EP4079598A1

EP4079598A1 - Pathway detection of a light rail vehicle ahead a turnout without detecting the turnout position

Info

Publication number: EP4079598A1
Application number: EP21169286.8A
Authority: EP
Inventors: Gábor Nagy
Original assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH
Current assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH
Priority date: 2021-04-20
Filing date: 2021-04-20
Publication date: 2022-10-26

Abstract

The present invention relates to a method for anticipating a pathway (3) of a light rail vehicle (1) ahead of a turnout (2) by excluding pathways (3) of possible pathways (3) by inspecting flangeways (6) of the possible pathways with detection means (8) and determining the possible pathway if the flangeways (6) continue throughout the turnout (2), and/or determining the anticipated pathway (3) if the speed of the vehicle (1) is higher than an allowed speed of a possible pathway (3).

Description

The present invention refers to a method for anticipating a pathway of a light rail vehicle ahead of a turnout. Further, the present invention also refers to a light rail vehicle adapted to execute the method steps.
In the rail transport sector, safety is granted by wayside safety systems and the exclusivity of usage the rails. To road vehicles, pedestrians and other non-rail-traffic participants, access to railway infrastructure is restricted and kept to a minimum possible. In case of light rail vehicles, especially trams, rail users and road users share the same environment. Railway safety systems do not cover all dangers of collision and drivers are driving on sight and are fully responsible for avoiding a collision.
A driver assistance system for a rail vehicle can be set up, for example, to use a signalling device to warn a vehicle driver of an impending collision of the rail vehicle with an object and / or with a person. In addition, the driver assistance system can optionally be set up to intervene autonomously or partially autonomously in the vehicle control of the rail vehicle, e.g. to brake the rail vehicle before an impending collision.
However, it is disadvantageous if the driver assistance system issues a false warning due to a falsely predicted collision and / or intervenes unnecessarily in the vehicle control, since this can in particular worsen driving comfort for the vehicle occupants, e.g. by unnecessary and possibly strong braking. Strong braking of the rail vehicle could even pose a risk of accident for the vehicle occupants.
Prior art US 2004/0073342 A1 relates to a method and system for ensuring that a train does not pass a device such as a grade crossing gate or a track switch when that device is not properly configured.
US 2014/0247356 A1 discloses a method and system for determining track availability for a railway vehicle. The availability thereby is checked via images captured by a camera of the railway vehicle.
The problem to be solved by the present invention is to provide a method for anticipating a pathway of a light rail vehicle so that false collision warnings based on false anticipated pathways can be reduced.
The aforementioned problem is solved by a method for anticipating a pathway of a light rail vehicle having the features of claim 1 and a light rail vehicle having the features of claim 10. Preferred embodiments of the present invention are specified in the dependent claims.
The present invention specifies a method for anticipating a pathway of a light rail vehicle ahead of a turnout by excluding pathways of possible pathways by inspecting flangeways of the possible pathways with detection means and determining the possible pathway if the flangeways continue throughout the turnout, and/or determining the anticipated pathway if the speed of the vehicle is higher than an allowed speed of a possible pathway.
The anticipated pathway thereby is the pathway, which results from the method steps. In other words, the light rail vehicle with the highest possibility will use this pathway after the turnout. The flangeways are thereby an inner sideportion of the rails which permits a passage of the wheel flanges of the light rail vehicle. By means of the flangeways it is directly derivable how the pathway continue after the turnout so that an anticipated pathway can be derived. The flangeways thereby preferably are detected by a detecting means like a camera, a LIDAR or a radar device. The detection of the flangeways has the advantage that the pathway is easily derivable.
However, it may be possible that the flangeway is not fully detectable by the detection means. This can be the case if the turnout for example is covered by snow or if the light train vehicle stops in front of the turnout. As the driver later on may switch the turnout the pathway cannot be determined. A further indication is the speed of the vehicle. It thereby is assumed that the driver is driving the vehicle on a proper speed for the pathway. This means that with this method step it is possible to derive the anticipated pathway on the basis of the speed. A possible pathway thereby can be excluded if the speed of the light rail vehicle is higher than the speed allowed on this pathway.
According to the invention, this speed preferably corresponds to the actual speed of the light rail vehicle or an anticipated speed when crossing the turnout. The anticipated speed is calculated based on the actual speed before the turnout and the current acceleration/deceleration of the light rail vehicle. Accordingly, it is possible to achieve a result for the anticipated pathway having a high accuracy. False collision warnings based on a wrong pathway are avoided.
In a preferred embodiment of the present invention, the allowed speed on a possible pathway is determined on the basis of drive signals for this pathway. As the light train vehicle also drives on the road so that also traffic lights are relevant for the light train vehicle also these signals are drive signals according to the present invention. The drive signals shows a speed limit for a respective pathway. A speed limit for a respective pathway for example also could be 0 km/h so that it is currently not allowed to drive on a respective pathway. A speed limit for a pathway therefore can be derived from the drive signals.
In a further preferred embodiment, the allowed speed on a possible pathway is determined on the basis of the geometry of the rails on this pathway. The geometry of the rails thereby relates to the radius of a curve after the turnout for example. The speed limit is given on the basis of the centripedal force allowed for the passengers. Further, the speed limit in a respective curve also can be given by the regulation for the railway network. Accordingly, the pathway can be determined in this way that if one pathway has a straight shape and the other pathway is a curve and the driver does not lower the speed to an allowed speed, it can be assumed that the anticipated pathway is the straight route. Accordingly, the anticipated pathway can be easily determined.
According to another embodiment the geometry of the rails are visually detected. The geometry is preferable detected by the camera of the detection means. With this camera it can be easily derived whether one pathway comprises of or continues with a curve in or after the turnout.
In a further embodiment, the geometry of the rails is derived from data of the railway track. The advantage therefrom is that the geometry of the rails also can be determined if the track is not clearly visible e.g. during misty weather or in the dark. Accordingly, the geometry can be determined in each case and for far distances.
According to a preferred embodiment of the invention data of the railway track are derived by simultaneous localization and mapping. The simultaneous localization and mapping (SLAM) is a method in which an ego vehicle simultaneously is constructing a map of an unknown environment and localizes itself in this map. The environment thereby is detected on the basis of various sensors. Accordingly, with this method it is possible to determine the position in a self-constructed map.
Further, in a preferred embodiment it is also possible to derive the data of the railway track by a global navigation satellite system in combination with a database. The global navigation satellite system (GNSS) is not restricted to GPS but also could be for example Galileo, Glonass or Beidou. By means of the GNSS the local position can be determined. In combination with data of a database to the respective position the data of the railway track can be easily derived.
A specific embodiment specifies that the determined anticipated pathway is continuously transmitted to a collision avoidance system. By doing so, the collision avoidance system very early gets the anticipated pathway so that objects on this pathway can be detected very early. Although, it might be possible that the anticipated pathway may change e.g. due to a switched turnout, this change of the pathway is early transmitted to the collision avoidance system so that respective measures could be carried out in order to avoid a collision.
Preferably, the method steps are conducted when visual contact to detectable items is possible. According to the invention a detectable item is an item like the point blades, the turnout position signal, the drive signal or traffic signs, which can be detected by the detection means in order to determine the anticipated pathway. With these detectable items it is possible to determine an anticipated pathway very early. Further, by these items it is recognized that a turnout is ahead of the light rail vehicle.
The invention further specifies a light rail vehicle comprising a visual detecting means and a processing unit, which is designed to conduct the method steps according to the present invention. The processing unit is also designed to evaluate all the data recorded during the method steps. Accordingly, the light rail vehicle has the same advantages as described above for the method.
Preferred embodiments of the invention are shown in the figures and are explained in detail in the following description. The figures showing:

Figure 1: Light rail vehicle ahead of a turnout which is switched to a left pathway,
Figure 2: Light rail vehicle ahead of a turnout which is switched to a right pathway, and

In figure 1 a light rail vehicle 1 is shown which is ahead of a turnout 2 switched to a left pathway 3. The turnout 2 splits the actual way into two pathways 3. In order to direct the light rail vehicle 1 on the respective pathway 3, point blades 4 of the turnout 2 are moved so that these point blades 4 are in contact with an outer rail 5 of the other pathway 3. Thereby this pathway 3 and a respective flangeway 6 is blocked. In figure 1 the point blades 4 are in contact with the right side rail 5. The light rail vehicle 1 therefore will continue on the left pathway 3.
Next to the rails 5 there are drive signals 7 which are used when the train driver is driving on sight. These drive signals 7 are separately provided for each direction and indicates whether the light rail vehicle 1 has to stop or can drive.
The light rail vehicle 1 comprises a detection means 8 like a camera and/or a LIDAR for inspecting the flangeways 6 and the drive signals 7. The respective information is forwarded to a processing unit 9, which evaluates this data in order to determine an anticipated pathway 3. In this processing unit 9 it is determined, whether the flangeway 6 is continuously visible throughout the turnout 2 and which flangeway 6 is not blocked by for example the point blades 4. From this information, the anticipated pathway 3 can be derived.
However, the flangeways 6 may be not visible at the position of the point blades 4 due to the light rail vehicle 1 obstructing the view for the detection means 8. In this case the processing unit 9 derives an allowable speed from the drive signal 7 or from a curve radius. If the actual speed of the vehicle is higher than a speed allowed on a possible pathway this pathway could be excluded to determine the anticipated pathway 3.
This pathway 3 is transmitted to the collision avoidance system 10. From the data of the camera and the LIDAR, the collision avoidance system 10 recognize that an object 11 is on the anticipated pathway 3. In order to avoid a collision the train driver could be warned and/or a horn could be activated. If the train driver does not react, the collision avoidance system 10 also could conduct an emergency stop of the light rail vehicle 1.
Figure 2 shows the light rail vehicle 1 ahead of a turnout 2 which is switched to a right pathway 3. In contrast to figure 1, the point blades 4 are in contact with the outer rail 5 of the left side so that the flangeways 6 continues on the straight track. After the turnout 2, the light rail vehicle 1 therefore will drive on the right pathway 3. However, on this pathway 3 no object 11 is on the track. In this figure, the object 11 is on the left pathway 3. In order to avoid a false warning of the collision avoidance system 10 the method for anticipating the pathway 3 of the light rail vehicle 1 is proposed.

REFERENCE SIGNS

1: light rail vehicle
2: turnout
3: pathway
4: point blades
5: rail
6: flangeway
7: drive signal
8: detection means
9: processing unit
10: collision avoidance system
11: object

Claims

Method for anticipating a pathway (3) of a light rail vehicle (1) ahead of a turnout (2) by excluding pathways (3) of possible pathways (3) by inspecting flangeways (6) of the possible pathways with detection means (8) and determining the possible pathway if the flangeways (6) continue throughout the turnout (2), and/or determining the anticipated pathway (3) if the speed of the vehicle (1) is higher than an allowed speed of a possible pathway (3).
Method according to claim 1, characterized in that the allowed speed on a possible pathway (3) is determined on the basis of drive signals (7) for this pathway (3).
Method according to claim 1 or 2, characterized in that the allowed speed on a possible pathway (3) is determined on the basis of the geometry of the rails (5) on this pathway (3).
Method according to claim 3, characterized in that the geometry of the rails (5) are visually detected.
Method according to claim 3 or 4, characterized in that the geometry of the rails (5) are derived from data of the railway track.
Method according to claim 5, characterized in that data of the railway track are derived by simultaneous localization and mapping or are derived by a global navigation satellite system in combination with a database.
Method according to one of the preceding claims, characterized in that the determined anticipated pathway (3) is continuously transmitted to a collision avoidance system (10).
Method according to claim 7, characterized in that if an object (11) is on the anticipated pathway (3) that is on a collision course with the vehicle (1), the collision avoiding system (10) is conducting actions in order to avoid the collision.
Method according to one of the preceding claims, characterized in that the method steps are conducted when visual contact to detectable items (7) is possible.
Light rail vehicle (1), comprising a visual detecting means (8) and a processing unit (9), which is designed to conduct the method steps according to one of the preceding claims.