Electronically controllable brake booster

The present invention relates to an electronically controllable brake booster. The invention relates in particular to an electronically controllable brake booster with a vacuum chamber and a pressure chamber, which are separated from one another by a moveable wall. A control valve arrangement can be actuated by means of an electromagnetic actuating device. A pressure difference between the pressure and the vacuum chamber can be set via the control valve arrangement. The control valve arrangement takes up a holding position, a pressure buildup position or a pressure reduction position in accordance with a current generated as correcting variable by an electronic control unit and flowing through the electromagnetic actuating device. A cylinder-piston arrangement is connected to the brake booster, this arrangement comprising a piston, coupled to a brake pedal, of a hydraulic cylinder which has a hydraulic connection leading to a wheel brake. A sensor arrangement serves to detect a signal which is correlated with the pressure of the hydraulic cylinder and which reproduces the controlled variable. A brake booster of this kind is described, for example, in DE 19527 493 A1, which is incorporated by reference herein, together with a learning process for the operating point setting. Electronically controllable brake booster with a vacuum chamber and a pressure chamber, which are separated from one another by a moveable wall, a control valve arrangement, which can be actuated by means of an electromagnetic actuating device and via which a pressure difference between the pressure and the vacuum chamber can be set, wherein the control valve arrangement takes up a holding position, a pressure build-up position, a pressure reduction position in accordance with a current generated as correcting variable by an electronic control unit and flowing through the electromagnetic actuating device, a cylinder-piston arrangement, which is connected to the brake booster and comprises a piston, coupled to a brake pedal, of a hydraulic cylinder which has a hydraulic connection leading to a wheel brake, a sensor arrangement for detecting a signal which is correlated with the pressure of the hydraulic cylinder and which reproduces the controlled variable, wherein the electronic control unit establishes a command variable, taking account of the output signal of a sensor arrangement detecting the driver's braking requirement, and wherein the value of the correcting variable remains uncha