Powertrain of a motor vehicle and method for controlling said powertrain

1. A motor vehicle powertrain comprising a controlled power source, a clutch, an automatically shifted transmission and a data transfer system enabling data to be exchanged between the component parts of the powertrain, an additional power source, and a control system for controlling said controlled power source and said additional power source on the basis of a comparison of the real behavior of the powertrain with a modeled behavior of a powertrain provided with a hydrodynamic torque converter, wherein the vehicle speed is determined in accordance with the following equation

V

Fahrzeug

=

r

reifen

*

∫

[

(

tq

eng

+

tq

ISG

)

*

μ

HTC

*

i

AT

*

i

Diff

-

tq

Fahrwid

]

theta

kfz

⁢

ⅆ

t

where:

μ HTC is the increased torque provided by the hydrodynamic tongue converter

i AT is the ear ratio of the automatic transmission

i Diff is the gear ratio of the differential

r reifen is the tire radius

theta kfz is the moment of inertia of the vehicle and is the theoretical driving torque.

2. The powertrain according to claim 1 , wherein

the controlled power source is an internal combustion engine;

the additional power source is a crankshaft starter/generator,

the clutch is implemented as an automatically actuated friction clutch, and

there is provided a feedback loop for simulating the behavior of a torque converter.

3. The powertrain according to claim 2 , wherein the control system contains

a conversion block for converting a required wheel torque to a crankshaft torque on the basis of a correction value, and

a correction device in which the correction value for the torque is generated.

4. The powertrain according to claim 1 , wherein the control system contains

a conversion block for converting a required wheel torque to a crankshaft torque on the basis of a correction value, and

a correction device in which the correction value for the torque is generated.

5. The powertrain according to claim 1 , wherein the control system has a torque divider for splitting the power source torque between the power source and the additional power source.

6. The powertrain according to claim 1 , wherein the control system has an observer block which represents a model of a powertrain having a hydrodynamic torque converter and is used to calculate a vehicle speed corresponding to the speed assumed by a comparable motor vehicle provided with a hydrodynamic torque converter and an automatic transmission in response to the same driver input.

7. A motor vehicle powertrain comprising a controlled power source, a clutch, an automatically shifted transmission and a data transfer system enabling data to be exchanged between the component parts of the powertrain, an additional power source, and a control system for controlling said controlled power source and said additional power source on the basis of a comparison of the real behavior of the powertrain with a modeled behavior of a powertrain provided with a hydrodynamic torque converter, wherein the required driving torque for the powertrain is determined according to the following equation

(

tq

eng

+

tq

ISG

)

=

tq

wheel

slip

clut

⁢

⁢

ch

*

i

AMT

*

i

Diff

*

k

pid

where:

i AMT = 1AT is the gear ratio of the automatic transmission

i Diff is the gear ratio of the differential is the correction factor

Slip clutch is the clutch slip

tq eng is the actual torque of the internal combustion engine

tq ISG is the actual torque of the crankshaft starter/generator

tq wheel is the wheel torque.

8. A method for controlling a powertrain comprising a controlled power source, a clutch, an automatically shifted transmission and a data transfer system enabling data to be exchanged between the component parts of the powertrain, an additional power source, and a control system comprising the step of:

controlling said controlled power source and said additional power source to simulate the behavior of a hydrodynamic torque converter by means of a comparison of a real behavior of the powertrain with a modeled behavior of a powertrain provided with a hydrodynamic torque converter, wherein the vehicle speed is determined in accordance with the following equation

V

Fahrzeug

=

r

reifen

*

∫

[

(

tq

eng

+

tq

ISG

)

*

μ

HTC

*

i

AT

*

i

Diff

-

tq

Fahrwid

]

theta

kfz

⁢

ⅆ

t

where:

μHTC is the increased torque provided by the hydrodynamic torque converter

i AT is the ear ratio of the automatic transmission

i Diff is the sear ratio of the differential

r reifen is the tire radius

theta kfz is the moment of inertia of the vehicle and

tq Fahrwid is the rolling resistance

(tg eng +Tq ISG )′ is the theoretical driving torque.

9. The method according to claim 8 , wherein a conversion block performs a conversion of a required wheel torque to a powertrain torque on the basis of a correction value and that the powertrain torque is divided between the power source and the additional power source.

10. The method according to claim 9 , wherein a demanded torque is converted to a necessary torque at the crankshaft of the power source using the gear ratios of the powertrain components.

11. The method according to claim 8 , wherein a demanded torque is converted to a necessary torque at the crankshaft of the power source using the gear ratios of the powertrain components.

12. The method according to claim 8 , comprising the step of splitting the power source torque between the power source and the additional power source by a torque divider.

13. The method according to claim 8 , comprising the steps of:

representing a model of a powertrain having a hydrodynamic torque converter by an observer block and

using the model to calculate a vehicle speed corresponding to the speed assumed by a comparable motor vehicle provided with a hydrodynamic torque converter and an automatic transmission in response to the same driver input.

14. A method for controlling a powertrain comprising a controlled power source, a clutch, an automatically shifted transmission and a data transfer system enabling data to be exchanged between the component parts of the powertrain, an additional power source, and a control system comprising the step of:

controlling said controlled power source and said additional power source to simulate the behavior of a hydrodynamic torque converter by means of a comparison of a real behavior of the powertrain with a modeled behavior of a powertrain provided with a hydrodynamic torque converter, wherein the required driving torque for the powertrain is determined according to the following equation

(

tq

eng

+

tq

ISG

)

=

tq

wheel

slip

clut

⁢

⁢

ch

*

i

AMT

*

i

Diff

*

k

pid

where:

i AMT =i AT is the gear ratio of the automatic transmission

i Diff is the gear ratio of the differential

k pid is the correction factor

slip clutch is the clutch slip

tq eng is the actual torque of the internal combustion engine

tq ISG is the actual torque of the crankshaft starter/generator

tq wheel is the wheel torque.