Method for operating a brake system of a motor vehicle, and brake system

A brake installation for a motor vehicle comprising:

• a primary brake system comprising:
• a first electrically controllable pressure provision device for providing a brake pressure for actuating hydraulically actuatable wheel brakes,
• a first electronic open-loop and closed-loop control unit, and
• a first pressure detection device, which measures a brake pressure provided by the primary brake system, and
• a secondary brake system comprising:
• a second electrically controllable pressure provision device (4) for providing a brake pressure for actuating at least a part of the hydraulically actuatable wheel brakes,
• a second electronic open-loop and closed-loop control unit, and
• at least one second pressure detection device, the signals of which are processed in the second electronic open-loop and closed-loop control unit,
• wherein the secondary brake system is arranged hydraulically between the primary brake system and the part of the wheel brakes,
• wherein the first electronic open-loop and closed-loop control unit is configured to transmit a signal regarding whether or not a brake pressure control function in the primary brake system is active to the second electronic open-loop and closed-loop control unit,
• wherein the second electronic open-loop and closed-loop control unit is configured to monitor, on the basis of (i) the signals of the second pressure detection device generated based on detected pressure;
• (ii) a predefined brake pressure demand;
• and (iii) the signal regarding whether or not the brake pressure control function in the primary brake system is active, in order to determine a functional capability of the primary brake system to build up a brake pressure corresponding to a predefined brake pressure demand.

A brake installation for a motor vehicle comprising:

• a primary brake system comprising:
• a first electrically controllable pressure provision device for providing a brake pressure for actuating hydraulically actuatable wheel brakes,
• a first electronic open-loop and closed-loop control unit, and
• a first pressure detection device, which measures a brake pressure provided by the primary brake system;
• and
• a secondary brake system comprising:
• a second electrically controllable pressure provision device for providing a brake pressure for actuating at least a part of the hydraulically actuatable wheel brakes),
• a second electronic open-loop and closed-loop control unit, and
• at least one second pressure detection device, the signals of which are processed in the second electronic open-loop and closed-loop control unit,
• wherein the secondary brake system is arranged hydraulically between the primary brake system and the part of the wheel brakes,
• wherein the first electronic open-loop and closed-loop control unit is configured to transmit a signal regarding whether or not a brake pressure control function in the primary brake system is active to the second electronic open-loop and closed-loop control unit,
• wherein the second electronic open-loop and closed-loop control unit is configured to monitor, on the basis of (i) the signals of the second pressure detection device generated based on detected pressure;
• (ii) a predefined brake pressure demand;
• and (iii) the signal regarding whether or not the brake pressure control function in the primary brake system is active, in order to determine a functional capability of the primary brake system to build up a brake pressure corresponding to a predefined brake pressure demand, and
• wherein for the monitoring, the second electronic open-loop and closed-loop control unit compares the signals of the second pressure detection device with the predefined brake pressure demand.