METHOD AND ARRANGEMENT FOR MONITORING TRACK SECTIONS

Description

TECHNICAL AREA OF INVENTION

[0001] The invention relates to a method and an arrangement for monitoring track sections by means of wheel sensors, in particular by means of double sensors consisting of two sensor elements arranged spatially offset in the direction of the track. BACKGROUND OF THE INVENTION

[0002] It has long been known to monitor track sections in rail transport to determine whether a rail vehicle has at least partially entered a track section or whether the track section is clear – as described, for example, in document DE 10 2013 224346 A. For this purpose, wheel sensors, typically in the form of so-called dual sensors consisting of two sensor elements spatially offset in the direction of travel, are installed at opposite ends of the track section to be monitored. When a vehicle passes over these sensors, counting pulses are generated. By comparing the counting pulses at both ends of the monitored track section, it can then be determined whether the track section is clear or occupied.

[0003] Typically, inductive proximity switches are used as sensors, such as those known from DE 23 26 089 A1, DE 32 34 651 A1, and DE 33 13 805 A1. They comprise at least one sensor element, typically in the form of an AC-powered resonant circuit coil, which responds to relative movement between the sensor element and a metallic object, e.g., a railway wheel rolling past the sensor element, and triggers a pulse that can be used, for example, for counting or triggering specific control signals. If the sensor element is an AC-powered resonant circuit coil, also called a response coil, it is typically connected to a capacitor to form an LC resonant circuit and is located in a quiescent current monitoring circuit.When a metallic object moves through the electromagnetic field of the coil, the electrical behavior of the monitoring circuit changes, allowing counting or control pulses to be generated via appropriate trigger circuits in a manner known per se. If a proximity switch has two sensor elements arranged in series, the direction of travel and, if applicable, the speed can also be determined from the sequence in which the sensor elements respond.

[0004] Track section monitoring using proximity switches of the type mentioned has proven its worth in practice for many years. However, the increasing density of rail traffic, especially public transport in metropolitan areas where, for example, subways run every minute during peak hours, places higher demands on the availability of such monitoring systems. If a track that is actually clear is reported as occupied, this can lead to massive disruptions in traffic. Of course, the consequences can be catastrophic if a track section that is actually occupied is reported as clear. Therefore, the standard design of such monitoring systems is always such that, in cases of doubt, a track section that is actually clear is more likely to be reported as occupied than an occupied track section to be erroneously reported as clear.

[0005] To increase reliability and operational safety, i.e., the reliability of detecting, for example, the wheels (and thus the corresponding number of axles) of a passing rail vehicle (although in the railway sector it has become customary to speak of axle counting rather than wheel counting), numerous proposals have already been made, some of which have even been incorporated into the safety regulations required by railway operators. These proposals fall roughly into two categories: One category concerns the improvement of the sensors themselves, the other category concerns the arrangement and interconnection of the sensors to form redundant axle counting circuits and thus reliably compare the number of axles entering a monitored track section with the number of axles exiting the track section.

[0006] A proposal of the first category (improvement of the sensor) can be found in DE 199 15 597 A1, which proposes a wheel sensor with two AC-powered resonant circuit coils to make it possible to suppress induced interference voltages and to achieve a particularly high insensitivity to interference from electromagnetic interaction with the eddy current brakes used in many rail vehicles when they operate in the detection range of the coils.

[0007] Proposals of the second category (improvement of the arrangement and interconnection of the sensors) can be found, for example, in DE 196 06 320 A1, which proposes a method for dealing with hardware failures in track vacancy detection using axle counting, EP 0 662 898 B1, which proposes a device for automatically correcting axle counting errors, and EP 1 498 338 B1, which proposes a method for determining the occupancy status of a track section, especially after a restart of an axle counting system.

[0008] DE 10 2005 048 852 A1 discloses a method and an arrangement according to the preambles of claims 1 and 8. To increase the reliability of the detection, particularly on heavily frequented lines, and especially to ensure operational safety even when a wheel sensor fails during peak hours and immediate maintenance of the system would lead to service interruptions, the aforementioned document discloses a redundant design of the axle counting circuits formed by the wheel sensors. In this design, two wheel sensors are arranged at opposite ends of a track section to be monitored, and each wheel sensor of one end is linked to each wheel sensor of the opposite end to form two axle counting circuits. If the wheel sensors arranged in one end are designated A and B, and the wheel sensors arranged in the opposite end are designated C and D, the axle counting circuits AC, AD, BC, and BD are formed.

[0009] In contrast, to simplify evaluation, the two wheel sensors in one end region are classically linked to only one wheel sensor in the opposite end region, thus forming, for example, axle counting circuits AC and BD. If one sensor fails, another axle counting circuit remains available. If a sensor in the second axle counting circuit fails, no axle counting circuit is available, regardless of which end region the sensor is located in. According to the teaching of DE 10 2005 048 852 A1, however, a functioning axle counting circuit would still be available even if a wheel sensor failed in each end region.

[0010] However, it has become apparent that implementing the solution described in DE 10 2005 048 853 A1 is not trivial. If two wheel sensors in opposite end sections actually fail, the electronics must be able to decide which of the four axle counting circuits should then be disregarded. Furthermore, this solution is not readily scalable, i.e., transferable to track layouts with branched track sections, because a simple turnout with three end sections already creates eight axle counting circuits, four end sections create sixteen, and so on.

[0011] Another possibility for linking redundant wheel sensors located at opposite ends of a track section to be monitored is shown in US 2016 / 0332644 A1. In this method, the signals from all wheel sensors listed as "detection points" in the document are sent to a higher-level axle counting unit. This higher-level axle counting unit selects, for each end section, one of the two wheel sensors located in the same end section according to complex evaluation criteria—the so-called "best working detection point"—and forms an axle counting circuit from the selected wheel sensors. However, it has been shown that this approach has significant disadvantages in practice, particularly regarding the feasibility of retrofitting and obtaining approval for such a system from the relevant authorities or railway operators.

[0012] For example, to apply the teaching of US 2016 / 0332644 A1, two wheel sensors must be provided in each end area, whereas in practice, it is often only required to create redundant axle counters from certain existing wheel sensors by linking the existing wheel sensor with a second wheel sensor located in the same end area. In other words, it is often desired to link an existing axle counter unit with axle counters, whereby some axle counters should include several wheel sensors, while others should only include one wheel sensor each.

[0013] A particular problem arises from the fact that, according to US 2016 / 0332644 A1, all wheel sensors must be connected to the axle counting unit, which is usually done via wired connections as specified by the respective railway operator or due to regulatory requirements. The end sections to be monitored are often several hundred, sometimes even over a thousand meters apart, so that rewiring them would be a considerable undertaking. Even when adding another wheel sensor to an existing one, new cables must be laid, as the existing cables, which are typically four-core, do not allow for the connection of the additional sensor. Retrofitting existing axle counting systems requires a new axle counting unit designed to evaluate the signals supplied by the various wheel sensors, which necessitates new approval from the relevant authorities or the respective railway operator.However, the corresponding approval procedures are complex and costly. REVELATION OF THE INVENTION

[0014] The invention is based on the objective of providing a method and an arrangement for monitoring track sections using wheel sensors, in which the evaluation can be carried out in a particularly simple and error-free manner, so that the method and the arrangement are arbitrarily scalable, i.e., can be implemented with high availability even in complex arrangements of track sections with multiple switches, such as those frequently found in shunting areas, and the method and arrangement should be particularly flexibly configurable, so that combinations of redundantly designed and non-redundantly designed axle counting points are also possible.

[0015] The problem is solved by a method with the features of claim 1 or an arrangement with the features of claim 8. The corresponding dependent claims relate to advantageous embodiments and further developments.

[0016] The invention is based on the novel approach of not designing the axle counting circuits redundantly, i.e., creating as many axle counting circuits as possible from the existing wheel sensors, but rather creating redundant axle counting points in those end sections where required and connecting only these axle counting points to each other, so that only a single axle counting circuit is formed for each track section. In this process, any redundant wheel sensors are not linked in a higher-level axle counting unit, but rather in the opposing end sections.In other words, on the one hand, redundancy is shifted from the axle counting circuits to the axle counting stations, which, as explained below, significantly simplifies the evaluation and makes the process and arrangement easily scalable. On the other hand, wheel sensors are interconnected in the redundantly designed axle counting stations – and not in a higher-level axle counting unit – which offers considerable advantages. For example,When retrofitting wheel sensors to create redundant axle counting points, the new wheel sensors are not wired to an existing axle counting unit. A particular advantage of the invention is that, despite the conversion to redundant axle counting points, existing axle counting units can continue to be used, since nothing changes from the perspective of the respective axle counting unit: it continues to receive only one signal from each axle counting point, regardless of whether the axle counting point comprises only one wheel sensor or several wheel sensors. This also eliminates the need for the costly re-certification of the axle counting unit.

[0017] The term "redundantly designed axle counting station" refers to an axle counting station in which one or more of the wheel sensors can fail without causing the axle counting station to fail. When it is stated that wheel sensors are interconnected "in redundantly designed axle counting stations," this means, according to standard technical understanding, that the interconnection of the wheel sensors takes place near the track, where the wheel sensors are located. The wheel sensors forming an axle counting station do not necessarily have to be housed in a common enclosure; an axle counting station can therefore comprise spatially separate units such as wheel sensors and voters. Typically, the voters are located in a track connection box to which the respective wheel sensors are connected. The track connection box is then connected to an axle counting unit.

[0018] The term "opposing end sections" refers to the end sections of a track segment that must be monitored to determine whether the track segment is clear. In this sense, a simple turnout comprises three opposing end sections: one at the leading edge and two at the trailing edge.

[0019] In one embodiment, the two axle counters are linked together in a 1oo2 architecture to form the axle counter circuit. Here, the term "XooY architecture" (pronounced "X out of Y architecture") denotes a logical evaluation, where Y represents the number of linked elements and X represents the number of elements that must fail to cause a complete failure of the evaluation. The evaluation can be implemented as a hardware circuit or in software. In a 1oo2 architecture, two elements are linked, and a complete failure occurs if one of these elements fails. The linked elements in such an architecture can be individual sensor elements of a dual sensor, but also complete dual sensors or wheel sensors, axle counters, or axle counter circuits.The term "evaluation failed" here refers to the situation where it is no longer possible to evaluate the information provided by the individual elements. Therefore, the greater the relative size of X compared to Y (where X can, of course, be at most equal to Y, since the maximum number of elements that can fail is equal to the number of elements present), the greater the availability of the evaluation.

[0020] In one embodiment, the two wheel sensors of a redundantly designed axle counting station are linked together to form the respective axle counting station in a 2oo2 architecture.

[0021] In another embodiment, two dual sensors are used as wheel sensors to form a redundant axle counting station. Each dual sensor consists of two sensor elements spatially offset in the track direction, and the two sensor elements of each dual sensor are linked together in a 1oo2 architecture. If one sensor element fails, the corresponding dual sensor fails, but a functioning dual sensor is still present in the respective axle counting station.

[0022] Alternatively, if two dual sensors are used as wheel sensors to form a redundant axle counting station, with each dual sensor consisting of two sensor elements spatially offset in the track direction, the four sensor elements of the two dual sensors of a redundant axle counting station are linked together in a 3oo4 architecture to form the respective axle counting station. Preferably, the four sensor elements are arranged spatially offset from each other in the track direction at each end area.

[0023] In the latter two cases (use of dual sensors as wheel sensors), it is advantageous to proceed as follows: in the redundantly designed axle counting stations, counting pulses are generated using the two dual sensors when at least two spatially offset sensor elements of the four sensor elements respond with a time offset.

[0024] A major advantage of the invention is its easy scalability. If the monitored track section has more than two end areas, as is the case with a turnout, only one axle counter is added per end area. In contrast, with the prior art solution described above, where each of the two wheel sensors in one end area is linked to each wheel sensor in the opposite end area, the number of axle counter circuits increases exponentially. Therefore, if the monitored track section comprises a turnout with one end area at the tip and two end areas at the root, it is sufficient to form only one axle counter circuit from the axle counter at the tip and the two axle counters at the root.If a further track branch off from one of the track sections at a further junction point, and if a further axle counting point is provided at an end section of the further track section opposite the further junction point, then, according to the invention, the further axle counting point can be integrated into the axle counting circuit. Advantageously, therefore, only one axle counting circuit is formed for each monitored track section.

[0025] In an arrangement according to the invention for monitoring track sections by means of wheel sensors arranged in opposite end regions of a track section to be monitored, axle counting stations are formed from the wheel sensors in the opposite end regions, wherein at least one of the axle counting stations is designed redundantly and comprises two interconnected wheel sensors, wherein each redundantly designed axle counting station comprises a voter for linking the two respective wheel sensors, and wherein a single axle counting circuit is formed from the axle counting stations. The voters can be implemented as a hardware circuit or by software.

[0026] In one embodiment, the two axle counting stations are linked together in a 1oo2 architecture to form the axle counting circle.

[0027] In one embodiment, the voters of a redundantly designed axle counting station are designed to link the respective wheel sensors together in a 2oo2 architecture.

[0028] Preferably, the wheel sensors of a redundant axle counting station are each a pair of sensors, with each pair consisting of two sensor elements spatially offset in the track direction, and the two sensor elements of each pair being interconnected in a 1oo2 architecture. Alternatively, if the wheel sensors of a redundant axle counting station are each pair of sensors, with each pair consisting of two sensor elements spatially offset in the track direction, the drivers of a redundant axle counting station can be configured to interconnect the four sensor elements of the two pairs of sensors to form the respective axle counting station in a 3oo4 architecture. Advantageously, the four sensor elements intended to form a redundant axle counting station can then be spatially offset from each other in the track direction.In the aforementioned cases, each redundantly designed axle counter can be configured to generate counting pulses using the two dual sensors when at least two spatially offset sensor elements of the four sensor elements respond with a time delay. Evaluation electronics can be provided for this purpose.

[0029] If the track section to be monitored is a branched track section with more than two end sections, such as a turnout, and an axle counter is provided in each end section, the axle counters can be linked to form a single axle counter circuit. For a simple turnout with one track section at the point and two track sections at the root, it is therefore sufficient to form only one axle counter circuit using one axle counter at the point and two axle counters on the two track sections at the root.

[0030] In a preferred embodiment, the voters of redundantly designed axle counters are each connected to an axle counter unit via an interface to form the axle counter circuit. The wheel sensors of each redundantly designed axle counter are also connected to their respective voters via an interface, and all interfaces are defined identically. This allows for particularly simple retrofitting of existing systems. The interfaces can be, for example, power interfaces, i.e., cables, through which the axle counter unit supplies current to the axle counters and monitors its flow. However, they can also be virtually any other interface, such as a CAN bus.

[0031] Further details and advantages of the invention will become apparent from the following purely exemplary and non-limiting description of embodiments in conjunction with the drawing comprising nine figures. BRIEF DESCRIPTION OF THE DRAWING

[0032] Fig. 1 shows a highly schematic top view of a track section with four wheel sensors. Fig. 2 shows a schematic of the response of two sensor elements of a dual sensor when a metallic train wheel passes by. Fig. 3 shows a circuit diagram of a first arrangement according to the prior art. Fig. 4 shows a circuit diagram of a second arrangement according to the prior art. Fig. 5 shows a circuit diagram of a first embodiment of the invention. Fig. 6 shows an evaluation diagram of the first embodiment of the invention. Fig. 7 shows a circuit diagram of a second embodiment of the invention. Fig. 8 shows an evaluation diagram of the second embodiment of the invention. Fig. 9 shows a highly schematic representation of a simple turnout with six wheel sensors arranged to monitor the individual track sections of the turnout. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0033] Fig. 1 Figure 1 shows a schematic top view of a track section to be monitored, designated in its entirety as 10, of a track consisting of two rails 14 and 16 laid on a number of sleepers 12, of which for the sake of clarity only some have been provided with reference numerals, wherein in two opposite end areas 18 and 20 of the track section to be monitored 10 two wheel sensors A and B and C and D respectively are arranged.

[0034] In this embodiment, each wheel sensor A, B, C, D is designed as a dual sensor consisting of two sensor elements A1, A2, B1, B2, C1, C2, D1, D2, wherein each dual sensor is of the "inductive proximity switch" type and the individual sensor elements A1, A2, B1, B2, C1, C2, D1, D2 are AC-powered resonant circuit coils. However, the invention is not limited to the use of dual sensors and, in particular, inductive proximity switches – in principle, any type of sensor that enables the detection of a wheel or axle passing by is suitable for realizing the inventive concept. Dual sensors, however, have the significant advantage of detecting the actual passing of a wheel or axle and not merely a so-called "pendulum swing," by checking whether the sensor elements of the respective dual sensor, which are arranged spatially offset one behind the other along the track, are triggered.

[0035] In the illustrated embodiment, the arrangement is such that a train traveling from left to right in the drawing first enters the detection areas of sensor elements A1 and B1, then the detection areas of sensor elements A2 and B2. A train traveling from right to left would, in the illustrated example, first enter the detection areas of sensor elements C1 and D1, and then the detection areas of sensor elements C2 and D2; this arrangement is purely illustrative.

[0036] Fig. 2 To illustrate the operation of the depicted double sensors, the time courses 22 and 24 of signals from the two sensor elements A1 and A2 of the double switch A are shown in a highly schematic form, thus forming a diagram of the response of the two sensor elements. Fig. 1 when a metallic train wheel passes by. "Signal waveform" here refers to the change of a specific measured quantity over time, and accordingly, time in an arbitrary unit is plotted on the abscissa. Above this, signal waveforms 22 and 24 are shown dimensionless and superimposed for easier understanding. In reality, if the sensor elements are resonant circuit coils, the measured quantity could be, for example, a current through the respective coil, which then does not, as in Fig. 2 The curve shown does not show a strictly rectangular slope, but rather a sinusoidal one. If this were plotted on the ordinate and the coils had the same quiescent current, curves 22 and 24 would overlap and be only offset in time. However, the steepness of the slope is not relevant for understanding the figure.

[0037] A self in Fig. 1 An object moving from left to right, e.g., a bicycle, enters the Fig. 2 At time T1 shown, the object enters the detection range of sensor element A1, causing the signal waveform 22 to change. If the object then continues to move, it enters the detection range of the second sensor element A2 at time T2, which also changes the signal waveform 24. As shown, the detection ranges of the sensor elements are arranged so that they overlap spatially, and thus there are also temporal overlap ranges for objects moving in one direction, in particular an overlap range 26 in which the object is detected by both sensor elements simultaneously, while in time range 28 it is detected only by the first sensor element, and in time range 30 only by the second sensor element. The signal waveforms can be evaluated in a known manner to generate counting pulses, but also to measure speed. For axle counting, i.e., for monitoring a track section, the following is usually done as in Fig. 3 The procedure was described.

[0038] The Fig. 3 The diagram shows a highly schematic representation of a first arrangement according to the state of the art for monitoring a track section, in whose opposite end areas (which are not marked with their own reference symbols here) as in Fig. 1 The figures show two wheel sensors A and B, and C and D, respectively, arranged in each case, with wheel sensors A and B located in one end region and wheel sensors C and D in the other end region. Wheel sensors A, B, C, and D are each configured as dual sensors consisting of two sensor elements A1, A2, B1, B2, C1, C2, D1, D2. For the sake of clarity, the two sensor elements of each dual sensor are shown superimposed in the figure; however, they are actually arranged as shown in the figures. Fig. 1 arranged side by side in the direction of the track. This also applies to the Figuren 4 , 5 und 7 .

[0039] As shown in the schematic representation of Fig. 3 As indicated by the ovals labeled 1oo2, in each dual sensor A, B, C, D, the two respective sensor elements are linked in a 1oo2 architecture; that is, a dual sensor fails whenever one of its two sensor elements fails. The sensor elements A and B, and C and D, located at the two opposite ends of the track section to be monitored, are linked in a 1oo2 architecture to form two axle counter circuits 40 and 42, indicated by the dashed lines. Dual sensors A and C form a first axle counter circuit 40, and dual sensors B and D form a second axle counter circuit 42.

[0040] The two axis counter circuits 40 and 42 are linked in a 2oo2 architecture, meaning that the monitoring system thus formed functions as long as at least one of the two axis counter circuits 40 and 42 is functioning. If a redundant monitoring design is required, the axis counter circuit configuration shown is usually used because the corresponding evaluation of the sensor signals is easy to handle. However, it has relatively low availability, since no axis counter circuit is available as soon as a single sensor element fails in either axis counter circuit, regardless of where that sensor element is located. For example, if sensor elements A1 and D2 fail, no axis counter circuit is operational in the architecture shown. To remedy this problem, a redundant axis counter circuit configuration as shown in DE 10 2005 048 852 A1, mentioned at the beginning, was implemented. Fig. 4 shown and suggested.

[0041] According to the schematic representation of Fig. 4 are those used to monitor the in Fig. 1 The wheel sensors A, B, C, and D, designed as double sensors with two sensor elements each, provided for the track section shown, are linked together in such a way that each wheel sensor at each end is linked to each wheel sensor in the opposite sensor area to form an axle counting circuit. Thus, it is not only, as shown in Fig. 3 , a first axle counter circuit 40 is formed from wheel sensors A and C, and a second axle counter circuit 42 from wheel sensors B and D; furthermore, a third axle counter circuit 44 is formed from wheel sensors A and D, and a fourth axle counter circuit 46 from wheel sensors B and C, wherein the wheel sensors in each axle counter circuit are interconnected in a 1oo2 architecture. This interconnection advantageously increases the availability of the arrangement, since now wheel sensors provided in opposite end regions in axle counter circuits 40 and 42, or, if the wheel sensors are designed as dual sensors as here, the sensor elements forming the dual sensors, can fail without this occurring as in Fig. 3 If the monitoring fails – for example, if sensor elements A1 and D2 fail – the axle counter circuit 46, formed from wheel sensors B and C, is still available. However, this type of monitoring is extremely complex with regard to signal evaluation, since even monitoring a simple track section, as in the one described in Fig. 1 The track section shown, with two end sections, requires four axle counting circuits to be evaluated. If the monitored track section is a branched track section with three end sections, as is the case with a simple turnout (see...). Fig. 9 If wheel sensors A and B are located in the first end area, wheel sensors C and D in the second end area, and wheel sensors E and F in the third end area, then two axle counter circuits, namely axle counter circuits ACE, ACF, ADE, ADF, BCE, BCF, BDE, and BDF, must already be evaluated. This type of monitoring is impractical for complex track sections such as shunting yards.

[0042] In a first embodiment of the invention, as in Fig. 5 The wheel sensors A, B, C, and D, again designed as double sensors, are shown and, as in the preceding figures, are arranged in opposite end regions 18 and 20 of the track section to be monitored. They are interconnected such that the sensors A and B, and C and D, located in the same end region 18 and 20 respectively, each form an axle counter 50 and 52 in a 2002 architecture. Only these two axle counters 50 and 52 are then connected to each other in a 1002 architecture to form a single axle counter circuit 40. In this embodiment, the wheel sensors A and B, and the wheel sensors C and D, in the respective axle counters 50 and 52 are each connected by means of a voter 54 and a voter 52, respectively.The axle counters 50 and 52 are linked in such a way that, from a signal perspective, it is not apparent to the "outside world" whether each axle counter 50, 52 is designed redundantly, i.e., includes two or more wheel sensors, or whether it is designed non-redundantly, i.e., includes only one wheel sensor. This, as mentioned above, offers significant advantages with regard to cabling and, in particular, with regard to the evaluation of the signals from the axle counters. Thus, to form the axle counter circuit 40 by means of a 1oo2 linkage of the two axle counters 50, 52, the voters 54 and 56 can each be connected via an interface 58 to a potentially existing axle counter unit 60. The voters 54 and 56 can be implemented in a manner known per se by hardware or software. The wheel sensors A, B, C, D of the axle counters 50, 52, which are designed redundantly here, are connected to the respective voters 54, 56 via an interface 58, whereby all interfaces are defined identically.As mentioned above, the interfaces can simply be cables. From the... Fig. 5 For the person skilled in the art, a particular advantage of the invention also arises directly: by using identically defined interfaces 58, existing axle counting systems in which a wheel sensor is currently directly connected to an axle counting unit 60 can be retrofitted, since from the point of view of the axle counting unit 60 it is irrelevant whether it communicates via the interfaces 58 with an axle counting station consisting of one wheel sensor or of several wheel sensors.

[0043] The in Fig. 5 The arrangement shown has the same availability as the one in Fig. 4 The arrangement shown, however, has the significant advantage that only one axle counter (40) needs to be evaluated, instead of four. If the track section is a branched track section with more than two end sections, only one axle counter is added for each end section. Therefore, with a simple turnout, unlike an arrangement according to... Fig. 4 Instead of eight axle counter circuits, only one is evaluated, which significantly simplifies the handling of the monitoring and makes the monitoring arbitrarily scalable.

[0044] Fig. 6 shows an evaluation scheme of the arrangement according to Fig. 5 If one imagines the individual sensor elements A1, A2, ..., D2 as switches, where it doesn't matter whether the switches close or open upon detecting an object, as long as this is handled uniformly, an evaluation scheme results in which the sensor elements of each individual dual sensor are connected in series, but the two wheel sensors in each end area are connected in parallel. As can be seen from the diagram of the Fig. 6 Directly readable, a wheel sensor or, since the wheel sensors are designed as double sensors, one or both of the sensor elements of the respective double sensor can fail in both end areas of the monitored track section without affecting the availability of the evaluation.

[0045] Fig. 7 Figure 1 shows a circuit diagram according to a second embodiment of the invention. Again, two axle counting stations 50 and 52 are formed from the sensor elements A1, A2, B1 and B2 in one end region of the monitored track section and the sensor elements C1, C2, D1 and D2 in the opposite end region of the monitored track section, wherein the sensor elements in each axle counting station are linked to each other by means of a voter 62 or 64 in a 3004 architecture, which increases the availability during the Fig. 5 The arrangement shown is further enhanced, as sensor elements in different dual sensors of the same end area can now fail without causing a failure of the evaluation. For example, sensor elements A1 and B2 can fail, as can sensor elements C2 and D1. Voters 62 and 64 can be implemented in a known manner using hardware or software. Sensor elements A1, A2, B1, and B2 can be connected to voter 62 via interfaces not shown here, and sensor elements C1, C2, D1, and D2 can be connected to voter 64 via interfaces not shown here. The axle counters 50 and 52 thus formed are linked to form the axle counter 40 in a 1oo2 architecture, with the current wiring typically such that voters 62 and 64 are each connected to the axle counter 60 via an interface. Again, all interfaces can be defined identically.

[0046] From the in Fig. 8 This follows directly from the evaluation scheme shown in the second embodiment. If one imagines the individual sensor elements A1, A2, ..., D2 as switches that either open or close when a detectable object is detected—which is irrelevant for the evaluation as long as this is handled consistently—it becomes clear that... Fig. 8 that the evaluation works as long as at least two sensor elements are functioning in each end area of ​​the monitored track section.

[0047] Are the sensor elements as described in Fig. 7 As shown, the individual sensor elements A1, A2, B1, B2 in the first axle counting station 50 and the individual sensor elements C1, C2, D1, D2 in the second axle counting station 52 are preferably arranged such that the individual sensor elements of each axle counting station are spatially offset from each other along the track, which has the advantage that a so-called pendulum swing can be reliably distinguished from a run-over.

[0048] In the Fig. 9 A highly schematic diagram shows a simple turnout, designated as a whole by 66, with six wheel sensors A, B, C, D, E, and F, which, like the wheel sensors shown above, can each be configured as double wheel sensors with two individual sensor elements. The tracks, which of course each consist of two rails, are shown in the highly simplified diagram of the Fig. 9 The diagram is represented by a single common line. Along the track section, in the end section 18, the so-called pointed end of the switch 66, the two wheel sensors A and B are arranged. Along the two track sections at the so-called blunt end of the switch 66, wheel sensors C and D are arranged on one of the track sections in the end section 20, and wheel sensors E and F are arranged on the other track section in the end section 68. Therefore, the track sections between wheel sensors A, B and C, D, and between wheel sensors A, B and E, F, must be monitored to reliably detect whether the switch is clear or occupied, regardless of whether a rail vehicle enters the switch from the pointed or the blunt end. According to the invention, a first axle counter 50 is formed from the two double sensors A and B, a second axle counter 52 from wheel sensors C and D, and a third axle counter 70 from wheel sensors E and F.Axle counting stations 50, 52, and 70 are then used to form an axle counting circuit. If further track sections are added, the number of axle counting stations included in the circuit increases by the number of additional track sections. The wheel sensors, or, if the wheel sensors are designed as dual sensors, the individual sensor elements, can be located in the individual axle counting stations, as shown in [reference to diagram]. Fig. 5 oder Fig. 7 shown linked. REFERENCE MARK LIST

[0049] 10 Track section 12 Sleeper 14 Rail 16 Rail 18 End area 20 End area 22 Time progression 24 Time progression 26 Overlap area 28 Time area 30 Time area 40 Axle counting circuit 42 Axle counting circuit 44 Axle counting circuit 46 Axle counting circuit 50 Axle counting point 52 Axle counting point 54 Voter 56 Voter 58 Interface 60 Axle counting unit 62 Voter 64 Voter 66 Switch 68 End area 70 Axle counting point A Wheel sensor A1 Sensor element A2 Sensor element B Wheel sensor B1 Sensor element B2 Sensor element C Wheel sensor C1 Sensor element C2 Sensor element D Wheel sensor D1 Sensor element D2 Sensor element T1 Time point T2 Time point

Claims

1. A method for monitoring track sections by means of wheel sensors (A, B, C, D, E, F) arranged in mutually opposite end regions (18, 20, 68) of a track section (10) to be monitored, characterized in that axle counting points (50, 52, 70) are formed from the wheel sensors (A, B, C, D, E, F) in the mutually opposite end regions (18, 20, 68), wherein a single axle counting circuit (40) is formed from the axle counting points (50, 52, 70), and wherein at least one of the axle counting points (50, 52, 70) is redundantly configured and comprises two interconnected wheel sensors (A, B, C, D, E, F).

2. A method according to claim 1, characterized in that the two wheel sensors (A, B, C, D, E, F) of a redundantly configured axle counting point (50, 52, 70) are interconnected in a 2oo2 architecture to form the respective axle counting point.

3. A method according to claim 1 or 2, characterized in that two dual sensors (A, B, C, D) are used as wheel sensors to form a redundantly configured axle counting point (50, 52), wherein each dual sensor (A, B, C, D) consists of two sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) arranged spatially offset in the track direction, and the two sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) of each dual sensor (A, B, C, D) are interconnected in a 1oo2 architecture.

4. A method according to claim 1 or 2, characterized in that two dual sensors (A, B, C, D) are used as wheel sensors to form a redundantly configured axle counting point (50, 52), wherein each dual sensor (A, B, C, D) consists of two sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) arranged spatially offset in the track direction, and the four sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) of the two dual sensors (A, B, C, D) of a redundantly configured axle counting point (50, 52) are interconnected in a 3oo4 architecture to form the respective axle counting point (50, 52).

5. A method according to claim 4, characterized in that the four sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) provided for forming a redundantly configured axle counting point (50, 52) are arranged spatially offset from one another in the track direction.

6. A method according to any one of claims 3 to 5, characterized in that counting pulses are generated in the redundantly configured axle counting points (50, 52) by means of the two dual sensors (A, B, C, D) when at least two spatially offset sensor elements of the four sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) respond in a temporally offset manner.

7. A method according to any one of claims 1 to 6, wherein the track section to be monitored is a branched track section (66) having more than two end regions and an axle counting point (50, 52, 70) is provided in each end region, characterized in that the axle counting points (50, 52, 70) are interconnected to form a single axle counting circuit.

8. An arrangement for monitoring track sections by means of wheel sensors (A, B, C, D, E, F) arranged in mutually opposite end regions (18, 20, 68) of a track section (10) to be monitored, characterized in that axle counting points (50, 52, 70) are formed from the wheel sensors (A, B, C, D, E, F) in the mutually opposite end regions (18, 20, 68), wherein at least one of the axle counting points (50, 52, 70) is redundantly configured and comprises two interconnected wheel sensors (A, B, C, D, E, F), wherein each redundantly configured axle counting point (50, 52, 70) comprises a respective voter (54, 56, 62, 64) for interconnecting the two respective wheel sensors (A, B, C, D, E, F), and wherein a single axle counting circuit (40) is formed from the axle counting points (50, 52, 70).

9. An arrangement according to claim 8, characterized in that the voters (54, 56) of a redundantly configured axle counting point (50, 52) are configured to interconnect the respective wheel sensors (A, B, C, D) in a 2oo2 architecture.

10. An arrangement according to claim 8 or 9, characterized in that the wheel sensors of a redundantly configured axle counting point (50, 52) are each dual sensors (A, B, C, D), wherein each dual sensor (A, B, C, D) consists of two sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) arranged spatially offset in the track direction, and the two sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) of each dual sensor (A, B, C, D) are interconnected in a 1oo2 architecture.

11. An arrangement according to claim 8 or 9, characterized in that the wheel sensors of a redundantly configured axle counting point (50, 52) are each dual sensors (A, B, C, D), wherein each dual sensor (A, B, C, D) consists of two sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) arranged spatially offset in the track direction, characterized in that the voters (62, 64) of a redundantly configured axle counting point (50, 52) are configured to interconnect the four sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) of the two dual sensors (A, B, C, D) in a 3oo4 architecture to form the respective axle counting point (50, 52).

12. An arrangement according to claim 11, characterized in that the four sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) provided for forming a redundantly configured axle counting point (50, 52) are arranged spatially offset from one another in the track direction.

13. An arrangement according to any one of claims 10 to 12, characterized in that each redundantly configured axle counting point (50, 52) is configured to generate counting pulses by means of the two dual sensors (A, B, C, D) when at least two spatially offset sensor elements of the four sensor elements (A1, A2, B1, B2, C1, C2, D1, D2) respond in a temporally offset manner.

14. An arrangement according to any one of claims 8 to 13, wherein the track section to be monitored is a branched track section (66) having more than two end regions and an axle counting point (50, 52, 70) is provided in each end region (18, 20, 68), wherein all axle counting points (50, 52, 70) are interconnected to form a single axle counting circuit.

15. An arrangement according to any one of claims 8 to 13, characterized in that the voters (54, 56, 62, 64) of redundantly configured axle counting points (50, 52, 70) are connected to an axle counting unit (60) via a respective interface (58) to form the axle counting circuit (40), the wheel sensors (A, B, C, D, E, F) of each redundantly configured axle counting point (50, 52, 70) are connected to the respective voter (54, 56, 62, 64) via a respective interface (58), and all interfaces are identically defined.