BUS SYSTEM, SUBSCRIBER STATION THEREFOR, AND METHOD FOR CONFIGURING A STATIC BUS SYSTEM FOR A DYNAMIC COMMUNICATION

Abstract

A bus system, a subscriber station, and a method for configuring a static bus system for a dynamic communication are provided. The bus system has at least two subscriber stations, a communications link for connecting the subscriber stations to each other, and at least one device for the dynamic communication between the subscriber stations of the bus system; the subscriber stations and the communications link are developed for the static communication, which is directed to messages to be transmitted on the bus system that are known when the bus system is made available and are configured according to specified transmitters and receivers, and the dynamic communication is directed to messages to be transmitted on the bus system that have become known only after the subscriber stations and the communications link have been made available and are configured according to specified transmitters and receivers.

Claims

1-10. (canceled)

11. A bus system, comprising: at least two subscriber stations; a communications link for connecting the at least two subscriber stations to one another; and at least one device for dynamic communication between the at least two subscriber stations of the bus system; wherein the at least two subscriber stations and the communications link are developed for a static communication, the static communication being directed to messages to be transmitted on the bus system that are known when the bus system is made available and are configured according to specified transmitters and receivers, and wherein the dynamic communication is directed to messages to be transmitted on the bus system, which are known only since the at least two subscriber stations and the communications link have been made available and are configured according to specified transmitters and receivers.

12. The bus system as recited in claim 11, wherein a transmission of the messages on the bus system is carried out in a twofold priority-oriented manner, in which both a priority of the message and a priority of an allocated communications resource are taken into account.

13. The bus system as recited in claim 11, wherein the at least two subscriber stations for the static communication each have a communications hardware and a communications software for a transmission of the messages via the communications link, the communications hardware, the communications software, and the communications link being devices for the static communication.

14. The bus system as recited in claim 13, wherein the devices for the static communication include the at least one device for the dynamic communication.

15. The bus system as recited in claim 11, wherein making the bus system available refers to the delivery of a product that includes at least one of the bus system, the bus system is the bus system of a vehicle, and the bus system is a serial bus system.

16. The bus system as recited in claim 11, wherein messages of the dynamic communication include at least one of: (i) at least a portion of a payload data of the dynamic communication as an identifier in the payload data of the messages, and (ii) in a predefined number of low-priority bits of the identifier, which is provided for the message of the dynamic communication.

17. The bus system as recited in claim 11, wherein the bus system is one of a CAN or a CAN FD bus system, and the at least one device for the dynamic communication is developed to use at least one previously reserved identifier of the one of the CAN or the CAN FD bus system, each one of the previously reserved identifiers is allocated to maximally one subscriber station for the transmission of a message, and all subscriber stations are developed to receive the previously reserved identifiers.

18. The bus system as recited in claim 11, wherein the bus system is a FlexRay bus system, and the at least one device for the dynamic communication is developed to use at least one previously reserved time window of the FlexRay bus system, and each one of the previously reserved time windows is allocated to maximally one subscriber station for the transmission of a message, and all subscriber stations are developed to receive content of the previously reserved time windows.

19. A subscriber station for a bus system, comprising: a communications-control unit for generating or reading a message for or from a further subscriber station of the bus system; a transceiver device for at least one of: (i) transmitting a message generated by the communications-control unit to a further subscriber station of the bus system, and (ii) receiving a message from a further subscriber station of the bus system via a communications link of the bus system; and a device for dynamic communication between the subscriber station and the further subscriber station; wherein the communications-control unit and the transceiver device are developed for a static communication, which is directed to messages to be transmitted on the bus system that are known when the subscriber station is made available, and wherein the dynamic communication is directed to messages to be transmitted on the bus system that are not known when the subscriber station is made available.

20. A method for configuring a static bus system having at least two subscriber stations which are connected to a communications link of the bus system for dynamic communication, the at least two subscriber stations and the communications link being developed for a static communication, which is directed to messages to be transmitted on the bus system that are known when the bus system is made available and are configured according to specified transmitters and receivers, and the dynamic communication is directed to messages to be transmitted on the bus system that are known only after the at least two subscriber stations and the communications link have been made available and are configured according to specified transmitters and receivers, the method comprising: providing at least one device for the bus system, which is developed for the dynamic communication between the at least two subscriber stations of the bus system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Below, the present invention is described in greater detail on the basis of exemplary embodiments with reference to the figures.

[0024] FIG. 1 shows a simplified block diagram of a bus system according to a first exemplary embodiment.

[0025] FIG. 2 shows a representation of a structure of a frame in the bus system according to the first exemplary embodiment.

[0026] FIG. 3-6 show the format of CAN FD frames with the placement of the first four identifier bits (ID28-ID25) to be checked, and check bit RRS, with reference to a second exemplary embodiment in each case.

[0027] Identical or functionally equivalent elements have been provided with the same reference numerals in the figures, unless otherwise noted.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0028] In a first exemplary embodiment, FIG. 1 shows a bus system 1, which may be a CAN FD bus system, for instance. Bus system 1 may be used in a vehicle, in particular a motor vehicle, an airplane, etc., or in the industrial field such as in control systems etc., or in a hospital, and others.

[0029] In FIG. 1, bus system 1 has a communications link 5, which connects a multitude of subscriber stations 10, 20, 30. Frames or messages 50, 60 are able to be transmitted between individual subscriber stations 10, 20, 30 via communications link 5. For example, communications link 5 may be developed as a wire-conducted bus line or as a wireless connection. Subscriber stations 10, 20, 30 could be control units, sensors, display devices, etc. of a motor vehicle, for instance. Messages 50 are what are called static messages, and messages 60 are so-called dynamic messages.

[0030] Static messages 50 reflect the information that is known at the time when bus system 1 is brought into the market, e.g., in a new vehicle, building, etc. Such knowledge relates to the transmitters of the information and the representation of the information on bus system 1 and mostly to the receivers of the information. The data that describe the information to be conveyed or transmitted with the aid of messages 50 are also referred to as configuration. The configuration is part of the static communications software of bus system 1, in which it is precisely specified which messages 50 are generated by which particular transmitters. In contrast thereto, dynamic messages 60 reflect all the information that becomes known after bus system 1 has been brought into the market, such as in a new vehicle, building, etc.

[0031] Quite generally, the static communication on bus system 1 is provided on the basis of a configuration of bus system 1 that was set up prior to the first operation of bus system 1, and the dynamic communication is provided on the basis of a configuration of bus system 1 that was set up after the first use of bus system 1.

[0032] As shown in FIG. 1, subscriber station 10 has a communications-control unit 11, a device 12 for the dynamic communication, and a transceiver unit 13. In contrast, subscriber station 20 has a communications-control unit 21 which includes a device 22 for the dynamic communication, and a transceiver device 23. Subscriber station 30 has a communications-control unit 31 and a transceiver device 33, which includes a device 32 for the dynamic communication. Transceiver devices 13, 23, 33 of subscriber stations 10, 20, 30 are directly connected to communications link 5 in each case, even if this is not shown in FIG. 1.

[0033] Communications-control units 11, 21, 31 control a communication of respective subscriber station 10, 20, 30 by way of communications link 5 with a further subscriber station of the subscriber stations 10, 20, 30 connected to communications link 5. Communications-control units 11, 21, 31 may be developed like a conventional CAN or CAN FD controller with regard to the static communication. Communications-control units 11, 21, 31 may also be developed as a part of a microcontroller in each case, which is also included by respective subscriber station 10, 20, 30.

[0034] Transceiver devices 13, 23, 33 transmit or receive messages 50, 60 generated or to be read by the respectively allocated communications-control unit 11, 21, 31. Transceiver devices 13, 23, 33 may be developed in the manner of a conventional CAN or CAN FD transceiver in each case.

[0035] Devices 12, 22, 33 for the dynamic communication are also able to be developed in the form of software modules, which form part of the software running on associated subscriber station 10, 20, 30 for the dynamic communication on bus system 1.

[0036] FIG. 2 shows the structure of a static message 50. Static message 50 is structured like a conventional CAN or CAN FD message. Static message 50 has a data header 51, payload data 52, and a trailer 53. In addition to control bits 511, data header 51 includes an identifier 512, which allows message 50 to be clearly allocated to subscriber station 10, 20, 30 that has generated message 50. Trailer 53 identifies the end of message 50.

[0037] Payload data 2 include the information that is to be transmitted by one of subscriber stations 10, 20, 30 to another subscriber station 10, 20, 30 by way of communications link 5. Payload data 52 have content or information that is known when bus system 1 is made available, as described in the previous text. For example, payload data 52 may be measured values that a sensor as a subscriber station 30 transmits to a brake-control unit as subscriber station 20. In this instance, it is already known when bus system 1 is made available that the sensor as subscriber station 30 will transmit such measured values to the brake-control unit as subscriber station 20 during a standard operation.

[0038] In addition, communications-control units 11, 21, 31 and transceiver devices 13, 23, 33 are developed in such a way that they are all able to exchange messages 50 that are generated for allocated subscriber station 10, 20, 30 by other subscriber stations 10, 20, 30 and which are generated for another subscriber station 10, 20, 30.

[0039] FIG. 3 illustrates the structure of a dynamic message 60. Dynamic message 60 is basically structured like a conventional CAN or CAN FD message. As a result, dynamic message 60 also has a data header 61, payload data 62, and a trailer 63. In addition to control bits 611, data header 61 includes an identifier 612, which allows for a clear allocation of message 60 to subscriber station 10, 20, 30 that has generated message 60. Trailer 63 identifies the end of dynamic message 60.

[0040] Payload data 62 include as further identifiers or information identifier 621 the information that is to be transmitted by one of subscriber stations 10, 20, 30 to a further subscriber station 10, 20, 30 by way of communications link 5. Payload data 62 in dynamic message 60 have content or information that is not known when bus system 1 is made available. For example, payload data 62 could be measured values, which a sensor, added to the bus system at a later point in time, as subscriber station 30 transmits to a display device as subscriber station 10 and/or to a brake-control unit as subscriber station 20. In this instance, it is therefore not yet known when bus system 1 is made available that the sensor as subscriber station 30 will transmit such measured values to the display device as subscriber station 10 and/or to a brake-control unit as subscriber station 20 during a normal operation.

[0041] Each reserved identifier 612 is allocated to maximally one subscriber station of subscriber stations 10, 20, 30, which is able to use this reserved identifier for a transmission.

[0042] Reserved identifiers 612 for the dynamic communication are able to be received by all transceiver devices 13, 23, 33 or all subscriber stations 10, 20, 30 and may be used by devices 12, 22, 32 for the dynamic communication.

[0043] The content of the dynamic communication, i.e. the information or dynamic payload data 62 to be transmitted between at least two of subscriber stations 10, 20, 30, is thus identified by information identifiers 621, which are part of payload data 62 of a dynamic message 60. The identification of the dynamic communications content, i.e. payload data 62, and the identification of the communications resources statically made available, via identifier 612, are thus independent of each other.

[0044] A service-oriented protocol such as SOME/IP, or a derivation thereof may be used for the identification of the information in payload data 62 that is identified via identifier 621. The service-oriented protocol is able to be executed by respective device 12, 22, 32 for the dynamic communication upon receipt of a message 60.

[0045] In this particular exemplary embodiment, devices 12, 22, 32 for the dynamic communication are thus designed to use identifiers 612, 621 as communications resources that are reserved for the dynamic communication. At the time of the reservation, it is not known for which information these communications resources will be used at a later date. Devices 12, 22, 32 for the dynamic communication may be developed as an application program (app), which is later loaded onto the corresponding subscriber station 10, 20, 30 in order to generate and/or read messages 60.

[0046] As illustrated in FIG. 4, it is also advantageous if device 12 for the dynamic communication includes a service dispatcher 121, which groups messages 50, 60 to be transmitted according to the priority of messages 60 to be transmitted. Devices 22, 32 for the dynamic communication are structured in the same way as device 12 for the dynamic communication.

[0047] For example, three groups exist, which have different priorities with regard to the information to be transmitted. In FIG. 4, a first message group 71 has the highest priority, a second message group 72 has an average priority, and a third message group 73 has the lowest priority. Any number of such priority-based groups 71, 72, 73 may exist.

[0048] Alternatively or additionally, service dispatcher 121 may consider static communications resources 131, 132, 133 allocated for the dynamic communication also according to their priority. To do so, for example, three communications resources 131, 132, 133 may likewise be available, in which case communications resource 131 has the highest priority, communications resource 132 has the average priority, and communications resource 133 has the lowest priority. When a communications resource 131, 132, 133 is allocated a message 60 to be transmitted, communications resource 131, 132, 133 for the transmission of message 60 is occupied until this message 60 has been successfully transmitted onto communications link 5. Communications resource 131, 132, 133 will then be available again.

[0049] As a result, service dispatcher 121 may operate in a priority-based manner either in a single or twofold manner. Accordingly, service dispatcher 121 is able to transmit messages 60 according to their allocation to the first through the third message groups 71, 72, 73. Service dispatcher 121 then transmits messages 60 having a low priority only when no message 60 having a higher priority is ready to be transmitted. Alternatively or additionally, service dispatcher 121 may always use communications resource 131, 132, 133 that is available and has the highest priority. If service dispatcher 121 is meant to operate only in a simple priority-oriented manner, then service dispatcher 121 may be appropriately developed only for the desired priority orientation.

[0050] FIG. 5 shows a bus system 2 according to a second exemplary embodiment, in which messages 65 are transmitted during the dynamic communication. In all other respects, bus system 2 in this particular exemplary embodiment is structured in the same manner as described with reference to the preceding exemplary embodiment. As a result, only the differences of bus system 2 in comparison with bus system 1 are described in the following text.

[0051] FIG. 6 shows a dynamic message 65, which is transmitted on a bus system 2 according to the second exemplary embodiment. Message 65 is structured similarly to message 60 from FIG. 3. As a result, dynamic message 65 also includes data header 61, payload data 62, and a trailer 63. In addition to control bits 651, data header 61 has an identifier 652, which makes it possible to clearly allocate message 65 to subscriber station 10, 20, 30 that has generated message 65. Trailer 63 identifies the end of dynamic message 65.

[0052] However, in contrast to message 60, identifier 652 in message 65 is subdivided into two parts. One part is used for the identification, and one part, i.e. in the form of information identifier 621, is used for transporting payload data 62.

[0053] In the development of a bus system 2 as a CAN bus, for example, the 11-bit identifier may be used for the static communication, i.e. for the transmission of messages 50. In contrast, the 29-bit identifiers are used for the dynamic communication, i.e. for the transmission of messages 65. This may be done in such a way that the last 18 bits of the 29-bit identifier are utilized as part of information identifier 621, and thus for the transport of payload data 62. The identification and allocation of the statically allocated communications resources then takes place via the first 11 bits of identifier 652.

[0054] Such a development of dynamic message 65 and the associated development of subscriber stations 10, 20, 30 and communications link 5 for generating, transmitting and receiving dynamic message 70 is advantageous in particular on bus systems 2 that has a low number of payload data. Since identifier 652 fully or partly co-uses the static communications resources for the identification of the dynamic communications content or a portion of actual payload data 62, payload data 62 are able to be used for other purposes.

[0055] FIG. 7 shows a bus system 3 according to a third exemplary embodiment. Bus system 3 operates on the basis of the FlexRay standard, which is specified in the ISO standard ISO 17458-1 through 17458-5. A number of slots, or time slots 551 through 55N, is therefore provided for static messages 55.

[0056] In addition, instead of identifiers 612, 621, 652 (FIG. 3, FIG. 5), a predefined number of slots or time slots 661 through 66N is reserved for the dynamic communication in bus system 3, for dynamic messages 66. Each one of these reserved time slots 661 through 66N is then allocated to maximally one subscriber station 10, 20, 30, which may use it for transmission purposes. The content of time slots 661 through 66N is able to be received by all subscriber stations 100, 200, 300.

[0057] As illustrated in FIG. 7, subscriber station 100 has a communications-control unit 110, a device 120 for the dynamic communication, and a transceiver device 130. In contrast, subscriber station 200 has a communications-control unit 210, which includes a device 220 for the dynamic communication, and a transceiver device 230. Subscriber station 300 has a communications-control unit 310 and a transceiver device 330, which includes a device 320 for the dynamic communication. Transceiver devices 130, 230, 330 of subscriber stations 100, 200, 300 are each directly connected to communications link 5, even if this is not shown in FIG. 7.

[0058] With the exception of their development for the FlexRay standard, communications-control units 110, 120, 130 have the same function as communications-control units 11, 12, 13 in the preceding exemplary embodiments. Transceiver devices 110, 120, 130 have the same function as transceiver devices 11, 12, 13 in the preceding exemplary embodiments with the exception of their development for the FlexRay standard. In the same way, devices 120, 220, 320 for the dynamic communication have the same function as devices 12, 22, 32 for the dynamic communication in the preceding exemplary embodiments, except for their development for the FlexRay standard.

[0059] In all other respects, bus system 3 has the same structure as described in connection with the preceding exemplary embodiments.

[0060] All previously described specific embodiments of bus system 1, 2, 3, of subscriber stations 10, 20, 30, 100, 200, 300, and of the method executed on bus system 1, 2, 3 may be used individually or in all kinds of combinations. In particular, all features of the previously described exemplary embodiments and/or their modifications may be combined or omitted as desired. In addition, in particular the following modifications are possible.

[0061] The previously described bus systems 1, 2 according to the first and the second exemplary embodiment are described with the aid of a bus system that is based on the CAN or the CAN FD protocol. However, bus system 1 according to the exemplary embodiments may also involve some other type of communications network. It is advantageous, but not a mandatory requirement, that an exclusive, collision-free access of a subscriber station 10, 20, 30 to a shared channel is ensured on bus system 1, 2, at least for certain time periods.

[0062] The number and placement of subscriber stations 10 through 30 in bus systems 1, 2 of the first and second exemplary embodiments are freely selectable. In particular, it is also possible that only subscriber stations 10 or 20 or 30 are available on bus system 1 or 2. Any combinations of subscriber stations 10 through 30 in bus systems 1, 2 are possible. The same applies to subscriber stations 100 through 300 in bus system 3.

[0063] Within the meaning of the present invention, service dispatcher 121 may also carry out the allocation of messages 50, 60 to the communications resource according to some logic other than the one described in connection with FIG. 4. Important in this context is only that service dispatcher 121 transmits messages 50, 60 on provided communications resources 131, 132, 133.

[0064] Instead of at least one identifier 612, 621 of a message 50, 60, 70 transmitted via the bus, or a corresponding use of a cycle counter, as described previously with reference to the exemplary embodiments, port addresses may also be provided in another bus system in order to enable a dynamic communication on an initially static bus system.