Architecture for data transmission between multiple electric traction vehicles and corresponding remote control centers

Abstract

An architecture (10) for data transmission between a plurality of electric traction vehicles (12) moving in a transport network (11) and a backbone Ethernet network (14) is described, the transport network (11) comprising a plurality of substations (15) connected to a low / medium voltage supply network (16) of the vehicles (12), the invention relates to a power supply network (16) for continuous data transmission over a vehicle (12) and over a backbone Ethernet (14) according to a BPLC communication mode by means of a transmission and decoupling system (20) interposed between the vehicle (12) and a substation (15) connected to the power supply network (16), said transmission and decoupling system (20) comprising:-on-board equipment (20A) adapted to be placed on each vehicle (12); and-a plurality of grounding devices (20B), each grounding device being adapted to be coupled to at least one of the substations (15), the in-vehicle device (20A) being connectable to a corresponding grounding device (20B) when the vehicle (12) passes through one of the grounding devices (20B), where each of the grounding devices (20B) comprises at least an adapter (23B), the adapter (23B) being adapted to be coupled to at least one of the substations (15). The adapter (23B) is directly connected to the backbone Ethernet (14) and is a PLC main device; and the on-board device (20A) of each vehicle (12) comprises an adapter (23A) as a PLC slave device.

Description

Technical Field

[0001] The present invention relates to an architecture for data transmission between a plurality of vehicles and a remote control center of a transportation network.

[0002] The present invention relates particularly but not exclusively to an architecture for data transmission for communication in a mass transport network such as a railway or underground network, and the following description is made with reference to this field of application, the sole purpose of which is to simplify the exposition of the present invention. Background Art

[0003] It is well known that in the so-called mass transport field, systems based on the use of electric motors are widely used. The systems defined as electric traction are the most technologically advanced systems today.

[0004] In particular, all recently built high-speed railways and most underground lines are made of electric traction systems.

[0005] The main reasons for the success of electric traction systems, especially in the mass transport field, in addition to the lower environmental pollution generated, are their electromechanical reliability and higher operating affordability, especially in the case of heavy traffic. There is also suitable equipment that can recover energy during downhill or deceleration or braking steps, thus further improving the performance of these systems.

[0006] In its most general form, an electric traction mass transport system includes a plurality of vehicles adapted to accommodate a plurality of passengers or a plurality of vehicles moving on a suitable track and a power supply line capable of powering the vehicles; the system is also referred to as a transport network.

[0007] Most transport networks use so-called overhead power supply lines, where the vehicles are equipped with pantograph structures for connecting to the power supply line above the track. In particular, the term pantograph defines a device for obtaining current from an overhead contact line, which is usually placed on the roof of a railway vehicle or a tram vehicle, etc.

[0008] Alternatively, it is known to use so-called third-rail power supply, where an additional rail is placed between or beside two rails or tracks (such as those on which vehicles such as trains or subways pass), and electrical contact is ensured by a sliding conductive shoe or a lateral wheel rotating thereon, providing a suitable insulating cover to protect possible workers on the track.

[0009] One of the problems that should be addressed in managing the above types of transport networks is data transmission, especially the data transmission between individual means of transport circulating in the network and their control center.

[0010] The said data transmission is usually assigned to a dedicated data network, which includes optical and copper cable transmission supports inserted into the system infrastructure along the transport network, especially for transmitting data related to circulating vehicles, as well as corporate communications of an administrative and management type. Currently in Italy, the railway data network covers more than 12,000 km of railway lines and constitutes the basic support for all railway transmission systems.

[0011] As is well known, the Global System for Mobile Communications – Railway (GSM-R) is a radio communication system for transport networks, which is standardized in Europe and provides a wide range of voice, SMS, and data services necessary to ensure the interoperability and proper operation of the entire transport network. At the end of 2021, the GSM-R signal in Italy covered 11,633 km of national railway lines (conventional and HS / HC railway lines, i.e., high-speed / high-capacity railway lines), and the coverage of the remaining part of the railway lines is guaranteed by the roaming of mobile phone operators.

[0012] Obviously, fixed telephone lines are also used to manage transport lines. In particular, circulation and maintenance operators use the fixed telephone system for communications related to railway operations. In addition, dedicated telephone stations are installed on the consoles of circulation operators (such as station masters (Italian: DM: “dirigenti movimento”), train dispatchers (Italian: DC: “diriginti central”), and operating train dispatchers (Italian: DCO: “diriganti central operative”), etc.), in the electric traction (ET) consoles (such as driver's cabs, electric substations (ESS), central consoles of the Divisione Operativa Trasporti Elettrici (DOTE)), in yards and along the line, outdoors or in corridors.

[0013] In the past few years, the above-mentioned communication systems are shifting from traditional telephone systems to Internet Protocol (IP) networks and Voice over Internet Protocol (VoIP) systems.

[0014] A communication system for a formation (such as a train, etc.) is described in the patent serial number US 8,825,239 B2 issued in the name of General Electric Company on September 2, 2014, and the said system does not allow continuous data transmission in any case when the formation is moving.

[0015] The programmable logic controller (PLC) communication in vehicles was also mentioned in the article titled "Proof of Concept of Vehicle to Infrastructure Power Line Communication Link for Tramway CCTV" published by Belhassen Hatem et al. in the 13th volume, issue 3 of the IEEE INTELLIGENT TRANSPORTATION SYSTEMS MAGAZINE on March 3, 2020.

[0016] In the most modern transportation networks, wired data transmission modes are typically used specifically for stations, and wireless data transmission modes are used specifically for communication between moving vehicles and the corresponding remote control centers.

[0017] However, the presence of moving vehicles makes the performance of wireless communication not fully determined, and dedicated equipment needs to be installed along the routes where the vehicles travel. The additional equipment can cause significant economic and environmental impacts, especially due to the presence of transmission antennas.

[0018] The technical problem of the present invention is to provide an architecture for continuous data transmission in a transportation network that includes multiple vehicles moving on tracks, which are powered by low / medium voltage power supply lines and communicate with a remote control center, having structural and functional characteristics that ensure reliable, uninterrupted transmission with low additional costs, overcoming the limitations and drawbacks that still affect the solutions proposed according to the prior art. Summary of the Invention

[0019] The solution idea under the present invention is to modify the BPLC communication mode (Broadband over Power Lines Communication) to allow continuous data transmission between vehicles moving in a transportation network and a remote control center using the low / medium voltage power supply lines of the same vehicle. The term low / medium voltage refers to voltage values below 30 kV.

[0020] Based on the above solution idea, this technical problem is solved by an architecture for data transmission between multiple electric traction vehicles moving in a transportation network and a backbone Ethernet. The transportation network includes multiple substations connected to the low / medium voltage power supply network of the vehicles. It is characterized in that the power supply network is used for continuous data transmission between the vehicles and the backbone Ethernet according to the BPLC communication mode through a transmission and decoupling system. The transmission and decoupling system is inserted between the vehicles and the substations connected to the power supply network. The transmission and decoupling system includes:

[0021] - On-vehicle equipment, which is adapted to be placed on each vehicle; and

[0022] - Multiple grounding devices, each grounding device being adapted to be coupled to at least one of the substations.

[0023] When a vehicle transits a grounding device among the grounding devices, the on-vehicle equipment can connect to the corresponding grounding device.

[0024] Among them, each of the grounding devices includes at least an adapter, the adapter is directly connected to the backbone Ethernet and is a PLC master device; and the on-vehicle equipment of each vehicle includes an adapter as a PLC slave device.

[0025] More specifically, the present invention includes the following additional and optional features, either alone or in combination when necessary.

[0026] According to one aspect of the present invention, the on-vehicle equipment can connect to the grounding device based on a signal-to-noise ratio suitable for ensuring two-way communication with the backbone Ethernet.

[0027] In addition, the on-vehicle equipment can connect to the grounding device according to additional link quality parameters, which are selected from the following: the authentication status of the master PLC module and / or the slave PLC module, the received signal strength indication (RSSI) of the beacon frame between the master PLC module and the slave PLC module, the automatic gain control (AGC) on the receiver's programmable gain amplifier (RxPGA), and the physical data rate based on dynamically exchanging data on the estimated channel between the master PLC module and the slave PLC module. The AGC is used to compensate for the amplitude of the signal received by the receiver.

[0028] According to another aspect of the present invention, the adapter includes at least a first PLC module of a first type and a second PLC module of a second type. The first PLC module of the first type and the second PLC module of the second type are connected to a management module serving as a gateway. The adapter is adapted to convert digital data into an analog radio frequency signal, connect to the low / medium voltage local power supply line of the vehicle, and connect to a grounding device when connected to the in-vehicle device.

[0029] According to the said aspect of the present invention, the in-vehicle device of each vehicle may further include a decoupler, which is adapted to eliminate the continuous component of the supply voltage on the local power supply line, implement a high-pass filter to eliminate the low-frequency noise in the input signal, and obtain the information signal to be transmitted to the grounding device when connected to the in-vehicle device, so as to achieve connection to the power supply network and data transmission to the backbone Ethernet according to the BPLC communication mode.

[0030] According to another aspect of the present invention, the decoupler may be a passive component and the adapter may be an active component.

[0031] According to yet another aspect of the present invention, the in-vehicle device may be connected to the local network of the vehicle.

[0032] According to another aspect of the present invention, the architecture for data transmission may include a plurality of grounding devices of a first type and a plurality of grounding devices of a second type that are alternating and spaced apart from each other according to distance.

[0033] More specifically, each of the grounding devices of the first type may include at least one adapter, which in turn includes a PLC module of the first type and a corresponding management module. The corresponding management module is capable of connecting to the first PLC module of the adapter of the first type of the in-vehicle device. Each of the grounding devices of the second type may include at least one adapter, which in turn includes a PLC module of the second type and a corresponding management module. The corresponding management module is capable of connecting to the second PLC module of the adapter of the second type of the in-vehicle device.

[0034] According to another aspect of the present invention, the grounding devices of the first type and the grounding devices of the second type may respectively include management modules connected to the PLC modules of the first type and the PLC modules of the second type.

[0035] According to another aspect of the present invention, each of the grounding devices may include a decoupler, which is adapted to eliminate the continuous component from the supply voltage, implement a high-pass filter to eliminate the low-frequency noise in the input signal, and obtain the information signal to be transmitted to the in-vehicle device.

[0036] According to another aspect of the present invention, each of the grounding devices may further include a connector block and a basic device.

[0037] According to another aspect of the present invention, the decoupler may be a passive component and the adapter may be an active component.

[0038] In addition, according to another aspect of the present invention, the substation may be selected from: a railway or tramway track station, a railway or tramway track stop, a substation of a railway or tramway track network, and other structures located along a railway or tramway track line.

[0039] In addition, the vehicle may be selected from: a train, a trolleybus, a tram, and other electric traction transportation means.

[0040] According to another aspect of the present invention, the grounding device may be placed at a distance of 1 m to 1500 m from the vehicle on-board device.

[0041] In addition, according to another aspect of the present invention, the architecture for data transmission may perform a handover of data from the grounding device to the next device by verifying a minimum value of the signal-to-noise ratio transmitted between the grounding device and the on-board device.

[0042] According to another aspect of the present invention, the architecture for data transmission may transmit:

[0043] - Critical data, i.e., data necessary for the vehicle and the transportation network to function properly as a whole; and

[0044] - Non-critical data, i.e., data related to improving the comfort of passengers on the vehicle.

[0045] This technical problem is also solved by a method for continuous data transmission in the architecture as described above, wherein the grounding devices are divided into a first type and a second type and alternate with each other between the first type and the second type, and each device type is adapted to be connected to a different module of the on-board device. The method includes the following steps:

[0046] Transmitting a signal from each module of the on-board device to the grounding devices of the same type;

[0047] Verifying the signal-to-noise ratio value of the transmitted signal as a link quality parameter;

[0048] Selecting the signal with the maximum signal-to-noise ratio value from the transmitted signals; and

[0049] Connecting one of the modules of the on-board device to one of the grounding devices corresponding to the signal having the maximum signal-to-noise ratio value,

[0050] Repeating the above steps during the following times when the vehicle is moving to ensure continuous data transmission.

[0051] According to one aspect of the present invention, additional link quality parameters can be used to evaluate a grounding device of one of the modules to be connected to a vehicle-mounted device.

[0052] In particular, the additional link quality parameters can be selected from: the authentication status of the master PLC module and / or the slave PLC module, the RSSI (Received Signal Strength Indication) of the beacon frame between the master PLC module and the slave PLC module, the AGC (Automatic Gain Control) on the RxPGA (programmable gain amplifier of the receiver) for compensating the signal amplitude received from the receiver, and the physical data rate based on the data dynamically exchanged on the estimated channel between the master PLC module and the slave PLC module.

[0053] According to another aspect of the present invention, handover rules can be used to drive a handover mechanism selected from: the evaluation time of the link quality parameter; the time between two scans, which is the frequency of retrieving information and roaming estimation from the slave module of the grounding device; the no-return delay, which is the minimum delay before returning to the used master module; and the smoothing factor, which is the weighted importance of the latest signal and the old signal.

[0054] According to another aspect of the present invention, different combinations of handover rules and additional link quality parameters can be used according to the application scenario.

[0055] The features and advantages of the architecture for data transmission according to the present invention will be apparent from the description of the embodiments given by way of indicative and non-limiting examples in the following with reference to the accompanying drawings. Description of the Drawings

[0056] In the said drawings:

[0057] - Figure 1 Schematically shows an architecture for data transmission of a transportation network including a plurality of mobile vehicles manufactured according to the present invention;

[0058] - Figure 2 Shows in more detail the Figure 1 architecture;

[0059] - Figure 3 Shows the Figure 1 system used by the architecture, which has a grounding part and a vehicle-mounted part of a vehicle moving in the transportation network; and

[0060] - Figure 4 and Figure 5 Shows in more detail the Figure 3 system. Detailed Description

[0061] Referring to the said drawings, in particular Figure 1, the architecture for data transmission according to the present invention is generally schematically indicated by 10.

[0062] It should be noted that the accompanying drawings represent schematic diagrams of the architecture according to the present invention and are not drawn to scale, but are drawn to emphasize the important features of the present invention. In addition, the different aspects of the present invention represented by examples in the accompanying drawings can be clearly combined with each other and interchanged from one embodiment to another.

[0063] The architecture 10 for data transmission is particularly suitable for connecting a plurality of vehicles 12 moving in a transportation network 11 (e.g., along a track 13) to a so-called backbone network or a network of the grounded type 14, which is a network interconnected with other local area network (LAN) sub-networks for exchanging information between the LAN sub-networks (especially Ethernet networks). The transportation network 11 includes a plurality of substations 15, which are connected to a low / medium voltage power supply network 16 for supplying electric traction energy (EET) to the vehicles 12 and local power supply lines 17 connected to the vehicles 12 in the form of, for example, overhead power supply lines. Each vehicle 12 is equipped with a pantograph 18 for connecting to the local power supply line 17. It is also obvious that vehicles 12 with third-rail power supply can be used, and the low / medium voltage power supply network 16 is adapted to supply electric traction energy to the vehicles 12 through the third rail (as a supplement to the track 13), so the third rail is basically a local power supply line. It should be noted that the term low / medium voltage refers to a voltage value below 30 kV.

[0064] According to the present invention, the power supply network 16 is also used for continuous data transmission between the vehicles 12 and the backbone Ethernet 14, especially using the BPLC communication mode (Power Line Broadband Communication).

[0065] The present invention actually starts from the following considerations: The power line broadband BPLC communication mode allows the use of a common wired network for power distribution and digital data transmission at a relatively high speed. In order to apply the BPLC communication mode to the transportation network, the following key aspects are advantageously faced and overcome:

[0066] - Making data communication compatible with low / medium voltage power supply networks such as the power supply network 16 of the transportation network 11, etc.; and

[0067] - Ensuring connection under highly time-varying and dynamic conditions due to the movement of the vehicles 12 on the track 13 of the transportation network 11 and the exchanged information, which can change within a specified time interval.

[0068] To overcome these difficulties, the architecture 10 for data transmission is advantageously equipped with a transmission and decoupling system 20, which is inserted between a vehicle 12 moving in a transportation network 11 and a substation 15 connected to a power supply network 16. The transmission and decoupling system particularly includes:

[0069] - On-vehicle equipment 20A, which is adapted to be placed on each vehicle 12 of the transportation network 11; and

[0070] - A plurality of grounding devices 20B, each grounding device 20A being adapted to be coupled to at least one substation 15 connected to the power supply network 16.

[0071] The architecture 10 for data transmission includes a backbone Ethernet 14, which communicates bidirectionally with the transmission and decoupling system 20 of the vehicle 12 and allows continuous bidirectional data transmission between the vehicle 12 and the backbone Ethernet 4.

[0072] Suitably, as Figure 2 schematically shown, the on-vehicle equipment 20A of each vehicle 12 includes a decoupler 22A, which is a passive component and is connected to a local network 21 and the grounding device 20B of the substation 15 through a local power supply line 17. The local power supply line provides electric traction energy EET for the same vehicle and is connected to the power supply network 16. Similarly, the decoupler 22A of a vehicle with third-rail power supply can be connected to the grounding device 20B through a connection via the third rail used as the local power supply line.

[0073] Suitably, the substation 15 where the grounding device 20B is to be installed can be selected, for example, from railway or tramway stations, railway or tramway stops, railway or tramway substations, or other structures located along railway or tramway lines.

[0074] Similarly, the on-vehicle equipment 20A can be installed on, for example, trains, trolleybuses, trams, and other similar transportation means.

[0075] More specifically, as Figure 3 shown, the on-vehicle equipment 20A includes a decoupler 22A to achieve connection with a low / medium voltage power supply line (such as the local power supply line 17 of the vehicle 12) and perform data transmission according to the BPLC communication mode through the power supply network 16.

[0076] The on-vehicle equipment 20A further includes an adapter 23A, which is an active component for converting digital data into an analog radio frequency signal. The analog radio frequency signal will be sent to the decoupler 22A and then sent to the backbone Ethernet 14 through the grounding device 20B.

[0077] In particular, decoupler 22A eliminates the continuous component of the supply voltage on the local supply line 17 and allows it to be connected to adapter 23A.

[0078] If powered by a pantograph, the passive component, i.e., decoupler 22A, can be installed outside vehicle 12, for example, on the roof of the vehicle, or under its fairing in the case of third-rail power supply, while the active component, i.e., adapter 23A, is usually installed inside the same vehicle, for example, inside the carriage.

[0079] Similarly, grounding device 20B includes decoupler 22B (passive component) and adapter 23B (active element). Decoupler 22B is also used to eliminate the continuous component in the supply voltage, and adapter 23B is used to convert digital data into an analog radio frequency signal for transmission to backbone Ethernet 14. Thus, advantageously, no antenna along track 13 of transportation network 11 is required, and communication is carried out by power supply network 16 and backbone Ethernet 14.

[0080] In other words, on-vehicle device 20A includes decoupler 22A (passive component) and adapter 23A (active component). Similarly, grounding device 20B includes decoupler 22B (passive component) and adapter 23B (active component).

[0081] Grounding device 20B may also include a power supply junction box 24 along track 13 and possibly other basic equipment (not shown).

[0082] Suitably, decoupler 22A of on-vehicle device 20A and decoupler 22B of grounding device 20B may be equivalent to each other respectively.

[0083] As Figure 4 shown in more detail, adapter 23B of grounding device 20B is connected to backbone Ethernet 14 and decoupler 22B in a bidirectional manner, including at least one PLC module 25B and a management module 26B of the PLC module 25B. The management module 26B basically acts as a gateway. Adapter 23B is a PLC master device directly connected to backbone Ethernet 14 and thus connected to one or more remote control centers connected thereto.

[0084] In addition, decoupler 22B includes an input terminal pair P1, which receives an input signal or a local signal affected by noise, especially low-frequency interference, and is configured to decouple the continuous traction voltage and provide a high-pass filter, which can also eliminate low-frequency noise and obtain a correct information signal available for transmission to on-vehicle device 20A at output terminal pair P2.

[0085] Suitably, the architecture 10 for data transmission according to the present invention includes a plurality of grounding devices 20B, and the grounding device 20B includes an adapter 23B, its PLC module 25B, a management module 26B, and a decoupler 22B.

[0086] The decoupler 22A of the on-vehicle device 20A has a structure corresponding to one of the decouplers 22B of the grounding device 20B and performs a similar high-pass filtering operation on the received signal.

[0087] In fact, it should be noted that when an electric traction vehicle is running, due to the presence of vehicle traction motors, on-vehicle electrical equipment (such as air-conditioning systems, choppers for regulating direct current, etc.), and noise / interference introduced by external systems, electromagnetic noise may be generated.

[0088] According to the present invention, the decouplers 22A of the on-vehicle device 20A and the decouplers 22B of the grounding device 20B respectively use a working frequency band between 2 MHz and 50 MHz, more preferably between 12 MHz and 30 MHz, to avoid the above-mentioned noise and interference.

[0089] The adapter 23A of the on-vehicle device 20A alternatively includes at least a pair of different types of PLC modules 25A1, 25A2 connected to a management module 26A serving as a gateway. Suitably, the PLC modules 25A1, 25A2 are adapted to send diagnostic data of the on-vehicle device 20A, especially diagnostic data regarding connection quality, to the management module 26A. As described below, the management module 26A allows for the so-called handover, that is, during the movement of the relevant vehicle 12, independent of the driving direction of the vehicle, a channel from the grounding device 20B to another grounding device. The PLC modules 25A1, 25A2 of the adapter 23A of the on-vehicle device 20A are configured as PLC slave devices.

[0090] According to the present invention, suitably, the communication between the on-vehicle device 20A and the grounding device 20B is guaranteed within a distance between 1 m and 1500 m. Therefore, an appropriate number of grounding devices 20B are provided along the transportation network 11 to ensure safe and continuous transmission.

[0091] Considering the Italian railway network, which includes lines approximately 20 km long, by arranging a grounding device 20B every 200 m along the track 13, continuous and safe communication can be ensured, and the adapter 23A of the on-vehicle device 20A of each vehicle 12 allows for handover from the grounding device 20A to the next device.

[0092] Figure 5 Schematically shows the operating mode of the transmission and decoupling system 20 for handover between a grounding device and another grounding device when the vehicle 12 is moving.

[0093] In this figure, the transmission and decoupling system 20 particularly includes four grounding devices 20B and a vehicle-mounted device 20A. Each grounding device includes a decoupler 22B and an adapter 23B, and each adapter includes a PLC module 25B and a management module 26B. The vehicle-mounted device 20A is particularly the vehicle-mounted device 20A installed on the moving vehicle 12 and displayed at different times t = t1, t = t2, and t = t3.

[0094] As previously described and Figure 5 shown, each vehicle-mounted device 20A includes a pair of PLC modules 25A1, 25A2 connected to the management module 26A.

[0095] For correct data transmission, the PLC modules of the grounding devices 20B are divided into a first type (denoted as Type 1) and a second type (denoted as Type 2), and are alternated with each other. Similarly, the vehicle-mounted device 20A includes a first PLC module of the first type and a second PLC module of the second type.

[0096] Particularly, in Figure 5 the example shown, the transmission and decoupling system 20 includes a first grounding device of the first type, denoted as Type 1-DT1-20B, a second grounding device of the second type denoted as Type1-DT3-20B, a third grounding device of the first type called Type 1-DT3-20B, and a second type of grounding device indicated as Type 2-DT4-20B.

[0097] More specifically:

[0098] - The first grounding device of the first type, Type 1-DT1-20B, includes a decoupler DT1-22B and an adapter Type 1-DT1-23B. The adapter Type 1-DT1-23B further includes a PLC module of the first type, Type1-DT1-25B, and the corresponding management module Type 1-DT1-26B;

[0099] - The second grounding device of the second type, Type 2-DT2-20B, includes a decoupler DT2-22B and an adapter Type 2-DT2-23B. The adapter Type 2-DT2-23B further includes a PLC module of the second type, Type2-DT2-25B, and the corresponding management module Type 2-DT2-26B;

[0100] - The third grounding device of the first type, Type 1-DT3-20B, includes a decoupler DT3-22B and an adapter Type 1-DT3-23B. The adapter Type 1-DT3-23B further includes a PLC module of the first type, Type1-DT3-25B, and a corresponding management module Type 1-DT3-26B;

[0101] - The fourth grounding device of the second type, Type 2-DT4-20B, includes a decoupler DT4-22B and an adapter Type 2-DT4-23B. The adapter Type 2-DT4-23B further includes a PLC module of the second type, Type2-DT4-25B, and a corresponding management module Type 2-DT4-26B.

[0102] The vehicle-mounted device 20A similarly includes a decoupler 22A and an adapter 23A. The adapter 23A further includes a first PLC module of the first type, Type 1-25A, a second PLC module of the second type, Type 2-25B, and a management module 26A.

[0103] Appropriately, the first PLC module of the first type, Type 1-25A, of the vehicle-mounted device 20A can only communicate with the modules of the grounding device 20B of the first type. In this example, the grounding device 20B of the first type is the first type of PLC module, Type 1-DT1-25B, of the first grounding device Type 1-DT1-20B and the first type of PLC module, Type 1-DT3-25B, of the third grounding device Type 1-DT3-20B. The second PLC module of the second type, Type 2-25A, of the vehicle-mounted device 20B can only communicate with the modules of the grounding device 20B of the second type. In this example, the grounding device 20B of the second type is the second type of PLC module, Type 2-DT2-25B, of the second grounding device Type2-DT2-20B and the second type of PLC module, Type 2-DT4-25B, of the fourth grounding device Type2-DT4-20B.

[0104] The grounding devices 20B are placed at intervals from each other according to distances L1, L2, L3, preferably equal to each other. Specifically, the distances are determined based on the minimum signal-to-noise ratio required as a link quality parameter for obtaining the throughput required for a specific application using this type of communication (such as voice, data, etc.), and are determined according to the type of the power supply network of the architecture 10 for data transmission (such as overhead railway or tram catenary or third-rail power supply, etc.). For example, in order to ensure a throughput of 2 Mbps for a power supply network with an overhead catenary, it can be verified that the maximum distance between two grounding devices 20B is approximately equal to 700 m. In this way, the grounding devices 20B, including the adapter 23B as the PLC master device with different types of main PLC modules 25B, alternate with each other, thereby forming a PLC network on the overhead railway or tram catenary.

[0105] More specifically, referring to Figure 5 the simplified embodiment shown, when the vehicle 12 and its on-vehicle device 20A are in a first position corresponding to a first time t = t1, the first PLC module Type 1-25A1 of the first type of the on-vehicle device 20A is only connected to the first PLC module Type 1-DT1-25B of the first type of the first grounding device Type 1-DT1-20B, which transmits a signal DT1-S11, and the signal-to-noise ratio of which is sufficient to ensure two-way data exchange between the on-vehicle device 20A and the first grounding device Type 1-DT1-20B. In particular, the communication occurs between the first PLC module Type 1-25A1 of the first type of the on-vehicle device 20A and the first PLC module Type 1-DT1-25B of the decoupler 22B connected to the first grounding device Type 1-DT1-20B.

[0106] At a second time t = t2, the first PLC module of the first type, Type 1-25A1, of the in-vehicle device 20A continues to transmit the signal DT1-S21 to the first PLC module of the first type, Type 1-DT1-25B, of the first grounding device Type 1-DT1-20B. At the time t = t2, the second PLC module of the second type, Type 2-25A2, of the in-vehicle device 20A is associated, that is, it transmits the signal DT2-S22 to the second PLC module of the second type, Type 2-DT2-25B, of the second grounding device Type 2-DT2-20B. Appropriately, according to the present invention, the two-way data transmission occurs only between the first PLC module of the first type, Type 1-25A1, of the in-vehicle device 20A and the first PLC module of the first type, Type 1-DT1-25B, of the first grounding device Type 1-DT1-20B, because only the signal-to-noise ratio of the first signal DT1-S21 is sufficient to ensure the connection with the in-vehicle device 20A and the correct two-way data transmission to the backbone Ethernet 14.

[0107] In addition, at a third time t = t3, the first PLC module of the first type, Type1-25A1, of the in-vehicle device 20A is capable of transmitting the signal DT1-S31 to the first PLC module of the first type, Type 1-DT1-25B, of the first grounding device Type 1-DT1-20B. At the time t = t3, the second PLC module of the second type, Type 2-25A2, of the in-vehicle device 20A is capable of sending the second signal DT2-S32 to the second PLC module of the second type, Type 2-DT2-25B, of the second grounding device Type 2-DT2-20B. Appropriately, according to the present invention, in this case, the two-way data transmission occurs between the second PLC module of the second type, Type2-25A2, of the in-vehicle device 20A and the second PLC module of the second type, Type2-DT2-25B, of the second grounding device Type 2-DT2-20B, because the signal-to-noise ratio of the signal DT2-S32 is sufficient to ensure the two-way data transmission with the in-vehicle device 20A and is higher than the signal-to-noise ratio of the signal DT1-S31. Thus, a handover is performed between the first grounding device Type1-DT1-20B and the second grounding device Type 2-DT2-20B.

[0108] Finally, at a fourth time t = t4, the second PLC module of the second type, Type2-25A2, of the in-vehicle device 20A is connected only to the second PLC module of the second type, Type 2-DT2-25B, of the second grounding device Type 2-DT1-20B through the signal DT2-S42, and this signal has a signal-to-noise ratio sufficient to ensure two-way data exchange with the backbone Ethernet 14.

[0109] It should be emphasized that the slave PLC modules 25A1 and 25A2 of the adapter 23A of the in-vehicle device 20A can be directly connected to the master PLC module 25B of the adapter 23B of the ground device 20B according to the alternation of their types, without the need to provide any type of repeater.

[0110] Essentially, the in-vehicle device 20A will verify the connection signals between the reachable ground devices 20B at any time and select the device with a signal-to-noise ratio sufficient for data transmission.

[0111] It should be noted that according to the present invention, how the architecture 10 for data transmission can advantageously ensure continuous and secure transmission between the vehicle 12 and the backbone Ethernet 14, and thus can be used to transmit any type of data, especially:

[0112] - Critical data, that is, the data necessary for the normal operation of the vehicle, such as console driver data, motor control data, brake control data, track signals, power electronics signals, safety signals, etc.;

[0113] - Non-critical data, that is, the data not necessary for the normal operation of the vehicle, but related to the better comfort of the on-vehicle passengers, such as passenger information, vehicle diagnostic data, audio-visual entertainment signals.

[0114] In addition, the PLC modules of the adapters 23A and 23B can exchange diagnostic data related to the connection quality with the management modules 26A and 26B to allow handover between the ground devices 20B, especially between one master PLC module 25B and another master PLC module 25B, especially using the signal-to-noise ratio as the link quality parameter, as described above.

[0115] Advantageously, according to the present invention, the handover mechanism can also be associated with additional link quality parameters provided to the management modules 26A and 26B. For example, the connection between the in-vehicle device and the ground device can also be based on:

[0116] - The authentication status of the master PLC module and / or the slave PLC module;

[0117] - The RSSI (Received Signal Strength Indication) of a special signal called a beacon frame between the master PLC module and the slave PLC module;

[0118] - The AGC (Automatic Gain Control) on the so-called RxPGA (i.e., the programmable gain amplifier of the receiver) is used to compensate for the amplitude of the signal received from the receiver; and

[0119] - Based on the physical data rate of dynamically exchanging data on the estimated channel between the master PLC module and the slave PLC module, which is a variable parameter based on the transmission conditions.

[0120] According to another embodiment, several handover rules can be used to drive the handover mechanism, in particular:

[0121] - The evaluation time of the link quality parameter;

[0122] - The time between two scans, i.e., the frequency of retrieving information and roaming estimation from the slave module of the grounded device 20B (e.g., 250 ms);

[0123] - No return latency, i.e., the minimum latency before returning to the used master module; and

[0124] - The smoothing factor, i.e., the weighted importance of the latest signal and the old signal.

[0125] Different combinations of the above handover rules can be used according to the application field, especially when the architecture is used in railways or trams or any other possible scenarios.

[0126] It should also be noted that the handover mechanism at the grounded device 20B of the proposed architecture is a two-level conversion mechanism, where two master modules are simultaneously connected to two on-vehicle PLC modules, and the active communication channel is switched between the on-vehicle PLC modules at level 2 of the ISO / OSI stack.

[0127] In summary, according to the present invention, advantageously, due to the use of the BPLC communication mode (Broadband over Power Line Communication), the architecture of data transmission allows the use of the power supply line that transmits the electric traction energy to the vehicles circulating in the transportation network, so as to establish a two-way connection between the vehicle and the remote control center.

[0128] Suitably, the architecture for data transmission according to the present invention has a low installation cost because it does not require additional antennas, and has a low maintenance cost due to the use of components (decouplers, adapters) with a high average interruption time.

[0129] The energy-saving effect that can be obtained by the architecture for data transmission according to the present invention is extremely significant. For example, considering that there is only an underground line 20 km long consisting of 20 stations and 22 trains, the energy consumption of the currently implemented solution is equal to 21.19 KW, and this solution requires a transmission box with an antenna to be installed every 400 m and uses Wi-Fi radio transmission on the train. While for the architecture for data transmission using the BPLC communication mode, a grounded device is installed every 700 m and on-vehicle radio transmission is carried out, and its energy consumption is equal to 1.15 KW, that is, the energy saving is 94.5%.

[0130] Finally, it should be noted that, advantageously, according to the present invention, the proposed architecture for data transmission has high scalability because it can be expanded according to the requirements of the transportation network infrastructure, and thus can grow in proportion to the scale and coverage requirements.

[0131] Obviously, those skilled in the art will be able to make various modifications and variations to the above architecture in order to meet accidental and specific requirements, and all such modifications and variations are included within the scope of protection of the present invention defined by the following claims.

Claims

1. An architecture (10) for data transmission between a plurality of electric traction vehicles (12) moving in a transportation network (11) and a backbone Ethernet (14), the transportation network (11) including a plurality of substations (15), the substations (15) being connected to a low / medium voltage power supply network (16) of the vehicles (12), characterized in that, The power supply network (16) is used to perform continuous data transmission on the vehicle (12) and the backbone Ethernet (14) according to the BPLC communication mode through a transmission and decoupling system (20). The transmission and decoupling system (20) is inserted between the vehicle (12) and the substation (15) connected to the power supply network (16). The transmission and decoupling system (20) includes: - On-vehicle equipment (20A), which is adapted to be placed on each vehicle (12); and - A plurality of grounding devices (20B), each of the grounding devices (20B) being adapted to be coupled to at least one of the substations (15). When the vehicle (12) passes by one of the grounding devices (20B) among the grounding devices (20B), the on-vehicle equipment (20A) can be connected to the corresponding grounding device (20B). Wherein, Each of the grounding devices (20B) includes at least an adapter (23B). The adapter (23B) is directly connected to the backbone Ethernet (14) and is a PLC master device; and The on-vehicle equipment (20A) of each vehicle (12) includes an adapter (23A) as a PLC slave device.

2. The architecture (10) for data transmission according to claim 1, characterized in that, The on-vehicle equipment (20A) is connected to the grounding device (20B) based on a signal-to-noise ratio suitable for ensuring two-way communication with the backbone Ethernet (14).

3. The architecture (10) for data transmission according to claim 2, characterized in that, The on-vehicle equipment (20A) is connected to the grounding device (20B) based on additional link quality parameters selected from the following: the authentication status of the master PLC module and / or the slave PLC module, the received signal strength indication RSSI of the beacon frame between the master PLC module and the slave PLC module, the automatic gain control AGC on the programmable gain amplifier RxPGA of the receiver, and the physical data rate based on the dynamic exchange of data on the estimated channel between the master PLC module and the slave PLC module. The automatic gain control AGC is used to compensate for the amplitude of the signal received from the receiver.

4. The architecture (10) for data transmission according to claim 1, characterized in that, The adapter (23A) includes at least a first PLC module (Type 1-25A1) of the first type and a second PLC module (Type 2-25A2) of the second type. The first PLC module of the first type and the second PLC module of the second type are connected to a management module (26A) serving as a gateway. The adapter (23A) is adapted to convert digital data into an analog radio frequency signal, connect to the low / medium voltage local power supply line (17) of the vehicle (12), and connect to the grounding device (20B) when connected to the said on-vehicle equipment (20A).

5. The architecture (10) for data transmission according to claim 4, characterized in that, The in-vehicle device (20A) of each vehicle (12) further includes a decoupler (22A) adapted to eliminate the continuous component of the supply voltage on the local supply line (17) and to provide a high-pass filter to eliminate low-frequency noise in the input signal and to obtain an information signal to be transmitted to the ground device (20B) when connected to the in-vehicle device (20A), thereby enabling connection to the supply network (16) and data transmission to the backbone Ethernet (14) according to the BPLC communication mode.

6. The architecture (10) for data transmission according to claim 1, characterized in that, The in-vehicle device (20A) is connected to the local network (21) of the vehicle (12).

7. The architecture (10) for data transmission according to claim 3, characterized in that, The architecture (10) for data transmission includes a plurality of first-type ground devices (Type1-DT1-20B, Type 1-DT3-20B) and a plurality of second-type ground devices (Type 2-DT2-20B, Type 2-DT4-20B) that are alternating and spaced apart from each other according to distances (L1, L2, L3).

8. The architecture (10) for data transmission according to claim 7, characterized in that, Each of the first-type ground devices (Type 1-DT1-20B, Type 1-DT3-20B) includes at least one adapter (Type 1-DT1-23B, Type 1-DT3-23B), and the at least one adapter (Type1-DT1-23B, Type 1-DT3-23B) further includes a first-type PLC module (Type 1-DT1-25B, Type 1-DT3-25B) and a corresponding management module (Type 1-DT1-26B, Type 1-DT3-26B), and the management module (Type 1-DT1-26B, Type 1-DT3-26B) is capable of connecting to the first-type first PLC module (Type 1-25A1) of the adapter (23A) of the in-vehicle device (20A); and each of the second-type ground devices (Type 2-DT2-20B, Type 2-DT4-20B) includes at least one adapter (Type 2-DT2-23B, Type 2-DT4-23B), and the at least one adapter (Type 2-DT2-23B, Type 2-DT4-23B) further includes a second-type PLC module (Type2-DT2-25B, Type 2-DT4-25B) and a corresponding management module (Type 2-DT2-26B, Type2-DT4-26B), and the management module (Type 2-DT2-26B, Type 2-DT4-26B) is capable of connecting to the second-type second PLC module (Type2-25A2) of the adapter (23A) of the in-vehicle device (20A).

9. The architecture (10) for data transmission according to claim 8, characterized in that The grounding devices of the first type (Type 1-DT1-20B, Type 1-DT3-20B) and the grounding devices of the second type (Type 2-DT2-20B, Type 2-DT4-20B) respectively include management modules (Type 1-DT1-26B, Type1-DT3-26B; Type 2-DT2-26B, Type 2-DT4-26B) connected to the PLC modules of the first type (Type 1-DT1-25B, Type 1-DT3-25B) and the PLC modules of the second type (Type 2-DT2-25B, Type 2-DT4-25B).

10. The architecture (10) for data transmission according to claim 7, characterized in that, Each of the grounding devices (20B) includes a decoupler (22B) which is adapted to eliminate the continuous component from the supply voltage, provide a high-pass filter to eliminate the low-frequency noise in the input signal, and obtain the information signal to be transmitted to the vehicle-mounted device (20A).

11. The architecture (10) for data transmission according to claim 1, characterized in that, The substation (15) is selected from: railway or tramway track stations, railway or tramway track stops, substations of railway or tramway track networks, and other structures located along railway or tramway track lines.

12. The architecture (10) for data transmission according to claim 1, characterized in that, The vehicle is selected from trains, trolleybuses, trams and other electric traction transport vehicles.

13. The architecture (10) for data transmission according to claim 1, characterized in that, The grounding device (20B) is placed at a distance of 1 m to 1500 m from the vehicle-mounted device (20A) of the vehicle (12).

14. The architecture (10) for data transmission according to any one of the preceding claims, characterized in that, The architecture (10) for data transmission performs the handover of data from the grounding device (20B) to the next grounding device by verifying the minimum value of the signal-to-noise ratio transmitted between the grounding device (20B) and the vehicle-mounted device (20A).

15. The architecture (10) for data transmission according to any one of the preceding claims, characterized in that, The architecture (10) for data transmission transmits: - Critical data which is necessary for the vehicle (12) and the transport network (11) to work properly as a whole; and - Non-critical data which is related to improving the passenger comfort on the vehicle (12).

16. A method for continuous data transmission in the architecture according to any one of the preceding claims, wherein the grounding devices (20B) are divided into a first type and a second type and are alternated with each other between the first type and the second type, and each device type is adapted to be connected to a different module of the vehicle-mounted device (20A), the method comprising the following steps: Transmitting signals from each of the modules of the vehicle-mounted device (20A) to the grounding devices (20B) of the same type; Verifying the signal-to-noise ratio value of the transmitted signals as a link quality parameter; Selecting the signal with the maximum signal-to-noise ratio value among the transmitted signals; And Connecting one of the modules of the vehicle-mounted device (20A) to one of the grounding devices (20B) corresponding to the signal with the maximum signal-to-noise ratio value, Repeating the above steps during the following time when the vehicle (12) is moving to ensure the continuous data transmission.

17. The method for continuous data transmission according to claim 16, wherein, Use additional link quality parameters to evaluate a grounding device (20B) of one of the modules to be connected to the in-vehicle device (20A).

18. The method for continuous data transmission according to claim 17, wherein, The additional link quality parameters are selected from: the authentication status of the master PLC module and / or the slave PLC module, the received signal strength indication RSSI of beacon frames between the master PLC module and the slave PLC module, the automatic gain control AGC on the programmable gain amplifier RxPGA of the receiver, and the physical data rate based on dynamically exchanging data on the estimated channel between the master PLC module and the slave PLC module, where the automatic gain control AGC is used to compensate for the amplitude of the signal received from the receiver.

19. The method for continuous data transmission according to claim 18, wherein, Use multiple handover rules to drive the following handover mechanism: - The evaluation time of the link quality parameter; - The time between two scans, which is the frequency of retrieving information and roaming estimation from the slave module of the grounding device (20B); - The no-return delay, which is the minimum delay before returning to the used master module; and - The smoothing factor, which is the weighted importance of the latest signal and the old signal.

20. The method for continuous data transmission according to claim 19, wherein, Use different combinations of the handover rules and the additional link quality parameters based on the application scenario.

Images