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CN-116279344-B - Method for operating a brake system of a motor vehicle, control device and motor vehicle

CN116279344BCN 116279344 BCN116279344 BCN 116279344BCN-116279344-B

Abstract

The invention relates to a method for operating a brake system of a motor vehicle, comprising a friction brake system and a recuperation brake system, in which method a cleaning requirement (V1) for a respective wheel brake of the friction brake system of the motor vehicle is determined, a deceleration desired by a driver of the motor vehicle is determined as a function of a brake pedal mechanically decoupled from the friction brake system, and a braking force (V2) required for the desired deceleration of the motor vehicle is determined, wherein a predetermined first part of the braking force is distributed to the recuperation brake system and the remaining part of the required braking force is distributed to the wheel brakes (V3) of the friction brake system, wherein the braking force to be provided by the friction brake system is distributed to the wheel brakes as a function of the determined cleaning requirement for the respective wheel brakes.

Inventors

  • M. Bruch schmahl

Assignees

  • 大众汽车股份公司

Dates

Publication Date
20260508
Application Date
20221221
Priority Date
20211221

Claims (10)

  1. 1. Method for operating a brake system of a motor vehicle, with a friction brake system and a recuperation brake system, in which method a cleaning requirement (V1) of a respective wheel brake of the friction brake system of the motor vehicle is determined, a deceleration desired by a driver of the motor vehicle is determined as a function of a brake pedal position of a brake pedal mechanically decoupled from the friction brake system and a braking force (V2) required for the desired deceleration of the motor vehicle is determined, wherein a preset first part of the braking force is distributed to the recuperation brake system and a remaining part of the required braking force is distributed to the wheel brake (V3) of the friction brake system, wherein the braking force to be provided by the friction brake system is distributed to the wheel brake as a function of the determined cleaning requirement of the respective wheel brake, wherein -Distributing the braking forces distributed to the wheel brakes of the friction brake device to the wheel brakes according to at least one preset stability criterion to be followed, and/or In the event of an intervention of an anti-lock braking system and/or an electronic stability control as a driving dynamics control system into the driving dynamics of the motor vehicle, the distribution of the braking forces between the wheel brakes is preset by the driving dynamics control system, and/or -Selecting the maximum possible recuperation power of the recuperation brake apparatus as a preset first portion of the braking force.
  2. 2. The method according to claim 1, wherein a hydraulic brake pressure to be applied at the respective wheel brake for adjusting the braking force is determined via a stored association rule in accordance with the braking force assigned to the respective wheel brake, and the determined brake pressure is applied at the associated wheel brake.
  3. 3. The method according to claim 1 or 2, wherein the at least one stability criterion is followed when the respective braking forces associated with the wheel brakes correspond at most to a maximum braking force for the respective wheel brakes and/or the braking force ratio between the respective wheel brakes is within an allowable range for the braking force ratio.
  4. 4. Method according to claim 1 or 2, wherein in case the anti-lock system and/or the electronic stability controller intervenes as a driving dynamics control system in the driving dynamics of the motor vehicle, the distribution of the braking force between the recuperation brake device and the friction brake device is preset by the driving dynamics control system.
  5. 5. The method according to claim 1 or 2, wherein the braking force distributed to the wheel brakes is distributed evenly to all wheel brakes when it is determined that there is no cleaning demand.
  6. 6. The method according to claim 1 or 2, wherein, in case the required braking force for the preset deceleration of the motor vehicle is less than or equal to the maximum possible recuperation power of the recuperation brake device and the cleaning demand is determined, a lower recuperation power than the maximum possible recuperation power of the recuperation brake device is selected as the preset first portion of the braking force and the remaining portion of the required braking force is distributed to the friction brake device.
  7. 7. The method according to claim 1 or 2, wherein a greater share of the braking force of the friction brake device is distributed to the wheel brakes of all rear wheels of the motor vehicle than to the wheel brakes of all front wheels.
  8. 8. The method according to claim 1 or 2, wherein the cleaning demand of the respective wheel brake is determined via a model from the brake pressure and the brake frequency applied at the respective wheel brake.
  9. 9. Method according to claim 1 or 2, wherein the higher the respective determined cleaning demand for the wheel brakes, the higher the braking force to be applied at the respective wheel brake by means of the friction brake device is adjusted.
  10. 10. The method of claim 8, wherein the cleaning requirements of the respective wheel brakes are determined via a model from the brake pressure and the brake frequency applied at the respective wheel brakes over their service life.

Description

Method for operating a brake system of a motor vehicle, control device and motor vehicle Technical Field The invention relates to a method for operating a brake system of a motor vehicle. Background A method for controlling a brake system for a vehicle is known from US 2010/0276240 A1. In this method, the master brake cylinder is separated from the wheel brake cylinder by means of a separating valve. The master brake cylinder is configured to detect actuation of the brake input member. The inflow of brake medium from the reservoir to the wheel brake cylinders is controlled by means of a control valve, whereby the brake pressure at the associated wheel is regulated. Disclosure of Invention The object of the present invention is to provide a solution which, with a particularly high energy recovery of the braking energy, enables particularly good cleaning of the respective wheel brakes of the motor vehicle, wherein the brake pedal feel of the driver is particularly little influenced. This object is achieved by a method according to the invention for operating a brake system of a motor vehicle. Further possible embodiments of the invention are disclosed in the description and the figures. The invention relates to a method for operating a brake system of a motor vehicle. The braking system of a motor vehicle comprises a friction braking device and a recuperation braking device. The friction brake device is designed to convert the kinetic energy of the motor vehicle into thermal energy via friction. The friction brake system comprises, for each wheel of the motor vehicle, a wheel brake configured as a respective friction brake. The respective wheel brake may be configured, for example, as a disk brake or a drum brake. The recuperation brake apparatus is designed to convert the movement energy of the motor vehicle into electrical energy. For this purpose, the recuperation brake apparatus can have a generator. The corresponding friction brake is used for deceleration to a significantly lower extent than in vehicles which are decelerated only via friction brake, in particular in vehicles with recuperation brake. This can quickly and often lead to non-optimal friction value ratios at the wheel brakes, especially through signs of corrosion, which can lead to negative effects on braking characteristics, including acoustics of the vehicle. The friction brake should thus be replaced particularly often if necessary. If the recuperation brake fraction is reduced in order to increase the hydraulic brake fraction, this leads to an increase in the consumption of the motor vehicle. In order to overcome these disadvantages, it is provided in the method that the cleaning requirements of the respective wheel brakes of the friction brake system of the motor vehicle are determined. The cleaning requirement may be due, for example, to corrosion of the respective wheel brake. This means that if the wheel brakes have a certain sign of corrosion, the corresponding wheel brakes should be cleaned. In this method, it is furthermore provided that a deceleration of the motor vehicle desired by the driver is determined as a function of a brake pedal position of a brake pedal mechanically decoupled from the friction brake system, and that a braking force required for the desired deceleration of the motor vehicle is determined. The brake pedal position may be determined, for example, by means of a sensor device. Thus, the driver can preset how strongly the motor vehicle should be braked by adjusting the brake pedal. The mechanical decoupling of the brake pedal from the friction brake device is understood to mean that the brake pedal is not directly coupled to the respective wheel brake via hydraulic pressure. This means that no displacement of brake fluid directly by means of the brake pedal takes place in the hydraulic brake circuit connected to the wheel brakes. Instead, a control signal is generated in dependence on the position of the brake pedal, which control signal presets the hydraulic pressure to be applied at the wheel brakes. The hydraulic pressure is regulated by means of an actuator upon receipt of a control signal. A preset first portion of the braking force required for a desired deceleration of the motor vehicle is distributed to the recuperation brake apparatus, and the remaining portion of the required braking force is distributed to the friction brake apparatus. The motor vehicle is thus decelerated not only by the recuperation brake device but also by the friction brake device. In this case, the braking forces provided by the friction brake devices are distributed to the wheel brakes as a function of the determined cleaning requirements of the respective wheel brakes. The friction brake device may, for example, comprise a respective hydraulic brake, wherein a hydraulic brake is associated with each wheel of the motor vehicle. In order to distribute the braking forces to the wheel brakes, the respective braking pressures at