Method for functional testing of a pressure generator assembly of an electronically slip-controllable external power braking system having redundant brake pressure generation, in particular for an autonomously drivable motor vehicle

A method for functionally testing a secondary pressure generator assembly in an electronically slip-controllable power brake system having redundant brake pressure generation, the power brake system including:

• a primary pressure generator assembly to which a first electronic control device is assigned and that includes primary components, the primary components including a first motor controllable by the first electronic control device, and a first pressure generator drivable by the first motor, and the secondary pressure generator assembly to which a second electronic control device is assigned and that includes secondary components, the secondary components including a second motor controllable by the second electronic control device and a second pressure generator drivable by the second motor, the primary pressure generator assembly and the secondary pressure generator assembly being capable of being contacted, parallel to one another and each in controllable fashion, to at least one brake circuit, the power brake system further including at least one wheel brake capable of being loaded by pressure medium being separably connected to the brake circuit, an electronically actuatable first valve device configured to control a contacting of the first pressure generator to the brake circuit, an electronically actuatable second valve device configured to control a contacting of the second pressure generator to the brake circuit, and an electronically actuatable third valve device configured to control a contacting of the wheel brake to the brake circuit, wherein the power brake system is configured to perform a braking by applying to the wheel brake a braking pressure generated by the primary pressure generator assembly, without use of the secondary pressure generator assembly, when the primary pressure generator assembly is in a primary pressure generator assembly faultless state and is configured to perform the braking by applying to the wheel brake a braking pressure generated by the secondary pressure generator assembly when the primary pressure generator assembly is in a primary pressure generator assembly fault state, the method comprising the following steps:
• actuating the first valve device and the second valve device in such a way that the first pressure generator and the second pressure generator are hydraulically contacted, parallel to one another, to the brake circuit, such that the primary pressure generator assembly and the secondary pressure generator assembly are hydraulically connected to each other via at least one hydraulic line of the brake circuit;
• actuating the third valve device in such a way that the wheel brake is decoupled from the brake circuit;
• and
• while both (a) all of the at least one wheel brake is decoupled from the brake circuit due to the actuating of the third valve device and (b) the primary pressure generator assembly and the secondary pressure generator assembly are hydraulically connected to each other via the at least one hydraulic line of the brake circuit due to the actuating of the first valve device and the second valve device:
• using the second electronic control device to set the secondary pressure generator assembly into a predefined testing configuration;
• actuating the first pressure generator, the first motor to generate in the brake circuit a pressure corresponding to a target value of an operation of one of the components of the primary pressure generator assembly or of an operation of one of the components of the secondary pressure generator assembly while the secondary pressure generator assembly is set in the testing configuration;
• measuring an actual value of the operation of the one of the components of the primary pressure generator assembly or of the operation of the one of the components of the secondary pressure generator assembly;
• comparing the measured actual value to the target value;
• and
• determining whether the secondary pressure generator assembly is in a secondary pressure generator assembly fault state based in a result of the comparison.