SE2350325A1

SE2350325A1 - Central buffer coupler, signal transceiver, vehicle member and computer-implemented method

Info

Publication number: SE2350325A1
Application number: SE2350325A
Authority: SE
Inventors: Johan Åhman; Johan Åkerberg; Lennart Liljeström; Thilo Koch
Original assignee: Dellner Couplers Ab
Priority date: 2023-03-23
Filing date: 2023-03-23
Publication date: 2024-03-26
Also published as: SE545948C2; WO2024193867A1

Abstract

A central buffer coupler has a first coupling head adapted to be mounted on a first vehicle member of a multi-member vehicle. The first coupling head contains a first signal transceiver (100) for communicating with a second signal transceiver (200) on a second coupling head mounted on a second vehicle member of the multi-member vehicle. When the first and second coupling heads are mechanically interconnected, the first and second signal transceivers (100; 200) are positioned facing one another in a physically matching manner, such that respective microwave transmitters (111, 211) and receivers (121, 221) therein face one another in an interface-module-pair (151, 251) with a first waveguide transmitter antenna (131) of a first microwave transmitter (111) in the first signal transceiver (100) physically matching a second waveguide receiver antenna (232) presumed to be communicatively connected to a second microwave receiver (221) in the second signal transceiver (200). Analogously, a first waveguide receiver antenna (132) of a first microwave receiver (121) in the first signal transceiver (100) physically matches a second waveguide transmitter antenna (231) presumed to be communicatively connected to a second microwave transmitter (211) in the at least one second signal transceiver (200).

Description

TECHNICAL FIELD The invention relates generally to communication of signals, messages and data between vehicle members in multi-member vehicles, such as the railroad cars of a train. ln particular, the present invention concerns a central buffer coupler according to the preamble of claim 1. The invention also pertains to a signal transceiver included in the central buffer coupler and a vehicle member carrying the central buffer coupler. Additionally, the in- vention encompasses a software-implemented method applied in respect of the proposed signal transceiver.

BACKGROUND For safe and reliable operation of railway trains it is key that commands, status messages and signals may be communicated bi-directionally without disruptions between the railroad cars in the train.

For example, GB 2 450 520 shows a communication system for transferring communication within a railway train that comprises a data bus adapted to transfer data according to the Internet Protocol via point-to-point connections. Devices are connected to the data bus, wherein the devices are adapted to receive and/or send safety-relevant data (e.g. braking, door control) via the data bus. The data bus may be in a ring featuring ring switches, allowing data to be sent along multiple paths, and such rings in each carriage or group of carriages are connected to a backbone bus running throughout the train, and connected via train switches.

For efficiency reasons, it is further important that railroad cars may be coupled to and decoupled from a train in a convenient manner while ensuring continued communication between the railroad cars contained in the train before and after the coupling/ decoupling respectively.

Due to the harsh environment where the couplers are located it may be advantageous to avoid galvanic connectors at the inter- face between the different railroad cars. US 8,985,356 describes one example of an electric coupling for railways that contains a first and a second coupling part each comprising a support in which a plurality of linking parts are arranged for establishing an electric, pneumatic and/or hydraulic link from one coupling part to another coupling part. ln addition, at least one high-frequency link is provided which is formed by an enclosed antenna in one coupling part and by an enclosed antenna in the other coupling part.

WO 2007/079501 discloses another contactless data communi- cation coupler. Here, a non-contact data connection is provided that is adaptable to transmit data across an air gap. The data connection includes a first substrate and a loosely coupled wide band pulse transformer for transmitting data over an air gap se- parating a primary winding from a secondary winding of the transformer. The primary winding of the transformer includes at least two planar windings formed in parallel planes upon and/or within the first substrate for facilitating a neutralization of trans- mission line resonances due to distributed capacitance and in- ductance of the planar windings.

US 2007 /0054562 reveals an automatic central buffer coupling for a multi-membered vehicle, in particular a rail-borne vehicle, having a coupling head and a signal transmission device for transmitting electric and/or receiving electronic signals between a first and a second car body. A signal transmission device is integrated in the central buffer coupling, which on the one hand is designed to be rugged and compact and, on the other, is ba- sed on a system as free as possible from attrition and mainte- nance. The signal transmission device is provided in the central buffer coupling with at least one coupling element and at least one counter-coupling element. The coupling element is integrated in a contact plate of a coupling head of the coupling and the counter-coupling element is integrated in a contact plate of coupling head of the counter-coupling, such that the face side of the coupling element is arranged opposite the face side of the counter-coupling element integrated in coupling head of the counter-coupling in the contact plane of coupling heads. The coupling element and the counter-coupling element each has an antenna member comprising a disc monopole antenna configured to transmit data in the GHz frequency range.

Thus, solutions exist for contactless exchange of commands, status messages, signals etc. between the railroad cars in a train. However, todays' train operators demand that data be communicated at even higher bitrates than what is possible via the above-described designs. At the same time, communication interfaces shall be robust and cost-efficient to implement.

SUMMARY One object of the present invention is therefore to offer a solu- tion that solves the above problems and enables wireless and bi-directional data communication between railroad cars at mul- tiple gigabits per second, and which is implementable by means of resilient and uncomplicated components.

According to one aspect of the invention, the object is achieved by a central buffer coupler for a multi-member vehicle, which central buffer coupler contains a first coupling head adapted to be mounted on a first vehicle member of the multi-member ve- hicle. The first coupling head, in turn, includes at least one first signal transceiver and a coupling element configured to connect mechanically to a counter-coupling element of a second coup- ling head mounted on a second vehicle member of the multi- member vehicle. The second coupling head is presumed to con- tain at least one second signal transceiver that is arranged such that the at least one first and second signal transceivers are po- sitioned facing one another in a physically matching manner when the coupling element is mechanically connected to the counter-coupling element. The at least one first signal transcei- ver includes at least one microwave transmitter and at least one microwave receiver, which, when the coupling element is me- chanically connected to the counter-coupling element are arran- ged such that in at least one first interface-module-pair at least one first waveguide transmitter antenna of at least one first mi- crowave transmitter of the at least one first signal transceiver physically matches at least one second waveguide receiver an- tenna presumed to be communicatively connected to at least one second microwave receiver of the at least one second sig- nal transceiver. Analogously, when the coupling element is me- chanically connected to the counter-coupling element, at least one first waveguide receiver antenna of at least one first micro- wave receiver in the at least one first signal transceiver phy- sically matches at least one second waveguide transmitter an- tenna presumed to be communicatively connected to at least one second microwave transmitter in the at least one second signal transceiver.

This central buffer coupler is advantageous because it enables bi-directional transmission of data between for example railroad cars at very high bitrates and low risk of signal deterioration due to spurious emissions or intermodulation distortion.

According to one embodiment of this aspect of the invention, each of the at least one interface-module-pair contains at least one shielding wall member configured to prevent leakage of electromagnetic radiation from the at least one first and second signal transceivers during operation thereof. Thus, undesired spurious emissions may be reduced even further.

According to another embodiment of this aspect of the invention, the at least one first signal transceiver is comprised in a first communication unit, and the at least one second signal transcei- ver is presumed to be comprised in a second communication unit. The first communication unit has a first front side arranged to face a second front side presumed to be comprised in the second communication unit. Further, at least one of the first and second front sides contains at least one projecting element con- figured to be received by at least one matching recess in an op- posite one of the at least one of the first and second front sides when the first coupling head is mechanically connected to the second coupling head. Thereby, it can be ensured that the at least one first waveguide transmitter antenna is arranged such that it physically matches the at least one second waveguide receiver antenna, and the at least one first waveguide receiver antenna physically matches the at least one second waveguide transmitter antenna. As a result, duplex communication at com- paratively low transmission losses is attainable. lt is further advantageous if each of the first and second front si- des further includes at least one respective electrical coupler configured to transfer electric power between the first and se- cond vehicle members, which at least one respective electrical coupler likewise is arranged to physically match one another. Hence, it is straightforward to feed electric power between dif- ferent vehicle members, e.g. railroad cars, should this be neces- sary during operation of the multi-member vehicle.

According to yet another embodiment of this aspect of the inven- tion, the first communication unit has a cover, which is configu- red to be selectively arranged in a first or a second position. ln the first position, the at least one first waveguide transmitter an- tenna and the at least one first waveguide receiver antenna are physically screened-off by the cover, i.e. the antennas are me- chanically protected and cannot operate. ln the second position, however, the at least one first waveguide transmitter antenna and the at least one first waveguide receiver antenna are expo- sed for potential exchange of signals with the at least one se- cond waveguide receiver antenna and the second at least one transmitter antenna respectively. The first signal transceiver is further configured to: cause the at least one first microwave transmitter to emit a probe signal, check a reception property of the probe signal via the at least one first microwave receiver, and based thereon determine whether the cover is arranged in the first or second position. Consequently, the first signal trans- ceiver may verify that it is mechanically prepared to be connec- ted to the second signal transceiver before proceeding to do so.

According to still another embodiment of this aspect of the in- vention, the at least one first signal transceiver contains a first modem configured to transform incoming packet data messages from the first vehicle member into output microwave signals for transmission through the at least one first microwave transmit- ter, and transform microwave signals received via the at least one first microwave receiver into output packet data messages to the first vehicle member. Thus, full duplex communication may be executed via the at least one first signal transceiver as- suming that it is connected to at least one second signal trans- ceiver in another vehicle member.

Preferably, the first modem is configured to communicate the packet data messages on an Ethernet format via at least one data bus carried by at least one twisted-pair cable, at least one of at least one coaxial cable and/or at least one optical fiber. Thereby, it is convenient to exchange commands, signals, sta- tuses etc. between the first vehicle member and other vehicle members. lt is also advantageous if the first modem is configured to com- municate the packet data messages while fulfilling traffic prioriti- zation and resource reservation control mechanisms according to a Quality-of-Service standard. Namely, thereby messages, commands, signals etc. of different degrees of criticality may be exchanged in parallel over the first modem whilst ensuring that the most important ones are duly delivered.

According to yet another embodiment of this aspect of the in- vention, the first modem is configured to be communicatively connected to one or more full-duplex microwave transceiver modules, which each contains a pair of the at least one first mi- crowave transmitter and the at least one second microwave re- ceiver respectively. This is advantageous because it facilitates expanding the bandwidth of the first signal transceiver by quanta equivalent to the communication capacity of one of said modu- les.

Namely, preferably, each of the one or more full-duplex micro- wave transceiver modules is configured to handle bi-directional data traffic at a particular bitrate, say 6 to 10 Gbit/s.

According to still another embodiment of this aspect of the in- vention, each of the at least one first waveguide transmitter an- tenna includes a respective horn antenna, and each of the at least one first waveguide receiver antenna includes a respective horn antenna. Thereby, it is rendered relatively straightforward to match the at least one first waveguide transmitter antenna physically to the at least one first waveguide receiver antenna at an overall low degree of signal losses. lt is further preferable if each of the at least one first waveguide transmitter antenna and each of the at least one first waveguide receiver antenna is covered by a sealing membrane configured to exclusively allow a unidirectional passage of moisture out from the first and second signal transceivers respectively; and/ or the first signal transceiver is provided with a drainage system. Alternatively, the first signal transceiver may be enclosed in a moisture-protective substance, or be covered by a moisture-pro- tective coating.

According to other aspects of the invention, the object is achie- ved by a signal transceiver comprised in the proposed central buffer coupler and a vehicle member respectively configured to form part of a multi-member vehicle, which vehicle member con- tains the proposed central buffer coupler. The advantages of such signal transceiver and vehicle member, as well as the pre- ferred embodiments thereof, are apparent from the discussion above with reference to the proposed central buffer coupler.

According to yet another aspect of the invention, the object is achieved by a computer-implemented method, which involves the steps of: controlling at least one first microwave transmitter to emit a probe signal, which at least one first microwave transmitter is comprised in a first signal transceiver of a first coupling head mounted on a first vehicle member of a multi-member vehicle; controlling at least one first microwave receiver to check a reception property of the probe signal, which at least one first microwave receiver is comprised in the first signal transceiver; and based thereon determining whether a cover is arranged in: a first position in which at least one first waveguide transmitter antenna of the at least one first microwave transmitter and at least one first waveguide receiver anten- na of the at least one first microwave receiver are physi- cally screened-off by the cover, or a second position in which the cover exposes the at least one first waveguide transmitter antenna and the at least one first waveguide receiver antenna for potential signal exchange with at least one second waveguide recei- ver antenna and at least one second at least one transmit- ter antenna respectively comprised in a second signal transceiver of a second coupling head mounted on a se- cond vehicle member of the multi-member vehicle.

Only if the cover is determined to be arranged in the second po- sition the at least one first microwave transmitter and the at least one first microwave receiver are enabled to operate in a communication mode.

Consequently, it can be verified that the first signal transceiver is mechanically prepared to be connected to the second signal transceiver before proceeding to connect the first signal trans- ceiver to the second signal transceiver.

Further advantages, beneficial features and applications of the present invention will be apparent from the following description and the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is now to be explained more closely by means of preferred embodiments, which are disclosed as examples, and with reference to the attached drawings.

Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 shows a block diagram of first and second sig- nal transceivers according to a first embodi- ment of the invention; shows a side view of the first signal transcei- ver according to the first embodiment of the in- venüon; shows a block diagram of first and second sig- nal transceivers according to a second embo- diment of the invention; shows a perspective view of the first signal transceiver according to the second embodi- ment of the invention; shows a side view of the first signal transcei- ver according to the first embodiment of the in- venüon; shows a perspective view of a central buffer coupler according to one embodiment of the invenüon; shows a perspective view of a first communi- cation unit according to one embodiment of the invenüon; exemplifies how a cover may be arranged on first communication unit according to one em- bodiment of the invention; and Figure 9 illustrates, by means of a flow diagram, a com- puter-implemented method applied in respect of the cover shown in Figure 8.

DETAILED DESCRIPTION Figure 1 shows a block diagram of first and second signal trans- ceivers 100 and 200 respectively according to a first embodi- ment of the invention, and Figure 2 shows a side view of the first signal transceiver 100 according this embodiment. lt is presumed that the of first signal transceiver 100 is included in a central buffer coupler 600, for example as illustrated in Fi- gure 6, and the second signal transceiver 200 is included in another central buffer coupler that is mechanically connected to the first signal transceiver 100. Specifically, according to the in- vention, the central buffer coupler 600 and its mechanical coun- terpart are adapted to be comprised in a multi-member vehicle, e.g. a train, where the central buffer coupler 600 is arranged on a first vehicle member, e.g. a first railroad car, and the mechani- cal counterpart is arranged on a second vehicle member, e.g. a second railroad car.

The central buffer coupler 600, in turn, includes a first coupling head 610 adapted to be mounted on the first vehicle member. As will be discussed below with reference to Figure 7, the first coupling head 610 contains at least one instance of the first signal transceiver 100. The first coupling head 610 also contains a coupling element 611 configured to connect mechanically to a counter-coupling element of the second coupling head that is mounted on the second vehicle member of the multi-member vehicle. Here, the second coupling head is presumed to include at least one instance of the second signal transceiver 200, which is arranged such that the at least one first and second signal transceivers 100 and 200 respectively are positioned fa- cing one another in a physically matching manner when the 11 coupling element 611 is mechanically connected to the counter- coupling element. ln the first embodiment of the invention, the first signal trans- ceiver 100 contains one microwave transmitter 111 and one mi- crowave receiver 121, which, when the coupling element 611 is mechanically connected to the counter-coupling element are ar- ranged such that in a first interface-module-pair 151/251 a first waveguide transmitter antenna 131 of the first microwave trans- mitter 111 physically matches a second waveguide receiver an- tenna 232 presumed to be communicatively connected to a se- cond microwave receiver 221 of the at least one second signal transceiver 200. Analogously, a first waveguide receiver an- tenna 132 of the first microwave receiver 121 of the first signal transceiver 100 physically matches a second waveguide trans- mitter antenna 231 presumed to be communicatively connected to a second microwave transmitter 211 of the second signal transceiver 200. The microwave transmitters and receivers 111, 211, 121 and 222 may be configured to operate in the 60 GHz range.

The microwave transmitter 111 and the microwave receiver 121 are organized in a first full-duplex microwave transceiver module 181, and the microwave transmitter 211 and the microwave receiver 221 are organized in a second full-duplex microwave transceiver module 281. Preferably, for efficient usage of the re- sources, each of the first and second transceiver modules 181 and 281 is configured handle bi-directional data traffic of the sa- me bitrate, for example 6 Gbit/s or more.

According to one embodiment of the invention, the interface-mo- dule-pair 151/251 includes at least one set of shielding wall members that is configured to prevent leakage of electromagne- tic radiation from the first and second signal transceivers 100 and 200 during operation thereof. For example, a first set of shielding wall members may be arranged around the first wave- guide transmitter antenna 131 and the first waveguide receiver 12 antenna 132, and a second set of shielding wall members may be arranged around the second waveguide receiver antenna 232 and the second waveguide transmitter antenna 231 as illustrated in Figures 1 and 2. Another example of how the shielding wall members may be arranged will be described below with referen- ce to Figures 3 to 5 and 7.

According to one embodiment of the invention, the first signal transceiver 100 contains a first modem 110 that is configured to transform incoming packet data messages from the first vehicle member into output microwave signals MW1 for transmission through the first microwave transmitter 111. The first modem 110 is further configured to transform microwave signals MW2 received via the first microwave receiver 121 into output packet data messages to the first vehicle member. For instance, the incoming and output packet data messages may be communica- ted via one or more data busses B11, B12, B1n in the first vehicle member.

Analogously, the second signal transceiver 200 contains a se- cond modem 210 configured to transform incoming packet data messages from the second vehicle member into output micro- wave signals MW2 for transmission through the second mic- rowave transmitter 211, and transform microwave signals MW1 received via the second microwave receiver 221 into output packet data messages to the second vehicle member, which in- coming and output packet data messages may be communicated via one or more data busses B21, B22, B2n in the second vehicle member. lf the data busses B11, B12, B1n and B21, B22, B2n are implemented by means of at least one twisted-pair cable, a com- munication protocol of an Ethernet format may be employed, such as 10BaseT/802.3i, 100BaseTX/802.3u, 1000BaseT/ 802.3ab or 10GBaseT/802.3an depending on the bandwidth re- quirements. lf the data busses B11, B12, B1n and B21, B22, B2n are implemented by means of at least one coaxial cable, 13 an Ethernet format-protocol, such as 10Base5/802.3 or 10Base2/802.3a may instead be employed. For extremely high bitrates, one or more optical fibers may be used to implement the data busses B11, B12, B1n and B21, B22, B2n. lrrespective of the specific protocols and/or media used, the first and second modems 110 and 210 are preferably configured to communicate the packet data messages while fulfilling traffic prioritization and resource reservation control mechanisms ac- cording to a Quality-of-Service standard. Namely, this makes it possible to guarantee that the commands, control signals, status messages etc. being critical for the operation of the multi-mem- ber vehicle, e.g. relating to brake control, are duly communica- ted, whereas less important data, e.g. relating to an onboard in- fotainment system are allowed to be delayed or lost.

For example, each of the data busses B11, B12, B1n and B21, B22, B2n respectively may be configured to carry data traffic of a particular priority class. Specifically, this may involve communicating data traffic of a highest priority via the data bus B11 in the first vehicle member and forwarding this data traffic to the data bus B21 in the second vehicle member. ln connec- tion with that the data packets leave the second modem 210, however, the priority indication may be removed, so that the communication remains transparent to a higher-layer applica- tion. Further, the data busses B12, B1n and B22, B2n may be employed to carry data traffic of lower priorities, e.g. image/video data from onboard cameras, infotainment data and/ or various sensor data. Such differentiation in priority levels ma- kes it possible to schedule the data traffic through the respecti- ve pairs of first and second modems 110 and 210 so that the overall requirements for a network, inter alia representing the entire multi-member vehicle can be met in terms of latencies, availability and/or redundancy.

Alternatively, no priority levels are linked to the data busses B11, B12, B1n and B21, B22, B2n. lnstead, all data bus- 14 ses B11, B12, B1n and B21, B22, B2n constitute a com- mon resource free to utilize by a traffic handling algorithm ope- rating based on priority levels already assigned to each of the data packets being communicated here. ln such a case, the number of full-duplex microwave transceiver modules and data buses required is simply a matter of matching a bandwidth/capa- city need.

Naturally, according to the invention, it is also possible to com- bine the above two traffic-handling principles with one another.

Figure 2 shows a projecting element 171 of the first signal trans- ceiver 100, which projecting element 171 is configured to be re- ceived by a matching recess in the second signal transceiver 200 so as to facilitate steering the first and second signal trans- ceivers 100 and 200 into mechanical contact with one another. Preferably, each of the first and second signal transceivers 100 and 200 has a respective one of the projecting element and the matching recess, and Figure 2 exemplifies the matching recess of the first signal transceiver by reference numeral 172. Further, the projecting element 171 and the matching recess 172 may be configured to transfer electric power between the first and se- cond signal transceivers 100 and 200.

Figure 3 shows a block diagram of a second embodiment of the first and second transceivers 100 and 200 respectively. Here, all reference numeral that also occur in any of Figures 1 or 2 desig- nate the same entities and signals as described above with refe- rence to Figures 1 and 2. ln the second embodiment, the first transceiver 100 contains two full-duplex microwave transceiver modules 181 and 182 and the second transceiver 200 contains two full-duplex microwave transceiver modules 281 and 282.

Each of the transceiver modules 181 and 182 contains a res- pective microwave transmitter 111 and 112 and a respective mi- crowave receiver 121 and 122. Thus, provided that each of the full-duplex microwave transceiver modules 181, 182, 281 and 282 is configured to handle bi-directional data traffic at a par- ticular bitrate the communication bandwidth between the first and second transceivers 100 and 200 is potentially doubled. The number of data busses B11, B12, B1m and B21, B22, B2m may or may not be the same as the number of data busses used in the above-described first embodiment of the invention When the coupling element 611 of the first vehicle member is mechanically connected to the counter-coupling element of the second vehicle member, the transceiver modules 181, 182, 281 and 282 are preferably arranged relative to one another such that a first interface-module-pair 151/251 prevents leakage of electromagnetic radiation from the transceiver modules 181 and 281 and a second interface-module-pair 152/ 252 prevents lea- kage of electromagnetic radiation from the transceiver modules 182 and 282. Figures 4 and 5 illustrate how the first and second interface-module-pairs 151/251 and 152/ 252 may be designed according to one embodiment of the invention.

Here, a first set of shielding wall members 151a, 151b and 151c is arranged around the first waveguide transmitter antenna 131 and the first waveguide receiver antenna 132 of the transceiver module 181 in the first signal transceiver 100 that forms part of the first interface-module-pair 151/251. Similarly, a second set of shielding wall members 152a, 152b, 152c is arranged around the second waveguide transmitter antenna 141 and the second waveguide receiver antenna 142 of the transceiver module 182 in the first signal transceiver 100 that forms part of the second interface-module-pair 152/252. Although not illustrated, corresponding sets of shielding wall members are of course also arranged around the first and second transmitter and receiver antennas 231, 232, 241 and 242 of the second signal transceiver 200. The shielding wall members 151a, 151b, 151c, 152a, 152b and 152c are configured to prevent leakage of elec- tromagnetic radiation from the at least one first and second sig- nal transceivers 100 and 200 during operation of these units. 16 Further, analogous to the first embodiment of the invention des- cribed above with reference to Figures 1 and 2, in the second embodiment of Figure 3, transmitter and receiver waveguide antennas of the first signal transceiver 100 are arranged to phy- sically match the receiver and transmitter waveguide antennas of the second signal transceiver 200. ln Figure 3, however, the first signal transceiver 100 contains two full-duplex microwave transceiver modules 181 and 182 and the second signal trans- ceiver 200 contains two full-duplex microwave transceiver mo- dules 281 and 282. This means that a waveguide transmitter an- tenna 131 of the full-duplex microwave transceiver module 181 in the first signal transceiver 100 physically matches a wavegui- de receiver antenna 232 of the full-duplex microwave transcei- ver module 182 in the second signal transceiver 200, a wavegui- de transmitter antenna 141 of the full-duplex microwave trans- ceiver module 182 in the first signal transceiver 100 physically matches a waveguide receiver antenna 242 of the full-duplex microwave transceiver module 182 in the second signal trans- ceiver 200, a waveguide transmitter antenna 231 of the full- duplex microwave transceiver module 281 in the second signal transceiver 200 physically matches a waveguide receiver anten- na 132 of the full-duplex microwave transceiver module 181 in the first signal transceiver 100, and a waveguide transmitter an- tenna 241 of the full-duplex microwave transceiver module 282 in the second signal transceiver 200 physically matches a wave- guide receiver antenna 142 of the full-duplex microwave trans- ceiver module 182 in the first signal transceiver 100.

According to one embodiment of the invention, at least one of the waveguide transmitter antennas 131 and 141 includes a res- pective horn antenna, and at least one of the waveguide receiver antennas 132 and 142 includes a respective horn an- tenna.

For example, these horn antennas may be designed according to EP 3 547 449, which shows a wireless communication device comprising: a printed circuit board (PCB) with a dielectric sup- 17 port and electrically conductive tracks separated by the dielec- tric support and at least one horn antenna. The horn antenna is a surface-mounted component via flanges supported by the PCB and fixed on the latter. The horn antenna is arranged with the waveguide and the radiating opening on either side of the PCB and with each rib in direct contact or close to a track of the PCB, so as to allow a direct connection or a capacitive coupling bet- ween them.

Referring now to Figures 1 and 3, the waveguide transmitter an- tennas 131 and 141 and the waveguide receiver antennas 132 and 142 may be covered by a respective sealing membrane 161, 162; 163, and 164, which is configured to exclusively allow a unidirectional passage of moisture out from the first and second signal transceivers 100 and 200 respectively.

Additionally, or alternatively, the first and second signal trans- ceivers 100 and 200 may include a respective drainage system configured to let out any moisture formed inside, for example due to variations in interior temperature, ambient temperature and/or air humidity.

According to another embodiment of the invention, the first sig- nal and second signal transceivers 100 and 200 are enclosed in a moist-protective substance.

Figure 4 shows a perspective view of the first signal transceiver 100 according to the second embodiment of the invention, and Figure 5 shows a side view of the first signal transceiver 100 seen from the short side where the antennas 131, 132, 141 and 142 are arranged, which short side is configured to face the second signal transceiver 200.

Figures 4 and 5 also show the projecting element 171, which is configured to be received by at least one matching recess in the second signal transceiver 200 when the first coupling head 610 is mechanically connected to the second coupling head, and a recess 172 configured to receive an element projecting from the 18 second signal transceiver 200. As mentioned above, besides steering the first and second signal transceivers into mechanical contact with one another, the projecting element 171 and the recess 172 may be used to transfer electric power between the first and second transceivers 100 and 200.

Figure 6 shows a perspective view of the central buffer coupler 600 according to one embodiment of the invention, and Figure 7 shows a perspective view of a first communication unit 700 ac- cording to one embodiment of the invention. Here, the central buffer coupler 600 includes the first communication unit 700, which, in turn, contains two instances of the first signal transcei- ver 100. Such redundancy of the first signal transceiver 100, as well as of the second signal transceiver 200, is beneficial from a reliability point-of-view. Namely, should one of the signal trans- ceivers in one of the pairs thereof malfunction, the other pair may take over the responsibility for the communication between the first and second vehicle members.

The second signal transceiver 200 (not shown) is presumed to be comprised in a second communication unit (not shown). The first communication unit 700 has a first front side arranged to face a second front side presumed to be comprised in the se- cond communication unit, such that the first and second front sides meet when the coupling element 611 is mechanically con- nected to the counter-coupling element as described above.

According to one embodiment of the invention, the first front side of the first communication unit 700 contains first and se- cond electrical couplers 710 and 720 configured to connect gal- vanically with a corresponding pair of electrical couplers of the second front side of the second communication unit and thereby enable transfer of electric power between the first and second vehicle members when the coupling element 611 is mechanically connected to the counter-coupling element. ln Figure 8, we see an embodiment of the invention, where the 19 first communication unit 700 is provided with a cover 810, which is configured to be selectively arranged in a first or a second po- sition.

When the cover 810 is arranged in the first position, the at least one first waveguide transmitter antenna 131 and 141 and the at least one first waveguide receiver antenna 132 and 142 are physically screened-off by the cover 810.

When the cover 810 is arranged in the second position, the at least one first waveguide transmitter antenna 131 and 141 and the at least one first waveguide receiver antenna 132 and 142 are exposed for potential exchange of signals with the at least one second waveguide receiver antenna 232 and 242 and the second at least one transmitter antenna 231 and 241 respec- tively of the second signal transceiver 200.

Moreover, to verify in which of the first and second positions the cover 810 is arranged the first signal transceiver 100 is further configured to effect the following procedure. Primarily, cause the first microwave transmitter 111 and/or 112 to emit a probe signal; and secondarily, check a reception property of the probe signal via the at least one first microwave receiver 121 and/or 122. This may involve scanning a signal spectrum in which the probe signal was emitted to see if a strong reflection of the probe signal is received, which strong reflection is indicative of the cover 810 being arranged in the first position. Based on the reception property of the probe signal, the first signal transcei- ver 100 is configured to determine whether the cover 810 is arranged in the first or second position. For example, if no reflection of the probe signal above a threshold level is received, the first signal transceiver 100 may determine that the cover 810 is arranged in the second position.

Referring to the flow diagram of Figure 9, we will describe a computer-implemented method for effecting the above proce- dure in relation to the cover 810. ln a first step 910, at least one first microwave transmitter is controlled to emit a probe signal. The at least one first micro- wave transmitter is comprised in a first signal transceiver of a first coupling head mounted on a first vehicle member of a multi- member vehicle. ln a following or parallel step 920, at least one first microwave receiver is activated to check for any reflections of the probe signal. The at least one first microwave receiver is also compri- sed in the first signal transceiver.

Thereafter, a step 930 checks if a reflection of the probe signal was received at a signal power above a threshold level. lf so, a step 940 follows; and otherwise, the procedure continues to a step 950. ln step 940, the cover 810 is determined to be closed. Therefo- re, the at least one first microwave transmitter and receiver are inhibited, i.e. shut off from communicative operation. ln step 950, the cover 810 is determined to be open. Therefore, the at least one first microwave transmitter and receiver are enabled to operate in a communication mode.

Subsequently, the procedure ends.

The process steps described with reference to Figure 9 may be controlled by means of a programmed processor. Moreover, al- though the embodiments of the invention described above with reference to the drawings comprise processor and processes performed in at least one processor, the invention thus also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other form suitable for use in the imple- mentation of the process according to the invention. The pro- gram may either be a part of an operating system, or be a sepa- 21 rate application. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a Flash memory, a ROM (Read Only Memory), for example a DVD (Digital Video/Versatile Disk), a CD (Compact Disc) or a semiconductor ROM, an EPROM (Erasable Programmable Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), or a magnetic recording medium, for example a floppy disc or hard disc. Further, the carrier may be a transmissible carrier such as an electrical or optical signal which may be conveyed via elect- rical or optical cable or by radio or by other means. When the program is embodied in a signal, which may be conveyed, directly by a cable or other device or means, the carrier may be constituted by such cable or device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted for performing, or for use in the performance of, the relevant processes.

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed in- vention, from a study of the drawings, the disclosure, and the appended claims.

The term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, integers, steps or components. The term does not preclude the presence or addition of one or more additional elements, features, inte- gers, steps or components or groups thereof. The indefinite ar- ticle "a" or "an" does not exclude a plurality. ln the claims, the word "or" is not to be interpreted as an exclusive or (sometimes referred to as "XOR"). On the contrary, expressions such as "A or B" covers all the cases "A and not B", "B and not A" and "A and B", unless otherwise indicated. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope. lt is also to be noted that features from the various embodiments described herein may freely be combined, unless it is explicitly stated that such a combination would be unsuitable.

The invention is not restricted to the described embodiments in the figures, but may be varied freely within the scope of the claims.

Claims

1. A central coupling (600) for a four-wheeled vehicle, which central coupling (600) comprises: a first coupling head (610) adapted to be mounted on a first vehicle part of said four-wheeled vehicle, which first coupling - head (610) comprises at least a first signal transceiver (100) and a coupling element (611) configured to be mechanically connected to a counter-coupling element of a second coupling head mounted on a second vehicle part of said fourth vehicle, which second coupling head is assumed to comprise at least a second signal transceiver (200) arranged so that the at least one first and second signal transceivers (100; 200) are positioned facing each other in a physically matching manner when the coupling element (611) is mechanically connected to the counter-coupling element, characterized by that the at least one first signal transceiver (100) comprises at least one microwave transmitter (111, 112) and at least one microwave receiver (121, 122), which, when the coupling element (611) is mechanically connected to the counter-coupling element, are arranged so that, in at least one first interface module pair (151, 251; 152, 252): at least one first waveguide transmitter antenna (131, 141) of the first microwave transmitter (111, 112) of the at least one first microwave transceiver (100) physically matches at least one second waveguide receiver antenna (232, 242) which is assumed to be communicatively connected to at least a second microwave receiver (221, 222) of the at least one second signal transceiver (200), and at least one first waveguide receiver antenna (132, 142) of at least one first microwave receiver (121, 122) of the at least one first signal transceiver (100 ) physically matches at least one second waveguide transmitter antenna (231, 142) which is assumed to be communicatively connected to at least one second microwave transmitter (211, 212) of the at least one second signal transceiver (200), wherein the at least one first signal transceiver (100) includes is included in a first communication unit (700), where the at least one (5) second signal transceiver (200) is assumed to be part of a second communication unit, where the first communication unit (700) comprises a first front side arranged to be directed towards a second front side which is assumed to be part of the second communication unit, and at least one of the first and second front faces includes at least one projecting element (171) configured to be received by at least one matching recess in an opposite side of the at least one first and second front faces when the first coupling head ( 610) is mechanically connected to the second coupling head, and wherein the first communication unit (700) comprises a housing (810) configured to be selectively arranged in: a first position in which the at least one first waveguide transmitter antenna (13 , 141) and the at least one first waveguide receiver antenna (132, 142) are physically shielded by the housing (810), or a second position in which the at least one first waveguide transmitter antenna (13, 141) and the at least one first waveguide receiver the guarantor antenna (132, 142) is exposed to potential exchange of signals with the at least one second waveguide receiver antenna (232, 242) and the second at least one waveguide transmitter antenna (231, 241), respectively, and the first signal transceiver (100) is further configured to: cause the at least one first microwave transmitter (111, 112) emits a probe signal, check a reception characteristic of the probe signal via the at least one first microwave receiver (121, 122), and on the basis thereof determine whether the housing (810) is arranged in the first or second position.

2. The central coupler (600) according to claim 1, wherein each of said at least one interface module pair (151, 251; 152, 252) comprises at least one shielding wall member 151a, 151b, 151c; 152a, 152b, 152c) configured to prevent leakage of electromagnetic radiation from said at least one first and second signal transceiver (100, 200) during operation thereof.

3. The central coupling (600) according to claim 1, wherein each of the first and second front sides further comprises at least one respective z(5) electrical coupling (710, 720) configured to transmit electrical power between said first and second vehicle parts.

4. The central switch (600) according to one of the preceding claims, wherein the at least one first signal breather (100) comprises a first modem (110) configured to transform incoming packet data messages from the first vehicle part into outgoing microwave signals (l\/IW1, l\ /lW3) for transmission through the at least one first microwave transmitter (111, 112), and transform microwave signals (l\/lW2, l\/IW4) received by the at least one first microwave receiver (121, 122) into outgoing packet data messages to the first vehicle part.

5. The central switch (600) according to claim 4, wherein the first modem (110) is configured to communicate the packet data messages in an Ethernet format via at least one data bus (B11, B12, B1n, B21, B22, B2n; B11, B12, B1m, B21, B22, B2m) on at least one of at least one coaxial cable, at least one twisted-pair cable and at least one optical fiber.

6. The central switch (600) according to either claim 4 or 5, wherein the first modem (110) is configured to communicate the packet data messages while fulfilling traffic prioritization and resource reservation control mechanisms according to a quality of service standard.

7. The central switch (600) according to one of claims 4 to 6, wherein the first modem (110) is configured to be communicatively connected to one or more full-duplex microwave transmitter modules (181, 182) each of which includes a pair of the at least one first the microwave transmitter (111, 112) and the at least one first microwave receiver (121, 122).

8. The central switch (600) according to claim 7, wherein each of said one or more full-duplex microwave transmitter modules (181, 182) is configured to handle bidirectional data traffic at a certain bit rate. 9. The central buffer coupler (600) according to any one of the preceding claims, wherein: 3l5) each of the at least one first waveguide transmitter antenna (131, 141) comprises a respective horn antenna, and each of the at at least one first waveguide receiver antenna (132, 142) comprises a respective horn antenna.

9. The central coupler (600) according to one of the preceding claims, wherein: each of the at least one first waveguide transmitter antenna (131, 141) comprises a respective horn antenna, and each of the at least one first waveguide receiver antenna (132, 142) includes a respective horn antenna.

10. The central coupler (600) according to one of the preceding claims, wherein each of the at least one waveguide transmitter antenna (131, 141) and each of the at least one first waveguide receiver antenna (132, 142) comprises a sealing membrane (161, 162; 163 , 164) configured to allow only unidirectional passage of moisture out of the first and second signal transceivers (100, 200), respectively.

11. The central coupler (600) according to one of the preceding claims, wherein the first signal transceiver (100) is enclosed in a moisture-protective substance

12. A signal transceiver (100) included in the central coupler (600) according to any of the preceding claims.

13. A vehicle part configured to form part of a multi-part vehicle, which vehicle part comprises the central coupling (600) according to one of claims 1 to

14. A computer-implemented method comprising the steps: controlling at least one microwave transmitter (111, 112) to emit a probe signal, which at least one microwave transmitter (111, 112) is included in a first signal transceiver (100) of a first coupling head (610) mounted on a first vehicle part of a multi-part vehicle; controlling at least one microwave receiver (121, 122) to transmit a probe signal, which at least one microwave receiver (121, 122) is included in the first signal transmitter (100); and on the basis 4(5) thereof, determining whether a housing (810) is arranged in: a first position in which the at least one first guidance transmitter antenna (13, 141) and the at least one first guidance receiver antenna (132, 142) are physically shielded by the housing (810), or a second position in which the at least one first directional transmitter antenna (13, 141) and the at least one first directional receiver antenna (132, 142) are exposed to potential exchange of signals with the at least one second guide receiver antenna (232, 242) and the second at least one guide transmitter antenna (231, 241), respectively; and only if the housing (810) is determined to be in the second position enable the at least one first microwave transmitter (111, 112) and the at least one first microwave receiver (121, 122) to operate in a communication mode. p(5)