Patent ID: 12214815

DESCRIPTION OF THE EMBODIMENTS

The rail vehicle1shown inFIG.1is intended for carrying out track maintenance work on a track system2. For example, it is a tamping machine with various work units3. Shown are a lifting and lining unit and a tamping unit as well as components of a chord measuring system. Other track maintenance machines, measuring trolleys, track renewal trains, material transport wagons and the like are also considered to be rail vehicles within the meaning of the present invention.

A monitoring system4is set up to monitor the track maintenance work; it serves to locate the rail vehicle1at any time. For this purpose, the monitoring system4comprises an optical measuring system5and a radio-based measuring system6. There is also a radio connection between the rail vehicle1and a signal box7.

The rail vehicle1moves on a working track8, next to which an operating track9runs. On the one hand, the rail vehicle1and the moving work units3pose a danger to a person10working on the track8. On the other hand, the operating track9represents a danger zone because other rail vehicles run on it during track maintenance work.

The optical measuring system5comprises a stereo camera system11and an evaluation device12, which are arranged on the rail vehicle1. Two high-speed cameras are used for precise detection at higher speeds. They are particularly sensitive in the infrared range and detect the lateral environment of the track8, which is irradiated with infrared lights. For example, several infrared emitters are arranged around the optics of the two cameras.

Optical reference points13are arranged on the track side. These are retro-reflective measurement markers that are preferably equipped with a QR code. Each measurement marker has a point that can be determined by automatic pattern recognition, for example, a centre of a circle. Markers with redundant image elements are advantageous for efficient pattern recognition.

The reference points13are preferably arranged on masts14of an overhead contact line system. The distance from mast14to mast14in the longitudinal direction of the track is usually 60 m to 80 m. In the transverse direction of the track, the distance is approximately 11 m for a double-track line. The resulting small distances between the reference points13lead to the high accuracy of the two measuring systems5,6compared to a stationary reference system.

The radio-based measuring system6comprises anchor modules15arranged on the rail vehicle1and transponders16attached to several reference points13of the track system2. In this context, it is advantageous if the reference points13of the transponders16correspond to the reference points13of the optical measuring system5. This facilitates a comparison of the measuring data by means of a central system unit17.

The respective anchor module15is a transmitter/receiver unit that transmits and receives radio signals. The transmitted signals are received by the transponders16, filtered, and returned. The respective distance between the anchor modules15and the transponders16is determined via a time difference of arrival (TDOA). The position is subsequently determined by means of trilateration.

The anchor modules15and the transponders16are set up for multilateral signal transmission. A modulation technique with chirp spread spectrum is used, which uses so-called chirp pulses for frequency spreading. The signal transmission is controlled and evaluated by means of a computer unit18. The computer unit18is also set up for locating by means of runtime determination and trilateration. A redundant second computer unit18increases fail-safety.

A chirp pulse is a sinusoidal signal, with the frequency rising or falling continuously over time. A corresponding signal curve is used in signal modulation by means of chirp spread spectrum as an elementary transmit pulse, which represents a symbol. Advantageously, a coding with one bit per symbol is selected for a data stream to be transmitted. This ensures particularly robust signal transmission.

The signal transmission between the anchor modules15and the transponders16occurs as temporal sequence of ascending and descending chirp pulses. The chirp spread spectrum uses a large bandwidth, which is a direct result of the respective chirp pulse. This modulation method is particularly robust against interference due to the Doppler effect, because only the frequency change over the duration of a chirp pulse is of importance. The absolute frequency has no influence on the robustness of the transmission within certain limits.

For the locating of the rail vehicle1, position data of the transponders16are stored in the computer unit18. In a multilateration method, the anchor modules15send out locating signals which are returned filtered by the transponders16. The computer unit18evaluates the locating signals and uses them to determine a current position of the rail vehicle1with cm accuracy in real time.

Each person10working on the track8is equipped with a personal warning device19. It comprises a person-specific transponder16, a mobile radio module20including an antenna, and a warning transmitter21. By means of the multilateration method, these person-specific transponders16can also be located in real time with cm precision. When approaching a danger zone22stored in the monitoring system4, the respective person10is warned immediately and the rail vehicle1is stopped automatically if necessary.

The components of the monitoring system4are explained in detail with reference toFIG.2. The signal box7of a railway infrastructure undertaking (RIU) comprises a transmitting/receiving device23with a mobile radio module20including an antenna. Thus, the radio connection of the rail vehicle1is carried out, for example, by means of GSM-R (Global System for Mobile Communications-Railway) or FRMCS (Future Railway Mobile Communication System), based on LTE (Long Term Evolution) and 5G (fifth generation).

Advantageously, the rail vehicle1is equipped with an automated warning system (AWS)24. This is a signal-controlled warning system (SCWS) with a warning and stop function. An AWS centre25located in the signal box7communicates with the automated warning system24of the rail vehicle1to generate a warning and/or activate the stop function when another rail vehicle is approaching on the operating track9. For this purpose, the AWS centre25is coupled to a railway safety system (ESA)26.

In addition, components of a telematic real-time positioning system (TEPOS) for differential GNSS positioning are located in the signal box7. A TEPOS centre27evaluates position data from a terrestrial radio reference station network28. TEPOS is used for the correction of GNSS data. First, GNSS position data29of the rail vehicle1is generated. For this purpose, a first GNSS receiving device30including GNSS antenna31is arranged on the rail vehicle1. The GNSS position data29is transmitted via the mobile radio module20to the TEPOS centre27and is corrected and transmitted back to the rail vehicle1by means of TEPOS correction data32.

Independently of this, the rail vehicle1comprises a second GNSS receiving device33coupled to the optical measuring system5. This second GNSS receiving device33comprises a GNSS antenna31, a longitudinal measuring device, and a system processor for accurately determining GNSS positions.

The position data detected with it are compared with the measuring results of the optical measuring system5.

In order to further increase the fail-safety of the monitoring system4, it is useful to arrange a third GNSS receiving device34. Here, the position data received by means of a GNSS antenna31is compared with the so-called European Geostationary Navigations Overlay Service (EGNOS). This is a Differential Global Positioning System (DGPS) operated by the European Union (GSA, European Global Navigation Satellite Systems Agency) with numerous ground stations in Europe, North Africa, and the Middle East. Correction signals are received and processed promptly via a mobile radio module20and an internet connection.

The data recorded by the described, redundantly installed real-time locating systems5,6,24,30,33,34, is processed in the central system unit17(central locating, control, and monitoring unit). The central system unit17is constructed, for example, as a powerful industrial computer with various peripheral devices. In a preferred embodiment, a redundant central system unit17is arranged to achieve a very high safety requirement level (safety integrity level 4, SIL4). If a SIL4-evaluated locating system, including a SIL4 train integrity secured from rail vehicle1is used, track vacancy detection is no longer required and all associated infrastructure installations (axle counters, point train control, train movements in block sections, etc.) no longer apply.

The central system unit17continuously monitors the tracks8,9. The redundant systems5,6,24,30,33,34are used to locate the rail vehicle1and the persons10on the tracks8,9with high precision. Track maintenance work may also involve other track-bound objects35. These are, for example, additional track maintenance machines, material cars, or measuring trolleys. These objects35are also equipped with redundantly installed real-time locating systems. As soon as an object35or a person10is located in a danger zone22, a warning is issued via the automatic warning system23,24. In the process, persons10concerned are warned by means of the personal warning device19. If necessary, emergency braking of the rail vehicle1or the other track-bound objects35is also activated.

Furthermore, the central system unit17continuously monitors the three redundant GNSS receiving devices30,33,34. In the event of failure of a GNSS receiving device30,33,34, a warning is automatically issued by the central system unit17. In the event of failure of two GNSS receiving devices30,33,34, a warning where acknowledgement is required is issued automatically. In the event of failure of all three GNSS receiving devices30,33,34, a continuous alarm where acknowledgement is required occurs. In addition, the rail vehicle1is stopped.

Another function of the central system unit17is the continuous monitoring of the two measuring systems5,6. In the process, the central system unit17references and checks the plausibility of the position data of both measuring systems5,6. If necessary, correction data is generated, which is transmitted to the three redundant GNSS receiving devices30,33,34. In the event of failure of a measuring system5,6, the central system unit17automatically issues a warning where acknowledgement is required. In the event of failure of both measuring systems5,6, a continuous alarm where acknowledgement is required is issued automatically.

An interface36connects the central system unit17with various input and output systems for operating staff (machine operators, drivers, look-outs, etc.). These input and output systems perform the following functions:Input and output for programming, data retrieval, parameter setting, and operation of the central system unit17,Input and output of acoustic and optical alarms and warnings, status displays of the three GNSS receiving devices,Status indicators of the automatic warning system24including personal warning devices19,Position indicators of the rail vehicle1, andPosition indicators of persons10with personal warning devices19.

In addition, a network connection37(TCP/IP connection) is set up for ongoing status monitoring of the dual central system unit17and the various peripheral devices. Via this network connection37, the described functions of the rail vehicle1can also be called up or influenced via remote access with the corresponding authorisation.

An advantageous embodiment of the radio-based measuring system6is shown inFIG.3. With the arrangement shown of at least eight anchor modules15on the rail vehicle1, a high level of fail-safety is ensured. This is because it ensures that at least two anchor modules15locate the transponders16mounted on the masts14and the transponders16carried by the persons10. The locating signals of vehicle1are indicated with thin dotted lines. The thick dotted lines show the locating signals of the persons10.

In an advantageous further development, each transponder16transmits a digital code as a recognition signal. These codes are stored in the central system unit17and linked to coordinates within a track network. This means that locating within the track network is possible with the radio-based measuring system6alone.

In addition or as an alternative, each reference point13has an optical code. For example, a QR code is integrated in a measurement marker defined as a reference point13. The stereo camera system11then detects the QR code together with the reference point13. The QR code is in turn stored in the central system unit17and is linked to coordinates of the track network.

Advantageously, an integrated reference unit38is arranged on each mast14. This comprises one of the transponders16and defines a reference point13for the radio-based measuring system6. The optical marker together with the QR code is arranged on a housing of the transponder16, wherein the optical reference point13coincides with the reference point13of the radio-based measuring system6.

The respective personal warning device19is also usefully designed as an integrated unit. The transponder16and the mobile radio module20are housed in a common housing. In addition, an acoustic, optical, and/or haptic warning transmitter is arranged. The transponder16is used to locate the corresponding person10. In the event of a danger occurring, the automatic warning system24,25sends a warning message via the mobile radio module20and the warning transmitters21are activated.