EP3487747B1 - Method and device for detecting roll motion of a rail vehicle car body relative to the bogie - Google Patents

Description

Technical field

The invention relates to a method and a device for detecting a roll movement of a rail vehicle body relative to the chassis.

State of the art

Rail vehicles can be excited to vibrate about their longitudinal axis. The chassis springs on the right and left side of the car alternately spring in, which leads to corresponding roll movements of the car body. This movement can be perceived as uncomfortable by passengers and, in extreme cases, can also be safety-relevant. According to the prior art, dampers are used in parallel with the chassis springs to reduce the rolling movement, which convert the kinetic energy of the car body into heat. The rolling motion is generally excited by the course of the route as a function of the driving speed, for example by driving through switch routes at a speed which is suitable for exciting the rolling natural frequency of the vehicle. A roll movement triggered in this way is not critical and subsides quickly. However, there is another way to deliberately induce this roll motion by coordinating misconduct by passengers. For example, a group of passengers can pass through rocking together on handrails cause this roll. A roll motion triggered in this way does not subside quickly and persists as long as the excitation is given. It is possible to hit the roll natural frequency exactly and over a longer period of time, which can lead to considerable roll angles of the car body. Such a rolling movement is not immediately apparent to the vehicle driver, only when the locomotive is affected can this state be recognized and reacted to. In driverless vehicles, such as modern subways, there is no way to detect this condition.

Methods for detecting a risk of derailment are known from the prior art, for example in the patent application EP 3 006 301 A1 disclosed such a system. The angular velocity of the rolling motion of a car body is determined and a predictive value is generated from this, from which a risk of derailment is concluded.

Presentation of the invention

The invention is therefore based on the object of specifying a method and a device for detecting a roll movement of a rail vehicle body relative to the chassis, which can reliably detect permanent roll movements (vibrations about the longitudinal axis) and distinguish them from transient roll movements.

The object is achieved by a method having the features of claim 1 and a device according to claim 6. Advantageous refinements are the subject of subordinate claims.

• Ermitteln eines der momentanen Verdrehung des Wagenkastens um die Längsachse des Schienenfahrzeugs proportionalen Signals,
• Zuführen dieses Signals an einen Bandpaßfilter,
• Vergleich des im vorherigen Schritt gefilterten Signals mit einem Grenzwert,
• Auslösen eines Beobachtungszeitraums mit bestimmter Länge wenn das gefilterte Signal den Grenzwert überschreitet,
• Zählung der Anzahl der Grenzwertüberschreitungen des gefilterten Signals innerhalb des Beobachtungszeitraums,
• Erkennung einer Wankbewegung wenn innerhalb eines Beobachtungszeitraums mehrmals Grenzwertüberschreitungen des gefilterten Signals gezählt wurden,
• Ausgeben eines die Wankbewegung anzeigenden Signals.

According to the basic idea of the invention, a method for detecting a roll movement of a rail vehicle body relative to the chassis (2) is described with the following method steps:

• Determining a signal proportional to the momentary rotation of the car body about the longitudinal axis of the rail vehicle,
• Feeding this signal to a bandpass filter,
• Comparison of the signal filtered in the previous step with a limit value,
• Triggering an observation period of a certain length if the filtered signal exceeds the limit value,
• Counting the number of limit violations of the filtered signal within the observation period,
• Detection of a roll movement if limit violations of the filtered signal were counted several times within an observation period,
• Output a signal indicating the roll motion.

This has the advantage of being able to detect permanent roll movements and to be able to issue an alarm. In particular, a distinction between short-term (transient) wavering and intentionally induced wavering can be distinguished.

The method according to the invention uses a signal which is proportional to the momentary rotation of the car body about the longitudinal axis of the rail vehicle in relation to the chassis. Such a signal can be obtained, for example, by means of an inclination angle sensor which directly determines the roll angle between the car body and a chassis. Another possibility is to provide a rotation rate sensor on the car body and its After integration in time, use the output signal as the signal indicating the roll angle.
A particularly advantageous embodiment of the invention provides for the pressure differences in the air bellows to be used as a measure of the roll angle.

This signal, which describes the roll angle, is to be subjected to bandpass filtering in a first step in order to filter out irrelevant frequencies in the signal. The center of the pass band of the bandpass filter is essentially to be designed for the natural roll frequency of the spring-mass system consisting of the body and air springs. This natural roll frequency depends on the loading of the rail vehicle, since the static gas pressure in the air springs is usually designed to be variable for level control and a change in pressure causes a change in the spring constant. A roll natural frequency of a common rail vehicle is typically 0.5 Hz. The center frequency of the pass band of the band filter can be readjusted as a function of the static gas pressure in the air springs in order to ensure that there is an exact roll detection in all loading conditions and that false warnings are avoided.

The most common design of modern rail vehicles provides two bogies with two axles per wagon, with a left and a right air spring arranged on each bogie. If the pressure differences in the air bellows are used as a measure of the roll angle, it is advantageous to add up the respective pressure differences at the individual bogies (the air bellows of a bogie). Such can be out of phase Rolling movements do not trigger roll detection.

Following band filtering, the band-filtered signal is formed in an amount and this amount signal is compared with a predetermined limit value. This limit value is proportional to the roll angle from which a roll warning is to be given. However, a warning should not be given if this roll angle is transiently exceeded once, but only as soon as a constant, no longer decaying vibration has been determined. For this purpose, if the angle at which a warning is to be issued is exceeded, a timing element is triggered over a specific observation period and the number of exceedances in this observation period is counted. If this number exceeds the value 3, then this indicates with a very high probability that the body of the vehicle is no longer vibrating or is decaying too slowly, and a warning signal is being issued.

This warning signal can advantageously be brought to the view of the vehicle driver. It is particularly advantageous to supply this warning signal to a vehicle control system, which then limits the maximum driving speed. In the case of driverlessly operated vehicles, a transmission of this warning signal to a stationary device is also advantageous, so that the driving operation can be controlled accordingly.

The method according to the invention is advantageously carried out by means of a roll detection device which comprises a control device in which the processing steps are carried out. This The control device is to supply the signal proportional to the momentary rotation of the car body about the longitudinal axis of the rail vehicle relative to the chassis. A bandpass filter is to be arranged in the control unit, which bandpass filters the supplied signal. The center frequency of the pass band of the bandpass filter is essentially to be matched to the roll natural frequency of the rail vehicle. Furthermore, the control device comprises an amount formation unit for forming the amount of the filtered signal. Furthermore, a comparison device for comparing the amount of the signal with a specific limit value is to be provided, wherein if the limit value is exceeded, a timing element is to be triggered, which causes the limit value violations to be counted for a specific observation period. The observation period is typically to be set to a length of more than three oscillation periods of the roll natural frequency. For example, the observation period can be set to a value of 6 to 7 seconds at a roll natural frequency of 0.5 Hz. This ensures that repeated limit violations can be detected in one observation period. In practical applications, three successive limit violations are a sure indication that there is constant vibration of the body around the longitudinal axis, which is not stimulated by the driving operation, but whose cause is the coordinated misconduct of several passengers and is therefore deliberately caused, or a damage on a chassis that does not provide adequate roll damping.
The specific number of limit violations, which should lead to a warning, is to be measured for the respective specific application. In any case, it is only a small number of limit violations are required, so that a very early warning can be given before potentially dangerous operating states occur.
If an observation period expires in which fewer limit violations could be counted, no warning is issued and the process begins again.
If a sufficient number of exceedances is determined, the control device transmits a warning signal which informs the driver of this unusual condition in a train car. In particular, it is advantageous to also automatically limit the maximum driving speed.
Furthermore, it can be advantageous to provide for the transmission of this warning message to a stationary device, which is particularly important in the case of driverless vehicles.

Brief description of the drawings

Fig.1

Flußdiagramm eines Verfahrens zur Wankerkennung.

Fig.2

Schienenfahrzeug, Schnittdarstellung.

Fig.3

Einrichtung zur Wankerkennung.

The following are examples:

Fig. 1

Flow diagram of a method for roll detection.

Fig. 2

Rail vehicle, sectional view.

Fig. 3

Roll detection device.

Implementation of the invention

Fig. 1 shows an example and schematically a flow diagram of a method for roll detection. The process flow set out in the flowchart sees the supply of a Wanksignal S on band filter before. The amount of the output signal S _{filter is} determined in a further sequence. The magnitude signal of the bandpass filter is subjected to a comparison with a limit value S _lim . A decision is made according to the relationship | S _filter |> = S _lim , whereby if the relationship | S _filter | is not _fulfilled > = S _lim no wavering is recognized and the process starts again from the first processing step. If the relationship is | S _filter | > = S _{lim is} fulfilled, ie the magnitude signal is greater than the limit value, the observation period T begins with a certain length. At the same time, the number of overshoots in the observation period T is counted, the first overshoot that triggers the expiration of the observation period T being counted. The exemplary embodiment shown has a number of required exceedances of three. If three exceedances are detected in the observation period T , a waver is recognized and a warning signal 10 is output. If fewer than three exceedances are counted in the observation period T , no wavering is recognized and the method continues with the first processing step.

Fig. 2 shows an example and schematically a sectional view through a rail vehicle. A section through a rail vehicle 3 is shown transversely to the longitudinal direction in the area of a chassis 2. A left 4 and a right 5 air spring are arranged between the chassis 2 and the car body 1. Other components, such as roll dampers, are in Fig. 2 not shown. The car body is also shown in a further position 1'd, in which it is in a strong roll located. In the position 1 'shown, the gas pressure in the left air spring 4 is increased compared to the gas pressure in the right air spring 5 due to the roll movement. This pressure difference can be used in the objective process for roll detection. A connection of the gas spaces of the air springs 4, 5 is customarily provided, but an overflow occurs at a pressure difference much more slowly than the pressure modulation due to the roll.

Fig. 3 shows an example of a device for roll detection. The device comprises control device 11, a left-hand pressure measuring device 6 for determining the gas pressure in a left air spring 4 and a right-hand pressure measuring device 7 for determining the gas pressure in a right-hand air spring 5. The signals p 1 and 4 in the pressure measuring devices 6, 7 transmit the measured gas pressures p 1 to a differential image 8 in the control device 11. The differential pressure signal .DELTA.p determined by the differential image 8 is forwarded to a logic 9 which executes the further method sections as described in the description Fig. 1 are listed. The logic 9 is set up to output a warning signal 10.

List of names

1

Rail vehicle car body

2nd

chassis

3rd

Rail vehicle

4th

Air spring on the left

5

Right air spring

6

Pressure measuring device on the left

7

Pressure measuring device on the right

8th

Difference pictures

9

logic

10th

Warning signal

11

Control device

S

Roll signal

S _filter

Bandpass filtered roll signal

S _lim

limit

T

Observation period

p 1

Left air spring gas pressure

p 2

Right air spring gas pressure

Δp

Differential pressure

Claims (11)

1. Method for detecting a roll movement of a rail vehicle body (1) in relation to the running gear (2), with the following method steps:

   - ascertaining a signal (S) proportional to the instantaneous torsion of the vehicle body about the longitudinal axis of the rail vehicle (3),

   - feeding this signal (S) to a band-pass filter,

   - summating the signal (S_filter) filtered in the previous step and comparing the magnitude of the signal (S_filter) with a limit value (S_lim),

   - triggering an observation time period (T) with a particular length, when the magnitude of the filtered signal (S_filter) exceeds the limit value (S_lim),

   - counting the number of limit value exceedances of the filtered signal (S_lim) within the observation time period (T),

   - detecting a roll movement, if limit value exceedances of the filtered signal (S_filter) have been counted multiple times within an observation time period (T),

   - outputting a signal (10) indicating the roll movement.
2. Method for detecting a roll movement according to claim 1,
   characterised in that the signal (10) indicating the roll movement causes a limitation of the maximum travel speed of the rail vehicle (3).
3. Method for detecting a roll movement according to one of claims 1 or 2,
   characterised in that the signal (10) indicating the roll movement is used in order to warn a vehicle driver.
4. Method for detecting a roll movement according to one of claims 1 to 2,
   characterised in that the signal (10) indicating the roll movement is transferred to a fixed-location facility.
5. Method for detecting a roll movement according to one of claims 1 to 4,
   characterised in that a detection of a roll movement takes place when three limit value exceedances of the filtered signal (S_filter) have been counted within an observation time period (T).
6. Facility for detecting a roll movement of a rail vehicle body (1) in relation to the running gear (2),
   characterised in that
   a control facility (11) and a facility for ascertaining the instantaneous torsion of the vehicle body (1) about the longitudinal axis of the rail vehicle (2) relative to the running gear (2) are provided, wherein the facility for ascertaining the instantaneous torsion of the vehicle body (1) about the longitudinal axis of the rail vehicle (2) relative to the running gear (2) transmits a signal (S) proportional to the torsion to the control facility (11), wherein the control facility (11) comprises a band-pass filter for filtering the signals (S), and a comparison unit for comparing the magnitude of the output signal (S_filter) of the band-pass filter to a limit value (S_lim), wherein, when the limit value (S_lim) is exceeded, a timer for an observation time period (T) with a particular length is triggered, and wherein a counting facility ascertains the number of exceedances of the limit value (S_lim) within the observation time period (T), and wherein the control facility (11) outputs a signal (10) indicating the roll movement, when exceedances have taken place multiple times within an observation time period (T).
7. Facility for detecting a roll movement of a rail vehicle body (1) in relation to the running gear (2) according to claim 6,
   characterised in that the facility for detecting the instantaneous torsion of the vehicle body about the longitudinal axis of the rail vehicle relative to the running gear comprises two pressure gauge facilities (6, 7), which are each configured to ascertain the gas pressure in each pneumatic spring (4, 5) of a bogie and wherein a signal (Δp) proportional to the difference between said gas pressures is transmitted to the control facility (11) as a signal proportional to the torsion.
8. Facility for detecting a roll movement of a rail vehicle body (1) in relation to the running gear (2) according to one of claims 6 or 7,
   characterised in that the control facility (11) outputs a signal (10) indicating the roll movement when three exceedances of the limit value (S_lim) have taken place within an observation time period (T).
9. Facility for detecting a roll movement of a rail vehicle body (1) in relation to the running gear (2) according to claim 6,
   characterised in that the facility for ascertaining the instantaneous torsion of the vehicle body (1) about the longitudinal axis of the rail vehicle (3) relative to the running gear (2) comprises an incline angle sensor.
10. Facility for detecting a roll movement of a rail vehicle body (1) in relation to the running gear (2) according to claim 6,
    characterised in that the facility for ascertaining the instantaneous torsion of the vehicle body (1) about the longitudinal axis of the rail vehicle (3) relative to the running gear (2) comprises a rotation rate sensor.
11. Rail vehicle, comprising a facility for detecting a roll movement according to one of claims 6 to 10.

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