DE102007039831A1 - On-board network for a motor vehicle - Google Patents

Abstract

Generator interface unit (9 ₁ ), in particular for an electrical system (1) of a motor vehicle, which comprises a bus interface (4) and a generator (5 ₁ ), wherein the generator (5 ₁ ) is arranged, electrical energy for the electrical system (1) controlled by messages (7) received from the bus interface (4), each message (7) having an address portion (71) specifying an address of a receiver of the message (7), and wherein the bus interface (4 ) has a plurality of receiver ports each associated with an address of a set of receiver addresses and arranged to decode messages (7) whose address portion (71) specifies an address of the set and each decoded message at the address associated with its address Output to the receiver terminal, wherein the generator (5 ₁ ) is connected to one of the receiver terminals.

Description

The The invention relates to a vehicle electrical system for a motor vehicle, for example for a Commercial vehicle.

State of the art

In A vehicle electrical system must have a variety of electrical Provide consumers with sufficient electrical energy at the right time to disposal so that they can fulfill their intended functions. Here communicates a control unit in the electrical system usually with the energy-producing system and consumers, about one current state of all components to be informed and controlling to be able to intervene, bottlenecks to avoid problems in the energy generating system. The energy-generating System also interacts with performance a drive motor of the motor vehicle, since with high energy requirements part of the engine power from the electrical consumers for the Generation of electrical energy must be spent and not for the Drive the vehicle available stands. Hence comes the controller also the task, in a driving situation, in which the available engine power for example, in favor of better acceleration is to temporarily reduce energy production in the electrical system.

The Communication between consumers, control unit and a generator takes place usually over a standardized bus system, for example a LIN bus (LIN = Local Interconnect Network). For the communication with the generator is the controller for his monitoring tasks inter alia queries about a mechanical and electrical status or a generator utilization to disposal, also for his control tasks include a specification of a nominal voltage, which is to be generated by the generator in the electrical system.

specially In modern commercial vehicles are very high demands on the monitoring and Control of a functioning power supply, since compared to a car more consumers are connected to the electrical system, and thus an even higher one Energy requirement exists, and vice versa, the engine power of the commercial vehicle for load peaks be fully available got to.

Usually becomes a single in a vehicle electrical system architecture of a commercial vehicle Generator used with very high power. Such a generator is more expensive because of its size as generators, which are used in the car sector. in addition comes that commercial vehicle generators in much smaller series be made as sol che for CARS. Therefore, the manufacturing costs are relatively high, and also the is a proportion of the development costs attributable to each manufactured generator considerably higher as with car generators.

One Approach, to generators from the car sector also for To use commercial vehicles and thus to improve the cost situation is the use several smaller power generators instead of one generator with high performance. These will then be in their connection to the Electrical system and its bus system connected in parallel. To the functioning all generators over To monitor and control the communication system of the electrical system requires this, however, the provision of bus interfaces for the generators with different addresses, in particular with regard to the physical Connection to the bus system while Bus interfaces for in PKWS used generators all the same, hard-wired Address. That means that for Commercial vehicles needed In turn, interfaces are specific and accordingly expensive.

Advantages of the invention

By The present invention will be a generator interface unit for a Vehicle electrical system of a motor vehicle created, which as a single component or also in a plurality to achieve a higher power output can be connected in the electrical system, whereby the effort for the physical connections several units on the bus system not increased.

These advantages are achieved by comprising a generator interface unit, in particular for an on-board network of a motor vehicle, a bus interface and a generator, wherein the generator is adapted to generate electrical energy for the electrical system controlled by messages received from the bus interface, each Message has an address part specifying an address of a receiver of the message, and wherein the bus interface has a plurality of receiver ports each associated with an address of a set of receiver addresses, and is arranged to specify messages whose address part specifies an address of the sentence, to decode and output each decoded message at the receiver port associated with its address, the generator being connected to one of the receiver ports. If the other receiver ports are idle, the generator interface unit may be e.g. B. supply the electrical system of a car. By connecting one or more generators to the other receiver terminals, generator systems may include various services are provided for commercial vehicle electrical systems. Regardless of the number of generators connected, the generator system occupies only one physical connection point on the bus. Since the generator interface unit can be used without any adaptation both in on-board networks with a single generator and in those with multiple generators, it can be manufactured inexpensively in large quantities, both for commercial vehicles and for cars.

In An advantageous embodiment of the invention are the bus interface and the generator combined in one component. Generator interface units, where the bus interface each to control the generator the unit serves are available in the market. The bus interface Such a unit can with little effort to the functions of Address decoding for additional addresses be extended and used to control multiple generators.

Furthermore offers it in terms of universal use of the generator interface in a wiring system with one or more generators special Advantages, if any receiver connection led out of the component is. Thus, you can not only external generators connected to the generator interface unit according to the invention be over to their interface to be controlled, but the generator interface unit can itself be connected as an external generator to a similar generator interface unit with only one of these generator interface units being the interface must be connected to the bus.

So can with the generator interface unit according to the invention in a simple way, a multiple generators comprehensive electrical system for a motor vehicle be realized, which further comprises a control unit and a bus system for transmission of messages between the controller and the generator interface unit and wherein at least one external generator is connected to one of Receiver connections of the Bus interface is connected.

In front It is particularly advantageous in terms of the cost aspect if in the electrical system of the external generator part of another generator interface unit is whose bus interface is disconnected from the bus system. Thus, can the electrical system includes several generators and yet from one small number of different types of components can be constructed. It therefore makes sense if multiple generator interface units be used and preferably all generators part of such Unit are. The bus interfaces of these units then remain expediently except for one.

The Way, how the bus interface a single generator can be the same as in a conventional unit of a generator and a bus interface dedicated to this generator alone. The fact that several generators are provided, only at the design of the control unit be taken into account preferably by appropriate programming, leading the development a vehicle electrical system according to the invention, easy.

Furthermore it is advantageous if the generators are set to values at least one operating parameter to the bus interface to deliver and the bus interface has a memory which is set up is to save these values. The fact that the generators the Provide values of their operating parameters to the bus interface, this is able to centrally manage the values. So will the possibility created, the totality of generators inquiries of the Controller, about about the total utilization, errors or the like, directly through to have the bus interface answered; the controller must then do not query data from each generator individually. Thus, the Response times for Such requests of the controller be shortened considerably to the generators.

moreover is the bus interface expediently set up to continuously update the stored values.

Further Features and advantages of the invention will become apparent from the following Description of exemplary embodiments with reference to the attached Characters. Show it:

1 a schematic representation of a section of a vehicle electrical system with multiple generator interface units according to the present invention;

2 a schematic structure of a message, which receives a bus interface of the unit according to the invention via a bus system; and

3 , a section of the presentation 1 which particularly shows details of the schematic structure of the bus interface.

1 represents the schematic structure of a section of an electrical system 1 of a motor vehicle.

The electrical system 1 includes a controller 2 , a LIN bus 3 , various electrical consumers cher 6 and generators 5 whose functions are controlled by the control unit 2 over the LIN bus 3 be monitored and controlled.

Between the LIN bus 3 and the controller 2 can still be interposed another communication level, such as a CAN bus, which the control unit 2 connects to the LIN bus via a gateway. The exact bus architecture of the entire electrical system 1 should not be further elaborated here, as it is not relevant to the present invention.

In the in 1 illustrated embodiment is a bus interface 4 with a generator 5 ₁ to an interface generator unit 9 ₁ summarized in a single component. The bus interface 4 has a plurality n of receiver terminals 10 ₁ - 10 _n over which several generators 5 ₁ . 5 ₂ , ..., 5 _n with the bus interface 4 are connected. In 1 is the number n of the receiver ports and the generators 3 , it being understood that n can have basically any values> = 2 and the number of connected generators 5 may also be smaller than that of the receiver terminals 10 , The at the receiver interfaces between the bus interface 4 and the generators 5 exchanged signals can z. B. be continuous analog signals that signal the generator to generate a target voltage or an operating variable of the generator to the interface 4 Confirming. Each of the receiver ports, especially the receiver port 10 ₁ for the one in the unit 9 ₁ integrated generator 5 ₁ , is in contact 11 ₁ - 11 _n outward of the unit 9 ₁ led out.

The embodiment uses a plurality of further interface generator units 9 ₂ , ..., 9 _n , which also each have a bus interface and a generator 5 ₂ , ..., 5 _n include. At the interface generator units 9 ₂ , ..., 9 _n is the bus interface 4 not by bus 3 connected. It is therefore functionless, which is indicated in the figure by a representation with dashed outline. Conveniently, the interfaces of the interface generator units 9 ₂ , ..., 9 _n , not supplied with operating voltage and their receiver connections are characterized by high impedance. Every contact 11 _i , n> = i> 1 of the interface generator unit 9 ₁ is with a contact 11 ₁ the interface generator unit 9 _i connected. the interface 4 the interface generator unit 9 ₁ is so capable of the generators of the units 9 ₂ , ..., 9 _n to control in the same way as their own.

The bus interface 4 the interface generator unit 9 ₁ is on the LIN bus 3 connected and receive over these messages 7 from. control unit 2 , The generators 5 ₁ . 5 ₂ , ..., 5 _n are thus via the bus interface 4 connected to the LIN bus. They have different, to the LIN bus compliant addresses, which the bus interface 4 are known. The bus interface 4 assigns each connection of a generator 5 ₁ . 5 ₂ , ..., 5 _n exactly one of these addresses too.

The control unit 2 controls and monitors the power generation in the electrical system 1 not only with regard to a current energy requirement, but also taking into account a present driving situation, wherein in situations in which the entire engine power is to be available for driving the motor vehicle, the power generation is temporarily reduced.

To do this, the controller asks 2 Information about the state of the generators 5 and start the generators 5 on the specification of a target voltage U as a guideline for the generation of energy to deliver the corresponding power. The control unit 2 sends corresponding messages 7 over the bus system 3 to the interface 4 , Every message 7 is for exactly one of the generators 5 certainly. The control unit 2 are the LIN bus compliant addresses of all generators 5 ₁ . 5 ₂ , ..., 5 _n known. the interface 4 sets the message 7 in from the generators 5 processable control signals and gives them to the generators 5 out. The type of control of the generators 5 by the control signals is in this case of the selected connection to the interface 4 certainly.

A possible schematic structure of the message 7 is in 2 shown. The message 7 includes an address part 71 and a payload part 72 , For communication with one of the generators 5 specifies the address part 71 the to the LIN bus 3 compliant address of one of the generators 5 ,

The payload part 72 includes one to the generator 5 _i directed command 74 , At the command 74 it can be a control command to the generator 5 _i act with which the controller 2 an action of the generator 5 _i request, or even to a status query to the generator 5 _i with which the control unit 2 a current value R _{i of} an operating parameter of the generator 5 _i queries.

Further details on the structure and content of the message 7 are not described here because they are not relevant to the present invention.

Now receives the bus interface 4 a message 7 from the control unit 2 , which in their address part 71 an address specified in the bus interface 4 known set of addresses of all generators 5 ₁ . 5 ₂ , ..., 5 _n is included, so identifies the bus interface 4 based on this address the message 7 as for one of the generators 5i certain message, decodes it and gives it to the generator 5 _i Continue by the generator 5 _i according to the content of the message 7 via the receiver connection 10 _i controls.

The representation in 3 shows a section of the electrical system 1 out 1 , in particular with details of the schematic structure of the bus interface 4 ,

The bus interface 4 is divided into several elements and includes a receiver 41 , a transmitter 42 , a multiplexer 44 , an address generator 45 , an analog-to-digital converter 46 and a memory 8th ,

The recipient 41 has the task of a message 7 based on the data in the address section 71 as for one of the generators 5 _i identify specific message and then the in the payload part 72 contained information 74 to decode and control their further processing.

The recipient 41 owns for each of the generators 5 _i a control signal output which is connected to the generator 5 _i corresponding receiver connection 10 _i connected is. About this receiver connection 10 _i becomes one from the payload part 72 a message 7 decoded command 74 to the in the address section 71 specified generator 5 _i forwarded to cause the latter in the command 74 perform specified action.

In addition to the control signal outputs to the generators 5 ₁ . 5 ₂ , ..., 5 _n owns the receiver 41 an address output connected to an address input of the memory 8th connected is. The memory 8th is in storage areas 8 ₁ . 8 ₂ , ..., 8 _n structured, each of the memory areas 8 ₁ . 8 ₂ , ..., 8 _n exactly one of the generators 5 ₁ . 5 ₂ , ..., 5 _n is assigned and contains stored operating parameter values of the associated generator. If the message 7 from the control unit 2 a request for an operating parameter in the address part 71 the message specified generator 5 _i is, gives the recipient 41 to the address input of the memory 8th a location of that parameter in the generator 5 _i allocated memory area 8 _i corresponding address to cause the memory to send the parameter value to the transmitter 42 to hand over.

The bus interface 4 further includes a multiplexer 44 whose inputs are connected to lines of the receiver terminals 10 _i connected to the operating parameters of the generator in question 5 _i Representative analog output signals of the generator 5 _i to lead. The multiplexer 44 is from an address generator 45 controlled, which allows each of these lines to select via a zugeord nete address and their signal to the analog-to-digital converter 46 turn on. The same address is given by the address generator 45 also at the address input of the memory 8th at. The selected signal from the generator 5 _i is from the analog-to-digital converter 46 converted to a digital operating parameter value R _i and to the already from the address generator 45 selected address in the generator 5 _i allocated memory area 8i stored.

The address generator 45 is constantly addressing one of the generators 5 after another, so over the multiplexer 44 continuously output signals of all generators 5 ₁ . 5 ₂ , ..., 5 _n provided, digitized and in memory 8th be filed. Thus are in memory 8th Constantly updated values R ₁ , R ₂ , ... R _n of operating parameters for all generators 5 ₁ . 5 ₂ , ..., 5 _n ,

The transmitter 42 the bus interface 4 finally has the job in the store 8th selected data of the memory area 8 _i as values R _{i of} the operating parameters and these data in response to the message 7 on the LIN bus and thus to the control unit 2 to send.

To optimize the response times in the generator system, the receiver differentiates 41 already when decoding a message 7 during the evaluation of the command 74 whether for the generator 5i a control command or a status request is present, with which the control unit 2 a value R _{i of} an operating parameter from the generator 5 _i requests. In case of a status query, the recipient gives 41 the command 74 not to the desired generator 5 _i but gives the address of the requested parameter to the one with the memory 8th connected address line, so that the transmitter 42 Immediately without further delay is able to read the current value R _{i of} the parameter from the memory 8 _i to the control unit 2 to send. A redirect of the command 74 to the generator 5i Waiting the response time and reading and digitizing the value R _{i is} omitted in this case, since the current values R1, R2, ..., Rn always in memory 8th available. Thus, the response times within the electrical system 1 for all status requests from the controller 2 to the generators 5 be shortened considerably.

Claims (9)

Generator interface unit ( 9 ₁ ), in particular for a vehicle electrical system ( 1 ) of a motor vehicle having a bus interface ( 4 ) and a generator ( 5 ₁ ), wherein the generator ( 5 ₁ ) is set up, electrical energy for the electrical system ( 1 ) controlled by the bus interface ( 4 ) received messages ( 7 ), each message ( 7 ) an address part ( 71 ) having an address of a Recipient of the message ( 7 ), characterized in that the bus interface ( 4 ) has a plurality of receiver ports, each associated with an address of a set of receiver addresses, and arranged to receive messages ( 7 ), whose address part ( 71 ) specifies an address of the set to decode and output each decoded message at the receiver port associated with its address, to one of the receiver ports the generator ( 5 ₁ ) connected. Generator interface unit ( 9 ₁ ) according to claim 1, characterized in that the bus interface ( 4 ) and the generator ( 5 ₁ ) are combined in one component. Generator interface unit ( 9 ₁ ) according to claim 2, characterized in that each receiver terminal is led out of the component. Electrical system ( 1 ) for a motor vehicle with a generator interface unit ( 9 ₁ ) according to any one of the preceding claims, characterized in that it further comprises a control unit ( 2 ) and a bus system ( 3 ) for the transmission of messages between the control unit ( 2 ) and the generator interface unit ( 9 ₁ ) and that at least one external generator ( 5 ₂ , ..., 5 _n ) to one of the receiver ports of the bus interface ( 4 ) connected. Electrical system ( 1 ) according to claim 4, characterized in that the external generator ( 5 ₂ , ..., 5 _n ) Part of another generator interface unit ( 9 ₂ , ..., 9 _n ), whose bus interface with the bus system ( 3 ) is unconnected. Electrical system ( 1 ) according to claim 4 or 5, characterized in that the generators ( 5 ₁ . 5 ₂ , ..., 5 _n ), values (R ₁ , R ₂ , ..., R _n ) of at least one operating parameter to the bus interface ( 4 ) and the bus interface ( 4 ) a memory ( 8th ), which is set up, the values (R ₁ , R ₂ , ..., R _n ) of the generators ( 5 ₁ . 5 ₂ , ..., 5 _n ) store. Electrical system ( 1 ) according to claim 6, characterized in that the bus interface ( 4 ) is set to continuously update the stored values (R ₁ , R ₂ , R _n ). Electrical system ( 1 ) according to claim 6 or 7, characterized in that the bus interface ( 4 ), a request from the controller ( 2 ) according to the value (R _i ) of the operating parameter of one of the generators ( 5 _i ) with the value stored for this generator. Electrical system ( 1 ) according to one of claims 4 to 8, characterized in that the bus system ( 3 ) is a LIN bus.