Method for reducing drag torque fluctuations upon electric drive-off

Patent metadata

Field	Value
Publication number	US-9821788-B2
Application number	US-201514715256-A
Country	US
Kind code	B2
Filing date	May 18, 2015
Priority date	May 19, 2014
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A method is described for operating a motor vehicle, in which control is applied, in the context of a drive-off operation, to an electrical machine operable in motor mode in order to deliver a torque driving the vehicle, control simultaneously being applied to a braking system of the motor vehicle in such a way that it applies a braking torque.

First claim

What is claimed is:

1. A method for operating a motor vehicle, the method comprising:
controlling, in a drive-off operation, an electrical machine operable in a motor mode, to deliver a torque driving the vehicle; and
controlling simultaneously a braking system of the motor vehicle so that it applies a braking torque;
wherein control of the braking system occurs as a function of an actual speed value of the motor vehicle and as a function of a target speed value of the motor vehicle,
wherein control is applied in a braking manner to the braking system if the actual speed value is greater than the target speed value, and
wherein the torque delivered by the electrical machine, which is operable in a motor mode, contains a component dependent on an angle of a crankshaft of an internal combustion engine of the motor vehicle which counteracts variables that act in a crankshaft angle-independent manner on the torque to be delivered.

2. The method of claim 1 , wherein if there is an increase in a requested total torque, the braking torque is decreased, which is faster than increasing the driving torque of the electrical machine operable in a motor mode.

3. A method for operating a motor vehicle, the method comprising:
controlling, in a drive-off operation, an electrical machine operable in a motor mode, to deliver a torque driving the vehicle; and
controlling simultaneously a braking system of the motor vehicle so that it applies a braking torque;
wherein control of the braking system occurs as a function of an actual speed value of the motor vehicle and as a function of a target speed value of the motor vehicle,
wherein control is applied in a braking manner to the braking system if the actual speed value is greater than the target speed value, and
wherein control is applied to the electrical machine, which is operable in a motor mode, to deliver a torque, so that the torque delivered by it contains a component dependent on an angle of a crankshaft of an internal combustion engine which counteracts crankshaft angle-dependent fluctuations of a drag torque of the internal combustion engine.

4. The method of claim 3 , wherein the identification of the crankshaft angle-dependent component is accomplished by a torque pilot control.

5. A non-transitory machine-readable memory medium having a computer program, which is executable by a calculation unit, comprising:
a program code arrangement having program code for operating a motor vehicle, by performing the following:
control, in a drive-off operation, an electrical machine operable in a motor mode, to deliver a torque driving the vehicle; and
controlling simultaneously a braking system of the motor vehicle so that it applies a braking torque;
wherein application of control to the braking system occurs as a function of an actual speed value of the motor vehicle and as a function of a target speed value of the motor vehicle, and

wherein control is applied in a braking manner to the braking system if the actual speed value is greater than the target speed value, and
wherein the torque delivered by the electrical machine, which is operable in a motor mode, contains a component dependent on an angle of a crankshaft of an internal combustion engine of the motor vehicle which counteracts variables that act in a crankshaft angle-independent manner on the torque to be delivered.

6. The machine-readable memory medium of claim 5 , wherein if there is an increase in a requested total torque, the braking torque is decreased, which is faster than increasing the driving torque of the electrical machine operable in a motor mode.

Assignees

• Bosch Gmbh Robert

Inventors

• Trofimov Alexander
• Barth Michael

Classifications

• B60W2552/15

  Road slope, i.e. the inclination of a road segment in the longitudinal direction · CPC title

• B60W2720/10

  Longitudinal speed · CPC title

• B60W2510/0638

  Engine speed · CPC title

• B60W2530/10

  Weight · CPC title

• B60W2510/0676

  Engine temperature · CPC title