CN113661631A

CN113661631A - Energy supply device for a vehicle control unit

Info

Publication number: CN113661631A
Application number: CN202080026885.6A
Authority: CN
Inventors: R·克施温德-席林; V·西马尔蒂
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2019-04-03
Filing date: 2020-03-19
Publication date: 2021-11-16
Also published as: WO2020200813A1; JP7265648B2; JP2022526003A; DE102019204748A1

Abstract

The invention relates to a power supply device (10) for a vehicle control unit (1), comprising an external power supply unit (3) and an internal energy store (5), wherein the internal energy store (5) can be charged by means of a first voltage converter (7) and a second voltage converter (9), and to a corresponding method for supplying power to a vehicle control unit (1) using such a power supply device (10). In this case, in normal operation, the external energy supply device (3) supplies the control unit (1) with an operating Voltage (VB), wherein in the event of a failure of the external energy supply device (3), the internal energy store (5) supplies the control unit (1) with an energy store Voltage (VER) in the event of a self-sufficient condition, wherein the first voltage converter (7) is connected to the external energy supply device (3) and to the energy store (5) and charges the energy store (5) with a first charging current (IL1), wherein the second voltage converter (9) is connected to the internal energy store (5) and to the external energy supply device (3) and charges the internal energy store (5) with a second charging current (IL2) in the activated state, wherein the switching device (12) monitors the operating Voltage (VB) and the energy store Voltage (VER) and the first output voltage (VUP1) of the first voltage converter (7), and activates or deactivates the second voltage converter (9) in dependence on the present value of the monitored voltage.

Description

Energy supply device for a vehicle control unit

Technical Field

The invention relates to an energy supply device for a vehicle control unit. The invention also relates to a method for supplying a vehicle control unit with such a power supply device.

Background

In vehicles known from the prior art, safety-relevant control units, for example airbag control units, have an internal energy store which is charged when the vehicle is started. Furthermore, there are external energy supply devices, i.e. power supplies which are arranged outside the control unit and which supply the control unit with operating voltage during normal operation. In the event of a failure of the external energy supply device, the internal energy store supplies the control unit with an energy store voltage in the case of self-sufficiency. The energy store is usually implemented as a capacitor and is charged via at least one switching converter. Depending on the size of the capacitor or energy store and the customer's respective requirements for the charging time, a second switching converter is used in addition to the first switching converter in order to charge the capacitor or energy store with a higher charging current. In order to switch on the second switching converter, the output voltage of the first switching converter and the operating voltage of the control unit output by the external energy supply device are evaluated, the second switching converter being activated when the output voltage of the first switching converter falls below a predetermined first threshold value or the operating voltage of the control unit falls below a second threshold value. This may result in that the second switching converter will be switched on when the operating voltage is too low but the output voltage of the first switching converter is stable, although the second switching converter is not needed to charge the energy storage or to maintain its charging voltage. Thus, one of the switching converters may operate in an "unstable" state. Furthermore, interference emissions of the control unit are increased by this connection of the second switching converter.

Disclosure of Invention

The advantage of the energy supply device for a control unit having the features of independent claim 1 is that the additional second switching converter is activated by the switching device only during the start-up phase of the control unit until the internal energy store is charged. In the event of an undervoltage of the operating voltage of the control unit, it is not necessary to forcibly activate the additional second switching converter. The second switching converter is additionally switched to active or activated only when the output voltage of the first switching converter drops. In this way, the two switching converters can be activated only in an operating state of the control unit in which a charging current of the two switching converters is required to charge the energy store or to maintain the charging state of the energy store. This advantageously reduces the on-time of the second switching converter and thus also reduces the interfering emissions of the control unit.

Embodiments of the present invention provide an energy supply device for a vehicle control unit, having an external energy supply device and an internal energy store, which can be charged via a first voltage converter and a second voltage converter. In normal operation, the external energy supply device supplies the control unit with an operating voltage, and in the event of a failure of the external energy supply device, the internal energy store supplies the control unit with an energy store voltage in the event of self-sufficiency. The first voltage converter is connected to the external energy supply device and the energy store and charges the energy store with a first charging current. The second voltage converter is connected to the internal energy store and the external energy supply device and charges the internal energy store with a second charging current in the active state. The switching device monitors the operating voltage and the energy storage voltage and the first output voltage of the first voltage converter and activates or deactivates the second voltage converter in dependence on the current value of the monitored voltage.

Furthermore, a method for supplying a control unit with such a power supply device is proposed. In this case, the control unit is supplied with operating voltage by the external energy supply device during normal operation, and is supplied with energy storage voltage by the internal energy storage device in the event of a fault of the external energy supply device in the self-sufficient case. Furthermore, the energy store is charged by the first voltage converter with a first charging current and by the activated second voltage converter with a second charging current, wherein the operating voltage and the energy store voltage and the first output voltage of the first voltage converter are monitored and the second voltage converter is activated or deactivated depending on the current value of the monitored voltage.

As an operating state, for example, a start-up phase or a normal operating mode or a self-sufficient operating mode of the control unit can be distinguished. The start-up phase is the time period that elapses from the switching on of the control unit to the start of the operation of the control unit. In this context, a normal operating mode can be understood as a control unit operating mode in which the control unit is powered by an external power supply device. In this context, a self-sufficient operating mode may be understood as a control unit operating mode in which the control unit is powered by an internal energy storage.

In this context, a control unit may be understood as a safety-relevant electrical device, for example an airbag control unit, which processes or evaluates the detected sensor signals. For this purpose, the control unit can have at least one evaluation and control unit or arithmetic unit for processing signals or data, at least one memory unit for storing signals or data, at least one interface with the sensor or actuator for reading sensor signals of the sensor or for outputting control signals to the actuator, and/or at least one communication interface for reading or outputting data embedded in a communication protocol. The at least one interface may be constructed based on hardware and/or software. In a hardware-based configuration, the interface may be, for example, a part of a so-called ASIC system that includes various functions of the control unit. It is also possible that the interface is an integrated circuit of its own or is at least partly composed of discrete components. In a software-based configuration, the interface may be, for example, a software module that resides on the microcontroller together with other software modules. The evaluation and control unit or arithmetic unit can be, for example, a signal processor, a microcontroller, etc., wherein the memory unit can be a flash memory, an EEPROM or a magnetic memory unit. The communication interface can be designed to read or output data wirelessly and/or by wire, wherein the communication interface, which can read or output wired data, can read or output data from or into the respective data transmission line, for example electrically or optically. The switching converters may likewise each be part of an ASIC module. The first switching converter can thus be integrated, for example, into an ASIC master module, while the second switching converter can be integrated into an ASIC slave module, which can at least partially take over its function in the event of a malfunction or functional control of the ASIC master module.

Also advantageous is a computer program product with a program code which is stored on a machine-readable carrier, such as a semiconductor memory, a hard disk memory or an optical memory, and which is used for the evaluation, in particular when the evaluation and control unit or arithmetic unit executes the program.

The provision of the energy supply device for a vehicle control unit described in independent claim 1 and the method for supplying a control unit with such an energy supply device described in independent claim 8 can be improved by the measures and refinements listed in the dependent claims.

It is particularly advantageous if the switching device activates the second voltage converter during the start-up phase of the control unit in order to additionally charge the internal energy store with the second charging current when the operating voltage of the external energy supply device is below a predetermined first threshold value and/or the energy store voltage is below a predetermined second threshold value. This allows the energy store of the control unit to be charged more quickly.

In an advantageous embodiment of the energy supply device, during normal operation, the switching device can activate the second voltage converter in order to additionally charge the internal energy store with the second charging current when the first output voltage of the first voltage converter falls below a predetermined third threshold value. The second switching converter is thus advantageously activated only when the second charging current supplied by the second switching converter is actually required to charge the internal energy store or to maintain its charge state, which may be caused by a malfunction or failure of the first switching converter, for example in the event of a drop in the output voltage of the first switching converter.

In a further advantageous embodiment of the energy supply device, the switching device can deactivate the second voltage converter when the internal energy store has reached a predefined charge state. This advantageously prevents one of the two switching converters from operating in an "unstable" state, in which the supplied charging current cannot be absorbed by the internal energy store.

In a further advantageous embodiment of the power supply device, the second voltage converter can be activated automatically as a function of the two monitoring voltages applied by the switching device at the two monitoring inputs of the second voltage converter when the monitoring voltage at the first monitoring input is below a predetermined first holding voltage value and/or the monitoring voltage at the second monitoring input is below a predetermined second holding voltage value. In this case, during a start-up phase of the control unit, the switching device can apply a first monitoring voltage of the operating voltage of the external energy supply device to the first monitoring input of the second voltage converter and a second monitoring voltage of the energy store to the second monitoring input of the second voltage converter. Furthermore, during normal operation of the control unit, the switching device can apply a stepped-down third monitoring voltage of the first output voltage of the first voltage converter to the first monitoring input of the second voltage converter and a third monitoring voltage of the first output voltage of the first voltage converter to the second monitoring input of the second voltage converter. Thereby, the switching device can be constructed in a simple manner. Furthermore, the automatic activation built into the known ASIC slave can be used continuously via the two monitoring inputs. Existing systems can thus also be easily retrofitted.

In an advantageous embodiment of the method, during a start-up phase of the control unit, the second voltage converter can be activated together with the first voltage converter in order to additionally charge the internal energy store with the second charging current when the operating voltage of the external energy supply device falls below a first preset threshold value and/or the energy store voltage of the energy store falls below a second preset threshold value. Furthermore, during normal operation, the second voltage converter can be activated in order to additionally charge the internal energy store with a second charging current when the first output voltage of the first voltage converter is below a predetermined third threshold value. In this case, during the start-up phase and/or during normal operation, the second voltage converter can be deactivated again when the internal energy store has reached the predefined charge state.

Drawings

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. In the drawings, the same reference numerals denote parts or elements performing the same or similar functions.

Fig. 1 shows a schematic representation of an exemplary embodiment of a power supply device for a vehicle control unit according to the invention.

Fig. 2 shows a schematic flow diagram of an exemplary embodiment of a method according to the present disclosure for supplying a control unit with the energy supply device from fig. 1.

Detailed Description

As can be seen from fig. 1, the shown embodiment of the energy supply device 10 for the control unit 1 according to the invention comprises an external energy supply device 3 and an internal energy storage 5. The internal energy store 5 can be charged via the first voltage converter 7 and via the second voltage converter 9. In normal operation, the external energy supply device 3 supplies the control unit 1 with an operating voltage VB. In the event of a failure of the external energy supply device 3, the internal energy store 5 supplies the control unit 1 with the energy store voltage VER in the case of self-sufficiency. As can also be seen from fig. 1, the first voltage converter 7 is connected to the external energy supply device 3 and to the energy store 5 and charges the energy store 5 with a first charging current IL 1. The second voltage converter 9 is likewise connected to the internal energy store 5 and the external energy supply device 3 and, in the activated state, charges the internal energy store 5 with a second charging current IL 2. The switching device 12 monitors the operating voltage VB and the energy store voltage VER as well as the first output voltage VUP1 of the first voltage converter 7 and activates or deactivates the second voltage converter 9 depending on the current value of the monitored voltage.

In the exemplary embodiment shown, during the start-up phase, switching device 12 activates second voltage converter 9, which outputs second output voltage VUP2, in order to additionally charge internal energy store 5 with second charging current IL2, when operating voltage VB of external energy supply device 3 falls below a first preset threshold value and/or energy store voltage VER of internal energy store 5 falls below a second preset threshold value. Furthermore, during normal operation, when the first output voltage VUP1 of the first voltage converter 7 is below a preset third threshold value, the switching device 12 activates the second voltage converter 9 in order to charge the internal energy store 5 with the second charging current IL 2. Furthermore, the switching device 12 deactivates the second voltage converter 9 when the internal energy store 5 has reached a predetermined charge state. In the embodiment shown, the internal energy store 5 is implemented as a capacitor.

As can also be seen from fig. 1, the switching device 12 and the first switching converter 7 each receive a first monitoring voltage VB M which is representative of the operating voltage VB of the external energy supply device 3. The first switching converter 7 receives a first monitoring voltage VB M at a monitoring input terminal 1M 1. Furthermore, switching device 12 receives a second monitoring voltage VER _ M, which represents the energy store voltage VER of internal energy store 5, and a third monitoring voltage VUP1_ M, which represents first output voltage VUP1 of first voltage converter 7. The nominal value of the operating voltage is approximately 13.5 volts and the nominal value of the energy store voltage VER and the nominal value of the first output voltage VUP1 of the first switching converter 7 are approximately 33 volts in each case.

In the embodiment shown, the second voltage converter 9 is automatically activatable as a function of the two monitoring voltages applied by the switching means 12 at the two monitoring inputs 2M1, 2M2 of the second voltage converter 9. In this case, the second voltage converter 9 will automatically activate and output an additional second charging current IL2 if the monitored voltage at the first monitoring input 2M1 falls below a predetermined first holding voltage value and/or the monitored voltage at the second monitoring input 2M2 falls below a predetermined second holding voltage value. Here, the first holding voltage value is approximately 10 volts, and the second holding voltage value is approximately 32 volts.

In an alternative embodiment, not shown, the switching means 12 activate and deactivate the second voltage converter 9 in dependence on the current value of the monitored voltage using a control signal which is applied to at least one corresponding control input of the second voltage converter 9 via at least one control line.

In the exemplary embodiment shown, during a start-up phase of control unit 1, switching device 12 applies a first monitoring voltage VB _ M of operating voltage VB of external energy supply device 3, which is rated at approximately 13.5 volts, to first monitoring input 2M1 of second voltage converter 9 and applies a second monitoring voltage VER _ M of energy store voltage VER, which is rated at approximately 33 volts, of internal energy store 5 to second monitoring input 2M1 of second voltage converter 9. Since the voltage of the energy store 5 rises slowly during the start-up phase of the control unit 1, the second voltage converter 9 is activated until the internal energy store 5 reaches a predefined charge state or nominal charge voltage. Since the operating voltage VB of the external energy supply device 3 is generally higher than the first holding voltage value of approximately 10 volts, the second voltage converter 9 is deactivated when the internal energy store 5 reaches its predefined charge state and exceeds the second holding voltage value of approximately 32 volts, so that only the first charging current IL1 is applied to the internal energy store 5. In addition, during subsequent normal operation of the control unit 1, the switching device 12 applies the stepped-down third monitoring voltage VUPl _ M/n of the first output voltage VUP1 of the first voltage converter 7 to the first monitoring input 2M1 of the second voltage converter 9 and the third monitoring voltage VUP1_ M of the first output voltage VUP1 of the first voltage converter 7 to the second monitoring input 2M2 of the second voltage converter 9. In this case, the third monitoring voltage VUP1_ M of the first output voltage VUP1 of the first voltage converter 7 has a nominal value of approximately 33 volts. The stepped-down third monitoring voltage VUP1_ M/n of the first output voltage VUP1 of the first voltage converter 7 has a nominal value of approximately 11 volts. Therefore, in the illustrated embodiment, the value of the denominator "n" of the switching device 12 for stepping down the third monitor voltage VUP1_ M of the first output voltage VUP1 of the first voltage converter 7 is 3. This means that in the transition between the start phase and normal operation, the switching device 12 switches the monitoring voltage applied to the two monitoring inputs 2M1, 2M 2. If the first output voltage VUP1 of the first voltage converter 7 drops during normal operation of the control unit 1, for example due to a malfunction, so that one of the two holding voltage values is below approximately 10 volts or 32 volts, the second voltage converter 9 is activated again and the internal energy store 5 is additionally supplied with the second charging current IL 2. If the first output voltage VUP1 of the first voltage converter 7 again exceeds the holding voltage value, the second voltage converter 9 is deactivated again. In order to avoid frequent switching between the active and the inactive state of the second voltage converter 9, the holding voltage value has a hysteresis between the active point and the inactive point. This means that the second voltage converter 9 is activated when the first output voltage VUP1 of the first voltage converter 7 falls below the activation point and is deactivated again when the first output voltage VUP1 of the first voltage converter 7 rises above the deactivation point.

As can also be seen from fig. 2, in the exemplary embodiment of the method 100 according to the disclosure for supplying the control unit 1 with the energy supply device 10 shown in fig. 1, in step S100 the control unit 1 is switched on and the operating voltage VB of the external energy supply device 3 and the energy storage voltage VER of the internal energy storage 5 are monitored. In step S110, the first switching converter 7 and the second switching converter 9 are activated in order to charge the energy store 5 with the first charging current IL1 by the first voltage converter 7 and with the second charging current IL2 by the second voltage converter 9 during the start-up phase. In step S120, it is checked whether the internal energy store 5 has reached its nominal charging state. If it is determined in step S120 that the internal energy store 5 has not reached the nominal state of charge, the method will continue to repeat step S110. If it is determined in step S120 that the internal energy store 5 has reached the nominal charging state, the second voltage converter 9 is deactivated in step S130 and the first output voltage VUP1 of the first voltage converter 7 is monitored in step S140. In step S150, it is checked whether the first output voltage VUP1 of the first voltage converter 7 is below a predetermined threshold value. If it is determined in step S150 that the first output voltage VUP1 of the first voltage converter 7 has not fallen below the preset threshold value, the method will continue to repeat step S140 and monitor the first output voltage VUP1 of the first voltage converter 7. If in step S150 it is determined that the first output voltage VUP1 of the first voltage converter 7 falls below the preset threshold value, the method will continue to repeat step S110 and additionally activate the second voltage converter 9.

Thus, in the exemplary embodiment shown, during the start-up phase of control unit 1, the second voltage converter is activated together with first voltage converter 7 in order to additionally charge internal energy store 5 with second charging current IL 2. Furthermore, during normal operation, when the first output voltage VUP1 of the first voltage converter 7 falls below a predetermined threshold value, the second voltage converter 9 is activated in order to additionally charge the internal energy store 5 with the second charging current IL 2. When the internal energy store 5 has reached the predetermined charge state, the second voltage converter 9 is deactivated again.

The method can be implemented in the control unit 1, for example, in software or hardware or a mixture of software and hardware.

Claims

1. Energy supply device (10) for a control unit (1) of a vehicle, having an external energy supply device (3) and an internal energy store (5), which can be charged via a first voltage converter (7) and via a second voltage converter (9), wherein in normal operation the external energy supply device (3) supplies an operating Voltage (VB) to the control unit (1), wherein in the event of a failure of the external energy supply device (3), the internal energy store (5) supplies the control unit (1) with an energy store Voltage (VER) in the event of self-sufficiency, wherein the first voltage converter (7) is connected with the external energy supply device (3) and the energy store (5) and charges the energy store (5) with a first charging current (IL1), wherein the second voltage converter (9) is connected with the internal energy store (5) and the external energy supply device (3) and charges the energy store (5) In an active state, the internal energy store (5) is charged with a second charging current (IL2), wherein a switching device (12) monitors the operating Voltage (VB) and the energy store Voltage (VER) and a first output voltage (VUP1) of the first voltage converter (7) and activates or deactivates the second voltage converter (9) as a function of the current value of the monitored voltage.

2. Energy supply device (10) according to claim 1, characterized in that the switching device (12) activates the second voltage converter (9) during a start-up phase of the control unit (1) in order to additionally charge the internal energy storage (5) with the second charging current (IL2) when an operating Voltage (VB) of the external energy supply apparatus (3) is below a preset first threshold value and/or the energy storage Voltage (VER) is below a preset second threshold value.

3. Energy supply device (10) according to claim 1 or 2, characterized in that the switching device (12) activates the second voltage converter (9) during the normal operation in order to additionally charge the internal energy storage (5) with the second charging current (IL2) when the first output voltage (VUP1) of the first voltage converter (7) is below a preset third threshold value.

4. Energy supply device (10) according to claim 2 or 3, characterized in that the switching device (12) deactivates the second voltage converter (9) when the internal energy storage (5) has reached a preset charge state.

5. Energy supply device (10) according to one of claims 1 to 4, characterized in that the second voltage converter (9) can be automatically activated depending on the two monitoring voltages applied by the switching device (12) at the two monitoring inputs (2M1, 2M2) of the second voltage converter (9) when the monitoring voltage at the first monitoring input (2M1) is below a preset first holding voltage value and/or the monitoring voltage at the second monitoring input (2M2) is below a preset second holding voltage value.

6. Energy supply device (10) according to claim 5, characterized in that during a start-up phase of the control unit (1), the switching device (12) applies a first monitoring voltage (VB _ M) of the operating Voltage (VB) of the external energy supply apparatus (3) to a first monitoring input (2M1) of the second voltage converter (9) and the switching device applies a second monitoring voltage (VER _ M) of the energy storage Voltage (VER) of the energy storage (5) to the second monitoring input (2M1) of the second voltage converter (9).

7. Energy supply device (10) according to claim 6, characterized in that during normal operation of the control unit (1), the switching device (12) applies a stepped-down third monitoring voltage (VUP1_ M/n) of the first output voltage (VUP1) of the first voltage converter (7) to the first monitoring input (2M1) of the second voltage converter (9) and the third monitoring voltage (VUP1_ M) of the first output voltage (VUP1) of the first voltage converter (7) (VB) to the second monitoring input (2M2) of the second voltage converter (9).

8. Method (100) for supplying a control unit (1) of a vehicle with a power supply device (10) according to one of claims 1 to 7, wherein in normal operation an operating Voltage (VB) is supplied by the external power supply device (3) to the control unit (1) and in the event of a failure of the external power supply device (3) an energy storage Voltage (VER) is supplied by the internal energy storage (5) to the control unit (1) in the event of self-sufficiency, wherein the energy storage (5) is charged by the first voltage converter (7) with a first charging current (IL1) and the energy storage (5) is charged by the activated second voltage converter (9) with a second charging current (IL2), wherein the operating Voltage (VB) and the energy storage Voltage (VER) and a first output voltage (P1) of the first voltage converter (7) are monitored, and activating or deactivating the second voltage converter (9) in dependence on the current value of the monitored voltage.

9. Method (100) according to claim 8, characterized in that the second voltage converter (9) is activated together with the first voltage converter (7) during a start-up phase of the control unit (1) in order to additionally charge the internal energy storage (5) with the second charging current (IL2) when the operating Voltage (VB) of the external energy supply device (3) is below a preset first threshold value and/or the storage Voltage (VER) of the energy storage (5) is below a preset second threshold value.

10. The method (100) according to claim 9, wherein the second voltage converter (9) is activated during the normal operation when the first output voltage (VUP1) of the first voltage converter (7) is below a preset third threshold value in order to additionally charge the internal energy storage (5) with the second charging current (IL 2).

11. The method (100) according to claim 9 or 10, wherein the second voltage converter (9) is deactivated again when the internal energy storage (5) has reached a preset state of charge.