Vehicle control unit for controlling and supplying power to one or more consumers

Abstract

Vehicle control unit for controlling and supplying power to multiple consumers (28, 29, 30), comprising a plurality of supply inputs (21, 23) for connection to a respective control unit-external partial power source (12, 14), each of which need not be able to supply the vehicle control unit with power on its own, wherein a current limiting circuit (22, 24) is directly connected downstream of each supply input (21, 23), wherein the current limiting circuits (22, 24) are configured to limit the current (I1, I2) at a respective supply input (21, 23) to a maximum permissible current (I1 max , I2 max) of the respective control unit-external partial current source (12, 14) connected to the supply input (21, 23), wherein a computing and control unit (26) is provided which determines the current (I1, I2) flowing at a respective supply input and prevents the switching on of one or more predetermined consumers (28, 29, 30) if no current flow can be detected at one of the supply inputs.

Description

[0001] The invention relates to a vehicle control unit for controlling and supplying power to one or more consumers.

[0002] Control units require a power source to operate. The power consumption of a control unit depends on its function and the components it contains. Another control unit can also serve as a power source for a control unit being powered. For example, a controllable semiconductor switching element can supply power to a power input of the control unit being powered. In this case, the semiconductor switching element acts as the power source. However, this is only possible without limitations if the current supplied by the power source can exceed the maximum current required by the control unit being powered when all its components are operating simultaneously.

[0003] If the maximum current requirement of the control unit being powered exceeds the current supplied by a power source, the shortfall must be covered by another power source. This other power source could, for example, be another controllable semiconductor switching element of the powering control unit. However, this presents the problem that if one power source fails, it will typically shut down, overloading the remaining power source. This could lead to damage or destruction of the powering control unit. Such a malfunction is unacceptable in a motor vehicle environment for both economic and safety reasons.

[0004] DE 10 2009 027 234 A1 discloses a control device for a high-current electrical consumer, in particular a starter control for a starter motor in motor vehicles, which can be adapted to different total ohmic resistances by means of an adaptation device. In one embodiment, the device uses several parallel-connected current paths with circuit breakers and current limiting devices to control the current in a targeted manner.

[0005] DE 10 2009 046 796 A1 discloses a circuit arrangement with a current-limiting device that can be supplied from two different energy sources at supply inputs of the current-limiting device in order to supply current to a load (starter motor). Switching the switching device serves to vary the current limiting in order to operate the load at different power levels during a start-up phase and in one of the subsequent phases.

[0006] German patent DE 10 2006 057 249 A1 discloses a power distribution unit for vehicle electrical systems, which includes several external power sources to ensure the reliability of the power supply to multiple electrical consumers. It is unclear whether the power sources are designed to supply the power distribution unit with power on their own.

[0007] German patent DE 10 2012 101 502 A1 discloses a current source control device in which a specific current source is assigned to each load. The failure of a current source thus leads directly to the failure of the corresponding load.

[0008] DE 10 2004 057 690 A1 describes the connection of a boost converter downstream of a current limiter circuit.

[0009] The object of the present invention is to provide a vehicle control unit for controlling and supplying power to multiple consumers, which is structurally and / or functionally improved. A further object of the invention is to provide a vehicle electrical system which is structurally and / or functionally improved. In particular, damage to the power sources supplying the control unit should be prevented during operation if a fault occurs in the power supply.

[0010] This problem is solved by a vehicle control unit according to the features of claim 1 and a vehicle electrical system according to the features of claim 5. Advantageous embodiments are set out in the dependent claims.

[0011] A vehicle control unit for controlling and supplying power to multiple consumers is proposed, comprising a plurality of supply inputs for connection to a respective external power source, none of which needs to be capable of supplying power to the vehicle control unit on its own. A current limiting circuit is directly connected downstream of each supply input. The current limiting circuits are designed to limit the current at each supply input to the maximum permissible current of the respective external power source connected to that input. According to the invention, a processing and control unit is provided which determines the current flowing at each supply input and prevents one or more predefined consumers from being switched on if no current flow is detectable at one of the supply inputs.

[0012] In the event of a failure of one of the power sources, the remaining power source(s) will not be overloaded. While this will mean that the vehicle control unit will no longer have sufficient power for its full functionality, its operation may still be possible, albeit with limitations.

[0013] The maximum permissible current at a single power input is insufficient to simultaneously supply all consumers connected to the control unit. This means that the vehicle control unit's power supply is ensured by means of multiple partial power sources at the majority of the power inputs.

[0014] In one embodiment, the current limiting circuits are coupled to each other on the output side to supply power to the consumer(s). In other words, there is no direct assignment of individual consumers to specific power inputs. The current supplied at the various power inputs is "combined" within the vehicle control unit, so that all consumers supplied by the vehicle control unit are powered from a single internal power source. This approach simultaneously increases the availability of the vehicle control unit. If individual consumers were assigned to a power input, the functionality of that consumer would cease if the power supply to that input failed.In the present case, if a power source fails, only a smaller amount of electricity is available, so that under certain circumstances individual functions may be restricted or not all consumers can be operated at the same time.

[0015] In particular, it may be provided that the interconnected current limiting circuits are connected to the load(s) via one or more boost converters. This allows the voltage level required by the respective load(s) to be provided.

[0016] According to the invention, the control unit comprises a processing and control unit that determines the current flowing at a respective supply input. A corresponding current measuring device can, for example, be included in a current limiting circuit. The corresponding current value is then transmitted to the processing and control unit for further evaluation or queried by it. The determination could also be performed by the processing and control unit itself.

[0017] According to the invention, the computing and control unit is designed to control the switching on and off of the consumer(s). The switching on and off of the consumer(s) can then occur, for example, not only depending on a user command or a corresponding command from a higher-level control unit, but also depending on the current available to the vehicle control unit.

[0018] According to the invention, the computing and control unit is designed to prevent one or more predefined loads from being switched on if no current flow is detectable at one of the supply inputs. Which loads are not switched on by the computing and control unit in such a case can be stored in a memory of the computing and control unit by means of configuration.

[0019] The invention further proposes a vehicle electrical system comprising a control unit of the type described above and at least one further electronic component, wherein each of the components is connected to a terminal of an energy storage device and comprises one or more outputs, each of which can be operated as a power source, and wherein each output is connected to an associated supply input.

[0020] In such a vehicle electrical system, the vehicle control unit described above can be supplied by several partial power sources. These partial power sources can be contained in a single electronic component or in different electronic components. The at least one additional electronic component can, for example, be a conventional vehicle control unit, which may have a semiconductor switching element output that can function as a power source. The proposed vehicle electrical system offers the same advantages as those already described above in connection with the vehicle control unit according to the invention.

[0021] In one configuration of the vehicle's electrical system, the current available at each output of at least one additional electronic component can be less than the current required for the intended operation of the control unit. By providing multiple electronic components, the maximum current required by the vehicle's control unit can ultimately be supplied.

[0022] In summary, it is proposed to use multiple partial power sources, such as outputs from semiconductor switching elements of other control units or electronic components, to supply power to the vehicle control unit. The individual partial power sources do not need to be capable of supplying power to the vehicle control unit on their own. This offers the advantage that, regardless of the maximum current requirement of the vehicle control unit, a separate power supply is not necessary; instead, various power sources already present in the vehicle can be used to supply the vehicle control unit.

[0023] This allows modular components to be used to power the vehicle's electronic control unit (ECU). No special power supply solutions need to be developed for ECUs that have a power requirement exceeding that of a single power source. This also means that a so-called base load on the power supply components does not occur. The ECU does not experience any functional limitations; that is, even if one power source fails, no individual function of the ECU will be affected. Only the overall functionality may be limited at the same time. Despite this limited functionality, the availability of the ECU can actually be increased through redundant power supply using multiple power sources.

[0024] The invention is explained in more detail below with reference to exemplary embodiments shown in the drawing. The drawing shows: Fig. 1 a first embodiment of a vehicle electrical system according to the invention with a vehicle control unit according to the invention for controlling and supplying power to several consumers, and Fig. 2 a second embodiment of a vehicle electrical system according to the invention.

[0025] Fig. Figure 1 shows a first embodiment of a vehicle electrical system according to the invention. Shown are an electronic component 10 and a vehicle control unit 20 (hereinafter referred to as control unit 20) supplied with power by the electronic component 10. The component 10 represents, for example, another control unit of the vehicle electrical system. It is not necessary for the component 10 and the control unit 20 to have a functional relationship to each other. This means that the functions provided by the component 10 and the control unit 20 do not need to influence or depend on each other. It should be emphasized that such a functional relationship can, of course, also exist.

[0026] Component 10 is connected to a battery terminal 1 at a supply input 15. In addition to functional components not shown in detail, component 10 includes, for example, two controllable semiconductor switching elements 12, 14, which are connected between the supply input 15 and each of its associated output 11, 13. The controllable semiconductor switching elements 12, 14 each constitute a current source. The magnitude of the current I1, I2 that can be supplied by the controllable semiconductor switching elements 12, 14 depends on the type and configuration of the semiconductor switching elements. For example, the maximum current I1 that can be supplied by the semiconductor switching elements 12, 14 is max , I2 max 8 A each. It is understood that the maximum current that can be supplied by the semiconductor switching elements 12, 14 can also have different levels.

[0027] To prevent damage to the semiconductor switching elements 12, 14 due to a sustained or temporary excessive current, the semiconductor switching elements typically have safety circuits. An excessive current then leads to the shutdown of the affected semiconductor switching element. An excessive current through a semiconductor switching element can be detected, for example, by a corresponding temperature increase resulting from the excessive current flow.

[0028] In this embodiment, the control unit 20 is intended to have a maximum current draw of 12 A when all consumers 28, 29, 30 connected to the control unit 20 are operating simultaneously. The intended functionality of the control unit 20 is therefore only fulfilled if the control unit 20 is supplied with a current of at least 12 A. It is readily apparent that the intended functionality of the control unit 20 could not be provided by only one of the current sources 12, 14 of the supplying component 10.

[0029] The control unit 20 therefore has, for example, two supply inputs 21, 23. Each of the supply inputs 21, 23 is connected to an assigned output 11, 13 of the supplying component 10. As shown from Fig. As can be easily seen, output 11 is connected to supply input 21 and output 13 to supply input 23. In total, the control unit 20 can thus receive I1 from the two power sources 12 and 14. max + I2 max = 8 A + 8 A = 16 A must be provided so that the intended functionality is enabled.

[0030] Each of the supply inputs 21, 23 of the control unit 20 is directly connected to a current limiting circuit 22, 24. The current limiting circuits 22, 24 are designed to limit the current I1, I2 at the respective supply input 21, 23 to the maximum permissible current I1. max , I2 maxto limit the current source connected to the relevant supply input 21, 23, here the controllable semiconductor switching elements 12, 14. This has the effect that in the event of a fault that deactivates one of the semiconductor switching elements 12, 14 (e.g. by the safety circuit mentioned above), the other current source cannot be overloaded and damaged by excessive current draw from the control unit 20.

[0031] Current limiting circuits can be implemented in various ways familiar to those skilled in the art. For example, the current limiting circuit can be provided using a pulse-width modulated switching element and a comparator.

[0032] On the output side, the current limiting circuits 22, 24 are connected in the exemplary embodiment to a boost converter 25, for example a DC booster. The boost converter 25 is coupled to an output 27 of the control unit, to which, for example, three loads 28, 29, 30 are connected. The number of loads in the exemplary embodiment of Fig. The number of three consumers 28, 29, 30 connected to control unit 20 is arbitrary. A smaller or larger number of consumers could just as easily be connected to control unit 20. Likewise, a larger number of boost converters could be provided. For example, each consumer could be assigned its own boost converter.

[0033] The control unit 20 further comprises a computing and control unit 26. The computing and control unit 26, which is, for example, in the form of a microprocessor in the control unit 20, serves to switch the consumers 28, 29, 30 on and off by means of respective control signals s28, s29, s30. How and for what reasons the control signals s28, s29, s30 are generated during the intended operation of the control unit 20 is of minor interest for the present invention, so that this will not be discussed in more detail here.

[0034] The processing and control unit 26 is further configured to determine the current I1, I2 flowing at each respective supply input 21, 23. For this purpose, a suitable current measuring device can be included in the respective current limiting circuit assigned to the supply input 21, 23. Alternatively, the current measuring device can also be included in the processing and control unit 26. A corresponding current value is transmitted in a signal s1(I1), s2(I2) from the respective current limiting circuit 22, 24 to the processing and control unit 26 or queried by it.

[0035] Based on the information about the current value at the supply inputs 21, 23, the processing and control unit 26 can determine whether one of the current sources 12, 14 is defective and therefore not supplying current to the relevant supply input 21, 23. In the embodiment described above, this would mean that if one of the semiconductor switching elements 12, 14 fails, the control unit 20 could only be supplied with a maximum current of 8 A. The current limiting circuit 22, 24 of the still supplied supply input 21, 23 limits the maximum input current to this maximum permissible value for the current source, as described above.

[0036] In such a (fault) event, the computing and control unit 26 can restrict (degrade) the functionality of the control unit 20. For example, the output of the control signals s28, s29, s30 is modified so that the consumers 28, 29, 30 cannot be switched on at the same time, as the required current cannot be supplied (in the exemplary embodiment, the maximum 12 A is required when all consumers 28, 29, 30 are operated simultaneously). Instead, for example, only the most important consumers are switched on. Or the consumers 28, 29, 30 are switched on at different times. The way in which the function of the control unit 20 is modified can be predefined in the computing and control unit 26.

[0037] In the Fig. In the embodiment shown in Figure 1, the partial current sources required to supply the control unit 20 are arranged in the form of the controllable semiconductor switching elements 12, 14 in a common electronic component 10. In contrast, Figure 1 shows... Fig. 2 another embodiment, which differs from the one in Fig. The embodiment shown in 1 differs only in that the partial current sources, again in the form of two controllable semiconductor switching elements 12, 14, are arranged in two different electronic components 10a, 10b.

[0038] The respective supply inputs 15a and 15b of components 10a and 10b are connected to battery terminal 1. The controllable semiconductor switching element 12 of component 10a is connected between its supply input 15a and output 11. Similarly, the controllable semiconductor switching element 14 of component 10b is connected between its supply input 15b and output 13. Components 10a and 10b can have independent functionalities with respect to each other and with respect to the control unit 20. The functions of components 10a and 10b and the control unit 20 can also be related to each other.

[0039] It is clear to an expert that the control unit 20 supplied in the manner described above could also have a larger number of supply inputs, which are supplied by power sources from one or more components.

[0040] The proposed approach has a number of advantages.

[0041] The control unit is powered simply by adjusting the input circuitry with a number of current limiting circuits corresponding to the supply inputs. The electronic components within the control unit require only minor modifications. In particular, the loads connected to the control unit do not need to be individually assigned to the individual supply inputs, which would result in functional limitations.

[0042] As shown in the exemplary embodiments, the control unit can manage with a single boost converter.

[0043] In the event of a fault in one of the power sources, the fault is detected by the processing and control unit contained within the control unit due to the limited power supply. This allows the functions of the control unit to be reduced to the necessary minimum.

[0044] Another advantage is that the power supply components do not need to be modified. Components with a power supply output can be used. If the current supplied by a component's power supply output is insufficient to power the control unit as intended, any number of power supply components can be connected to a power input of the control unit to supply it.

[0045] Although the input circuitry of the control unit needs to be adapted, the actual electronic components remain functionally identical to those required with a dedicated power supply. Therefore, no functional limitations are incurred. On the contrary, operational availability even increases due to the redundant power supply, as the processing and control unit can selectively decide which components are switched off in the event of a power supply failure and which are not.

[0046] Furthermore, supplying the control unit from other vehicle components offers the advantage that the control unit does not need to be permanently connected to a battery terminal. This helps avoid problems caused by moisture. Reference symbol list 1 battery terminal 10 electronic components 10a first electronic component 10b second electronic component 11 first exit 12 first switching element (power source) 13 second exit 14 second switching element (power source) 15 Power supply input of the electronic component 15a Supply input of the first electronic component 15b Supply input of the second electronic component 20 Control unit 21 First supply input of the control unit 22 first current limiting circuit 23 Second supply input of the control unit 24 second current limiting circuit 25 DC boosters 26 Calculation / Control Unit 27 Output of the control unit 28 first consumer 29 second consumer 30 third consumers I1 first current I2 second current s1(I1) first signal with information about the magnitude of the first current I1 s2(I2) second signal with information about the magnitude of the first current I2 s28 first control signal for the first consumer s29 second control signal for the second consumer s30 third control signal for the third consumer

Claims

[1] Vehicle control unit for controlling and supplying power to several consumers (28, 29, 30), comprising a plurality of supply inputs (21, 23) for connection to a respective control unit-external partial power source (12, 14), each of which need not be able to supply the vehicle control unit with power on its own, wherein a current limiting circuit (22, 24) is directly connected downstream of each of the supply inputs (21, 23), wherein the current limiting circuits (22, 24) are configured to limit the current (I1, I2) at a respective supply input (21, 23) to a maximum permissible current (I1 max , I2 max) of the respective control unit-external partial current source (12, 14) connected to the supply input (21, 23), wherein a computing and control unit (26) is provided which determines the current (I1, I2) flowing at a respective supply input and prevents the switching on of one or more predetermined consumers (28, 29, 30) if no current flow can be detected at one of the supply inputs. [2] Control unit according to claim 1, wherein the maximum permissible current (I1) at a supply input (21, 23) max , I2 max ) is not sufficient to simultaneously supply all consumers (28, 29, 30) connected to the control unit. [3] Control unit according to claim 1 or 2, wherein the current limiting circuits (22, 24) are coupled to each other on the output side for the power supply of the consumer(s) (28, 29, 30). [4] Control unit according to claim 3, wherein the interconnected current limiting circuits (22, 24) are connected to the consumer(s) (28, 29, 30) via one or more boost converters (25). [5] Vehicle electrical system, including - a control unit according to one of claims 1 to 4, - at least one further electronic component (10; 10a, 10b), wherein each of the components (10; 10a, 10b) is connected to a terminal (1) of an energy storage device and comprises one or more outputs (11, 13) which can each be operated as a current source, and each output (11, 13) is connected to an associated supply input (21, 23). [6] On-board electrical system according to claim 5, wherein the current available at each output (11, 13) is less than the current required for the intended operation of the control unit (20).

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