WO2016110352A1

WO2016110352A1 - Method for monitoring a vehicle electrical system

Info

Publication number: WO2016110352A1
Application number: PCT/EP2015/076396
Authority: WO
Inventors: Matthias Horn; Christian Bohne
Original assignee: Robert Bosch Gmbh
Priority date: 2015-01-08
Filing date: 2015-11-12
Publication date: 2016-07-14
Also published as: CN107110896B; EP3243084A1; CN107110896A; DE102015200121A1

Abstract

The invention relates to a method for operating a vehicle electrical system comprising multiple vehicle-electrical-system paths and to a vehicle electrical system configured to carry out said method. According to the invention, diagnostics are carried out by means of a component that is associated with a number of the vehicle-electrical-system paths.

Description

Description title

Method for monitoring a vehicle electrical system

The invention relates to a method for monitoring a vehicle electrical system and such a vehicle electrical system. The electrical system is provided in particular for a motor vehicle.

State of the art

Under an electrical system is to be understood in the automotive use, the totality of all electrical components in a motor vehicle. Thus, this includes both electrical consumers and supply sources, such as batteries. In the motor vehicle care must be taken to ensure that electrical energy is available in such a way that the motor vehicle can be started at any time and that sufficient power is available during operation. But even when parked, electrical consumers should still be operable for a reasonable period of time, without a subsequent start being impaired.

It should be noted that due to the increasing electrification of

Aggregates and the introduction of new driving functions, the requirement for the reliability of the electrical energy supply in the motor vehicle steadily increases. Furthermore, it has to be considered that in the future with a

highly automated driving should be permitted to a limited extent. A sensory, regulatory, mechanical and energetic fallback by the driver in this case is limited. Under a highly automatic driving, which is also referred to as highly automated driving, an intermediate step between an assisted driving in which the driver is assisted by assistance systems, and an autonomous driving in which the vehicle drives automatically and without the driver's intervention to understand. In this case, the vehicle has its own intelligence that could plan ahead and take over the driving task, at least in most driving situations. Therefore, in a highly automatic driving the electrical supply has not previously known in the motor vehicle safety relevance.

Today's conventional 14 V electrical system with only one generator and only one battery can no longer meet the increased demands on the reliability of the electrical supply sufficiently. As an example, mention is made of sailing with the internal combustion engine switched off. During the sailing phase, the generator is no longer available as an energy generator. The failure of the battery in the sailing phase therefore leads to failure of the entire electrical supply in the vehicle. For this reason, currently 14 V-vehicle electrical systems with two batteries, so-called 2-battery systems, at

Car manufacturers and suppliers for sailing discussed.

On-board network topologies for increased reliability based on a 14 V on-board network are known, in which scalable and modular on-board network topologies for supplying safety-relevant electrical consumers are realized. In these consumers are divided into consumer groups with different security relevance, in principle, a two-channel electrical supply for redundant, security-relevant consumers and a fault-tolerant supply for simply existing security-relevant consumers are provided.

In addition to the further development of the 14 V electrical system is from

Automobile manufacturers planned the introduction of the 48 V / 14 V electrical system. This 48 V / 14 V electrical system is used in addition to the supply of high-power consumers as entry-level hybridization. The publication DE 198 55 245 B4 describes a redundant power supply for electrical consumers in a vehicle electrical system. In this case, existing consumers are supplied redundantly from two sub-board networks with different voltage, including a supply of two separate voltage branches is provided.

From the document DE 10 2006 010 713 B4 a vehicle electrical system for a vehicle with at least one safety-relevant consumer is known. In this case, a simply existing security-relevant consumer is supplied redundantly from two subnetworks, a primary network and a secondary network.

Disclosure of the invention

Against this background, a procedure with the characteristics of the

Claim 1 and an arrangement according to claim 10 presented.

Embodiments result from the dependent claims and the description.

It is thus considered a vehicle electrical system that includes several sub-electrical systems, which are also referred to herein as vehicle electrical system paths. In addition, a can

Base board network be provided. In the electrical system now components, such as, consumers, DC-DC converters, etc., are provided. These components may be associated with one or more or even all of the vehicle electrical system paths. This means, for example, that the component is provided in several of the vehicle electrical system paths or couples them together. In particular, safety-relevant consumers can be constructed redundantly, i. H. These are, for example, provided in duplicate, with both consumers being able to fulfill the assigned function alone. This means that a consumer is distributed over two channels or vehicle electrical system paths.

Such a consumer can now carry out a diagnosis in both vehicle electrical system paths and compare the results determined in the diagnoses with each other. In this way, a failure, eg. By under- or

Overvoltage, or an impairment of one of the two electrical systems paths are detected and it may be initiated countermeasures if necessary. In addition to particularly safety-relevant, redundantly provided

Consumers can also be arranged in the electrical system coupling elements, for example. DC-DC converter, are used, since these electrical system paths, between which they are arranged, can monitor. Is a

Coupling element connected between a vehicle electrical system path A and a vehicle electrical system B, it is spoken herein that the coupling element is provided in both vehicle electrical system paths.

With the presented method is achieved, the state of several

To diagnose vehicle electrical system channels and to communicate this condition to other consumers or regulators. Thus, in the case of a multichannel vehicle electrical system, a superordinate diagnostic instance is present which determines the state of the

detects safety-relevant vehicle electrical system channels.

The diagnosis may, for example, show that a vehicle electrical system path has been impaired or even failed. Furthermore, unwanted galvanic couplings, for example. Between two electrical system paths, can be detected.

It should be noted that in particular in electric vehicles and hybrid vehicle electrical systems can be used in which on the high-voltage side no generator, but an electric machine or a battery can be provided. Further advantages and embodiments of the invention will become apparent from the

Description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the present invention.

Brief description of the drawings

FIG. 1 shows an embodiment of a vehicle electrical system. FIG. 2 shows a further embodiment of a vehicle electrical system.

Figure 3 shows a simplified representation of the structure of a consumer.

FIG. 4 shows an embodiment of a safety-relevant consumer in a simplified representation.

Embodiments of the invention

The invention is schematically illustrated by means of embodiments in the drawings and will be described in detail below with reference to the drawings.

Figures 1 and 2 show examples and simplified topologies of electrical systems, such as those used, for example, in motor vehicles.

FIG. 1 shows a vehicle electrical system, which is designated overall by the reference numeral 10. This comprises a base on-board network 12 with a starter 14, a generator 16, a battery 18 and a consumer R3 20. Furthermore, a first coupling element 22, for example a DC-DC converter, a first battery 24 and a first consumer Rl 26 and a second coupling element 28th , For example, a DC-DC converter, a second battery 30 and a second consumer 32 are provided.

In this case, the base on-board network 12 with the non-safety-relevant consumption R3 20 and additionally a first on-board power supply 34 and a second on-board power supply 36 are provided which are each coupled via their own coupling element 22 or 28 and via their own battery 24 or 30 or . Have an electrical storage and safety-related, redundant consumers Rl 26 or R2 32. The consumers Rl 26 and R2 32 are provided to perform the same function.

FIG. 2 shows a vehicle electrical system, which is designated overall by the reference numeral 40. This includes a baseboard network 42 with a starter 44, a generator 46, a battery 48 and a consumer 50. Furthermore, a coupling element 52, a first battery 54, a first consumer Rl 56 and a second consumer 58 are provided.

Figure 2 shows a variant of the embodiment of Figure 1 with a

safety-relevant vehicle electrical system 60 with the battery 54 and the first consumer 56, which may also represent a consumer group, which is decoupled via the coupling element 52 from the base vehicle 42 and thus is independent of this. A second safety-related vehicle electrical system path 62 with the second consumer R2, which is possibly given by a consumer group, is connected directly to the base on-board network 42.

Both of the topologies shown in Figures 1 and 2 have in common that there is a group of security relevant consumers that are redundantly designed and distributed to two separate channels. These are referred to herein as R1 and R2. In the case of highly automatic driving, these are, for example, the brake and the steering, which must be available redundantly.

This ensures that if one of the on-board power supply channels or the channel fails, the other is still available. Of particular importance is to be able to recognize the failure of a channel and the defective channel of

decoupling functioning electrical system. This is where the proposed process comes in.

In today's on-board networks, the recording of the on-board network status is distributed among the individual components. For example, the battery sensor of the consumer, for example the ESP or the electric steering, measures the vehicle electrical system voltage. However, there is no superordinate component that can detect the state of both channels, for example in the case of two-channel systems.

An example of a safety-relevant redundant load can be seen in simplified form in FIG. 3, which is designated by the reference numeral 80. In this all elements including energy supply and communication are doubled. This means that if one channel fails, the other channel alone can ensure safe operation. The illustration shows a first signal electronics 82, a second signal electronics 84, a first main controller 86, a second main controller 88, a first output stage 90, a second output stage 92, a first motor 94 and a second motor 96. Furthermore, with double arrows, a first communication 98, a second communication 100 and an internal communication line 102 illustrates. Arrows show a first port 104 to a first one

On-board electrical system and a second terminal 106 to a second electrical system path. In the illustration, components of a controller 110 and a motor 112 are labeled with borders.

The consumer 80 shown in FIG. 3 could be a steering system or

Brake system, d. H. the motor 112 controls a safety relevant system. In this redundant consumer 80, both the

Signal electronics 82 and 84, the main controller 86 and 88, the power amplifiers or power output stages 90 and 92 and the motor 112 is present twice. Also, the ports 104 and 106 to the electrical system paths and the communication 98 and 100 are provided in duplicate. Thus, in case of failure of a component or a vehicle electrical system or channel in one half, the other half redundant assume the function.

The above boxes 82, 86, 90 and 94 represent one of

Consumers from the group Rl in Figure 1 or 2, the boxes 84, 88, 92 and 96 shown below represent a consumer from the group R2. Internally, the two parts 116, 118 are connected to each other via the internal communication line 102. The two parts 116, 118 are thus parts 116, 118 of a component in the electrical system, in this case parts 116, 118 of the redundant consumer 80.

In the presented method is now provided that several

Onboard network paths or subnets are monitored by an on-board network component that is connected to several subnets. For this purpose, two basic embodiments are conceivable:

1. To use a consumer from the group of redundant existing consumers (Rl and R2) for the detection of the electrical system state, since These consumers are present through its parts on both vehicle electrical system channels and thus can compare the voltage quality of the two channels. In the concrete example, the redundant load mentioned in FIG. 3 could monitor the first on-board power system path and the second on-board power system path, and the

Share diagnostic results via the internal communication line. Is the

Voltage quality in the first electrical system path 1 worse than in the electrical system path 2, the consumer would turn off Rl above and take over the consumer R2 below the function. 2. The or the coupling elements, eg. DC-DC converter, for the

Diagnose the subnets and the base board network to use. This means that, for example, in FIG. 2, the coupling element can monitor and compare the state of the base on-board network and of the safety-relevant subnetwork. In the event of a fault on the side of the base-board network, the DC-DC converter can thus decouple the safety-relevant vehicle electrical system from the base on-board network with the consumer Rl. Thus, the group of safety-relevant consumer Rl would be supplied from the memory Bl.

An advantage of the described method is that existing components in the electrical system are used for monitoring the subnetwork, in which they are functionally expanded. As a result, the integration effort in the wiring harness is reduced for the OEM (original equipment manufacturer) and the components have a multiple benefit or unique selling point feature.

Figure 4 shows the example of a consumer, which is designated by reference numeral 120, the necessary changes to the control unit.

The illustration shows a first signal electronics 122, a second

Signal electronics 124, a first main controller 126, a second

Main controller 128, a first output stage 130, a second output stage 132, a first motor 134 and a second motor 136. Furthermore, with double arrows, a first communication 138 to the state of a first electrical system path, a second communication 140 to the state of a second electrical system path and an internal communication line 142 for comparing the states of Bordnetzpfade clarified. Arrows branch a first terminal 144 to a first vehicle electrical system path and a second terminal 146 to a second

Board network path. In the illustration, components of a controller 150 and a motor 152 are labeled with borders. Reference numerals 156 and 158 designate parts of the redundant load 120.

The following steps are now provided:

The input voltage of the respective electrical system paths is measured and read from the respective signal electronics 122 above and 124 below. The voltage measurement can be done in a known manner. On the basis of various diagnostic methods it is evaluated whether the corresponding

Onboard network path has failed or degraded. Furthermore, a coupling between two channels or the coupling of a channel to ground can be determined.

The diagnosis result can be arranged via the centrally arranged

Communication line 142 the other part

be communicated. It depends on which part, above or below, takes over the further function.

In this way, the following errors can be detected:

• Failure of a channel:

- static undervoltage, z. B. less than 9V

- Static overvoltage, z. B. greater than 16V

- Dynamic undervoltage, z. B. 10 ms less than 6V

- Dynamic overvoltage, z. B. 10 ms greater 19 V

• Time or dynamic limitation of one or both channels:

- Time limit: Voltage permanently at 12 V (failure

DC converter) • Unintentional galvanic coupling of the channels with each other:

- Are the voltage channel 1 = channel 2, even when switching on

For consumers or if one of the converters is active and the other is inactive, the channels may be galvanically connected due to an insulation fault.

This must be recognized in order to encapsulate the error if necessary.

• Unintentional coupling of one / both channels to the base on-board network: - The galvanic coupling with the base on-board network can be used for the topology in the

Figure 1 can be detected only on the respective DC-DC converter

In the case of the topology shown in FIG. 2, the galvanic coupling between the base on-board network and the safety-relevant subnet can be effected both via the DC-DC converter and via a redundant network

safety-relevant consumers are detected.

Again, it can be checked if the condition voltage is channel 1 =

Voltage channel 2 is permanently fulfilled. Finally, the on-board network state could other, z. B. safety relevant,

Consumers, a superordinate energy management, others

On-board network subscribers, such as, for example, coupling elements, memory, sources, or the driver to be notified. Draus other measures can be derived, for example, the opening of coupling elements, increasing the power of energy sources, the connection or disconnection of other electrical system loads.

Claims

claims

1. A method for operating a vehicle electrical system (10, 40), the at least two electrical systems paths (34, 36, 60, 62), wherein in the electrical system (10, 40) a plurality of components are provided, wherein a diagnosis with at least one of Components is performed, which is assigned to several of the vehicle electrical system paths (34, 36, 60, 62).

2. The method of claim 1, wherein the diagnosis is performed with a component, each comprising at least a part (116, 118, 156, 158) in different Bordnetzpfaden (34, 36, 60, 62), wherein a

Communication takes place via an internal communication line (102, 142) between the parts.

3. The method of claim 2, wherein as components consumers (26, 32, 56, 58, 80, 120) are provided, wherein the diagnosis is performed with at least one of the consumers in several of the vehicle electrical system paths (34, 36, 60 , 62) is provided.

4. The method of claim 3, wherein the consumers (26, 32, 56, 58, 80, 120) are associated with different security levels.

5. The method of claim 1, wherein as components at least one coupling element (22, 28, 52) between two board power supply paths (34, 36, 60, 62) is provided, wherein the diagnosis with at least one of the at least one coupling element (22, 28 , 52), which is used in several of the

Onboard power paths (34, 36, 60, 62) is provided.

6. The method according to any one of claims 1 to 5, wherein the diagnosis based on the measurement of input voltages of the vehicle electrical system paths (34, 36, 60, 62) is performed, which of the vehicle electrical system paths (34, 36, 60, 62) is active.

7. The method according to any one of claims 1 to 6, which is used to detect a temporal or dynamic limitation of one of the vehicle electrical system paths (34, 36, 60, 62).

8. The method according to any one of claims 1 to 7, which is used to detect a failure due to under- or overvoltage of one of the vehicle electrical system paths (34, 36, 60, 62).

9. The method according to any one of claims 1 to 8, which is used to detect an unwanted galvanic coupling.

10. Vehicle electrical system for a motor vehicle, which is set up in particular for carrying out a method according to one of claims 1 to 9, with at least two electrical system paths (34, 36, 60, 62), wherein in the electrical system (10, 40) a plurality of components are provided wherein at least one of the components associated with a plurality of the vehicle electrical system paths (34, 36, 60, 62) is arranged to perform a diagnosis.

11. The electrical system according to claim 10, wherein the diagnosis is to be carried out with a component which in each case comprises at least one part (116, 118, 156, 158) in different vehicle electrical system paths (34, 36, 60, 62), wherein a