ON-BOARD ELECTRICAL SYSTEM FOR A MOTOR VEHICLE

Description

[0001] The invention relates to an on-board electrical system for a vehicle, which is divided into individual zones. On-board electrical systems with a zonal structure can be found, for example, in DE 100 23 088 B4, DE 10 2016 212 065 A1 or EP 3 192 704 A1.

[0002] In vehicle electrical systems with a zonal structure, energy and signal distribution is typically implemented using three to four so-called zonal control units, primarily responsible for body and comfort functions. These zonal control units are located in corresponding areas within the vehicle, representing, for example, the four corners of the vehicle and typically separating the dry and wet areas. Each of these zonal control units is typically connected to a central control unit, which performs the overall control of the vehicle's functionalities. Such central control units are also known as HPCs (High Performance Controllers). The main objective of these zonal control units, namely to significantly simplify wiring harness structures, could not be achieved.The intended cost reduction was also not achieved, as very expensive and complex decentralized control units are required, and similar adjustments are necessary as with conventional, non-zonal wiring harnesses. To achieve the desired higher degree of modularization for simplified assembly, many so-called inline connectors are needed to separate subassemblies and thus partial wiring harnesses from a main wiring harness. This also leads to an undesired increase in costs.

[0003] EP 3 866 405 B1 describes a communication system for a motor vehicle in which the vehicle is divided into several zones that are independently designed.

[0004] US 2004 / 227402 A1 also describes an on-board network divided into zones, in which controllers are provided for the different zones.

[0005] DE 10 2021 202496 A1 shows a distribution system for an on-board network which has a zonal on-board network structure.

[0006] US 2014 / 368032 A1 describes a network infrastructure specifically for an electrical transmission network.

[0007] US 2005 / 066062 A1 describes a bus system of a network, in which one of the bus components forms a time master.

[0008] Based on this, the invention aims to provide an on-board electrical system that is flexible with regard to a wide variety of requirements.

[0009] The problem is solved according to the invention by an on-board electrical system for a motor vehicle, which in the installed state is part of the motor vehicle, wherein: The vehicle electrical system comprises numerous sub-zones. These sub-zones are sections of the electrical system defined by assembly groups during final vehicle assembly and their pre-assembly (e.g., front-end pre-assembly, rear-end pre-assembly, door pre-assemblies with one or more routing areas, cockpit assembly pre-assembly, seat pre-assembly, and potentially other vehicle-specific pre-assemblies). The assemblies themselves are pre-assembled components such as front bumpers, rear bumpers, door assemblies with one or more door modules, cockpit or instrument panel assemblies, rear assemblies, and seat assemblies. Each of these assemblies includes a (mechanical) vehicle module, a partial wiring harness, and electrical components connected via this harness. Each sub-zone contains multiple such electrical components.These components include, in particular, actuators (actuators, valves, heating elements, lighting elements), sensors (temperature sensors, pushbuttons, switches, ultrasonic sensors), and / or assembly-specific functional control units (restraint systems, infotainment, various functional control units). These electrical components are connected via the aforementioned partial wiring harness and its electrical connecting lines. Therefore, these electrical components are generally assembly-specific or installation space-specific electrical components. Each vehicle electrical system sub-zone has a partial wiring harness with connecting lines through which the electrical components are connected, namely at least one, in particular fused, power connection line for electrical power supply and at least one data connection line for data transmission.Each subzone is assigned an electronic, decentralized control unit, also referred to here as a nano zonal controller (nZC). This decentralized control unit defines an interface between a power supply line of the vehicle electrical system and the subzone. The electrical power supply and data supply to the electrical components are provided via this decentralized control unit. For this purpose, the respective control unit is connected to the subzone's partial wiring harness on one side and to the power supply line on the other. It is preferably connected to the power supply line in a pre-configured state, or alternatively to the partial wiring harness. When an interface is mentioned here, this refers to both a mechanical and an electrical interface.The decentralized control unit therefore connects the vehicle electrical system sub-zone, with its electrical components and partial wiring harness, to the power supply line mechanically, electrically, and with regard to data transmission. The partial wiring harness is preferably connected via connectors.

[0010] The individual decentralized control unit and / or the multiple decentralized control units have the following characteristics, or are designed to perform the following steps: Each decentralized control unit is connected to the aforementioned supply line, which has at least one power line for electrical power supply and at least one data line for data transmission. The supply line thus forms a central supply line, for example, in the form of a backbone, via which the decentralized control units are connected, in particular, to central units, especially a central main supply unit, specifically a main fuse box, and to a central control unit, in particular a so-called High Performance Controller (HPC).• Each decentralized control unit has a processing unit, i.e., local intelligence, designed to perform the following steps: • Communication, specifically wired communication via the data connection lines with the electrical components using a (first) data bus and a (first) data protocol. This is typically a standard bus such as Ethernet, CAN, LIN, PSI5, or SENT. Using a standard data bus allows for easy control and integration of the electrical components. • For communication between the decentralized control units, a second data bus with a second data protocol is preferably used. This is preferably, but not necessarily, a different data bus than the first, particularly one with a different data protocol.For communication between the control units, a special, proprietary communication system can be used, independent of the standard data buses still used in the vehicle electrical system. Communication with the aforementioned central control unit occurs via the power supply line. This central control unit generally controls the electrical components of the various vehicle electrical system sub-zones, either through direct control commands or at least enables their functionality. This means that decentralized control units, distributed throughout the vehicle and primarily located in the assembly modules, receive all function commands from the central control unit and execute them locally. For this purpose, the decentralized control units preferably have a gateway function that implements the bus functions required locally in the respective sub-zone.Similarly, the decentralized control units acquire local sensor data and make it available to the central control unit via the data bus. Furthermore, the decentralized control units provide local diagnostic functions regarding the status of the actuators and sensors within a sub-zone. Electrical, and in particular electronic, protection of the connecting lines of the connected vehicle electrical system sub-zone against overload and / or short circuit is also provided. The respective decentralized control unit preferably contains fuse elements or at least (electronic) switching elements designed to protect or disconnect a respective outgoing current path to a respective electrical component.Preferably, the safety elements are exclusively electronic and therefore typically reversible; no hardware safety components, such as fuses, which are usually non-reversible, are used. As an alternative to integrating safety elements into the decentralized control unit, only (electronic) switching elements are integrated, which, if necessary, are controlled by the integrated processing unit of the decentralized control unit, for example, to interrupt the respective connected current path. The decentralized control units described here are all very compact control units, each with its own housing. The use of electronic safety or switching elements minimizes the required installation space.

[0011] The decentralized control units generally form a communication network for communication among themselves and with the central control unit.

[0012] Furthermore, the central control unit is configured as a time master to specify a time signal (timestamp). In the event of the central control unit's absence or failure, one of the decentralized control units automatically assumes the function of the time master, thus becoming the new time master. A general time base is defined via the time master, to which the various participants in the communication network synchronize.

[0013] The particular advantage lies in the fact that each of the decentralized control units is specifically designed to take over the function of the time master, especially temporarily, until this function is (again) taken over by the central control unit.

[0014] If the central control unit fails or if a central control unit is (still) missing, e.g., during initial configuration, a decentralized control unit takes over the time master function. This means it identifies itself as the time master to all other (bus) participants, and especially to participants added later in the vehicle network subzone. This continues until the (dominant) central control unit has (re)activated itself.

[0015] One advantage is that in the event of a fault in a sub-zone of the vehicle electrical system or in the event of a failure of the central control unit, there is no failure of, for example, the entire system, since one of the decentralized control units for the sub-zone of the vehicle electrical system acts as a time master and thereby maintains operation, in particular an emergency operation with limited functionality with, for example, defined emergency running routines.

[0016] Another advantage is that, for example, the various participants can be configured within pre-assemblies, specifically within a sub-zone of the vehicle electrical system. Previously, this was typically only possible once the central control unit was recognized as a network participant and, acting as the time master, initiated communication with the other participants. This communication initiation can now be performed at the level of such a pre-assembly by one of the decentralized control units.

[0017] It is therefore advantageous that the vehicle electrical system is designed for sequential assembly of its sub-zones. These sub-zones, together with their connected electrical components, form the aforementioned pre-assembled modules, each with at least one decentralized control unit. The decentralized control units are designed to communicate with each other during sequential assembly, even without the central control unit. Specifically, the individual participants in the communication network configure themselves successively during the assembly process. They thus communicate with the other already installed participants. This improves and accelerates vehicle assembly. An important aspect here is that one of the decentralized control units is automatically selected as the time master, or identifies itself as such.Once the central control unit is integrated, it takes over the time master function and the other network participants then synchronize to the time base specified by it.

[0018] In a preferred embodiment, at least some, and preferably all, of the decentralized control units are connected to other decentralized control units via redundant paths. The redundant path encompasses both the power line and the data line. Therefore, if one path is interrupted, the decentralized control unit remains reliably connected via the redundant path.

[0019] One advantage of such a redundant design is that it provides multiple alternative (dynamic) data and supply paths, which is beneficial for reliability. A high degree of redundancy can be achieved with minimal effort through the clever arrangement of redundant data and supply paths. Conventional zonal structures are typically star-shaped and radiate from a central control unit. By using decentralized control units interconnected via redundant paths, the distribution structure is significantly simplified compared to a star-shaped structure, and in particular, parallel routing paths to a central distribution point are avoided.

[0020] Therefore, such a star-shaped structure has been deliberately omitted in this case. The decentralized control units are not all connected to a central control unit via their own dedicated connection. Rather, at least most of the decentralized control units are only indirectly connected to a central unit, in particular to the central control unit, for example, via nodes. Each node is one of the decentralized control units. The decentralized control units form, for example, a meshed structure and thus a meshed network.

[0021] The particular advantage of such an on-board network lies in the use of special decentralized control units and their preferred integration into the communication network, which significantly simplifies the overall network design. Compared to the previously described zonal structures with, for example, only 3-4 zonal control units, the need for additional partial cable sets and individual inline connectors is eliminated. This simplifies the assembly, design, and structure of the on-board network overall. The meshed network structure is also noteworthy, as it enables automatic self-organization of the individual components, thus simplifying retrofitting and, in particular, improving reliability.

[0022] Preferred training opportunities and other benefits result from the lower requirements.

[0023] According to a preferred further development, the control units are designed in such a way that a new control unit is automatically recognized and integrated into the communication network. For this purpose, route information stored, for example, in a so-called routing table is preferably automatically adjusted.

[0024] This measure offers the distinct advantage that the vehicle's electrical system can be functionally expanded to include additional sub-zones and / or new functionalities without requiring a (complex) cross-zone installation or integration. In particular, it allows for the retrofitting of a replacement component or an additional component (function on demand) during repairs or upgrades without having to reconfigure the entire network. This effectively enables a "plug and play" installation.

[0025] The preferred method for combining the control units is dynamic routing, which automatically adapts communication paths to changing circumstances. Dynamic routing is also known as adaptive routing. Its key advantage is that, even in the event of a failure—for example, if part of the vehicle's electrical system fails—dynamic routing can automatically compensate for a communication path and a power supply path by creating a new (redundant) communication and power supply path. This improves the reliability and fault tolerance of the vehicle's electrical system. Furthermore, the vehicle's overall electrical power management can be supported by load shedding of individual circuits, for example, within a defined terminal control system, without any additional effort.

[0026] In a preferred embodiment, the second data bus for communication between the control units differs from the first data bus. Specifically, the second data protocol of the second data bus differs from the data protocol of the first data bus. The second data bus is, in particular, a proprietary data bus. By using differently configured data buses, the manufacturer (the manufacturer of the vehicle electrical system) can establish reliable communication between the control units according to desired criteria and requirements. At the same time, the use of standard data buses for communication with the electrical components in the vehicle electrical system sub-zones, as well as for communication with at least one central control unit or at least one central power supply unit, ensures standardized and reliable data exchange.Preferably, a separate network of control units is established via this second data bus, also known as a "private network". This network preferably uses conventionally known standard protocols.

[0027] Communication with the remaining components and the rest of the vehicle's infrastructure (for example, on-board network sub-zones as well as with the central units) preferably takes place via a suitable interface, also known as a gateway.

[0028] This interface is integrated into a respective decentralized control unit. It is designed for mutual communication and, if necessary, conversion of the data protocols of the different data buses for bidirectional communication to and from the electrical components and / or the central units.

[0029] This measure ensures reliable and secure communication throughout the entire vehicle network. Since the different sub-zones also have their own proprietary networks, this measure enables and guarantees integration into the common vehicle network, which is designed as a high-performance network.

[0030] For communication, a predefined latency is determined and adhered to, so that the sum of all latencies meets the requirements of the individual systems formed by the various on-board network sub-zones.

[0031] In a preferred embodiment, each decentralized control unit is the sole, and in particular standardized, interface to the electrical components of the respective vehicle electrical system sub-zone. "Sole interface" means that the components of the respective vehicle electrical system sub-zone are connected to the rest of the vehicle electrical system exclusively via the decentralized control unit. The power supply lines and / or data supply lines of the sub-wiring harness of the respective sub-zone are connected to the decentralized control unit via one or more electromechanical interfaces, in particular connectors.

[0032] Since each sub-zone is formed by a defined assembly, this means that each assembly is connected solely via this single interface. Therefore, there are no additional data or power lines to the individual components. This significantly simplifies the overall assembly effort, as when installing a pre-assembled module, only the connection via the respective decentralized control unit for that specific vehicle electrical system sub-zone is required. For example, data communication and power supply for a door module or any of the other aforementioned assemblies are handled entirely and exclusively via the respective decentralized control unit.Especially in conjunction with self-organization via the communication network, this results in an overall simple, easy-to-assemble design of the entire on-board network with simple expansion options and low assembly requirements.

[0033] The decentralized control units also have a suitable interface for connection to the power supply line. Here, too, at least one power line and at least one data line of the power supply line are connected to the decentralized control unit via one or more electromechanical interfaces, e.g., screw terminals and / or plug-in terminals via contact connectors.

[0034] In a preferred embodiment, at least some, and preferably all, of the decentralized control units have a common, standardized electromechanical connection interface, which is designed in particular as a contact plug. The power supply line is connected via this common, i.e., uniform, connection interface. Thus, both the at least one power line and the at least one data line are connected via the common connection interface, i.e., in particular via a common contact plug. The same standard connection interface is used for each of the subnetworks. Differences exist only in the conductor cross-sections.

[0035] Preferably, several sub-cable sets are connected to at least one of the decentralized control units. These sub-cable sets are not interconnected and are located in different sub-zones. Each sub-cable set, like each individual cable set, has connecting cables (power and data) to which several electrical components are connected. The decentralized control unit therefore provides interfaces, in particular connectors, for these sub-cable sets.

[0036] The sub-cable sets supply spatially distinct areas, for example, a front bumper and a section adjoining it towards the passenger compartment. Each sub-cable set has, for example, a common wiring harness with several connecting wires, through which it is connected to the decentralized control unit, and from which individual connecting wires branch off and lead to the connected electrical components.

[0037] In a suitable further development, the vehicle electrical system includes at least one central power distributor, for example, a so-called (electronic) (main) fuse box, also known as a power distribution box, and at least one central control unit, in particular a so-called high-performance controller (HPC), to which the power supply line is connected, and to which the individual decentralized control units are in turn connected. These central units thus enable the power supply to the individual sub-zones of the vehicle electrical system as well as their control via the power supply line.

[0038] According to an advantageous embodiment, the central control unit itself is located in a subzone and is connected to the power supply line via the decentralized control unit assigned to this subzone. This results in a simple overall on-board network architecture, in which central units are also part of a subzone, allowing them to be easily integrated into the network structure.

[0039] Alternatively, the central control unit is directly integrated into the network structure and not indirectly via a decentralized control unit, and is directly connected to the supply line.

[0040] Furthermore, the central control unit also forms a decentralized control unit, i.e., it forms an interface to at least one of the vehicle network sub-zones, e.g., to a pre-assembly module.

[0041] In a preferred configuration, at least one power line and / or at least one data line of the supply chain are looped through at least some of the decentralized control units. At least some, and preferably all, of the decentralized control units each have an input and an output connection for the power line and / or data line. This looping reduces the overall wiring effort and eliminates the need for multiple parallel paths and supply chains.

[0042] Preferably, at least some, and preferably all, of the decentralized control units have exactly one connection interface for connecting to the power supply line, which can also be configured as a loop-through interface if required. This single connection interface for the power supply line typically has a first connection interface for connecting at least one power line and a second connection interface for at least one data line of the power supply line. Since there is only exactly one connection interface, possibly with a loop-through function, the decentralized control units are connected to only one power supply line. Therefore, each decentralized control unit does not have multiple connection interfaces for multiple incoming / outgoing power supplies.Each decentralized control unit therefore does not form a central node from which, for example, several connecting lines radiate outwards in a star configuration and three or more other control units are connected. The decentralized control unit is therefore connected to a maximum of two other decentralized control units.

[0043] According to further training, at least some of the decentralized control units are only connected to a maximum of one other decentralized control unit, i.e., these form quasi-decentralized end control units where no loop-through occurs.

[0044] The data line is preferably exactly one data line, in particular a two-wire data line. Alternatively, it can also be a coaxial data line. Communication and control of all electrical components take place via this single data line. A suitable addressing system is typically provided for this purpose.

[0045] In a preferred embodiment, the power supply line has exactly one conductor through which the electrical power is supplied. This single conductor has at least one conductor that is connected to a positive reference potential (positive potential) of a power source, for example, a battery, particularly via the power distribution unit. Depending on the embodiment, the single conductor may also have a second conductor for a ground connection. However, this is not strictly necessary, as the required ground connection of the individual electrical components can also be achieved, for example, via a ground connection to a vehicle structure, which provides a return path to the power source (battery). The power line is therefore either a single-core or a two-core supply line.The respective power supply for each sub-system is branched off from this central power line of the supply chain. Distribution to the various power supply lines is handled by the respective decentralized control unit. Each power supply line is preferably protected against overcurrent and / or short circuits.

[0046] In a preferred embodiment, the decentralized control units, together with the supply line, form a cascading topology, a backbone-based topology, or a hybrid topology consisting of both. In the cascading topology, several decentralized control units are arranged in series, with a first decentralized control unit preferably being followed by a group of further decentralized control units, these further decentralized control units being arranged in parallel to each other. In the backbone-based topology, several branch lines extend from a main supply line, in which a number, i.e., one or more, decentralized control units, and preferably all of these further decentralized control units, are arranged in parallel to each other.When combining both topologies, the supply line is typically looped through at least some decentralized control units.

[0047] In a suitable configuration, the vehicle electrical system has a total of more than 7, preferably more than 10, and more preferably more than 15 or even more than 20 subzones. A maximum of, for example, 40, or preferably only 30 or 20 subzones are formed. The number of individual subzones varies and depends, for example, on the vehicle class and / or equipment. The number also depends, in particular, on the extent to which the vehicle's structure is modular.

[0048] Ideally, each sub-zone of the vehicle electrical system has more than 5, preferably more than 10 or even more than 20 components. For example, the number ranges from 2 to 30 components, and particularly from 5 to 20 or 10 to 20 components to be electrically and data-wise connected.

[0049] Preferably, the decentralized control units each have a housing with several external connection interfaces for connecting to the power supply on the one hand and to the partial wiring harness of the vehicle electrical system sub-zone on the other. These connection interfaces thus provide a mechanical and electrical interface to both the power supply on the one hand and the vehicle electrical system sub-zone on the other. Connectors are preferably used exclusively for connecting to the partial wiring harness of the vehicle electrical system sub-zone. The connection to the power supply – especially for the connection to the at least one data line – is also preferably made via a plug connection. The connection of the at least one power line of the power supply to the decentralized control unit is optionally made via a plug connection or, alternatively, via a screw connection for high load requirements.Alternatively, other connection and contacting technologies are provided for connection to the supply line, e.g. direct contacting.

[0050] The decentralized control units are all relatively small units with a compact form factor. Compact form factor here means that the housing encloses an internal volume (i.e., the housing excluding external connection interfaces) of a maximum of 100 cc, and preferably a maximum of 90 cc. For example, the housing – excluding external connection interfaces – has a maximum length of 5 cm or 10 cm, a maximum height of 4 cm or 8 cm, and a maximum width of 4 cm or 8 cm.

[0051] In a preferred configuration, the decentralized control units, together with the power supply line, form a pre-assembled main electrical system assembly. The individual sub-cable sets for the various electrical system sub-zones are connected to this assembly via their respective decentralized control units. Therefore, in the first step of the electrical system manufacturing process, this main assembly is provided by the electrical system manufacturer and delivered, for example, to an assembly site for the final assembly of the vehicle. At this assembly site, the individual sub-cable sets are then mounted onto the pre-assembled modules and, if necessary, connected to the control units. The complete assembly can then be functionally tested before installation in the vehicle. During the final assembly of the vehicle, the individual electrical system sub-zones are thus connected to the vehicle's electrical system.

[0052] At least some, and preferably all, vehicle electrical system sub-zones are—as already described—preferably part of a pre-assembled module comprising a mechanical vehicle module and the vehicle electrical system sub-zone mounted thereon, along with the associated electrical components and the associated partial wiring harness. The mechanical vehicle module is, for example, a door, a tailgate, a bumper, a dashboard, a seat assembly, etc. Therefore, in general, the mechanical vehicle module includes not only the electrical units of the respective vehicle electrical system sub-zone but also other functional elements, particularly mechanical ones.

[0053] An embodiment of the invention is explained in more detail below with reference to the figures. These show, in some cases, highly simplified representations: FIG 1 a vehicle electrical system, FIG 2 a decentralized control unit as an interface between a supply line and a partial cable set, FIG 3 a block diagram representation of a section of the vehicle electrical system, FIG 4 a partial representation of a vehicle electrical system parent assembly with a cascading topology, and FIG 5 a partial representation of a vehicle electrical system parent assembly with a backbone-based topology.

[0054] In the FIG 1 The vehicle 2 shown is a road vehicle, in particular a passenger car. It has an electrical system 4, which is divided into a plurality of electrical system sub-zones 6. In the exemplary embodiment, a total of 15 electrical system sub-zones 6 are shown.

[0055] Each of these individual on-board network subzones 6 is assigned a decentralized control unit 8, which is also referred to as nZC (nano zonal controller) in the figures. A partial cable set 10, which is part of the on-board network subzone 6, is connected to each decentralized control unit 8. The on-board network subzone 6 also has several electrical components 12, which are represented in one of the depicted on-board network subzones 6 as boxes labeled S, A, E, and H, where S stands for sensor, A for actuator, E for ECU (Electronic Control Unit), and H for HPC (High Performance Controller). This HPC is a central control unit 14, which in the exemplary embodiment is integrated into one of the on-board network subzones 6.The ECU integrated in the vehicle electrical system subzone 6 is a functional control unit for a specific assembly, such as a seat assembly and, in particular, for an airbag, or a control unit for seat adjustment. Such assembly-specific control units are typically provided by a supplier / manufacturer of the assembly along with the assembly itself.

[0056] Each decentralized control unit 8 is connected on one side to the respective sub-cable set 10, via which individual electrical components 12 of the respective vehicle electrical system sub-zone 6 are supplied. On the other hand, each decentralized control unit 8 is connected to a supply line 16, which is designed for both electrical power supply and data connection.

[0057] Each on-board network subzone 6 typically has a large number of such electrical components 12, for example at least 5 or at least 10.

[0058] The individual decentralized control units 8 together form a network and are therefore designed for suitable communication with each other.

[0059] Furthermore, the letters A-H indicated in the circles have the following meaning: A: Cockpit as an example of an assembly and a vehicle network subzone 6, B: decentralized control unit 8 in the cockpit assembly, C: partial cable set 10 within the cockpit assembly, D: the individual electrical components 12 (S, A, E, H) of the cockpit assembly as previously explained, E: further decentralized control unit 8 of a further vehicle network subzone 6, wherein the further decentralized control unit 8 is arranged serially to the first decentralized control unit 8, F: (potential) backup path, which can be activated if necessary via dynamic routing in the network structure, G: the preferred, configured direct path for power supply and data exchange, H: the previously mentioned alternative backup path, if it is activated and provided for accordingly in the routing table.

[0060] An exemplary setup of a decentralized control unit 8 and its connection on the one hand to the partial cable set 10 and on the other hand to the supply line 16 is the FIG 2 to be seen. The decentralized control unit 8 generally has a housing 18, which, for example, has mounting tabs for screw fastening to a support component of the vehicle 2. Several connection interfaces 20 are formed on the outside of the housing 18, namely a first connection interface 20A for connection to a (single-core) power line 22 of the supply line 16, a second connection interface 20B for connection to a (two-core) data line 24 of the supply line 16, and one or more further connection interfaces 20C for connection of the partial cable set 10.

[0061] The supply line 16 generally comprises at least one power line 22 and at least one data line 24. The power line 22 can be a single-core or a two-core power line. In the exemplary embodiment, only a single-core power line 22 is provided. In a two-core power line 22, in addition to a supply conductor with positive reference potential, a ground conductor with ground potential is also provided. In the exemplary embodiment, the data line 24 is a twisted pair of conductors.

[0062] The two connection interfaces 20A and 20B to the supply line 16 are shown in the exemplary embodiment of the FIG 2Each interface is designed as a loop-through interface, meaning it is a two-part design with an incoming input connection and an outgoing output connection, one for the power line 22 and one for the data line 24. For interface 20A, these connections are preferably fitted with a cable lug and, for example, as screw terminals. Interface 20B preferably has a contact plug for each incoming and outgoing connection. Alternative connection options, such as direct contact, are also possible.

[0063] Alternatively to the one in FIG 2In the depicted variant, a standardized, common interface, in particular via a common connector (not shown), is provided for connecting the power line 22 and the data line 24. This common interface is preferably the same for all decentralized control units 8 – except for potentially different conductor cross-sections.

[0064] Based on the FIG 2It can also be seen that the decentralized control unit 8 has only one (single) connection interface 20 for connecting the power supply line 16, whereby this connection interface 20 is designed as a loop-through interface in the exemplary embodiment. The decentralized control unit shown can therefore be connected to a maximum of two other decentralized control units 8. Connection lines 26 of the partial cable set 10 are connected via the additional connection interface 20C. These are, on the one hand, power connection lines and, on the other hand, data connection lines. The former supply a respective electrical component 12 with current and electrical power, and the latter provide data communication and control. Several contact plugs are provided for the additional connection interface 20C in the exemplary embodiment.

[0065] For the respective connectors, corresponding sockets with suitable internal contacts are provided on the outside of the housing 18. The various connecting cables 26 are designed differently depending on the requirements. The various connecting cables 26 form the individual cables of the partial cable set 10, via which the individual electrical components 12 are connected to the decentralized control unit 8.

[0066] Inside the housing 18, a computing unit 28, shown only schematically, is integrated. This unit provides local intelligence for the decentralized control unit 8 and performs the various functions described in the introductory section. The data line 24 is also appropriately wired to the multiple data connection lines inside the housing 18, preferably with a separate data connection line for each of the electrical components 12 that are connected to the data network.

[0067] Furthermore, suitable current distribution is provided from the power line 22 of the supply line 16 to the outgoing power connection lines of the sub-cable set 10. Inside the building, safety devices, in particular electronic safety devices (not shown in detail), are arranged to protect each outgoing power connection line against excessive currents and / or short circuits.

[0068] Preferably, an electronic circuit can integrate the protection of the connecting lines, the wiring / connection of the data lines, and other functions of the computing unit (28).

[0069] Furthermore, it can be advantageous in terms of installation space and manufacturing costs if this electronic circuit is an integrated circuit, in particular an ASIC, i.e., an application-specific integrated circuit. Such an integrated circuit therefore forms the processing unit or is at least part of the processing unit.

[0070] The power line 22 of the supply line 16 is connected to an energy source and specifically to a central power distributor 29 (distribution box, see in particular FIG 3 ), in particular connected to an (electronic) main fuse box. The supply line 16 preferably, but not necessarily, integrates several power lines 22, each of which is connected to the power source via an individual (electronic) fuse in the power distribution unit 29.

[0071] FIG 3Figure 1 shows a simplified functional diagram of a section of the vehicle electrical system 4 with regard to both the data connection and the power supply: The central power supply units are the aforementioned central control unit 14 (HPC, High Performance Controller) and the distribution box 29. The central control unit 14 communicates with the individual decentralized control units 8 via a gateway 30. This communication occurs, for example, via a public data bus, such as an Ethernet data bus.

[0072] In the FIG 3Each of the individual decentralized control units 8 has a communication connection to the gateway 30. However, this is generally not a physical individual wiring connection. Rather, it is achieved via wiring through the supply line 16 and a wiring topology such as the one shown below. Figures 4 and 5 will be explained.

[0073] The individual on-board network sub-zones 6 are in FIG 3 Each component is represented in a simplified manner by a box, which is labeled differently, namely, in the exemplary embodiment, by sensor, ECU, and actuator. These labels are merely intended to indicate that the corresponding vehicle electrical system sub-zones 6 contain such electrical components 12 (among others).

[0074] Each on-board network sub-zone 6 is connected to the respective decentralized control unit 8 via at least one 26A (POWER) power connection line and is connected via this to the power line 22 of the supply line 16.

[0075] Regardless of the partially purely functional representation according to the FIG 3 In physical terms, the power line 22 and the data line 24 are each routed parallel and side by side to a respective decentralized control unit 8. In certain sections of the vehicle electrical system 4, it may be provided that individual, and thus multiple, power lines 22 and data lines 24 are routed from the central units 14, 29 to different decentralized control units 8.

[0076] However, at least in one section of the vehicle network 4, the data line 24 and the power lines 22 are looped through the individual decentralized control units 8.

[0077] Depending on the function and type of the integrated electrical components 12 in a respective on-board network subzone 6, suitable communication and data connection takes place.

[0078] Data communication with each vehicle electrical system subzone 6 takes place via a first data bus, which is a standard data bus, such as a CAN or LIN data bus. The different vehicle electrical system subzones 6 can communicate with the decentralized control units 8 via different data buses.

[0079] The different designations sensor, ECU, and actuator for the respective subzones 6 indicate different types of communication: For example, sensors only communicate and transmit data to the decentralized control unit 8. Actuators only transmit a control signal in one direction to the actuator. ECUs engage in bidirectional communication. Control signals are transmitted, for example, via pulse-width modulated signals. Since each vehicle electrical system subzone 6 typically contains different types of electrical components 12, bidirectional communication is usually established between the vehicle electrical system subzones 6 and the decentralized control unit 8. This communication generally takes place via data connection lines 26B.

[0080] The decentralized control units 8 are interconnected via a second data bus, which is specifically designed as a proprietary data bus and is separate and independent from communication with the vehicle network subzones 6 or from communication with the central control unit 14. Communication between the decentralized control units 8 is, for example, via Ethernet.

[0081] Overall, the decentralized control unit 8 is therefore equipped with a suitable (second) data bus for communication among itself and with suitable (first) data buses for communication on the one hand with the vehicle network sub-zones 6 and the electrical components 12 arranged therein, and on the other hand for communication with the central control unit 14.

[0082] The decentralized control units 8, together with the central control unit 14, generally form a communication network. Within this communication network, the central control unit 14 is regularly also configured as a time master, which provides a time signal (e.g., clock signal, timestamp) and thus a time base for the participants of the communication network.

[0083] It is important to note that if the central control unit 14 fails or is missing, one of the decentralized control units 8 automatically assumes the function of the time master and determines a time signal and thus a time base. The other participants synchronize to the new time base. As soon as the central control unit 14 (re)connects, it (re)assumes the function of the time master. The same applies when the central control unit 14 is first integrated into the communication network. This is particularly advantageous during the sequential assembly of the pre-assembled modules formed by the on-board network sub-zones 6 and the connected electrical components 6. This allows each decentralized control unit 8 to establish contact with the other network participants at a very early stage of assembly and to begin a configuration process, particularly an automated one.

[0084] This change of the time master function between the central control unit 14 and one of the decentralized control units 8 takes place in particular without the need to restart the system.

[0085] The individual decentralized control units 8 together with the supply line 16 each form a main electrical system assembly 32, which are available in different topologies and sections within the Figures 4 and 5The wiring harness base assembly can also exhibit hybrid topologies. The wiring harness base assembly 32 is, in particular, a prefabricated assembly that is delivered, for example, to an assembly site for the vehicle. During the final assembly of the vehicle, this wiring harness base assembly 32 is installed in the vehicle, and during the assembly of the individual component assemblies with the individual wiring harness sub-zones, these are subsequently connected in a simple manner to the respective decentralized control unit 8 via the connection of the partial cable set 10 to the additional connection interface 20C.

[0086] FIG 4Figure 1 shows a cascading topology in which a group of further decentralized control units 8 are arranged serially following a decentralized control unit 8, wherein in the exemplary embodiment the supply line 16 branches out and the further decentralized control units 8 are arranged parallel to each other.

[0087] FIG 5 Figure 1 shows a backbone-based topology in which the supply line 16 has a main line 16A and branch lines 16B branching off from it, wherein a number, i.e. one or more decentralized control units 8 are preferably connected in parallel or alternatively or additionally in series via each branch line 16B.

[0088] As particularly evident from the FIG 4 or the FIG 5As can be seen, each individual decentralized control unit 8 has a maximum of one further unit connected upstream or downstream. This means that each of the decentralized control units 8 is connected to a maximum of two other decentralized control units 8. For this purpose, the power supply line 16 is connected via a loop-through interface in each case. Some of the decentralized control units 8 are also designed as decentralized end control units 8, in which the power supply line 16 is not looped through and which are therefore only connected to the power supply line 16 at one end. Reference symbol list

[0089] 2 Vehicle 4 On-board power supply 6 On-board power supply sub-zone 8 Decentralized control unit 10 Partial cable set 12 Electrical component 14 Central control unit 16 Power supply cable 16A Main cable 16B Branch cable 18 Housing 20 Connection interface 20A, burst, second connection interface to power supply cable 16 20C Further connection interface to partial cable set 10 22 Power cable 24 Data cable 26 Connection cable 26A Power connection cable 26B Data connection cable 28 Computing unit 29 Power distributor 30 Gateway 32 On-board power supply main assembly

Claims

1. On-board electrical system (4) for a motor vehicle, which - has a large number of on-board network subzones (6), wherein - each subzone has several electrical components (12), - each subzone has a cable subset (10) with connection cables (26), namely power connection cables (26A) and data connection cables (26B), via which the electrical components (12) are connected, - each subzone is assigned a decentralized control unit (8) which defines an interface to the on-board network subzone (6) via which the electrical power supply as well as the data supply of the electrical components (12) is provided, and, for this purpose, the decentralized control units (8) are ∘ connected to a supply cord (16) which has at least one power line (22) for the electrical power supply and at least one data line (24) for data transmission, ∘ the decentralized control units (8) each have a processing unit (28) which is configured to carry out the following steps: ▪ communication via the data connection lines (26B) with the electrical components (12) using a first data bus, ▪ wherein a second data bus is preferably used for communication between the decentralized control units (8), ▪ communication with a central control unit (14) via the supply cord (16), ▪ electrical protection of the connected connection lines (26, 26A), characterized in that - the central control unit (14) is configured as time master for specifying a time signal, and wherein on-board network is configured such that, in the event of a lack or failure of the central control unit (14), one of the decentralized control units (8) automatically takes over the function of the time master.

2. The on-board network (4) according to the preceding claim, wherein each of the decentralized control units (8) is configured to temporarily take over the function of the time master, until the function of the time master is taken over by the central control unit (14).

3. The on-board network (4) according to any one of the preceding claims, wherein, in an initial configuration, one of the decentral control units (8) takes over the function of time master, until the central control unit (14) is switched on.

4. The on-board network (4) according to any one of the preceding claims, wherein, in case of a failure in an on-board network subzone (6), one of the decentral control units (8) for the on-board network subzone (6) acts as time master and maintains an emergency operation with a limited range of functions.

5. The on-board network (4) according to any one of the preceding claims, which is configured for sequential assembly of the on-board network subzones (6) as pre-assembly modules, wherein the decentralized control units (8) are configured, even during the sequential assembly, to also communicate with each other without the central control unit (14), wherein, to this end, an initiation of the communication on the level of such a pre-assembly module takes place by a decentralized control unit (8).

6. The on-board network (4) according to the preceding claim, wherein already during the sequential assembly, the individual participants of a communication network are successively being configured.

7. The on-board network (4) according to any one of the preceding claims, wherein the second data bus for the communication of the decentralized control units (8) among each other is different from the first data bus.

8. The on-board network (4) according to the preceding claim, wherein the second data bus is configured as a proprietary data bus.

9. The on-board network (4) according to any one of both preceding claims, wherein the respective decentralized control unit (8) is configured for a reciprocal conversion of the the data protocols of both data buses for a bidirectional communication to / from the electrical components (12).

10. The on-board network (4) according to any one of the preceding claims, wherein several cable subsets are connected to one of the decentralized control units (8), wherein the cable subsets are not connected to each other and are spatially laid in different subzones.

11. The on-board network (4) according to any one of the preceding claims, which has at least one central power distributor (29) and at least one central control unit (14) to each of which the supply cord (16) is connected.

12. The on-board network (4) according to the preceding claim, wherein the central control unit (14) is arranged in an on-board network subzone (6) and is connected to the supply cord (16) via a decentralized control unit (8), assigned to this on-board network subzone (6).

13. The on-board network (4) according to any one of the preceding claims, wherein the power line (22) and the data line (24) of the supply cord (16) are looped through at least some of the decentralized control units (8) and the decentralized control units (8) each have an input connection and an output connection for the power line (22) and / or the data line (24), wherein, in a preferred embodiment, at least some and preferably all of the decentralized control units (8) have exactly one connection interface for connecting the supply cord, which is additionally configured as a loop-through interface, if required.

14. The on-board network (4) according to any one of the preceding claims, wherein the individual decentralized control units (8), together with the supply cord (16), form a prefabricated on-board main module (32), to which the individual cable subsets (10) are connected to the respective decentralized control units (8).

15. The on-board network (4) according to any one of the preceding claims, wherein at least some and preferably all on-board network subzones (6) are each part of a pre-assembled module having a mechanical vehicle module and the respective integrated on-board network subzone (6), comprising the several electrical components (12) which are connected to the decentralized control unit (8) via the cable subset (10).