EP0689983B1 - Method for detecting the position of a predetermined axle of a railway vehicle on a rail section - Google Patents

Abstract

A method for ascertaining the position (POS) of an assigned axle (A4) of rail-borne vehicle (F) on a railway section (GA) involves obtaining a position signal for the axle on the railway section (GA) in order to derive a position result from the position signal by assigning reference values. In order to provide an exact location of the axle and rail-borne vehicle on a limited section of railway, an annunciation signal (Ut) is generated when the axle (A4) passes a defined fixed point on the railway section (GA), followed by checking for any deviation of the obtained position signal (fs) for this point.

Description

The invention relates to a method for determining the position a specific axis of a rail vehicle on a Track section in which one of the position of the axis in the Track section dependent position signal is obtained from a position information by assigning reference values is derived.

EP-B1-0 272 343 describes a method and a device to monitor the presence of rail vehicles known within a track section, the track section divided into many comparatively short subsections at the end of each one a transceiver module is arranged. One as a digital track level meter trained receiving device at the beginning of the track section Cyclically checks which modules have been requested a response signal can be detected at all. The known methods thus only allow digital (free / occupied) Checking the subsections. The position of a Axis of a vehicle is within the subsection therefore not more finely resolvable. For a sufficient resolution To achieve is a very fine division and therefore one high number of transmitter / receiver modules required.

German patent 967 440 relates to a device for Display of the filling status of a track, whereby the track is a Forms conductor loop, the electrical resistance of which short-circuit-generating position of the last in the direction of entry Vehicle axis is determined. After that Additional patent 11 19 901 is already on a free track by the conductance of the track bedding or a permanent one conductive connection occurring between the rails Deflection of a level indicator by a Counter voltage compensated.

EP-A2-0 539 046 describes a track section which is used for Position detection of a vehicle at both ends with one Transmitter and a receiver for bidirectional signal transmission is equipped over the tracks. The capture a vehicle position is also done here by a Current or voltage measurement.

The essay "THE INSULATION-FREE TONE FREQUENCY TRACK CIRCUIT OF THE TYPE WSSB "by V. Bechstein in DEUTSCHE EISENBAHNTECHNIK, Jg. 13, 2/1965, pages 83 ff. Describes a track section with a Receiver, which from the short-circuit effect in an insulated without Track circuit incoming axis a busy message generated.

DE-C2-31 27 672 describes a method of the type mentioned Kind known, the track section by separating joints opposite other adjacent track sections The entire track is insulated and designed as a track circuit is. An oscillator is connected to the track circuit, whose quiescent frequency depending on the inductance of the Track circuit - which in turn is related to the position of the Axis changes - varies. The frequency determined thus represents a location-dependent position signal that when entering or an axis runs into or out of the track section striking frequency jumps. The position signal will forwarded to a converter designed as a memory, the one for each possible frequency by experiments or calculated value for the free length of the associated track circuit or track section. By assigning the corresponding value to the determined Position signal a position indication is obtained, which in functional connection with the location of the respective axis stands.

In this known method, determined for the same location Position signals z. B. due to external influences (Weather; insulation resistance between the rails; track structure) drift so that after assigning the previously determined Reference values increasingly imprecise position information surrender.

The invention is therefore based on the object of a method to determine the position of a specific axis Rail vehicle on a limited section of track create that even with longer operating times and with external Interference influences an exact location of the axis and thus the Rail vehicle enables.

This task is carried out in a method of the type mentioned at the beginning Art solved according to the invention in that regardless of the position signal obtained, generates a message signal when the axis has a defined fixed point of the track section happens that it is checked whether a Deviation of the position signal obtained for this point or the derived position specification from one for this Point applicable setpoint is present and that a tracking of all position signals reducing the deviation or a correction of the assignment of the reference values to the position signals. An essential one Aspect of the invention is that in addition to Comparison of the functional relationship between the position reference values that can be used for the axis and the position signal for the boundaries of the track section (first and second support point) with the signal a third, of which Position signal independent reference point as setpoint for Assessment and if necessary to compare the functional Context or to correct the assignment stands. Each time the defined fixed point is passed advantageously delivers a current, reliable Setpoint for the position signal or position specification, see above that two determined by essentially independent methods Comparable information is available. The position signal for this point can either be a separate measured value or by a suitable interpolation of the position signals be won in the area of the fixed point.

The method according to the invention generates at the start of operation not just digital information (free / occupied) for the Track section, but already allowed via the position signal an estimate of the axis position. An essential one Increase or check the accuracy of the position signal can be relatively quickly during normal operation of the track section. This is especially so advantageous if, for example, due to longer breaks the determined position signals and thus the obtained Position information from the actual position of the fixed Point according to the corresponding target values. The functional relationship can be corrected with known mathematical methods (for example regression analyzes) respectively; from the observed deviation can correct the position signals by interpolation or assignment through adaptive control or tracking respectively.

A particularly advantageous embodiment of the invention provides before that the fixed point in the middle area of the track section is provided.

The influence of particularly high deviations (statistical To limit outliers) sees a further preferred embodiment the invention that the tracking is only made if there are multiple significant deviations in the same direction be determined from the setpoint.

According to an advantageous development of the invention, the Signal signal generated by a wheel sensor. The message signal can also be generated by a switch that When passing the axis, the rails short-circuited and thus a significant jump in the position signal curve (for example a frequency jump at the beginning described inductive method) causes.

In multi-axle vehicles in particular, it is advantageous when determining the time at which the last axis of the vehicle passes the fixed point, so that the position signal and evaluated the signal for the last axis can be.

For this purpose and with regard to simplified data processing can at least the last two position signals saved at the time of the last two message signals stay.

Another advantageous embodiment of the invention The method provides that the deviation of the position signal or the position specification of the setpoint in the vicinity of the fixed point with the help of a suitable Smoothing function is determined. For example a regression line can be used; to form the Regression lines can each have a predetermined number of Position signals or information continuously for a certain period of time (e.g. 20 s) can be saved. In Knowledge of the time of the signal can then be through Averaging of random interference or Noise-free value for the position signal or the Position information can be determined from which the Deviation is determined.

Figur 1 eine schematische Darstellung der Positionsermittlung einer Achse auf einem Gleisabschnitt,

Figur 2 in Abhängigkeit von der Achsposition ermittelte Positionssignale und

Figur 3 eine markante Sprünge aufweisende Frequenzkurve.

The invention is explained further below by way of example with reference to a drawing; show it:

FIG. 1 shows a schematic representation of the position determination of an axis on a track section,

Figure 2 as a function of the axis position and position signals

FIG. 3 shows a frequency curve with striking jumps.

mit n > 1 gegeben ist.According to FIG. 1, in the method according to the invention for determining the position POS of a specific axis A4 of a rail vehicle F (not shown in more detail), a limited track section GA is integrated into the resonant circuit of an oscillator OS in a manner known per se (DE-C2-31 27 672). The oscillator OS is electrically isolated from the track section GA via a transformer TR. The track section GA is electrically insulated from adjacent track sections by dividing joints T1, T2. The axes A1 to A4 of the vehicle F short-circuit the two rails S1, S2 of the track section GA - as a result of which the track circuit inductance changes as a function of the axis position - and thus influence the oscillation frequency f (s) of the oscillator OS. Since the oscillator OS is coupled (seen in the direction of travel R) to the start region of the track section, the position of the last axis A4 is essentially decisive for the change in impedance of the track section and thus for the change in the oscillator frequency. The frequency determined as the position signal f (s) is a function of the path s between the start A of the track section GA and the axis position POS, with a basic relationship of the shape

with n> 1.

Accordingly, the position signal f (s) can be calculated or assignment of previously stored reference values (as described at the beginning) a position specification PA (s) for the Determine the location of the A4 axis. When rolling in the vehicle F in the track section GA the frequency jumps from a rest value of for example 4 kHz (Figure 2) to a value of z. B. 10 kHz and continues to move along axis A4 of the path S hyperbolic to an end value from, for example, 7 kHz. If the axis A4 the track section GA leaves (open track circuit), jumps Frequency f back to the idle value.

Due to external changes (e.g. changing the Bedding resistance, electrolyte formation due to lost cargo) the track section specific inductance can the position signal f (s) obtained from that originally for the position signal (setpoint) determined at the respective location differ.

The frequencies actually measured then do not correspond more the one originally determined for the respective positions Frequency values as shown in the solid curve K1 shown in Figure 2. Rather, the position signal the frequency response of the dashed curve K2 or correspond to the dash-dotted curve K3, the curves K1 to K3 in their initial and final values and also in their Curvatures can differ from each other.

As FIG. 1 further shows, a wheel sensor RS is arranged at a defined, fixed point P of the track section GA, which then generates a signal U (t) when the point P is passed by an axis A1 to A4. As shown in FIG. 2, Dirac impulse-like alarm signals U1 to U4 are generated at defined times t ₁ to t ₄ , each of which indicates the passage of point P from one of the axes A1 to A4. Positions s ₁ to s _{4 can be} assigned to times t ₁ to t ₄ (linearly at constant speed, otherwise by evaluating the speed curve). Depending on the desired representation, the time t or the location s is therefore plotted on the abscissa. At each of the times t1 to t4, preferably at least at the respective last times t3, t4, the position signals f (s, t ₃ ) obtained at this time are; f (s, t ₄ ) stored in a memory SP. If after the last signal U 4th = U (t 4th ) _ver during a time T confidence - at the latest after leaving the track section - received no further message signal can be assumed that the last axis has passed the point A4 P with reasonable assurance. For this purpose, the method according to the invention can use an observation window of length s _er , since the position of point P is known in advance and thus the curve section in which position signals assigned to point P are to be expected can also be predetermined.

The position signal f (s, t ₄ ) obtained and stored at the point in time t ₄ can now be assigned to the ideal or target curve K1 for the frequency f (s _p ) at the point P (intersection point SP1) with the target value of the ideal or target curve K1 determined with the aid of the message signal ) are compared. The signal U ₄ allows namely to check whether the assigned position signal f (t ₄ ) actually lies on the target curve K1 previously used for determining the position or on a deviating curve K3 (intersection point SP2). If the position signal f (t ₄ ) lies outside a predeterminable tolerance band TB, interpolative methods may be used with the aid of the frequency values that are used for the start A (f (s = 0)) and for the end E ( f (s = s Max ) ) of the track section were obtained, for all frequency values f (s), a tracking (in the present example, raising) and, if necessary, correction of the curvature, so that the frequency curve K1 is approximately reached and the original functional relationship is thus restored. Alternatively, the adjustment can also be carried out by adapting the assignment of the reference values to the position signals accordingly.

In order to eliminate extreme values (outliers) of the position signal, the described correction is preferred then made if several times in succession Deviations of the position signals from the setpoint in the same direction be determined.

FIG. 3 shows another transmission and generation option for the signal signals M1 to M4, in that when the point P (FIG. 1) passes the axes A1 to A4, a defined short circuit is generated between the rails S1, S2. This short circuit leads to striking jumps (signal signals M (t)) in the frequency curve shown in FIG. 3. On the basis of these jumps, the times t ₁ to t ₄ can be determined in a corresponding manner for the purposes described above. An advantage of this embodiment is that the signal signals M ₁ to M ₄ superimposed on the position signal can be passed over the rails S1 and S2.

Basically, it can also be used to generate the position signal for example from DE-PS 967 440 or DE-PS 11 19 901 known resistance measurement of the track section applied will.

With the method according to the invention, two different Measurement methods or media two support points for the Start and end of the track section and one preferably others assigned to the central area of the track section independent support point generated. That is an extreme exact adjustment of the curve or the assignment of the Reference values for the position signals possible, so that a extremely precise location of an axle of a rail vehicle is possible. The method according to the invention is in particular Can be used advantageously for locating in directional tracks. By the message signals delivered during normal operation can adaptive control or tracking to the actual Realize conditions without business interruption. The achievable with the method according to the invention very precise and stable location over time allowed by differentiation also a determination of the Running speed and thus a determination of the running speed or a prognosis of the running distance up to to a standstill of the vehicle. This is the inventive Process, in particular for braking the destination on directional tracks Can be used advantageously at marshalling yards.

Claims (8)

1. Method for determining the position (POS) of a specific axle (A4) of a rail vehicle (F) on a track section (GA), in which a position signal (f(s)) dependent on the position (POS) of the axle (A4) on the track section (GA) is obtained, a position indication (PA(s)) being derived from the said position signal by the assignment of reference values, characterized in that, irrespective of the position signal (f(s)) obtained, an alarm signal (U(t)) is generated when the axle (A4) passes a definite fixed point (P) of the track section (GA), in that a check is made as to whether there is a deviation of the position signal (f(s)) obtained for this point or of the derived position indication (PA(s)) from a desired value (f(s_p)) valid for this point (P), and in that a deviation-reducing follow-up control of all the position signals (f(s)) or a correction of the assignment of the reference values to the position signals (f(s)) is carried out.
2. Method according to Claim 1, characterized in that the fixed point (P) is provided in the middle region of the track section (GA).
3. Method according to Claim 1 or 2, characterized in that the follow-up control or the correction is carried out only when significant deviations of the position signal (f(s)) or of the position indication (PA(s)) from the desired value (f(s_p)) which are in the same direction are detected more than once.
4. Method according to one of the preceding claims, characterized in that the alarm signal (U(t)) is generated by a wheel sensor (RS).
5. Method according to one of Claims 1 to 3, characterized in that the alarm signal U(t)) is generated by a switch which short-circuits the rails (S1, S2) when the axle (A4) passes.
6. Method according to one of the preceding claims, characterized in that when the last axle (A4) of the vehicle (F) passes the fixed point (P) is determined.
7. Method according to one of Claims 1 to 6, characterized in that at least the last two position signals (f(s, t₄); f(s, t₃)) at the times (t₄,t₃) of the last two alarm signals (U(t₄);U(t₃)) are stored in each case.
8. Method according to one of the preceding claims, characterized in that the deviation of the position signal (f(s)) or of the position indication (PA(s)) from the desired value (f(s_p)) in the vicinity of the fixed point (P) is detected by means of a suitable smoothing function.

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