Method and monitoring system for determining the position of a rail vehicle

Abstract

The present invention relates to a method for determining the position of a rail vehicle (1) moving on a track (8) by means of an optical measurement system (5) including a stereo camera system (11) and an evaluation device (12), in which the stereo camera system (11) captures image pairs of reference points (13) around the lateral periphery of the track (8), and the position of the rail vehicle (1) relative to the reference points (13) is determined by photogrammetry. The position of the rail vehicle (1) is additionally detected by a radio-based measurement system (6) that uses anchor modules (15) attached to the rail vehicle (1) and transponders (16) attached to the reference points (13) to determine its position in real time, with the position data of both measurement systems (5, 6) being collated by a system center (17). In this way, two independent measurement systems (5, 6) are used to generate the position data.

Description

[Technical Field]

[0001] The present invention relates to a method for determining the position of a rail vehicle moving on a track by means of an optical measurement system including a stereo camera system and an evaluation device, in which the stereo camera system takes image pairs of reference points on the lateral periphery of the track and the position of the rail vehicle relative to the reference points is determined by photogrammetry. The present invention also relates to a monitoring system for carrying out this method. [Background technology]

[0002] Railway facilities are subject to numerous safety regulations. This applies in particular to maintenance of track facilities or track construction work. In particular, rail vehicles operated as track construction machines must be continuously located in order to enable early identification of dangerous situations. To meet this requirement, various devices and methods are known, ranging from those integrated into the track to the use of global navigation satellite systems (GNSS). German Patent Application No. 10 2015 207 223 A1 discloses a solution for locating rail vehicles by train control and train safety systems.

[0003] Austrian Patent Application Publication No. 518579 discloses a precise measuring system for determining positions during track construction. This solution is used, on the one hand, to determine the current track position with millimeter accuracy. This, in turn, allows for the positioning of a track vehicle equipped with the measuring system. Specifically, this measuring system is used to verify the measurements of an inertial measurement unit and a path sensor in a fixed reference system. For this purpose, reference points located on the side of the track are photographed by a stereo camera system and their positions are determined. Conventional marking bolts attached to fixed structures, such as utility poles, are used as reference points. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention is based on the object of improving the method of the type mentioned at the beginning in such a way that a high degree of reliability is achieved when locating rail vehicles, and also to provide a monitoring system that allows reliable and robust locating of rail vehicles. [Means for solving the problem]

[0005] According to the invention, these problems are solved by a method according to claim 1 and a monitoring system according to claim 7. The dependent claims describe advantageous embodiments of the invention.

[0006] In this case, the position of the rail vehicle is additionally detected by a radio-based measurement system that uses anchor modules attached to the rail vehicle and transponders attached to multiple reference points to determine its position in real time, with the position data from both measurement systems being collated by a system center. In this way, two independent measurement systems are used to generate position data. The collation of these position data ensures particularly reliable location of the rail vehicle. Even if one system fails, the rail vehicle can still be located, thereby meeting high safety requirements.

[0007] An advantageous development of the invention proposes that a multilateration signal transmission is performed between the anchor module and the transponder by chirp spread spectrum. The modulation technique used for the so-called chirp pulse spread spectrum is called Chirp Spread Spectrum (CSS). The corresponding modulation method is standardized in the IEEE 802.15.4a standard. Signal modulation using chirp spread spectrum avoids the risk of signal corruption that may be caused, for example, by jamming or spoofing of GNSS signals.

[0008] A further improvement proposes that the optical code detected together with the reference point is evaluated to determine the position data within the track network. This is, for example, a QR code, which contains information about the position of the reference point within the track network. Due to their robustness, such optical codes are particularly suitable for use in track construction.

[0009] Additionally, it is advantageous if at least one of the transponders transmits a digital code that identifies its position data within the rail network. In this way, rail vehicles can be located within the rail network solely through the radio-based measurement system. It is advantageous to provide various redundancies to maintain system safety in the event of a radio connection failure. For example, more transponders and anchor modules with position data are installed than would be required for fault-free location.

[0010] According to an advantageous development of the invention, the current position of a person working on the track and equipped with a personally associated transponder is detected by a radio-based measurement system. Thus, the position of the person working on the track is known at any time. The corresponding position data is used to generate an automated alarm in the event of a danger.

[0011] In this case, it is advantageous if the transponders associated with individuals are continuously evaluated for their presence within a danger zone, and an alarm signal is sent if a person is present within the danger zone where a dangerous situation is occurring, such as from the approach of a rail vehicle on a work track. Furthermore, the position data of the person can be compared with the position data of an approaching rail vehicle on an adjacent track. If an approach occurs, an alarm associated with the person is issued, thereby eliminating the need for a general-purpose work crew alarm system with audible and visual alarm generators.

[0012] A monitoring system according to the present invention for implementing one of the methods described above includes reference points positioned on the lateral periphery of a railway track and a rail vehicle capable of traveling on the track, the rail vehicle being equipped with an optical measurement system for detecting the position of the rail vehicle relative to the reference points, and additionally a radio-based measurement system for real-time location determination by means of anchor modules attached to the rail vehicle and transponders attached to the reference points, with both measurement systems being coupled to a system center for cross-checking the position data of both measurement systems.

[0013] In an advantageous development, the system center is coupled to the machine control of the rail vehicle to trigger forced braking in the event of a danger. For this purpose, the system center receives position data from other rail vehicles and from people present on the track. Forced braking is triggered when approaching beyond a threshold or when entering a defined safety zone.

[0014] One proposed improvement to the radio-based measurement system is to provide the anchor module and transponder with a multilateration signal transmission using chirp spread spectrum, with at least one computer unit for evaluating this signal transmission. In this case, redundancy is useful to ensure system failure protection. For example, multiple computer units can be interconnected to form a high-availability cluster. In this way, if one computer unit fails, the radio-based measurement system can continue to provide reliable location determination.

[0015] Preferably, each transponder is provided for periodically transmitting an identification signal, the period of which is adapted to predetermined requirements. A shorter period of time allows the components to respond more quickly. A longer period of time is advantageous for reducing the energy consumption of the transponder.

[0016] The monitoring system is made even more secure against failures if a redundant system center is provided to cross-check the position data of both measuring systems. At least two system centers therefore form a high-availability cluster, which, together with the additionally available optical measuring system, achieves a very high safety requirement level (Safety Integrity Level, SIL).

[0017] A further improvement of the system components is that one reference unit includes one optical measurement marker and one of the transponders. The functions of both measurement systems are integrated into this reference unit. Preferably, each optical reference point coincides with the reference point of the corresponding transponder. This makes it significantly easier to verify the resulting position data.

[0018] A monitoring system can be advantageously developed if the railway workers are equipped with a personal alarm device that includes a transponder associated with the individual and a mobile radio module. This device thus fulfills both the location function and the personal alarm function. For example, a vibrating armband can be used as an alarm generator, which is activated in a dangerous situation via the mobile radio module.

[0019] A further improvement proposes that the tracked vehicle includes at least one GNSS receiver, thereby providing an additional location system that increases the reliability and fault tolerance of the monitoring system.

[0020] For efficient communication between the rail vehicle and external devices, it is advantageous if the rail vehicle is equipped with at least one mobile radio module, which can, for example, enable data communication with an Automatic Warning System (AWS) center, and which can also transmit alarms to the personal alarm devices of people working on the tracks.

[0021] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a schematic diagram of a rail vehicle on a railroad facility. [Figure 2] FIG. 1 shows a schematic block circuit diagram of a monitoring system. [Figure 3] FIG. 1 is a diagram illustrating the components of a wireless-based measurement system. DETAILED DESCRIPTION OF THE INVENTION

[0023] The rail vehicle 1 shown in Figure 1 is prepared for carrying out track construction work on a rail installation 2. This is, for example, a compaction machine equipped with various work implements 3. Lifting and lining equipment is shown, as well as tamping equipment and components of a string measurement system. Other track construction machines, measuring cars, track switching trains, material handling vehicles, etc. are also considered to be rail vehicles within the meaning of the present invention.

[0024] To monitor the track construction work, a monitoring system 4 is provided, by means of which the rail vehicle 1 can be located at any time. For this purpose, the monitoring system 4 comprises an optical measuring system 5 and a radio-based measuring system 6. In addition, a radio connection is established between the rail vehicle 1 and a signal box 7.

[0025] The rail vehicle 1 moves on a work track 8, adjacent to which runs a service track 9. On the one hand, the rail vehicle 1 and the moving work equipment 3 pose a danger to people 10 working on the track 8. On the other hand, the service track 9 forms a danger zone, since other rail vehicles pass on this track during track construction work.

[0026] The optical measurement system 5 comprises a stereo camera system 11 and an evaluation device 12, which are arranged on the track vehicle 1. For accurate detection at relatively high speeds, two high-speed cameras are used. These are particularly sensitive in the infrared range and detect the lateral periphery of the track 8, which is illuminated with infrared light. For example, several infrared emitters are arranged around the optics of both cameras.

[0027] Optical reference points 13 are arranged alongside the track. These are retroreflective measurement markers, which are preferably equipped with a QR code. Each measurement marker has a point that can be identified by automatic pattern recognition, for example the center of a circle. For efficient pattern recognition, markers with redundant pixels are advantageous.

[0028] These reference points 13 are preferably arranged on poles 14 of the overhead line installation. In this case, the distance between the poles 14 in the longitudinal direction of the track is usually 60 to 80 m. In the transverse direction, this distance is approximately 11 m in double-track sections. The distance between the reference points 13 is therefore short, which allows for high accuracy of both measurement systems 5, 6 relative to a fixed reference system.

[0029] The radio-based measurement system 6 includes anchor modules 15 arranged on the track vehicle 1 and transponders 16 attached to a number of reference points 13 on the track infrastructure 2. In this case, it is advantageous if the reference points 13 of the transponders 16 coincide with the reference points 13 of the optical measurement system 5, which facilitates the verification of the measurement data by the system center 17.

[0030] Each anchor module 15 is a transceiver unit that transmits and receives radio signals. The transmitted signals are received, filtered and transmitted back by the transponder 16. Through propagation time determination (Time Difference of Arrival, TDOA), the individual distances between the anchor modules 15 and the transponders 16 are determined. This is followed by trilateration to determine the position.

[0031] In this case, the anchor module 15 and the transponder 16 are provided for multilateration signal transmission. The chirp spread spectrum modulation technique is used, which is used for the so-called chirp pulse spectrum spread. The signal transmission is controlled and evaluated by a computer unit 18. The computer unit 18 is also provided for determining the time of flight and for determining the location by trilateration. A redundant second computer unit 18 provides increased fault protection.

[0032] A chirp pulse is a sinusoidal signal whose frequency continuously increases or decreases over time. The corresponding signal transition is used as the basic transmission pulse for one symbol in signal modulation by chirp spread spectrum. Preferably, for a data stream to be transmitted, a coding with one bit per symbol is selected. In this way, particularly robust signal transmission is ensured.

[0033] Signal transmission between the anchor module 15 and the transponder 16 is carried out as a time-series sequence of ascending and descending chirp pulses. Chirp spread spectrum modulation takes advantage of the wide bandwidth directly caused by the individual chirp pulses. This modulation method is particularly robust against interference caused by the Doppler effect, since only the frequency change of the chirp pulses over time is important. The absolute frequency does not affect the robustness of the transmission within a certain range.

[0034] To locate the rail vehicle 1, the computer unit 18 stores position data from the transponders 16. In the case of multilateration, multiple anchor modules 15 transmit location signals that are filtered and transmitted back by multiple transponders 16. The computer unit 18 evaluates the location signals and thereby determines the current position of the rail vehicle 1 with centimeter accuracy in real time.

[0035] Each person 10 working on the track 8 is equipped with a personal alarm device 19. This device comprises a transponder 16 associated with the person, a mobile radio module 20 with an antenna, and an alarm generator 21. By means of multilateration, these transponders 16 associated with the persons can also be located in real time with centimeter accuracy. Upon approaching a danger zone 22 stored in the monitoring system 4, the individual person 10 is immediately alerted and the track vehicle 1 is optionally automatically stopped.

[0036] The components of the monitoring system 4 are explained in more detail with reference to Fig. 2. The signal box 7 of the railway infrastructure operator (EIU) is equipped with a transceiver 23 having a mobile radio module 20 equipped with an antenna. The radio link of the track vehicle 1 is thus established, for example, by GSM-R (Global System for Mobile Communications - Railway) or FRMCS (Future Railway Mobile Communication System), on the basis of LTE (Long Term Evolution) and 5G (fifth-generation).

[0037] Advantageously, the rail vehicle 1 is equipped with an automatic warning system (AWS) 24, which is a signal-controlled warning system (SCWS) with warning and stopping functions. An AWS center 25 located in the signal box 7 communicates with the automatic warning system 24 of the rail vehicle 1 in order to issue a warning and / or activate a stopping function when another rail vehicle approaches on the operating line 9. For this purpose, the AWS center 25 is coupled to a railway safety installation (ESA) 26.

[0038] Additionally, components of a Telematics Real-Time Positioning System (TEPOS) are located within the signal box 7 for differential GNSS positioning. To do this, a TEPOS center 27 evaluates position data from a terrestrial radio reference station network 28. TEPOS is used to correct the GNSS data. In this case, GNSS position data 29 for the track vehicle 1 are first generated. For this purpose, a first GNSS receiver 30 with a GNSS antenna 31 is located on the track vehicle 1. The GNSS position data 29 is transmitted to the TEPOS center 27 via the mobile radio module 20, corrected using TEPOS correction data 32, and transmitted back to the track vehicle 1.

[0039] Independently, the track vehicle 1 is equipped with a second GNSS receiver 33, which is coupled to the optical measurement system 5. This second GNSS receiver 33 comprises a GNSS antenna 31, a longitudinal measuring device and a system processor for accurate GNSS position determination. The position data thus determined are compared with the measurements of the optical measurement system 5.

[0040] To further increase the fault-proofing of the monitoring system 4, it is useful to install a third GNSS receiver 34. In this case, the position data received by the GNSS antenna 31 is cross-checked by the so-called European Geostationary Navigations Overlay Service (EGNOS). This is the Differential Global Positioning System (DGPS) operated by the European Union (GSA, European Global Navigation Satellite Systems Agency), which has numerous ground stations in Europe, North Africa and the Near East. Correction signals are received and processed in a timely manner via the mobile radio module 20 and an internet connection.

[0041] The data collected by the redundantly configured real-time location systems 5, 6, 24, 30, 33, 34 is processed in a system center 17 (central location, control, and monitoring unit). The system center 17 is configured, for example, as a high-performance industrial computer with various peripheral devices. According to one preferred embodiment, a redundant system center 17 is arranged to achieve a very high level of safety requirements (Safety Integrity Level 4, SIL4). The use of a SIL4-rated location system, including SIL4 train integrity guaranteed on the part of the rail vehicle 1, eliminates the need for track clearance reporting and all associated infrastructure facilities (axle counters, train control at points, train operation in blocks, etc.).

[0042] The system center 17 continuously monitors the tracks 8 and 9. The redundant systems 5, 6, 24, 30, 33, and 34 locate the rail vehicle 1 and any person 10 present on the tracks 8 and 9 with high accuracy. Track construction work can also involve additional objects 35 connected to the tracks, such as additional track construction machinery, material handling vehicles, or measuring vehicles. These objects 35 are also equipped with redundant real-time location systems. As soon as an object 35 or person 10 is located within the danger zone 22, an alarm is issued via the automatic alarm systems 23 and 24. The person 10 in question is then alerted by a personal alarm device 19. Possibly, forced braking of the rail vehicle 1 or other objects 35 connected to the tracks is also initiated.

[0043] Furthermore, the system center 17 continuously monitors the three redundant GNSS receivers 30, 33, 34. If one GNSS receiver 30, 33, 34 fails, an alarm is automatically sent from the system center 17. If two GNSS receivers 30, 33, 34 fail, an alarm is automatically sent, which must be acknowledged. If all three GNSS receivers 30, 33, 34 fail, a continuous alarm, which must be acknowledged, is issued. In addition, the track vehicle 1 is stopped.

[0044] A further function of the system centre 17 is the continuous monitoring of both measurement systems 5, 6. In this case, the system centre 17 references the position data of both measurement systems 5, 6 and performs plausibility checks. If necessary, correction data are generated and transmitted to the three redundant GNSS receivers 30, 33, 34. If one of the measurement systems 5, 6 fails, an alarm with acknowledgement is automatically sent from the system centre 17. If both measurement systems 5, 6 fail, a continuous alarm with acknowledgement is automatically sent.

[0045] The interface 36 connects the system center 17 with various input / output systems for the operators (engineers, drivers, security, etc.), which fulfill the following functions: Input / output for programming, data query, parameter adjustment and operation of the system center 17; Audible and visual alarms and warnings for three GNSS receivers, status display inputs and outputs; status indication of automatic alarm systems 24, including personal alarm devices 19; Position display of rail car 1, and Position representation of person 10 holding personal alarm device 19.

[0046] Additionally, a network terminal (TCP / IP terminal) is provided for continuous status monitoring of the dual system center 17 and various peripheral devices. Via this network terminal 37, the aforementioned functions of the rail car 1 can be called up or controlled, even by remote access, if the appropriate authorization is available.

[0047] An advantageous configuration of the radio-based measurement system 6 is shown in Figure 3. The illustrated arrangement of at least eight anchor modules 15 on the track vehicle 1 provides a high degree of safety against failures. In this way, it is ensured that at least two anchor modules 15 locate the transponders 16 attached to the masts 14 and the transponders 16 carried by the person 10. The locating signal of the vehicle 1 is indicated by a thin dotted line. The locating signal of the person 10 is indicated by a thick dotted line.

[0048] In an advantageous development, each transponder 16 transmits a digital code as an identification signal. These codes are stored in the system center 17 and linked to coordinates within the track network. Thus, location within the track network can be achieved solely by means of the radio-based measurement system 6.

[0049] Additionally or alternatively, each reference point 13 has an optical code. For example, a QR code is incorporated into the measurement marker defined as the reference point 13. In this case, the stereo camera system 11 detects the QR code together with the reference point 13. The QR code is also stored in the system center 17 and is linked to coordinates in the track network.

[0050] Advantageously, one integrated reference unit 38 is arranged on each pole 14. This unit includes one of the transponders 16 and defines the reference point 13 for the radio-based measurement system 6. An optical marker with a QR code is arranged on the housing of the transponder 16, whereby the optical reference point 13 coincides with the reference point 13 of the radio-based measurement system 6.

[0051] The individual personal alarm devices 19 are also usefully formed as integrated units. A transponder 16 and a mobile radio module 20 are housed in a common housing. Additionally, an audible, visual, and / or tactile alarm generator is arranged. The corresponding person 10 is located via the transponder 16. In the event of a danger, automatic alarm systems 24, 25 send an alarm message via the mobile radio module 20, activating the alarm generator 21.

Claims

1. A method for determining the position of a rail vehicle (1) moving on a track (8) by means of an optical measurement system (5) including a stereo camera system (11) and an evaluation device (12), comprising: A method in which the stereo camera system (11) takes pairs of images of reference points (13) around the sides of the track (8) and the position of the rail vehicle (1) relative to the reference points (13) is determined by photogrammetry, Additionally, the position of the track vehicle (1) is detected by a radio-based measurement system (6) for real-time location determination using anchor modules (15) attached to the track vehicle (1), transponders (16) attached to a number of the reference points (13), and a computer unit provided for real-time location determination by time of flight determination and trilateration; The position data of both measuring systems (5, 6) are collated by a system center (17), the radio-based measurement system for detecting the position of the rail vehicle (1) detects the current position of a person (10) working on the track (8, 9) and equipped with a personally associated transponder (16); The method comprises continuously evaluating whether the transponder (16) associated with an individual is within a danger zone (22) and transmitting an alarm signal if the person (10) is within the danger zone (22) where a dangerous situation is occurring.

2. 2. The method according to claim 1, wherein the signal transmission between the anchor module (15) and the transponder (16) is performed in a multilateration manner by chirp spread spectrum.

3. 3. The method according to claim 1, wherein the optical signature detected together with the reference point (13) is evaluated to determine position data within the track network.

4. 4. The method according to claim 1, wherein at least one of the transponders (16) transmits a digital code for identifying position data within the rail network.

5. 10. A monitoring system (4) for carrying out the method according to any one of claims 1 to 4, comprising reference points (13) positioned on the lateral periphery of a track (8) and a track vehicle (1) capable of travelling on said track (8), said track vehicle (1) being provided with an optical measuring system (5) for detecting the position of said track vehicle (1) relative to said reference points (13), Additionally, a radio-based measurement system (6) is provided for real-time localization by means of anchor modules (15) attached to the track vehicle (1), transponders (16) attached to a number of the reference points (13), and a computer unit provided for real-time localization by time of flight determination and trilateration, a system center (17) coupled to both measuring systems (5, 6) for collating position data of both measuring systems (5, 6); A monitoring system (4) characterized in that a person (10) working on the railway (8, 9) is equipped with a personal alarm device (19), the personal alarm device (19) including a transponder (16) associated with the person, the system center (17) continuously evaluates whether the transponder (16) associated with the person is present within a danger zone (22), and an automatic alarm system (23, 24) sends out an alarm signal when the person (10) is present within the danger zone (22) where a dangerous situation is occurring.

6. 6. A monitoring system (4) according to claim 5, wherein the system center (17) is coupled to a mechanical control of the track vehicle (1) for triggering forced braking in case of danger.

7. 7. A monitoring system (4) according to claim 5 or 6, characterized in that the anchor module (15) and the transponder (16) are provided for signal transmission in a multilateration method using chirp spread spectrum, and at least one computer unit (18) is provided for evaluating the signal transmission.

8. 8. A monitoring system (4) according to any one of claims 5 to 7, wherein each transponder (16) is arranged to periodically emit an identification signal.

9. 9. The monitoring system (4) according to claim 5, further comprising a redundant system center (17) for checking the position data of both measuring systems (5, 6).

10. 10. The monitoring system (4) according to any one of claims 5 to 9, wherein one reference unit (38) comprises one optical measurement marker and one of the transponders (16).

11. 11. The monitoring system (4) according to any one of claims 5 to 10, wherein the track vehicle (1) is equipped with at least one GNSS receiving device (30, 33, 34).

12. 12. The monitoring system (4) according to any one of claims 5 to 11, wherein the track vehicle (1) is equipped with at least one mobile radio module (20).

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