Lin Bus via Backbone Bus Tunneling

Abstract

Embodiments relate to a system for transmitting data in a motor vehicle. A central electronic control unit comprises at least one LIN master, and at least one local controller, which is coupled to the central controller by means of a first data connection. The local controller is additionally coupled to a LIN bus, which is paired with the LIN master and to which at least one LIN slave is connected. The data transmission speed of the first data connection between the central controller and the local controller is faster than the data transmission speed of the LIN bus. Methods for actuating a LIN slave connected to a LIN bus and to a motor vehicle are also provided.

Claims

1-15. (canceled)

16. A system for transmitting data in a motor vehicle, comprising: a central electronic control unit comprising a LIN master; and at local electronic control unit coupled to the central electronic control unit by a first data connection, wherein the local electronic control unit is also coupled to a LIN bus assigned to the LIN master and to a LIN slave, and a data transmission speed of the first data connection between the central electronic control unit and the local electronic control unit is higher than a data transmission speed of the LIN bus.

17. The system according to claim 16, wherein the LIN master and/or the LIN slave is/are formed in a hardware-supported manner on microcontrollers.

18. The system according to claim 16, wherein the system is configured, within a duration of a predefined nominal time slot for the data transmission of a frame via the LIN bus, to transmit both the frame via the LIN bus and header information and response information corresponding to the frame via the first data connection.

19. The system according to claim 16, wherein the system is configured, within a tolerance time of a LIN frame that is provided according to a LIN standard, to interchange response information and header information via the first data connection between the LIN master and the local electronic control unit.

20. The system according to claim 16, further comprising: a second local electronic control unit which is coupled to the central electronic control unit via the first data connection.

21. The system according to claim 16, wherein the central electronic control unit comprises: a plurality of LIN masters, and the local electronic control unit is coupled to a plurality of LIN buses.

22. The system according to claim 16, wherein the data transmission speed of the first data connection is higher than the data transmission speed of the LIN bus at least by a factor of 10.

23. The system according to claim 16, wherein the first data connection is designed according to an Ethernet standard, a CAN standard, a FlexRay standard, a radio-based transmission standard, or a home network standard.

24. A method for controlling a LIN slave connected to a LIN bus, comprising: transmitting header information from a LIN master of a central electronic control unit to a local electronic control unit via a first data connection between the central electronic control unit and the local electronic control unit, wherein the first data connection has a higher data transmission speed than the LIN bus; receiving the header information at the local electronic control unit; and transmitting the header information to the LIN slave via the LIN bus connected to the local electronic control unit.

25. The method according to claim 24, also comprising: receiving response information corresponding to the header information from the LIN slave at the local electronic control unit; and transmitting the response information from the local electronic control unit to the LIN master of the central electronic control unit via the first data connection, wherein a predetermined time slot is used to transmit the header information and the response information via the LIN bus, wherein the response information and/or further header information is transmitted via the first data connection within a time window reserved in the time slot.

26. The method according to claim 25, wherein the reserved time window has a duration of at least 0.5 ms.

27. The method according to claim 24, further comprising: transmitting second header information from a second LIN master of the central electronic control unit via the first data connection, wherein the second header information is transmitted in a delayed manner with a time offset (t.sub.off) which is selected based on a data transmission speed of the first data connection.

28. The method according to claim 24, wherein during transmission via the first data connection, the header information is embedded in a data packet of a standard of the first data connection.

29. The method according to claim 24, wherein an Ethernet connection is used as the first data connection, and, during transmission via the Ethernet connection, the header information and/or the response information is embedded in a 64-byte Ethernet frame.

30. A motor vehicle having a system according to claim 16, wherein a transmission cable of the first data connection and/or of the LIN bus is routed through a vehicle pillar of the motor vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Examples are explained in more detail below with reference to the accompanying figures, in which:

[0039] FIG. 1 shows a schematic example of a system having a central electronic control unit and a local electronic control unit;

[0040] FIG. 2 shows a schematic example of a system having two local electronic control units;

[0041] FIG. 3 shows an example of a system having LIN buses;

[0042] FIG. 4 shows a flowchart of a method for controlling a LIN slave;

[0043] FIG. 5 shows an example of transmission of header information and response information via a first data connection and a LIN bus; and

[0044] FIG. 6 shows an example of transmission of a plurality of frames via the first data connection to a plurality of LIN buses using a time offset.

DETAILED DESCRIPTION

[0045] Various examples are now described in more detail with reference to the accompanying drawings which illustrate some examples. In the figures, the thickness dimensions of lines, layers and/or regions may be illustrated in an exaggerated form for the sake of clarity. In the following description of the attached figures which show only some examples, identical reference signs may denote identical or comparable components.

[0046] An element which is referred to as being “connected” or “coupled” to another element may be directly connected or coupled to the other element or there may be elements in between. As long as there is no definition to the contrary, all terms used herein (including technical and scientific terms) have the same meaning as that attributed to them by a person of average skill in the art in the field to which the examples belong.

[0047] FIG. 1 shows a schematic example of a system 10 having a central electronic control unit 11 and a local electronic control unit 12. The central electronic control unit 11 and the local electronic control unit 12 are connected by means of a first data connection 13. At least one bus, in particular a LIN bus 14 having at least one slave, in particular a LIN slave 15a, is also coupled to the local electronic control unit 12. The LIN bus 14 and the LIN slave 15a are assigned to a master, in particular a LIN master 11a, which is arranged in the central electronic control unit 11. The system 10 may be used in motor vehicles, for example.

[0048] Providing the first data connection 13 having a higher data transmission speed than the LIN bus may make it possible, for example, to connect further LIN buses to the local electronic control unit 12 without their transmission cables each having to be individually routed to the central electronic control unit 11 with the associated LIN masters. As a result, the system 10 may make it possible to reduce a cable requirement when using a plurality of LIN buses.

[0049] For example, the first data connection 13 may be used as a central data connection (for example central bus or backbone bus) in order to tunnel header information and response information from the respective LIN bus to the associated LIN masters in the central electronic control unit 11.

[0050] Alternatively, instead of the LIN bus, it is also possible to provide another bus system which has a lower data transmission speed than the first data connection 13.

[0051] Further details and aspects are mentioned in conjunction with the examples described above or below. The example shown in FIG. 1 may have one or more optional additional features which correspond to one or more aspects mentioned in conjunction with the proposed concept or with one or more examples described above or below (for example FIGS. 2-6).

[0052] FIG. 2 shows a schematic example of a system 10 having two local electronic control units 12, 12b. In this case, a plurality of LIN masters 11a, 11b, 11n are arranged in the central electronic control unit 11. Three LIN masters (inter alia LIN masters 11a, 11b) can be used to control LIN buses 14, 14b, 14c connected to the first local electronic control unit 12. Further LIN masters (inter alia LIN master 11n) can be used to control LIN buses 14d, 14n connected to the second local electronic control unit 12b.

[0053] For example, the two local electronic control units 12, 12b may be arranged at different positions which are each closer to LIN slaves assigned to the LIN buses. This makes it possible to further reduce overall a required cable length for the LIN buses 14, 14b, 14c, 14d, 14n since the two local electronic control units 12, 12b can share the first data connection 13. For example, further local electronic control units can be coupled to the first data connection 13 in a similar manner.

[0054] Further details and aspects are mentioned in conjunction with the examples described above or below. The example shown in FIG. 2 may have one or more optional additional features which correspond to one or more aspects mentioned in conjunction with the proposed concept or with one or more examples described above (for example FIG. 1) or below (for example FIGS. 3-6).

[0055] FIG. 3 shows an example of a conventional system having a plurality of LIN buses 140, 140b, 140n. The LIN buses 140, 140b, 140n are all directly connected to the electronic control unit 110 in which respective LIN masters 110a, 110b, 110n assigned to the buses are arranged. In contrast to the proposed system 10, this increases the need for transmission cables with each additional LIN bus since no shared transmission cable can be used for a plurality of LIN buses.

[0056] FIG. 4 shows a flowchart of a method 30 for controlling a LIN slave. The method 30 comprises transmitting 31 header information from a LIN master of a central electronic control unit to a local electronic control unit via a first data connection between the central electronic control unit and the local electronic control unit. In this case, use is made of the first data connection having a higher data transmission speed than the LIN bus. The method 30 also comprises receiving 32 the header information at the local electronic control unit, and transmitting 33 the header information to the LIN slave via the LIN bus connected to the local electronic control unit.

[0057] The method 30 may make it possible to transmit header information for a plurality of LIN buses via a shared data channel, the first data connection. This makes it possible to reduce a necessary cable requirement, for example.

[0058] Further details and aspects are mentioned in conjunction with the examples described above or below. The example shown in FIG. 4 may have one or more optional additional features which correspond to one or more aspects mentioned in conjunction with the proposed concept or with one or more examples described above (for example FIGS. 1-3) or below (for example FIGS. 5-6).

[0059] FIG. 5 shows an example of transmission of header information H and response information R via a first data connection 13 (for example a CAN bus; see upper half of FIG. 5) and a LIN bus 14. A time slot 80 is used to transmit a frame comprising a header (header information H) and a response or slave response (response information R) via the LIN bus 14 (see lower half of FIG. 5). The illustrated length of the time slot 80 is purely exemplary and, instead of the 10 ms illustrated, may also be 5 ms or have other durations.

[0060] As can be seen, a first part of the time slot 80 suffices to transmit the header information H and response information R via the LIN bus 14, with the result that a free time window 81 arises or can be used until the beginning of a next time slot. For example, the duration of the time window is approximately 33% of the duration of the time slot 80 (for example at most 40% and/or at least 20% of the duration of the time slot 80). The free time window 81 can be provided if the tolerance times defined in the LIN transmission standard are not needed to transmit the LIN frame. The free time window 81 can therefore also be referred to as a tolerance time 81.

[0061] The free time window 81 in which no information is transmitted via the LIN bus 14 can be used to transmit the response information R back to the LIN master in the central electronic control unit via the first data connection 13 (for example tunneling the response information R). Furthermore, further header information H.sub.n+1 for transmitting a header via the LIN bus 14 in the next time slot can be transmitted from the LIN master to the local electronic control unit via the first data connection 13. The header information R for the illustrated LIN frame of the time slot 80 was accordingly transmitted in a free time window of the previous time slot (see header information H on the first data connection 13 temporally before the beginning of the time slot 80). The period of time from the beginning of the transmission of the header information H via the first data connection 13 to the end of the reception of the associated response information R via the first data connection 13 may therefore be effected in a period of time which is shorter than the duration of the time slot 80.

[0062] Further details and aspects are mentioned in conjunction with the examples described above or below. The example shown in FIG. 5 may have one or more optional additional features which correspond to one or more aspects mentioned in conjunction with the proposed concept or with one or more examples described above (for example FIGS. 1-4) or below (for example FIG. 6).

[0063] FIG. 6 shows an example of transmission of a plurality of frames f.sub.1, f.sub.2, f.sub.3 via the first data connection 13 to a plurality of LIN buses 14, 14b, 14c using a time offset t.sub.off. The time offset t.sub.off may describe, for example, the period of time between the beginning of the first header information H and the beginning of the next header information H.sub.2. For example, the transmission of header information via the first data connection 13 may last for between 50 and 60 μs and the time offset t.sub.off may be 100 82 s. For example, the time offset t.sub.off may define a period of time between the end of the transmission of the header information H and the beginning of the transmission of the header information H.sub.2 and may be, for example, more than 10 μs and/or less than 50 μs.

[0064] The header information H, H.sub.2, H.sub.3 is successively transmitted by different LIN masters, via the first data connection 13, to the various LIN buses 14, 14b, 14c each assigned to the LIN masters. As can be seen, the slower data transmission of the frames f.sub.1, f.sub.2, f.sub.3 via the LIN buses 14, 14b, 14c requires more time than the data transmission of header information and response information via the first data connection 13. Therefore, after the first header information H has been transmitted by a first LIN master via the first data connection 13, further header information H.sub.2, H.sub.3, etc. can be transmitted by further LIN masters, for example as long as the frame f.sub.1 is transmitted via the LIN bus 14. For example, a maximum possible number of items of header information H, H.sub.2, H.sub.3, etc. which can be transmitted via the shared data connection 13 may depend on the data transmission speed and/or the length of the time offset t.sub.off and/or the duration of the frame f.sub.1. For example, the time offset t.sub.off can be selected in such a manner that response information can be transmitted via the first data connection 13 between the transmission of two successive items of header information in order to achieve, for example, permanently alternating transmission of header information and response information via the first data connection 13.

[0065] Synchronization of the LIN masters with the offset t.sub.off may enable, for example, collision-free scheduling on the backbone bus (for example first data connection 13). For example, the time slots of the LIN buses 14, 14b, 14c are each arranged in a manner offset by the time offset. The use of the synchronization or time offset may make it possible for the plurality of LIN masters to subsequently be able to transmit further headers of subsequent LIN frames for the assigned LIN buses 14, 14b, 14c via the first data connection 13 without producing collisions on the first data connection 13.

[0066] Further details and aspects are mentioned in conjunction with the examples described above or below. The example shown in FIG. 6 may have one or more optional additional features which correspond to one or more aspects mentioned in conjunction with the proposed concept or with one or more examples described above (for example FIGS. 1-5) or below.

[0067] Examples relate to a method for tunneling a LIN bus 14 via a backbone bus (for example the first data connection 13, for example a CAN bus or an Ethernet connection). In order to be able to automatically produce the cable harness in a more streamlined and cheaper and/or better manner, one or more backbone buses (for example, first data connection) are introduced, via which buses, for example LIN, CAN, FlexRay, and discrete signals can be tunneled.

[0068] In this case, tolerances present in the LIN specification can be used, in particular. These tolerances (for example free time window 81) are no longer needed on the LIN bus, for example, in the case of modern available microcontrollers (μCs) with hardware LIN logic (for example, hardware-supported). It is possible to carry out synchronization with time offset of the LIN masters of those LIN buses which are intended to be tunneled together. For example, a time buffer (for example the time window 81) is provided for tunneling LIN buses. If a plurality of LIN buses are tunneled on the same backbone bus, collisions can be avoided by means of proposed concepts. For example, a plurality of LIN buses can be routed from a central electronic control unit to a rear electronic control unit and/or roof electronic control unit.