Method for braking of a motor vehicle

Patent metadata

Field	Value
Publication number	US-9242565-B2
Application number	US-201114237326-A
Country	US
Kind code	B2
Filing date	Nov 15, 2011
Priority date	Aug 25, 2011
Publication date	Jan 26, 2016
Grant date	Jan 26, 2016

Abstract

In a method for braking of a motor vehicle which is driven by a drive torque of at least one electrical machine electrically connected to an electric energy storage device, the at least one electrical machine is operated in a first operating mode as a generator for generating a generator braking torque. In a second operating mode, the at least one electrical machine is supplied with electrical energy from the energy storage device in such a way that a braking torque opposing the drive torque is generated by the at least one electrical machine.

First claim

The invention claimed is:

1. A method for braking of a motor vehicle, which is driven by a drive torque from at least one electric drive motor which is electrically connected to an electrical energy storage device, the method comprising:
in a first operating mode, operating the at least one electric drive motor as a generator for generating electric energy for supply to the energy storage device, and
in a second operating mode, supplying to the at least one electric drive motor the electrical energy from the energy storage device so as to generate a braking torque in opposition to the drive torque.

2. The method of claim 1 , wherein the first and second operating mode is set as a function of a state of charge of the energy storage device.

3. The method of claim 1 , further comprising adjusting a braking force generated by the at least one electric drive motor as a function of a position of a brake pedal of a friction brake of the motor vehicle.

4. The method of claim 3 , wherein the braking force is generated in a first region of a pedal travel of the brake pedal exclusively by the at least one electric drive motor.

5. The method of claim 3 , wherein the braking force is generated in a second region of a pedal travel of the brake pedal by the at least one electric drive motor and the friction brake.

6. The method of claim 5 , wherein the braking force generated by the at least one electric drive motor is substantially constant in the second region of the pedal travel.

7. The method of claim 1 , further comprising transition ing from the first operating mode to the second operating mode when a value characterizing a state of charge of the electric energy storage device exceeds a predetermined first threshold value.

8. The method of claim 7 , further comprising transitioning from the second operating mode to the first operating mode when a value characterizing a state of charge of the electric energy storage device falls below a predetermined second threshold value, wherein the second threshold value is smaller than the first threshold value.

9. The method of claim 1 , further comprising changing a polarity of electrical connections of the at least one electric drive motor for generating the braking torque.

10. The method of claim 1 , wherein the at least one electric drive motor for generating the braking torque comprises a three-phase drive motor, and wherein a frequency of a rotating field of a stator of the three-phase drive motor is changed for generating the braking torque.

11. A motor vehicle comprising:
at least one electric drive motor for generating a drive torque for the motor vehicle,
an electrical energy storage device which is electrically connected to the electrical drive motor,
a controller configured to operate the at least one electric drive motor as a generator for generating in a first operating mode electric enemy for supply to the energy storage device, and
a switching device for changing a polarity of the at least one electric drive motor, so that the electrical energy from the energy storage device is supplied in a second operating mode to the at least one electric drive motor for generating a braking torque in opposition the drive torque.

Assignees

• Kleickmann Bodo
• Meier Thomas-Willibald
• Audi Ag

Inventors

• Kleickmann Bodo
• Meier Thomas-Willibald

Classifications

• B60L7/14

  for vehicles propelled by AC motors · CPC title

• Y02T10/7005

  Cross-Sectional Technologies · mapped topic

• B60L7/12

  for vehicles propelled by DC motors · CPC title

• B60W2540/12

  Brake pedal position · CPC title

• B60L11/005

  Operations & Transport · mapped topic