Method and brake system for control of brake pressure build-up during a control process

Brake system with electronic braking pressure control which includes wheel sensors for determining the rotational behavior of the individual wheels and an electronic evaluating circuit for evaluating the sensor signals and for generating braking pressure control signals, a master cylinder and wheel brakes which are connected by way of brake lines into which electrically operable braking pressure control valves are inserted, wherein inlet valves are used to control the pressure fluid flow to the wheel brakes and, thus, the pressure increase, and outlet valves are used to control the pressure reduction, comprising:

• means to calculate the wheel deceleration and the vehicle deceleration on the basis of the wheel sensor signals, wherein, the current locking pressure level is calculated from the current wheel and/or vehicle deceleration, and wherein the current wheel braking pressure is calculated from the total time of the outlet valve actuation times of a wheel during a braking pressure reduction period in consideration of the current locking pressure level and the braking pressure reduction characteristic curve of the system, and
• means for calculating the braking pressure rise gradient from the total of the inlet valve actuation times during a braking pressure increase phase in consideration of the wheel cylinder pressure at the commencement of the increase phase and the current locking pressure level.