Braking system of a motor vehicle and method for controlling the same

Patent metadata

Field	Value
Publication number	US-12090893-B2
Application number	US-202318507840-A
Country	US
Kind code	B2
Filing date	Nov 13, 2023
Priority date	Jun 7, 2021
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A braking system includes a service braking system having friction brakes actuatable by a pressure medium, an endurance braking system realized as a hydrodynamic or electrodynamic retarder, an electric machine connected to the wheels on an axle and operatable as a generator, and a foot-brake valve actuatable via a brake pedal. The braking-force demand signaled via a displacement of the pedal is satisfied, in order of priority, by the electric machine in generator operating mode, the retarder, and the service braking system. The distribution of the braking force to the components is communicated to a driver. To inform the driver about the distribution of the braking force, without this requiring the driver to look away from the traffic area ahead, in the case of a change in distribution of braking force, a haptically perceptible signal force is briefly superimposed, via the actuator, on a restoring force acting upon the pedal.

First claim

The invention claimed is:

1. A braking system of a motor vehicle having a vehicle axle and a plurality of wheels on said vehicle axle, the braking system comprising:
a service braking system having friction brakes configured to be actuated by a pressure medium;
an endurance braking system configured as a hydrodynamic or electrodynamic retarder;
at least one electric machine connected in a transmitting manner to the plurality of wheels on the vehicle axle, wherein said at least one electric machine is configured to be operated as a generator;
a foot-brake valve configured to be actuated via a brake pedal, said foot-brake valve having a braking-value transmitter and a brake-pedal actuator for generating a restoring force acting upon said brake pedal;
an electronic control device configured to control said hydrodynamic or electrodynamic retarder, said service braking system, and said at least one electric machine, wherein a braking-force demand that is signaled via a displacement of the brake pedal is satisfied, in order of priority, by said at least one electric machine operating as said generator, said hydrodynamic or electrodynamic retarder, and said service braking system, wherein a distribution of braking force to said at least one electric machine, said hydrodynamic or electrodynamic retarder, and said service braking system is communicated to a driver of the vehicle as a haptically perceptible signal force that is superimposed, via the brake-pedal actuator, on the restoring force acting upon the brake pedal;
said brake-pedal actuator being configured to operate electrically and including a rotationally or linearly displaceable transmission element; and,
said transmission element is connected in an actuating manner to a brake lever of said brake pedal.

2. The braking system of claim 1 , wherein said brake-pedal actuator is as an electric motor having a rotor shaft; and, said rotor shaft of said electric motor is connected in an actuating manner to said brake lever of said brake pedal.

3. The braking system of claim 1 , wherein said brake-pedal actuator is an electromagnet which is connected in an actuating manner to said brake lever of said brake pedal.

4. A method for controlling a braking system of a motor vehicle having a vehicle axle and a plurality of wheels on the vehicle axle, the braking system having a plurality of components including a service braking system, an endurance braking system, and at least one electric machine, the service braking system having friction brakes being configured to be actuated by a pressure medium, the endurance braking system being configured as a hydrodynamic or electrodynamic retarder, the at least one electric machine being connected in a transmitting manner to the plurality of wheels on the vehicle axle and configured to be operated at least as a generator, and a foot-brake valve configured to be actuated via a brake pedal, wherein the foot-brake valve has a braking-value transmitter and a brake-pedal actuator for generating a restoring force acting upon the brake pedal, wherein the method comprises:
controlling the plurality of components of the braking system via an electronic control device to satisfy a braking-force demand, in order of priority, by the electric machine in generator operating mode, by the retarder and by the service braking system; and,
communicating an occurrence of a distribution of a braking force to the plurality of components of the braking system to a driver of the motor vehicle through a haptically perceptible signal force that is superimposed, via the brake-pedal actuator, on the restoring force acting upon the brake pedal when there is a change in the distribution of the braking force to the components of the braking system.

5. The method of claim 4 further comprising:
when at least one of the plurality of components of the braking system is activated or deactivated, superimposing the haptically perceptible signal force on the restoring force acting upon the brake pedal via the brake-pedal actuator.

6. The method of claim 4 , wherein the haptically perceptible signal force that is superimposed on the restoring force acts as at least a pulse-type increase in the restoring force.

7. The method of claim 6 further comprising:
applying the haptically perceptible signal force in a form of pulse-type signal forces, wherein, when there is a change in the distribution of the braking force, at least one of the pulse-type signal forces differs from at least another one of the pulse-type signal forces with respect to at least one of number, strength, and duration.

8. The method of claim 4 further comprising applying the haptically perceptible signal force in a form of one or more oscillation sequences perceivable as a vibration on the brake pedal which each includes a plurality of oscillations of the restoring force.

9. The method of claim 8 , wherein, when there is a change in the distribution of the braking force, the oscillation sequence applied differs from another oscillation sequence of the one or more oscillation sequences with respect to at least one of frequency, amplitude, and duration.

10. The method of claim 4 , wherein a displacement of the brake pedal signals the braking-force demand.

Assignees

• Zf Cv Systems Global Gmbh

Inventors

• Heseding Johannes

Classifications

• B60W50/16

  Tactile feedback to the driver, e.g. vibration or force feedback to the driver on the steering wheel or the accelerator pedal · CPC title

• B60T13/586

  the retarders being of the electric type · CPC title

• B60T7/042

  by electrical means, e.g. using travel or force sensors · CPC title

• B60L2250/26

  by pedal actuation · CPC title

• B60L15/2009

  for braking · CPC title