Patent ID: 6186601
Filing Date: 2001-02-13
Classification: B60T

Abstract:
A vehicle brake system of a motor vehicle, wherein brake means at its wheels can be subjected to pressure via a master cylinder, with an electronically controllable brake booster, comprisinga vacuum chamber and a pressure chamber which are separated from each other by a movable wall,a control valve arrangement which can be actuated by means of an electromagnetic actuation means and by means of which a pressure difference between the pressure chamber and the vacuum chamber is adjustable, with the movable wall changing its position as a function of the pressure conditions in the vacuum chamber and in the pressure chamber, thereby actuating a master cylinder, withthe electromagnetic actuation means being supplied with current signals by an electronic control unit during operation, which the electronic control unit generates as a function of driving dynamics conditions or external influences, which are sensed by sensors connected with the electric control unit, andupon the presence of certain driving dynamics conditions or external influences, or combinations thereof which render the actuation of the master cylinder necessary with a predetermined probability within a predetermined time interval, the electronic control unit generates control signals for the electromagnetic actuation means, so that the control valve arrangement is actuated to such a degree that at least one of play, backlash, and tolerance-related free travel in at least the brake booster is overcome, characterised in thatno actuation of the brake means takes place,the electronic control unit comprisesa computer for combining the signals sensed by the sensors in accordance with predetermined rules, anda memory for storing the predetermined rules as well as empirical values obtained during the operation of the vehicle brake system, andthe empirical values stored in the memory are combinations of sensed sensor signals as well as of probability values by means of which upon the respective combination of sensed sensor signals being present, a braking operation was carried out within a time interval in the past.