JP5242538B2 - Method and apparatus for detecting step wear of pantograph sliding plate - Google Patents

Description

  The present invention relates to a method and apparatus for detecting stepped wear generated on a pantograph sliding plate.

  The pantograph sliding plate of the electric railway collects electricity while sliding with the trolley wire. The trolley wire is installed in a zigzag manner at a pitch in the left-right direction, and the sliding positions of the sliding plate and the trolley wire are dispersed in the left-right direction. In this way, local wear is prevented from occurring on the sliding plate.

  However, local wear may occur on the sliding plate due to some cause such as generation of an abnormal arc during sliding. When such wear progresses, a local recess is formed on the surface of the sliding plate. When such a concave portion exists on the surface of the sliding plate, the trolley wire is fitted, and the smooth left-right movement of the trolley wire is hindered. Furthermore, if this state continues, this recess may develop into a groove (stepped wear) that is one step lower than the other part of the sliding plate. Such stepped wear may lead to an accident such as breakage of the sliding plate or cutting of the trolley wire.

  The present invention has been made in view of the above problems, and provides a method and an apparatus for detecting step wear of a sliding plate by measuring the acceleration of a trolley wire whose behavior changes due to step wear. The purpose is to do.

  The step wear detection method of the pantograph sliding plate of the present invention is to measure acceleration in the vertical and / or horizontal direction of the trolley wire to obtain an acceleration signal, and to the acceleration signal in the vertical and / or horizontal direction of the trolley wire, It is determined that stepped wear has occurred on the sliding plate of the pantograph of the train that has passed the track under the trolley line (stepped wear occurrence) when the impulse waveform appears.

  When stepped wear occurs in the sliding plate, the trolley wire that is in sliding contact with the sliding plate is affected, and a characteristic acceleration in the vertical direction or the horizontal direction is generated in the trolley wire. Therefore, stepped wear can be detected by measuring the acceleration and obtaining the processed acceleration evaluation value.

  Specifically, stepped wear can be determined by the appearance of an impulse waveform in the vertical acceleration signal. When the trolley wire moves from the flat portion to the concave portion of the sliding plate under the situation where the stepped wear is generated on the sliding plate, an impulse-like acceleration is generated in the vertical direction on the trolley wire. Therefore, it can be determined as stepped wear by detecting the appearance of an impulse waveform in the vertical acceleration signal.

  In the present invention, it can also be determined that stepped wear has occurred when a lateral free vibration is excited in the trolley wire in the lateral acceleration signal of the trolley wire.

When the trolley wire shifts from the recessed portion of the sliding plate to the flat portion under the condition where the stepped wear of the sliding plate occurs, the trolley wire is released from the state pressed against the side wall of the recessed portion, so that the string is played. And free vibration in the left-right direction occurs. Accordingly, when it is detected in the left / right acceleration signal that the free vibration in the left / right direction is excited on the trolley line, it can be determined as stepped wear.
Specifically, the standard deviation of the acceleration signal in the left-right direction is used as an evaluation value, and when this value exceeds a predetermined threshold, it is detected that step wear has occurred.

As a more specific method of the present invention, a kurtosis (sharpness) index is obtained from acceleration signals in the vertical and / or horizontal direction of the trolley wire, and when the obtained cultosis index exceeds a predetermined threshold, step wear It can be determined that it has occurred.
Note that, in addition to kurtosis (the fourth moment of the waveform), a higher-order moment amount can be used as a method for detecting the appearance of the impulse waveform.

Furthermore, as a more specific method of the present invention, among the acceleration signals in the left-right direction of the trolley wire, a half-wavelength is provided between the curved fittings adjacent to the trolley wire, and in the left-right direction of the trolley wire. Extracts frequency signals in the frequency band including the left and right natural frequencies of the vibration mode where vibration is dominant, calculates the standard deviation of the extracted signal, and steps when the calculated standard deviation exceeds a predetermined threshold It is possible to detect the occurrence of wear.
Note that a higher-order mode than the vibration mode may be noted as the trolley wire free vibration in the horizontal direction of interest.

In the above invention, it is preferable to measure acceleration in the vertical and / or horizontal direction of the trolley line at a plurality of locations of the trolley line.
By measuring acceleration signals at a plurality of locations, stepped wear can be detected more reliably. In this case, it may be determined as abnormal when the detection result is abnormal at all measurement points, or may be determined as abnormal when the detection result is abnormal at one location. Or it can also be considered as abnormal when a specific number of sensors of a plurality of measurement points detect. These points are selected in consideration of the overhead line equipment status and pantograph usage status.

  The stepped wear detecting device for a pantograph sliding plate according to the present invention includes a sensor for measuring acceleration in the vertical and / or horizontal direction of a trolley wire, means for transmitting an acceleration signal measured by the sensor, and Means for processing / determining the transmitted acceleration signal, and determining the occurrence of stepped wear when an impulse-like waveform appears in the acceleration signal.

  According to another aspect of the present invention, a pantograph sliding plate step wear detector includes a sensor for measuring acceleration in the vertical and / or horizontal direction of a trolley wire, and a left-right vibration of the trolley wire from an acceleration signal measured by the sensor. A band-pass filter that transmits only an acceleration signal in the frequency band of the natural frequency, a means for transmitting the acceleration signal transmitted through the band-pass filter, a means for processing and determining the acceleration signal transmitted by the transmission means, It is determined that stepped wear has occurred when an impulse waveform appears in the acceleration signal.

According to the present invention, the acceleration of the left-right vibration can be efficiently detected by using the bandpass filter that transmits only the frequency of the natural frequency of the trolley line left-right vibration of interest.
In addition, when the frequency of the natural frequency of the trolley line left-right vibration of interest is lower than the lowest natural frequency of the trolley line vertical vibration, a low-pass filter can be applied instead of the bandpass filter. .

  In the above invention, if there are a plurality of sensors for measuring the acceleration, step wear can be detected more reliably.

  When stepped wear occurs on the sliding plate, the trolley wire exhibits a unique behavior when the stepped worn portion is crossed from side to side, and the acceleration in the vertical direction and the horizontal direction fluctuates. According to the present invention, since the evaluation value obtained by measuring the acceleration of the trolley wire is determined, it can be detected that step wear has occurred on the sliding plate. Thereby, generation | occurrence | production of step wear can be detected rapidly and an accident and failure can be prevented beforehand.

FIG. 1 (A) is a diagram schematically showing a stepped wear detection device according to an embodiment of the present invention, and FIG. 1 (B) is a diagram showing an example of a state in which an accelerometer is attached to a trolley wire. is there. It is a figure explaining the behavior of the trolley line in the sliding board which stepped wear generate | occur | produced, FIG. 2 (A) is the state which the trolley line moved from the flat part to the recessed part, FIG. The state which shifted to the part is shown. It is a graph which shows an example of a measurement result, FIG. 3 (A) shows the measurement result of a vertical direction acceleration, and FIG.3 (B) shows what carried out the Fourier-transform of the vertical direction acceleration for a short time. It is a top view which shows the example of arrangement | positioning of a sensor. It is a figure which shows typically the overhead wire installation used for the Example, FIG. 5 (A) is a side view, FIG.5 (B) is a top view. It is a graph which shows the measurement result of an Example. It is a figure which shows an example of the structure of a pantograph.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, the outline | summary of the installation of a trolley wire is demonstrated, referring FIG. 1, FIG.
As shown in FIG. 1A, the trolley wire 1 is supported by a hanger 3 on a suspension wire 2 suspended by a support pulley attached to a support column. Further, as shown in FIG. 4, the trolley wire 1 is supported by curved fittings (not shown) so as to be bent at a predetermined position in a plane, and zigzags meandering left and right in the rail direction as a whole. Wired to do so. Generally, the lateral displacement width W is about 400 to 500 mm, and the zigzag period is about 80 to 300 m.

The outline of the structure of the pantograph and the sliding plate will be described with reference to FIG.
The pantograph is mounted on a frame 24 installed on a roof of the train vehicle 20 via an insulator 23. The pantograph has a boat body 25 and a frame 26 that supports the boat body 25 on the base frame 23 so as to be movable up and down. The sliding plate 21 is supported by the boat body 25, and the boat body 25 is supported by a restoring spring 27 on a boat support 28 attached to the upper end of the frame 26. The sliding plate 21 is pressed against the trolley wire 1 by the elastic force of the restoring spring 27.

Next, with reference to FIG. 2, the behavior of the trolley wire when stepped wear occurs on the sliding plate will be described.
As shown in FIG. 2A, when the trolley wire 1 moves from the flat portion 21a of the sliding plate 21 to the concave portion 21b, an impact in the vertical direction is applied to the trolley wire 1, and the vertical acceleration of the trolley wire 1 and An impulse-like signal is generated in the lateral acceleration.
On the other hand, as shown in FIG. 2B, immediately after the trolley wire 1 moves from the concave portion 21b of the sliding plate 21 to the flat portion 21a, the trolley wire 1 is released from the state pressed against the side wall of the concave portion 21b. As a result, the string is played, and free vibration in the left-right direction is generated on the trolley wire 1.

  In this way, the behavior of the trolley wire is changed by the stepped wear, and the fluctuation of the acceleration inherent to the stepped wear occurs. That is, the occurrence of stepped wear can be detected by measuring the change in acceleration of the trolley wire.

An example of a stepped wear detection device will be described with reference to FIG.
In the present invention, in order to measure the acceleration of the trolley wire 1, the sensor 10 is attached to the trolley wire 1 on which the sliding plate 21 of the vehicle 20 slides. As shown in FIG. 1B, the sensor 10 includes an accelerometer 10A that measures the vertical acceleration of the trolley wire 1 and an accelerometer 10B that measures the horizontal acceleration. In general, since the direction of sensitivity of the accelerometer is determined, the same accelerometer may be arranged so that the sensitivity directions are the vertical direction and the horizontal direction, respectively. As shown in FIG. 1B, the accelerometers 10 </ b> A and 10 </ b> B can be fixed to a support member 11 attached to the trolley wire 1 via an insulating member 12.

  Each sensor 10 is connected to, for example, a measuring instrument 14 (telemeter or the like) installed on a support via a signal line 13, and a signal measured by each sensor 10 is input to the measuring instrument 14. The measuring instrument 14 is connected to a processing device 16 installed in a station or the like via a signal line 15 such as a radio wave or an optical fiber. The signal input to the measuring instrument 14 is converted into a radio wave or an optical signal and transmitted to the processing device 16 through the signal line 15.

  When the trolley wire 1 moves from the flat portion 21a of the sliding plate 21 to the concave portion 21b shown in FIG. 2 (A), the trolley wire 1 has impulse-like accelerations in the vertical and horizontal directions as described above. Occur. The acceleration signal is processed by the processing device 16 to obtain an evaluation value shown below.

(1) Kurtosis (sharpness)
The kurtosis is a scale indicating the degree of concentration of the data Xi around the average value, and is obtained by normalizing the fourth moment around the average value with the standard deviation δ. The kurtosis K is expressed by Equation 1.
Here, δ = standard deviation, N = number of data, u = average value.

The cultosis is obtained from the vertical acceleration signal of the trolley line, and it is determined that an abnormality has occurred when the cultosis exceeds a predetermined threshold. As a study example, when the sampling frequency is 2 kHz and the number of data (N) = 100, the threshold value of kurtosis is 18. In this case, if the obtained value is> 18, it is determined as abnormal. Experimental examples will be described later.
Note that the left-right acceleration of the trolley line can be evaluated in the same manner, but it is not always necessary. In this case, N and the threshold value may change.

(2) Vertical / horizontal acceleration When the vertical / horizontal acceleration of the trolley wire exceeds a threshold value, it is determined as abnormal.
A graph of a measurement example is shown in FIG. The vertical axis of the graph indicates the acceleration of the trolley line, and the horizontal axis indicates time. As shown in the graph, acceleration is suddenly generated at a certain time. When this acceleration exceeds a predetermined threshold, it is determined as abnormal.

(3) Short-time Fourier transform of vertical / horizontal acceleration Abnormal when the power of a specific frequency band exceeds a certain threshold at every time of the short-time Fourier transform result of acceleration signal in the vertical or horizontal direction of the trolley line Judge.
FIG. 3B shows a measurement example graph. The vertical axis of the graph represents frequency, and the horizontal axis represents time. The blue color means less power and the red color means more power. When the power in the frequency band (200 Hz to 950 Hz) enclosed by the square in the figure exceeds a certain threshold, it is determined as abnormal. In this example, as shown in the figure, a portion displayed in red is included in a region surrounded by a square.

  Next, the case where the trolley wire 1 shown in FIG. 2 (B) has moved from the concave portion 21b of the sliding plate 21 to the flat portion 21a will be described. In this case, the trolley wire vibrates freely in the left-right direction as described above. The acceleration signal at this time is processed to obtain an evaluation value shown below.

(1) Standard deviation of acceleration signal in the left-right direction The natural frequency in the left-right direction and the up-down direction of the trolley wire is determined by various constants of the trolley wire (line density, tension, tension structure, hanger interval, support point interval, etc.). Using a bandpass filter that transmits only the frequency of the natural frequency of the vibration mode in which the left-right acceleration signal has a half-wavelength between adjacent curved fittings of the trolley wire and the left-right vibration of the trolley wire is dominant Thus, the acceleration in the frequency band of the natural frequency of the left-right vibration is detected. The standard deviation δ of the acceleration signal Xi is obtained by the following formula, and when the obtained value exceeds the threshold value, it is determined as abnormal.
Here, N = number of data and u = average value.
In the above example, attention is paid to a vibration mode having a half wavelength between adjacent curved fittings. However, a vibration mode having a half wavelength between adjacent support points or hangers may be noted. As a study example, when the sampling frequency is 2 kHz and the number of data (N) = 800, the threshold value of the standard deviation of the lateral acceleration is 0.5. In this case, if the obtained value is> 18, it is determined as abnormal. Experimental examples will be described later.

An example of a bandpass filter is shown.
Although the natural frequency of the trolley wire in the vertical direction and the horizontal direction varies depending on the conditions, in the present examination example, the natural frequency of the vertical acceleration is 3.9 Hz, 9.8 Hz, 11.7 Hz,. The natural frequencies of the lateral acceleration were 5.4 Hz, 7.3 Hz, 10.3 Hx,. From this result, a bandpass filter having a passband of 5.0 Hz to 8.0 Hz can be applied. By using such a bandpass filter, free vibration in the left-right direction can be detected efficiently.
Note that when the frequency of the trolley line left-right vibration of interest is lower than the natural frequency of the lowest-order vibration mode of the trolley line vertical vibration, a low-pass filter can be applied instead of the band-pass filter.
There is also a method of shifting the natural frequency of the trolley wire up and down and left and right by increasing the number of hangers or widening the installation interval of the curved drawing metal fittings.

  The measurement points for measuring the acceleration for obtaining the evaluation value described above can be provided at one place or a plurality of places within a predetermined measurement area. When multiple measurement points are provided, it may be determined as abnormal when the detection results are abnormal at all measurement points, or may be determined as abnormal when the detection result is abnormal at one location. Good. When evaluating from all detection results, there is a high probability that stepped wear cannot be detected and missed, and when evaluating from a single detection result, the probability of falsely detecting a normal sliding plate as stepped wear Becomes higher. Or it can also be considered as abnormal when a specific number of sensors of a plurality of measurement points detect. These points are selected in consideration of the overhead line equipment status and pantograph usage status.

  When determining from all the measurement results of a plurality of measurement points, the timing at which the wave of the trolley line enters the accelerometer is not dependent on the measurement points at the same time. Different. For this reason, it is necessary to allow a deviation in detection timing on the time axis within a time range obtained by dividing the interval between measurement points by the propagation speed of the wave of the trolley line.

An example in the case of providing a plurality of measurement points is shown in FIG. FIG. 4 is a plan view schematically showing the installation state of the trolley wire. As described above, the trolley wire 1 is supported by the hanger 3 on the suspension wire (not shown in FIG. 4) suspended by the support pulley attached to the support column 5, and in a predetermined position on the plane. It is supported to be bent at.
When providing a plurality of measurement points, a plurality of accelerometers 10 may be installed in a section between adjacent columns 5 as shown in FIG. 4 (A). As shown in FIG. A plurality of accelerometers 10 may be installed across a plurality of sections sandwiching. However, in any case, since the trolley wire 1 is bent at a predetermined position and arranged in a zigzag manner as described above, it is distributed in the effective displacement width W of the sliding plate in the rail direction.

A processing example of the measurement result of the accelerometer will be described.
FIG. 4A shows an example in which a measuring instrument 14 is installed on the column 5 as in FIG.
Alternatively, as shown in FIG. 4B, the sensor 10 may be provided with a signal processing function, and the signal may be transmitted to the processing device 16 through the sensor network 17 or the like.

Experiments were performed using the overhead wire facility shown in FIG.
The support pillars 5 were erected at a predetermined interval, and the suspension wire 2 was bridged between the support pillars 5. An auxiliary suspension line 9 is stretched over the suspension line 2 by a plurality of droppers 8. The trolley wire 1 is supported by the hanger 3 on the auxiliary suspension wire 9. As shown in FIG. 5B, the trolley wire 1 is supported so as to be refracted at a certain position in plan view.

  In this example, five measurement points P1 to P5 are provided in the section between the hangers in FIG. 5, and two accelerometers 10 are attached to each measurement point, as shown in FIG. 1B. . The accelerometer at each measurement point is attached so as to measure the vertical acceleration and the horizontal acceleration of the trolley line.

  A vehicle 20 equipped with a sliding plate 21 on which stepped wear was intentionally formed was run on such an overhead wire facility, and the vertical and horizontal accelerations at each measurement point P1 to P5 were measured.

FIG. 6 is a graph showing the measurement results.
The part shown in the upper part of the graph shows the measurement results of the vertical acceleration and the horizontal acceleration at each measurement point. The vertical axis of the graph represents acceleration, and the horizontal axis represents time. The red line indicates the horizontal direction, and the black line indicates the vertical direction. Similar measurement results were obtained at each measurement point.

The part shown in the center of the graph shows the result of obtaining kurtosis at each measurement point from the obtained vertical acceleration signal. The vertical axis of the graph represents kurtosis and the horizontal axis represents time.
From the graph, the kurtosis is prominent in the portion where the acceleration signal is in the form of an impulse, and the other portions are almost unchanged. Thereby, it can be determined that the trolley wire has shifted from the flat portion to the concave portion at the protruding portion.

The part shown in the lower part of the graph shows the result of obtaining the standard deviation from the lateral acceleration signal at each measurement point. The vertical axis of the graph represents standard deviation, and the horizontal axis represents time.
As can be seen from the graph, the standard deviation increases slightly before the time from 9.418 seconds. As a result, it can be determined that the trolley wire has shifted from the concave portion to the flat portion at this portion.

From these results, it can be determined from the cultosis of the vertical acceleration signal of the trolley wire that the trolley wire has moved from the flat part to the concave part, and the trolley line has moved from the concave part to the flat part from the standard deviation of the lateral acceleration signal of the trolley line. It was found that it was possible to judge. That is, it is possible to detect the occurrence of stepped wear on the sliding plate based on the kurtosis and the standard deviation. When step wear is present, the trolley wire behaves such that it moves from the flat part to the concave part and from the concave part to the flat part. That means
(1) When shifting from a flat part to a concave part and moving from a concave part to a flat part,
(2) When shifting from a flat part to a concave part,
(3) When transitioning from a concave portion to a flat portion,
In either case, it indicates that step wear has occurred. Which case is applied is determined in consideration of the condition of the overhead line equipment and the measurement condition.

DESCRIPTION OF SYMBOLS 1 Trolley line 2 Suspension line 3 Hanger 8 Dropper 9 Auxiliary suspension line 10 Sensor 11 Support member 12 Insulation member 13 Signal line 14 Measuring instrument 15 Signal line (radio, optical fiber, etc.)
DESCRIPTION OF SYMBOLS 16 Processing apparatus 17 Sensor network 20 Vehicle 21 Sliding board 23 Insulator 24 Platform 25 Ship body 26 Frame 27 Restoration spring 28 Boat support

Claims (8)

Measure acceleration in the vertical and / or horizontal direction of the trolley wire to obtain an acceleration signal,
Stepped wear has occurred on the pantograph sliding plate of the train that has passed the track under the trolley line due to the appearance of an impulse waveform in the acceleration signal in the vertical and / or horizontal direction of the trolley line (stepped) A stepped wear detection method for a pantograph sliding plate, characterized in that it is determined that there is a wear on the pantograph).   2. The pantograph according to claim 1, wherein stepped wear is determined to occur when a free vibration in the left-right direction is excited on the trolley line in the left-right acceleration signal of the trolley line. A method for detecting stepped wear on sliding plates. A kurtosis (sharpness) index is obtained from acceleration signals in the vertical and / or horizontal directions of the trolley line,
2. The method for detecting step wear of a pantograph sliding plate according to claim 1, wherein stepped wear is determined to occur when the obtained kurtosis index exceeds a predetermined threshold. Among the acceleration signals in the left-right direction of the trolley wire, the left-right natural frequency of the vibration mode in which the left-right vibration of the trolley wire has a half wavelength between adjacent curving fittings of the trolley wire and includes the left-right vibration is included. Extract frequency signals in the frequency band,
Find the standard deviation of the extracted signal,
2. The step wear detection method for a pantograph sliding plate according to claim 1, wherein the occurrence of step wear is detected when the obtained standard deviation exceeds a predetermined threshold value.   The stepped wear detection method for a pantograph sliding plate according to any one of claims 1 to 4, wherein acceleration in the vertical and / or horizontal direction of the trolley wire is measured at a plurality of locations of the trolley wire. . A sensor for measuring acceleration in the vertical and / or horizontal direction of the trolley wire;
Means for transmitting an acceleration signal measured by the sensor;
Means for processing and determining an acceleration signal transmitted by the transmission means;
With
A stepped wear detecting device for a pantograph sliding plate, wherein the stepped wear is determined to be generated when an impulse waveform appears in the acceleration signal. A sensor for measuring acceleration in the vertical and / or horizontal direction of the trolley wire;
A bandpass filter that transmits only the acceleration signal in the frequency band of the natural frequency of the left-right vibration of the trolley wire from the acceleration signal measured by the sensor;
Means for transmitting an acceleration signal transmitted through the band-pass filter;
Means for processing and determining an acceleration signal transmitted by the transmission means;
A stepped wear detecting device for a pantograph sliding plate, wherein the stepped wear is determined to be generated when an impulse waveform appears in the acceleration signal.   The stepped wear detecting device for a pantograph sliding plate according to claim 6 or 7, wherein there are a plurality of sensors for measuring the acceleration.