Method and system for obstacle identification during and after train coupling

Abstract

A method, a system, and a train control apparatus for the identification of obstacles while an automatically controlled active train approaches a passive train for coupling. At least one first onboard sensor of a first sensor type is used to identify obstacles when the distance between the trains exceeds a predetermined threshold value. At least one second onboard sensor of a second sensor type which differs from the first sensor type is used for the identification of obstacles when the distance is below the predetermined threshold value. The first sensor is ignored for the identification of obstacles when the distance is below the predetermined threshold value. The system includes the first and second sensors, and a train control apparatus which is configured to perform the method. A computer program product has instructions for performing the method.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority, under 35 U.S.C. § 119, of European Patent Application EP25154596.8, filed Jan. 29, 2025; the prior application is herewith incorporated by reference in its entirety.FIELD AND BACKGROUND OF THE INVENTION

[0002] The present invention relates to a method for the identification of obstacles during and after train coupling, a train control apparatus, a system for the identification of obstacles during and after train coupling, and a related computer program product.

[0003] Train control systems are used to control and automate the operation of trains in rail networks. These systems typically assume functions such as speed control, signaling, route management and safety monitoring. With advances in rail technology, train control systems have developed to integrate more complex algorithms and sensors and thus improve efficiency, safety and automation capabilities.

[0004] An important area of development in train control systems is the automated coupling between railcars. Coupling requires precise alignment and connection of two railcars or locomotives, which requires careful monitoring of train movement and identification of obstacles in the coupling area. Traditionally, coupling has been heavily reliant on human operators who monitor the process visually and control the train movements. However, this manual approach has limitations in terms of precision, consistency, and safety.

[0005] The method and system described herein for the identification of obstacles during train coupling can also be used in scenarios in which railcars are positioned in close proximity, without actually being coupled mechanically. This includes situations such as parking trains in a depot or station or positioning a train near a buffer stop at the end of a route. In these cases, the term "coupling" used in this application includes not only the process of mechanical connection of railcars, but also the controlled approach and precise positioning of railcars or trains in relation to one another or to fixed structures, maintaining a safe distance and identifying potential obstacles being crucial in avoiding collisions and ensuring operational efficiency.

[0006] Automated coupling systems aim to improve manual methods by using sensors and control algorithms to manage the coupling process. These systems typically use different types of sensors to identify the relative positions of the railcars and possible obstacles. Common types of sensors include optical sensors, radar, lidar and video cameras. The sensor data is processed by control algorithms to determine suitable train movements for safe and precise coupling.

[0007] However, existing automated coupling systems face multiple technical challenges. A major problem is the difficulty of achieving reliable obstacle identification when there are very short distances between the railcars. Many types of sensors which work well for identification over longer distances become less effective or unreliable in the final stages of coupling when the distance between the cars is very small. This can lead to potential safety risks if obstacles are not identified.

[0008] Furthermore, the passive train with which coupling is to take place is also identified as an obstacle, so that the coupling process is prevented by the control system for avoiding a collision with an obstacle. Even in the event that the sensors for obstacle identification are able to identify the passive train as such due to its size, the identification of another genuine obstacle is typically only possible with difficulty.

[0009] A further challenge is balancing the need for precise distance measurements with robustness in relation to environmental factors such as weather conditions, lighting and track geometry. Sensors which provide highly accurate distance data may be susceptible to interference, while more robust sensors may possibly not have the precision required for final coupling alignment.

[0010] Moreover, there are challenges in the development of control algorithms which are able to switch smoothly between different sensor inputs and coupling phases while at the same time ensuring safety and efficiency. The system must be able to identify reliably when it is necessary to switch between identification methods for longer and shorter ranges.

[0011] It has been recognized that an improved obstacle identification system for train coupling is needed to overcome one or more of these problems.

[0012] European Patent EP 2 537 731 B1 discloses an apparatus for measuring the distance between two public transport vehicles which can be mechanically coupled or uncoupled. The system uses video devices to identify patterns or markings on the vehicles, the geometric features of which alter as the distance between the vehicles changes. This enables the determination of the distance based on the optical resolution of the patterns. However, this system uses only optical sensors, which at very short distances may be associated with disadvantages and possibly fail to identify smaller obstacles between the trains.

[0013] Published patent application US 2010 / 0044998 A1 describes an autonomous rail vehicle with a retractable coupling system for connecting to other vehicles. The system comprises a first coupling part on the front of the vehicle and a second part on the back, allowing vehicles to be coupled to form a train. Means of protection such as gaiters are used to prevent contact between the coupling and external elements. While this system provides a coupling mechanism with intrusion protection for the gap between the coupled train parts, it does not specifically address obstacle identification during the coupling process.

[0014] Published patent application US 2020 / 0189631 A1 discloses an apparatus and a system for monitoring the distance between railway cars during coupling using a distance sensor attached to one car. Based on the distance data, the system can control train movements in order to automate the coupling process. However, this system relies on a single type of distance sensor, which may have limitations in reliability across the entire range of coupling distances.SUMMARY OF THE INVENTION

[0015] Based on the known method for the identification of obstacles during train coupling, the present invention addresses the challenge of providing a reliable and efficient obstacle identification system which can work effectively across the entire range of coupling distances.

[0016] With the above and other objects in view there is provided, in accordance with the invention, a method for identifying obstacles while an automatically controlled active train approaches a passive train for coupling, the method comprising:

[0017] providing at least one first onboard sensor of a first sensor type configured for identifying obstacles between the active train and the passive train when a distance between the active train and the passive train exceeds a predetermined threshold value;

[0018] providing at least one second onboard sensor of a second sensor type which differs from the first sensor type, and using the at least one second sensor for identifying obstacles between the active train and the passive train when the distance between the active train and the passive train lies below the predetermined threshold value; and

[0019] ignoring the first sensor for identifying obstacles when the distance between the active train and the passive train lies below the predetermined threshold value.

[0020] The following paragraphs contain explanatory definitions for the technical terms used in the claims. The specific definitions should not be understood as a restriction of disclosure, but rather as an indication of some possibilities for understanding implementations of the invention, without excluding interpretations which are not expressly mentioned in the definitions. Accordingly, other implementations fall within the scope of the following paragraphs.

[0021] The term "train" used in the claims relates to any rail vehicle which is designed for travel on rails. This includes, but is not limited to locomotives, passenger cars, freight cars, high-speed trains, subways, trams and light-rail vehicles. Trains can be propelled by various means, including diesel engines, electric engines, or hybrid systems. In the context of this invention, "train" specifically relates to rail vehicles which can be coupled with other rail vehicles to create longer train formations.

[0022] "Coupling" relates to the process of mechanical and / or electrical connection of two or more train units with one another. This typically involves aligning and connecting coupling mechanisms which are located at the ends of railcars and locomotives. Coupling can serve various purposes, including the formation of longer trains, the addition of drive units or the connection of passenger compartments. In the context of this invention, coupling relates specifically to the controlled approach and connection of an active train unit to a passive train unit.

[0023] In the context of this invention, "coupling" can also relate to the process of positioning railcars or units in close proximity to one another, without necessarily establishing a mechanical connection. Close proximity can mean here, for example, less than 1 m. This can include scenarios such as:

[0024] a) Parking trains in a depot or station for efficient use of space.

[0025] b) Positioning a train in the vicinity of a buffer stop at the end of a route.

[0026] c) Alignment of multiple train units for maintenance or inspection purposes.

[0027] d) Arrangement of railcars in a particular configuration for loading or unloading processes.

[0028] e) The virtual coupling of train parts, which then travel behind one another at close intervals.

[0029] In these cases, the term "coupling" or "couple" includes the controlled approach and precise positioning of railcars or trains in relation to one another or to fixed structures. The methods and systems described for obstacle identification during coupling, while coupled, or after coupling may be equally applicable in these situations, where maintaining a safe distance and identifying potential obstacles are important in preventing collisions and ensuring operational efficiency.

[0030] The term "sensor" used in the claims relates to a device which is capable of identifying or measuring physical properties and converting them into signals which can be interpreted by a control system. In the context of this invention, sensors are used for obstacle identification and distance measurement between train units. Sensors can be implemented as hardware devices with associated circuitry and may contain software components for signal processing and data interpretation.

[0031] The term “onboard sensor" relates specifically to sensor devices which are installed directly on a train unit, in contrast to trackside sensors. These can be integrated into the existing systems of the train or added as separate modules. Onboard sensors can be connected to the control systems of the train via various communication protocols such as CAN bus, Ethernet, or wireless networks.

[0032] The "first sensor type" and the "second sensor type" relate to different categories of sensor technology which are used for obstacle identification. These can be implemented as software modules which are installed on a server or cloud infrastructure, or as dedicated hardware components. In a cloud implementation, sensor data processing could be distributed across multiple virtual machines in a scalable architecture. Server implementations could include dedicated rack-mounted hardware in a data center, with redundant power supplies and network connections for reliability.

[0033] Each sensor type, whether implemented in software or hardware, typically includes components for data acquisition, signal processing, and communication. The hardware implementation of such a system would typically include the following:

[0034] a) A processor or microcontroller unit (MCU) for executing sensor algorithms and data processing tasks.

[0035] b) Data storage components such as RAM for temporary data and flash memory or solid-state drives for long-term storage of sensor configurations and historical data.

[0036] c) Input / output interfaces for connection to the actual sensor elements (for example, radar antennae, optical elements) and for communication with other train systems.

[0037] An energy management unit for regulating and distributing energy to the various components.

[0038] In the context of the claimed method, the output of a sensor module serves as input for subsequent processing or decision-making modules. For example, a first module which uses the first sensor type could convert raw data from the sensor into a processed data set representing identified obstacles and distances. This processed data set would then be sent as a digital data telegram to a second module, which could be a decision-making component of the train control system. Data transmission between modules could be facilitated by communication modules which use different data communication technologies.

[0039] Data communication in the context of this invention could make use of various means, including:

[0040] A. Wired technologies:

[0041] i. Ethernet (for example, Gigabit Ethernet for high-speed onboard networks)

[0042] ii. Powerline communication for data transmission via existing power cables

[0043] iii. Serial communication protocols such as RS-485 for robust communication over long distances within the train

[0044] B. Wireless technologies:

[0045] i. 5G or 4G mobile networks for long-range communication with control centers

[0046] ii. WLAN for local data transmission with high bandwidth

[0047] iii. Bluetooth for short-range communication between adjacent components

[0048] iv. Long-range radio systems for communication in areas with limited mobile coverage

[0049] The term "rail vehicle" covers a wide range of vehicles designed for operation on railroad tracks. These include:

[0050] a) Trains: Passenger or freight trains for long distances, consisting of multiple cars and pulled by one or more locomotives

[0051] b) Locomotives: Powered vehicles which are used to pull railcars

[0052] c) Trams: Urban rail vehicles which often share the road space with other road users

[0053] d) Subways: High-capacity urban rail systems which usually run on their own tracks

[0054] e) High-speed trains: Specialized passenger trains which are designed to operate at speeds exceeding 250 km / h

[0055] f) Freight trains: Freight transport trains which may include specialized cars for different types of goods

[0056] g) Light-rail vehicles: Urban or suburban rail transport systems with lower capacity than heavy subways

[0057] In the context of this invention, "rail vehicle" specifically relates to all these types of vehicles which are capable of automated or semi-automated operation and are equipped with the described sensor and control systems for obstacle identification during coupling or operations in close proximity.

[0058] In a preliminary summary, the novel method for the identification of obstacles during train coupling offers several significant advantages over prior solutions:

[0059] Dual sensor approach: The invention uses two different types of onboard sensors and thus offers a more comprehensive and reliable obstacle identification system. This dual sensor approach addresses the limitations of single-sensor systems, which may have difficulty remaining accurate across the entire range of coupling distances.

[0060] Distance-based sensor switching: By using the first sensor type above a predetermined threshold distance and switching to the second sensor type below this threshold value, the method optimizes the identification capabilities for both long and short-range scenarios. This adaptive approach ensures consistent performance throughout the entire coupling process.

[0061] Improved close-range identification: The use of a second sensor type specifically for close-range identification when the distance is below the predetermined threshold value addresses a critical weakness in many existing systems. This function significantly improves safety during the final stages of coupling, where precise obstacle identification is crucial.

[0062] Reduced false positives: By ignoring the first sensor when the distance is below the predetermined threshold value, the method minimizes the risk of false identifications which can occur when long-range sensors have difficulty with accuracy at short distances. This results in smoother, more efficient coupling operations with fewer unnecessary stops or delays.

[0063] Integration of onboard sensors: The use of onboard sensors both for long-range and short-range identification eliminates the need for complex and costly trackside installations. This makes the system more flexible and easier to implement in various railway environments.

[0064] Improved operational flexibility: Without relying on fixed trackside installations, the system enables greater flexibility in the case of coupling locations and processes. Trains can couple safely at any point along the route on which the onboard sensors are able to function effectively.

[0065] Reduced response times: Using only onboard sensors obviates the need for communication between trackside systems and the train. This direct detection approach can lead to faster response times when identifying and reacting to potential obstacles.

[0066] Adaptability to different types of trains: The onboard sensor approach makes the system adaptable to different types and configurations of trains without requiring extensive modifications to the existing infrastructure.

[0067] Improved automation potential: The comprehensive obstacle identification method supports increased automation in train coupling operations, potentially reducing dependence on manual operations and improving the overall efficiency of the system.

[0068] Increased safety: By providing more reliable obstacle identification across the entire range of coupling distances, the method significantly improves safety during one of the traditionally most critical and potentially most dangerous aspects of train operation.

[0069] Together, these advantages represent a significant improvement compared with previous methods of obstacle identification for train coupling, address important limitations of existing systems, and offer a more robust, flexible and efficient solution for modern railway operations.

[0070] In a further preferred embodiment of the method according to the invention, the first sensor is a reflective sensor and the second sensor is a barrier sensor. This combination of types of sensors offers complementary identification capabilities which can improve the overall reliability and effectiveness of the obstacle identification system. The reflective sensor, which is effective at greater distances, enables early identification of potential obstacles when the active train is approaching. The barrier sensor, which could also be referred to as a barrier sensor, on the other hand, is characterized by close-range identification and addresses potential limitations of reflective sensors in the final stages of coupling. This dual sensor approach can ensure continuous and accurate obstacle identification throughout the entire coupling process. The barrier sensor is, for example, a light barrier.

[0071] Alternative implementations of this embodiment could involve the use of different types of reflective sensors, such as a combination of radar and lidar, to provide redundancy and improved performance under various environmental conditions. For the barrier sensor, alternatives could include the use of infrared beams, ultrasound sensors or capacitive proximity sensors, each offering unique advantages with regard to identification range, accuracy and resistance to environmental factors.

[0072] In a further preferred embodiment of the method according to the invention, the reflective sensor includes at least one of the following: a radar sensor, a lidar sensor or a video camera. Each of these types of sensor offers different advantages for obstacle identification. Radar sensors offer performance in various weather conditions and can measure the distance and the speed of objects. Lidar sensors offer high-resolution 3D mapping capabilities which enable obstacle identification and classification. Video cameras can provide visual information and enable image processing techniques for obstacle identification and tracking.

[0073] Alternative implementations could involve the use of multiple types of reflective sensors in combination, such as the merging of data from radar, lidar and video cameras to create a more comprehensive identification system. Another approach could be the use of advanced multimodal sensors which combine multiple sensor technologies in a single unit, potentially reducing complexity and integration challenges.

[0074] In a further preferred embodiment of the method according to the invention, the barrier sensor comprises at least one transmission apparatus for emitting a light beam or high-frequency beam and at least one receiving apparatus for receiving the light beam or high-frequency beam. This configuration enables the identification of obstacles by creating a light barrier between the transmitter and receiver. When an obstacle interrupts the light beam or high-frequency beam, it can be identified, providing a method for close-range identification of obstacles. The use of light beams or high-frequency beams offers advantages such as rapid response times, high sensitivity, and the ability to identify small objects.

[0075] Alternative implementations could explore different types of light sources for the transmission apparatus, such as infrared LEDs, laser diodes, or structured light projectors. The receiving apparatus could be optimized with different types of photodetectors or image sensors to improve sensitivity and reduce false identifications. In addition, the system could be designed with multiple transmitter-receiver pairs in various configurations in order to create a more extensive identification field.

[0076] In a further preferred embodiment of the method according to the invention, both the at least one transmission apparatus and the at least one receiving apparatus are arranged on the active train. This configuration can offer multiple advantages, including simplified installation and maintenance, as all the components are located on a single train unit. It can also enable easier calibration and alignment of the transmitter and receiver, potentially improving identification accuracy. Furthermore, this arrangement enables the active train to have an independent obstacle identification system, reducing dependencies on equipment which is installed on other trains or in the infrastructure. For this embodiment, it may be necessary to have a reflector or a similar apparatus on the passive train to enable the proper functioning of the barrier sensor system.

[0077] Alternative implementations could involve the use of multiple transmitter-receiver pairs, which are distributed across various locations on the active train to create a more extensive identification zone. Another approach could be the use of retroreflective sensors, in which the transmitter and receiver are arranged together and a reflector is installed on the passive train or in the nearby infrastructure.

[0078] A further preferred embodiment of the method according to the invention arranges one of the at least one transmission apparatus and the at least one receiving apparatus on the active train and the other on the passive train. This split configuration enables a larger identification area between the two trains, potentially improving the ability of the system to identify obstacles in the coupling zone. It also enables the creation of a "curtain" of identification between the trains, which may be useful for the identification of obstacles which might enter the space between the trains during the coupling process.

[0079] Furthermore, the barrier sensor can use an individual modulation method when generating the light beam or high-frequency beam. This makes it possible to identify whether the received signal stems from a reflection or from the transmitter of another train. In this way, the safety of the method can be increased.

[0080] Alternative implementations could explore various arrangements of multiple transmitter-receiver pairs between the active and passive trains to create overlapping identification fields. Another approach could be a hybrid system in which some transmitter-receiver pairs are divided between the trains, while others are self-contained on the active train, providing redundancy and extended coverage.

[0081] In a further preferred embodiment of the method according to the invention, the method also comprises the use of the first sensor to determine the distance between the active train and the passive train while the active train is approaching the passive train. This function enables the system to monitor the distance between the trains, enabling control of the approach speed and the timing of the sensor crossover. By using the first sensor (typically a reflective sensor) for distance measurement, the system can use its capabilities for longer ranges in order to control the approach from an early stage.

[0082] Alternative implementations could involve the merging of distance data from multiple sensors to improve accuracy and reliability. Another approach could be the use of specialized distance measurement sensors, such as time-of-flight cameras or structured light sensors, in addition to obstacle identification sensors.

[0083] In a further preferred embodiment of the method according to the invention, the method further comprises temporary halting of movement of the active train when an obstacle is identified by the second sensor if the distance is below the predetermined threshold value; and resuming movement of the active train when the obstacle is no longer identified. This safety function ensures that the coupling process is halted when an obstacle is identified in close proximity in order to prevent potential collisions or damage. The ability to automatically resume movement when the obstacle has been removed enables efficient operation while at the same time maintaining safety.

[0084] Alternative implementations could include more differentiated responses to obstacle identification, such as gradual deceleration instead of an immediate stop, depending on the type and position of the identified obstacle. Another approach could be the implementation of a graded response system in which various types or sizes of obstacles trigger different levels of braking action or evasive maneuvers.

[0085] In a further preferred embodiment of the method according to the invention, the method further comprises adjustment of the approach speed of the active train based on a combination of data from the first sensor when the distance exceeds the predetermined threshold value, and data from the second sensor when the distance is below the predetermined threshold value. This adaptive speed control enables smooth and efficient coupling operations while at the same time maintaining safety. By using data from both types of sensors, the system can optimize the approach speed based on long-range information and refine it with short-range data when the trains are approaching one another.

[0086] In some implementations, the predetermined threshold value can be set to a distance of 3 meters. For many train configurations, this distance can provide a suitable transition point between long-range and short-range identification. At distances of more than 3 meters, the first sensor (such as a radar or lidar system) can effectively identify larger obstacles and provide accurate distance measurements. When the active train approaches within 3 meters of the passive train, the second sensor (such as a light barrier system) can take over for more precise close-range identification. The exact threshold distance can be adjusted on the basis of factors such as train size, coupling mechanism design, sensor capabilities and operational requirements. In some cases, the threshold value can be adjusted dynamically on the basis of environmental conditions or specific train properties.

[0087] Alternative implementations could include more complex speed control algorithms which take into account additional factors such as train weight, track condition, or the weather. Another approach could be the implementation of machine learning techniques to continuously improve speed adjustment based on historical coupling data and results.

[0088] Based on known train control apparatuses, the invention further addresses the challenge of providing an apparatus which enables efficient and accurate obstacle identification during train coupling and at the same time improves safety and operational flexibility.

[0089] With the above and other objects in view there is also provided, in accordance with the invention, a train control apparatus. The same advantages apply analogously, as explained above with reference to the method according to the invention.

[0090] Based on the prior art systems for the identification of obstacles during train coupling, the invention further addresses the challenge of providing a system which enables efficient and accurate obstacle identification during train coupling and at the same time improves safety and operational flexibility.

[0091] Based on the prior art computer program products for train control, the invention also addresses the challenge of providing a computer program product which enables efficient and accurate obstacle identification during train coupling and at the same time improves safety and operational flexibility.

[0092] With the above and other objects in view there is also provided, in accordance with the invention, a computer program product, which provides for the same advantages as described above with reference to the novel method.

[0093] Other features which are considered as characteristic for the invention are set forth in the appended claims.

[0094] Although the invention is illustrated and described herein as embodied in a method and system for obstacle identification during and after train coupling, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.

[0095] The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. BRIEF DESCRIPTION OF THE FIGURES

[0096] FIG. 1 is a side view of a train coupling system according to an embodiment of the invention, showing an active train which is approaching a passive train;

[0097] FIG. 2 shows the train coupling system from FIG. 1 with the active train closer to the passive train;

[0098] FIG. 3 shows the train coupling system from FIG. 1 with the barrier sensor beams connected between the trains;

[0099] FIG. 4 shows the train coupling system from FIG. 1 with the active train coupled to the passive train; and

[0100] FIG. 5 is a flow chart which illustrates a method for obstacle identification for train operations according to an embodiment of the invention.DETAILED DESCRIPTION OF THE INVENTION

[0101] Referring now to the figures of the drawing in detail and first, in particular, to FIGS. 1-4, which show a preferred embodiment of the system according to the invention, there is illustrated an overall structure of a train coupling obstacle identification system. FIG. 1 shows an active train 1 which is approaching a passive train 2 on a track 3. The active train 1 includes a coupling mechanism 5 at its front end for connection to a corresponding coupling mechanism 5 on the passive train 2.

[0102] The active train 1 is equipped with at least one first onboard sensor of a first sensor type, which in this embodiment is a reflective sensor 6. The reflective sensor 6 is used for the identification of obstacles when a distance 12 between the active train 1 and the passive train 2 exceeds a predetermined threshold value. The active train 1 also comprises at least one second onboard sensor of a second sensor type, which in this embodiment is a barrier sensor 7. The barrier sensor 7 is used for the identification of obstacles when the distance 12 between the active train 1 and the passive train 2 is below the predetermined threshold value.

[0103] FIG. 2 shows the active train 1 and the passive train 2 at a shorter distance 12 compared to FIG. 1. In this figure, the reflective sensor 6 is still active for obstacle identification. FIG. 3 shows the trains at an even shorter distance 12, where the barrier sensors 7 on both trains have made contact. At this point, the system ignores the reflective sensor 6 for the identification of obstacles, as shown in FIGS. 3 and 4.

[0104] The system comprises a train control apparatus 13 which is configured to perform the method for the identification of obstacles. The train control apparatus 13 manages the transition between the use of the reflective sensor 6 and the barrier sensor 7 based on the distance 12 between the trains.

[0105] A computer program product which comprises instructions for the identification of obstacles during the approach of an automatically controlled active train 1 to a passive train 2 for coupling can be used to control the overall operation of the obstacle identification system. This computer program product can be executed by the train control apparatus 13 to implement the described obstacle identification method.

[0106] As noted above, FIG. 1 shows a side view of a train coupling system. The system comprises an active train 1 which is approaching a passive train 2 on a track 3. The direction of travel 4 of the active train 1 is indicated by an arrow pointing to the passive train 2. In the illustration of FIG. 1, the active and passive trains are separated by a spacing distance 12.

[0107] The system comprises multiple components for facilitating a safe coupling process. Both the active train 1 and the passive train 2 are equipped with coupling mechanisms 5 at their facing ends. The active train 1 has a reflective sensor 6 and a barrier sensor 7 for the identification of obstacles and to ensure safe coupling. The passive train 2 likewise includes a barrier sensor 8 which works together with the barrier sensor 7 of the active train 1.

[0108] A braking curve 9 (i.e., an acceleration slope) is shown above the active train 1 and represents the deceleration profile when the active train 1 is approaching the passive train 2. The barrier sensors 7 and 8 each generate a beam 10 between the two trains. The beam 10 can be a light beam which enables the barrier sensors 7 and 8 to establish contact between the trains.

[0109] An identification zone 11 of the reflective sensor 6 is highlighted between the two trains and indicates the area monitored for obstacles. The reflective sensor 6 may comprise at least one of the following: a radar sensor, a lidar sensor or a video camera. These types of sensors enable effective obstacle identification at long distances when the active train 1 is approaching the passive train 2.

[0110] The barrier sensor 7 comprises at least one transmission apparatus for emitting a light beam and at least one receiving apparatus for receiving the light beam. In the embodiment shown in FIG. 1, one of the transmission apparatus and the receiving apparatus is arranged on the active train 1 and the other on the passive train 2. This configuration enables the creation of an identification "curtain" between the trains.

[0111] An alternative implementation could involve both the transmission apparatus and the receiving apparatus being arranged on the active train 1. This configuration could simplify installation and maintenance as all the components would be located on a single train unit.

[0112] FIG. 1 effectively illustrates the spatial relationship between the trains and the various sensors and mechanisms which are involved in the coupling process. The active train 1 uses the onboard sensors to safely approach the passive train 2 while continuously monitoring the distance 12 to the passive train 2 and the area between them for possible obstacles.

[0113] The progress of the obstacle identification and train coupling process is illustrated hereinafter in the sequential illustrations of FIGS. 1-4.

[0114] FIG. 1 shows an initial approach phase in which an active train 1 approaches a passive train 2 on a track 3. The active train 1 is equipped with a reflective sensor 6 and a barrier sensor 7. The passive train 2 is equipped with a barrier sensor 8. An identification zone 11 is established between the active train 1 and the passive train 2 by means of the reflective sensor 6.

[0115] During this initial approach, the reflective sensor 6 is used to determine the distance 12 between the active train 1 and the passive train 2. The reflective sensor 6 can be a radar sensor, a lidar sensor or a video camera, which are capable of monitoring a long distance. Based on the data from the reflective sensor 6, the approach speed of the active train 1 can be adjusted to ensure a safe and controlled approach.

[0116] FIG. 2 shows a phase in which the active train 1 has drawn closer to the passive train 2. The reflective sensor 6 on the active train 1 continues to be used for obstacle identification in this phase. The barrier sensors 7 and 8 on the active train 1 and passive train 2, respectively, are approaching the point at which they will establish a connected beam 10. In this phase, the system may potentially be preparing to transition from primarily using the reflective sensor 6 to using the barrier sensors 7 and 8 for obstacle identification as the trains continue to approach one another. The predetermined threshold value has not yet been reached in this figure, so the reflective sensor 6 remains active for the identification of obstacles.

[0117] FIG. 3 shows a further approach phase in which the beam 10 between the barrier sensors 7 and 8 is established in full. At this point, the system already relies on the barrier sensors 7 and 8 for obstacle identification, while the reflective sensor 6 is ignored, or is disregarded during the obstacle identification process.

[0118] The changeover from the use of the reflective sensor 6 to the barrier sensors 7 and 8 takes place when the distance 12 between the active train 1 and the passive train 2 falls below the predetermined threshold value. This threshold value can be determined on the basis of the distance measurement provided by the reflective sensor 6.

[0119] During the approach, the system continuously adjusts the speed of the active train 1 based on the braking curve 9.

[0120] If an obstacle is identified by the barrier sensors 7 and 8 and if the distance 12 is below the predetermined threshold value, movement of the active train 1 can be temporarily halted. The system continuously monitors the area between the active train 1 and the passive train 2 using the barrier sensors 7 and 8. When the obstacle is no longer identified, movement of the active train 1 can be resumed so that the coupling process can be continued.

[0121] If the distance between the active train 1 and the passive train 2 falls below the predetermined threshold value, the system will ignore or deactivate the first sensor (in this case, the reflective sensor 6) for obstacle identification purposes. This transition can take place because the second sensor (for example, the barrier sensor 7) becomes more reliable at close range. By ignoring the first sensor below the threshold distance, the system can reduce the risk of false positives or inaccurate measurements which may occur when long-range sensors are used in close-range situations. This approach can help to ensure that the most suitable and most reliable sensor is used for obstacle identification during each phase of the coupling or close positioning process, potentially improving overall safety and efficiency. However, it is important to note that even though the first sensor is ignored for obstacle identification, it can still be used for distance measurement between the active train 1 and the passive train 2. This can enable the system to retain accurate distance information throughout the coupling or positioning process, even when it switches to the second sensor for obstacle identification in the final approach phase.

[0122] FIG. 4 shows the final phase of the coupling process, in which the active train 1 was successfully coupled with the passive train 2. The barrier sensors 7 and 8 continue to monitor the area between the coupled trains for possible obstacles.

[0123] Throughout the process, the obstacle identification system is integrated into the train control apparatus 13 to automatically adjust the approach speed based on sensor data and the current phase of the coupling process. This integration ensures a safe and efficient coupling operation while at the same time maintaining the ability to respond rapidly to identified obstacles.

[0124] In a further preferred embodiment of the method according to the invention, FIG. 5 shows a flow chart of a method 100 for obstacle identification during train coupling. The method 100 begins with step 102, in which a first onboard sensor is used for obstacle identification when an active train 1 is approaching a passive train 2. This step corresponds to the situation shown in FIG. 1, in which the active train 1 is located at a distance from the passive train 2 and uses a reflective sensor 6 to identify obstacles in an identification zone 11 between the trains.

[0125] The process then proceeds to step 104, which involves determining whether the distance between the trains is above a predetermined threshold value. This step is shown in FIG. 2, where the active train 1 has drawn closer to the passive train 2, but the distance 12 is still above the predetermined threshold value.

[0126] If the distance 12 is above the predetermined threshold value (“yes” path), the method 100 continues to use the first sensor, as shown in step 106. This corresponds to the continued use of the reflective sensor 6 for obstacle identification, as shown in FIG. 2.

[0127] If the distance 12 is not above the predetermined threshold value (“no” path), the method 100 proceeds to step 108, in which a second onboard sensor is used for obstacle identification. This transition is shown in FIG. 3, where the active train 1 has approached sufficiently close to the passive train 2 for a barrier sensor 7 to become effective.

[0128] Subsequently, in step 110, the first sensor for obstacle identification is ignored. This step is also shown in FIG. 3, where the reflective sensor 6 is no longer used for obstacle identification.

[0129] The method 100 concludes with step 112, in which the approach is continued using data from the second sensor. This final phase is shown in FIG. 4, where the active train 1 completes its approach to the passive train 2 using only the barrier sensor 7 for obstacle identification.

[0130] To ensure fail-safe operation, the system includes redundant sensors and processing units. For example, multiple reflective sensors 6 and barrier sensors 7 may be installed on the active train 1, with a determination system to determine the final obstacle identification status.

[0131] The obstacle identification system is integrated into the overall control and braking system of the train. This integration enables automatic speed adjustments and emergency braking based on the obstacle identification data from both the reflective sensor 6 and the barrier sensor 7.

[0132] A separate, simplified backup identification system is implemented for basic safety functions. This backup system may use different sensor technologies or simplified versions of the primary sensors to provide a last line of defense against obstacles during the coupling process.

Claims

1. A method for identifying obstacles while an automatically controlled active train (1) is approaching a passive train for coupling, the method comprising:providing at least one first onboard sensor of a first sensor type configured for identifying obstacles between the active train and the passive train when a distance between the active train and the passive train exceeds a predetermined threshold value;providing at least one second onboard sensor of a second sensor type which differs from the first sensor type, and using the at least one second sensor for identifying obstacles between the active train and the passive train when the distance between the active train and the passive train lies below the predetermined threshold value; andignoring the first sensor for identifying obstacles when the distance between the active train and the passive train lies below the predetermined threshold value.

2. The method according to claim 1, wherein the first sensor is a reflective sensor and the second sensor is a barrier sensor.

3. The method according to claim 2, wherein the reflective sensor comprises at least one sensor selected from the group consisting of a radar sensor, a lidar sensor, and a video camera.

4. The method according to claim 2, wherein the barrier sensor comprises at least one transmission apparatus for emitting a light beam or high-frequency beam and at least one receiving apparatus for receiving the light beam or the high-frequency beam.

5. The method according to claim 4, wherein both the at least one transmission apparatus and the at least one receiving apparatus are mounted on the active train.

6. The method according to claim 4, wherein one of the at least one transmission apparatus and the at least one receiving apparatus is arranged on the active train and another of the at least one transmission apparatus and the at least one receiving apparatus is arranged on the passive train.

7. The method according to claim 1, which comprises using the first sensor to determine the distance between the active train and the passive train while the active train is approaching the passive train.

8. The method according to claim 1, which comprises:temporarily halting of movement of the active train when an obstacle is identified by the second sensor and the distance between the active train and the passive train is below the predetermined threshold value; andresuming the movement of the active train when the obstacle is no longer identified between the active train and the passive train.

9. The method according to claim 1, which comprises adjusting an approach speed of the active train based on a combination of data from the first sensor when the distance exceeds the predetermined threshold value and data from the second sensor when the distance lies below the predetermined threshold value.

10. A train control apparatus for controlling an automatically controlled active train, comprising a controller configured to perform the method according to claim 1.

11. A system for identifying obstacles while an automatically controlled active train is approaching a passive train for coupling, comprising:at least one first onboard sensor of a first sensor type configured for an identification of obstacles between the active train and a passive train when a distance between the active train and the passive train exceeds a predetermined threshold value;at least one second onboard sensor of a second sensor type which differs from the first sensor type, said at least one second onboard sensor being configured for an identification of obstacles between the active train and the passive train when the distance between the active train and the passive train is below the predetermined threshold value; andat least one train control apparatus having a controller configured to perform the method according to claim 1.

12. The system according to claim 11, wherein said first sensor is a reflective sensor and said second sensor is a barrier sensor.

13. The system according to claim 12, wherein said reflective sensor is at least one sensor selected from the group consisting of a radar sensor, a lidar sensor, and a video camera.

14. The system according to claim 11, wherein said first sensor, said second sensor, and said train control apparatus are arranged on the active train.

15. A non-transitory computer program product, comprising instructions which, when the instructions are executed by a computer, cause the computer to perform a method according to claim 1.

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