Method for monitoring the emergency braking capability of an electrohydraulic braking system

The present invention relates to a method for monitoring the function and emergency braking capability of an electro-hydraulic braking system (EHB) comprised of a pedal-operated master cylinder and a pressure source with a hydraulic pump, with an accumulator, and with electrically controllable hydraulic valves, wherein the brake pressure in the wheel brakes is supplied from the pressure source in normal operation, and wherein a switch-over to a hydraulic connection between the master cylinder and the wheel brakes is executed in the event of an emergency braking mode. To monitor the emergency braking capability of an electro-hydraulic braking system (EHBwherein, during normal operation, the brake pressure in the wheel brakes is generated by means of a pressure source comprised of a hydraulic pump, an umulator, and hydraulic valves, and wherein a switch-over to a hydraulic connection between a master cylinder and the wheel brakes is executed in the event of an emergency braking situation. With predetermined events, e.g. during each initialization of the brake system, the emergency braking capability is checked using the following steps:a) charging of the accumulator, without brake pressure buildup in the wheel brakes; measuring the accumulator pressure, or the accumulator volume or the filling level of the accumulator;b) pressure introduction into the wheel brakes until a predetermined pressure threshold is reached, with the hydraulic pump deactivated or hydraulically uncoupled;c) measuring the accumulator pressure;d) determining and evaluating the accumulator performance in response to the pressure introduction into the wheel brakes for finding out the current volume requirement and/or the condition of the brake fluid, detecting air inclusions, etc., and for judging the current emergency braking capability of the brake system.