A vehicle brake system and method for increasing the brake pressure in a first wheel brake cylinder and for limiting the brake pressure in a second wheel brake cylinder of a vehicle brake system. The method includes increasing a first brake pressure in the first wheel brake cylinder by controlling/holding a wheel inlet valve in its open state and controlling/holding a first wheel outlet valve in its closed state, and limiting an increase of a second brake pressure in the second wheel brake cylinder during the transfer of brake fluid into the first wheel brake cylinder by controlling/holding a second wheel inlet valve in its closed state and controlling a second wheel outlet valve into its open state. The second wheel outlet valve is controlled with a pulse width-modulated signal so that during the transfer of brake fluid, the second wheel outlet valve is permanently in its open state.

To test a vehicle power braking system, a piston of a power brake pressure generator is displaced twice for a pressure build-up and in between back preferably by a longer distance. Extension of the piston travel during the second displacement is an indication of air in a cylinder of the power brake pressure generator due to an excessively low brake fluid level in a brake fluid reservoir.

A method is described for detecting a leakage during the operation of a braking system. A braking intention signal characterizing a braking intention is generated by actuating a final control system of an actuating circuit; a setpoint braking pressure required in an active circuit is ascertained based on the braking intention signal; an actual braking pressure in the active circuit is set according to the setpoint braking pressure with the aid of a pressure generation unit by moving a displacement piston to actuate a wheel brake coupled to the active circuit; and a pressure modulation is carried out. The pressure modulation includes setting the actual braking pressure in the active circuit to a value greater than the setpoint braking pressure, and lowering the actual braking pressure until the setpoint braking pressure is reached by moving the displacement piston at a predetermined piston speed. Furthermore, a chronological pressure gradient is ascertained, as the actual braking pressure is being lowered, during the pressure modulation, and a leakage of the active circuit is detected based on the ascertained pressure gradient when the pressure gradient is outside a range predetermined for the piston speed.

A method for determining a start time for a recharging procedure for a plunger device of an electronically slip-controllable power brake system, and an electronically slip-controllable power brake system having a plunger device. Plunger devices have a plunger cylinder, a plunger piston, and a plunger working space and are operable by a drive motor. A recharging procedure of the plunger device is required from time to time. The start time for a recharging procedure of the plunger device is ascertained as a function of characteristic values that describe the driving state of a vehicle equipped with the power brake system, and/or the operating state of the plunger device when an actual position of the plunger piston lies within a specifiable working range of the plunger device.

The present disclosure relates to a brake system for a vehicle, having an at least partially automated control function. The brake system comprises a brake pedal to be mechanically actuated by a driver for a brake request and a hydraulic transmission system for conducting a transmission medium which transmits the actuation of the brake pedal by the driver to a wheel brake. For this purpose, the transmission system has an accumulator for the transmission medium in order to temporarily store a displaced volume of the transmission medium upon actuating the brake pedal if the at least partially automated control function is given priority.

A method for boosting a braking force in an electronically slip-controllable vehicle brake system, as well as an electronically slip-controllable vehicle brake system. Vehicle brake systems of this kind are at least equipped with a power brake unit and electronic slip-controllable vehicle brake system. In the case of a malfunction of the power brake unit, the traction-slip control device (92) takes over the boosting. A method for determining a composite signal which is adjusted by controlling a drive of a pressure generator of the slip-controllable vehicle brake system accordingly. To this end, an electronic control unit records two mutually independent input quantities, converts these input quantities into evaluation signals and sums the evaluation signals mathematically to yield a composite signal. The latter represents a setpoint brake pressure that the slip-controllable vehicle brake system supplies by controlling a pressure generator accordingly.

A pump assembly for generating a brake pressure in a hydraulic slip-controlled power vehicle braking system, including a fluid sensor between an electric motor and a piston cylinder unit with the aid of which a small brake fluid quantity inadvertently leaking from the piston cylinder unit in the form of leakage is ascertainable before it affects a function of an electronic control or the electric motor.

Provided are an electronic brake system and a method of controlling the same. The electronic brake system includes a pedal input unit configured to receive a pedal force according to a driver's braking intention, an estimating unit configured to estimate a temperature and a friction coefficient of a brake disk pad, and a control unit configured to correct a braking target pressure according to the driver's braking intention on the basis of the estimated temperature and friction coefficient of the brake disk pad.

A master cylinder and an electronic brake system including the same are disclosed. The master cylinder includes a cylinder body connected to a reservoir and provided with a bore, one end of which is opened in a longitudinal direction, a piston configured to be movable forward and backward within the bore, and at least one master chamber configured to discharge a master chamber in response to a displacement of the piston. The master cylinder includes a pedal simulator provided in the bore. The pedal simulator is spaced apart from the piston by a predetermined distance, is directly pressurized by a brake pedal, and thus provides reaction force. The simulation chamber is formed in the bore, and is separated from the master chamber by the pedal simulator. The simulation passage connects the simulation chamber to the master chamber. The simulation valve is provided in the simulation passage, and controls flow of a pressing medium in response to an opening/closing operation thereof.

A method for operating a motor vehicle brake installation. An electrically controllable pressure modulation device having a pump-valve arrangement is hydraulically arranged between the primary brake system and the front axle brakes. The pump-valve arrangement includes, for each front brake, a first valve, arranged between the inlet valve of the primary brake system and the brake, and an electrically activatable pump, with a suction and pressures ports. The pressure port is connected to the brake. In the presence of a predetermined condition of the primary brake system and of an actuation of the master brake cylinder by the driver, a build-up of brake pressure at the front axle brakes is performed by the pump-valve arrangement. The pressure set by the pump-valve arrangement is higher than the brake pressure in the master brake cylinder, whereas the brake pressure of the master brake cylinder prevails at the brakes of the rear axle.