DE2715348A1 - Counting arrangement for axle and wheel of rail vehicles - uses coil system with open field near identification point to generate magnetic field for passing metal detection - Google Patents

Abstract

The axle and/or wheel counting arrangement is applicable to railed vehicles. It evaluates the passing of metal objects by an identification point. A coil system (E) in a combination of a.c. circuits (EAK) generates an alternating electromagnetic field. It is near, but not in contact with the identification point. Change of the open circuit coil system (E) impedance caused by the object to be identified, is evaluated for selective pulse generation. In normal working the feed-back (R) maintains the frequency correction at the generator (G). This is ensured by a blocking element (S) making the feed-back (R) ineffective for the duration of the ANN'S (U) output signals.

Description

Axle counting device

vDic invention relates to an electronic device for axle and / or wheel counting of rail-bound vehicles by evaluating the movement past of metallic objects at an identification point and is for use determined in automatic axle counting systems in railway operations.

In modern railway signaling technology is the automatic track vacancy detection an indispensable means of keeping trains running quickly, safely and economically to design. The principle of the automatic track clearing tune is that the routes and stations are divided into track sections for signaling purposes and these track sections are automatically classified as "occupied" in the presence of railway vehicles and are reported again as wfreiH after the passage.

There are different ways to monitor the individual track sections Methods of application, of which the automatic axle and / or wheel counting are special Is important because it can be used freely to a large extent and has a particularly high level of operational reliability having.

Purely the difficult conditions of the railway operation are to the automatic Axle and / or wheel counting electronic measuring devices are particularly suitable. There when rail vehicles run over the rails, accelerations of up to 2000 g must occur at the identification point immediately next to or at the Rail itself attaching device have the lowest possible mass.

Electronic measuring devices can easily be designed in such a way that that at the identification point at or at the rail itself only a simple direction of action (measuring sensor) through the wheel (pair of wheels, axle) the rolling past railway vehicles is directly influenced and therefore only Must have low mass, is attached and the remainder of the electronic Measuring device is housed in its own electronics connection box, the is electrically connected to the action device (sensor). In this electronics junction box is the action of the individual wheels (wheel pairs, axles) on the device (MeßfUhler) evaluated for electrical single impulses. The accommodation of the electronics connection box can be between the tracks or, more advantageously, at a suitable location next to the track structure be made.

In general, electronic axle and / or wheel counting systems are used designed in such a way that the individual electrical impulses are passed on to a central point and in this the axle and / or wheel count itself and the evaluation for Track vacancy is made.

An important requirement for automatic axle and / or wheel counting systems It is of this design that the influencing of the influencing device (menu sensor) by the rolling by wheel (pair of wheels, axle) of the railway vehicles takes place reliably, but an influence by other vehicle parts, such as Magnetic rail brakes or hanging metal parts, etc. reliably avoided will.

Furthermore there is an automatic axle and / or wheel counting and evaluation for track vacancy it is necessary that the direction of movement of the railway vehicles is evaluated with. This is done in two ways, that at the identification point Two action devices (sensors) are attached to the Cleis at a short distance from one another will. The sequence of influencing the two influencing devices (sensors) at the identification point is either already in the electronics connection box or only in the central station in a manner known per se for the axis and / or Wheel count evaluated.

With. Help these two close to each other at or near the Rail-mounted action devices (sensors) can not only determine the direction of movement of the railway vehicles are detected, but also during shunting (creeping Operation) via the two action devices (sensors) a clear, reliable Detection of the individual axles (wheels) of the railway vehicles take place. Likewise is from the duration of the succession of the individual impulses from the two action devices (Measuring sensor) a speed measurement of the acting devices (measuring sensor) rolling railroad vehicles possible.

In addition, by monitoring the sequence of the pulses the operational safety of the automatic of the two devices (measuring sensors) Axle and / or wheel counting systems are further increased, as each of the two action devices (MeßfUhler) consecutive pulses must be emitted and failure to comply this condition to an error display of the electronic measuring device for automatic Axle and / or wheel counting can be evaluated.

So far there have been different designs of electronic measuring devices known for automatic axle and / or I? ad payment systems. In the Austrian Patent Specification No. 200616 describes an electronic measuring device, bci which at the identification circuit is the inductance of a self-exciting generator serves as a coil pair on both sides of the rail as an action device and the "coupling" between the two coils this pair of coils by the wheel of the rolling past Railway vehicle changed and this change in the electronics connection box is evaluated for character output.

Another embodiment of an electronic measuring device for automatic axle counting systems, Austrian patent no. 283443.

At this facility you will also be at the identification point Coils attached to both sides of the track, one of the coils acting as a transmitter coil and the other coil is used as a receiving coil ud by the wheel of the rolling by Railway vehicle the transmission and thus the "coupling between transmission and Reception coil changed and this change continued in the electronics connection box is evaluated.

In patent specification No. 24822 of the German Democratic Republic an embodiment of an electronic measuring device for automatic axle Counting systems described, according to which at the identification point as an action device the inductance or the capacitance of a resonant circuit is used and a wheel of a railway vehicle rolling past a change in the frequency of the Resonant circuit causes and this frequency change U via selective amplifier for Evaluation reached.

Further currently known electronic measuring devices for automatic Axle counting is described in the following technical literature: a. Elsners Taschenbuch der Eisenbahntechnik 1973 (Scite 187 to 232) The electronic axle numbers Design standard electrics Lorenz Az 65 SEL b. Siemens magazine 45 (1971) supplement "Railway technology" (pages 164 to 167) Electronic axle counting for monitoring track sections c. Armin Ronacher: Diploma thesis from September 1973 carried out at the Institute for Low Frequency Technology at the Technical University in Vienna Touchless rail contact for one electronic axle counter for railway safety technology.

The currently known ones listed in the aforementioned publications Method for electronic measuring devices for automatic axle counting are based either on the evaluation of the change in the frequency of a resonant circuit or but on the evaluation of the change in the degree of coupling, or change in the magnetic Flow between two coils.

For all of these currently known processes, one must be sufficient reliable identification a relatively low frequency (approx. 5000 Hz> application find, since the components used for identification act magnetically "soft" must, or their effective permeability, the magnetic flux correspondingly strong must influence.

In addition, cs is required in these previously known methods, <ate for reliable identification and avoidance of interference in the facilities additional filters, selective amplifiers, steeping processes, e.g.

Frequency weighting, bridge switching or similarly acting arrangements, or methods are used, which requires a great deal of effort.

The relatively low frequency in the indicator circle of the currently known Versions of the electronic measuring devices for automatic .4axle payment also means that the required coils on the action devices are relative must be made large and therefore also have a relatively large mass. In view of This mass lies in the already mentioned enormous impact stress on these components at the limit of the securing cross-sections considered to be safe, if signs of fatigue must be taken into account for assessing the service life.

Glider, the relatively low frequency is close to the interference voltages, caused by the harmonics of the traction current, especially in traction vehicles with phase control (thyristor control).

Finally, most of the previously known methods take place an influence of the magnetic alternating field by the magnetic properties of the wheel rolling past the action device. The magnetic properties the wheels of railway vehicles may change considerably if When braking, the wheels reach temperatures that are above the Curie point, whereby the security of the identification is reduced.

hir electronic measuring devices for automatic axle counting Furthermore, methods are known which work according to the microwave echo method. These facilities work reliably but require the current status the technology unhinderedly great effort, if its implementation all meteorological and other external influences.

The object of the invention is to provide the electronic measuring device for to carry out automatic axle and / or wheel counting so that the disadvantages of Previously known designs are avoided by the fact that much higher frequency (approx. 50 to 80 kFiz) can be used, which results in both a lower Mass for the action device (sensor), as well as a larger frequency spacing to the interference voltages of the traction current results.

According to the invention this is achieved in that in a combination of alternating current circuits a coil arrangement generating an electromagnetic alternating field attached with an open circle close to, but without contact, the identification point and the change in impedance caused by the object to be identified of the open-circle coil assembly is evaluated for selective pulse generation will.

The electronic measuring device for automatic axis and / or Wheel counting can be carried out so that the change in the impedance of the coil assembly with an open circuit through a loss resistance measurement for selective pulse generation is evaluated. This embodiment requires little effort, any known one Arrangement for impedance measurement, e.g. a simple current-voltage measurement, can be used.

Another embodiment of the electronic measuring device for automatic axle and / or wheel counting is given by the fact that the change the impedance of the open circuit coil assembly by phase measurement selective pulse generation is evaluated. Phase measurement is also easy to be carried out, it also provides information for an additional long-term frequency correction of the generator of the measuring device.

An extension of the embodiment of the electronic measuring device for automatic axle and / or wheel counting results from the fact that the change the impedance of the open circuit coil assembly by loss resistance measurement and phase measurement registered independently and through logical linkage for selective Pulse generation is evaluated. Due to the separate impedance and phase measurement and the logical combination of these two measurements increases operational reliability Achieved against external influences.

The required measurements in the electronic measuring device for automatic axle and / or wheel counting can be simplified so that the loss resistance measurement and / or the phase measurement on the evaluation of the exceeding and falling below two amplitude limit values is reduced. The measurements of the impedance or the phase measurement are thus related to the measurement reduced by limit values and there is a simplification of the measurement methods on the Measurement of digital values achieved and thus the measurement reliability increased.

The electionic menu device for automntichen axis and / or Wheel counting according to the invention can be expanded to include the assembly to influence the phase measurement via a feedback of the generator of the ring device it becomes that a long term frequency correction is achieved. This becomes the permanent Frequency constancy of the generator of the measuring device under the most varied of operating conditions, especially under the vastly different temperatures in the lead electronics connection box and thus the constancy of the entire measuring device is ensured.

A supplement to the electronic measuring device for the automatic Axle and / or wheel counting in the version with "feedback" for the generator is still given in that a locking member is provided, which the task has, the feedback is ineffective during the pulses emitted for identification close. This will influence the generator of the measuring device during the transmission of pulses for axle and / or wheel counting prevented by the feedback.

The electronic measuring device for automatic axis and / or Wheel counting according to the invention will now be illustrated with reference to the figures Exemplary embodiments described in more detail: Fig.l shows a block diagram of the measuring device according to the invention in a simple embodiment. 2 shows a block diagram of the Measuring device according to the invention in an expanded version. 3 shows an exemplary embodiment the basic attachment of the action device (measuring sensor) to the rail.

The exemplary embodiment shown in Figure 1 of an electronic Measuring device for automatic axle and / or wheel counting according to the invention Requires an action device E, a blektronic connection '. box EAK , in which the individual assemblies of the measuring device are housed, with the acceptance point S for the output impulses.

A generator G with a fixed, discrete frequency feeds via a compensation network No open coil arrangement generating a higher frequency alternating field than Action device (sensor) E attached to the identification point on the rail will. The compensation network K - consisting primarily of capacitance and ohmic linear and / or non-linear resistances - signal voltages are taken and corresponding assemblies for evaluating the change in impedance Z and the change in phase q fed. These two modules have fixed limit value thresholds and deliver eo digital signals to an AND operation U, from which the direct current output pulses to the output Off. These DC output pulses are generated by the Output from the electronic measuring device for automatic axle and / or wheel Counting supplied via a corresponding line to the central office and in this the evaluation for automatic axle and / or wheel counting and track vacancy detection performed.

At the identification point, the acting device E serving open coil arrangement "attached to the rail so that the electromagnetic Alternating field of this coil arrangement through the wheel flange of rolling past wheels Railway vehicles affected, one mechanical contact between the "open coil arrangement" and the wheel flange deo Eioenbahnfahrzcuges, however, safe is avoided. The different dimensions of the wheel flanges (wear) of the Railway vehicles, as well as the play of the axes with the pairs of wheels within the tracks must be taken into account when attaching the action device (open coil arrangement ") will.

3 shows an embodiment of these attachments. On the rails Sch runs a wheel R with the flange Sp of the railway vehicle. The exposure device (open coil arrangement ") takes, because a relatively high frequency in the measuring device according to the invention is used, only a small space and can therefore be attached below the upper edge of the rail. Taking into account tolerance the movement of the wheel flange Sp on the rail rail can influence this device E1 between the rail Sch and the flange Sp or as an action device E2 must be attached outside of the flange Sp.

The attachment of the action device (measuring filter) below the The upper edge of the rail is particularly advantageous because it allows this direction of action is particularly well protected against mechanical damage.

It can also be useful to have two at the identification point Action devices E1 and g2 directly opposite, as shown in Fig. 3, to be attached so that the running of the flange Sp with its tolerances is reliably detected will.

When approaching a wheel flange (generally made of steel or steel alloy) of a Fisenbahnfahrzeures to the serving as Einviirk device E "open coil arrangement" the electromagnetic alternating field of this coil arrangement is influenced in the way that in the magnetic circuit with lossy parts are included and thus the inductance value for this coil arrangement if the frequency is selected accordingly the impedance value remains practically unchanged due to the increase in the losses in Amount is changed and its phase angle also changes.

A change in the losses and therefore the impedance of the electromagnetic Circle of the open coil arrangement "when approaching a wheel flange of a railway vehicle occurs in any case (with a different amount), regardless of the material of the flange itself, regardless of its permeability value. It is just necessary that metallic parts in the open electromagnetic circuit of the coil assembly reach. This also enables reliable identification, for example, by braking Reached over the Curie point of heated wheels and this embodiment is one electronic measuring device for automatic axle and / or wheel counting according to of the invention future-proof with regard to plastic wheels, which may be could be used in railway operations. E.g. through a metal pad on the plastic wheels can be identified in the measuring device according to the Invention to be made.

The 9ceinvllussung the action device E by rolling past As already described, RRder of railway vehicles acts as a change (Lightening) the impedance of this action device (open coil arrangement) E, as well as in a change in the phase angle.

The change in the impedance value is used for evaluation in the assembly the impedance change Z in amount and the phase change in the assembly for evaluation of the phase angle qD evaluated as separate digital signals.

Any known arrangement can be used to measure impedance of the phase angle is a simple phase detector with a reference phase from the same Measurement AC voltage suitable.

The digital signals from the module to evaluate the change in impedance Z and for measuring the phase angle t are forwarded to the AND operation U and only if a digital signal is received from both modules at the same time, a digital signal as a direct current pulse is transmitted from the and connection U the output passed on.

Through this double check (change in impedance and change in phase angle) is an increased security of the electronic measuring device for automatic Axle and / or wheel counting against interference and the possibility of monitoring of the assemblies. The measuring device can thus be expanded with little effort be that when only one digital signal 5 is output to the AND link U a Error alarm is triggered.

The reliable function of the electronic measuring device for the automatic Axle and / or wheel payment according to the invention requires strict compliance the predetermined, discrete frequency of the generator G. About the frequency constancy of the generator G, the measuring device is expanded as shown in FIG. that a long-term frequency control of the generator G takes place.

From the assembly to evaluate the phase change q becomes permanent a measured value that corresponds to the phase angle of the action device (open coil arrangement) E corresponds to a return R supplied. This measured value has under normal operating conditions (Compliance with the predetermined discrete frequency of the generator G) a certain Value.

If the frequency of the generator G changes, it also changes Phase angle of the action device B and thus also that of the feedback R supplied Measured value.

This change in the measured value is evaluated in the feedback R and with a relatively large time constant, the generator G influences so that a frequency correction takes place on the predetermined discrete frequency.

During normal operation of the electronic measuring device to the automatic Axle and / or wheel counting occurs when the wheels of railway vehicles roll past at the action device E on impedance and phase changes.

For these normal operations, the return R must be in their Function of the frequency correction of the generator G "holding" (that is: the instantaneous Maintaining the control value). This is via the locking member S by which the return R for the duration the Auscang nale of the AND link U in its function of influencing the generator G becomes ineffective dynamically. Since the influence of the generator G from the feedback R takes place with a relatively coarse time constant, a frequency correction is made here during of the identification process (identification of wheels rolling by) safely avoided.

In the embodiment of the electronic measuring device for automatic Axle and / or wheel counting according to FIG. 1, the identification pulses are sent to the Output Off emitted as DC output pulses. Because the transmission of direct current pulses is only possible over limited line lengths, shows the embodiment of the measuring device according to the invention in Fig.2 a supplement for converting the direct current pulses in alternating current pulses. This takes place in the line converter L, which is connected to the output Aus1 is followed by the AND link U and in which the direct current pulses converted into alternating current impulses and then fed to the output Aus2. from this output Aus2 of the electronic measuring device for the automatic axis and / or Wheel counting can use the identification pulses as alternating current output pulses can be transmitted to the central office over longer cable lengths.

The electronic measuring device for automatic axis and / or Wheel counting of rail-bound vehicles according to the invention brings against the previously known versions, in which at the identification point by the object to be identified either a change in the degree of coupling between two coils (coil arrangements) or an influencing of a sensor that one Frequency reduction in the measuring equipment results in numerous Advantages. Because the loss resistance and thus the impedance and the phase angle is measured by a Rinffekt device attached to the identification point, the measuring frequency can be significantly higher (approx. 50 to 80 kHz) than with the previously known Versions (approx. 5 kflz) can be selected.

So that the components of the measuring device, in particular the The action device to be attached to the identification point is much smaller significantly smaller in volume and thus also in mass than with the previously known Executions. In the embodiment according to the invention, the small, lightweight action device eanz just next to the rail (under the upper edge of the rail) and In this way, damage is largely avoided, such as those caused by automatic track tamping machines or other external influences that are difficult to control can arise. The minor one The mass of the impact device is in consideration of the enormous impact stress of particular importance when driving over the identification point.

Another advantage due to the relatively high frequency of the embodiment According to the invention, the greater distance to the harmonics of the traction current is especially for traction vehicles with phase control (thyristor control) and the increased security of the measuring device against being influenced by the interference voltages caused by the traction current. Complicated expensive filters, selective amplifiers or other additional devices against interference voltages are not required.

On the other hand, the measuring frequency of 50 to 80 kHz is still low: enough, in order to safely avoid disturbance of other equipment by radiation. Disruptions due to radiation, this would only have to be taken into account with frequencies from approx. 150 kMz.

Furthermore, the measurement of two variable quantities (impedance and phase) an increased security against other external influences, e.g. remote action from lightning strikes, short-circuit currents of traction and it can do this double measurement can also be evaluated for self-monitoring of the measuring device.

Since the influence of impedance and phase of the interlocking device when approaching a wheel flange of a railway vehicle in any case (with different Amount) occurs, regardless of the material of the flange itself and also little reliable identification is given depending on its permeability value. It is only necessary that metallic parts pass close to the action device will. It is thus a reliable identification of the wheel flanges, also for example achieved by braking over the Curie point of heated wheels (wheel flanges') and if plastic wheels should be used in railway operations, can E.g. through a simple metal pad on the plastic wheels to identify them be made.

The higher Mcßfreqcunz also has the advantage that at high speeds the railway vehicles to be identified or their number of axles for each individual identification (each individual wheel, wheel axle) a higher number of periods of the alternating voltage Is available and therefore the demodulation time constants are chosen to be small can and thus also a safe separation in the signal processing of the selective Impulses for the identification of double or multi-axle vehicles, even with high ones Speeds is achieved.

The measuring device according to the invention works with an action device (sensor), which represents a two-pole operation, which gives the advantage of that at the identification point only one action device <sensor) - on one rail side - must be attached, while most of the previously known Versions represent a four-pole operation at the identification point On both sides of the rail an action device (sensor), so a total of two Action devices (sensors) required.

Claims (7)

Claims 1. Device for axle and / or wheel counting of rail-bound Vehicles by evaluating the movement of metallic objects past a Identification point, characterized in that in a combination of alternating current circuits (EAK) a coil arrangement (E ) attached with an open circle close to the identification point, but without any transmission and the change in impedance caused by the object to be identified of the coil arrangement (E) with an open circuit for selective pulse generation will. 2. Device for axle and / or wheel counting of rail-bound Vehicles according to claim 1, characterized in that the change in impedance the coil assembly (E) with open circuit by a loss resistance measurement (Z) is evaluated for selective pulse generation. 3. Device for axle and / or wheel counting of rail-bound Vehicles according to claim 1, characterized in that the change in impedance the coil assembly (E) with open circuit by a phase measurement (T) for selective Pulse generation is evaluated. 4. Device for axis and / or Rd counting of rail-bound Vehicles according to claim 1, characterized in that the change in impedance of the coil arrangement (E) with an open circuit by measuring loss resistance (Z ) and phase measurement (q) independently registered and linked through loginche (U) is evaluated for selective pulse generation. 5. Device for axle and / or wheel counting of rail-bound Vehicles according to one of the preceding claims, characterized in that it is marked. that the loss resistance measurement (Z) and / or the phase measurement (T) on the evaluation exceeding and falling below two amplitude limit values is reduced. 6. Device for axle and / or wheel counting of rail-bound Vehicles according to one of the preceding claims, characterized in that from the module for phase measurement (to) the generator via a feedback (R) (G) the device is influenced so that a long-term frequency correction is achieved will. 7. Device for axle and / or wheel counting of rail-bound Vehicles according to claim 6, characterized in that a locking member (S) is provided is which has the task during the impulses given for identification to make the return (R) ineffective.