs when the code mismatch rate is out of an allowable range, and uses the correlation between the normal travel speed obtained in advance and the mismatch rate, It can be set as the structure which correct | amends at least one of a mismatch rate and the said tolerance | permissible_range according to driving speed.

  In the present invention, the abnormality detection means may be configured to obtain the phase difference based on a cross spectrum obtained by Fourier transforming the cross-correlation function of the vertical acceleration and the pitching acceleration.

  In the present invention, the abnormality detection means detects abnormality when the traveling speed is included in a preset abnormality detection speed range, and stops abnormality detection when the traveling speed is out of the abnormality detection speed range. It can be configured.

  In the present invention, the vehicle body behavior detecting means is arranged apart from the traveling direction of the vehicle, detects a vertical acceleration of the vehicle body, and outputs the vehicle body based on the outputs of the plurality of acceleration sensors. It can be set as the structure provided with the pitching direction acceleration calculating means which calculates a pitching direction acceleration.

  In this invention, the said vehicle body behavior detection means can be set as the structure which has an acceleration sensor which detects the vertical direction acceleration of the said vehicle body, and an angular velocity sensor which detects the pitching direction acceleration of the said vehicle body.

  As described above, according to the present invention, it is possible to provide an abnormality detection method and an abnormality detection device for a pillow spring system that can appropriately detect an abnormality during operation of a vehicle.

It is a schematic diagram which shows the structure of 1st Embodiment of the abnormality detection apparatus of the pillow spring system to which this invention is applied. It is a graph which shows an example of the phase difference of the vertical direction acceleration of a vehicle body, and a pitching direction acceleration when a pillow spring damper is normal or abnormal. It is a graph which shows an example of the acceleration log | history of the vehicle body of a vertical translation mode and a pitching mode. It is a graph which shows an example of the acceleration history of the body of the up-and-down translation mode and pitching mode after passing a band pass filter. It is a graph which shows an example of the log | history of the code | symbol of the acceleration of the vehicle body of the up-down translation mode and pitching mode after passing a band pass filter. It is a graph which shows an example of the log | history of the exclusive OR (XOR) of the code | symbol of the acceleration of the vehicle body of the up-down translation mode after a band pass filter, and a pitching mode. It is a graph which shows an example of the value (code mismatch rate) which averaged the exclusive OR (XOR) of the code | symbol of the acceleration of the vehicle body of a vertical translation mode and a pitching mode through a low-pass filter. It is a graph which shows an example of transition of the code mismatch rate at the time of normal time and abnormal time, Comprising: The pillow spring damper shows the case where it is a semi-active damper. It is a graph which shows an example of transition of the code mismatch rate at the time of normal and abnormal time, Comprising: The pillow spring damper shows the case where it is a passive damper. It is a schematic diagram which shows the structure of 2nd Embodiment of the pillow spring type abnormality detection apparatus to which this invention is applied. It is a graph which shows an example of the change of the phase difference of the up-down direction acceleration and pitching direction acceleration of the vehicle body according to the running speed of the vehicle. It is a graph which shows the relationship between the code | symbol mismatch rate at the time of a pillow spring damper normal, and driving speed. It is a graph which shows an example of transition of the code mismatch rate at the time of normal time, the time of the 1st truck right abnormality, and the time of the 2nd truck right abnormality. It is a graph which shows what made the data of FIG. 13 the relative value on the basis of the approximate function shown in FIG. It is a graph which shows an example in the case of changing a threshold value according to the fluctuation | variation of a code mismatch rate.

<First Embodiment>
Hereinafter, a pillow spring system abnormality detection method to which the present invention is applied and a first embodiment of an abnormality detection apparatus used in the abnormality detection method will be described.
As shown in FIG. 1, the railway vehicle 1 provided with the abnormality detection device 100 is a bogie vehicle including a first bogie 20 and a second bogie 30 that are a pair of bogies before and after a vehicle body 10.
The vehicle body 10 is formed in a substantially hexahedron shape by providing a side frame, a wife frame, a roof frame, and the like on the upper part of a frame provided on the floor.

The first carriage 20 and the second carriage 30 are sequentially arranged from the front side in the traveling direction of the vehicle 1.
The first bogie 20 includes a bogie frame 21, a first wheel shaft 22, a second wheel shaft 23, a secondary spring system 24, and the like.
The bogie frame 21 is a frame-like structural member to which the first wheel shaft 22 and the second wheel shaft 23 are attached via a shaft box and a shaft box support device.
The first wheel shaft 22 and the second wheel shaft 23 are obtained by fixing a pair of wheels to both ends of an axle.
The first wheel shaft 22 and the second wheel shaft 23 are sequentially arranged from the front side in the traveling direction of the vehicle 1.
The first wheel shaft 22 and the second wheel shaft 23 are supported by shaft boxes (not shown) at both ends of the axle. The axle box includes a bearing and a lubrication device.
The axle box is supported via an axle box support device (not shown) so as to be relatively displaceable in the vertical direction with respect to the carriage frame 21.
The shaft box support device includes a shaft spring that generates a spring reaction force according to the vertical displacement of the shaft box relative to the carriage frame 21 and a primary spring that includes a shaft damper that generates a damping force according to the expansion and contraction speed of the shaft spring. A system is provided.

The second bogie 30 includes a bogie frame 31, a third wheel shaft 32, a fourth wheel shaft 33, a secondary spring system 34, and the like.
The cart frame 31 is a frame-like structural member to which the third wheel shaft 32 and the fourth wheel shaft 33 are attached via a shaft box and a shaft box support device.
The third wheel shaft 32 and the fourth wheel shaft 33 are obtained by fixing a pair of wheels to both ends of the axle.
The third wheel shaft 32 and the fourth wheel shaft 33 are sequentially arranged from the front side in the traveling direction of the vehicle 1.
The third wheel shaft 32 and the fourth wheel shaft 33 are supported by shaft boxes (not shown) at both ends of the axle. The axle box includes a bearing and a lubrication device.
The axle box is supported via an axle box support device (not shown) so as to be relatively displaceable in the vertical direction with respect to the carriage frame 31.
The axle box support device includes an axial spring that generates a spring reaction force corresponding to the vertical displacement of the axle box relative to the carriage frame 31, and a primary spring that includes an axial damper that generates a damping force corresponding to the expansion and contraction speed of the axle spring. A system is provided.

The carriage frames 21 and 31 of the first carriage 20 and the second carriage 30 are attached to the lower part of the vehicle body 10 via secondary spring systems 24 and 34.
The secondary spring systems 24 and 34 include a pillow spring (not shown) and pillow spring dampers 24a and 34a provided in parallel with the pillow spring.
The pillow spring is a spring element such as an air spring that generates a spring reaction force corresponding to the vertical displacement of the carriage frames 21 and 31 relative to the vehicle body 10.
The pillow spring dampers 24 a and 34 a are damping elements such as hydraulic shock absorbers that generate a damping force corresponding to the vertical relative speed of the carriage frames 21 and 31 with respect to the vehicle body 10.
The pillow spring dampers 24a and 34a are semi-active dampers that can change the damping force characteristics at any time during traveling in accordance with a command from a vertical vibration control system (not shown).
For example, a pair of pillow springs and pillow spring dampers 24a and 34a are provided in the bogie frames 21 and 31 so as to be separated from each other in the sleeper direction.

The abnormality detection apparatus 100 according to the first embodiment detects an abnormality in which the pillow spring dampers 24a and 34a described above do not normally generate a damping force.
The abnormality detection device 100 includes a processing device 110, acceleration sensors 121 and 122, and the like.
The processing device 110 includes, for example, an information processing device such as a CPU, RAM, ROM, storage means such as a magnetic disk device or an optical disk device, an input / output interface, and a bus connecting them.
The processing device 110 is an abnormality detection unit that processes a signal from each sensor as described later and detects an abnormality.
The acceleration sensors 121 and 122 are arranged on the left-right center line of the vehicle body 10 so as to be separated from each other in the front-rear direction, and include an acceleration pickup that detects the vertical acceleration of the vehicle body 10.
For example, the acceleration sensors 121 and 122 are suspended from the floor of the vehicle body 10.
The acceleration sensor 121 is disposed in the vicinity of the first carriage 20.
The acceleration sensor 122 is disposed in the vicinity of the second carriage 30.
Output signals of the acceleration sensors 121 and 122 are transmitted to the processing device 110.

Hereinafter, the abnormality detection method for the pillow spring damper according to the first embodiment will be described.
In this abnormality detection method, the following procedure is performed when the traveling speed of the vehicle 1 is included in a preset abnormality detectable range.
(1) The acceleration sensors 121 and 122 measure vertical accelerations at two points separated in the traveling direction in the vehicle body 10.
(2) The vertical acceleration detected by the acceleration sensors 121 and 122 is separated into the vertical translation mode acceleration and the pitching mode acceleration.
(3) The sign of the acceleration in the pitching mode is changed according to the traveling direction of the vehicle.
(4) The phase difference between the acceleration in the vertical translation mode and the acceleration in the pitching mode at a specific frequency described later is detected. This specific frequency is a frequency at which a large difference in phase difference occurs between the normal time and the abnormal time, and is obtained in advance through experiments or the like.
(5) When the phase difference is outside the preset allowable range, it is determined that the pillow spring dampers 24a and 34a are abnormal.
At this time, it is determined whether an abnormality has occurred in the pillow spring dampers 24a, 34a of the first carriage 20 or the second carriage 30 depending on whether the allowable range is exceeded on the plus side or the minus side.

In addition, the above-described calculation of the phase difference can be performed based on, for example, a cross spectrum obtained by Fourier-transforming the cross-correlation function of the vertical direction acceleration and the pitching direction acceleration. In order to reduce the load, the phase difference is approximately obtained in the following directions.
(1) A specific frequency component is extracted by passing the vertical acceleration and the pitching acceleration through band-pass filters.
(2) The vertical acceleration and the pitching acceleration after passing through the band pass filter are binarized with 0 as a threshold value. For example, it is 1 if the sign is positive, and 0 if the sign is negative.
(3) An exclusive OR (XOR) of the binarized vertical acceleration and the pitching direction acceleration is taken. Thereby, at each timing, it is determined whether or not the signs of the vertical acceleration and the pitching direction acceleration match.
(4) With respect to the exclusive OR described above, an average value within a predetermined time period is obtained or smoothed through a low-pass filter to obtain a sign mismatch rate between the vertical acceleration and the pitching acceleration.
Here, when the vertical acceleration and the pitching acceleration are periodic signals, if the phase difference between the two is 0 °, the sign mismatch rate is zero. If the phase difference is ± 180 °, the code mismatch rate is 1. Actually, the vertical acceleration and the pitching acceleration are not completely periodic signals, but the sign mismatch rate can be used as a parameter that approximately represents the phase difference.

Hereinafter, the numerical simulation result by one vehicle model is demonstrated.
In this simulation, for example, the measured waveform of the vertical acceleration in the axle box during traveling at 75 km / h was input to the vehicle model. In this vehicle model, the pillow spring dampers 24a and 34a are variable damping dampers whose damping characteristics can be changed during traveling, and simulate the control state by a known vertical vibration damping system. Further, the abnormal state of the pillow spring dampers 24a and 34a is a state in which the variable damping damper is fixed to the minimum damping.

First, the frequency at which a large difference in the phase difference between normal and abnormal is examined, and the frequency band to be noticed in abnormality detection is determined.
FIG. 2 is a graph showing the result of obtaining the phase difference between vibrations in the vertical translation mode and the pitching mode of the vehicle body from the cross spectrum, where the horizontal axis indicates the frequency and the vertical axis indicates the phase difference. Further, in FIG. 2, the data when the right pillow spring damper 24a of the first carriage 20 fails and when the right pillow spring damper 34a of the second carriage 30 fails are shown by a solid line, a dotted line, and a one-dot chain line, respectively. ing.
As shown in FIG. 2, the phase difference is significantly different between normal and abnormal in the vicinity of 1.5 Hz, which is also near the natural frequency of the vehicle body 10.
Therefore, in the first embodiment, an abnormality is detected using the frequency component in the vicinity of 1.5 Hz.

FIG. 3 is a graph showing an example of the transition of acceleration obtained by mode separation of the vertical acceleration at two points of the vehicle body 10 detected by the acceleration sensors 121 and 122.
FIG. 3A shows the acceleration in the up / down translation mode, and FIG. 3B shows the acceleration in the pitching mode.
In both FIG. 3A and FIG. 3B, the vertical axis indicates acceleration, and the horizontal axis indicates time.

FIG. 4 is a graph showing a result of passing the acceleration shown in FIG. 3 through a band-pass filter that passes the vicinity of 1.5 Hz.
FIG. 4A shows the acceleration in the up / down translation mode, and FIG. 4B shows the acceleration in the pitching mode.
In both FIG. 4A and FIG. 4B, the vertical axis indicates acceleration, and the horizontal axis indicates time.

FIG. 5 shows a history of acceleration codes obtained by binarizing the acceleration in the vertical translation mode and the pitching mode after passing through the bandpass filter shown in FIGS. 4A and 4B, with 0 as a threshold value as described above. It is a graph to show.
5A shows the acceleration code in the up / down translation mode, and FIG. 5B shows the acceleration code in the pitching mode.
In both FIG. 5A and FIG. 5B, the vertical axis indicates the acceleration code, and the horizontal axis indicates time.

FIG. 6 is a graph showing an exclusive OR (XOR) history of the acceleration code in the up / down translation mode and the acceleration code in the pitching mode shown in FIG.
In FIG. 6, the vertical axis represents the exclusive OR of acceleration codes (1: different code, 0: same code), and the horizontal axis represents time.

FIG. 7 is a graph showing a history of results (sign mismatch rate) obtained by passing the exclusive OR shown in FIG. 6 through a low-pass filter to obtain an average value within a predetermined period.
In FIG. 7, the vertical axis indicates the code mismatch rate and the horizontal axis indicates time.
This code mismatch rate represents an approximate phase difference between accelerations in the vertical translation mode and the pitching mode.

FIG. 8 shows the result of calculating the code mismatch rate between the normal time and the abnormal time using the vehicle model described above.
In FIG. 8, the vertical axis indicates the sign mismatch rate, the horizontal axis indicates time, the normal state, the abnormal state of the right pillow spring damper 24a of the first cart 20, the abnormal state of the left pillow spring damper 24a of the first cart 20, The abnormal state of the right pillow spring damper 34a of the two carriages 30 and the abnormal state of the left pillow spring damper 34a of the second carriage 30 are respectively illustrated by a solid line, a dotted line, a one-dot chain line, a two-dot chain line, and a three-dot chain line (a figure to be described later). 9).

As shown in FIG. 8, the sign mismatch rate is stable in the vicinity of 0.55 when normal, but when the pillow spring damper 24a of the first carriage 20 is abnormal, the sign mismatch rate (approximate phase difference) is larger than normal. In addition, when the pillow spring damper 34a of the second carriage 30 is abnormal, it is understood that the sign mismatch rate is smaller than normal.
In this case, for example, if 0.5 to 0.6 is set as the permissible range, it is determined that there is an abnormality when the permissible range is deviated. Can be identified.
Here, since the initial value of the filter is set to 0.55, the calculation start (0 seconds) is 0.55 in all cases.

FIG. 9 is a graph showing calculation results when the pillow spring damper is a passive damper having a fixed damping force characteristic.
As shown in FIG. 9, the difference between the normal time and the abnormal time is reduced with respect to the vertical vibration suppression control state shown in FIG. 8, but the tendency is common, and by appropriately setting the threshold value, It is possible to detect an abnormality of the pillow spring damper in units of carts.

As described above, according to the first embodiment, the following effects can be obtained.
(1) The phase difference between the vertical acceleration and the pitching direction acceleration of the vehicle body 10 changes depending on whether the pillow spring dampers 24a and 34a are normal or abnormal. Therefore, when this phase difference is outside a predetermined allowable range. By determining the abnormality, it is possible to appropriately detect the abnormality of the pillow spring dampers 24a and 34a during the operation of the vehicle 1.
Furthermore, it is possible to determine which of the pillow spring dampers 24a and 34a is abnormal depending on which side of the phase difference is outside the allowable range.
(2) By using the vertical direction acceleration and the pitching direction acceleration through a band-pass filter in the vicinity of 1.5 Hz where the difference between normal and abnormal is large and then using it for abnormality detection, the pillow spring damper 24a, The abnormality 34a can be detected.
(3) By using the sign mismatch rate between the vertical acceleration and the pitching direction acceleration after passing through the bandpass filter as a parameter (approximate phase difference) indicating the magnitude of the phase difference, the calculation load is reduced. It is possible to calculate with a simple device or to calculate at high speed.

Second Embodiment
Next, a second embodiment of the pillow spring system abnormality detection apparatus to which the present invention is applied will be described.
In the description of each embodiment described below, portions that are substantially the same as those in the previous embodiment are denoted by the same reference numerals, description thereof is omitted, and differences are mainly described.
The abnormality detection device 100A according to the second embodiment includes an acceleration sensor 123 and a gyro sensor 130 that are arranged at the center under the floor of the vehicle body 10 instead of the acceleration sensors 121 and 122 according to the first embodiment.

In the first embodiment, the acceleration in the vertical translation mode and the pitching mode is detected by the mode separation of the vertical acceleration detected by the pair of acceleration sensors 121 and 122. In the second embodiment, the acceleration sensor 123 detects the vertical motion. The acceleration in the translation mode is detected, and the angular acceleration in the pitching direction is detected by the gyro sensor 130.
Also in the second embodiment described above, substantially the same effect as the effect of the first embodiment described above can be obtained.

<Third Embodiment>
Next, a third embodiment of a pillow spring type abnormality detection apparatus to which the present invention is applied will be described.
In the third embodiment, in view of the fact that the frequency band in which the phase difference is likely to be different between the normal state and the abnormal state of the pillow spring system is around the natural frequency of the vibration in the vertical translation mode of the vehicle body. A frequency band around several times is extracted by a band pass filter to detect anomalies. In this case, as in each of the embodiments described above, it is not always necessary to determine the cut-off frequency by obtaining the phase difference of the cross spectrum.

FIG. 11 is a graph showing an example of a change in the phase difference between the vertical acceleration of the vehicle body and the acceleration in the pitching direction according to the traveling speed of the vehicle.
As shown in FIG. 11, it is known that the phase difference is inverted by 180 ° with a certain frequency as a boundary, and the frequency is proportional to the traveling speed.
For this reason, when the frequency band extracted by the bandpass filter is constant, both reversed phase differences are mixed depending on the traveling speed, and a stable code mismatch rate cannot be obtained.

ここで、ｘはフィルタ通過前の信号、ｙはフィルタ通過後の信号、ａ_１及びｂ_１は低速度用フィルタの係数、ａ_２及びｂ_２は高速度用フィルタの係数、ζは補間係数である。
なお、このように走行速度に応じて抽出する周波数帯域を変化させる場合であっても、例えば走行速度が極低速の場合等には、本手法による異常検出は困難である。
そこで、第３実施形態においては、走行速度が所定値以上の場合にのみ異常検出を行なうとともに、所定値未満の場合には異常検出を停止するようにしている。 Therefore, in the third embodiment, the cut-off frequency of the bandpass filter is changed in proportion to the traveling speed.
In this way, the filter whose cutoff frequency changes according to the traveling speed can be approximated by, for example, designing two bandpass filters having different cutoff frequencies and linearly interpolating between these filter coefficients. It is possible to realize. If such a method is used, the calculation load can be reduced, for example, compared to calculating the filter coefficient every time.
An example of the configuration of such a filter is shown in Equations 1 to 3.

Where x is the signal before passing through the filter, y is the signal after passing through the filter, a ₁ and b ₁ are the coefficients of the low speed filter, a ₂ and b ₂ are the coefficients of the high speed filter, and ζ is the interpolation coefficient is there.
Even when the frequency band to be extracted is changed according to the traveling speed in this way, for example, when the traveling speed is extremely low, it is difficult to detect an abnormality by this method.
Therefore, in the third embodiment, abnormality detection is performed only when the traveling speed is equal to or higher than a predetermined value, and abnormality detection is stopped when the traveling speed is lower than the predetermined value.

Further, the code and the code mismatch rate tend to vary depending on the traveling speed even at normal time, and this variation sometimes makes it difficult to determine abnormality.
Therefore, in the third embodiment, the relationship between the traveling speed and the code mismatch rate is approximated by a function based on the travel data acquired in advance, and the code mismatch rate relative to this approximate function is used as an evaluation value. Therefore, the influence of the traveling speed is reduced and the abnormality detection accuracy is increased.

FIG. 12 is a graph showing the relationship between the sign mismatch rate and the traveling speed when the damper is normal, acquired in the traveling test. In order to grasp the average tendency, moving average processing is performed for both the code mismatch rate and the traveling speed.
From FIG. 12, the sign mismatch rate depends on the traveling speed, and tends to increase as the speed decreases.
Here, the relationship between the traveling speed v (t) and the sign mismatch rate y (t) is approximated by a quadratic function as shown in Equation 4.

y _o = av (t) ² + bv (t) + c (Expression 4)

In the case of FIG. 12, the approximate function (Formula 5) shown by the thick solid line in FIG. 12 was obtained.

y _o = 0.0020797v ² −0.0359v + 1.8268 (Equation 5)

FIG. 13 is a graph showing an example of the transition of the code mismatch rate during normal operation, when the first vehicle right is abnormal, and when the second vehicle right is abnormal.
FIG. 14 is a graph showing the data in FIG. 13 as relative values based on the approximate function shown in FIG.
As shown in FIG. 14, by detecting the abnormality using the relative code mismatch rate y _r (t) from the approximate function y ₀ (t), the influence of the dependency of the code mismatch rate on the traveling speed is suppressed, and the abnormality is detected. It is possible to improve detection accuracy.
This relative code mismatch rate y _r (t) is shown in Equation 6.

y _r (t) = y (t) −y _o (t)
= Y (y)-(av (t) ² + bv (t) + c) (Equation 6)

Further, instead of using the sign mismatch rate as a relative value, a threshold value (allowable range) used for detecting an abnormality may be varied according to the traveling speed.
FIG. 15 is a graph illustrating an example in which the threshold value is changed in accordance with a change in the code mismatch rate.
In the example shown in FIG. 15, and the relative value of the approximate function y ₀ code mismatch ratio of the normal threshold.
As a result, the threshold value changes according to the traveling speed, and the threshold value can be changed to follow the fluctuation of the code mismatch rate.

In the third embodiment described above, the following effects can be obtained in addition to the effects substantially similar to the effects of the above-described embodiments.
(1) By detecting the frequency band around the natural frequency of the vertical vibration of the vehicle body and using it for abnormality detection, abnormality detection can be performed reliably.
(2) By shifting the frequency band to be extracted to the high frequency side in proportion to the traveling speed, appropriate abnormality detection can be performed regardless of the variation in the traveling speed.
(3) By configuring such a bandpass filter by linearly interpolating the coefficients of a plurality of filters having different cutoff frequencies, it is possible to reduce the calculation load.
(4) By stopping abnormality detection when the traveling speed is equal to or lower than a predetermined value, it is possible to prevent erroneous detection by performing abnormality detection, for example, at an extremely low speed that is not suitable for abnormality detection by this method.
(5) By correcting the code mismatch rate or the threshold according to the travel speed, it is possible to reduce the influence of the dependency of the code mismatch rate on the travel speed and increase the abnormality detection accuracy.

(Other embodiments)
In addition, this invention is not limited only to above-described embodiment, Various application and deformation | transformation can be considered.
For example, the detailed configurations of the abnormality detection method and the abnormality detection apparatus are not limited to those of the above-described embodiments, and can be changed as appropriate.
For example, in each embodiment, the vertical direction acceleration and the pitching direction acceleration are binarized, and then the abnormality is determined based on the sign mismatch rate. However, the present invention is not limited to this. For example, the phase difference is calculated using a cross spectrum. However, abnormality may be determined when the phase difference is outside the allowable range.
Also, the type and arrangement of each sensor for detecting the vertical acceleration and the pitching direction acceleration are not particularly limited.
Further, the present invention is not limited to the detection of an abnormality of the pillow spring damper provided independently of the pillow spring, but the detection of the abnormality of the pillow spring or when the pillow spring itself such as an air spring also serves as a damping element It can also be used for detection.
For example, the present invention can be used to detect a pressure drop in an air spring for a pillow spring.
In the third embodiment, the code mismatch rate or the threshold is corrected according to the traveling speed. However, when the abnormality detection is directly performed using the phase difference without using the code mismatch rate, the phase difference or this You may correct | amend the threshold value with which a phase difference is compared according to driving | running | working speed using the correlation of the phase difference in the normal time acquired beforehand, and driving | running | working speed.

DESCRIPTION OF SYMBOLS 1 Vehicle 10 Car body 20 1st bogie 21 Bogie frame 22 1st wheel shaft 23 2nd wheel shaft 24 Secondary spring system 24a Pillow spring damper 30 2nd bogie 31 Bogie frame 32 3rd wheel shaft 33 4th wheel shaft 34 Secondary spring system 34a Pillow Spring damper 100 abnormality detection device (first embodiment)
100A Abnormality Detection Device (Second Embodiment)
DESCRIPTION OF SYMBOLS 110 Processing apparatus 121 Acceleration sensor 122 Acceleration sensor 123 Acceleration sensor 130 Gyro sensor

Claims (22)

A method for detecting an abnormality of a pillow spring system provided between a body of a railway vehicle and a carriage,
Detect the vertical acceleration of the vehicle body and the acceleration in the pitching direction,
An abnormality detection method for a pillow spring system, wherein an abnormality is determined when a phase difference between the acceleration in the vertical direction and the acceleration in the pitching direction is out of a predetermined allowable range. The pillow spring system abnormality detection method according to claim 1, wherein a part of the pillow spring system in which an abnormality has occurred is specified based on a direction in which the phase difference is outside the allowable range. A component in a predetermined frequency band set in advance is extracted from the vertical acceleration and the pitching acceleration, and the phase difference between the vertical acceleration and the pitching acceleration after the extraction is out of a predetermined allowable range. The abnormality detection method for a pillow spring system according to claim 1 or 2, wherein the abnormality is determined. The abnormality detection method for a pillow spring system according to claim 3, wherein the predetermined frequency band is set so as to include a natural frequency of vibration in a vertical translation mode of a vehicle body. The pillow spring system abnormality detection method according to claim 3 or 4, wherein the predetermined frequency band is shifted to a higher frequency side in accordance with an increase in traveling speed. 6. The phase difference and at least one of the permissible range are corrected according to the traveling speed using a correlation between a normal traveling speed obtained in advance and the phase difference. The pillow spring system abnormality detection method according to any one of the preceding items. The vertical acceleration and the pitching direction acceleration after extracting the components of the predetermined frequency band are converted into codes, and the phase difference is calculated based on a mismatch rate between the vertical acceleration code and the pitching direction acceleration code. It detects. The abnormality detection method of the pillow spring system of any one of Claim 3 to 5 characterized by the above-mentioned. When the mismatch rate of the code is out of the allowable range, it is determined that there is an abnormality, and at least one of the mismatch rate and the allowable range is determined by using a correlation between a normal traveling speed and the mismatch rate obtained in advance. The pillow spring system abnormality detection method according to claim 7, wherein correction is performed according to a traveling speed. The pillow spring according to any one of claims 1 to 6, wherein the phase difference is obtained based on a cross spectrum obtained by performing a Fourier transform on a cross-correlation function between the vertical acceleration and the pitching acceleration. System abnormality detection method. The abnormality detection is performed when the traveling speed is included in a preset abnormality detection speed range, and the abnormality detection is stopped when the traveling speed is out of the abnormality detection speed range. The abnormality detection method for a pillow spring system according to any one of Items 9 to 9. A pillow spring system abnormality detection device provided between the body of a railway vehicle and a carriage,
Vehicle body behavior detection means for detecting vertical acceleration of the vehicle body and acceleration in the pitching direction;
An abnormality detection device for a pillow spring system, comprising: an abnormality detection unit that determines an abnormality when a phase difference between the vertical acceleration and the pitching direction acceleration is out of a predetermined allowable range. 12. The abnormality detection of a pillow spring system according to claim 11, wherein the abnormality detection unit identifies a part of the pillow spring system in which an abnormality has occurred based on a direction in which the phase difference is out of the allowable range. apparatus. A frequency band extracting means for extracting a predetermined frequency band component set in advance from the vertical acceleration and the pitching direction acceleration;
13. The abnormality detection unit according to claim 11 or 12, wherein the abnormality detection unit determines that an abnormality occurs when a phase difference between the vertical acceleration after the extraction and the pitching acceleration is out of a predetermined allowable range. The pillow spring system abnormality detection device described. The abnormality detection device for a pillow spring system according to claim 13, wherein the predetermined frequency band is set so as to include a natural frequency of vibration in a vertical translation mode of a vehicle body. 15. The pillow spring system abnormality detection device according to claim 13 or 14, wherein the frequency band extracting means shifts the predetermined frequency band to a higher frequency side in accordance with an increase in traveling speed. The abnormality detecting means corrects at least one of the phase difference and the allowable range according to a traveling speed by using a correlation between a normal traveling speed and the phase difference obtained in advance. The pillow spring system abnormality detection device according to any one of claims 11 to 15. Conversion means for converting the vertical direction acceleration and the pitching direction acceleration after extracting the components of the predetermined frequency band into codes;
The said abnormality detection means detects the said phase difference based on the mismatch rate of the code | symbol of the said up-down direction acceleration, and the code | symbol of the said pitching direction acceleration, The any one of Claim 13-15 characterized by the above-mentioned. The pillow spring system abnormality detection device according to claim 1. The abnormality detection means determines that an abnormality occurs when the mismatch rate of the code is out of an allowable range, and uses the correlation between the normal traveling speed obtained in advance and the mismatch rate to determine the mismatch rate and the 18. The pillow spring system abnormality detection device according to claim 17, wherein at least one of the allowable ranges is corrected in accordance with the traveling speed. The said abnormality detection means calculates | requires the said phase difference based on the cross spectrum which carried out the Fourier transform of the cross correlation function of the said vertical direction acceleration and the said pitching direction acceleration. The any one of Claim 11-16 characterized by the above-mentioned. The abnormality detection device for a pillow spring system according to the item. The abnormality detection means performs abnormality detection when the traveling speed is included in a preset abnormality detection speed range, and stops abnormality detection when the traveling speed is out of the abnormality detection speed range. The pillow spring system abnormality detection device according to any one of claims 11 to 19. The vehicle body behavior detecting means is arranged apart from the traveling direction of the vehicle, detects a vertical acceleration of the vehicle body, and detects the acceleration in the pitching direction of the vehicle body based on the outputs of the plurality of acceleration sensors. The pillow spring direction abnormality detection device according to any one of claims 11 to 20, further comprising pitching direction acceleration calculation means for calculating. The vehicle body behavior detecting means includes
An acceleration sensor for detecting vertical acceleration of the vehicle body;
The pillow spring system abnormality detection device according to any one of claims 11 to 20, further comprising an angular velocity sensor that detects an acceleration in a pitching direction of the vehicle body.

Images