PRESSURE CONTROL WITH A PUMP
A method for controlling a brake system with a plurality of wheel brakes having associated inlet valves and outlet valves and a hydraulic pump for conveying brake fluid is disclosed. To avoid high pressure peaks, the wheel brake with the highest pressure demand is determined as Maxwheel. To adjust a setpoint pressure, the hydraulic pump conveys volumes of brake fluid. In the remaining wheel brakes, the inlet valve of the wheel brakes is open and the outlet valve of the wheel brakes is closed until the setpoint pressure has been reached. Once the setpoint pressure has been reached, the inlet valve is closedTo adjust the setpoint pressure, the inlet valve of the Maxwheel is open and the outlet valve of the Maxwheel is closed. Once the setpoint pressure has been reached, the inlet valve is kept open and the outlet valve is operated in a pulsed manner.
1 - 11 . (canceled)
12 . A method for controlling a brake system having a plurality of wheel brakes with associated inlet valves and outlet valves, and a hydraulic pump for conveying brake fluid to the plurality of wheel brakes, said method comprising:
determining the wheel brake of the plurality of wheel brakes with the highest pressure demand and assigning the wheel brake with the highest pressure demand as Maxwheel and the other wheel brakes as the remaining wheel brakes;
adjusting a setpoint pressure in the remaining wheel brakes by opening the inlet valve and closing the outlet valve until the setpoint pressure is reached, and closing the inlet valve when the setpoint is reached; and
adjusting a setpoint pressure in the Maxwheel by opening the inlet valve and closing the outlet valve until the setpoint pressure is reached, and keeping open the inlet valve and pulsing the outlet valve when the setpoint is reached.
13 . The method for controlling a brake system as claimed in claim 12 , further comprising keeping open the inlet valve of the Maxwheel when de-energized or partially energized.
14 . The method for controlling a brake system as claimed in claim 13 , further comprising bringing the inlet valve of the Maxwheel into the partially energized open state when two other inlet valves are already closed and a third inlet valve is simultaneously closed.
15 . The method for controlling a brake system as claimed in claim 13 , further comprising selecting the holding current at the inlet valve of the Maxwheel such that the inlet valve is pressed open at a predetermined differential pressure.
16 . The method for controlling a brake system as claimed in claim 12 , wherein during the pressure control, the pressure side of the pump is connected only to the inlet valves of the wheel brakes and to at least one closed separation valve.
17 . The method for controlling a brake system as claimed in claim 12 , further comprising operating the outlet valve in a pulsed manner with a pulse width controller with a predetermined opening ratio, which is set in such a manner that the pressure of the Maxwheel corresponds to the setpoint pressure of the Maxwheel.
18 . The method for controlling a brake system as claimed in claim 12 , further comprising opening the outlet valve while the inlet valve is open to release pressure.
19 . The method for controlling a brake system as claimed in claim 12 , further comprising reducing the speed of the hydraulic pump to release pressure.
20 . The method for controlling a brake system as claimed in claim 12 , further comprising partially energizing the inlet valve to release pressure.
21 . A hydraulic brake system for motor vehicles, comprising:
a plurality of wheel brakes with associated inlet valves and outlet valves;
a hydraulic pump for conveying brake fluid to the plurality of wheel brakes; and a control device configured to
determine the wheel brake of the plurality of wheel brakes with the highest pressure demand and assigning the wheel brake with the highest pressure demand as Maxwheel and the other wheel brakes as the remaining wheel brakes,
adjusting a setpoint pressure in the remaining wheel brakes by opening the inlet valve and closing the outlet valve until the setpoint pressure is reached, and closing the inlet valve when the setpoint is reached, and
adjusting a setpoint pressure in the Maxwheel by opening the inlet valve and closing the outlet valve until the setpoint pressure is reached, and keeping open the inlet valve and pulsing the outlet valve when the setpoint is reached.