Patent ID: 6048039
Filing Date: 2000-04-11
Classification: B60T

Abstract:
A brake system for motor vehicles comprising:an activating unit including a pneumatic brake booster having an outlet side and further including a master cylinder connected to the outlet side of the brake booster;a plurality of wheel brakes connected to the master cylinder,the brake booster includes a control valve that is operable by an electromagnet having an armature for actuating one control valve sealing fitting unit;a brake pressure controller receives a control unit difference value that is calculated by a first adding device between a nominal braking pressure signal based on a distance sensor output and an actual braking pressure signal based on a pressure sensor output and wherein the brake pressure controller outputs a signal corresponding to the position of the armature of the electromagnet;a second adding device receives a signal from a sensor indicating actual armature travel and compares the actual armature travel to a nominal armature travel and generates a standard difference signal for sending to a control valve position control unit;the control valve position control unit influences the position of the control valve by generating an output signal corresponding to a level of electrical current to be supplied to the electromagnet; andwherein the braking pressure control unit includes a parallel circuit of a first control unit that monitors the rapid temporary changes of the signal corresponding to the nominal braking pressure and a second control unit that monitors the slow changes of the signal corresponding to the nominal braking pressure, the first and second control units each output respective signals to a situational switching logic unit that compares the respective signals to predetermined selection criteria and selectively sends one of the respective output signals from the first or the second control unit to the control valve position control unit.