Brake system for motor vehicles

Patent metadata

Field	Value
Publication number	US-9663082-B2
Application number	US-201414911845-A
Country	US
Kind code	B2
Filing date	Aug 1, 2014
Priority date	Aug 14, 2013
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A brake system for motor vehicles, with a brake pedal for operating a master brake cylinder with a piston and pressure chamber connected to a wheel brake, a displacement sensor that detects the brake pedal displacement, a pedal force detection device that detects the brake pedal force, a brake pressure modulation unit applying pressure to the wheel brakes and regulating the wheel brakes individually. A cylinder-piston device for hydraulically producing a force that acts on the master cylinder piston in addition to the pedal force. A pressure supply device to supply pressure medium into the cylinder-piston arrangement. A hydraulic device supplying pressure medium into the brake circuit. A cylinder-piston arrangement upstream of the master brake cylinder generates a force acting on the master cylinder piston. An electronic control and regulation unit, executes an algorithm for the regulation of the brake system pressure.

First claim

The invention claimed is:

1. A brake system for motor vehicles, comprising a brake pedal for operating a master brake cylinder with at least one hydraulic piston, at least one pressure chamber and at least one connected brake circuit that is placed under a brake system pressure of a pressure medium when the brake pedal is operated and the at least one connected brake circuit is connected to at least one hydraulically activated wheel brake that are associated with wheels of the motor vehicle,
a displacement detection device, which detects an operating displacement of the brake pedal or of a component connected to the brake pedal,
a pedal force detection device, which detects a force exerted on the brake pedal acting on the master brake cylinder,
a brake pressure modulation unit that passes the brake system pressure to the wheel brakes or to regulate a brake pressure applied to the wheel brakes individually,
an electrically controllable pressure supply device for supplying the pressure medium to the brake system,
a cylinder-piston arrangement connected upstream of the master brake cylinder for the hydraulic generation of a force acting on the master cylinder piston in an operation direction in addition to the force exerted on the brake pedal,
an electronic control and regulation unit, operated using a method for the regulation of the brake system pressure,
at least one pressure sensor for detecting the brake system pressure, and
the electronic control and regulation unit configured to activate the pressure supply device to produce a defined brake pedal state that has been determined by the electronic control and regulation unit wherein the state that is defined by the brake pedal travel and the brake pedal force is converted into a target state by a control method that minimizes a quality criterion related to a difference between the brake pedal travel and the brake pedal force and the target state.

2. The brake system as claimed in claim 1 , further comprising in that the electronic control and regulation unit uses the displacement of the brake pedal state from a predetermined brake pedal characteristic as the quality criterion.

3. The brake system as claimed in claim 2 , further comprising in that the brake pedal characteristic is described by a mathematical function of a dependency of the brake pedal force on the brake pedal travel or an inverse function thereof, which represents the dependency of the brake pedal travel on the brake pedal force.

4. The brake system as claimed in claim 1 further comprising in that the control method consists of associating a point lying on the brake pedal characteristic that is at a shortest distance from a previous brake pedal state with a previous brake pedal state as the target state.

5. The brake system as claimed in claim 2 further comprising in that the quality criterion is calculated according to the formulas;
δ≈((λ s δ s ) −2 +(λ F δ F ) −2 ) −1/2

with the travel deviation
δ s =s Ped −S soll [F Ped ]

and the force deviation
δ F =F Ped −F soll [s Ped ],

wherein λ s and λ F are scaling factors,
δ is a distance, and
wherein S soll [F Ped ] and F soll [S Ped ] are functional representations of the predetermined characteristic.

6. The brake system as claimed in claim 2 further comprising in that the predetermined brake pedal characteristic is stored in the electronic control and regulation unit in the form of a numerical table.

7. The brake system as claimed in claim 1 further comprising in that the supply of the pressure medium into the brake circuit is carried out by a separating piston device.

8. The brake system as claimed in claim 1 further comprising in that the supply of the pressure medium into the brake circuits of a dual circuit brake system is carried out by a separating piston device associated with each of the brake circuits.

9. The brake system as claimed in claim 1 further comprising in that the electronic control and regulation unit determines the brake pedal force from detected the brake system pressure values and a pressure value provided by the pressure supply device.

10. The brake system as claimed in claim 9 , further comprising in that the brake pedal force is calculated according to the following formula:
F=A THZ *p syst −A RK *p Act
wherein the following designations are used;
A THZ the effective hydraulic area of the master cylinder piston,
p syst the brake system pressure,
A RK the effective hydraulic area of a piston of the cylinder-piston arrangement, and
p Act the pressure provided by the pressure supply device.

Assignees

• Continental Teves Ag & Co Ohg

Inventors

• Drumm Stefan

Classifications

• B60T13/146

  Part of the system directly actuated by booster pressure · CPC title

• B60T13/662

  characterised by specified functions of the control system components · CPC title

• B60T13/745

  acting on a hydraulic system, e.g. a master cylinder · CPC title

• B60T8/4077 Primary

  Systems in which the booster is used as an auxiliary pressure source · CPC title

• B60T13/686

  in hydraulic systems or parts thereof · CPC title