Patent ID: 7267412

Claim:
Method for calibrating a brake control characteristic of a vacuum brake booster of a vehicle brake system, comprising: storing an initial brake control characteristic; determining a pressure or pressure difference of the vacuum brake booster; and modifying the stored brake control characteristic based on the determined pressure or pressure difference, wherein the brake control characteristic is modified by extrapolation of measured values and a currently measured value is taken into consideration when the following conditions are satisfied: a) a gradient of the hydraulic pressure is lower than 60 bar/sec; b) the gradient of the hydraulic pressure exceeds zero; c) the gradient of the hydraulic pressure currently is lower than the gradient of hydraulic pressure when the current brake control characteristic was determined; d) there is no active braking intervention of an electronic brake control; e) a vacuum in a vacuum chamber of the vacuum brake booster is lower than 100 millibar; f) a difference between a currently determined pressure difference of the vacuum brake booster and a previously determined pressure difference of the vacuum brake booster is lower than ±50 millibar; and g) a difference between the currently measured value and a previous or predefined measured value is greater than or equal to 1.0 bar.