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CN-121989878-A - Method for operating a brake system and motor vehicle

CN121989878ACN 121989878 ACN121989878 ACN 121989878ACN-121989878-A

Abstract

The invention relates to a method for operating a brake system (1) of a motor vehicle (2), wherein the brake system (1) has a front axle brake (3) and a rear axle brake (4) which is designed with improved emissions relative to the front axle brake (3). A setpoint deceleration (SV) of the motor vehicle (2) is determined and a setpoint braking force (SB) for achieving the setpoint deceleration (SV) is determined. According to a predefined deceleration limit Value (VG), a setpoint braking force (SB) is assigned to the front axle brake (3) and the rear axle brake (4) in a targeted manner, such that the greatest possible proportion of the setpoint braking force (SB) is achieved by the rear axle brake (4). The invention further relates to a motor vehicle (2) having a brake system (1) with a front axle brake (3) and a rear axle brake (4) which is designed with improved emissions relative to the front axle brake (3).

Inventors

  • N CRUISE
  • J. Schwalbe
  • J. M. PETERS

Assignees

  • 大众汽车股份公司

Dates

Publication Date
20260508
Application Date
20251103
Priority Date
20241105

Claims (10)

  1. 1. A method for operating a brake system (1) of a motor vehicle (2), wherein the brake system (1) has a front axle brake (3) and a rear axle brake (4), wherein the rear axle brake (4) is configured with improved emissions relative to the front axle brake (3), the method having: Determining a setpoint deceleration (SV) of the motor vehicle (2) by means of a control device (5) of the motor vehicle (2), Determining a theoretical braking force (SB) necessary to obtain the theoretical deceleration (SV) by means of the control device (5), -When the theoretical deceleration (SV) is greater than a predefined deceleration limit Value (VG), the theoretical braking force (SB) is pointedly distributed to the front axle brake (3) and the rear axle brake (4) by the control device (5), and -Realizing all the theoretical braking force (SB) with the rear axle brake (4) when the theoretical deceleration (SV) is equal to or less than the predefined deceleration limit Value (VG).
  2. 2. The method according to claim 1, It is characterized in that the method comprises the steps of, A deceleration of between 0.2g and 0.4g is used as a predefined deceleration limit Value (VG).
  3. 3. The method according to claim 1 or 2, It is characterized in that the method comprises the steps of, The targeted distribution of the setpoint braking force (SB) is carried out in such a way that all wheels (6 a,6 b) of the motor vehicle (2) reach a slip limit simultaneously or that the front wheels (6 a) of the motor vehicle (2) reach a slip limit later than the rear wheels (6 b) of the motor vehicle (2).
  4. 4. The method according to any of the preceding claims, It is characterized in that the method comprises the steps of, The environment of the motor vehicle (2) and/or the state of the motor vehicle (2) is monitored by means of a measuring device (7) of the motor vehicle (2), wherein the deceleration limit (VG) is specifically reduced by the control device (5) as a function of the dangerous situation when the dangerous situation is measured by the measuring device (7).
  5. 5. The method according to claim 4, wherein the method comprises, It is characterized in that the method comprises the steps of, In determining the dangerous situation, other traffic participants and/or lane characteristics and/or objects on the lane and/or weather effects and/or the state of the brake system (1) are taken into account.
  6. 6. The method according to claim 4 or 5, It is characterized in that the method comprises the steps of, Use is made of a measuring device (7) having a vehicle sensor system for detecting the environment of the motor vehicle (2) and/or a receiving device for receiving environmental data of the motor vehicle (2).
  7. 7. The method according to any of the preceding claims, It is characterized in that the method comprises the steps of, The deceleration limit Value (VG) is reduced or increased in a targeted manner by the control device (5) as a function of the characteristic field of the front axle brake (3) and/or the rear axle brake (4).
  8. 8. A motor vehicle (2) having a brake system (1) with a front axle brake (3) for braking a front wheel (6 a) of the motor vehicle (2) and a rear axle brake (4) for braking a rear wheel (6 b) of the motor vehicle (2), It is characterized in that the method comprises the steps of, The rear axle brake (4) is designed with improved emissions relative to the front axle brake (3).
  9. 9. The motor vehicle (2) according to claim 8, It is characterized in that the method comprises the steps of, The rear axle brake (4) has a hard metal coated brake disc and/or a NAO brake lining.
  10. 10. Motor vehicle (2) according to claim 8 or 9, It is characterized in that the method comprises the steps of, The motor vehicle (2) is configured for carrying out the method according to any one of claims 1 to 7.

Description

Method for operating a brake system and motor vehicle Technical Field The invention relates to a method for operating a brake system of a motor vehicle. The invention further relates to a motor vehicle which is designed to carry out the method according to the invention. Background By introducing the european union 7 regulations, the allowable fine dust emissions of motor vehicles are extremely limited compared to the previous legal regulations. For motor vehicles with internal combustion engines, the very demanding highest value of fine dust is determined by the european union 7 regulations with respect to vehicles with electric drive systems. In order to meet the european union 7 regulations, brake systems, for example with hard metal coated brake discs, are currently of great interest. These brake disks have particularly complex tribological properties and particularly low wear compared to conventional brake disks made of gray cast iron or the like. Furthermore, the high CO2 emissions in manufacturing and the complex process flows for producing hard metal coatings, as well as the high manufacturing costs, place a burden on the technology. Furthermore, electromechanical brakes (EMB) are known, wherein the technology is provided in particular for motor vehicles with an electric drive system. Finally, fine-dust optimized brake linings are known, which have, for example, non-asbestos organic (NAO) friction agents and are therefore also referred to as "NAO brake linings". An emission-limiting vehicle state control system is known from DE 10 2021 000 919 B3. In order to reduce non-drive-related emissions (for example fine dust of the wheel brakes, which are emitted by the braking process), the state data are detected and control commands are generated by means of a database module as a function of the emissions to be expected and of the measured emission budget. The known measures and methods for reducing emissions from a brake system of a motor vehicle have the disadvantage that the production of hard metal coatings on brake discs or NAO brake linings is very labor-and cost-intensive. Known operating strategies for low emission operating brake systems have often significant performance-and/or comfort losses. Disclosure of Invention The object of the present invention is therefore to eliminate or at least partially eliminate the aforementioned disadvantages in a method for operating a brake system of a motor vehicle. The object of the invention is, inter alia, to provide a method for operating a brake system of a motor vehicle and a motor vehicle with a brake system, which in a simple and cost-effective manner have reduced fine dust emissions. Furthermore, it is an object of the invention to additionally ensure high driving comfort and high driving safety. The above object is achieved by the present invention. Accordingly, this object is achieved by the method according to the invention for operating a brake system of a motor vehicle and by the motor vehicle according to the invention with a brake system. Further features and details of the invention are found in the dependent claims, the description and the drawings. The features and details described in connection with the method according to the invention are of course also applicable in connection with the motor vehicle according to the invention and vice versa, so that the disclosure concerning the individual inventive aspects is always or can be referred to each other. According to a first aspect of the invention, the object is achieved by a method for operating a brake system of a motor vehicle. The method comprises the following steps: Determining a setpoint deceleration of the motor vehicle by a control device of the motor vehicle, Determining by the control device a theoretical braking force necessary to obtain a theoretical deceleration, -A targeted distribution of the setpoint braking force to the front axle brake and the rear axle brake by the control device when the setpoint deceleration is greater than a predefined deceleration limit value, and -Implementing all theoretical braking forces with the rear axle brake when the theoretical deceleration is less than or equal to the predefined deceleration limit. The method according to the invention is carried out with a motor vehicle having a brake system with a front axle brake and a rear axle brake, wherein the rear axle brake is configured with improved emissions relative to the front axle brake. In other words, the rear axle brake and the front axle brake are differently configured. The rear axle brake differs from the front axle brake at least in that less fine dust is discharged by braking with the rear axle brake than by equivalent braking with the front axle brake at least over the main range of possible braking scenarios of the motor vehicle. The front axle brake and the rear axle brake are preferably configured such that more fine dust is discharged by the front axle brake in full braking pe