Multiple-circuit, hydraulically open brake system, in particular for a highly automated or autonomous vehicle

A method for operating a multiple-circuit, hydraulically open brake system in a vehicle, the method comprising:

• in normal operation:
• operating a main system to increase, reduce, or maintain pressure in a plurality of brake circuits via a first single-circuit pressure generator;
• performing individual brake pressure modulation in at least two wheel brakes with a modulation unit;
• controlling a first shut-off valve and a second shut-off valve of the main system with a first evaluation and control unit of the main system;
• controlling a third shut-off valve and a fourth shut-off valve of a secondary system with the first evaluation and control unit;
• and
• when the main system fails:
• operating a second evaluation and control unit of the secondary system to increase, reduce, or maintain the pressure in the plurality of brake circuits via a second single-circuit pressure generator;
• and
• omitting the individual brake pressure modulation in the at least two wheel brakes,
• operating the brake system, in normal operation and when the main system fails, to generate braking pressure for stopping the vehicle without mechanical and/or hydraulic intervention from a driver of the vehicle,
• wherein the brake system includes (i) the at least two wheel brakes, which are each assigned to a respective brake circuit of the plurality of brake circuits, each brake circuit having a pressure-relief path, (ii) the first single-circuit pressure generator, (iii) the second single-circuit pressure generator, the first and second single-circuit pressure generators hydraulically connected in parallel between at least one fluid container and the at least two wheel brakes;
• and (iv) the modulation unit modulating respective hydraulic connections between the first and second single-circuit pressure generators to the at least two wheel brakes and for the individual brake pressure modulation in the at least two wheel brakes,
• wherein the first single-circuit pressure generator is assigned to the main system which has a first energy supply, the first evaluation and control unit, the first shut-off valve, and the second shut-off valve,
• wherein the first shut-off valve connects the first single-circuit pressure generator to at least one first wheel brake of the at least two wheel brakes assigned to a first respective brake circuit,
• wherein the second shut-off valve connects the first single-circuit pressure generator to at least one second wheel brake of a second respective brake circuit,
• wherein the second single-circuit pressure generator is assigned to the secondary system, which has a second energy supply which is independent of the first energy supply, the second evaluation and control unit, the third shut-off valve, and the fourth shut-off valve,
• wherein the third shut-off valve connects the second single-circuit pressure generator to the at least one first wheel brake of the first brake circuit,
• wherein the fourth shut-off valve connects the second single-circuit pressure generator to the at least one second wheel brake of the second brake circuit,
• wherein the second evaluation and control unit controls the second single-circuit pressure generator,
• wherein components of the modulation unit are assigned to the main system so that the components of the modulation unit and the first single-circuit pressure generator are controlled by the first evaluation and control unit and supplied with energy by the first energy supply.