The invention relates to a vehicle-based device for a vehicle, in particular a rail vehicle, said device comprising a receiving device which, when passing a track-based transmission device, is suitable for receiving a transmission signal, which is at least also frequency-modulated, from said track-based transmission device.
As is known, in railway installations transponder devices are used to transmit information from the track to the vehicle. The information to be transmitted can, for example, identify the respective transponder, specify its location, or describe signal states and/or properties of the track being passed over.
For example, the so-called Eurobalise is known for locating rail vehicles. The Eurobalise is a passive balise which, upon the approach of a rail vehicle, is put into operation by means of energy transmitted electromagnetically at 27 MHz and transmits a position signal frequency-modulated at frequencies of 3.95 MHz or 4.52 MHz, enabling the positioning of a passing rail vehicle. The position signal contains coding which identifies the balise so that the vehicle, which knows the positions of balises laid in the route network, can determine its own position.
The object underlying the invention is to specify a vehicle-based device which can detect crosstalk of a transmission signal from a track-based transmission device.
This object is achieved according to the invention by a vehicle-based device with the features as claimed in claim 1. Advantageous embodiments of the device according to the invention are specified in subclaims.
According to the invention, it is provided that the vehicle-based device has an evaluation device which is suitable for generating a crosstalk warning, namely depending on the signal levels at different frequencies of the frequency-modulated transmission signal received and/or the frequency curve.
A major advantage of the device according to the invention can be seen in that it can reliably generate a crosstalk warning if there is a certain probability of crosstalk of a transmission signal from an “inaccurate” track-based transmission device—that is to say, from a device whose transmission signal cannot be evaluated. Namely, the inventor determined that in terms of frequency a crosstalk warning can be generated particularly easily, but nevertheless very reliably; accordingly, it is provided according to the invention that the crosstalk warning is generated as a function of signal levels of different frequencies or as a function of the frequency curve.
The track-based transmission device is preferably a transponder device or a component of a transponder device. In this case, it is advantageous if the vehicle-based device has a vehicle-based transmission device which is suitable for transmitting an activation signal for activating the transponder device. In this case, the evaluation device can detect crosstalk of a frequency-modulated transmission signal or response signal from track-based transponder devices which have not been activated by their own vehicle but by another vehicle.
It is advantageous if the evaluation device evaluates the frequency curve and/or the signal levels at different frequencies of the received transmission signal and generates the crosstalk warning if the frequency curve and/or the signal levels indicate a response signal from a transponder device which has been activated by a transmission device other than that of their own vehicle-based device, whether it be a transmission device of another vehicle-based device of their own vehicle or another transmission device of another vehicle.
The evaluation device is preferably designed such that it compares the signal level at a signal frequency of the frequency-modulated transmission signal with the signal level at another signal frequency of the frequency-modulated transmission signal and generates the crosstalk warning if the signal level deviates beyond a predefined degree.
The frequency-modulated transmission signal is preferably a binary signal having a first signal frequency at a logical “0” and a second signal frequency at a logical “1”. It is also advantageous if the signal amplitudes at the two signal frequencies are the same size or at least approximately (±10%) the same size.
It is particularly advantageous if the evaluation device is designed such that it compares the signal level at a signal frequency, in particular the aforementioned first signal frequency, with the signal level at another signal frequency, in particular the aforementioned second signal frequency, and generates the crosstalk warning if the signal level difference reaches or exceeds a predefined threshold or is outside a predefined set point differential range.
Alternatively or additionally, but just as advantageously, it can be provided that the evaluation device is designed such that it generates the crosstalk warning if the edge steepness of the frequency curve falls below a predefined degree over time during signal frequency changes.
In the latter variant, the evaluation device is preferably designed such that it measures the edge steepness of the signal frequency during signal frequency changes and generates the crosstalk warning if the amount of edge steepness reaches or falls below a predefined threshold.
The vehicle-based device is preferably suitable for activating balises of the ETCS standard (European Train Control System) and processing response signals from balises of the ETCS standard.
Furthermore, the invention relates to a vehicle, in particular a rail vehicle. According to the invention, it is provided that this vehicle is equipped with a vehicle-based device, as described above.
Furthermore, the invention relates to a method for transmitting at least one item of information from a track-based transmission device to a passing vehicle, wherein, in the method, the track-based transmission device transmits a track-based transmission signal which is at least also frequency-modulated.
According to the invention, it is provided that there is vehicle-based evaluation of the signal levels at different frequencies of the received transmission signal and/or of the frequency curve of the received transmission signal and a crosstalk warning (UW) is or is not generated depending on the frequency curve and/or signal levels.
With regard to the advantages of the method according to the invention, reference is made to the above statements in connection with the vehicle-based device according to the invention.
The frequency-modulated transmission signal is preferably a binary signal having a first signal frequency at a logical “0” and a second signal frequency at a logical “1”.
It is advantageous if the signal level at the first signal frequency is compared with the signal level at the second signal frequency and the crosstalk warning is generated if the signal level difference reaches or exceeds a predefined threshold.
Alternatively or additionally, it is considered advantageous if the edge steepness of the signal frequency is detected during signal frequency changes from the first signal frequency to the second signal frequency and/or from the second signal frequency to the first signal frequency and the crosstalk warning is generated if the edge steepness falls below a predefined degree.
In a particularly preferred embodiment, it is provided that the signal level at the first signal frequency, the signal level at the second signal frequency and the edge steepness of the signal frequency during signal frequency changes from the first signal frequency to the second signal frequency and from the second signal frequency to the first signal frequency is detected and the crosstalk warning is generated if the signal level at the first signal frequency deviates from the signal level at the second signal frequency beyond a predefined degree or the edge steepness of the signal frequency falls below a predefined degree during signal frequency changes.
The track-based transmission device is preferably a track-based transponder device or a component of a track-based transponder device, in particular a track-based balise. In this case, it is advantageous if a vehicle-based transmission device transmits an activation signal to activate the track-based transponder device and, after receiving the activation signal, the track-based transponder device transmits a response signal, which is at least also frequency-modulated, as the track-based transmission signal.
The invention is explained in more detail hereinafter with reference to exemplary embodiments; in the figures, by way of example,
For the sake of clarity, the same reference characters are always used for identical or comparable components in the figures.
The two rail vehicles 11 and 12 are each equipped with a vehicle-based device 100 comprising a transmission device 110, a receiving device 120 and an evaluation device 130. Hereinafter, it is assumed by way of example that the two vehicle-based devices 100 of the two rail vehicles 11 and 12 are structurally identical or at least both can operate according to the methods described below by way of example.
The vehicle-based devices 100 of the two rail vehicles 11 and 12 are each designed in such a way that their transmission devices 110 transmit or are at least capable of transmitting an activation signal S for activating track-based transponder devices permanently or at least while traveling over the track system 20. For reasons of clarity, in the illustration in accordance with
Hereinafter, it is assumed by way of example that the track-based transponder device 30 is a transponder device which, if an activation signal S is received, transmits a frequency-modulated or at least also frequency-modulated response signal AS. The response signal AS is preferably a binary signal which has a first signal frequency f1 of, for example, between 3.9 MHz and 4.0 MHz (for example, 3.95 MHz) at a logical “0” and a second signal frequency f2 of, for example, between 4.5 MHz and 4.6 MHz (for example, 4.52 MHz) at a logical “1”. The amplitudes at the first signal frequency f1 and the second signal frequency f2 are preferably the same size or preferably only differ within a range of at most ±10%.
The track-based transponder device 30 can be, for example, a balise which operates according to the ETCS (European Train Control System) standard and is accordingly able to output a response signal AS according to the ETCS standard after activation by an activation signal S.
In the illustration in accordance with
In the illustration in accordance with
The evaluation devices 130 of the vehicle-based devices 100 of the two rail vehicles 11 and 12 are preferably designed in such a way that they can detect crosstalk of a response signal AS from a transponder device 30 over which the respective rail vehicle is not currently traveling as reliably as possible. The evaluation devices 130 are preferably suitable for detecting crosstalk based on the signal levels of the response signal AS at different frequencies of the received response signal and/or the frequency curve of the received response signal AS. This will be explained in more detail hereinafter by way of example in connection with
The evaluation device 130 in accordance with
The amplitude measuring device 200 can, for example, operate numerically and have a sampling unit on the input side which samples the response signal AS. The sample values can be subjected to a Fourier transform by means of which the sample values are transformed into the frequency range. The amplitude measuring device 200 can then determine the amplitude of the response signal AS at the first signal frequency f1 of the binary response signal AS and the second signal frequency f2 of the binary response signal AS.
In the case of an undisturbed response signal AS, the amplitudes A(f1) and A(f2) at the two signal frequencies f1 and f2 will be the same size or at least approximately the same size, whereas in the case of a disturbance or resonance, in particular a series resonance through a conductor 21, as shown in
Arranged downstream of the amplitude measuring device 200 in the evaluation device 130 in accordance with
For example, the comparison device 210 can subtract the two signal levels or amplitudes from one another, forming a signal level difference, and compare the signal level difference:
|A(f1)−A(f2)|>SW?
and generate the crosstalk warning UW if a predefined threshold SW is reached or exceeded.
If the comparison device 210 determines that the signal level difference does not reach or exceed the predefined threshold SW, then it can either generate no signal at all on the output side or instead, an output signal OK, which indicates that no crosstalk warning is to be generated.
As a result of the difference formation provided in the embodiment variant in accordance with
The frequency curve measuring device 300 can, for example, operate numerically and have a sampling unit on the input side which samples the response signal AS. The sample values can be subjected to a Fourier transform which transforms the sample values into the frequency range. After such a Fourier transform, the frequency curve f can be determined over time t, as shown by way of example in
In comparison,
After the Fourier transform of the response signal AS into the frequency range, the frequency curve measuring device 300 will measure the edge steepness during signal frequency changes and output corresponding edge steepness values df/dt.
The edge steepness values df/dt reach the comparison device 310 which compares said values to a predefined edge steepness threshold dfmin and outputs a crosstalk warning UW on the output side if the edge steepness values df/dt do not reach or do not exceed the edge steepness threshold dfmin in the event of edges or signal frequency changes.
If the edge steepness threshold dfmin is exceeded or reached, the comparison device 310 will either not output any warning or any signal or instead output an output signal OK, which indicates that a crosstalk warning is not to be output.
The upper branch of the evaluation device 130 in
The lower branch of the evaluation device 130 in
The OR gate 400 generates a crosstalk warning UW on the output side in the form of a logical “1” if at least one of the two auxiliary signals H1 or H2 has a logical “1” on the input side.
If neither the first auxiliary signal H1 nor the second auxiliary signal H2 has a logical “1”, the OR gate 400 generates an output signal OK in the form of a logical “0”, which indicates that there is no crosstalk.
Although the invention has been illustrated and described in more detail by preferred exemplary embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by a person skilled in the art without departing from the scope of the invention.
Number | Date | Country | Kind |
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10 2017 219 644.0 | Nov 2017 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/077252 | 10/8/2018 | WO | 00 |