Method for adjusting brake pressures, brake system of a motor vehicle for carrying out such method, and motor vehicle comprising such a brake system

An electronic brake system of a motor vehicle, the electronic brake system comprising:

• one wheel brake and one speed sensor per wheel;
• an electronic brake control unit configured to:
• determine respective brake pressures acting on wheel brakes by controlling a pressure distribution ratio of brake pressures acting on wheel brakes of a front axle of the motor vehicle to brake pressures acting on wheel brakes of a rear axle of the motor vehicle,
• receive driver brake requests determined by a driver of the motor vehicle and/or external brake requests,
• receive and evaluate speed measurements of the speed sensors of the wheels,
• control an ideal pressure distribution ratio of brake pressure at the front axle to brake pressure at a rear axle while taking into account the speed measurements, and
• determine an initial pressure distribution ratio value by:
• recording a first speed measurement of the front axle and a second speed measurement of the rear axle,
• recording, at a same time of measurement, a velocity of the motor vehicle as a reference value,
• linking each of the speed measurement of the front axle and the speed measurement of the rear axle with the reference value in a manner that represents a wheel slip on the respective axle, and a first slip value relating to the front axle and a second slip value relating to the rear axle, which are generated in this way, are set in relation to each other, and
• linking a distribution index thereby determined with a predetermined pressure distribution ratio;
• and
• a memory configured to store the initial pressure distribution ratio value for controlling the ideal pressure distribution ratio.

A method for operating an electronic brake system for motor vehicles, the method comprising:

• determining, by a brake control unit, respective brake pressures acting on wheel brakes by controlling a pressure distribution ratio of brake pressures acting on wheel brakes of a front axle to brake pressures acting on wheel brakes of a rear axle of the motor vehicle;
• receiving, by the brake control unit, driver brake requests determined by a driver of the motor vehicle and/or external brake requests;
• determining, by the brake control unit, appropriate brake pressures,
• wherein the brake control unit takes into consideration an initial pressure distribution ratio value, which is ascertained in a driver braking mode or in a pressure control mode and is stored and kept available for later consideration,
• wherein the initial pressure distribution ratio value is determined:
• by recording, a first speed measurement of the front axle and a second speed measurement of the rear axle, and
• by recording, at the same time of measurement, an acceleration of the motor vehicle as a reference value,
• by linking each of the speed measurement of the front axle and the speed measurement of the rear axle with the reference value in a manner that represents a wheel slip on the respective axle, and a first slip value relating to the front axle and a second slip value relating to the rear axle, which are generated in this way, are set in relation to each other, and
• by linking a distribution index thereby determined with a predetermined pressure distribution ratio.