Abstract: A method of determining an initial pressure prevailing between a master brake cylinder and an inlet valve of a wheel brake cylinder of a motor vehicle determines the initial pressure taking into consideration the variation of a voltage of a PWMoperated motor of a pump, which is used for the return delivery of brake fluid from a low-pressure accumulator into the master brake cylinder. Several characteristic quantities of the voltage variation are measured and converted to respective initial pressure values. The characteristic quantities or the initial pressure values determined therefrom are filtered or conditioned in the event of lack in quality or reliability of the measured characteristic quantities. The respective initial pressure values of similar size are averaged, and the averaged initial pressure values are temporally averaged in order to dampen fluctuations.

Abstract: A vacuum brake booster and a method of operation of a vacuum brake booster of a vehicle brake system is disclosed. The vacuum brake booster includes a housing subdivided into at least one vacuum chamber and at least one working chamber. The vacuum chamber is connected to a vacuum source by way of a vacuum port. A sensor unit is associated with the vacuum chamber and is configured for sensing a pressure in the vacuum chamber and supplying a sensed pressure value to an electronic control unit (ECU). The ECU includes an evaluating unit for evaluating the sensed pressure value and calculating the operating point of the vacuum brake booster solely on the basis of the sensed pressure in the vacuum chamber. Plausibilization of the sensed pressure value is performed to monitor the overall system and identify defects of the sensor unit or the vacuum brake booster.

Abstract: A vacuum brake booster and a method of operation of a vacuum brake booster of a vehicle brake system is disclosed. The vacuum brake booster includes a housing subdivided into at least one vacuum chamber and at least one working chamber. The vacuum chamber is connected to a vacuum source by way of a vacuum port. A sensor unit is associated with the vacuum chamber and is configured for sensing a pressure in the vacuum chamber and supplying a sensed pressure value to an electronic control unit (ECU). The ECU includes an evaluating unit for evaluating the sensed pressure value and calculating the operating point of the vacuum brake booster solely on the basis of the sensed pressure in the vacuum chamber. Plausibilisation of the sensed pressure value is performed to monitor the overall system and identify defects of the sensor unit or the vacuum brake booster.

Abstract: Disclosed is an electronic control method for a slip-controlled motor vehicle brake system (1), featuring a distributor device (5) with an electronic unit (7,ECU) and hydraulic unit (6,HCU) having a housing body for hydraulic components, such as electrohydraulic inlet and outlet valves (9,10) for wheel brakes (8) organized in brake circuits, and with a motor-pump-aggregate with an electric motor (15) for redirecting hydraulic fluid from wheel brakes (8) in the direction of a pressure sensor (3). Antilock control is facilitated through the build-up, maintenance and release of pressure in the electrohydraulic inlet and outlet valves (9,10), while the admission pressure input by the driver is analyzed by means of the pressure sensor (3) in the brake system.