Airbag control unit, power network, and method for controlling a voltage network in a motor vehicle

A voltage network in a motor vehicle, the voltage network comprising:

• at least one contactor;
• a high-voltage power system having at least one high-voltage battery disconnectable from the high-voltage power system via at least one contactor;
• and
• a low-voltage on-board power system with an on-board power system battery;
• an airbag control device;
• and
• a high-voltage control device that actuates the at least one contactor at least as a function of an actuation signal of the airbag control device,
• wherein the high-voltage control device includes a non-volatile memory that stores an actuation signal of the airbag control device as a stored signal,
• wherein, when powering up occurs, the at least one contactor is closed only if there is no current entry of the stored signal present in the non-volatile memory,
• wherein the airbag control device generates at least one actuation signal for an actuation time period as a function of at least one sensor signal, the airbag control device comprises at least one non-volatile memory in which the generated at least one actuation signal is stored,
• wherein, in the event of failure of a voltage supply, the airbag control device maintains the at least one actuation signal for a holding time period,
• wherein, when the at least one actuation signal is generated, a status signal is stored in the at least one non-volatile memory or in a further non-volatile memory, which status signal is deleted if the at least one actuation signal was generated for longer than a storage time period that is longer than the holding time period and less than or equal to the actuation time period,
• wherein, when the airbag control device is powered up, an actuation signal is transmitted for a second actuation time period if the status signal is still set.

A method for actuating a voltage network in a motor vehicle, wherein the voltage network has a high-voltage power system with a high-voltage battery which is disconnectable from the high-voltage power system via at least one contactor, and a low-voltage on-board power system with an on-board power system battery, an airbag control device and a high-voltage control device,

• wherein the high-voltage control device actuates the at least one contactor at least as a function of an actuation signal of the airbag control device,
• wherein the high-voltage control device and the airbag control device are each embodied with at least one non-volatile memory in which the occurrence of an actuation signal of the airbag control device is stored,
• wherein, when the high-voltage control device is powered up the at least one contactor is closed only if there is no current entry of an actuation signal present as a signal in the non-volatile memory of the high-voltage control device,
• wherein, when a voltage supply is present, the airbag control device makes available the actuation signal for an actuation time period, and when the voltage supply fails, the airbag control device keeps the actuation signal available for at least a holding time period,
• wherein, when the at least one actuation signal is generated, the airbag control device stores a status signal in the at least one non-volatile memory of the airbag control device or in a further non-volatile memory of the airbag control device,
• wherein the status signal is deleted if the at least one actuation signal is generated for longer than a storage time period,
• wherein the storage time period is longer than the holding time period and less than or equal to the actuation time period,
• wherein, when the airbag control device is powered up, an actuation signal is transmitted again for a second actuation time period if the status signal is still set or if the generated at least one actuation signal is stored in the at least one non-volatile memory.